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7 @settitle GNU Guix Reference Manual
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112 Permission is granted to copy, distribute and/or modify this document
113 under the terms of the GNU Free Documentation License, Version 1.3 or
114 any later version published by the Free Software Foundation; with no
115 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
116 copy of the license is included in the section entitled ``GNU Free
117 Documentation License''.
120 @dircategory System administration
122 * Guix: (guix). Manage installed software and system configuration.
123 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
124 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
125 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
126 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
127 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
130 @dircategory Software development
132 * guix shell: (guix)Invoking guix shell. Creating software environments.
133 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
134 * guix build: (guix)Invoking guix build. Building packages.
135 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
139 @title GNU Guix Reference Manual
140 @subtitle Using the GNU Guix Functional Package Manager
141 @author The GNU Guix Developers
144 @vskip 0pt plus 1filll
145 Edition @value{EDITION} @*
153 @c *********************************************************************
157 This document describes GNU Guix version @value{VERSION}, a functional
158 package management tool written for the GNU system.
160 @c TRANSLATORS: You can replace the following paragraph with information on
161 @c how to join your own translation team and how to report issues with the
163 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
164 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
165 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
166 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
167 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
168 would like to translate it in your native language, consider joining
169 @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
170 Weblate} (@pxref{Translating Guix}).
173 * Introduction:: What is Guix about?
174 * Installation:: Installing Guix.
175 * System Installation:: Installing the whole operating system.
176 * System Troubleshooting Tips:: When things don't go as planned.
177 * Getting Started:: Your first steps.
178 * Package Management:: Package installation, upgrade, etc.
179 * Channels:: Customizing the package collection.
180 * Development:: Guix-aided software development.
181 * Programming Interface:: Using Guix in Scheme.
182 * Utilities:: Package management commands.
183 * Foreign Architectures:: Build for foreign architectures.
184 * System Configuration:: Configuring the operating system.
185 * Home Configuration:: Configuring the home environment.
186 * Documentation:: Browsing software user manuals.
187 * Platforms:: Defining platforms.
188 * System Images:: Creating system images.
189 * Installing Debugging Files:: Feeding the debugger.
190 * Using TeX and LaTeX:: Typesetting.
191 * Security Updates:: Deploying security fixes quickly.
192 * Bootstrapping:: GNU/Linux built from scratch.
193 * Porting:: Targeting another platform or kernel.
194 * Contributing:: Your help needed!
196 * Acknowledgments:: Thanks!
197 * GNU Free Documentation License:: The license of this manual.
198 * Concept Index:: Concepts.
199 * Programming Index:: Data types, functions, and variables.
202 --- The Detailed Node Listing ---
206 * Managing Software the Guix Way:: What's special.
207 * GNU Distribution:: The packages and tools.
211 * Binary Installation:: Getting Guix running in no time!
212 * Requirements:: Software needed to build and run Guix.
213 * Running the Test Suite:: Testing Guix.
214 * Setting Up the Daemon:: Preparing the build daemon's environment.
215 * Invoking guix-daemon:: Running the build daemon.
216 * Application Setup:: Application-specific setup.
217 * Upgrading Guix:: Upgrading Guix and its build daemon.
219 Setting Up the Daemon
221 * Build Environment Setup:: Preparing the isolated build environment.
222 * Daemon Offload Setup:: Offloading builds to remote machines.
223 * SELinux Support:: Using an SELinux policy for the daemon.
227 * Limitations:: What you can expect.
228 * Hardware Considerations:: Supported hardware.
229 * USB Stick and DVD Installation:: Preparing the installation medium.
230 * Preparing for Installation:: Networking, partitioning, etc.
231 * Guided Graphical Installation:: Easy graphical installation.
232 * Manual Installation:: Manual installation for wizards.
233 * After System Installation:: When installation succeeded.
234 * Installing Guix in a VM:: Guix System playground.
235 * Building the Installation Image:: How this comes to be.
237 System Troubleshooting Tips
239 * Chrooting into an existing system:: Fixing things from a chroot
243 * Keyboard Layout and Networking and Partitioning:: Initial setup.
244 * Proceeding with the Installation:: Installing.
248 * Features:: How Guix will make your life brighter.
249 * Invoking guix package:: Package installation, removal, etc.
250 * Substitutes:: Downloading pre-built binaries.
251 * Packages with Multiple Outputs:: Single source package, multiple outputs.
252 * Invoking guix gc:: Running the garbage collector.
253 * Invoking guix pull:: Fetching the latest Guix and distribution.
254 * Invoking guix time-machine:: Running an older revision of Guix.
255 * Inferiors:: Interacting with another revision of Guix.
256 * Invoking guix describe:: Display information about your Guix revision.
257 * Invoking guix archive:: Exporting and importing store files.
261 * Official Substitute Servers:: One particular source of substitutes.
262 * Substitute Server Authorization:: How to enable or disable substitutes.
263 * Getting Substitutes from Other Servers:: Substitute diversity.
264 * Substitute Authentication:: How Guix verifies substitutes.
265 * Proxy Settings:: How to get substitutes via proxy.
266 * Substitution Failure:: What happens when substitution fails.
267 * On Trusting Binaries:: How can you trust that binary blob?
271 * Specifying Additional Channels:: Extending the package collection.
272 * Using a Custom Guix Channel:: Using a customized Guix.
273 * Replicating Guix:: Running the @emph{exact same} Guix.
274 * Channel Authentication:: How Guix verifies what it fetches.
275 * Channels with Substitutes:: Using channels with available substitutes.
276 * Creating a Channel:: How to write your custom channel.
277 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
278 * Declaring Channel Dependencies:: How to depend on other channels.
279 * Specifying Channel Authorizations:: Defining channel authors authorizations.
280 * Primary URL:: Distinguishing mirror to original.
281 * Writing Channel News:: Communicating information to channel's users.
285 * Invoking guix shell:: Spawning one-off software environments.
286 * Invoking guix environment:: Setting up development environments.
287 * Invoking guix pack:: Creating software bundles.
288 * The GCC toolchain:: Working with languages supported by GCC.
289 * Invoking guix git authenticate:: Authenticating Git repositories.
291 Programming Interface
293 * Package Modules:: Packages from the programmer's viewpoint.
294 * Defining Packages:: Defining new packages.
295 * Defining Package Variants:: Customizing packages.
296 * Writing Manifests:: The bill of materials of your environment.
297 * Build Systems:: Specifying how packages are built.
298 * Build Phases:: Phases of the build process of a package.
299 * Build Utilities:: Helpers for your package definitions and more.
300 * Search Paths:: Declaring search path environment variables.
301 * The Store:: Manipulating the package store.
302 * Derivations:: Low-level interface to package derivations.
303 * The Store Monad:: Purely functional interface to the store.
304 * G-Expressions:: Manipulating build expressions.
305 * Invoking guix repl:: Programming Guix in Guile.
306 * Using Guix Interactively:: Fine-grain interaction at the REPL.
310 * package Reference:: The package data type.
311 * origin Reference:: The origin data type.
315 * Invoking guix build:: Building packages from the command line.
316 * Invoking guix edit:: Editing package definitions.
317 * Invoking guix download:: Downloading a file and printing its hash.
318 * Invoking guix hash:: Computing the cryptographic hash of a file.
319 * Invoking guix import:: Importing package definitions.
320 * Invoking guix refresh:: Updating package definitions.
321 * Invoking guix style:: Styling package definitions.
322 * Invoking guix lint:: Finding errors in package definitions.
323 * Invoking guix size:: Profiling disk usage.
324 * Invoking guix graph:: Visualizing the graph of packages.
325 * Invoking guix publish:: Sharing substitutes.
326 * Invoking guix challenge:: Challenging substitute servers.
327 * Invoking guix copy:: Copying to and from a remote store.
328 * Invoking guix container:: Process isolation.
329 * Invoking guix weather:: Assessing substitute availability.
330 * Invoking guix processes:: Listing client processes.
332 Invoking @command{guix build}
334 * Common Build Options:: Build options for most commands.
335 * Package Transformation Options:: Creating variants of packages.
336 * Additional Build Options:: Options specific to 'guix build'.
337 * Debugging Build Failures:: Real life packaging experience.
339 Foreign Architectures
340 * Cross-Compilation:: Cross-compiling for another architecture.
341 * Native Builds:: Targeting another architecture through native builds.
345 * Using the Configuration System:: Customizing your GNU system.
346 * operating-system Reference:: Detail of operating-system declarations.
347 * File Systems:: Configuring file system mounts.
348 * Mapped Devices:: Block device extra processing.
349 * Swap Space:: Backing RAM with disk space.
350 * User Accounts:: Specifying user accounts.
351 * Keyboard Layout:: How the system interprets key strokes.
352 * Locales:: Language and cultural convention settings.
353 * Services:: Specifying system services.
354 * Setuid Programs:: Programs running with elevated privileges.
355 * X.509 Certificates:: Authenticating HTTPS servers.
356 * Name Service Switch:: Configuring libc's name service switch.
357 * Initial RAM Disk:: Linux-Libre bootstrapping.
358 * Bootloader Configuration:: Configuring the boot loader.
359 * Invoking guix system:: Instantiating a system configuration.
360 * Invoking guix deploy:: Deploying a system configuration to a remote host.
361 * Running Guix in a VM:: How to run Guix System in a virtual machine.
362 * Defining Services:: Adding new service definitions.
364 Home Environment Configuration
366 * Invoking guix home:: Instantiating a home environment configuration.
370 * Base Services:: Essential system services.
371 * Scheduled Job Execution:: The mcron service.
372 * Log Rotation:: The rottlog service.
373 * Networking Setup:: Setting up network interfaces.
374 * Networking Services:: Firewall, SSH daemon, etc.
375 * Unattended Upgrades:: Automated system upgrades.
376 * X Window:: Graphical display.
377 * Printing Services:: Local and remote printer support.
378 * Desktop Services:: D-Bus and desktop services.
379 * Sound Services:: ALSA and Pulseaudio services.
380 * Database Services:: SQL databases, key-value stores, etc.
381 * Mail Services:: IMAP, POP3, SMTP, and all that.
382 * Messaging Services:: Messaging services.
383 * Telephony Services:: Telephony services.
384 * Monitoring Services:: Monitoring services.
385 * Kerberos Services:: Kerberos services.
386 * LDAP Services:: LDAP services.
387 * Web Services:: Web servers.
388 * Certificate Services:: TLS certificates via Let's Encrypt.
389 * DNS Services:: DNS daemons.
390 * VPN Services:: VPN daemons.
391 * Network File System:: NFS related services.
392 * Samba Services:: Samba services.
393 * Continuous Integration:: Cuirass and Laminar services.
394 * Power Management Services:: Extending battery life.
395 * Audio Services:: The MPD.
396 * Virtualization Services:: Virtualization services.
397 * Version Control Services:: Providing remote access to Git repositories.
398 * Game Services:: Game servers.
399 * PAM Mount Service:: Service to mount volumes when logging in.
400 * Guix Services:: Services relating specifically to Guix.
401 * Linux Services:: Services tied to the Linux kernel.
402 * Hurd Services:: Services specific for a Hurd System.
403 * Miscellaneous Services:: Other services.
407 * Service Composition:: The model for composing services.
408 * Service Types and Services:: Types and services.
409 * Service Reference:: API reference.
410 * Shepherd Services:: A particular type of service.
411 * Complex Configurations:: Defining bindings for complex configurations.
415 * platform Reference:: Detail of platform declarations.
416 * Supported Platforms:: Description of the supported platforms.
420 * image Reference:: Detail of image declarations.
421 * Instantiate an Image:: How to instantiate an image record.
422 * image-type Reference:: Detail of image types declaration.
423 * Image Modules:: Definition of image modules.
425 Installing Debugging Files
427 * Separate Debug Info:: Installing 'debug' outputs.
428 * Rebuilding Debug Info:: Building missing debug info.
432 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
433 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
438 @c *********************************************************************
440 @chapter Introduction
443 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
444 using the international phonetic alphabet (IPA).} is a package
445 management tool for and distribution of the GNU system.
446 Guix makes it easy for unprivileged
447 users to install, upgrade, or remove software packages, to roll back to a
448 previous package set, to build packages from source, and generally
449 assists with the creation and maintenance of software environments.
452 @cindex GuixSD, now Guix System
453 @cindex Guix System Distribution, now Guix System
454 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
455 complements the available tools without interference (@pxref{Installation}),
456 or you can use it as a standalone operating system distribution,
457 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
458 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
459 group everything under the ``Guix'' banner since, after all, Guix System is
460 readily available through the @command{guix system} command, even if you're
461 using a different distro underneath!}. @xref{GNU Distribution}.
464 * Managing Software the Guix Way:: What's special.
465 * GNU Distribution:: The packages and tools.
468 @node Managing Software the Guix Way
469 @section Managing Software the Guix Way
471 @cindex user interfaces
472 Guix provides a command-line package management interface
473 (@pxref{Package Management}), tools to help with software development
474 (@pxref{Development}), command-line utilities for more advanced usage
475 (@pxref{Utilities}), as well as Scheme programming interfaces
476 (@pxref{Programming Interface}).
478 Its @dfn{build daemon} is responsible for building packages on behalf of
479 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
480 binaries from authorized sources (@pxref{Substitutes}).
482 @cindex extensibility of the distribution
483 @cindex customization, of packages
484 Guix includes package definitions for many GNU and non-GNU packages, all
485 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
486 user's computing freedom}. It is @emph{extensible}: users can write
487 their own package definitions (@pxref{Defining Packages}) and make them
488 available as independent package modules (@pxref{Package Modules}). It
489 is also @emph{customizable}: users can @emph{derive} specialized package
490 definitions from existing ones, including from the command line
491 (@pxref{Package Transformation Options}).
493 @cindex functional package management
495 Under the hood, Guix implements the @dfn{functional package management}
496 discipline pioneered by Nix (@pxref{Acknowledgments}).
497 In Guix, the package build and installation process is seen
498 as a @emph{function}, in the mathematical sense. That function takes inputs,
499 such as build scripts, a compiler, and libraries, and
500 returns an installed package. As a pure function, its result depends
501 solely on its inputs---for instance, it cannot refer to software or
502 scripts that were not explicitly passed as inputs. A build function
503 always produces the same result when passed a given set of inputs. It
504 cannot alter the environment of the running system in
505 any way; for instance, it cannot create, modify, or delete files outside
506 of its build and installation directories. This is achieved by running
507 build processes in isolated environments (or @dfn{containers}), where only their
508 explicit inputs are visible.
511 The result of package build functions is @dfn{cached} in the file
512 system, in a special directory called @dfn{the store} (@pxref{The
513 Store}). Each package is installed in a directory of its own in the
514 store---by default under @file{/gnu/store}. The directory name contains
515 a hash of all the inputs used to build that package; thus, changing an
516 input yields a different directory name.
518 This approach is the foundation for the salient features of Guix: support
519 for transactional package upgrade and rollback, per-user installation, and
520 garbage collection of packages (@pxref{Features}).
523 @node GNU Distribution
524 @section GNU Distribution
527 Guix comes with a distribution of the GNU system consisting entirely of
528 free software@footnote{The term ``free'' here refers to the
529 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
530 users of that software}.}. The
531 distribution can be installed on its own (@pxref{System Installation}),
532 but it is also possible to install Guix as a package manager on top of
533 an installed GNU/Linux system (@pxref{Installation}). When we need to
534 distinguish between the two, we refer to the standalone distribution as
537 The distribution provides core GNU packages such as GNU libc, GCC, and
538 Binutils, as well as many GNU and non-GNU applications. The complete
539 list of available packages can be browsed
540 @url{https://www.gnu.org/software/guix/packages,on-line} or by
541 running @command{guix package} (@pxref{Invoking guix package}):
544 guix package --list-available
547 Our goal is to provide a practical 100% free software distribution of
548 Linux-based and other variants of GNU, with a focus on the promotion and
549 tight integration of GNU components, and an emphasis on programs and
550 tools that help users exert that freedom.
552 Packages are currently available on the following platforms:
557 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
560 Intel 32-bit architecture (IA32), Linux-Libre kernel.
563 ARMv7-A architecture with hard float, Thumb-2 and NEON,
564 using the EABI hard-float application binary interface (ABI),
565 and Linux-Libre kernel.
568 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
571 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
574 This configuration is experimental and under development. The easiest
575 way for you to give it a try is by setting up an instance of
576 @code{hurd-vm-service-type} on your GNU/Linux machine
577 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
578 @xref{Contributing}, on how to help!
580 @item mips64el-linux (unsupported)
581 little-endian 64-bit MIPS processors, specifically the Loongson series,
582 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
583 supported; in particular, there is no ongoing work to ensure that this
584 architecture still works. Should someone decide they wish to revive this
585 architecture then the code is still available.
587 @item powerpc-linux (unsupported)
588 big-endian 32-bit PowerPC processors, specifically the PowerPC G4 with
589 AltiVec support, and Linux-Libre kernel. This configuration is not
590 fully supported and there is no ongoing work to ensure this architecture
593 @item powerpc64le-linux
594 little-endian 64-bit Power ISA processors, Linux-Libre kernel. This
595 includes POWER9 systems such as the
596 @uref{https://www.fsf.org/news/talos-ii-mainboard-and-talos-ii-lite-mainboard-now-fsf-certified-to-respect-your-freedom,
597 RYF Talos II mainboard}. This platform is available as a "technology
598 preview": although it is supported, substitutes are not yet available
599 from the build farm (@pxref{Substitutes}), and some packages may fail to
600 build (@pxref{Tracking Bugs and Patches}). That said, the Guix
601 community is actively working on improving this support, and now is a
602 great time to try it and get involved!
605 little-endian 64-bit RISC-V processors, specifically RV64GC, and
606 Linux-Libre kernel. This platform is available as a "technology preview":
607 although it is supported, substitutes are not yet available from the
608 build farm (@pxref{Substitutes}), and some packages may fail to build
609 (@pxref{Tracking Bugs and Patches}). That said, the Guix community is
610 actively working on improving this support, and now is a great time to
611 try it and get involved!
615 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
616 configuration and Guix takes care of instantiating the configuration in a
617 transactional, reproducible, and stateless fashion (@pxref{System
618 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
619 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
620 Manual}), the well-known GNU utilities and tool chain, as well as the
621 graphical environment or system services of your choice.
623 Guix System is available on all the above platforms except
624 @code{mips64el-linux}, @code{powerpc-linux}, @code{powerpc64le-linux} and
625 @code{riscv64-linux}.
628 For information on porting to other architectures or kernels,
631 Building this distribution is a cooperative effort, and you are invited
632 to join! @xref{Contributing}, for information about how you can help.
635 @c *********************************************************************
637 @chapter Installation
639 @cindex installing Guix
642 We recommend the use of this
643 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
644 shell installer script} to install Guix on top of a running GNU/Linux system,
645 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
646 with the installation of the package manager, which can be done on top of a
647 running GNU/Linux system. If, instead, you want to install the complete GNU
648 operating system, @pxref{System Installation}.} The script automates the
649 download, installation, and initial configuration of Guix. It should be run
653 @cindex foreign distro
654 @cindex directories related to foreign distro
655 When installed on a foreign distro, GNU@tie{}Guix complements the available
656 tools without interference. Its data lives exclusively in two directories,
657 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
658 such as @file{/etc}, are left untouched.
660 Once installed, Guix can be updated by running @command{guix pull}
661 (@pxref{Invoking guix pull}).
663 If you prefer to perform the installation steps manually or want to tweak
664 them, you may find the following subsections useful. They describe the
665 software requirements of Guix, as well as how to install it manually and get
669 * Binary Installation:: Getting Guix running in no time!
670 * Requirements:: Software needed to build and run Guix.
671 * Running the Test Suite:: Testing Guix.
672 * Setting Up the Daemon:: Preparing the build daemon's environment.
673 * Invoking guix-daemon:: Running the build daemon.
674 * Application Setup:: Application-specific setup.
675 * Upgrading Guix:: Upgrading Guix and its build daemon.
678 @node Binary Installation
679 @section Binary Installation
681 @cindex installing Guix from binaries
682 @cindex installer script
683 This section describes how to install Guix on an arbitrary system from a
684 self-contained tarball providing binaries for Guix and for all its
685 dependencies. This is often quicker than installing from source, which
686 is described in the next sections. The only requirement is to have
689 @c Note duplicated from the ``Installation'' node.
691 We recommend the use of this
692 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
693 shell installer script}. The script automates the download, installation, and
694 initial configuration steps described below. It should be run as the root
695 user. As root, you can thus run this:
699 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
700 chmod +x guix-install.sh
704 If you're running Debian or a derivative such as Ubuntu, you can instead
705 install the package (it might be a version older than @value{VERSION}
706 but you can update it afterwards by running @samp{guix pull}):
709 sudo apt install guix
712 Likewise on openSUSE:
715 sudo zypper install guix
718 When you're done, @pxref{Application Setup} for extra configuration you
719 might need, and @ref{Getting Started} for your first steps!
722 Installing goes along these lines:
726 @cindex downloading Guix binary
727 Download the binary tarball from
728 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
729 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
730 @code{i686} (32-bits) machine already running the kernel Linux, and so on
731 (@pxref{GNU Distribution}).
733 @c The following is somewhat duplicated in ``System Installation''.
734 Make sure to download the associated @file{.sig} file and to verify the
735 authenticity of the tarball against it, along these lines:
738 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
739 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
742 If that command fails because you do not have the required public key,
743 then run this command to import it:
746 $ wget '@value{OPENPGP-SIGNING-KEY-URL}' \
747 -qO - | gpg --import -
751 and rerun the @code{gpg --verify} command.
753 Take note that a warning like ``This key is not certified with a trusted
754 signature!'' is normal.
756 @c end authentication part
759 Now, you need to become the @code{root} user. Depending on your distribution,
760 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
764 # tar --warning=no-timestamp -xf \
765 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
766 # mv var/guix /var/ && mv gnu /
769 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
770 The latter contains a ready-to-use profile for @code{root} (see next
773 Do @emph{not} unpack the tarball on a working Guix system since that
774 would overwrite its own essential files.
776 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
777 not emit warnings about ``implausibly old time stamps'' (such
778 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
780 They stem from the fact that all the
781 files in the archive have their modification time set to 1 (which
782 means January 1st, 1970). This is done on purpose to make sure the
783 archive content is independent of its creation time, thus making it
787 Make the profile available under @file{~root/.config/guix/current}, which is
788 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
791 # mkdir -p ~root/.config/guix
792 # ln -sf /var/guix/profiles/per-user/root/current-guix \
793 ~root/.config/guix/current
796 Source @file{etc/profile} to augment @env{PATH} and other relevant
797 environment variables:
800 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
801 source $GUIX_PROFILE/etc/profile
805 Create the group and user accounts for build users as explained below
806 (@pxref{Build Environment Setup}).
809 Run the daemon, and set it to automatically start on boot.
811 If your host distro uses the systemd init system, this can be achieved
814 @c Versions of systemd that supported symlinked service files are not
815 @c yet widely deployed, so we should suggest that users copy the service
818 @c See this thread for more information:
819 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
822 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
823 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
825 # systemctl enable --now gnu-store.mount guix-daemon
828 You may also want to arrange for @command{guix gc} to run periodically:
831 # cp ~root/.config/guix/current/lib/systemd/system/guix-gc.service \
832 ~root/.config/guix/current/lib/systemd/system/guix-gc.timer \
834 # systemctl enable --now guix-gc.timer
837 You may want to edit @file{guix-gc.service} to adjust the command line
838 options to fit your needs (@pxref{Invoking guix gc}).
840 If your host distro uses the Upstart init system:
843 # initctl reload-configuration
844 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
849 Otherwise, you can still start the daemon manually with:
852 # ~root/.config/guix/current/bin/guix-daemon \
853 --build-users-group=guixbuild
857 Make the @command{guix} command available to other users on the machine,
861 # mkdir -p /usr/local/bin
863 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
866 It is also a good idea to make the Info version of this manual available
870 # mkdir -p /usr/local/share/info
871 # cd /usr/local/share/info
872 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
876 That way, assuming @file{/usr/local/share/info} is in the search path,
877 running @command{info guix} will open this manual (@pxref{Other Info
878 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
882 @cindex substitutes, authorization thereof
883 To use substitutes from @code{@value{SUBSTITUTE-SERVER-1}},
884 @code{@value{SUBSTITUTE-SERVER-2}} or a mirror (@pxref{Substitutes}),
888 # guix archive --authorize < \
889 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER-1}.pub
890 # guix archive --authorize < \
891 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER-2}.pub
895 If you do not enable substitutes, Guix will end up building
896 @emph{everything} from source on your machine, making each installation
897 and upgrade very expensive. @xref{On Trusting Binaries}, for a
898 discussion of reasons why one might want do disable substitutes.
902 Each user may need to perform a few additional steps to make their Guix
903 environment ready for use, @pxref{Application Setup}.
906 Voilà, the installation is complete!
908 You can confirm that Guix is working by installing a sample package into
915 The binary installation tarball can be (re)produced and verified simply
916 by running the following command in the Guix source tree:
919 make guix-binary.@var{system}.tar.xz
923 ...@: which, in turn, runs:
926 guix pack -s @var{system} --localstatedir \
927 --profile-name=current-guix guix
930 @xref{Invoking guix pack}, for more info on this handy tool.
933 @section Requirements
935 This section lists requirements when building Guix from source. The
936 build procedure for Guix is the same as for other GNU software, and is
937 not covered here. Please see the files @file{README} and @file{INSTALL}
938 in the Guix source tree for additional details.
940 @cindex official website
941 GNU Guix is available for download from its website at
942 @url{https://www.gnu.org/software/guix/}.
944 GNU Guix depends on the following packages:
947 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x,
948 version 3.0.3 or later;
949 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
952 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
953 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
954 Guile,, gnutls-guile, GnuTLS-Guile});
956 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
958 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib},
959 version 0.1.0 or later;
960 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
961 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
963 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.5.0
965 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
967 @item @url{https://www.gnu.org/software/make/, GNU Make}.
970 The following dependencies are optional:
974 @c Note: We need at least 0.13.0 for #:nodelay.
975 Support for build offloading (@pxref{Daemon Offload Setup}) and
976 @command{guix copy} (@pxref{Invoking guix copy}) depends on
977 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
978 version 0.13.0 or later.
981 @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
982 compression and decompression in @command{guix publish} and for
983 substitutes (@pxref{Invoking guix publish}).
986 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
987 the @code{crate} importer (@pxref{Invoking guix import}).
990 @uref{https://www.nongnu.org/guile-lib/doc/ref/htmlprag/, Guile-Lib} for
991 the @code{go} importer (@pxref{Invoking guix import}) and for some of
992 the ``updaters'' (@pxref{Invoking guix refresh}).
995 When @url{http://www.bzip.org, libbz2} is available,
996 @command{guix-daemon} can use it to compress build logs.
999 Unless @option{--disable-daemon} was passed to @command{configure}, the
1000 following packages are also needed:
1003 @item @url{https://gnupg.org/, GNU libgcrypt};
1004 @item @url{https://sqlite.org, SQLite 3};
1005 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
1009 @cindex state directory
1010 When configuring Guix on a system that already has a Guix installation,
1011 be sure to specify the same state directory as the existing installation
1012 using the @option{--localstatedir} option of the @command{configure}
1013 script (@pxref{Directory Variables, @code{localstatedir},, standards,
1014 GNU Coding Standards}). Usually, this @var{localstatedir} option is
1015 set to the value @file{/var}. The @command{configure} script protects
1016 against unintended misconfiguration of @var{localstatedir} so you do not
1017 inadvertently corrupt your store (@pxref{The Store}).
1019 @node Running the Test Suite
1020 @section Running the Test Suite
1023 After a successful @command{configure} and @code{make} run, it is a good
1024 idea to run the test suite. It can help catch issues with the setup or
1025 environment, or bugs in Guix itself---and really, reporting test
1026 failures is a good way to help improve the software. To run the test
1033 Test cases can run in parallel: you can use the @code{-j} option of
1034 GNU@tie{}make to speed things up. The first run may take a few minutes
1035 on a recent machine; subsequent runs will be faster because the store
1036 that is created for test purposes will already have various things in
1039 It is also possible to run a subset of the tests by defining the
1040 @code{TESTS} makefile variable as in this example:
1043 make check TESTS="tests/store.scm tests/cpio.scm"
1046 By default, tests results are displayed at a file level. In order to
1047 see the details of every individual test cases, it is possible to define
1048 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
1051 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
1054 The underlying SRFI 64 custom Automake test driver used for the 'check'
1055 test suite (located at @file{build-aux/test-driver.scm}) also allows
1056 selecting which test cases to run at a finer level, via its
1057 @option{--select} and @option{--exclude} options. Here's an example, to
1058 run all the test cases from the @file{tests/packages.scm} test file
1059 whose names start with ``transaction-upgrade-entry'':
1062 export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
1063 make check TESTS="tests/packages.scm"
1066 Those wishing to inspect the results of failed tests directly from the
1067 command line can add the @option{--errors-only=yes} option to the
1068 @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
1069 Automake makefile variable, as in:
1072 make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
1075 The @option{--show-duration=yes} option can be used to print the
1076 duration of the individual test cases, when used in combination with
1077 @option{--brief=no}:
1080 make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
1083 @xref{Parallel Test Harness,,,automake,GNU Automake} for more
1084 information about the Automake Parallel Test Harness.
1086 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
1087 @file{test-suite.log} file. Please specify the Guix version being used
1088 as well as version numbers of the dependencies (@pxref{Requirements}) in
1091 Guix also comes with a whole-system test suite that tests complete
1092 Guix System instances. It can only run on systems where
1093 Guix is already installed, using:
1100 or, again, by defining @code{TESTS} to select a subset of tests to run:
1103 make check-system TESTS="basic mcron"
1106 These system tests are defined in the @code{(gnu tests @dots{})}
1107 modules. They work by running the operating systems under test with
1108 lightweight instrumentation in a virtual machine (VM). They can be
1109 computationally intensive or rather cheap, depending on whether
1110 substitutes are available for their dependencies (@pxref{Substitutes}).
1111 Some of them require a lot of storage space to hold VM images.
1113 Again in case of test failures, please send @email{bug-guix@@gnu.org}
1116 @node Setting Up the Daemon
1117 @section Setting Up the Daemon
1120 Operations such as building a package or running the garbage collector
1121 are all performed by a specialized process, the @dfn{build daemon}, on
1122 behalf of clients. Only the daemon may access the store and its
1123 associated database. Thus, any operation that manipulates the store
1124 goes through the daemon. For instance, command-line tools such as
1125 @command{guix package} and @command{guix build} communicate with the
1126 daemon (@i{via} remote procedure calls) to instruct it what to do.
1128 The following sections explain how to prepare the build daemon's
1129 environment. See also @ref{Substitutes}, for information on how to allow
1130 the daemon to download pre-built binaries.
1133 * Build Environment Setup:: Preparing the isolated build environment.
1134 * Daemon Offload Setup:: Offloading builds to remote machines.
1135 * SELinux Support:: Using an SELinux policy for the daemon.
1138 @node Build Environment Setup
1139 @subsection Build Environment Setup
1141 @cindex build environment
1142 In a standard multi-user setup, Guix and its daemon---the
1143 @command{guix-daemon} program---are installed by the system
1144 administrator; @file{/gnu/store} is owned by @code{root} and
1145 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
1146 Guix tools to build packages or otherwise access the store, and the
1147 daemon will do it on their behalf, ensuring that the store is kept in a
1148 consistent state, and allowing built packages to be shared among users.
1151 When @command{guix-daemon} runs as @code{root}, you may not want package
1152 build processes themselves to run as @code{root} too, for obvious
1153 security reasons. To avoid that, a special pool of @dfn{build users}
1154 should be created for use by build processes started by the daemon.
1155 These build users need not have a shell and a home directory: they will
1156 just be used when the daemon drops @code{root} privileges in build
1157 processes. Having several such users allows the daemon to launch
1158 distinct build processes under separate UIDs, which guarantees that they
1159 do not interfere with each other---an essential feature since builds are
1160 regarded as pure functions (@pxref{Introduction}).
1162 On a GNU/Linux system, a build user pool may be created like this (using
1163 Bash syntax and the @code{shadow} commands):
1165 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
1166 @c for why `-G' is needed.
1168 # groupadd --system guixbuild
1169 # for i in $(seq -w 1 10);
1171 useradd -g guixbuild -G guixbuild \
1172 -d /var/empty -s $(which nologin) \
1173 -c "Guix build user $i" --system \
1179 The number of build users determines how many build jobs may run in
1180 parallel, as specified by the @option{--max-jobs} option
1181 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1182 @command{guix system vm} and related commands, you may need to add the
1183 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1184 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1185 (@pxref{Invoking guix system}).
1187 The @code{guix-daemon} program may then be run as @code{root} with the
1188 following command@footnote{If your machine uses the systemd init system,
1189 copying the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1190 file to @file{/etc/systemd/system} will ensure that
1191 @command{guix-daemon} is automatically started. Similarly, if your
1192 machine uses the Upstart init system, copy the
1193 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1194 file to @file{/etc/init}.}:
1197 # guix-daemon --build-users-group=guixbuild
1202 This way, the daemon starts build processes in a chroot, under one of
1203 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1204 environment contains nothing but:
1206 @c Keep this list in sync with libstore/build.cc! -----------------------
1209 a minimal @code{/dev} directory, created mostly independently from the
1210 host @code{/dev}@footnote{``Mostly'', because while the set of files
1211 that appear in the chroot's @code{/dev} is fixed, most of these files
1212 can only be created if the host has them.};
1215 the @code{/proc} directory; it only shows the processes of the container
1216 since a separate PID name space is used;
1219 @file{/etc/passwd} with an entry for the current user and an entry for
1223 @file{/etc/group} with an entry for the user's group;
1226 @file{/etc/hosts} with an entry that maps @code{localhost} to
1230 a writable @file{/tmp} directory.
1233 The chroot does not contain a @file{/home} directory, and the @env{HOME}
1234 environment variable is set to the non-existent
1235 @file{/homeless-shelter}. This helps to highlight inappropriate uses of
1236 @env{HOME} in the build scripts of packages.
1238 You can influence the directory where the daemon stores build trees
1239 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1240 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1241 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1242 This way, the value of @env{TMPDIR} does not leak inside build
1243 environments, which avoids discrepancies in cases where build processes
1244 capture the name of their build tree.
1248 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1249 environment variables for HTTP and HTTPS downloads it performs, be it
1250 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1251 (@pxref{Substitutes}).
1253 If you are installing Guix as an unprivileged user, it is still possible
1254 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1255 However, build processes will not be isolated from one another, and not
1256 from the rest of the system. Thus, build processes may interfere with
1257 each other, and may access programs, libraries, and other files
1258 available on the system---making it much harder to view them as
1259 @emph{pure} functions.
1262 @node Daemon Offload Setup
1263 @subsection Using the Offload Facility
1267 When desired, the build daemon can @dfn{offload} derivation builds to
1268 other machines running Guix, using the @code{offload} @dfn{build
1269 hook}@footnote{This feature is available only when
1270 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1271 present.}. When that feature is enabled, a list of user-specified build
1272 machines is read from @file{/etc/guix/machines.scm}; every time a build
1273 is requested, for instance via @code{guix build}, the daemon attempts to
1274 offload it to one of the machines that satisfy the constraints of the
1275 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1276 A single machine can have multiple system types, either because its
1277 architecture natively supports it, via emulation
1278 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1279 or both. Missing prerequisites for the build are
1280 copied over SSH to the target machine, which then proceeds with the
1281 build; upon success the output(s) of the build are copied back to the
1282 initial machine. The offload facility comes with a basic scheduler that
1283 attempts to select the best machine. The best machine is chosen among
1284 the available machines based on criteria such as:
1288 The availability of a build slot. A build machine can have as many
1289 build slots (connections) as the value of the @code{parallel-builds}
1290 field of its @code{build-machine} object.
1293 Its relative speed, as defined via the @code{speed} field of its
1294 @code{build-machine} object.
1297 Its load. The normalized machine load must be lower than a threshold
1298 value, configurable via the @code{overload-threshold} field of its
1299 @code{build-machine} object.
1302 Disk space availability. More than a 100 MiB must be available.
1305 The @file{/etc/guix/machines.scm} file typically looks like this:
1308 (list (build-machine
1309 (name "eightysix.example.org")
1310 (systems (list "x86_64-linux" "i686-linux"))
1311 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1313 (speed 2.)) ;incredibly fast!
1316 (name "armeight.example.org")
1317 (systems (list "aarch64-linux"))
1318 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1321 ;; Remember 'guix offload' is spawned by
1322 ;; 'guix-daemon' as root.
1323 (private-key "/root/.ssh/identity-for-guix")))
1327 In the example above we specify a list of two build machines, one for
1328 the @code{x86_64} and @code{i686} architectures and one for the
1329 @code{aarch64} architecture.
1331 In fact, this file is---not surprisingly!---a Scheme file that is
1332 evaluated when the @code{offload} hook is started. Its return value
1333 must be a list of @code{build-machine} objects. While this example
1334 shows a fixed list of build machines, one could imagine, say, using
1335 DNS-SD to return a list of potential build machines discovered in the
1336 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1337 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1340 @deftp {Data Type} build-machine
1341 This data type represents build machines to which the daemon may offload
1342 builds. The important fields are:
1347 The host name of the remote machine.
1350 The system types the remote machine supports---e.g., @code{(list
1351 "x86_64-linux" "i686-linux")}.
1354 The user account to use when connecting to the remote machine over SSH.
1355 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1356 allow non-interactive logins.
1359 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1360 This is used to authenticate the machine when we connect to it. It is a
1361 long string that looks like this:
1364 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1367 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1368 key can be found in a file such as
1369 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1371 If the machine is running the SSH daemon of GNU@tie{}lsh,
1372 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1373 similar file. It can be converted to the OpenSSH format using
1374 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1377 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1378 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1383 A number of optional fields may be specified:
1387 @item @code{port} (default: @code{22})
1388 Port number of SSH server on the machine.
1390 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1391 The SSH private key file to use when connecting to the machine, in
1392 OpenSSH format. This key must not be protected with a passphrase.
1394 Note that the default value is the private key @emph{of the root
1395 account}. Make sure it exists if you use the default.
1397 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1398 @itemx @code{compression-level} (default: @code{3})
1399 The SSH-level compression methods and compression level requested.
1401 Note that offloading relies on SSH compression to reduce bandwidth usage
1402 when transferring files to and from build machines.
1404 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1405 File name of the Unix-domain socket @command{guix-daemon} is listening
1408 @item @code{overload-threshold} (default: @code{0.6})
1409 The load threshold above which a potential offload machine is
1410 disregarded by the offload scheduler. The value roughly translates to
1411 the total processor usage of the build machine, ranging from 0.0 (0%) to
1412 1.0 (100%). It can also be disabled by setting
1413 @code{overload-threshold} to @code{#f}.
1415 @item @code{parallel-builds} (default: @code{1})
1416 The number of builds that may run in parallel on the machine.
1418 @item @code{speed} (default: @code{1.0})
1419 A ``relative speed factor''. The offload scheduler will tend to prefer
1420 machines with a higher speed factor.
1422 @item @code{features} (default: @code{'()})
1423 A list of strings denoting specific features supported by the machine.
1424 An example is @code{"kvm"} for machines that have the KVM Linux modules
1425 and corresponding hardware support. Derivations can request features by
1426 name, and they will be scheduled on matching build machines.
1431 The @command{guix} command must be in the search path on the build
1432 machines. You can check whether this is the case by running:
1435 ssh build-machine guix repl --version
1438 There is one last thing to do once @file{machines.scm} is in place. As
1439 explained above, when offloading, files are transferred back and forth
1440 between the machine stores. For this to work, you first need to
1441 generate a key pair on each machine to allow the daemon to export signed
1442 archives of files from the store (@pxref{Invoking guix archive}):
1445 # guix archive --generate-key
1449 Each build machine must authorize the key of the master machine so that
1450 it accepts store items it receives from the master:
1453 # guix archive --authorize < master-public-key.txt
1457 Likewise, the master machine must authorize the key of each build machine.
1459 All the fuss with keys is here to express pairwise mutual trust
1460 relations between the master and the build machines. Concretely, when
1461 the master receives files from a build machine (and @i{vice versa}), its
1462 build daemon can make sure they are genuine, have not been tampered
1463 with, and that they are signed by an authorized key.
1465 @cindex offload test
1466 To test whether your setup is operational, run this command on the
1473 This will attempt to connect to each of the build machines specified in
1474 @file{/etc/guix/machines.scm}, make sure Guix is
1475 available on each machine, attempt to export to the machine and import
1476 from it, and report any error in the process.
1478 If you want to test a different machine file, just specify it on the
1482 # guix offload test machines-qualif.scm
1485 Last, you can test the subset of the machines whose name matches a
1486 regular expression like this:
1489 # guix offload test machines.scm '\.gnu\.org$'
1492 @cindex offload status
1493 To display the current load of all build hosts, run this command on the
1497 # guix offload status
1501 @node SELinux Support
1502 @subsection SELinux Support
1504 @cindex SELinux, daemon policy
1505 @cindex mandatory access control, SELinux
1506 @cindex security, guix-daemon
1507 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1508 can be installed on a system where SELinux is enabled, in order to label
1509 Guix files and to specify the expected behavior of the daemon. Since
1510 Guix System does not provide an SELinux base policy, the daemon policy cannot
1511 be used on Guix System.
1513 @subsubsection Installing the SELinux policy
1514 @cindex SELinux, policy installation
1515 To install the policy run this command as root:
1518 semodule -i etc/guix-daemon.cil
1521 Then relabel the file system with @code{restorecon} or by a different
1522 mechanism provided by your system.
1524 Once the policy is installed, the file system has been relabeled, and
1525 the daemon has been restarted, it should be running in the
1526 @code{guix_daemon_t} context. You can confirm this with the following
1530 ps -Zax | grep guix-daemon
1533 Monitor the SELinux log files as you run a command like @code{guix build
1534 hello} to convince yourself that SELinux permits all necessary
1537 @subsubsection Limitations
1538 @cindex SELinux, limitations
1540 This policy is not perfect. Here is a list of limitations or quirks
1541 that should be considered when deploying the provided SELinux policy for
1546 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1547 operations involve contexts that have anything to do with
1548 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1549 but it would be preferable to define socket rules for only this label.
1552 @code{guix gc} cannot access arbitrary links to profiles. By design,
1553 the file label of the destination of a symlink is independent of the
1554 file label of the link itself. Although all profiles under
1555 $localstatedir are labelled, the links to these profiles inherit the
1556 label of the directory they are in. For links in the user’s home
1557 directory this will be @code{user_home_t}. But for links from the root
1558 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1559 directory, etc, this won’t work. @code{guix gc} would be prevented from
1560 reading and following these links.
1563 The daemon’s feature to listen for TCP connections might no longer work.
1564 This might require extra rules, because SELinux treats network sockets
1565 differently from files.
1568 Currently all files with a name matching the regular expression
1569 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1570 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1571 that name in any profile would be permitted to run in the
1572 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1573 build a package that provides this executable and convince a user to
1574 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1575 At that point SELinux could not prevent it from accessing files that are
1576 allowed for processes in that domain.
1578 You will need to relabel the store directory after all upgrades to
1579 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1580 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1581 or by other means provided by your operating system.
1583 We could generate a much more restrictive policy at installation time,
1584 so that only the @emph{exact} file name of the currently installed
1585 @code{guix-daemon} executable would be labelled with
1586 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1587 The downside is that root would have to install or upgrade the policy at
1588 installation time whenever the Guix package that provides the
1589 effectively running @code{guix-daemon} executable is upgraded.
1592 @node Invoking guix-daemon
1593 @section Invoking @command{guix-daemon}
1594 @cindex @command{guix-daemon}
1595 The @command{guix-daemon} program implements all the functionality to
1596 access the store. This includes launching build processes, running the
1597 garbage collector, querying the availability of a build result, etc. It
1598 is normally run as @code{root} like this:
1601 # guix-daemon --build-users-group=guixbuild
1604 @cindex socket activation, for @command{guix-daemon}
1605 This daemon can also be started following the systemd ``socket
1606 activation'' protocol (@pxref{Service De- and Constructors,
1607 @code{make-systemd-constructor},, shepherd, The GNU Shepherd Manual}).
1609 For details on how to set it up, @pxref{Setting Up the Daemon}.
1612 @cindex container, build environment
1613 @cindex build environment
1614 @cindex reproducible builds
1615 By default, @command{guix-daemon} launches build processes under
1616 different UIDs, taken from the build group specified with
1617 @option{--build-users-group}. In addition, each build process is run in a
1618 chroot environment that only contains the subset of the store that the
1619 build process depends on, as specified by its derivation
1620 (@pxref{Programming Interface, derivation}), plus a set of specific
1621 system directories. By default, the latter contains @file{/dev} and
1622 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1623 @dfn{container}: in addition to having its own file system tree, it has
1624 a separate mount name space, its own PID name space, network name space,
1625 etc. This helps achieve reproducible builds (@pxref{Features}).
1627 When the daemon performs a build on behalf of the user, it creates a
1628 build directory under @file{/tmp} or under the directory specified by
1629 its @env{TMPDIR} environment variable. This directory is shared with
1630 the container for the duration of the build, though within the container,
1631 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1633 The build directory is automatically deleted upon completion, unless the
1634 build failed and the client specified @option{--keep-failed}
1635 (@pxref{Common Build Options, @option{--keep-failed}}).
1637 The daemon listens for connections and spawns one sub-process for each session
1638 started by a client (one of the @command{guix} sub-commands). The
1639 @command{guix processes} command allows you to get an overview of the activity
1640 on your system by viewing each of the active sessions and clients.
1641 @xref{Invoking guix processes}, for more information.
1643 The following command-line options are supported:
1646 @item --build-users-group=@var{group}
1647 Take users from @var{group} to run build processes (@pxref{Setting Up
1648 the Daemon, build users}).
1650 @item --no-substitutes
1652 Do not use substitutes for build products. That is, always build things
1653 locally instead of allowing downloads of pre-built binaries
1654 (@pxref{Substitutes}).
1656 When the daemon runs with @option{--no-substitutes}, clients can still
1657 explicitly enable substitution @i{via} the @code{set-build-options}
1658 remote procedure call (@pxref{The Store}).
1660 @anchor{daemon-substitute-urls}
1661 @item --substitute-urls=@var{urls}
1662 Consider @var{urls} the default whitespace-separated list of substitute
1663 source URLs. When this option is omitted,
1664 @indicateurl{@value{SUBSTITUTE-URLS}} is used.
1666 This means that substitutes may be downloaded from @var{urls}, as long
1667 as they are signed by a trusted signature (@pxref{Substitutes}).
1669 @xref{Getting Substitutes from Other Servers}, for more information on
1670 how to configure the daemon to get substitutes from other servers.
1674 Do not use offload builds to other machines (@pxref{Daemon Offload
1675 Setup}). That is, always build things locally instead of offloading
1676 builds to remote machines.
1678 @item --cache-failures
1679 Cache build failures. By default, only successful builds are cached.
1681 When this option is used, @command{guix gc --list-failures} can be used
1682 to query the set of store items marked as failed; @command{guix gc
1683 --clear-failures} removes store items from the set of cached failures.
1684 @xref{Invoking guix gc}.
1686 @item --cores=@var{n}
1688 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1691 The default value is @code{0}, but it may be overridden by clients, such
1692 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1695 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1696 in the build process, which can then use it to exploit internal
1697 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1699 @item --max-jobs=@var{n}
1701 Allow at most @var{n} build jobs in parallel. The default value is
1702 @code{1}. Setting it to @code{0} means that no builds will be performed
1703 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1704 Setup}), or simply fail.
1706 @item --max-silent-time=@var{seconds}
1707 When the build or substitution process remains silent for more than
1708 @var{seconds}, terminate it and report a build failure.
1710 The default value is @code{0}, which disables the timeout.
1712 The value specified here can be overridden by clients (@pxref{Common
1713 Build Options, @option{--max-silent-time}}).
1715 @item --timeout=@var{seconds}
1716 Likewise, when the build or substitution process lasts for more than
1717 @var{seconds}, terminate it and report a build failure.
1719 The default value is @code{0}, which disables the timeout.
1721 The value specified here can be overridden by clients (@pxref{Common
1722 Build Options, @option{--timeout}}).
1724 @item --rounds=@var{N}
1725 Build each derivation @var{n} times in a row, and raise an error if
1726 consecutive build results are not bit-for-bit identical. Note that this
1727 setting can be overridden by clients such as @command{guix build}
1728 (@pxref{Invoking guix build}).
1730 When used in conjunction with @option{--keep-failed}, the differing
1731 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1732 This makes it easy to look for differences between the two results.
1735 Produce debugging output.
1737 This is useful to debug daemon start-up issues, but then it may be
1738 overridden by clients, for example the @option{--verbosity} option of
1739 @command{guix build} (@pxref{Invoking guix build}).
1741 @item --chroot-directory=@var{dir}
1742 Add @var{dir} to the build chroot.
1744 Doing this may change the result of build processes---for instance if
1745 they use optional dependencies found in @var{dir} when it is available,
1746 and not otherwise. For that reason, it is not recommended to do so.
1747 Instead, make sure that each derivation declares all the inputs that it
1750 @item --disable-chroot
1751 Disable chroot builds.
1753 Using this option is not recommended since, again, it would allow build
1754 processes to gain access to undeclared dependencies. It is necessary,
1755 though, when @command{guix-daemon} is running under an unprivileged user
1758 @item --log-compression=@var{type}
1759 Compress build logs according to @var{type}, one of @code{gzip},
1760 @code{bzip2}, or @code{none}.
1762 Unless @option{--lose-logs} is used, all the build logs are kept in the
1763 @var{localstatedir}. To save space, the daemon automatically compresses
1764 them with gzip by default.
1766 @item --discover[=yes|no]
1767 Whether to discover substitute servers on the local network using mDNS
1770 This feature is still experimental. However, here are a few
1775 It might be faster/less expensive than fetching from remote servers;
1777 There are no security risks, only genuine substitutes will be used
1778 (@pxref{Substitute Authentication});
1780 An attacker advertising @command{guix publish} on your LAN cannot serve
1781 you malicious binaries, but they can learn what software you’re
1784 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1785 LAN can see what software you’re installing.
1788 It is also possible to enable or disable substitute server discovery at
1789 run-time by running:
1792 herd discover guix-daemon on
1793 herd discover guix-daemon off
1796 @item --disable-deduplication
1797 @cindex deduplication
1798 Disable automatic file ``deduplication'' in the store.
1800 By default, files added to the store are automatically ``deduplicated'':
1801 if a newly added file is identical to another one found in the store,
1802 the daemon makes the new file a hard link to the other file. This can
1803 noticeably reduce disk usage, at the expense of slightly increased
1804 input/output load at the end of a build process. This option disables
1807 @item --gc-keep-outputs[=yes|no]
1808 Tell whether the garbage collector (GC) must keep outputs of live
1812 @cindex garbage collector roots
1813 When set to @code{yes}, the GC will keep the outputs of any live
1814 derivation available in the store---the @file{.drv} files. The default
1815 is @code{no}, meaning that derivation outputs are kept only if they are
1816 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1819 @item --gc-keep-derivations[=yes|no]
1820 Tell whether the garbage collector (GC) must keep derivations
1821 corresponding to live outputs.
1823 When set to @code{yes}, as is the case by default, the GC keeps
1824 derivations---i.e., @file{.drv} files---as long as at least one of their
1825 outputs is live. This allows users to keep track of the origins of
1826 items in their store. Setting it to @code{no} saves a bit of disk
1829 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1830 liveness to flow from outputs to derivations, and setting
1831 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1832 derivations to outputs. When both are set to @code{yes}, the effect is
1833 to keep all the build prerequisites (the sources, compiler, libraries,
1834 and other build-time tools) of live objects in the store, regardless of
1835 whether these prerequisites are reachable from a GC root. This is
1836 convenient for developers since it saves rebuilds or downloads.
1838 @item --impersonate-linux-2.6
1839 On Linux-based systems, impersonate Linux 2.6. This means that the
1840 kernel's @command{uname} system call will report 2.6 as the release number.
1842 This might be helpful to build programs that (usually wrongfully) depend
1843 on the kernel version number.
1846 Do not keep build logs. By default they are kept under
1847 @file{@var{localstatedir}/guix/log}.
1849 @item --system=@var{system}
1850 Assume @var{system} as the current system type. By default it is the
1851 architecture/kernel pair found at configure time, such as
1852 @code{x86_64-linux}.
1854 @item --listen=@var{endpoint}
1855 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1856 as the file name of a Unix-domain socket if it starts with
1857 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1858 host name or host name and port to listen to. Here are a few examples:
1861 @item --listen=/gnu/var/daemon
1862 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1863 creating it if needed.
1865 @item --listen=localhost
1866 @cindex daemon, remote access
1867 @cindex remote access to the daemon
1868 @cindex daemon, cluster setup
1869 @cindex clusters, daemon setup
1870 Listen for TCP connections on the network interface corresponding to
1871 @code{localhost}, on port 44146.
1873 @item --listen=128.0.0.42:1234
1874 Listen for TCP connections on the network interface corresponding to
1875 @code{128.0.0.42}, on port 1234.
1878 This option can be repeated multiple times, in which case
1879 @command{guix-daemon} accepts connections on all the specified
1880 endpoints. Users can tell client commands what endpoint to connect to
1881 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1882 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1885 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1886 @option{--listen=@var{host}} is suitable on local networks, such as
1887 clusters, where only trusted nodes may connect to the build daemon. In
1888 other cases where remote access to the daemon is needed, we recommend
1889 using Unix-domain sockets along with SSH.
1892 When @option{--listen} is omitted, @command{guix-daemon} listens for
1893 connections on the Unix-domain socket located at
1894 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1898 @node Application Setup
1899 @section Application Setup
1901 @cindex foreign distro
1902 When using Guix on top of GNU/Linux distribution other than Guix System---a
1903 so-called @dfn{foreign distro}---a few additional steps are needed to
1904 get everything in place. Here are some of them.
1908 @anchor{locales-and-locpath}
1909 @cindex locales, when not on Guix System
1911 @vindex GUIX_LOCPATH
1912 Packages installed @i{via} Guix will not use the locale data of the
1913 host system. Instead, you must first install one of the locale packages
1914 available with Guix and then define the @env{GUIX_LOCPATH} environment
1918 $ guix install glibc-locales
1919 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1922 Note that the @code{glibc-locales} package contains data for all the
1923 locales supported by the GNU@tie{}libc and weighs in at around
1924 930@tie{}MiB@footnote{The size of the @code{glibc-locales} package is
1925 reduced down to about 213@tie{}MiB with store deduplication and further
1926 down to about 67@tie{}MiB when using a zstd-compressed Btrfs file
1927 system.}. If you only need a few locales, you can define your custom
1928 locales package via the @code{make-glibc-utf8-locales} procedure from
1929 the @code{(gnu packages base)} module. The following example defines a
1930 package containing the various Canadian UTF-8 locales known to the
1931 GNU@tie{}libc, that weighs around 14@tie{}MiB:
1934 (use-modules (gnu packages base))
1936 (define my-glibc-locales
1937 (make-glibc-utf8-locales
1939 #:locales (list "en_CA" "fr_CA" "ik_CA" "iu_CA" "shs_CA")
1940 #:name "glibc-canadian-utf8-locales"))
1943 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1944 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1945 Manual}). There are two important differences though:
1949 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1950 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1951 to make sure the programs of the foreign distro will not end up loading
1952 incompatible locale data.
1955 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1956 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1957 should your Guix profile contain a mixture of programs linked against
1958 different libc version, each libc version will only try to load locale
1959 data in the right format.
1962 This is important because the locale data format used by different libc
1963 versions may be incompatible.
1965 @subsection Name Service Switch
1967 @cindex name service switch, glibc
1968 @cindex NSS (name service switch), glibc
1969 @cindex nscd (name service caching daemon)
1970 @cindex name service caching daemon (nscd)
1971 When using Guix on a foreign distro, we @emph{strongly recommend} that
1972 the system run the GNU C library's @dfn{name service cache daemon},
1973 @command{nscd}, which should be listening on the
1974 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1975 installed with Guix may fail to look up host names or user accounts, or
1976 may even crash. The next paragraphs explain why.
1978 @cindex @file{nsswitch.conf}
1979 The GNU C library implements a @dfn{name service switch} (NSS), which is
1980 an extensible mechanism for ``name lookups'' in general: host name
1981 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1982 The GNU C Library Reference Manual}).
1984 @cindex Network information service (NIS)
1985 @cindex NIS (Network information service)
1986 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1987 lookup implementations: for example, the @code{nss-mdns} plugin allow
1988 resolution of @code{.local} host names, the @code{nis} plugin allows
1989 user account lookup using the Network information service (NIS), and so
1990 on. These extra ``lookup services'' are configured system-wide in
1991 @file{/etc/nsswitch.conf}, and all the programs running on the system
1992 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1995 When they perform a name lookup---for instance by calling the
1996 @code{getaddrinfo} function in C---applications first try to connect to
1997 the nscd; on success, nscd performs name lookups on their behalf. If
1998 the nscd is not running, then they perform the name lookup by
1999 themselves, by loading the name lookup services into their own address
2000 space and running it. These name lookup services---the
2001 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
2002 the host system's C library, rather than from the C library the
2003 application is linked against (the C library coming from Guix).
2005 And this is where the problem is: if your application is linked against
2006 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
2007 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
2008 likely crash or have its name lookups fail unexpectedly.
2010 Running @command{nscd} on the system, among other advantages, eliminates
2011 this binary incompatibility problem because those @code{libnss_*.so}
2012 files are loaded in the @command{nscd} process, not in applications
2015 @subsection X11 Fonts
2018 The majority of graphical applications use Fontconfig to locate and load
2019 fonts and perform X11-client-side rendering. The @code{fontconfig}
2020 package in Guix looks for fonts in @file{$HOME/.guix-profile} by
2021 default. Thus, to allow graphical applications installed with Guix to
2022 display fonts, you have to install fonts with Guix as well. Essential
2023 font packages include @code{font-ghostscript}, @code{font-dejavu}, and
2024 @code{font-gnu-freefont}.
2026 @cindex @code{fc-cache}
2028 Once you have installed or removed fonts, or when you notice an
2029 application that does not find fonts, you may need to install Fontconfig
2030 and to force an update of its font cache by running:
2033 guix install fontconfig
2037 To display text written in Chinese languages, Japanese, or Korean in
2038 graphical applications, consider installing
2039 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
2040 has multiple outputs, one per language family (@pxref{Packages with
2041 Multiple Outputs}). For instance, the following command installs fonts
2042 for Chinese languages:
2045 guix install font-adobe-source-han-sans:cn
2048 @cindex @code{xterm}
2049 Older programs such as @command{xterm} do not use Fontconfig and instead
2050 rely on server-side font rendering. Such programs require to specify a
2051 full name of a font using XLFD (X Logical Font Description), like this:
2054 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
2057 To be able to use such full names for the TrueType fonts installed in
2058 your Guix profile, you need to extend the font path of the X server:
2060 @c Note: 'xset' does not accept symlinks so the trick below arranges to
2061 @c get at the real directory. See <https://bugs.gnu.org/30655>.
2063 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
2066 @cindex @code{xlsfonts}
2067 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
2068 to make sure your TrueType fonts are listed there.
2071 @subsection X.509 Certificates
2073 @cindex @code{nss-certs}
2074 The @code{nss-certs} package provides X.509 certificates, which allow
2075 programs to authenticate Web servers accessed over HTTPS.
2077 When using Guix on a foreign distro, you can install this package and
2078 define the relevant environment variables so that packages know where to
2079 look for certificates. @xref{X.509 Certificates}, for detailed
2082 @subsection Emacs Packages
2084 @cindex @code{emacs}
2085 When you install Emacs packages with Guix, the Elisp files are placed
2086 under the @file{share/emacs/site-lisp/} directory of the profile in
2087 which they are installed. The Elisp libraries are made available to
2088 Emacs through the @env{EMACSLOADPATH} environment variable, which is
2089 set when installing Emacs itself.
2091 Additionally, autoload definitions are automatically evaluated at the
2092 initialization of Emacs, by the Guix-specific
2093 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
2094 want to avoid auto-loading the Emacs packages installed with Guix, you
2095 can do so by running Emacs with the @option{--no-site-file} option
2096 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
2099 @node Upgrading Guix
2100 @section Upgrading Guix
2102 @cindex Upgrading Guix, on a foreign distro
2104 To upgrade Guix, run:
2110 @xref{Invoking guix pull}, for more information.
2112 @cindex upgrading Guix for the root user, on a foreign distro
2113 @cindex upgrading the Guix daemon, on a foreign distro
2114 @cindex @command{guix pull} for the root user, on a foreign distro
2116 On a foreign distro, you can upgrade the build daemon by running:
2123 followed by (assuming your distro uses the systemd service management
2127 systemctl restart guix-daemon.service
2130 On Guix System, upgrading the daemon is achieved by reconfiguring the
2131 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
2135 @c *********************************************************************
2136 @node System Installation
2137 @chapter System Installation
2139 @cindex installing Guix System
2140 @cindex Guix System, installation
2141 This section explains how to install Guix System
2142 on a machine. Guix, as a package manager, can
2143 also be installed on top of a running GNU/Linux system,
2144 @pxref{Installation}.
2148 @c This paragraph is for people reading this from tty2 of the
2149 @c installation image.
2150 You are reading this documentation with an Info reader. For details on
2151 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
2152 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
2153 Info}. Hit @kbd{l} afterwards to come back here.
2155 Alternatively, run @command{info info} in another tty to keep the manual
2161 * Limitations:: What you can expect.
2162 * Hardware Considerations:: Supported hardware.
2163 * USB Stick and DVD Installation:: Preparing the installation medium.
2164 * Preparing for Installation:: Networking, partitioning, etc.
2165 * Guided Graphical Installation:: Easy graphical installation.
2166 * Manual Installation:: Manual installation for wizards.
2167 * After System Installation:: When installation succeeded.
2168 * Installing Guix in a VM:: Guix System playground.
2169 * Building the Installation Image:: How this comes to be.
2173 @section Limitations
2175 We consider Guix System to be ready for a wide range of ``desktop'' and server
2176 use cases. The reliability guarantees it provides---transactional upgrades
2177 and rollbacks, reproducibility---make it a solid foundation.
2179 Nevertheless, before you proceed with the installation, be aware of the
2180 following noteworthy limitations applicable to version @value{VERSION}:
2184 More and more system services are provided (@pxref{Services}), but some
2188 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
2189 as well as a number of X11 window managers. However, KDE is currently
2193 More than a disclaimer, this is an invitation to report issues (and success
2194 stories!), and to join us in improving it. @xref{Contributing}, for more
2198 @node Hardware Considerations
2199 @section Hardware Considerations
2201 @cindex hardware support on Guix System
2202 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2203 builds around the kernel Linux-libre, which means that only hardware for
2204 which free software drivers and firmware exist is supported. Nowadays,
2205 a wide range of off-the-shelf hardware is supported on
2206 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2207 Ethernet controllers. Unfortunately, there are still areas where
2208 hardware vendors deny users control over their own computing, and such
2209 hardware is not supported on Guix System.
2211 @cindex WiFi, hardware support
2212 One of the main areas where free drivers or firmware are lacking is WiFi
2213 devices. WiFi devices known to work include those using Atheros chips
2214 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2215 driver, and those using Broadcom/AirForce chips (BCM43xx with
2216 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2217 Linux-libre driver. Free firmware exists for both and is available
2218 out-of-the-box on Guix System, as part of @code{%base-firmware}
2219 (@pxref{operating-system Reference, @code{firmware}}).
2221 @cindex RYF, Respects Your Freedom
2222 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2223 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2224 certification program for hardware products that respect your freedom
2225 and your privacy and ensure that you have control over your device. We
2226 encourage you to check the list of RYF-certified devices.
2228 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2229 web site. It contains a catalog of hardware devices with information
2230 about their support in GNU/Linux.
2233 @node USB Stick and DVD Installation
2234 @section USB Stick and DVD Installation
2236 An ISO-9660 installation image that can be written to a USB stick or
2237 burnt to a DVD can be downloaded from
2238 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso},
2239 where you can replace @code{x86_64-linux} with one of:
2243 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2246 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2249 @c start duplication of authentication part from ``Binary Installation''
2250 Make sure to download the associated @file{.sig} file and to verify the
2251 authenticity of the image against it, along these lines:
2254 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.sig
2255 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.sig
2258 If that command fails because you do not have the required public key,
2259 then run this command to import it:
2262 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2263 -qO - | gpg --import -
2267 and rerun the @code{gpg --verify} command.
2269 Take note that a warning like ``This key is not certified with a trusted
2270 signature!'' is normal.
2274 This image contains the tools necessary for an installation.
2275 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2277 @unnumberedsubsec Copying to a USB Stick
2279 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2280 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2281 copy the image with:
2284 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2288 Access to @file{/dev/sdX} usually requires root privileges.
2290 @unnumberedsubsec Burning on a DVD
2292 Insert a blank DVD into your machine, and determine
2293 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2294 copy the image with:
2297 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2300 Access to @file{/dev/srX} usually requires root privileges.
2302 @unnumberedsubsec Booting
2304 Once this is done, you should be able to reboot the system and boot from
2305 the USB stick or DVD@. The latter usually requires you to get in the
2306 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2307 In order to boot from Libreboot, switch to the command mode by pressing
2308 the @kbd{c} key and type @command{search_grub usb}.
2310 @xref{Installing Guix in a VM}, if, instead, you would like to install
2311 Guix System in a virtual machine (VM).
2314 @node Preparing for Installation
2315 @section Preparing for Installation
2317 Once you have booted, you can use the guided graphical installer, which makes
2318 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2319 if you are already familiar with GNU/Linux and if you want more control than
2320 what the graphical installer provides, you can choose the ``manual''
2321 installation process (@pxref{Manual Installation}).
2323 The graphical installer is available on TTY1. You can obtain root shells on
2324 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2325 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2326 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2327 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2328 which allows you to select text with the left mouse button and to paste it
2329 with the middle button.
2332 Installation requires access to the Internet so that any missing
2333 dependencies of your system configuration can be downloaded. See the
2334 ``Networking'' section below.
2337 @node Guided Graphical Installation
2338 @section Guided Graphical Installation
2340 The graphical installer is a text-based user interface. It will guide you,
2341 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2343 The first dialog boxes allow you to set up the system as you use it during the
2344 installation: you can choose the language, keyboard layout, and set up
2345 networking, which will be used during the installation. The image below shows
2346 the networking dialog.
2348 @image{images/installer-network,5in,, networking setup with the graphical installer}
2350 Later steps allow you to partition your hard disk, as shown in the image
2351 below, to choose whether or not to use encrypted file systems, to enter the
2352 host name and root password, and to create an additional account, among other
2355 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2357 Note that, at any time, the installer allows you to exit the current
2358 installation step and resume at a previous step, as show in the image below.
2360 @image{images/installer-resume,5in,, resuming the installation process}
2362 Once you're done, the installer produces an operating system configuration and
2363 displays it (@pxref{Using the Configuration System}). At that point you can
2364 hit ``OK'' and installation will proceed. On success, you can reboot into the
2365 new system and enjoy. @xref{After System Installation}, for what's next!
2368 @node Manual Installation
2369 @section Manual Installation
2371 This section describes how you would ``manually'' install GNU@tie{}Guix System
2372 on your machine. This option requires familiarity with GNU/Linux, with the
2373 shell, and with common administration tools. If you think this is not for
2374 you, consider using the guided graphical installer (@pxref{Guided Graphical
2377 The installation system provides root shells on TTYs 3 to 6; press
2378 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2379 many common tools needed to install the system, but is also a full-blown
2380 Guix System. This means that you can install additional packages, should you
2381 need it, using @command{guix package} (@pxref{Invoking guix package}).
2384 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2385 * Proceeding with the Installation:: Installing.
2388 @node Keyboard Layout and Networking and Partitioning
2389 @subsection Keyboard Layout, Networking, and Partitioning
2391 Before you can install the system, you may want to adjust the keyboard layout,
2392 set up networking, and partition your target hard disk. This section will
2393 guide you through this.
2395 @subsubsection Keyboard Layout
2397 @cindex keyboard layout
2398 The installation image uses the US qwerty keyboard layout. If you want
2399 to change it, you can use the @command{loadkeys} command. For example,
2400 the following command selects the Dvorak keyboard layout:
2406 See the files under @file{/run/current-system/profile/share/keymaps} for
2407 a list of available keyboard layouts. Run @command{man loadkeys} for
2410 @anchor{manual-installation-networking}
2411 @subsubsection Networking
2413 Run the following command to see what your network interfaces are called:
2420 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2426 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2427 Wired interfaces have a name starting with @samp{e}; for example, the
2428 interface corresponding to the first on-board Ethernet controller is
2429 called @samp{eno1}. Wireless interfaces have a name starting with
2430 @samp{w}, like @samp{w1p2s0}.
2433 @item Wired connection
2434 To configure a wired network run the following command, substituting
2435 @var{interface} with the name of the wired interface you want to use.
2438 ifconfig @var{interface} up
2442 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2445 ip link set @var{interface} up
2448 @item Wireless connection
2451 To configure wireless networking, you can create a configuration file
2452 for the @command{wpa_supplicant} configuration tool (its location is not
2453 important) using one of the available text editors such as
2457 nano wpa_supplicant.conf
2460 As an example, the following stanza can go to this file and will work
2461 for many wireless networks, provided you give the actual SSID and
2462 passphrase for the network you are connecting to:
2466 ssid="@var{my-ssid}"
2468 psk="the network's secret passphrase"
2472 Start the wireless service and run it in the background with the
2473 following command (substitute @var{interface} with the name of the
2474 network interface you want to use):
2477 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2480 Run @command{man wpa_supplicant} for more information.
2484 At this point, you need to acquire an IP address. On a network where IP
2485 addresses are automatically assigned @i{via} DHCP, you can run:
2488 dhclient -v @var{interface}
2491 Try to ping a server to see if networking is up and running:
2497 Setting up network access is almost always a requirement because the
2498 image does not contain all the software and tools that may be needed.
2500 @cindex proxy, during system installation
2501 If you need HTTP and HTTPS access to go through a proxy, run the
2505 herd set-http-proxy guix-daemon @var{URL}
2509 where @var{URL} is the proxy URL, for example
2510 @code{http://example.org:8118}.
2512 @cindex installing over SSH
2513 If you want to, you can continue the installation remotely by starting
2517 herd start ssh-daemon
2520 Make sure to either set a password with @command{passwd}, or configure
2521 OpenSSH public key authentication before logging in.
2523 @subsubsection Disk Partitioning
2525 Unless this has already been done, the next step is to partition, and
2526 then format the target partition(s).
2528 The installation image includes several partitioning tools, including
2529 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2530 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2531 the partition layout you want:
2537 If your disk uses the GUID Partition Table (GPT) format and you plan to
2538 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2539 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2542 @cindex EFI, installation
2543 @cindex UEFI, installation
2544 @cindex ESP, EFI system partition
2545 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2546 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2547 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2550 parted /dev/sda set 1 esp on
2554 @vindex grub-bootloader
2555 @vindex grub-efi-bootloader
2556 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2557 @file{/sys/firmware/efi} exists in the installation image, then you should
2558 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2559 Otherwise you should use the BIOS-based GRUB, known as
2560 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2564 Once you are done partitioning the target hard disk drive, you have to
2565 create a file system on the relevant partition(s)@footnote{Currently
2566 Guix System only supports ext4, btrfs, JFS, F2FS, and XFS file systems. In
2567 particular, code that reads file system UUIDs and labels only works for these
2568 file system types.}. For the ESP, if you have one and assuming it is
2569 @file{/dev/sda1}, run:
2572 mkfs.fat -F32 /dev/sda1
2575 For the root file system, ext4 is the most widely used format. Other
2576 file systems, such as Btrfs, support compression, which is reported to
2577 nicely complement file deduplication that the daemon performs
2578 independently of the file system (@pxref{Invoking guix-daemon,
2581 Preferably, assign file systems a label so that you can easily and
2582 reliably refer to them in @code{file-system} declarations (@pxref{File
2583 Systems}). This is typically done using the @code{-L} option of
2584 @command{mkfs.ext4} and related commands. So, assuming the target root
2585 partition lives at @file{/dev/sda2}, a file system with the label
2586 @code{my-root} can be created with:
2589 mkfs.ext4 -L my-root /dev/sda2
2592 @cindex encrypted disk
2593 If you are instead planning to encrypt the root partition, you can use
2594 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2595 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2596 @code{man cryptsetup}} for more information).
2599 Note that GRUB can unlock LUKS2 devices since version 2.06, but only
2600 supports the PBKDF2 key derivation function, which is not the default
2601 for @command{cryptsetup luksFormat}. You can check which key derivation
2602 function is being used by a device by running @command{cryptsetup
2603 luksDump @var{device}}, and looking for the PBKDF field of your
2607 Assuming you want to store the root partition on @file{/dev/sda2}, the
2608 command sequence to format it as a LUKS2 partition would be along these
2612 cryptsetup luksFormat --type luks2 --pbkdf pbkdf2 /dev/sda2
2613 cryptsetup open /dev/sda2 my-partition
2614 mkfs.ext4 -L my-root /dev/mapper/my-partition
2617 Once that is done, mount the target file system under @file{/mnt}
2618 with a command like (again, assuming @code{my-root} is the label of the
2622 mount LABEL=my-root /mnt
2625 Also mount any other file systems you would like to use on the target
2626 system relative to this path. If you have opted for @file{/boot/efi} as an
2627 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2628 found by @code{guix system init} afterwards.
2630 Finally, if you plan to use one or more swap partitions (@pxref{Swap
2631 Space}), make sure to initialize them with @command{mkswap}. Assuming
2632 you have one swap partition on @file{/dev/sda3}, you would run:
2639 Alternatively, you may use a swap file. For example, assuming that in
2640 the new system you want to use the file @file{/swapfile} as a swap file,
2641 you would run@footnote{This example will work for many types of file
2642 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2643 btrfs), the required steps may be different. For details, see the
2644 manual pages for @command{mkswap} and @command{swapon}.}:
2647 # This is 10 GiB of swap space. Adjust "count" to change the size.
2648 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2649 # For security, make the file readable and writable only by root.
2650 chmod 600 /mnt/swapfile
2651 mkswap /mnt/swapfile
2652 swapon /mnt/swapfile
2655 Note that if you have encrypted the root partition and created a swap
2656 file in its file system as described above, then the encryption also
2657 protects the swap file, just like any other file in that file system.
2659 @node Proceeding with the Installation
2660 @subsection Proceeding with the Installation
2662 With the target partitions ready and the target root mounted on
2663 @file{/mnt}, we're ready to go. First, run:
2666 herd start cow-store /mnt
2669 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2670 during the installation phase are written to the target disk on @file{/mnt}
2671 rather than kept in memory. This is necessary because the first phase of
2672 the @command{guix system init} command (see below) entails downloads or
2673 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2675 Next, you have to edit a file and
2676 provide the declaration of the operating system to be installed. To
2677 that end, the installation system comes with three text editors. We
2678 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2679 supports syntax highlighting and parentheses matching; other editors
2680 include mg (an Emacs clone), and
2681 nvi (a clone of the original BSD @command{vi} editor).
2682 We strongly recommend storing that file on the target root file system, say,
2683 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2684 configuration file once you have rebooted into the newly-installed system.
2686 @xref{Using the Configuration System}, for an overview of the
2687 configuration file. The example configurations discussed in that
2688 section are available under @file{/etc/configuration} in the
2689 installation image. Thus, to get started with a system configuration
2690 providing a graphical display server (a ``desktop'' system), you can run
2691 something along these lines:
2695 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2696 # nano /mnt/etc/config.scm
2699 You should pay attention to what your configuration file contains, and
2704 Make sure the @code{bootloader-configuration} form refers to the targets
2705 you want to install GRUB on. It should mention @code{grub-bootloader}
2706 if you are installing GRUB in the legacy way, or
2707 @code{grub-efi-bootloader} for newer UEFI systems. For legacy systems,
2708 the @code{targets} field contain the names of the devices, like
2709 @code{(list "/dev/sda")}; for UEFI systems it names the paths to mounted
2710 EFI partitions, like @code{(list "/boot/efi")}; do make sure the paths
2711 are currently mounted and a @code{file-system} entry is specified in
2715 Be sure that your file system labels match the value of their respective
2716 @code{device} fields in your @code{file-system} configuration, assuming
2717 your @code{file-system} configuration uses the @code{file-system-label}
2718 procedure in its @code{device} field.
2721 If there are encrypted or RAID partitions, make sure to add a
2722 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2725 Once you are done preparing the configuration file, the new system must
2726 be initialized (remember that the target root file system is mounted
2730 guix system init /mnt/etc/config.scm /mnt
2734 This copies all the necessary files and installs GRUB on
2735 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2736 more information, @pxref{Invoking guix system}. This command may trigger
2737 downloads or builds of missing packages, which can take some time.
2739 Once that command has completed---and hopefully succeeded!---you can run
2740 @command{reboot} and boot into the new system. The @code{root} password
2741 in the new system is initially empty; other users' passwords need to be
2742 initialized by running the @command{passwd} command as @code{root},
2743 unless your configuration specifies otherwise
2744 (@pxref{user-account-password, user account passwords}).
2745 @xref{After System Installation}, for what's next!
2748 @node After System Installation
2749 @section After System Installation
2751 Success, you've now booted into Guix System! From then on, you can update the
2752 system whenever you want by running, say:
2756 sudo guix system reconfigure /etc/config.scm
2760 This builds a new system generation with the latest packages and services
2761 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2762 your system includes the latest security updates (@pxref{Security Updates}).
2764 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2766 @cindex sudo vs. @command{guix pull}
2767 Note that @command{sudo guix} runs your user's @command{guix} command and
2768 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2769 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2771 The difference matters here, because @command{guix pull} updates
2772 the @command{guix} command and package definitions only for the user it is run
2773 as. This means that if you choose to use @command{guix system reconfigure} in
2774 root's login shell, you'll need to @command{guix pull} separately.
2777 Now, @pxref{Getting Started}, and
2778 join us on @code{#guix} on the Libera Chat IRC network or on
2779 @email{guix-devel@@gnu.org} to share your experience!
2782 @node Installing Guix in a VM
2783 @section Installing Guix in a Virtual Machine
2785 @cindex virtual machine, Guix System installation
2786 @cindex virtual private server (VPS)
2787 @cindex VPS (virtual private server)
2788 If you'd like to install Guix System in a virtual machine (VM) or on a
2789 virtual private server (VPS) rather than on your beloved machine, this
2792 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2793 disk image, follow these steps:
2797 First, retrieve and decompress the Guix system installation image as
2798 described previously (@pxref{USB Stick and DVD Installation}).
2801 Create a disk image that will hold the installed system. To make a
2802 qcow2-formatted disk image, use the @command{qemu-img} command:
2805 qemu-img create -f qcow2 guix-system.img 50G
2808 The resulting file will be much smaller than 50 GB (typically less than
2809 1 MB), but it will grow as the virtualized storage device is filled up.
2812 Boot the USB installation image in an VM:
2815 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2816 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2817 -drive file=guix-system.img \
2818 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2821 @code{-enable-kvm} is optional, but significantly improves performance,
2822 @pxref{Running Guix in a VM}.
2825 You're now root in the VM, proceed with the installation process.
2826 @xref{Preparing for Installation}, and follow the instructions.
2829 Once installation is complete, you can boot the system that's on your
2830 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2833 @node Building the Installation Image
2834 @section Building the Installation Image
2836 @cindex installation image
2837 The installation image described above was built using the @command{guix
2838 system} command, specifically:
2841 guix system image -t iso9660 gnu/system/install.scm
2844 Have a look at @file{gnu/system/install.scm} in the source tree,
2845 and see also @ref{Invoking guix system} for more information
2846 about the installation image.
2848 @section Building the Installation Image for ARM Boards
2850 Many ARM boards require a specific variant of the
2851 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2853 If you build a disk image and the bootloader is not available otherwise
2854 (on another boot drive etc), it's advisable to build an image that
2855 includes the bootloader, specifically:
2858 guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2861 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2862 board, a list of possible boards will be printed.
2864 @c *********************************************************************
2865 @cindex troubleshooting, guix system
2866 @cindex guix system troubleshooting
2867 @node System Troubleshooting Tips
2868 @chapter System Troubleshooting Tips
2870 Guix System allows rebooting into a previous generation should the last
2871 one be malfunctioning, which makes it quite robust against being broken
2872 irreversibly. This feature depends on GRUB being correctly functioning
2873 though, which means that if for whatever reasons your GRUB installation
2874 becomes corrupted during a system reconfiguration, you may not be able
2875 to easily boot into a previous generation. A technique that can be used
2876 in this case is to @i{chroot} into your broken system and reconfigure it
2877 from there. Such technique is explained below.
2879 @cindex chroot, guix system
2880 @cindex chrooting, guix system
2881 @cindex repairing GRUB, via chroot
2882 @node Chrooting into an existing system
2883 @section Chrooting into an existing system
2885 This section details how to @i{chroot} to an already installed Guix
2886 System with the aim of reconfiguring it, for example to fix a broken
2887 GRUB installation. The process is similar to how it would be done on
2888 other GNU/Linux systems, but there are some Guix System particularities
2889 such as the daemon and profiles that make it worthy of explaining here.
2893 Obtain a bootable image of Guix System. It is recommended the latest
2894 development snapshot so the kernel and the tools used are at least as as
2895 new as those of your installed system; it can be retrieved from the
2896 @url{https://ci.guix.gnu.org/search/latest/ISO-9660?query=spec:images+status:success+system:x86_64-linux+image.iso,
2897 https://ci.guix.gnu.org} URL. Follow the @pxref{USB Stick and DVD
2898 Installation} section for copying it to a bootable media.
2901 Boot the image, and proceed with the graphical text-based installer
2902 until your network is configured. Alternatively, you could configure
2903 the network manually by following the
2904 @ref{manual-installation-networking} section. If you get the error
2905 @samp{RTNETLINK answers: Operation not possible due to RF-kill}, try
2906 @samp{rfkill list} followed by @samp{rfkill unblock 0}, where @samp{0}
2907 is your device identifier (ID).
2910 Switch to a virtual console (tty) if you haven't already by pressing
2911 simultaneously the @kbd{Control + Alt + F4} keys. Mount your file
2912 system at @file{/mnt}. Assuming your root partition is
2913 @file{/dev/sda2}, you would do:
2916 mount /dev/sda2 /mnt
2920 Mount special block devices and Linux-specific directories:
2923 mount --bind /proc /mnt/proc
2924 mount --bind /sys /mnt/sys
2925 mount --bind /dev /mnt/dev
2928 If your system is EFI-based, you must also mount the ESP partition.
2929 Assuming it is @file{/dev/sda1}, you can do so with:
2932 mount /dev/sda1 /mnt/boot/efi
2936 Enter your system via chroot:
2943 Source the system profile as well as your @var{user} profile to setup
2944 the environment, where @var{user} is the user name used for the Guix
2945 System you are attempting to repair:
2948 source /var/guix/profiles/system/profile/etc/profile
2949 source /home/@var{user}/.guix-profile/etc/profile
2952 To ensure you are working with the Guix revision you normally would as
2953 your normal user, also source your current Guix profile:
2956 source /home/@var{user}/.config/guix/current/etc/profile
2960 Start a minimal @command{guix-daemon} in the background:
2963 guix-daemon --build-users-group=guixbuild --disable-chroot &
2967 Edit your Guix System configuration if needed, then reconfigure with:
2970 guix system reconfigure your-config.scm
2974 Finally, you should be good to reboot the system to test your fix.
2978 @c *********************************************************************
2979 @node Getting Started
2980 @chapter Getting Started
2982 Presumably, you've reached this section because either you have
2983 installed Guix on top of another distribution (@pxref{Installation}), or
2984 you've installed the standalone Guix System (@pxref{System
2985 Installation}). It's time for you to get started using Guix and this
2986 section aims to help you do that and give you a feel of what it's like.
2988 Guix is about installing software, so probably the first thing you'll
2989 want to do is to actually look for software. Let's say you're looking
2990 for a text editor, you can run:
2993 guix search text editor
2996 This command shows you a number of matching @dfn{packages}, each time
2997 showing the package's name, version, a description, and additional info.
2998 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2999 you can go ahead and install it (run this command as a regular user,
3000 @emph{no need for root privileges}!):
3007 You've installed your first package, congrats! The package is now
3008 visible in your default @dfn{profile}, @file{$HOME/.guix-profile}---a
3009 profile is a directory containing installed packages.
3010 In the process, you've
3011 probably noticed that Guix downloaded pre-built binaries; or, if you
3012 explicitly chose to @emph{not} use pre-built binaries, then probably
3013 Guix is still building software (@pxref{Substitutes}, for more info).
3015 Unless you're using Guix System, the @command{guix install} command must
3016 have printed this hint:
3019 hint: Consider setting the necessary environment variables by running:
3021 GUIX_PROFILE="$HOME/.guix-profile"
3022 . "$GUIX_PROFILE/etc/profile"
3024 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
3027 Indeed, you must now tell your shell where @command{emacs} and other
3028 programs installed with Guix are to be found. Pasting the two lines
3029 above will do just that: it will add
3030 @code{$HOME/.guix-profile/bin}---which is where the installed package
3031 is---to the @code{PATH} environment variable. You can paste these two
3032 lines in your shell so they take effect right away, but more importantly
3033 you should add them to @file{~/.bash_profile} (or equivalent file if you
3034 do not use Bash) so that environment variables are set next time you
3035 spawn a shell. You only need to do this once and other search paths
3036 environment variables will be taken care of similarly---e.g., if you
3037 eventually install @code{python} and Python libraries,
3038 @env{GUIX_PYTHONPATH} will be defined.
3040 You can go on installing packages at your will. To list installed
3044 guix package --list-installed
3047 To remove a package, you would unsurprisingly run @command{guix remove}.
3048 A distinguishing feature is the ability to @dfn{roll back} any operation
3049 you made---installation, removal, upgrade---by simply typing:
3052 guix package --roll-back
3055 This is because each operation is in fact a @dfn{transaction} that
3056 creates a new @dfn{generation}. These generations and the difference
3057 between them can be displayed by running:
3060 guix package --list-generations
3063 Now you know the basics of package management!
3065 @quotation Going further
3066 @xref{Package Management}, for more about package management. You may
3067 like @dfn{declarative} package management with @command{guix package
3068 --manifest}, managing separate @dfn{profiles} with @option{--profile},
3069 deleting old generations, collecting garbage, and other nifty features
3070 that will come in handy as you become more familiar with Guix. If you
3071 are a developer, @pxref{Development} for additional tools. And if
3072 you're curious, @pxref{Features}, to peek under the hood.
3075 Once you've installed a set of packages, you will want to periodically
3076 @emph{upgrade} them to the latest and greatest version. To do that, you
3077 will first pull the latest revision of Guix and its package collection:
3083 The end result is a new @command{guix} command, under
3084 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
3085 first time you run @command{guix pull}, be sure to follow the hint that
3086 the command prints and, similar to what we saw above, paste these two
3087 lines in your terminal and @file{.bash_profile}:
3090 GUIX_PROFILE="$HOME/.config/guix/current"
3091 . "$GUIX_PROFILE/etc/profile"
3095 You must also instruct your shell to point to this new @command{guix}:
3101 At this point, you're running a brand new Guix. You can thus go ahead
3102 and actually upgrade all the packages you previously installed:
3108 As you run this command, you will see that binaries are downloaded (or
3109 perhaps some packages are built), and eventually you end up with the
3110 upgraded packages. Should one of these upgraded packages not be to your
3111 liking, remember you can always roll back!
3113 You can display the exact revision of Guix you're currently using by
3120 The information it displays is @emph{all it takes to reproduce the exact
3121 same Guix}, be it at a different point in time or on a different
3124 @quotation Going further
3125 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
3126 how to specify additional @dfn{channels} to pull packages from, how to
3127 replicate Guix, and more. You may also find @command{time-machine}
3128 handy (@pxref{Invoking guix time-machine}).
3131 If you installed Guix System, one of the first things you'll want to do
3132 is to upgrade your system. Once you've run @command{guix pull} to get
3133 the latest Guix, you can upgrade the system like this:
3136 sudo guix system reconfigure /etc/config.scm
3139 Upon completion, the system runs the latest versions of its software
3140 packages. When you eventually reboot, you'll notice a sub-menu in the
3141 bootloader that reads ``Old system generations'': it's what allows you
3142 to boot @emph{an older generation of your system}, should the latest
3143 generation be ``broken'' or otherwise unsatisfying. Just like for
3144 packages, you can always @emph{roll back} to a previous generation
3145 @emph{of the whole system}:
3148 sudo guix system roll-back
3151 There are many things you'll probably want to tweak on your system:
3152 adding new user accounts, adding new system services, fiddling with the
3153 configuration of those services, etc. The system configuration is
3154 @emph{entirely} described in the @file{/etc/config.scm} file.
3155 @xref{Using the Configuration System}, to learn how to change it.
3157 Now you know enough to get started!
3159 @quotation Resources
3160 The rest of this manual provides a reference for all things Guix. Here
3161 are some additional resources you may find useful:
3165 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
3166 ``how-to'' style of recipes for a variety of applications.
3169 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
3170 Card} lists in two pages most of the commands and options you'll ever
3174 The web site contains @uref{https://guix.gnu.org/en/videos/,
3175 instructional videos} covering topics such as everyday use of Guix, how
3176 to get help, and how to become a contributor.
3179 @xref{Documentation}, to learn how to access documentation on your
3183 We hope you will enjoy Guix as much as the community enjoys building it!
3186 @c *********************************************************************
3187 @node Package Management
3188 @chapter Package Management
3191 The purpose of GNU Guix is to allow users to easily install, upgrade, and
3192 remove software packages, without having to know about their build
3193 procedures or dependencies. Guix also goes beyond this obvious set of
3196 This chapter describes the main features of Guix, as well as the
3197 package management tools it provides. Along with the command-line
3198 interface described below (@pxref{Invoking guix package, @code{guix
3199 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
3200 emacs-guix, The Emacs-Guix Reference Manual}), after installing
3201 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
3205 guix install emacs-guix
3209 * Features:: How Guix will make your life brighter.
3210 * Invoking guix package:: Package installation, removal, etc.
3211 * Substitutes:: Downloading pre-built binaries.
3212 * Packages with Multiple Outputs:: Single source package, multiple outputs.
3213 * Invoking guix gc:: Running the garbage collector.
3214 * Invoking guix pull:: Fetching the latest Guix and distribution.
3215 * Invoking guix time-machine:: Running an older revision of Guix.
3216 * Inferiors:: Interacting with another revision of Guix.
3217 * Invoking guix describe:: Display information about your Guix revision.
3218 * Invoking guix archive:: Exporting and importing store files.
3224 Here we assume you've already made your first steps with Guix
3225 (@pxref{Getting Started}) and would like to get an overview about what's
3226 going on under the hood.
3228 When using Guix, each package ends up in the @dfn{package store}, in its
3229 own directory---something that resembles
3230 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
3232 Instead of referring to these directories, users have their own
3233 @dfn{profile}, which points to the packages that they actually want to
3234 use. These profiles are stored within each user's home directory, at
3235 @code{$HOME/.guix-profile}.
3237 For example, @code{alice} installs GCC 4.7.2. As a result,
3238 @file{/home/alice/.guix-profile/bin/gcc} points to
3239 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
3240 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
3241 simply continues to point to
3242 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
3243 coexist on the same system without any interference.
3245 The @command{guix package} command is the central tool to manage
3246 packages (@pxref{Invoking guix package}). It operates on the per-user
3247 profiles, and can be used @emph{with normal user privileges}.
3249 @cindex transactions
3250 The command provides the obvious install, remove, and upgrade
3251 operations. Each invocation is actually a @emph{transaction}: either
3252 the specified operation succeeds, or nothing happens. Thus, if the
3253 @command{guix package} process is terminated during the transaction,
3254 or if a power outage occurs during the transaction, then the user's
3255 profile remains in its previous state, and remains usable.
3257 In addition, any package transaction may be @emph{rolled back}. So, if,
3258 for example, an upgrade installs a new version of a package that turns
3259 out to have a serious bug, users may roll back to the previous instance
3260 of their profile, which was known to work well. Similarly, the global
3261 system configuration on Guix is subject to
3262 transactional upgrades and roll-back
3263 (@pxref{Using the Configuration System}).
3265 All packages in the package store may be @emph{garbage-collected}.
3266 Guix can determine which packages are still referenced by user
3267 profiles, and remove those that are provably no longer referenced
3268 (@pxref{Invoking guix gc}). Users may also explicitly remove old
3269 generations of their profile so that the packages they refer to can be
3272 @cindex reproducibility
3273 @cindex reproducible builds
3274 Guix takes a @dfn{purely functional} approach to package
3275 management, as described in the introduction (@pxref{Introduction}).
3276 Each @file{/gnu/store} package directory name contains a hash of all the
3277 inputs that were used to build that package---compiler, libraries, build
3278 scripts, etc. This direct correspondence allows users to make sure a
3279 given package installation matches the current state of their
3280 distribution. It also helps maximize @dfn{build reproducibility}:
3281 thanks to the isolated build environments that are used, a given build
3282 is likely to yield bit-identical files when performed on different
3283 machines (@pxref{Invoking guix-daemon, container}).
3286 This foundation allows Guix to support @dfn{transparent binary/source
3287 deployment}. When a pre-built binary for a @file{/gnu/store} item is
3288 available from an external source---a @dfn{substitute}, Guix just
3289 downloads it and unpacks it;
3290 otherwise, it builds the package from source, locally
3291 (@pxref{Substitutes}). Because build results are usually bit-for-bit
3292 reproducible, users do not have to trust servers that provide
3293 substitutes: they can force a local build and @emph{challenge} providers
3294 (@pxref{Invoking guix challenge}).
3296 Control over the build environment is a feature that is also useful for
3297 developers. The @command{guix shell} command allows developers of
3298 a package to quickly set up the right development environment for their
3299 package, without having to manually install the dependencies of the
3300 package into their profile (@pxref{Invoking guix shell}).
3302 @cindex replication, of software environments
3303 @cindex provenance tracking, of software artifacts
3304 All of Guix and its package definitions is version-controlled, and
3305 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3306 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3307 Guix instance on a different machine or at a later point in time, which in
3308 turn allows you to @emph{replicate complete software environments}, while
3309 retaining precise @dfn{provenance tracking} of the software.
3311 @node Invoking guix package
3312 @section Invoking @command{guix package}
3314 @cindex installing packages
3315 @cindex removing packages
3316 @cindex package installation
3317 @cindex package removal
3319 @cindex @command{guix package}
3320 The @command{guix package} command is the tool that allows users to
3321 install, upgrade, and remove packages, as well as rolling back to
3322 previous configurations. These operations work on a user
3323 @dfn{profile}---a directory of installed packages. Each user has a
3324 default profile in @file{$HOME/.guix-profile}.
3325 The command operates only on the user's own profile,
3326 and works with normal user privileges (@pxref{Features}). Its syntax
3330 guix package @var{options}
3333 @cindex transactions
3334 Primarily, @var{options} specifies the operations to be performed during
3335 the transaction. Upon completion, a new profile is created, but
3336 previous @dfn{generations} of the profile remain available, should the user
3339 For example, to remove @code{lua} and install @code{guile} and
3340 @code{guile-cairo} in a single transaction:
3343 guix package -r lua -i guile guile-cairo
3346 @cindex aliases, for @command{guix package}
3347 For your convenience, we also provide the following aliases:
3351 @command{guix search} is an alias for @command{guix package -s},
3353 @command{guix install} is an alias for @command{guix package -i},
3355 @command{guix remove} is an alias for @command{guix package -r},
3357 @command{guix upgrade} is an alias for @command{guix package -u},
3359 and @command{guix show} is an alias for @command{guix package --show=}.
3362 These aliases are less expressive than @command{guix package} and provide
3363 fewer options, so in some cases you'll probably want to use @command{guix
3366 @command{guix package} also supports a @dfn{declarative approach}
3367 whereby the user specifies the exact set of packages to be available and
3368 passes it @i{via} the @option{--manifest} option
3369 (@pxref{profile-manifest, @option{--manifest}}).
3372 For each user, a symlink to the user's default profile is automatically
3373 created in @file{$HOME/.guix-profile}. This symlink always points to the
3374 current generation of the user's default profile. Thus, users can add
3375 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3376 variable, and so on.
3377 @cindex search paths
3378 If you are not using Guix System, consider adding the
3379 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3380 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3381 shells get all the right environment variable definitions:
3384 GUIX_PROFILE="$HOME/.guix-profile" ; \
3385 source "$GUIX_PROFILE/etc/profile"
3388 In a multi-user setup, user profiles are stored in a place registered as
3389 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3390 to (@pxref{Invoking guix gc}). That directory is normally
3391 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3392 @var{localstatedir} is the value passed to @code{configure} as
3393 @option{--localstatedir}, and @var{user} is the user name. The
3394 @file{per-user} directory is created when @command{guix-daemon} is
3395 started, and the @var{user} sub-directory is created by @command{guix
3398 The @var{options} can be among the following:
3402 @item --install=@var{package} @dots{}
3403 @itemx -i @var{package} @dots{}
3404 Install the specified @var{package}s.
3406 Each @var{package} may specify either a simple package name, such as
3407 @code{guile}, or a package name followed by an at-sign and version number,
3408 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3409 case, the newest version prefixed by @code{1.8} is selected).
3411 If no version number is specified, the
3412 newest available version will be selected. In addition, @var{package}
3413 may contain a colon, followed by the name of one of the outputs of the
3414 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3415 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3416 name (and optionally version) are searched for among the GNU
3417 distribution modules (@pxref{Package Modules}).
3419 @cindex propagated inputs
3420 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3421 that automatically get installed along with the required package
3422 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3423 @code{package} objects}, for information about propagated inputs in
3424 package definitions).
3426 @anchor{package-cmd-propagated-inputs}
3427 An example is the GNU MPC library: its C header files refer to those of
3428 the GNU MPFR library, which in turn refer to those of the GMP library.
3429 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3430 in the profile; removing MPC also removes MPFR and GMP---unless they had
3431 also been explicitly installed by the user.
3433 Besides, packages sometimes rely on the definition of environment
3434 variables for their search paths (see explanation of
3435 @option{--search-paths} below). Any missing or possibly incorrect
3436 environment variable definitions are reported here.
3438 @item --install-from-expression=@var{exp}
3440 Install the package @var{exp} evaluates to.
3442 @var{exp} must be a Scheme expression that evaluates to a
3443 @code{<package>} object. This option is notably useful to disambiguate
3444 between same-named variants of a package, with expressions such as
3445 @code{(@@ (gnu packages base) guile-final)}.
3447 Note that this option installs the first output of the specified
3448 package, which may be insufficient when needing a specific output of a
3449 multiple-output package.
3451 @item --install-from-file=@var{file}
3452 @itemx -f @var{file}
3453 Install the package that the code within @var{file} evaluates to.
3455 As an example, @var{file} might contain a definition like this
3456 (@pxref{Defining Packages}):
3459 @include package-hello.scm
3462 Developers may find it useful to include such a @file{guix.scm} file
3463 in the root of their project source tree that can be used to test
3464 development snapshots and create reproducible development environments
3465 (@pxref{Invoking guix shell}).
3467 The @var{file} may also contain a JSON representation of one or more
3468 package definitions. Running @code{guix package -f} on
3469 @file{hello.json} with the following contents would result in installing
3470 the package @code{greeter} after building @code{myhello}:
3473 @verbatiminclude package-hello.json
3476 @item --remove=@var{package} @dots{}
3477 @itemx -r @var{package} @dots{}
3478 Remove the specified @var{package}s.
3480 As for @option{--install}, each @var{package} may specify a version number
3481 and/or output name in addition to the package name. For instance,
3482 @samp{-r glibc:debug} would remove the @code{debug} output of
3485 @item --upgrade[=@var{regexp} @dots{}]
3486 @itemx -u [@var{regexp} @dots{}]
3487 @cindex upgrading packages
3488 Upgrade all the installed packages. If one or more @var{regexp}s are
3489 specified, upgrade only installed packages whose name matches a
3490 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3492 Note that this upgrades package to the latest version of packages found
3493 in the distribution currently installed. To update your distribution,
3494 you should regularly run @command{guix pull} (@pxref{Invoking guix
3497 @cindex package transformations, upgrades
3498 When upgrading, package transformations that were originally applied
3499 when creating the profile are automatically re-applied (@pxref{Package
3500 Transformation Options}). For example, assume you first installed Emacs
3501 from the tip of its development branch with:
3504 guix install emacs-next --with-branch=emacs-next=master
3507 Next time you run @command{guix upgrade}, Guix will again pull the tip
3508 of the Emacs development branch and build @code{emacs-next} from that
3511 Note that transformation options such as @option{--with-branch} and
3512 @option{--with-source} depend on external state; it is up to you to
3513 ensure that they work as expected. You can also discard a
3514 transformations that apply to a package by running:
3517 guix install @var{package}
3520 @item --do-not-upgrade[=@var{regexp} @dots{}]
3521 When used together with the @option{--upgrade} option, do @emph{not}
3522 upgrade any packages whose name matches a @var{regexp}. For example, to
3523 upgrade all packages in the current profile except those containing the
3524 substring ``emacs'':
3527 $ guix package --upgrade . --do-not-upgrade emacs
3530 @item @anchor{profile-manifest}--manifest=@var{file}
3531 @itemx -m @var{file}
3532 @cindex profile declaration
3533 @cindex profile manifest
3534 Create a new generation of the profile from the manifest object
3535 returned by the Scheme code in @var{file}. This option can be repeated
3536 several times, in which case the manifests are concatenated.
3538 This allows you to @emph{declare} the profile's contents rather than
3539 constructing it through a sequence of @option{--install} and similar
3540 commands. The advantage is that @var{file} can be put under version
3541 control, copied to different machines to reproduce the same profile, and
3544 @var{file} must return a @dfn{manifest} object, which is roughly a list
3547 @findex packages->manifest
3549 (use-package-modules guile emacs)
3554 ;; Use a specific package output.
3555 (list guile-2.0 "debug")))
3558 @xref{Writing Manifests}, for information on how to write a manifest.
3559 @xref{export-manifest, @option{--export-manifest}}, to learn how to
3560 obtain a manifest file from an existing profile.
3563 @cindex rolling back
3564 @cindex undoing transactions
3565 @cindex transactions, undoing
3566 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3567 the last transaction.
3569 When combined with options such as @option{--install}, roll back occurs
3570 before any other actions.
3572 When rolling back from the first generation that actually contains
3573 installed packages, the profile is made to point to the @dfn{zeroth
3574 generation}, which contains no files apart from its own metadata.
3576 After having rolled back, installing, removing, or upgrading packages
3577 overwrites previous future generations. Thus, the history of the
3578 generations in a profile is always linear.
3580 @item --switch-generation=@var{pattern}
3581 @itemx -S @var{pattern}
3583 Switch to a particular generation defined by @var{pattern}.
3585 @var{pattern} may be either a generation number or a number prefixed
3586 with ``+'' or ``-''. The latter means: move forward/backward by a
3587 specified number of generations. For example, if you want to return to
3588 the latest generation after @option{--roll-back}, use
3589 @option{--switch-generation=+1}.
3591 The difference between @option{--roll-back} and
3592 @option{--switch-generation=-1} is that @option{--switch-generation} will
3593 not make a zeroth generation, so if a specified generation does not
3594 exist, the current generation will not be changed.
3596 @item --search-paths[=@var{kind}]
3597 @cindex search paths
3598 Report environment variable definitions, in Bash syntax, that may be
3599 needed in order to use the set of installed packages. These environment
3600 variables are used to specify @dfn{search paths} for files used by some
3601 of the installed packages.
3603 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3604 environment variables to be defined so it can look for headers and
3605 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3606 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3607 library are installed in the profile, then @option{--search-paths} will
3608 suggest setting these variables to @file{@var{profile}/include} and
3609 @file{@var{profile}/lib}, respectively (@pxref{Search Paths}, for info
3610 on search path specifications associated with packages.)
3612 The typical use case is to define these environment variables in the
3616 $ eval $(guix package --search-paths)
3619 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3620 meaning that the returned environment variable definitions will either
3621 be exact settings, or prefixes or suffixes of the current value of these
3622 variables. When omitted, @var{kind} defaults to @code{exact}.
3624 This option can also be used to compute the @emph{combined} search paths
3625 of several profiles. Consider this example:
3628 $ guix package -p foo -i guile
3629 $ guix package -p bar -i guile-json
3630 $ guix package -p foo -p bar --search-paths
3633 The last command above reports about the @env{GUILE_LOAD_PATH}
3634 variable, even though, taken individually, neither @file{foo} nor
3635 @file{bar} would lead to that recommendation.
3638 @cindex profile, choosing
3639 @item --profile=@var{profile}
3640 @itemx -p @var{profile}
3641 Use @var{profile} instead of the user's default profile.
3643 @var{profile} must be the name of a file that will be created upon
3644 completion. Concretely, @var{profile} will be a mere symbolic link
3645 (``symlink'') pointing to the actual profile where packages are
3649 $ guix install hello -p ~/code/my-profile
3651 $ ~/code/my-profile/bin/hello
3655 All it takes to get rid of the profile is to remove this symlink and its
3656 siblings that point to specific generations:
3659 $ rm ~/code/my-profile ~/code/my-profile-*-link
3662 @item --list-profiles
3663 List all the user's profiles:
3666 $ guix package --list-profiles
3667 /home/charlie/.guix-profile
3668 /home/charlie/code/my-profile
3669 /home/charlie/code/devel-profile
3670 /home/charlie/tmp/test
3673 When running as root, list all the profiles of all the users.
3675 @cindex collisions, in a profile
3676 @cindex colliding packages in profiles
3677 @cindex profile collisions
3678 @item --allow-collisions
3679 Allow colliding packages in the new profile. Use at your own risk!
3681 By default, @command{guix package} reports as an error @dfn{collisions}
3682 in the profile. Collisions happen when two or more different versions
3683 or variants of a given package end up in the profile.
3686 Use the bootstrap Guile to build the profile. This option is only
3687 useful to distribution developers.
3691 In addition to these actions, @command{guix package} supports the
3692 following options to query the current state of a profile, or the
3693 availability of packages:
3697 @item --search=@var{regexp}
3698 @itemx -s @var{regexp}
3699 @anchor{guix-search}
3700 @cindex searching for packages
3701 List the available packages whose name, synopsis, or description matches
3702 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3703 Print all the metadata of matching packages in
3704 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3705 GNU recutils manual}).
3707 This allows specific fields to be extracted using the @command{recsel}
3708 command, for instance:
3711 $ guix package -s malloc | recsel -p name,version,relevance
3725 Similarly, to show the name of all the packages available under the
3726 terms of the GNU@tie{}LGPL version 3:
3729 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3736 It is also possible to refine search results using several @code{-s} flags to
3737 @command{guix package}, or several arguments to @command{guix search}. For
3738 example, the following command returns a list of board games (this time using
3739 the @command{guix search} alias):
3742 $ guix search '\<board\>' game | recsel -p name
3747 If we were to omit @code{-s game}, we would also get software packages
3748 that deal with printed circuit boards; removing the angle brackets
3749 around @code{board} would further add packages that have to do with
3752 And now for a more elaborate example. The following command searches
3753 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3754 libraries, and prints the name and synopsis of the matching packages:
3757 $ guix search crypto library | \
3758 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3762 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3763 information on @dfn{selection expressions} for @code{recsel -e}.
3765 @item --show=@var{package}
3766 Show details about @var{package}, taken from the list of available packages, in
3767 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3771 $ guix package --show=guile | recsel -p name,version
3783 You may also specify the full name of a package to only get details about a
3784 specific version of it (this time using the @command{guix show} alias):
3786 $ guix show guile@@3.0.5 | recsel -p name,version
3791 @item --list-installed[=@var{regexp}]
3792 @itemx -I [@var{regexp}]
3793 List the currently installed packages in the specified profile, with the
3794 most recently installed packages shown last. When @var{regexp} is
3795 specified, list only installed packages whose name matches @var{regexp}.
3797 For each installed package, print the following items, separated by
3798 tabs: the package name, its version string, the part of the package that
3799 is installed (for instance, @code{out} for the default output,
3800 @code{include} for its headers, etc.), and the path of this package in
3803 @item --list-available[=@var{regexp}]
3804 @itemx -A [@var{regexp}]
3805 List packages currently available in the distribution for this system
3806 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3807 available packages whose name matches @var{regexp}.
3809 For each package, print the following items separated by tabs: its name,
3810 its version string, the parts of the package (@pxref{Packages with
3811 Multiple Outputs}), and the source location of its definition.
3813 @item --list-generations[=@var{pattern}]
3814 @itemx -l [@var{pattern}]
3816 Return a list of generations along with their creation dates; for each
3817 generation, show the installed packages, with the most recently
3818 installed packages shown last. Note that the zeroth generation is never
3821 For each installed package, print the following items, separated by
3822 tabs: the name of a package, its version string, the part of the package
3823 that is installed (@pxref{Packages with Multiple Outputs}), and the
3824 location of this package in the store.
3826 When @var{pattern} is used, the command returns only matching
3827 generations. Valid patterns include:
3830 @item @emph{Integers and comma-separated integers}. Both patterns denote
3831 generation numbers. For instance, @option{--list-generations=1} returns
3834 And @option{--list-generations=1,8,2} outputs three generations in the
3835 specified order. Neither spaces nor trailing commas are allowed.
3837 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3838 specified generations and everything in between. Note that the start of
3839 a range must be smaller than its end.
3841 It is also possible to omit the endpoint. For example,
3842 @option{--list-generations=2..}, returns all generations starting from the
3845 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3846 or months by passing an integer along with the first letter of the
3847 duration. For example, @option{--list-generations=20d} lists generations
3848 that are up to 20 days old.
3851 @item --delete-generations[=@var{pattern}]
3852 @itemx -d [@var{pattern}]
3853 When @var{pattern} is omitted, delete all generations except the current
3856 This command accepts the same patterns as @option{--list-generations}.
3857 When @var{pattern} is specified, delete the matching generations. When
3858 @var{pattern} specifies a duration, generations @emph{older} than the
3859 specified duration match. For instance, @option{--delete-generations=1m}
3860 deletes generations that are more than one month old.
3862 If the current generation matches, it is @emph{not} deleted. Also, the
3863 zeroth generation is never deleted.
3865 Note that deleting generations prevents rolling back to them.
3866 Consequently, this command must be used with care.
3868 @cindex manifest, exporting
3869 @anchor{export-manifest}
3870 @item --export-manifest
3871 Write to standard output a manifest suitable for @option{--manifest}
3872 corresponding to the chosen profile(s).
3874 This option is meant to help you migrate from the ``imperative''
3875 operating mode---running @command{guix install}, @command{guix upgrade},
3876 etc.---to the declarative mode that @option{--manifest} offers.
3878 Be aware that the resulting manifest @emph{approximates} what your
3879 profile actually contains; for instance, depending on how your profile
3880 was created, it can refer to packages or package versions that are not
3881 exactly what you specified.
3883 Keep in mind that a manifest is purely symbolic: it only contains
3884 package names and possibly versions, and their meaning varies over time.
3885 If you wish to ``pin'' channels to the revisions that were used to build
3886 the profile(s), see @option{--export-channels} below.
3888 @cindex pinning, channel revisions of a profile
3889 @item --export-channels
3890 Write to standard output the list of channels used by the chosen
3891 profile(s), in a format suitable for @command{guix pull --channels} or
3892 @command{guix time-machine --channels} (@pxref{Channels}).
3894 Together with @option{--export-manifest}, this option provides
3895 information allowing you to replicate the current profile
3896 (@pxref{Replicating Guix}).
3898 However, note that the output of this command @emph{approximates} what
3899 was actually used to build this profile. In particular, a single
3900 profile might have been built from several different revisions of the
3901 same channel. In that case, @option{--export-manifest} chooses the last
3902 one and writes the list of other revisions in a comment. If you really
3903 need to pick packages from different channel revisions, you can use
3904 inferiors in your manifest to do so (@pxref{Inferiors}).
3906 Together with @option{--export-manifest}, this is a good starting point
3907 if you are willing to migrate from the ``imperative'' model to the fully
3908 declarative model consisting of a manifest file along with a channels
3909 file pinning the exact channel revision(s) you want.
3912 Finally, since @command{guix package} may actually start build
3913 processes, it supports all the common build options (@pxref{Common Build
3914 Options}). It also supports package transformation options, such as
3915 @option{--with-source}, and preserves them across upgrades
3916 (@pxref{Package Transformation Options}).
3919 @section Substitutes
3922 @cindex pre-built binaries
3923 Guix supports transparent source/binary deployment, which means that it
3924 can either build things locally, or download pre-built items from a
3925 server, or both. We call these pre-built items @dfn{substitutes}---they
3926 are substitutes for local build results. In many cases, downloading a
3927 substitute is much faster than building things locally.
3929 Substitutes can be anything resulting from a derivation build
3930 (@pxref{Derivations}). Of course, in the common case, they are
3931 pre-built package binaries, but source tarballs, for instance, which
3932 also result from derivation builds, can be available as substitutes.
3935 * Official Substitute Servers:: One particular source of substitutes.
3936 * Substitute Server Authorization:: How to enable or disable substitutes.
3937 * Getting Substitutes from Other Servers:: Substitute diversity.
3938 * Substitute Authentication:: How Guix verifies substitutes.
3939 * Proxy Settings:: How to get substitutes via proxy.
3940 * Substitution Failure:: What happens when substitution fails.
3941 * On Trusting Binaries:: How can you trust that binary blob?
3944 @node Official Substitute Servers
3945 @subsection Official Substitute Servers
3948 @code{@value{SUBSTITUTE-SERVER-1}} and
3949 @code{@value{SUBSTITUTE-SERVER-2}} are both front-ends to official build
3950 farms that build packages from Guix continuously for some architectures,
3951 and make them available as substitutes. These are the default source of
3952 substitutes; which can be overridden by passing the
3953 @option{--substitute-urls} option either to @command{guix-daemon}
3954 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3955 or to client tools such as @command{guix package}
3956 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3959 Substitute URLs can be either HTTP or HTTPS.
3960 HTTPS is recommended because communications are encrypted; conversely,
3961 using HTTP makes all communications visible to an eavesdropper, who
3962 could use the information gathered to determine, for instance, whether
3963 your system has unpatched security vulnerabilities.
3965 Substitutes from the official build farms are enabled by default when
3966 using Guix System (@pxref{GNU Distribution}). However,
3967 they are disabled by default when using Guix on a foreign distribution,
3968 unless you have explicitly enabled them via one of the recommended
3969 installation steps (@pxref{Installation}). The following paragraphs
3970 describe how to enable or disable substitutes for the official build
3971 farm; the same procedure can also be used to enable substitutes for any
3972 other substitute server.
3974 @node Substitute Server Authorization
3975 @subsection Substitute Server Authorization
3978 @cindex substitutes, authorization thereof
3979 @cindex access control list (ACL), for substitutes
3980 @cindex ACL (access control list), for substitutes
3981 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER-1}}, @code{@value{SUBSTITUTE-SERVER-2}} or a mirror, you
3982 must add the relevant public key to the access control list (ACL) of archive
3983 imports, using the @command{guix archive} command (@pxref{Invoking guix
3984 archive}). Doing so implies that you trust the substitute server to not
3985 be compromised and to serve genuine substitutes.
3988 If you are using Guix System, you can skip this section: Guix System
3989 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER-1}} and
3990 @code{@value{SUBSTITUTE-SERVER-2}} by default.
3993 The public keys for each of the project maintained substitute servers
3994 are installed along with Guix, in @code{@var{prefix}/share/guix/}, where
3995 @var{prefix} is the installation prefix of Guix. If you installed Guix
3996 from source, make sure you checked the GPG signature of
3997 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3998 Then, you can run something like this:
4001 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER-1}.pub
4002 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER-2}.pub
4005 Once this is in place, the output of a command like @code{guix build}
4006 should change from something like:
4009 $ guix build emacs --dry-run
4010 The following derivations would be built:
4011 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
4012 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
4013 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
4014 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
4022 $ guix build emacs --dry-run
4023 112.3 MB would be downloaded:
4024 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
4025 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
4026 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
4027 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
4032 The text changed from ``The following derivations would be built'' to
4033 ``112.3 MB would be downloaded''. This indicates that substitutes from
4034 the configured substitute servers are usable and will be downloaded,
4035 when possible, for future builds.
4037 @cindex substitutes, how to disable
4038 The substitute mechanism can be disabled globally by running
4039 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
4040 guix-daemon}). It can also be disabled temporarily by passing the
4041 @option{--no-substitutes} option to @command{guix package},
4042 @command{guix build}, and other command-line tools.
4044 @node Getting Substitutes from Other Servers
4045 @subsection Getting Substitutes from Other Servers
4047 @cindex substitute servers, adding more
4048 Guix can look up and fetch substitutes from several servers. This is
4049 useful when you are using packages from additional channels for which
4050 the official server does not have substitutes but another server
4051 provides them. Another situation where this is useful is when you would
4052 prefer to download from your organization's substitute server, resorting
4053 to the official server only as a fallback or dismissing it altogether.
4055 You can give Guix a list of substitute server URLs and it will check
4056 them in the specified order. You also need to explicitly authorize the
4057 public keys of substitute servers to instruct Guix to accept the
4058 substitutes they sign.
4060 On Guix System, this is achieved by modifying the configuration of the
4061 @code{guix} service. Since the @code{guix} service is part of the
4062 default lists of services, @code{%base-services} and
4063 @code{%desktop-services}, you can use @code{modify-services} to change
4064 its configuration and add the URLs and substitute keys that you want
4065 (@pxref{Service Reference, @code{modify-services}}).
4067 As an example, suppose you want to fetch substitutes from
4068 @code{guix.example.org} and to authorize the signing key of that server,
4069 in addition to the default @code{@value{SUBSTITUTE-SERVER-1}} and
4070 @code{@value{SUBSTITUTE-SERVER-2}}. The resulting operating system
4071 configuration will look something like:
4077 ;; Assume we're starting from '%desktop-services'. Replace it
4078 ;; with the list of services you're actually using.
4079 (modify-services %desktop-services
4080 (guix-service-type config =>
4084 (append (list "https://guix.example.org")
4085 %default-substitute-urls))
4087 (append (list (local-file "./key.pub"))
4088 %default-authorized-guix-keys)))))))
4091 This assumes that the file @file{key.pub} contains the signing key of
4092 @code{guix.example.org}. With this change in place in your operating
4093 system configuration file (say @file{/etc/config.scm}), you can
4094 reconfigure and restart the @code{guix-daemon} service or reboot so the
4095 changes take effect:
4098 $ sudo guix system reconfigure /etc/config.scm
4099 $ sudo herd restart guix-daemon
4102 If you're running Guix on a ``foreign distro'', you would instead take
4103 the following steps to get substitutes from additional servers:
4107 Edit the service configuration file for @code{guix-daemon}; when using
4108 systemd, this is normally
4109 @file{/etc/systemd/system/guix-daemon.service}. Add the
4110 @option{--substitute-urls} option on the @command{guix-daemon} command
4111 line and list the URLs of interest (@pxref{daemon-substitute-urls,
4112 @code{guix-daemon --substitute-urls}}):
4115 @dots{} --substitute-urls='https://guix.example.org @value{SUBSTITUTE-URLS}'
4119 Restart the daemon. For systemd, it goes like this:
4122 systemctl daemon-reload
4123 systemctl restart guix-daemon.service
4127 Authorize the key of the new server (@pxref{Invoking guix archive}):
4130 guix archive --authorize < key.pub
4133 Again this assumes @file{key.pub} contains the public key that
4134 @code{guix.example.org} uses to sign substitutes.
4137 Now you're all set! Substitutes will be preferably taken from
4138 @code{https://guix.example.org}, using
4139 @code{@value{SUBSTITUTE-SERVER-1}} then
4140 @code{@value{SUBSTITUTE-SERVER-2}} as fallback options. Of course you
4141 can list as many substitute servers as you like, with the caveat that
4142 substitute lookup can be slowed down if too many servers need to be
4145 Note that there are also situations where one may want to add the URL of
4146 a substitute server @emph{without} authorizing its key.
4147 @xref{Substitute Authentication}, to understand this fine point.
4149 @node Substitute Authentication
4150 @subsection Substitute Authentication
4152 @cindex digital signatures
4153 Guix detects and raises an error when attempting to use a substitute
4154 that has been tampered with. Likewise, it ignores substitutes that are
4155 not signed, or that are not signed by one of the keys listed in the ACL.
4157 There is one exception though: if an unauthorized server provides
4158 substitutes that are @emph{bit-for-bit identical} to those provided by
4159 an authorized server, then the unauthorized server becomes eligible for
4160 downloads. For example, assume we have chosen two substitute servers
4164 --substitute-urls="https://a.example.org https://b.example.org"
4168 @cindex reproducible builds
4169 If the ACL contains only the key for @samp{b.example.org}, and if
4170 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
4171 then Guix will download substitutes from @samp{a.example.org} because it
4172 comes first in the list and can be considered a mirror of
4173 @samp{b.example.org}. In practice, independent build machines usually
4174 produce the same binaries, thanks to bit-reproducible builds (see
4177 When using HTTPS, the server's X.509 certificate is @emph{not} validated
4178 (in other words, the server is not authenticated), contrary to what
4179 HTTPS clients such as Web browsers usually do. This is because Guix
4180 authenticates substitute information itself, as explained above, which
4181 is what we care about (whereas X.509 certificates are about
4182 authenticating bindings between domain names and public keys).
4184 @node Proxy Settings
4185 @subsection Proxy Settings
4189 Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
4190 @env{https_proxy} environment variables can be set in the environment of
4191 @command{guix-daemon} and are honored for downloads of substitutes.
4192 Note that the value of those environment variables in the environment
4193 where @command{guix build}, @command{guix package}, and other client
4194 commands are run has @emph{absolutely no effect}.
4196 @node Substitution Failure
4197 @subsection Substitution Failure
4199 Even when a substitute for a derivation is available, sometimes the
4200 substitution attempt will fail. This can happen for a variety of
4201 reasons: the substitute server might be offline, the substitute may
4202 recently have been deleted, the connection might have been interrupted,
4205 When substitutes are enabled and a substitute for a derivation is
4206 available, but the substitution attempt fails, Guix will attempt to
4207 build the derivation locally depending on whether or not
4208 @option{--fallback} was given (@pxref{fallback-option,, common build
4209 option @option{--fallback}}). Specifically, if @option{--fallback} was
4210 omitted, then no local build will be performed, and the derivation is
4211 considered to have failed. However, if @option{--fallback} was given,
4212 then Guix will attempt to build the derivation locally, and the success
4213 or failure of the derivation depends on the success or failure of the
4214 local build. Note that when substitutes are disabled or no substitute
4215 is available for the derivation in question, a local build will
4216 @emph{always} be performed, regardless of whether or not
4217 @option{--fallback} was given.
4219 To get an idea of how many substitutes are available right now, you can
4220 try running the @command{guix weather} command (@pxref{Invoking guix
4221 weather}). This command provides statistics on the substitutes provided
4224 @node On Trusting Binaries
4225 @subsection On Trusting Binaries
4227 @cindex trust, of pre-built binaries
4228 Today, each individual's control over their own computing is at the
4229 mercy of institutions, corporations, and groups with enough power and
4230 determination to subvert the computing infrastructure and exploit its
4231 weaknesses. While using substitutes can be convenient, we encourage
4232 users to also build on their own, or even run their own build farm, such
4233 that the project run substitute servers are less of an interesting
4234 target. One way to help is by publishing the software you build using
4235 @command{guix publish} so that others have one more choice of server to
4236 download substitutes from (@pxref{Invoking guix publish}).
4238 Guix has the foundations to maximize build reproducibility
4239 (@pxref{Features}). In most cases, independent builds of a given
4240 package or derivation should yield bit-identical results. Thus, through
4241 a diverse set of independent package builds, we can strengthen the
4242 integrity of our systems. The @command{guix challenge} command aims to
4243 help users assess substitute servers, and to assist developers in
4244 finding out about non-deterministic package builds (@pxref{Invoking guix
4245 challenge}). Similarly, the @option{--check} option of @command{guix
4246 build} allows users to check whether previously-installed substitutes
4247 are genuine by rebuilding them locally (@pxref{build-check,
4248 @command{guix build --check}}).
4250 In the future, we want Guix to have support to publish and retrieve
4251 binaries to/from other users, in a peer-to-peer fashion. If you would
4252 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
4254 @node Packages with Multiple Outputs
4255 @section Packages with Multiple Outputs
4257 @cindex multiple-output packages
4258 @cindex package outputs
4261 Often, packages defined in Guix have a single @dfn{output}---i.e., the
4262 source package leads to exactly one directory in the store. When running
4263 @command{guix install glibc}, one installs the default output of the
4264 GNU libc package; the default output is called @code{out}, but its name
4265 can be omitted as shown in this command. In this particular case, the
4266 default output of @code{glibc} contains all the C header files, shared
4267 libraries, static libraries, Info documentation, and other supporting
4270 Sometimes it is more appropriate to separate the various types of files
4271 produced from a single source package into separate outputs. For
4272 instance, the GLib C library (used by GTK+ and related packages)
4273 installs more than 20 MiB of reference documentation as HTML pages.
4274 To save space for users who do not need it, the documentation goes to a
4275 separate output, called @code{doc}. To install the main GLib output,
4276 which contains everything but the documentation, one would run:
4282 @cindex documentation
4283 The command to install its documentation is:
4286 guix install glib:doc
4289 Some packages install programs with different ``dependency footprints''.
4290 For instance, the WordNet package installs both command-line tools and
4291 graphical user interfaces (GUIs). The former depend solely on the C
4292 library, whereas the latter depend on Tcl/Tk and the underlying X
4293 libraries. In this case, we leave the command-line tools in the default
4294 output, whereas the GUIs are in a separate output. This allows users
4295 who do not need the GUIs to save space. The @command{guix size} command
4296 can help find out about such situations (@pxref{Invoking guix size}).
4297 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
4299 There are several such multiple-output packages in the GNU distribution.
4300 Other conventional output names include @code{lib} for libraries and
4301 possibly header files, @code{bin} for stand-alone programs, and
4302 @code{debug} for debugging information (@pxref{Installing Debugging
4303 Files}). The outputs of a packages are listed in the third column of
4304 the output of @command{guix package --list-available} (@pxref{Invoking
4308 @node Invoking guix gc
4309 @section Invoking @command{guix gc}
4311 @cindex garbage collector
4313 @cindex @command{guix gc}
4314 Packages that are installed, but not used, may be @dfn{garbage-collected}.
4315 The @command{guix gc} command allows users to explicitly run the garbage
4316 collector to reclaim space from the @file{/gnu/store} directory. It is
4317 the @emph{only} way to remove files from @file{/gnu/store}---removing
4318 files or directories manually may break it beyond repair!
4321 @cindex garbage collector roots
4322 The garbage collector has a set of known @dfn{roots}: any file under
4323 @file{/gnu/store} reachable from a root is considered @dfn{live} and
4324 cannot be deleted; any other file is considered @dfn{dead} and may be
4325 deleted. The set of garbage collector roots (``GC roots'' for short)
4326 includes default user profiles; by default, the symlinks under
4327 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
4328 added with @command{guix build --root}, for example (@pxref{Invoking
4329 guix build}). The @command{guix gc --list-roots} command lists them.
4331 Prior to running @code{guix gc --collect-garbage} to make space, it is
4332 often useful to remove old generations from user profiles; that way, old
4333 package builds referenced by those generations can be reclaimed. This
4334 is achieved by running @code{guix package --delete-generations}
4335 (@pxref{Invoking guix package}).
4337 Our recommendation is to run a garbage collection periodically, or when
4338 you are short on disk space. For instance, to guarantee that at least
4339 5@tie{}GB are available on your disk, simply run:
4345 It is perfectly safe to run as a non-interactive periodic job
4346 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4347 Running @command{guix gc} with no arguments will collect as
4348 much garbage as it can, but that is often inconvenient: you may find
4349 yourself having to rebuild or re-download software that is ``dead'' from
4350 the GC viewpoint but that is necessary to build other pieces of
4351 software---e.g., the compiler tool chain.
4353 The @command{guix gc} command has three modes of operation: it can be
4354 used to garbage-collect any dead files (the default), to delete specific
4355 files (the @option{--delete} option), to print garbage-collector
4356 information, or for more advanced queries. The garbage collection
4357 options are as follows:
4360 @item --collect-garbage[=@var{min}]
4361 @itemx -C [@var{min}]
4362 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4363 sub-directories. This is the default operation when no option is
4366 When @var{min} is given, stop once @var{min} bytes have been collected.
4367 @var{min} may be a number of bytes, or it may include a unit as a
4368 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4369 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4371 When @var{min} is omitted, collect all the garbage.
4373 @item --free-space=@var{free}
4374 @itemx -F @var{free}
4375 Collect garbage until @var{free} space is available under
4376 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4377 as @code{500MiB}, as described above.
4379 When @var{free} or more is already available in @file{/gnu/store}, do
4380 nothing and exit immediately.
4382 @item --delete-generations[=@var{duration}]
4383 @itemx -d [@var{duration}]
4384 Before starting the garbage collection process, delete all the generations
4385 older than @var{duration}, for all the user profiles and home environment
4386 generations; when run as root, this
4387 applies to all the profiles @emph{of all the users}.
4389 For example, this command deletes all the generations of all your profiles
4390 that are older than 2 months (except generations that are current), and then
4391 proceeds to free space until at least 10 GiB are available:
4394 guix gc -d 2m -F 10G
4399 Attempt to delete all the store files and directories specified as
4400 arguments. This fails if some of the files are not in the store, or if
4401 they are still live.
4403 @item --list-failures
4404 List store items corresponding to cached build failures.
4406 This prints nothing unless the daemon was started with
4407 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4408 @option{--cache-failures}}).
4411 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4415 List store items in use by currently running processes. These store
4416 items are effectively considered GC roots: they cannot be deleted.
4418 @item --clear-failures
4419 Remove the specified store items from the failed-build cache.
4421 Again, this option only makes sense when the daemon is started with
4422 @option{--cache-failures}. Otherwise, it does nothing.
4425 Show the list of dead files and directories still present in the
4426 store---i.e., files and directories no longer reachable from any root.
4429 Show the list of live store files and directories.
4433 In addition, the references among existing store files can be queried:
4439 @cindex package dependencies
4440 List the references (respectively, the referrers) of store files given
4446 List the requisites of the store files passed as arguments. Requisites
4447 include the store files themselves, their references, and the references
4448 of these, recursively. In other words, the returned list is the
4449 @dfn{transitive closure} of the store files.
4451 @xref{Invoking guix size}, for a tool to profile the size of the closure
4452 of an element. @xref{Invoking guix graph}, for a tool to visualize
4453 the graph of references.
4457 Return the derivation(s) leading to the given store items
4458 (@pxref{Derivations}).
4460 For example, this command:
4463 guix gc --derivers $(guix package -I ^emacs$ | cut -f4)
4467 returns the @file{.drv} file(s) leading to the @code{emacs} package
4468 installed in your profile.
4470 Note that there may be zero matching @file{.drv} files, for instance
4471 because these files have been garbage-collected. There can also be more
4472 than one matching @file{.drv} due to fixed-output derivations.
4475 Lastly, the following options allow you to check the integrity of the
4476 store and to control disk usage.
4480 @item --verify[=@var{options}]
4481 @cindex integrity, of the store
4482 @cindex integrity checking
4483 Verify the integrity of the store.
4485 By default, make sure that all the store items marked as valid in the
4486 database of the daemon actually exist in @file{/gnu/store}.
4488 When provided, @var{options} must be a comma-separated list containing one
4489 or more of @code{contents} and @code{repair}.
4491 When passing @option{--verify=contents}, the daemon computes the
4492 content hash of each store item and compares it against its hash in the
4493 database. Hash mismatches are reported as data corruptions. Because it
4494 traverses @emph{all the files in the store}, this command can take a
4495 long time, especially on systems with a slow disk drive.
4497 @cindex repairing the store
4498 @cindex corruption, recovering from
4499 Using @option{--verify=repair} or @option{--verify=contents,repair}
4500 causes the daemon to try to repair corrupt store items by fetching
4501 substitutes for them (@pxref{Substitutes}). Because repairing is not
4502 atomic, and thus potentially dangerous, it is available only to the
4503 system administrator. A lightweight alternative, when you know exactly
4504 which items in the store are corrupt, is @command{guix build --repair}
4505 (@pxref{Invoking guix build}).
4508 @cindex deduplication
4509 Optimize the store by hard-linking identical files---this is
4510 @dfn{deduplication}.
4512 The daemon performs deduplication after each successful build or archive
4513 import, unless it was started with @option{--disable-deduplication}
4514 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4515 this option is primarily useful when the daemon was running with
4516 @option{--disable-deduplication}.
4520 @node Invoking guix pull
4521 @section Invoking @command{guix pull}
4523 @cindex upgrading Guix
4524 @cindex updating Guix
4525 @cindex @command{guix pull}
4527 @cindex security, @command{guix pull}
4528 @cindex authenticity, of code obtained with @command{guix pull}
4529 Packages are installed or upgraded to the latest version available in
4530 the distribution currently available on your local machine. To update
4531 that distribution, along with the Guix tools, you must run @command{guix
4532 pull}: the command downloads the latest Guix source code and package
4533 descriptions, and deploys it. Source code is downloaded from a
4534 @uref{https://git-scm.com, Git} repository, by default the official
4535 GNU@tie{}Guix repository, though this can be customized. @command{guix
4536 pull} ensures that the code it downloads is @emph{authentic} by
4537 verifying that commits are signed by Guix developers.
4539 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4540 (@pxref{Channels}) specified by one of the followings, in this order:
4544 the @option{--channels} option;
4546 the user's @file{~/.config/guix/channels.scm} file;
4548 the system-wide @file{/etc/guix/channels.scm} file;
4550 the built-in default channels specified in the @code{%default-channels}
4554 On completion, @command{guix package} will use packages and package
4555 versions from this just-retrieved copy of Guix. Not only that, but all
4556 the Guix commands and Scheme modules will also be taken from that latest
4557 version. New @command{guix} sub-commands added by the update also
4560 Any user can update their Guix copy using @command{guix pull}, and the
4561 effect is limited to the user who ran @command{guix pull}. For
4562 instance, when user @code{root} runs @command{guix pull}, this has no
4563 effect on the version of Guix that user @code{alice} sees, and vice
4566 The result of running @command{guix pull} is a @dfn{profile} available
4567 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4568 make sure to add it to the beginning of your search path so that you use
4569 the latest version, and similarly for the Info manual
4570 (@pxref{Documentation}):
4573 export PATH="$HOME/.config/guix/current/bin:$PATH"
4574 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4577 The @option{--list-generations} or @option{-l} option lists past generations
4578 produced by @command{guix pull}, along with details about their provenance:
4582 Generation 1 Jun 10 2018 00:18:18
4584 repository URL: https://git.savannah.gnu.org/git/guix.git
4585 branch: origin/master
4586 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4588 Generation 2 Jun 11 2018 11:02:49
4590 repository URL: https://git.savannah.gnu.org/git/guix.git
4591 branch: origin/master
4592 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4594 Generation 3 Jun 13 2018 23:31:07 (current)
4596 repository URL: https://git.savannah.gnu.org/git/guix.git
4597 branch: origin/master
4598 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4601 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4602 describe the current status of Guix.
4604 This @code{~/.config/guix/current} profile works exactly like the profiles
4605 created by @command{guix package} (@pxref{Invoking guix package}). That
4606 is, you can list generations, roll back to the previous
4607 generation---i.e., the previous Guix---and so on:
4610 $ guix pull --roll-back
4611 switched from generation 3 to 2
4612 $ guix pull --delete-generations=1
4613 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4616 You can also use @command{guix package} (@pxref{Invoking guix package})
4617 to manage the profile by naming it explicitly:
4619 $ guix package -p ~/.config/guix/current --roll-back
4620 switched from generation 3 to 2
4621 $ guix package -p ~/.config/guix/current --delete-generations=1
4622 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4625 The @command{guix pull} command is usually invoked with no arguments,
4626 but it supports the following options:
4629 @item --url=@var{url}
4630 @itemx --commit=@var{commit}
4631 @itemx --branch=@var{branch}
4632 Download code for the @code{guix} channel from the specified @var{url}, at the
4633 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4634 string), or @var{branch}.
4636 @cindex @file{channels.scm}, configuration file
4637 @cindex configuration file for channels
4638 These options are provided for convenience, but you can also specify your
4639 configuration in the @file{~/.config/guix/channels.scm} file or using the
4640 @option{--channels} option (see below).
4642 @item --channels=@var{file}
4643 @itemx -C @var{file}
4644 Read the list of channels from @var{file} instead of
4645 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4646 @var{file} must contain Scheme code that
4647 evaluates to a list of channel objects. @xref{Channels}, for more
4650 @cindex channel news
4653 Display news written by channel authors for their users for changes made
4654 since the previous generation (@pxref{Channels, Writing Channel News}).
4655 When @option{--details} is passed, additionally display new and upgraded
4658 You can view that information for previous generations with
4659 @command{guix pull -l}.
4661 @item --list-generations[=@var{pattern}]
4662 @itemx -l [@var{pattern}]
4663 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4664 is provided, the subset of generations that match @var{pattern}.
4665 The syntax of @var{pattern} is the same as with @code{guix package
4666 --list-generations} (@pxref{Invoking guix package}).
4668 By default, this prints information about the channels used in each
4669 revision as well as the corresponding news entries. If you pass
4670 @option{--details}, it will also print the list of packages added and
4671 upgraded in each generation compared to the previous one.
4674 Instruct @option{--list-generations} or @option{--news} to display more
4675 information about the differences between subsequent generations---see
4679 @cindex rolling back
4680 @cindex undoing transactions
4681 @cindex transactions, undoing
4682 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4683 undo the last transaction.
4685 @item --switch-generation=@var{pattern}
4686 @itemx -S @var{pattern}
4688 Switch to a particular generation defined by @var{pattern}.
4690 @var{pattern} may be either a generation number or a number prefixed
4691 with ``+'' or ``-''. The latter means: move forward/backward by a
4692 specified number of generations. For example, if you want to return to
4693 the latest generation after @option{--roll-back}, use
4694 @option{--switch-generation=+1}.
4696 @item --delete-generations[=@var{pattern}]
4697 @itemx -d [@var{pattern}]
4698 When @var{pattern} is omitted, delete all generations except the current
4701 This command accepts the same patterns as @option{--list-generations}.
4702 When @var{pattern} is specified, delete the matching generations. When
4703 @var{pattern} specifies a duration, generations @emph{older} than the
4704 specified duration match. For instance, @option{--delete-generations=1m}
4705 deletes generations that are more than one month old.
4707 If the current generation matches, it is @emph{not} deleted.
4709 Note that deleting generations prevents rolling back to them.
4710 Consequently, this command must be used with care.
4712 @xref{Invoking guix describe}, for a way to display information about the
4713 current generation only.
4715 @item --profile=@var{profile}
4716 @itemx -p @var{profile}
4717 Use @var{profile} instead of @file{~/.config/guix/current}.
4721 Show which channel commit(s) would be used and what would be built or
4722 substituted but do not actually do it.
4724 @item --allow-downgrades
4725 Allow pulling older or unrelated revisions of channels than those
4728 @cindex downgrade attacks, protection against
4729 By default, @command{guix pull} protects against so-called ``downgrade
4730 attacks'' whereby the Git repository of a channel would be reset to an
4731 earlier or unrelated revision of itself, potentially leading you to
4732 install older, known-vulnerable versions of software packages.
4735 Make sure you understand its security implications before using
4736 @option{--allow-downgrades}.
4739 @item --disable-authentication
4740 Allow pulling channel code without authenticating it.
4742 @cindex authentication, of channel code
4743 By default, @command{guix pull} authenticates code downloaded from
4744 channels by verifying that its commits are signed by authorized
4745 developers, and raises an error if this is not the case. This option
4746 instructs it to not perform any such verification.
4749 Make sure you understand its security implications before using
4750 @option{--disable-authentication}.
4753 @item --system=@var{system}
4754 @itemx -s @var{system}
4755 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4756 the system type of the build host.
4759 Use the bootstrap Guile to build the latest Guix. This option is only
4760 useful to Guix developers.
4763 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4764 repository and branch to pull from, as well as @emph{additional} repositories
4765 containing package modules that should be deployed. @xref{Channels}, for more
4768 In addition, @command{guix pull} supports all the common build options
4769 (@pxref{Common Build Options}).
4771 @node Invoking guix time-machine
4772 @section Invoking @command{guix time-machine}
4774 @cindex @command{guix time-machine}
4775 @cindex pinning, channels
4776 @cindex replicating Guix
4777 @cindex reproducibility, of Guix
4779 The @command{guix time-machine} command provides access to other
4780 revisions of Guix, for example to install older versions of packages,
4781 or to reproduce a computation in an identical environment. The revision
4782 of Guix to be used is defined by a commit or by a channel
4783 description file created by @command{guix describe}
4784 (@pxref{Invoking guix describe}).
4786 The general syntax is:
4789 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4792 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4793 @command{guix} command of the specified revision. The @var{options} that define
4794 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4797 @item --url=@var{url}
4798 @itemx --commit=@var{commit}
4799 @itemx --branch=@var{branch}
4800 Use the @code{guix} channel from the specified @var{url}, at the
4801 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4802 string), or @var{branch}.
4804 @item --channels=@var{file}
4805 @itemx -C @var{file}
4806 Read the list of channels from @var{file}. @var{file} must contain
4807 Scheme code that evaluates to a list of channel objects.
4808 @xref{Channels} for more information.
4811 As for @command{guix pull}, the absence of any options means that the
4812 latest commit on the master branch will be used. The command
4815 guix time-machine -- build hello
4818 will thus build the package @code{hello} as defined in the master branch,
4819 which is in general a newer revision of Guix than you have installed.
4820 Time travel works in both directions!
4822 Note that @command{guix time-machine} can trigger builds of channels and
4823 their dependencies, and these are controlled by the standard build
4824 options (@pxref{Common Build Options}).
4829 @c TODO: Remove this once we're more confident about API stability.
4831 The functionality described here is a ``technology preview'' as of version
4832 @value{VERSION}. As such, the interface is subject to change.
4836 @cindex composition of Guix revisions
4837 Sometimes you might need to mix packages from the revision of Guix you're
4838 currently running with packages available in a different revision of Guix.
4839 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4840 revisions in arbitrary ways.
4842 @cindex inferior packages
4843 Technically, an ``inferior'' is essentially a separate Guix process connected
4844 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4845 @code{(guix inferior)} module allows you to create inferiors and to
4846 communicate with them. It also provides a high-level interface to browse and
4847 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4849 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4850 to interact with a separate revision of Guix. For example, let's assume you
4851 want to install in your profile the current @code{guile} package, along with
4852 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4853 because the newer @code{guile-json} has an incompatible API and you want to
4854 run your code against the old API@. To do that, you could write a manifest for
4855 use by @code{guix package --manifest} (@pxref{Writing Manifests}); in that
4856 manifest, you would create an inferior for that old Guix revision you care
4857 about, and you would look up the @code{guile-json} package in the inferior:
4860 (use-modules (guix inferior) (guix channels)
4861 (srfi srfi-1)) ;for 'first'
4864 ;; This is the old revision from which we want to
4865 ;; extract guile-json.
4868 (url "https://git.savannah.gnu.org/git/guix.git")
4870 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4873 ;; An inferior representing the above revision.
4874 (inferior-for-channels channels))
4876 ;; Now create a manifest with the current "guile" package
4877 ;; and the old "guile-json" package.
4879 (list (first (lookup-inferior-packages inferior "guile-json"))
4880 (specification->package "guile")))
4883 On its first run, @command{guix package --manifest} might have to build the
4884 channel you specified before it can create the inferior; subsequent runs will
4885 be much faster because the Guix revision will be cached.
4887 The @code{(guix inferior)} module provides the following procedures to open an
4890 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4891 [#:cache-directory] [#:ttl]
4892 Return an inferior for @var{channels}, a list of channels. Use the cache at
4893 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4894 This procedure opens a new connection to the build daemon.
4896 As a side effect, this procedure may build or substitute binaries for
4897 @var{channels}, which can take time.
4900 @deffn {Scheme Procedure} open-inferior @var{directory} @
4901 [#:command "bin/guix"]
4902 Open the inferior Guix in @var{directory}, running
4903 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4904 the inferior could not be launched.
4907 @cindex inferior packages
4908 The procedures listed below allow you to obtain and manipulate inferior
4911 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4912 Return the list of packages known to @var{inferior}.
4915 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4917 Return the sorted list of inferior packages matching @var{name} in
4918 @var{inferior}, with highest version numbers first. If @var{version} is true,
4919 return only packages with a version number prefixed by @var{version}.
4922 @deffn {Scheme Procedure} inferior-package? @var{obj}
4923 Return true if @var{obj} is an inferior package.
4926 @deffn {Scheme Procedure} inferior-package-name @var{package}
4927 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4928 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4929 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4930 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4931 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4932 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4933 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4934 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4935 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4936 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4937 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4938 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4939 These procedures are the counterpart of package record accessors
4940 (@pxref{package Reference}). Most of them work by querying the inferior
4941 @var{package} comes from, so the inferior must still be live when you call
4945 Inferior packages can be used transparently like any other package or
4946 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4947 transparently handled by the @code{packages->manifest} procedure, which is
4948 commonly used in manifests (@pxref{Invoking guix package, the
4949 @option{--manifest} option of @command{guix package}}). Thus you can insert
4950 an inferior package pretty much anywhere you would insert a regular package:
4951 in manifests, in the @code{packages} field of your @code{operating-system}
4952 declaration, and so on.
4954 @node Invoking guix describe
4955 @section Invoking @command{guix describe}
4957 @cindex reproducibility
4958 @cindex replicating Guix
4959 @cindex @command{guix describe}
4960 Often you may want to answer questions like: ``Which revision of Guix am I
4961 using?'' or ``Which channels am I using?'' This is useful information in many
4962 situations: if you want to @emph{replicate} an environment on a different
4963 machine or user account, if you want to report a bug or to determine what
4964 change in the channels you are using caused it, or if you want to record your
4965 system state for reproducibility purposes. The @command{guix describe}
4966 command answers these questions.
4968 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4969 displays the channel(s) that it was built from, including their repository URL
4970 and commit IDs (@pxref{Channels}):
4974 Generation 10 Sep 03 2018 17:32:44 (current)
4976 repository URL: https://git.savannah.gnu.org/git/guix.git
4978 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4981 If you're familiar with the Git version control system, this is similar in
4982 spirit to @command{git describe}; the output is also similar to that of
4983 @command{guix pull --list-generations}, but limited to the current generation
4984 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4985 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4986 information is all it takes to describe the revision of Guix you're using, and
4987 also to replicate it.
4989 To make it easier to replicate Guix, @command{guix describe} can also be asked
4990 to return a list of channels instead of the human-readable description above:
4993 $ guix describe -f channels
4996 (url "https://git.savannah.gnu.org/git/guix.git")
4998 "e0fa68c7718fffd33d81af415279d6ddb518f727")
5000 (make-channel-introduction
5001 "9edb3f66fd807b096b48283debdcddccfea34bad"
5002 (openpgp-fingerprint
5003 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
5007 You can save this to a file and feed it to @command{guix pull -C} on some
5008 other machine or at a later point in time, which will instantiate @emph{this
5009 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
5010 From there on, since you're able to deploy the same revision of Guix, you can
5011 just as well @emph{replicate a complete software environment}. We humbly
5012 think that this is @emph{awesome}, and we hope you'll like it too!
5014 The details of the options supported by @command{guix describe} are as
5018 @item --format=@var{format}
5019 @itemx -f @var{format}
5020 Produce output in the specified @var{format}, one of:
5024 produce human-readable output;
5026 produce a list of channel specifications that can be passed to @command{guix
5027 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
5029 @item channels-sans-intro
5030 like @code{channels}, but omit the @code{introduction} field; use it to
5031 produce a channel specification suitable for Guix version 1.1.0 or
5032 earlier---the @code{introduction} field has to do with channel
5033 authentication (@pxref{Channels, Channel Authentication}) and is not
5034 supported by these older versions;
5037 produce a list of channel specifications in JSON format;
5039 produce a list of channel specifications in Recutils format.
5042 @item --list-formats
5043 Display available formats for @option{--format} option.
5045 @item --profile=@var{profile}
5046 @itemx -p @var{profile}
5047 Display information about @var{profile}.
5050 @node Invoking guix archive
5051 @section Invoking @command{guix archive}
5053 @cindex @command{guix archive}
5055 @cindex exporting files from the store
5056 @cindex importing files to the store
5057 The @command{guix archive} command allows users to @dfn{export} files
5058 from the store into a single archive, and to later @dfn{import} them on
5059 a machine that runs Guix.
5060 In particular, it allows store files to be transferred from one machine
5061 to the store on another machine.
5064 If you're looking for a way to produce archives in a format suitable for
5065 tools other than Guix, @pxref{Invoking guix pack}.
5068 @cindex exporting store items
5069 To export store files as an archive to standard output, run:
5072 guix archive --export @var{options} @var{specifications}...
5075 @var{specifications} may be either store file names or package
5076 specifications, as for @command{guix package} (@pxref{Invoking guix
5077 package}). For instance, the following command creates an archive
5078 containing the @code{gui} output of the @code{git} package and the main
5079 output of @code{emacs}:
5082 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
5085 If the specified packages are not built yet, @command{guix archive}
5086 automatically builds them. The build process may be controlled with the
5087 common build options (@pxref{Common Build Options}).
5089 To transfer the @code{emacs} package to a machine connected over SSH,
5093 guix archive --export -r emacs | ssh the-machine guix archive --import
5097 Similarly, a complete user profile may be transferred from one machine
5098 to another like this:
5101 guix archive --export -r $(readlink -f ~/.guix-profile) | \
5102 ssh the-machine guix archive --import
5106 However, note that, in both examples, all of @code{emacs} and the
5107 profile as well as all of their dependencies are transferred (due to
5108 @option{-r}), regardless of what is already available in the store on
5109 the target machine. The @option{--missing} option can help figure out
5110 which items are missing from the target store. The @command{guix copy}
5111 command simplifies and optimizes this whole process, so this is probably
5112 what you should use in this case (@pxref{Invoking guix copy}).
5114 @cindex nar, archive format
5115 @cindex normalized archive (nar)
5116 @cindex nar bundle, archive format
5117 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
5118 format (described below), and the output of @command{guix archive
5119 --export} (and input of @command{guix archive --import}) is a @dfn{nar
5123 comparable in spirit to `tar', but with differences
5124 that make it more appropriate for our purposes. First, rather than
5125 recording all Unix metadata for each file, the nar format only mentions
5126 the file type (regular, directory, or symbolic link); Unix permissions
5127 and owner/group are dismissed. Second, the order in which directory
5128 entries are stored always follows the order of file names according to
5129 the C locale collation order. This makes archive production fully
5132 That nar bundle format is essentially the concatenation of zero or more
5133 nars along with metadata for each store item it contains: its file name,
5134 references, corresponding derivation, and a digital signature.
5136 When exporting, the daemon digitally signs the contents of the archive,
5137 and that digital signature is appended. When importing, the daemon
5138 verifies the signature and rejects the import in case of an invalid
5139 signature or if the signing key is not authorized.
5140 @c FIXME: Add xref to daemon doc about signatures.
5142 The main options are:
5146 Export the specified store files or packages (see below). Write the
5147 resulting archive to the standard output.
5149 Dependencies are @emph{not} included in the output, unless
5150 @option{--recursive} is passed.
5154 When combined with @option{--export}, this instructs @command{guix archive}
5155 to include dependencies of the given items in the archive. Thus, the
5156 resulting archive is self-contained: it contains the closure of the
5157 exported store items.
5160 Read an archive from the standard input, and import the files listed
5161 therein into the store. Abort if the archive has an invalid digital
5162 signature, or if it is signed by a public key not among the authorized
5163 keys (see @option{--authorize} below).
5166 Read a list of store file names from the standard input, one per line,
5167 and write on the standard output the subset of these files missing from
5170 @item --generate-key[=@var{parameters}]
5171 @cindex signing, archives
5172 Generate a new key pair for the daemon. This is a prerequisite before
5173 archives can be exported with @option{--export}. This
5174 operation is usually instantaneous but it can take time if the system's
5175 entropy pool needs to be refilled. On Guix System,
5176 @code{guix-service-type} takes care of generating this key pair the
5179 The generated key pair is typically stored under @file{/etc/guix}, in
5180 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
5181 key, which must be kept secret). When @var{parameters} is omitted,
5182 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
5183 versions before 1.6.0, it is a 4096-bit RSA key.
5184 Alternatively, @var{parameters} can specify
5185 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
5186 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
5187 Libgcrypt Reference Manual}).
5190 @cindex authorizing, archives
5191 Authorize imports signed by the public key passed on standard input.
5192 The public key must be in ``s-expression advanced format''---i.e., the
5193 same format as the @file{signing-key.pub} file.
5195 The list of authorized keys is kept in the human-editable file
5196 @file{/etc/guix/acl}. The file contains
5197 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
5198 s-expressions''} and is structured as an access-control list in the
5199 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
5202 @item --extract=@var{directory}
5203 @itemx -x @var{directory}
5204 Read a single-item archive as served by substitute servers
5205 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
5206 low-level operation needed in only very narrow use cases; see below.
5208 For example, the following command extracts the substitute for Emacs
5209 served by @code{@value{SUBSTITUTE-SERVER-1}} to @file{/tmp/emacs}:
5213 https://@value{SUBSTITUTE-SERVER-1}/nar/gzip/@dots{}-emacs-24.5 \
5214 | gunzip | guix archive -x /tmp/emacs
5217 Single-item archives are different from multiple-item archives produced
5218 by @command{guix archive --export}; they contain a single store item,
5219 and they do @emph{not} embed a signature. Thus this operation does
5220 @emph{no} signature verification and its output should be considered
5223 The primary purpose of this operation is to facilitate inspection of
5224 archive contents coming from possibly untrusted substitute servers
5225 (@pxref{Invoking guix challenge}).
5229 Read a single-item archive as served by substitute servers
5230 (@pxref{Substitutes}) and print the list of files it contains, as in
5235 https://@value{SUBSTITUTE-SERVER-1}/nar/lzip/@dots{}-emacs-26.3 \
5236 | lzip -d | guix archive -t
5241 @c *********************************************************************
5246 @cindex @file{channels.scm}, configuration file
5247 @cindex configuration file for channels
5248 @cindex @command{guix pull}, configuration file
5249 @cindex configuration of @command{guix pull}
5250 Guix and its package collection are updated by running @command{guix pull}
5251 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
5252 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
5253 customized by defining @dfn{channels} in the
5254 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
5255 of a Git repository to be deployed, and @command{guix pull} can be instructed
5256 to pull from one or more channels. In other words, channels can be used
5257 to @emph{customize} and to @emph{extend} Guix, as we will see below.
5258 Guix is able to take into account security concerns and deal with authenticated
5262 * Specifying Additional Channels:: Extending the package collection.
5263 * Using a Custom Guix Channel:: Using a customized Guix.
5264 * Replicating Guix:: Running the @emph{exact same} Guix.
5265 * Channel Authentication:: How Guix verifies what it fetches.
5266 * Channels with Substitutes:: Using channels with available substitutes.
5267 * Creating a Channel:: How to write your custom channel.
5268 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
5269 * Declaring Channel Dependencies:: How to depend on other channels.
5270 * Specifying Channel Authorizations:: Defining channel authors authorizations.
5271 * Primary URL:: Distinguishing mirror to original.
5272 * Writing Channel News:: Communicating information to channel's users.
5275 @node Specifying Additional Channels
5276 @section Specifying Additional Channels
5278 @cindex extending the package collection (channels)
5279 @cindex variant packages (channels)
5280 You can specify @emph{additional channels} to pull from. To use a channel, write
5281 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
5282 @emph{in addition} to the default Guix channel(s):
5284 @vindex %default-channels
5286 ;; Add variant packages to those Guix provides.
5288 (name 'variant-packages)
5289 (url "https://example.org/variant-packages.git"))
5294 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
5295 add a channel the list of channels that the variable @code{%default-channels}
5296 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
5297 Manual}). With this file in place, @command{guix pull} builds not only Guix
5298 but also the package modules from your own repository. The result in
5299 @file{~/.config/guix/current} is the union of Guix with your own package
5304 Generation 19 Aug 27 2018 16:20:48
5306 repository URL: https://git.savannah.gnu.org/git/guix.git
5308 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
5309 variant-packages dd3df5e
5310 repository URL: https://example.org/variant-packages.git
5312 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
5316 The output of @command{guix describe} above shows that we're now running
5317 Generation@tie{}19 and that it includes
5318 both Guix and packages from the @code{variant-personal-packages} channel
5319 (@pxref{Invoking guix describe}).
5321 @node Using a Custom Guix Channel
5322 @section Using a Custom Guix Channel
5324 The channel called @code{guix} specifies where Guix itself---its command-line
5325 tools as well as its package collection---should be downloaded. For instance,
5326 suppose you want to update from another copy of the Guix repository at
5327 @code{example.org}, and specifically the @code{super-hacks} branch, you can
5328 write in @code{~/.config/guix/channels.scm} this specification:
5331 ;; Tell 'guix pull' to use another repo.
5334 (url "https://example.org/another-guix.git")
5335 (branch "super-hacks")))
5339 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
5340 branch of the repository at @code{example.org}. The authentication concern is
5341 addressed below (@pxref{Channel Authentication}).
5343 @node Replicating Guix
5344 @section Replicating Guix
5346 @cindex pinning, channels
5347 @cindex replicating Guix
5348 @cindex reproducibility, of Guix
5349 The @command{guix describe} command shows precisely which commits were
5350 used to build the instance of Guix we're using (@pxref{Invoking guix
5351 describe}). We can replicate this instance on another machine or at a
5352 different point in time by providing a channel specification ``pinned''
5353 to these commits that looks like this:
5356 ;; Deploy specific commits of my channels of interest.
5359 (url "https://git.savannah.gnu.org/git/guix.git")
5360 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5362 (name 'variant-packages)
5363 (url "https://example.org/variant-packages.git")
5364 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5367 To obtain this pinned channel specification, the easiest way is to run
5368 @command{guix describe} and to save its output in the @code{channels}
5369 format in a file, like so:
5372 guix describe -f channels > channels.scm
5375 The resulting @file{channels.scm} file can be passed to the @option{-C}
5376 option of @command{guix pull} (@pxref{Invoking guix pull}) or
5377 @command{guix time-machine} (@pxref{Invoking guix time-machine}), as in
5381 guix time-machine -C channels.scm -- shell python -- python3
5384 Given the @file{channels.scm} file, the command above will always fetch
5385 the @emph{exact same Guix instance}, then use that instance to run the
5386 exact same Python (@pxref{Invoking guix shell}). On any machine, at any
5387 time, it ends up running the exact same binaries, bit for bit.
5390 Pinned channels address a problem similar to ``lock files'' as
5391 implemented by some deployment tools---they let you pin and reproduce a
5392 set of packages. In the case of Guix though, you are effectively
5393 pinning the entire package set as defined at the given channel commits;
5394 in fact, you are pinning all of Guix, including its core modules and
5395 command-line tools. You're also getting strong guarantees that you are,
5396 indeed, obtaining the exact same software.
5398 This gives you super powers, allowing you to track the provenance of binary
5399 artifacts with very fine grain, and to reproduce software environments at
5400 will---some sort of ``meta reproducibility'' capabilities, if you will.
5401 @xref{Inferiors}, for another way to take advantage of these super powers.
5403 @node Channel Authentication
5404 @section Channel Authentication
5406 @anchor{channel-authentication}
5407 @cindex authentication, of channel code
5408 The @command{guix pull} and @command{guix time-machine} commands
5409 @dfn{authenticate} the code retrieved from channels: they make sure each
5410 commit that is fetched is signed by an authorized developer. The goal
5411 is to protect from unauthorized modifications to the channel that would
5412 lead users to run malicious code.
5414 As a user, you must provide a @dfn{channel introduction} in your
5415 channels file so that Guix knows how to authenticate its first commit.
5416 A channel specification, including its introduction, looks something
5421 (name 'some-channel)
5422 (url "https://example.org/some-channel.git")
5424 (make-channel-introduction
5425 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5426 (openpgp-fingerprint
5427 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5430 The specification above shows the name and URL of the channel. The call
5431 to @code{make-channel-introduction} above specifies that authentication
5432 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5433 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5435 For the main channel, called @code{guix}, you automatically get that
5436 information from your Guix installation. For other channels, include
5437 the channel introduction provided by the channel authors in your
5438 @file{channels.scm} file. Make sure you retrieve the channel
5439 introduction from a trusted source since that is the root of your trust.
5441 If you're curious about the authentication mechanics, read on!
5443 @node Channels with Substitutes
5444 @section Channels with Substitutes
5446 When running @command{guix pull}, Guix will first compile the
5447 definitions of every available package. This is an expensive operation
5448 for which substitutes (@pxref{Substitutes}) may be available. The
5449 following snippet in @file{channels.scm} will ensure that @command{guix
5450 pull} uses the latest commit with available substitutes for the package
5451 definitions: this is done by querying the continuous integration
5452 server at @url{https://ci.guix.gnu.org}.
5455 (use-modules (guix ci))
5457 (list (channel-with-substitutes-available
5458 %default-guix-channel
5459 "https://ci.guix.gnu.org"))
5462 Note that this does not mean that all the packages that you will
5463 install after running @command{guix pull} will have available
5464 substitutes. It only ensures that @command{guix pull} will not try to
5465 compile package definitions. This is particularly useful when using
5466 machines with limited resources.
5468 @node Creating a Channel
5469 @section Creating a Channel
5471 @cindex personal packages (channels)
5472 @cindex channels, for personal packages
5473 Let's say you have a bunch of custom package variants or personal packages
5474 that you think would make little sense to contribute to the Guix project, but
5475 would like to have these packages transparently available to you at the
5476 command line. You would first write modules containing those package
5477 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5478 then you and anyone else can use it as an additional channel to get packages
5481 @c What follows stems from discussions at
5482 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5483 @c earlier discussions on guix-devel@gnu.org.
5485 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5486 publish your personal channel to the world, we would like to share a few words
5491 Before publishing a channel, please consider contributing your package
5492 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5493 to free software of all sorts, and packages in Guix proper are readily
5494 available to all Guix users and benefit from the project's quality assurance
5498 When you maintain package definitions outside Guix, we, Guix developers,
5499 consider that @emph{the compatibility burden is on you}. Remember that
5500 package modules and package definitions are just Scheme code that uses various
5501 programming interfaces (APIs). We want to remain free to change these APIs to
5502 keep improving Guix, possibly in ways that break your channel. We never
5503 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5507 Corollary: if you're using an external channel and that channel breaks, please
5508 @emph{report the issue to the channel authors}, not to the Guix project.
5511 You've been warned! Having said this, we believe external channels are a
5512 practical way to exert your freedom to augment Guix' package collection and to
5513 share your improvements, which are basic tenets of
5514 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5515 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5518 To create a channel, create a Git repository containing your own package
5519 modules and make it available. The repository can contain anything, but a
5520 useful channel will contain Guile modules that export packages. Once you
5521 start using a channel, Guix will behave as if the root directory of that
5522 channel's Git repository has been added to the Guile load path (@pxref{Load
5523 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5524 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5525 module, then the module will be available under the name @code{(my-packages
5526 my-tools)}, and you will be able to use it like any other module
5527 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5529 As a channel author, consider bundling authentication material with your
5530 channel so that users can authenticate it. @xref{Channel
5531 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5535 @node Package Modules in a Sub-directory
5536 @section Package Modules in a Sub-directory
5538 @cindex subdirectory, channels
5539 As a channel author, you may want to keep your channel modules in a
5540 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5541 add a meta-data file @file{.guix-channel} that contains:
5549 @node Declaring Channel Dependencies
5550 @section Declaring Channel Dependencies
5552 @cindex dependencies, channels
5553 @cindex meta-data, channels
5554 Channel authors may decide to augment a package collection provided by other
5555 channels. They can declare their channel to be dependent on other channels in
5556 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5557 the channel repository.
5559 The meta-data file should contain a simple S-expression like this:
5566 (name some-collection)
5567 (url "https://example.org/first-collection.git")
5569 ;; The 'introduction' bit below is optional: you would
5570 ;; provide it for dependencies that can be authenticated.
5572 (channel-introduction
5574 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5575 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5577 (name some-other-collection)
5578 (url "https://example.org/second-collection.git")
5579 (branch "testing"))))
5582 In the above example this channel is declared to depend on two other channels,
5583 which will both be fetched automatically. The modules provided by the channel
5584 will be compiled in an environment where the modules of all these declared
5585 channels are available.
5587 For the sake of reliability and maintainability, you should avoid dependencies
5588 on channels that you don't control, and you should aim to keep the number of
5589 dependencies to a minimum.
5591 @node Specifying Channel Authorizations
5592 @section Specifying Channel Authorizations
5594 @cindex channel authorizations
5595 @anchor{channel-authorizations}
5596 As we saw above, Guix ensures the source code it pulls from channels
5597 comes from authorized developers. As a channel author, you need to
5598 specify the list of authorized developers in the
5599 @file{.guix-authorizations} file in the channel's Git repository. The
5600 authentication rule is simple: each commit must be signed by a key
5601 listed in the @file{.guix-authorizations} file of its parent
5602 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5603 (DAG). Each commit can have zero or more parents; ``regular'' commits
5604 have one parent and merge commits have two parent commits. Read
5605 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5606 for Computer Scientists}} for a great overview.} The
5607 @file{.guix-authorizations} file looks like this:
5610 ;; Example '.guix-authorizations' file.
5613 (version 0) ;current file format version
5615 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5617 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5619 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5623 Each fingerprint is followed by optional key/value pairs, as in the
5624 example above. Currently these key/value pairs are ignored.
5626 This authentication rule creates a chicken-and-egg issue: how do we
5627 authenticate the first commit? Related to that: how do we deal with
5628 channels whose repository history contains unsigned commits and lack
5629 @file{.guix-authorizations}? And how do we fork existing channels?
5631 @cindex channel introduction
5632 Channel introductions answer these questions by describing the first
5633 commit of a channel that should be authenticated. The first time a
5634 channel is fetched with @command{guix pull} or @command{guix
5635 time-machine}, the command looks up the introductory commit and verifies
5636 that it is signed by the specified OpenPGP key. From then on, it
5637 authenticates commits according to the rule above. Authentication fails
5638 if the target commit is neither a descendant nor an ancestor of the
5639 introductory commit.
5641 Additionally, your channel must provide all the OpenPGP keys that were
5642 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5643 files, which can be either binary or ``ASCII-armored''. By default,
5644 those @file{.key} files are searched for in the branch named
5645 @code{keyring} but you can specify a different branch name in
5646 @code{.guix-channel} like so:
5651 (keyring-reference "my-keyring-branch"))
5654 To summarize, as the author of a channel, there are three things you have
5655 to do to allow users to authenticate your code:
5659 Export the OpenPGP keys of past and present committers with @command{gpg
5660 --export} and store them in @file{.key} files, by default in a branch
5661 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5664 Introduce an initial @file{.guix-authorizations} in the channel's
5665 repository. Do that in a signed commit (@pxref{Commit Access}, for
5666 information on how to sign Git commits.)
5669 Advertise the channel introduction, for instance on your channel's web
5670 page. The channel introduction, as we saw above, is the commit/key
5671 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5672 the fingerprint of the OpenPGP used to sign it.
5675 Before pushing to your public Git repository, you can run @command{guix
5676 git-authenticate} to verify that you did sign all the commits you are
5677 about to push with an authorized key:
5680 guix git authenticate @var{commit} @var{signer}
5684 where @var{commit} and @var{signer} are your channel introduction.
5685 @xref{Invoking guix git authenticate}, for details.
5687 Publishing a signed channel requires discipline: any mistake, such as an
5688 unsigned commit or a commit signed by an unauthorized key, will prevent
5689 users from pulling from your channel---well, that's the whole point of
5690 authentication! Pay attention to merges in particular: merge commits
5691 are considered authentic if and only if they are signed by a key present
5692 in the @file{.guix-authorizations} file of @emph{both} branches.
5695 @section Primary URL
5697 @cindex primary URL, channels
5698 Channel authors can indicate the primary URL of their channel's Git
5699 repository in the @file{.guix-channel} file, like so:
5704 (url "https://example.org/guix.git"))
5707 This allows @command{guix pull} to determine whether it is pulling code
5708 from a mirror of the channel; when that is the case, it warns the user
5709 that the mirror might be stale and displays the primary URL@. That way,
5710 users cannot be tricked into fetching code from a stale mirror that does
5711 not receive security updates.
5713 This feature only makes sense for authenticated repositories, such as
5714 the official @code{guix} channel, for which @command{guix pull} ensures
5715 the code it fetches is authentic.
5717 @node Writing Channel News
5718 @section Writing Channel News
5720 @cindex news, for channels
5721 Channel authors may occasionally want to communicate to their users
5722 information about important changes in the channel. You'd send them all
5723 an email, but that's not convenient.
5725 Instead, channels can provide a @dfn{news file}; when the channel users
5726 run @command{guix pull}, that news file is automatically read and
5727 @command{guix pull --news} can display the announcements that correspond
5728 to the new commits that have been pulled, if any.
5730 To do that, channel authors must first declare the name of the news file
5731 in their @file{.guix-channel} file:
5736 (news-file "etc/news.txt"))
5739 The news file itself, @file{etc/news.txt} in this example, must look
5740 something like this:
5745 (entry (tag "the-bug-fix")
5746 (title (en "Fixed terrible bug")
5748 (body (en "@@emph@{Good news@}! It's fixed!")
5749 (eo "Certe ĝi pli bone funkcias nun!")))
5750 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5751 (title (en "Added a great package")
5752 (ca "Què vol dir guix?"))
5753 (body (en "Don't miss the @@code@{hello@} package!"))))
5756 While the news file is using the Scheme syntax, avoid naming it with a
5757 @file{.scm} extension or else it will get picked up when building the
5758 channel and yield an error since it is not a valid module.
5759 Alternatively, you can move the channel module to a subdirectory and
5760 store the news file in another directory.
5762 The file consists of a list of @dfn{news entries}. Each entry is
5763 associated with a commit or tag: it describes changes made in this
5764 commit, possibly in preceding commits as well. Users see entries only
5765 the first time they obtain the commit the entry refers to.
5767 The @code{title} field should be a one-line summary while @code{body}
5768 can be arbitrarily long, and both can contain Texinfo markup
5769 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5770 a list of language tag/message tuples, which allows @command{guix pull}
5771 to display news in the language that corresponds to the user's locale.
5773 If you want to translate news using a gettext-based workflow, you can
5774 extract translatable strings with @command{xgettext} (@pxref{xgettext
5775 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5776 you write news entries in English first, the command below creates a PO
5777 file containing the strings to translate:
5780 xgettext -o news.po -l scheme -ken etc/news.txt
5783 To sum up, yes, you could use your channel as a blog. But beware, this
5784 is @emph{not quite} what your users might expect.
5786 @c *********************************************************************
5788 @chapter Development
5790 @cindex software development
5791 If you are a software developer, Guix provides tools that you should find
5792 helpful---independently of the language you're developing in. This is what
5793 this chapter is about.
5795 The @command{guix shell} command provides a convenient way to set up
5796 one-off software environments, be it for development purposes or to run
5797 a command without installing it in your profile. The @command{guix
5798 pack} command allows you to create @dfn{application bundles} that can be
5799 easily distributed to users who do not run Guix.
5802 * Invoking guix shell:: Spawning one-off software environments.
5803 * Invoking guix environment:: Setting up development environments.
5804 * Invoking guix pack:: Creating software bundles.
5805 * The GCC toolchain:: Working with languages supported by GCC.
5806 * Invoking guix git authenticate:: Authenticating Git repositories.
5809 @node Invoking guix shell
5810 @section Invoking @command{guix shell}
5812 @cindex reproducible build environments
5813 @cindex development environments
5814 @cindex @command{guix environment}
5815 @cindex @command{guix shell}
5816 @cindex environment, package build environment
5817 The purpose of @command{guix shell} is to make it easy to create one-off
5818 software environments, without changing one's profile. It is typically
5819 used to create development environments; it is also a convenient way to
5820 run applications without ``polluting'' your profile.
5823 The @command{guix shell} command was recently introduced to supersede
5824 @command{guix environment} (@pxref{Invoking guix environment}). If you
5825 are familiar with @command{guix environment}, you will notice that it is
5826 similar but also---we hope!---more convenient.
5829 The general syntax is:
5832 guix shell [@var{options}] [@var{package}@dots{}]
5835 The following example creates an environment containing Python and NumPy,
5836 building or downloading any missing package, and runs the
5837 @command{python3} command in that environment:
5840 guix shell python python-numpy -- python3
5843 Development environments can be created as in the example below, which
5844 spawns an interactive shell containing all the dependencies and
5845 environment variables needed to work on Inkscape:
5848 guix shell --development inkscape
5851 Exiting the shell places the user back in the original environment
5852 before @command{guix shell} was invoked. The next garbage collection
5853 (@pxref{Invoking guix gc}) may clean up packages that were installed in
5854 the environment and that are no longer used outside of it.
5856 As an added convenience, @command{guix shell} will try to do what you
5857 mean when it is invoked interactively without any other arguments
5864 If it finds a @file{manifest.scm} in the current working directory or
5865 any of its parents, it uses this manifest as though it was given via @code{--manifest}.
5866 Likewise, if it finds a @file{guix.scm} in the same directories, it uses
5867 it to build a development profile as though both @code{--development}
5868 and @code{--file} were present.
5869 In either case, the file will only be loaded if the directory it
5870 resides in is listed in
5871 @file{~/.config/guix/shell-authorized-directories}.
5872 This provides an easy way to define, share, and enter development
5875 By default, the shell session or command runs in an @emph{augmented}
5876 environment, where the new packages are added to search path environment
5877 variables such as @code{PATH}. You can, instead, choose to create an
5878 @emph{isolated} environment containing nothing but the packages you
5879 asked for. Passing the @option{--pure} option clears environment
5880 variable definitions found in the parent environment@footnote{Be sure to
5881 use the @option{--check} option the first time you use @command{guix
5882 shell} interactively to make sure the shell does not undo the effect of
5883 @option{--pure}.}; passing @option{--container} goes one step further by
5884 spawning a @dfn{container} isolated from the rest of the system:
5887 guix shell --container emacs gcc-toolchain
5890 The command above spawns an interactive shell in a container where
5891 nothing but @code{emacs}, @code{gcc-toolchain}, and their dependencies
5892 is available. The container lacks network access and shares no files
5893 other than the current working directory with the surrounding
5894 environment. This is useful to prevent access to system-wide resources
5895 such as @file{/usr/bin} on foreign distros.
5897 This @option{--container} option can also prove useful if you wish to
5898 run a security-sensitive application, such as a web browser, in an
5899 isolated environment. For example, the command below launches
5900 Ungoogled-Chromium in an isolated environment, this time sharing network
5901 access with the host and preserving its @code{DISPLAY} environment
5902 variable, but without even sharing the current directory:
5905 guix shell --container --network --no-cwd ungoogled-chromium \
5906 --preserve='^DISPLAY$' -- chromium
5909 @vindex GUIX_ENVIRONMENT
5910 @command{guix shell} defines the @env{GUIX_ENVIRONMENT}
5911 variable in the shell it spawns; its value is the file name of the
5912 profile of this environment. This allows users to, say, define a
5913 specific prompt for development environments in their @file{.bashrc}
5914 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5917 if [ -n "$GUIX_ENVIRONMENT" ]
5919 export PS1="\u@@\h \w [dev]\$ "
5924 ...@: or to browse the profile:
5927 $ ls "$GUIX_ENVIRONMENT/bin"
5930 The available options are summarized below.
5934 Set up the environment and check whether the shell would clobber
5935 environment variables. It's a good idea to use this option the first
5936 time you run @command{guix shell} for an interactive session to make
5937 sure your setup is correct.
5939 For example, if the shell modifies the @env{PATH} environment variable,
5940 report it since you would get a different environment than what you
5943 Such problems usually indicate that the shell startup files are
5944 unexpectedly modifying those environment variables. For example, if you
5945 are using Bash, make sure that environment variables are set or modified
5946 in @file{~/.bash_profile} and @emph{not} in @file{~/.bashrc}---the
5947 former is sourced only by log-in shells. @xref{Bash Startup Files,,,
5948 bash, The GNU Bash Reference Manual}, for details on Bash start-up
5951 @anchor{shell-development-option}
5954 Cause @command{guix shell} to include in the environment the
5955 dependencies of the following package rather than the package itself.
5956 This can be combined with other packages. For instance, the command
5957 below starts an interactive shell containing the build-time dependencies
5958 of GNU@tie{}Guile, plus Autoconf, Automake, and Libtool:
5961 guix shell -D guile autoconf automake libtool
5964 @item --expression=@var{expr}
5965 @itemx -e @var{expr}
5966 Create an environment for the package or list of packages that
5967 @var{expr} evaluates to.
5969 For example, running:
5972 guix shell -D -e '(@@ (gnu packages maths) petsc-openmpi)'
5975 starts a shell with the environment for this specific variant of the
5981 guix shell -e '(@@ (gnu) %base-packages)'
5984 starts a shell with all the base system packages available.
5986 The above commands only use the default output of the given packages.
5987 To select other outputs, two element tuples can be specified:
5990 guix shell -e '(list (@@ (gnu packages bash) bash) "include")'
5993 @xref{package-development-manifest,
5994 @code{package->development-manifest}}, for information on how to write a
5995 manifest for the development environment of a package.
5997 @item --file=@var{file}
5998 @itemx -f @var{file}
5999 Create an environment containing the package or list of packages that
6000 the code within @var{file} evaluates to.
6002 As an example, @var{file} might contain a definition like this
6003 (@pxref{Defining Packages}):
6006 @verbatiminclude environment-gdb.scm
6009 With the file above, you can enter a development environment for GDB by
6013 guix shell -D -f gdb-devel.scm
6016 @anchor{shell-manifest}
6017 @item --manifest=@var{file}
6018 @itemx -m @var{file}
6019 Create an environment for the packages contained in the manifest object
6020 returned by the Scheme code in @var{file}. This option can be repeated
6021 several times, in which case the manifests are concatenated.
6023 This is similar to the same-named option in @command{guix package}
6024 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
6027 @xref{Writing Manifests}, for information on how to write a manifest.
6028 See @option{--export-manifest} below on how to obtain a first manifest.
6030 @cindex manifest, exporting
6031 @anchor{shell-export-manifest}
6032 @item --export-manifest
6033 Write to standard output a manifest suitable for @option{--manifest}
6034 corresponding to given command-line options.
6036 This is a way to ``convert'' command-line arguments into a manifest.
6037 For example, imagine you are tired of typing long lines and would like
6038 to get a manifest equivalent to this command line:
6041 guix shell -D guile git emacs emacs-geiser emacs-geiser-guile
6044 Just add @option{--export-manifest} to the command line above:
6047 guix shell --export-manifest \
6048 -D guile git emacs emacs-geiser emacs-geiser-guile
6052 ... and you get a manifest along these lines:
6055 (concatenate-manifests
6056 (list (specifications->manifest
6060 "emacs-geiser-guile"))
6061 (package->development-manifest
6062 (specification->package "guile"))))
6065 You can store it into a file, say @file{manifest.scm}, and from there
6066 pass it to @command{guix shell} or indeed pretty much any @command{guix}
6070 guix shell -m manifest.scm
6073 Voilà, you've converted a long command line into a manifest! That
6074 conversion process honors package transformation options (@pxref{Package
6075 Transformation Options}) so it should be lossless.
6077 @item --profile=@var{profile}
6078 @itemx -p @var{profile}
6079 Create an environment containing the packages installed in @var{profile}.
6080 Use @command{guix package} (@pxref{Invoking guix package}) to create
6081 and manage profiles.
6084 Unset existing environment variables when building the new environment, except
6085 those specified with @option{--preserve} (see below). This has the effect of
6086 creating an environment in which search paths only contain package inputs.
6088 @item --preserve=@var{regexp}
6089 @itemx -E @var{regexp}
6090 When used alongside @option{--pure}, preserve the environment variables
6091 matching @var{regexp}---in other words, put them on a ``white list'' of
6092 environment variables that must be preserved. This option can be repeated
6096 guix shell --pure --preserve=^SLURM openmpi @dots{} \
6100 This example runs @command{mpirun} in a context where the only environment
6101 variables defined are @env{PATH}, environment variables whose name starts
6102 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
6105 @item --search-paths
6106 Display the environment variable definitions that make up the
6109 @item --system=@var{system}
6110 @itemx -s @var{system}
6111 Attempt to build for @var{system}---e.g., @code{i686-linux}.
6116 Run @var{command} within an isolated container. The current working
6117 directory outside the container is mapped inside the container.
6118 Additionally, unless overridden with @option{--user}, a dummy home
6119 directory is created that matches the current user's home directory, and
6120 @file{/etc/passwd} is configured accordingly.
6122 The spawned process runs as the current user outside the container. Inside
6123 the container, it has the same UID and GID as the current user, unless
6124 @option{--user} is passed (see below).
6128 For containers, share the network namespace with the host system.
6129 Containers created without this flag only have access to the loopback
6132 @item --link-profile
6134 For containers, link the environment profile to @file{~/.guix-profile}
6135 within the container and set @code{GUIX_ENVIRONMENT} to that.
6136 This is equivalent to making @file{~/.guix-profile} a symlink to the
6137 actual profile within the container.
6138 Linking will fail and abort the environment if the directory already
6139 exists, which will certainly be the case if @command{guix shell}
6140 was invoked in the user's home directory.
6142 Certain packages are configured to look in @file{~/.guix-profile} for
6143 configuration files and data;@footnote{For example, the
6144 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
6145 for additional fonts.} @option{--link-profile} allows these programs to
6146 behave as expected within the environment.
6148 @item --user=@var{user}
6149 @itemx -u @var{user}
6150 For containers, use the username @var{user} in place of the current
6151 user. The generated @file{/etc/passwd} entry within the container will
6152 contain the name @var{user}, the home directory will be
6153 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
6154 the UID and GID inside the container are 1000. @var{user}
6155 need not exist on the system.
6157 Additionally, any shared or exposed path (see @option{--share} and
6158 @option{--expose} respectively) whose target is within the current user's
6159 home directory will be remapped relative to @file{/home/USER}; this
6160 includes the automatic mapping of the current working directory.
6163 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
6165 guix shell --container --user=foo \
6166 --expose=$HOME/test \
6167 --expose=/tmp/target=$HOME/target
6170 While this will limit the leaking of user identity through home paths
6171 and each of the user fields, this is only one useful component of a
6172 broader privacy/anonymity solution---not one in and of itself.
6175 For containers, the default behavior is to share the current working
6176 directory with the isolated container and immediately change to that
6177 directory within the container. If this is undesirable,
6178 @option{--no-cwd} will cause the current working directory to @emph{not}
6179 be automatically shared and will change to the user's home directory
6180 within the container instead. See also @option{--user}.
6182 @item --expose=@var{source}[=@var{target}]
6183 @itemx --share=@var{source}[=@var{target}]
6184 For containers, @option{--expose} (resp. @option{--share}) exposes the
6185 file system @var{source} from the host system as the read-only
6186 (resp. writable) file system @var{target} within the container. If
6187 @var{target} is not specified, @var{source} is used as the target mount
6188 point in the container.
6190 The example below spawns a Guile REPL in a container in which the user's
6191 home directory is accessible read-only via the @file{/exchange}
6195 guix shell --container --expose=$HOME=/exchange guile -- guile
6198 @item --rebuild-cache
6199 @cindex caching, of profiles
6200 @cindex caching, in @command{guix shell}
6201 In most cases, @command{guix shell} caches the environment so that
6202 subsequent uses are instantaneous. Least-recently used cache entries
6203 are periodically removed. The cache is also invalidated, when using
6204 @option{--file} or @option{--manifest}, anytime the corresponding file
6207 The @option{--rebuild-cache} forces the cached environment to be
6208 refreshed. This is useful when using @option{--file} or
6209 @option{--manifest} and the @command{guix.scm} or @command{manifest.scm}
6210 file has external dependencies, or if its behavior depends, say, on
6211 environment variables.
6213 @item --root=@var{file}
6214 @itemx -r @var{file}
6215 @cindex persistent environment
6216 @cindex garbage collector root, for environments
6217 Make @var{file} a symlink to the profile for this environment, and
6218 register it as a garbage collector root.
6220 This is useful if you want to protect your environment from garbage
6221 collection, to make it ``persistent''.
6223 When this option is omitted, @command{guix shell} caches profiles so
6224 that subsequent uses of the same environment are instantaneous---this is
6225 comparable to using @option{--root} except that @command{guix shell}
6226 takes care of periodically removing the least-recently used garbage
6229 In some cases, @command{guix shell} does not cache profiles---e.g., if
6230 transformation options such as @option{--with-latest} are used. In
6231 those cases, the environment is protected from garbage collection only
6232 for the duration of the @command{guix shell} session. This means that
6233 next time you recreate the same environment, you could have to rebuild
6234 or re-download packages.
6236 @xref{Invoking guix gc}, for more on GC roots.
6239 @command{guix shell} also supports all of the common build options that
6240 @command{guix build} supports (@pxref{Common Build Options}) as well as
6241 package transformation options (@pxref{Package Transformation Options}).
6243 @node Invoking guix environment
6244 @section Invoking @command{guix environment}
6246 @cindex @command{guix environment}
6248 The purpose of @command{guix environment} is to assist in creating
6249 development environments.
6251 @quotation Deprecation warning
6252 The @command{guix environment} command is deprecated in favor of
6253 @command{guix shell}, which performs similar functions but is more
6254 convenient to use. @xref{Invoking guix shell}.
6256 Being deprecated, @command{guix environment} is slated for eventual
6257 removal, but the Guix project is committed to keeping it until May 1st,
6258 2023. Please get in touch with us at @email{guix-devel@@gnu.org} if you
6259 would like to discuss it.
6262 The general syntax is:
6265 guix environment @var{options} @var{package}@dots{}
6268 The following example spawns a new shell set up for the development of
6272 guix environment guile
6275 If the needed dependencies are not built yet, @command{guix environment}
6276 automatically builds them. The environment of the new shell is an
6277 augmented version of the environment that @command{guix environment} was
6278 run in. It contains the necessary search paths for building the given
6279 package added to the existing environment variables. To create
6280 a ``pure'' environment, in which the original environment variables have
6281 been unset, use the @option{--pure} option@footnote{Users sometimes
6282 wrongfully augment environment variables such as @env{PATH} in their
6283 @file{~/.bashrc} file. As a consequence, when @command{guix
6284 environment} launches it, Bash may read @file{~/.bashrc}, thereby
6285 introducing ``impurities'' in these environment variables. It is an
6286 error to define such environment variables in @file{.bashrc}; instead,
6287 they should be defined in @file{.bash_profile}, which is sourced only by
6288 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
6289 Manual}, for details on Bash start-up files.}.
6291 Exiting from a Guix environment is the same as exiting from the shell,
6292 and will place the user back in the old environment before @command{guix
6293 environment} was invoked. The next garbage collection (@pxref{Invoking
6294 guix gc}) will clean up packages that were installed from within the
6295 environment and are no longer used outside of it.
6297 @vindex GUIX_ENVIRONMENT
6298 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
6299 variable in the shell it spawns; its value is the file name of the
6300 profile of this environment. This allows users to, say, define a
6301 specific prompt for development environments in their @file{.bashrc}
6302 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
6305 if [ -n "$GUIX_ENVIRONMENT" ]
6307 export PS1="\u@@\h \w [dev]\$ "
6312 ...@: or to browse the profile:
6315 $ ls "$GUIX_ENVIRONMENT/bin"
6318 Additionally, more than one package may be specified, in which case the
6319 union of the inputs for the given packages are used. For example, the
6320 command below spawns a shell where all of the dependencies of both Guile
6321 and Emacs are available:
6324 guix environment guile emacs
6327 Sometimes an interactive shell session is not desired. An arbitrary
6328 command may be invoked by placing the @code{--} token to separate the
6329 command from the rest of the arguments:
6332 guix environment guile -- make -j4
6335 In other situations, it is more convenient to specify the list of
6336 packages needed in the environment. For example, the following command
6337 runs @command{python} from an environment containing Python@tie{}3 and
6341 guix environment --ad-hoc python-numpy python -- python3
6344 Furthermore, one might want the dependencies of a package and also some
6345 additional packages that are not build-time or runtime dependencies, but
6346 are useful when developing nonetheless. Because of this, the
6347 @option{--ad-hoc} flag is positional. Packages appearing before
6348 @option{--ad-hoc} are interpreted as packages whose dependencies will be
6349 added to the environment. Packages appearing after are interpreted as
6350 packages that will be added to the environment directly. For example,
6351 the following command creates a Guix development environment that
6352 additionally includes Git and strace:
6355 guix environment --pure guix --ad-hoc git strace
6359 Sometimes it is desirable to isolate the environment as much as
6360 possible, for maximal purity and reproducibility. In particular, when
6361 using Guix on a host distro that is not Guix System, it is desirable to
6362 prevent access to @file{/usr/bin} and other system-wide resources from
6363 the development environment. For example, the following command spawns
6364 a Guile REPL in a ``container'' where only the store and the current
6365 working directory are mounted:
6368 guix environment --ad-hoc --container guile -- guile
6372 The @option{--container} option requires Linux-libre 3.19 or newer.
6375 @cindex certificates
6376 Another typical use case for containers is to run security-sensitive
6377 applications such as a web browser. To run Eolie, we must expose and
6378 share some files and directories; we include @code{nss-certs} and expose
6379 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
6380 @env{DISPLAY} environment variable since containerized graphical
6381 applications won't display without it.
6384 guix environment --preserve='^DISPLAY$' --container --network \
6385 --expose=/etc/machine-id \
6386 --expose=/etc/ssl/certs/ \
6387 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
6388 --ad-hoc eolie nss-certs dbus -- eolie
6391 The available options are summarized below.
6395 Set up the environment and check whether the shell would clobber
6396 environment variables. @xref{Invoking guix shell, @option{--check}},
6399 @item --root=@var{file}
6400 @itemx -r @var{file}
6401 @cindex persistent environment
6402 @cindex garbage collector root, for environments
6403 Make @var{file} a symlink to the profile for this environment, and
6404 register it as a garbage collector root.
6406 This is useful if you want to protect your environment from garbage
6407 collection, to make it ``persistent''.
6409 When this option is omitted, the environment is protected from garbage
6410 collection only for the duration of the @command{guix environment}
6411 session. This means that next time you recreate the same environment,
6412 you could have to rebuild or re-download packages. @xref{Invoking guix
6413 gc}, for more on GC roots.
6415 @item --expression=@var{expr}
6416 @itemx -e @var{expr}
6417 Create an environment for the package or list of packages that
6418 @var{expr} evaluates to.
6420 For example, running:
6423 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
6426 starts a shell with the environment for this specific variant of the
6432 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
6435 starts a shell with all the base system packages available.
6437 The above commands only use the default output of the given packages.
6438 To select other outputs, two element tuples can be specified:
6441 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
6444 @item --load=@var{file}
6445 @itemx -l @var{file}
6446 Create an environment for the package or list of packages that the code
6447 within @var{file} evaluates to.
6449 As an example, @var{file} might contain a definition like this
6450 (@pxref{Defining Packages}):
6453 @verbatiminclude environment-gdb.scm
6456 @item --manifest=@var{file}
6457 @itemx -m @var{file}
6458 Create an environment for the packages contained in the manifest object
6459 returned by the Scheme code in @var{file}. This option can be repeated
6460 several times, in which case the manifests are concatenated.
6462 This is similar to the same-named option in @command{guix package}
6463 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
6466 @xref{shell-export-manifest, @command{guix shell --export-manifest}},
6467 for information on how to ``convert'' command-line options into a
6471 Include all specified packages in the resulting environment, as if an
6472 @i{ad hoc} package were defined with them as inputs. This option is
6473 useful for quickly creating an environment without having to write a
6474 package expression to contain the desired inputs.
6476 For instance, the command:
6479 guix environment --ad-hoc guile guile-sdl -- guile
6482 runs @command{guile} in an environment where Guile and Guile-SDL are
6485 Note that this example implicitly asks for the default output of
6486 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
6487 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
6488 of @code{glib} (@pxref{Packages with Multiple Outputs}).
6490 This option may be composed with the default behavior of @command{guix
6491 environment}. Packages appearing before @option{--ad-hoc} are
6492 interpreted as packages whose dependencies will be added to the
6493 environment, the default behavior. Packages appearing after are
6494 interpreted as packages that will be added to the environment directly.
6496 @item --profile=@var{profile}
6497 @itemx -p @var{profile}
6498 Create an environment containing the packages installed in @var{profile}.
6499 Use @command{guix package} (@pxref{Invoking guix package}) to create
6500 and manage profiles.
6503 Unset existing environment variables when building the new environment, except
6504 those specified with @option{--preserve} (see below). This has the effect of
6505 creating an environment in which search paths only contain package inputs.
6507 @item --preserve=@var{regexp}
6508 @itemx -E @var{regexp}
6509 When used alongside @option{--pure}, preserve the environment variables
6510 matching @var{regexp}---in other words, put them on a ``white list'' of
6511 environment variables that must be preserved. This option can be repeated
6515 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
6519 This example runs @command{mpirun} in a context where the only environment
6520 variables defined are @env{PATH}, environment variables whose name starts
6521 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
6524 @item --search-paths
6525 Display the environment variable definitions that make up the
6528 @item --system=@var{system}
6529 @itemx -s @var{system}
6530 Attempt to build for @var{system}---e.g., @code{i686-linux}.
6535 Run @var{command} within an isolated container. The current working
6536 directory outside the container is mapped inside the container.
6537 Additionally, unless overridden with @option{--user}, a dummy home
6538 directory is created that matches the current user's home directory, and
6539 @file{/etc/passwd} is configured accordingly.
6541 The spawned process runs as the current user outside the container. Inside
6542 the container, it has the same UID and GID as the current user, unless
6543 @option{--user} is passed (see below).
6547 For containers, share the network namespace with the host system.
6548 Containers created without this flag only have access to the loopback
6551 @item --link-profile
6553 For containers, link the environment profile to @file{~/.guix-profile}
6554 within the container and set @code{GUIX_ENVIRONMENT} to that.
6555 This is equivalent to making @file{~/.guix-profile} a symlink to the
6556 actual profile within the container.
6557 Linking will fail and abort the environment if the directory already
6558 exists, which will certainly be the case if @command{guix environment}
6559 was invoked in the user's home directory.
6561 Certain packages are configured to look in @file{~/.guix-profile} for
6562 configuration files and data;@footnote{For example, the
6563 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
6564 for additional fonts.} @option{--link-profile} allows these programs to
6565 behave as expected within the environment.
6567 @item --user=@var{user}
6568 @itemx -u @var{user}
6569 For containers, use the username @var{user} in place of the current
6570 user. The generated @file{/etc/passwd} entry within the container will
6571 contain the name @var{user}, the home directory will be
6572 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
6573 the UID and GID inside the container are 1000. @var{user}
6574 need not exist on the system.
6576 Additionally, any shared or exposed path (see @option{--share} and
6577 @option{--expose} respectively) whose target is within the current user's
6578 home directory will be remapped relative to @file{/home/USER}; this
6579 includes the automatic mapping of the current working directory.
6582 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
6584 guix environment --container --user=foo \
6585 --expose=$HOME/test \
6586 --expose=/tmp/target=$HOME/target
6589 While this will limit the leaking of user identity through home paths
6590 and each of the user fields, this is only one useful component of a
6591 broader privacy/anonymity solution---not one in and of itself.
6594 For containers, the default behavior is to share the current working
6595 directory with the isolated container and immediately change to that
6596 directory within the container. If this is undesirable,
6597 @option{--no-cwd} will cause the current working directory to @emph{not}
6598 be automatically shared and will change to the user's home directory
6599 within the container instead. See also @option{--user}.
6601 @item --expose=@var{source}[=@var{target}]
6602 @itemx --share=@var{source}[=@var{target}]
6603 For containers, @option{--expose} (resp. @option{--share}) exposes the
6604 file system @var{source} from the host system as the read-only
6605 (resp. writable) file system @var{target} within the container. If
6606 @var{target} is not specified, @var{source} is used as the target mount
6607 point in the container.
6609 The example below spawns a Guile REPL in a container in which the user's
6610 home directory is accessible read-only via the @file{/exchange}
6614 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
6619 @command{guix environment}
6620 also supports all of the common build options that @command{guix
6621 build} supports (@pxref{Common Build Options}) as well as package
6622 transformation options (@pxref{Package Transformation Options}).
6624 @node Invoking guix pack
6625 @section Invoking @command{guix pack}
6627 @cindex @command{guix pack}
6629 Occasionally you want to pass software to people who are not (yet!)
6630 lucky enough to be using Guix. You'd tell them to run @command{guix
6631 package -i @var{something}}, but that's not possible in this case. This
6632 is where @command{guix pack} comes in.
6635 If you are looking for ways to exchange binaries among machines that
6636 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
6637 publish}, and @ref{Invoking guix archive}.
6642 @cindex application bundle
6643 @cindex software bundle
6644 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
6645 @dfn{software bundle}: it creates a tarball or some other archive
6646 containing the binaries of the software you're interested in, and all
6647 its dependencies. The resulting archive can be used on any machine that
6648 does not have Guix, and people can run the exact same binaries as those
6649 you have with Guix. The pack itself is created in a bit-reproducible
6650 fashion, so anyone can verify that it really contains the build results
6651 that you pretend to be shipping.
6653 For example, to create a bundle containing Guile, Emacs, Geiser, and all
6654 their dependencies, you can run:
6657 $ guix pack guile emacs emacs-geiser
6659 /gnu/store/@dots{}-pack.tar.gz
6662 The result here is a tarball containing a @file{/gnu/store} directory
6663 with all the relevant packages. The resulting tarball contains a
6664 @dfn{profile} with the three packages of interest; the profile is the
6665 same as would be created by @command{guix package -i}. It is this
6666 mechanism that is used to create Guix's own standalone binary tarball
6667 (@pxref{Binary Installation}).
6669 Users of this pack would have to run
6670 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
6671 find inconvenient. To work around it, you can create, say, a
6672 @file{/opt/gnu/bin} symlink to the profile:
6675 guix pack -S /opt/gnu/bin=bin guile emacs emacs-geiser
6679 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
6681 @cindex relocatable binaries, with @command{guix pack}
6682 What if the recipient of your pack does not have root privileges on
6683 their machine, and thus cannot unpack it in the root file system? In
6684 that case, you will want to use the @option{--relocatable} option (see
6685 below). This option produces @dfn{relocatable binaries}, meaning they
6686 they can be placed anywhere in the file system hierarchy: in the example
6687 above, users can unpack your tarball in their home directory and
6688 directly run @file{./opt/gnu/bin/guile}.
6690 @cindex Docker, build an image with guix pack
6691 Alternatively, you can produce a pack in the Docker image format using
6692 the following command:
6695 guix pack -f docker -S /bin=bin guile guile-readline
6699 The result is a tarball that can be passed to the @command{docker load}
6700 command, followed by @code{docker run}:
6703 docker load < @var{file}
6704 docker run -ti guile-guile-readline /bin/guile
6708 where @var{file} is the image returned by @var{guix pack}, and
6709 @code{guile-guile-readline} is its ``image tag''. See the
6710 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
6711 documentation} for more information.
6713 @cindex Singularity, build an image with guix pack
6714 @cindex SquashFS, build an image with guix pack
6715 Yet another option is to produce a SquashFS image with the following
6719 guix pack -f squashfs bash guile emacs emacs-geiser
6723 The result is a SquashFS file system image that can either be mounted or
6724 directly be used as a file system container image with the
6725 @uref{https://www.sylabs.io/docs/, Singularity container execution
6726 environment}, using commands like @command{singularity shell} or
6727 @command{singularity exec}.
6729 Several command-line options allow you to customize your pack:
6732 @item --format=@var{format}
6733 @itemx -f @var{format}
6734 Produce a pack in the given @var{format}.
6736 The available formats are:
6740 This is the default format. It produces a tarball containing all the
6741 specified binaries and symlinks.
6744 This produces a tarball that follows the
6745 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
6746 Docker Image Specification}. The ``repository name'' as it appears in
6747 the output of the @command{docker images} command is computed from
6748 package names passed on the command line or in the manifest file.
6751 This produces a SquashFS image containing all the specified binaries and
6752 symlinks, as well as empty mount points for virtual file systems like
6756 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
6757 For that reason, @command{guix pack -f squashfs} always implies @code{-S
6758 /bin=bin}. Thus, your @command{guix pack} invocation must always start
6759 with something like:
6762 guix pack -f squashfs bash @dots{}
6765 If you forget the @code{bash} (or similar) package, @command{singularity
6766 run} and @command{singularity exec} will fail with an unhelpful ``no
6767 such file or directory'' message.
6771 This produces a Debian archive (a package with the @samp{.deb} file
6772 extension) containing all the specified binaries and symbolic links,
6773 that can be installed on top of any dpkg-based GNU(/Linux) distribution.
6774 Advanced options can be revealed via the @option{--help-deb-format}
6775 option. They allow embedding control files for more fine-grained
6776 control, such as activating specific triggers or providing a maintainer
6777 configure script to run arbitrary setup code upon installation.
6780 guix pack -f deb -C xz -S /usr/bin/hello=bin/hello hello
6784 Because archives produced with @command{guix pack} contain a collection
6785 of store items and because each @command{dpkg} package must not have
6786 conflicting files, in practice that means you likely won't be able to
6787 install more than one such archive on a given system.
6791 @command{dpkg} will assume ownership of any files contained in the pack
6792 that it does @emph{not} know about. It is unwise to install
6793 Guix-produced @samp{.deb} files on a system where @file{/gnu/store} is
6794 shared by other software, such as a Guix installation or other, non-deb
6800 @cindex relocatable binaries
6803 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
6804 anywhere in the file system hierarchy and run from there.
6806 When this option is passed once, the resulting binaries require support for
6807 @dfn{user namespaces} in the kernel Linux; when passed
6808 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
6809 PRoot support, can be thought of as the abbreviation of ``Really
6810 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
6811 other techniques if user namespaces are unavailable, and essentially
6812 work anywhere---see below for the implications.
6814 For example, if you create a pack containing Bash with:
6817 guix pack -RR -S /mybin=bin bash
6821 ...@: you can copy that pack to a machine that lacks Guix, and from your
6822 home directory as a normal user, run:
6830 In that shell, if you type @code{ls /gnu/store}, you'll notice that
6831 @file{/gnu/store} shows up and contains all the dependencies of
6832 @code{bash}, even though the machine actually lacks @file{/gnu/store}
6833 altogether! That is probably the simplest way to deploy Guix-built
6834 software on a non-Guix machine.
6837 By default, relocatable binaries rely on the @dfn{user namespace} feature of
6838 the kernel Linux, which allows unprivileged users to mount or change root.
6839 Old versions of Linux did not support it, and some GNU/Linux distributions
6842 To produce relocatable binaries that work even in the absence of user
6843 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
6844 case, binaries will try user namespace support and fall back to another
6845 @dfn{execution engine} if user namespaces are not supported. The
6846 following execution engines are supported:
6850 Try user namespaces and fall back to PRoot if user namespaces are not
6851 supported (see below).
6854 Try user namespaces and fall back to Fakechroot if user namespaces are
6855 not supported (see below).
6858 Run the program through user namespaces and abort if they are not
6862 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
6863 provides the necessary
6864 support for file system virtualization. It achieves that by using the
6865 @code{ptrace} system call on the running program. This approach has the
6866 advantage to work without requiring special kernel support, but it incurs
6867 run-time overhead every time a system call is made.
6870 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
6871 Fakechroot} virtualizes file system accesses by intercepting calls to C
6872 library functions such as @code{open}, @code{stat}, @code{exec}, and so
6873 on. Unlike PRoot, it incurs very little overhead. However, it does not
6874 always work: for example, some file system accesses made from within the
6875 C library are not intercepted, and file system accesses made @i{via}
6876 direct syscalls are not intercepted either, leading to erratic behavior.
6879 @vindex GUIX_EXECUTION_ENGINE
6880 When running a wrapped program, you can explicitly request one of the
6881 execution engines listed above by setting the
6882 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
6885 @cindex entry point, for Docker images
6886 @item --entry-point=@var{command}
6887 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6888 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6889 support it. @var{command} must be relative to the profile contained in the
6892 The entry point specifies the command that tools like @code{docker run} or
6893 @code{singularity run} automatically start by default. For example, you can
6897 guix pack -f docker --entry-point=bin/guile guile
6900 The resulting pack can easily be loaded and @code{docker run} with no extra
6901 arguments will spawn @code{bin/guile}:
6904 docker load -i pack.tar.gz
6905 docker run @var{image-id}
6908 @item --expression=@var{expr}
6909 @itemx -e @var{expr}
6910 Consider the package @var{expr} evaluates to.
6912 This has the same purpose as the same-named option in @command{guix
6913 build} (@pxref{Additional Build Options, @option{--expression} in
6914 @command{guix build}}).
6916 @anchor{pack-manifest}
6917 @item --manifest=@var{file}
6918 @itemx -m @var{file}
6919 Use the packages contained in the manifest object returned by the Scheme
6920 code in @var{file}. This option can be repeated several times, in which
6921 case the manifests are concatenated.
6923 This has a similar purpose as the same-named option in @command{guix
6924 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6925 same manifest files. It allows you to define a collection of packages
6926 once and use it both for creating profiles and for creating archives
6927 for use on machines that do not have Guix installed. Note that you can
6928 specify @emph{either} a manifest file @emph{or} a list of packages,
6931 @xref{Writing Manifests}, for information on how to write a manifest.
6932 @xref{shell-export-manifest, @command{guix shell --export-manifest}},
6933 for information on how to ``convert'' command-line options into a
6936 @item --system=@var{system}
6937 @itemx -s @var{system}
6938 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6939 the system type of the build host.
6941 @item --target=@var{triplet}
6942 @cindex cross-compilation
6943 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6944 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6945 configuration triplets,, autoconf, Autoconf}).
6947 @item --compression=@var{tool}
6948 @itemx -C @var{tool}
6949 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6950 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6953 @item --symlink=@var{spec}
6954 @itemx -S @var{spec}
6955 Add the symlinks specified by @var{spec} to the pack. This option can
6956 appear several times.
6958 @var{spec} has the form @code{@var{source}=@var{target}}, where
6959 @var{source} is the symlink that will be created and @var{target} is the
6962 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6963 symlink pointing to the @file{bin} sub-directory of the profile.
6965 @item --save-provenance
6966 Save provenance information for the packages passed on the command line.
6967 Provenance information includes the URL and commit of the channels in use
6970 Provenance information is saved in the
6971 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6972 usual package metadata---the name and version of each package, their
6973 propagated inputs, and so on. It is useful information to the recipient of
6974 the pack, who then knows how the pack was (supposedly) obtained.
6976 This option is not enabled by default because, like timestamps, provenance
6977 information contributes nothing to the build process. In other words, there
6978 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6979 Recording such ``silent'' metadata in the output thus potentially breaks the
6980 source-to-binary bitwise reproducibility property.
6982 @item --root=@var{file}
6983 @itemx -r @var{file}
6984 @cindex garbage collector root, for packs
6985 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6988 @item --localstatedir
6989 @itemx --profile-name=@var{name}
6990 Include the ``local state directory'', @file{/var/guix}, in the resulting
6991 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6992 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6993 @file{~root/.guix-profile}.
6995 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6996 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6997 the pack means that the store is ``complete'' and manageable by Guix;
6998 not providing it pack means that the store is ``dead'': items cannot be
6999 added to it or removed from it after extraction of the pack.
7001 One use case for this is the Guix self-contained binary tarball
7002 (@pxref{Binary Installation}).
7006 Print the name of the derivation that builds the pack.
7009 Use the bootstrap binaries to build the pack. This option is only
7010 useful to Guix developers.
7013 In addition, @command{guix pack} supports all the common build options
7014 (@pxref{Common Build Options}) and all the package transformation
7015 options (@pxref{Package Transformation Options}).
7018 @node The GCC toolchain
7019 @section The GCC toolchain
7023 @cindex linker wrapper
7024 @cindex toolchain, for C development
7025 @cindex toolchain, for Fortran development
7027 If you need a complete toolchain for compiling and linking C or C++
7028 source code, use the @code{gcc-toolchain} package. This package
7029 provides a complete GCC toolchain for C/C++ development, including GCC
7030 itself, the GNU C Library (headers and binaries, plus debugging symbols
7031 in the @code{debug} output), Binutils, and a linker wrapper.
7033 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
7034 passed to the linker, add corresponding @code{-rpath} arguments, and
7035 invoke the actual linker with this new set of arguments. You can instruct the
7036 wrapper to refuse to link against libraries not in the store by setting the
7037 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
7039 The package @code{gfortran-toolchain} provides a complete GCC toolchain
7040 for Fortran development. For other languages, please use
7041 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
7044 @node Invoking guix git authenticate
7045 @section Invoking @command{guix git authenticate}
7047 @cindex @command{guix git authenticate}
7049 The @command{guix git authenticate} command authenticates a Git checkout
7050 following the same rule as for channels (@pxref{channel-authentication,
7051 channel authentication}). That is, starting from a given commit, it
7052 ensures that all subsequent commits are signed by an OpenPGP key whose
7053 fingerprint appears in the @file{.guix-authorizations} file of its
7056 You will find this command useful if you maintain a channel. But in
7057 fact, this authentication mechanism is useful in a broader context, so
7058 you might want to use it for Git repositories that have nothing to do
7061 The general syntax is:
7064 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
7067 By default, this command authenticates the Git checkout in the current
7068 directory; it outputs nothing and exits with exit code zero on success
7069 and non-zero on failure. @var{commit} above denotes the first commit
7070 where authentication takes place, and @var{signer} is the OpenPGP
7071 fingerprint of public key used to sign @var{commit}. Together, they
7072 form a ``channel introduction'' (@pxref{channel-authentication, channel
7073 introduction}). The options below allow you to fine-tune the process.
7076 @item --repository=@var{directory}
7077 @itemx -r @var{directory}
7078 Open the Git repository in @var{directory} instead of the current
7081 @item --keyring=@var{reference}
7082 @itemx -k @var{reference}
7083 Load OpenPGP keyring from @var{reference}, the reference of a branch
7084 such as @code{origin/keyring} or @code{my-keyring}. The branch must
7085 contain OpenPGP public keys in @file{.key} files, either in binary form
7086 or ``ASCII-armored''. By default the keyring is loaded from the branch
7087 named @code{keyring}.
7090 Display commit signing statistics upon completion.
7092 @item --cache-key=@var{key}
7093 Previously-authenticated commits are cached in a file under
7094 @file{~/.cache/guix/authentication}. This option forces the cache to be
7095 stored in file @var{key} in that directory.
7097 @item --historical-authorizations=@var{file}
7098 By default, any commit whose parent commit(s) lack the
7099 @file{.guix-authorizations} file is considered inauthentic. In
7100 contrast, this option considers the authorizations in @var{file} for any
7101 commit that lacks @file{.guix-authorizations}. The format of @var{file}
7102 is the same as that of @file{.guix-authorizations}
7103 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
7107 @c *********************************************************************
7108 @node Programming Interface
7109 @chapter Programming Interface
7111 GNU Guix provides several Scheme programming interfaces (APIs) to
7112 define, build, and query packages. The first interface allows users to
7113 write high-level package definitions. These definitions refer to
7114 familiar packaging concepts, such as the name and version of a package,
7115 its build system, and its dependencies. These definitions can then be
7116 turned into concrete build actions.
7118 Build actions are performed by the Guix daemon, on behalf of users. In a
7119 standard setup, the daemon has write access to the store---the
7120 @file{/gnu/store} directory---whereas users do not. The recommended
7121 setup also has the daemon perform builds in chroots, under specific
7122 build users, to minimize interference with the rest of the system.
7125 Lower-level APIs are available to interact with the daemon and the
7126 store. To instruct the daemon to perform a build action, users actually
7127 provide it with a @dfn{derivation}. A derivation is a low-level
7128 representation of the build actions to be taken, and the environment in
7129 which they should occur---derivations are to package definitions what
7130 assembly is to C programs. The term ``derivation'' comes from the fact
7131 that build results @emph{derive} from them.
7133 This chapter describes all these APIs in turn, starting from high-level
7134 package definitions.
7137 * Package Modules:: Packages from the programmer's viewpoint.
7138 * Defining Packages:: Defining new packages.
7139 * Defining Package Variants:: Customizing packages.
7140 * Writing Manifests:: The bill of materials of your environment.
7141 * Build Systems:: Specifying how packages are built.
7142 * Build Phases:: Phases of the build process of a package.
7143 * Build Utilities:: Helpers for your package definitions and more.
7144 * Search Paths:: Declaring search path environment variables.
7145 * The Store:: Manipulating the package store.
7146 * Derivations:: Low-level interface to package derivations.
7147 * The Store Monad:: Purely functional interface to the store.
7148 * G-Expressions:: Manipulating build expressions.
7149 * Invoking guix repl:: Programming Guix in Guile
7150 * Using Guix Interactively:: Fine-grain interaction at the REPL.
7153 @node Package Modules
7154 @section Package Modules
7156 From a programming viewpoint, the package definitions of the
7157 GNU distribution are provided by Guile modules in the @code{(gnu packages
7158 @dots{})} name space@footnote{Note that packages under the @code{(gnu
7159 packages @dots{})} module name space are not necessarily ``GNU
7160 packages''. This module naming scheme follows the usual Guile module
7161 naming convention: @code{gnu} means that these modules are distributed
7162 as part of the GNU system, and @code{packages} identifies modules that
7163 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
7164 Reference Manual}). For instance, the @code{(gnu packages emacs)}
7165 module exports a variable named @code{emacs}, which is bound to a
7166 @code{<package>} object (@pxref{Defining Packages}).
7168 The @code{(gnu packages @dots{})} module name space is
7169 automatically scanned for packages by the command-line tools. For
7170 instance, when running @code{guix install emacs}, all the @code{(gnu
7171 packages @dots{})} modules are scanned until one that exports a package
7172 object whose name is @code{emacs} is found. This package search
7173 facility is implemented in the @code{(gnu packages)} module.
7175 @cindex customization, of packages
7176 @cindex package module search path
7177 Users can store package definitions in modules with different
7178 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
7179 name and module name must match. For instance, the @code{(my-packages
7180 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
7181 relative to the load path specified with @option{--load-path} or
7182 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
7183 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
7184 these package definitions visible to the user interfaces:
7188 By adding the directory containing your package modules to the search path
7189 with the @code{-L} flag of @command{guix package} and other commands
7190 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
7191 environment variable described below.
7194 By defining a @dfn{channel} and configuring @command{guix pull} so that it
7195 pulls from it. A channel is essentially a Git repository containing package
7196 modules. @xref{Channels}, for more information on how to define and use
7200 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
7202 @defvr {Environment Variable} GUIX_PACKAGE_PATH
7203 This is a colon-separated list of directories to search for additional
7204 package modules. Directories listed in this variable take precedence
7205 over the own modules of the distribution.
7208 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
7209 each package is built based solely on other packages in the
7210 distribution. The root of this dependency graph is a small set of
7211 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
7212 bootstrap)} module. For more information on bootstrapping,
7213 @pxref{Bootstrapping}.
7215 @node Defining Packages
7216 @section Defining Packages
7218 The high-level interface to package definitions is implemented in the
7219 @code{(guix packages)} and @code{(guix build-system)} modules. As an
7220 example, the package definition, or @dfn{recipe}, for the GNU Hello
7221 package looks like this:
7224 (define-module (gnu packages hello)
7225 #:use-module (guix packages)
7226 #:use-module (guix download)
7227 #:use-module (guix build-system gnu)
7228 #:use-module (guix licenses)
7229 #:use-module (gnu packages gawk))
7231 (define-public hello
7237 (uri (string-append "mirror://gnu/hello/hello-" version
7241 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
7242 (build-system gnu-build-system)
7243 (arguments '(#:configure-flags '("--enable-silent-rules")))
7244 (inputs (list gawk))
7245 (synopsis "Hello, GNU world: An example GNU package")
7246 (description "Guess what GNU Hello prints!")
7247 (home-page "https://www.gnu.org/software/hello/")
7252 Without being a Scheme expert, the reader may have guessed the meaning
7253 of the various fields here. This expression binds the variable
7254 @code{hello} to a @code{<package>} object, which is essentially a record
7255 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
7256 This package object can be inspected using procedures found in the
7257 @code{(guix packages)} module; for instance, @code{(package-name hello)}
7258 returns---surprise!---@code{"hello"}.
7260 With luck, you may be able to import part or all of the definition of
7261 the package you are interested in from another repository, using the
7262 @code{guix import} command (@pxref{Invoking guix import}).
7264 In the example above, @code{hello} is defined in a module of its own,
7265 @code{(gnu packages hello)}. Technically, this is not strictly
7266 necessary, but it is convenient to do so: all the packages defined in
7267 modules under @code{(gnu packages @dots{})} are automatically known to
7268 the command-line tools (@pxref{Package Modules}).
7270 There are a few points worth noting in the above package definition:
7274 The @code{source} field of the package is an @code{<origin>} object
7275 (@pxref{origin Reference}, for the complete reference).
7276 Here, the @code{url-fetch} method from @code{(guix download)} is used,
7277 meaning that the source is a file to be downloaded over FTP or HTTP.
7279 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
7280 the GNU mirrors defined in @code{(guix download)}.
7282 The @code{sha256} field specifies the expected SHA256 hash of the file
7283 being downloaded. It is mandatory, and allows Guix to check the
7284 integrity of the file. The @code{(base32 @dots{})} form introduces the
7285 base32 representation of the hash. You can obtain this information with
7286 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
7287 hash} (@pxref{Invoking guix hash}).
7290 When needed, the @code{origin} form can also have a @code{patches} field
7291 listing patches to be applied, and a @code{snippet} field giving a
7292 Scheme expression to modify the source code.
7295 @cindex GNU Build System
7296 The @code{build-system} field specifies the procedure to build the
7297 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
7298 represents the familiar GNU Build System, where packages may be
7299 configured, built, and installed with the usual @code{./configure &&
7300 make && make check && make install} command sequence.
7302 When you start packaging non-trivial software, you may need tools to
7303 manipulate those build phases, manipulate files, and so on. @xref{Build
7304 Utilities}, for more on this.
7307 The @code{arguments} field specifies options for the build system
7308 (@pxref{Build Systems}). Here it is interpreted by
7309 @code{gnu-build-system} as a request run @file{configure} with the
7310 @option{--enable-silent-rules} flag.
7316 @cindex backquote (quasiquote)
7319 @cindex comma (unquote)
7322 What about these quote (@code{'}) characters? They are Scheme syntax to
7323 introduce a literal list; @code{'} is synonymous with @code{quote}.
7324 Sometimes you'll also see @code{`} (a backquote, synonymous with
7325 @code{quasiquote}) and @code{,} (a comma, synonymous with @code{unquote}).
7326 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
7327 for details. Here the value of the @code{arguments} field is a list of
7328 arguments passed to the build system down the road, as with @code{apply}
7329 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
7332 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
7333 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
7334 @code{#:configure-flags} is a keyword used to pass a keyword argument
7335 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
7339 The @code{inputs} field specifies inputs to the build process---i.e.,
7340 build-time or run-time dependencies of the package. Here, we add
7341 an input, a reference to the @code{gawk}
7342 variable; @code{gawk} is itself bound to a @code{<package>} object.
7344 Note that GCC, Coreutils, Bash, and other essential tools do not need to
7345 be specified as inputs here. Instead, @code{gnu-build-system} takes care
7346 of ensuring that they are present (@pxref{Build Systems}).
7348 However, any other dependencies need to be specified in the
7349 @code{inputs} field. Any dependency not specified here will simply be
7350 unavailable to the build process, possibly leading to a build failure.
7353 @xref{package Reference}, for a full description of possible fields.
7355 @quotation Going further
7356 @cindex Scheme programming language, getting started
7357 Intimidated by the Scheme language or curious about it? The Cookbook
7358 has a short section to get started that recaps some of the things shown
7359 above and explains the fundamentals. @xref{A Scheme Crash Course,,,
7360 guix-cookbook, GNU Guix Cookbook}, for more information.
7363 Once a package definition is in place, the
7364 package may actually be built using the @code{guix build} command-line
7365 tool (@pxref{Invoking guix build}), troubleshooting any build failures
7366 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
7367 package definition using the @command{guix edit} command
7368 (@pxref{Invoking guix edit}).
7369 @xref{Packaging Guidelines}, for
7370 more information on how to test package definitions, and
7371 @ref{Invoking guix lint}, for information on how to check a definition
7372 for style conformance.
7373 @vindex GUIX_PACKAGE_PATH
7374 Lastly, @pxref{Channels}, for information
7375 on how to extend the distribution by adding your own package definitions
7378 Finally, updating the package definition to a new upstream version
7379 can be partly automated by the @command{guix refresh} command
7380 (@pxref{Invoking guix refresh}).
7382 Behind the scenes, a derivation corresponding to the @code{<package>}
7383 object is first computed by the @code{package-derivation} procedure.
7384 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
7385 The build actions it prescribes may then be realized by using the
7386 @code{build-derivations} procedure (@pxref{The Store}).
7388 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
7389 Return the @code{<derivation>} object of @var{package} for @var{system}
7390 (@pxref{Derivations}).
7392 @var{package} must be a valid @code{<package>} object, and @var{system}
7393 must be a string denoting the target system type---e.g.,
7394 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
7395 must be a connection to the daemon, which operates on the store
7396 (@pxref{The Store}).
7400 @cindex cross-compilation
7401 Similarly, it is possible to compute a derivation that cross-builds a
7402 package for some other system:
7404 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
7405 @var{package} @var{target} [@var{system}]
7406 Return the @code{<derivation>} object of @var{package} cross-built from
7407 @var{system} to @var{target}.
7409 @var{target} must be a valid GNU triplet denoting the target hardware
7410 and operating system, such as @code{"aarch64-linux-gnu"}
7411 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
7414 Once you have package definitions, you can easily define @emph{variants}
7415 of those packages. @xref{Defining Package Variants}, for more on that.
7418 * package Reference:: The package data type.
7419 * origin Reference:: The origin data type.
7423 @node package Reference
7424 @subsection @code{package} Reference
7426 This section summarizes all the options available in @code{package}
7427 declarations (@pxref{Defining Packages}).
7429 @deftp {Data Type} package
7430 This is the data type representing a package recipe.
7434 The name of the package, as a string.
7436 @item @code{version}
7437 The version of the package, as a string. @xref{Version Numbers}, for
7441 An object telling how the source code for the package should be
7442 acquired. Most of the time, this is an @code{origin} object, which
7443 denotes a file fetched from the Internet (@pxref{origin Reference}). It
7444 can also be any other ``file-like'' object such as a @code{local-file},
7445 which denotes a file from the local file system (@pxref{G-Expressions,
7446 @code{local-file}}).
7448 @item @code{build-system}
7449 The build system that should be used to build the package (@pxref{Build
7452 @item @code{arguments} (default: @code{'()})
7453 The arguments that should be passed to the build system (@pxref{Build
7454 Systems}). This is a list, typically containing sequential
7455 keyword-value pairs, as in this example:
7460 ;; several fields omitted
7462 (list #:tests? #f ;skip tests
7463 #:make-flags #~'("VERBOSE=1") ;pass flags to 'make'
7464 #:configure-flags #~'("--enable-frobbing"))))
7467 The exact set of supported keywords depends on the build system
7468 (@pxref{Build Systems}), but you will find that almost all of them honor
7469 @code{#:configure-flags}, @code{#:make-flags}, @code{#:tests?}, and
7470 @code{#:phases}. The @code{#:phases} keyword in particular lets you
7471 modify the set of build phases for your package (@pxref{Build Phases}).
7473 @item @code{inputs} (default: @code{'()})
7474 @itemx @code{native-inputs} (default: @code{'()})
7475 @itemx @code{propagated-inputs} (default: @code{'()})
7476 @cindex inputs, of packages
7477 These fields list dependencies of the package. Each element of these
7478 lists is either a package, origin, or other ``file-like object''
7479 (@pxref{G-Expressions}); to specify the output of that file-like object
7480 that should be used, pass a two-element list where the second element is
7481 the output (@pxref{Packages with Multiple Outputs}, for more on package
7482 outputs). For example, the list below specifies three inputs:
7485 (list libffi libunistring
7486 `(,glib "bin")) ;the "bin" output of GLib
7489 In the example above, the @code{"out"} output of @code{libffi} and
7490 @code{libunistring} is used.
7492 @quotation Compatibility Note
7493 Until version 1.3.0, input lists were a list of tuples,
7494 where each tuple has a label for the input (a string) as its
7495 first element, a package, origin, or derivation as its second element,
7496 and optionally the name of the output thereof that should be used, which
7497 defaults to @code{"out"}. For example, the list below is equivalent to
7498 the one above, but using the @dfn{old input style}:
7501 ;; Old input style (deprecated).
7502 `(("libffi" ,libffi)
7503 ("libunistring" ,libunistring)
7504 ("glib:bin" ,glib "bin")) ;the "bin" output of GLib
7507 This style is now deprecated; it is still supported but support will be
7508 removed in a future version. It should not be used for new package
7509 definitions. @xref{Invoking guix style}, on how to migrate to the new
7513 @cindex cross compilation, package dependencies
7514 The distinction between @code{native-inputs} and @code{inputs} is
7515 necessary when considering cross-compilation. When cross-compiling,
7516 dependencies listed in @code{inputs} are built for the @emph{target}
7517 architecture; conversely, dependencies listed in @code{native-inputs}
7518 are built for the architecture of the @emph{build} machine.
7520 @code{native-inputs} is typically used to list tools needed at
7521 build time, but not at run time, such as Autoconf, Automake, pkg-config,
7522 Gettext, or Bison. @command{guix lint} can report likely mistakes in
7523 this area (@pxref{Invoking guix lint}).
7525 @anchor{package-propagated-inputs}
7526 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
7527 specified packages will be automatically installed to profiles
7528 (@pxref{Features, the role of profiles in Guix}) alongside the package
7529 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
7530 package}}, for information on how @command{guix package} deals with
7533 For example this is necessary when packaging a C/C++ library that needs
7534 headers of another library to compile, or when a pkg-config file refers
7535 to another one @i{via} its @code{Requires} field.
7537 Another example where @code{propagated-inputs} is useful is for languages
7538 that lack a facility to record the run-time search path akin to the
7539 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
7540 more. When packaging libraries written in those languages, ensure they
7541 can find library code they depend on at run time by listing run-time
7542 dependencies in @code{propagated-inputs} rather than @code{inputs}.
7544 @item @code{outputs} (default: @code{'("out")})
7545 The list of output names of the package. @xref{Packages with Multiple
7546 Outputs}, for typical uses of additional outputs.
7548 @item @code{native-search-paths} (default: @code{'()})
7549 @itemx @code{search-paths} (default: @code{'()})
7550 A list of @code{search-path-specification} objects describing
7551 search-path environment variables honored by the package. @xref{Search
7552 Paths}, for more on search path specifications.
7554 As for inputs, the distinction between @code{native-search-paths} and
7555 @code{search-paths} only matters when cross-compiling. In a
7556 cross-compilation context, @code{native-search-paths} applies
7557 exclusively to native inputs whereas @code{search-paths} applies only to
7560 Packages such as cross-compilers care about target inputs---for
7561 instance, our (modified) GCC cross-compiler has
7562 @env{CROSS_C_INCLUDE_PATH} in @code{search-paths}, which allows it to
7563 pick @file{.h} files for the target system and @emph{not} those of
7564 native inputs. For the majority of packages though, only
7565 @code{native-search-paths} makes sense.
7567 @item @code{replacement} (default: @code{#f})
7568 This must be either @code{#f} or a package object that will be used as a
7569 @dfn{replacement} for this package. @xref{Security Updates, grafts},
7572 @item @code{synopsis}
7573 A one-line description of the package.
7575 @item @code{description}
7576 A more elaborate description of the package, as a string in Texinfo
7579 @item @code{license}
7580 @cindex license, of packages
7581 The license of the package; a value from @code{(guix licenses)},
7582 or a list of such values.
7584 @item @code{home-page}
7585 The URL to the home-page of the package, as a string.
7587 @item @code{supported-systems} (default: @code{%supported-systems})
7588 The list of systems supported by the package, as strings of the form
7589 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
7591 @item @code{location} (default: source location of the @code{package} form)
7592 The source location of the package. It is useful to override this when
7593 inheriting from another package, in which case this field is not
7594 automatically corrected.
7598 @deffn {Scheme Syntax} this-package
7599 When used in the @emph{lexical scope} of a package field definition, this
7600 identifier resolves to the package being defined.
7602 The example below shows how to add a package as a native input of itself when
7610 ;; When cross-compiled, Guile, for example, depends on
7611 ;; a native version of itself. Add it here.
7612 (native-inputs (if (%current-target-system)
7617 It is an error to refer to @code{this-package} outside a package definition.
7620 The following helper procedures are provided to help deal with package
7623 @deffn {Scheme Procedure} lookup-package-input @var{package} @var{name}
7624 @deffnx {Scheme Procedure} lookup-package-native-input @var{package} @var{name}
7625 @deffnx {Scheme Procedure} lookup-package-propagated-input @var{package} @var{name}
7626 @deffnx {Scheme Procedure} lookup-package-direct-input @var{package} @var{name}
7627 Look up @var{name} among @var{package}'s inputs (or native, propagated,
7628 or direct inputs). Return it if found, @code{#f} otherwise.
7630 @var{name} is the name of a package depended on. Here's how you might
7634 (use-modules (guix packages) (gnu packages base))
7636 (lookup-package-direct-input coreutils "gmp")
7637 @result{} #<package gmp@@6.2.1 @dots{}>
7640 In this example we obtain the @code{gmp} package that is among the
7641 direct inputs of @code{coreutils}.
7644 @cindex development inputs, of a package
7645 @cindex implicit inputs, of a package
7646 Sometimes you will want to obtain the list of inputs needed to
7647 @emph{develop} a package---all the inputs that are visible when the
7648 package is compiled. This is what the @code{package-development-inputs}
7651 @deffn {Scheme Procedure} package-development-inputs @var{package} @
7652 [@var{system}] [#:target #f]
7653 Return the list of inputs required by @var{package} for development
7654 purposes on @var{system}. When @var{target} is true, return the inputs
7655 needed to cross-compile @var{package} from @var{system} to
7656 @var{target}, where @var{target} is a triplet such as
7657 @code{"aarch64-linux-gnu"}.
7659 Note that the result includes both explicit inputs and implicit
7660 inputs---inputs automatically added by the build system (@pxref{Build
7661 Systems}). Let us take the @code{hello} package to illustrate that:
7664 (use-modules (gnu packages base) (guix packages))
7667 @result{} #<package hello@@2.10 gnu/packages/base.scm:79 7f585d4f6790>
7669 (package-direct-inputs hello)
7672 (package-development-inputs hello)
7673 @result{} (("source" @dots{}) ("tar" #<package tar@@1.32 @dots{}>) @dots{})
7676 In this example, @code{package-direct-inputs} returns the empty list,
7677 because @code{hello} has zero explicit dependencies. Conversely,
7678 @code{package-development-inputs} includes inputs implicitly added by
7679 @code{gnu-build-system} that are required to build @code{hello}: tar,
7680 gzip, GCC, libc, Bash, and more. To visualize it, @command{guix graph
7681 hello} would show you explicit inputs, whereas @command{guix graph -t
7682 bag hello} would include implicit inputs (@pxref{Invoking guix graph}).
7685 Because packages are regular Scheme objects that capture a complete
7686 dependency graph and associated build procedures, it is often useful to
7687 write procedures that take a package and return a modified version
7688 thereof according to some parameters. Below are a few examples.
7690 @cindex tool chain, choosing a package's tool chain
7691 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
7692 Return a variant of @var{package} that uses @var{toolchain} instead of
7693 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
7694 inputs (label/package tuples) providing equivalent functionality, such
7695 as the @code{gcc-toolchain} package.
7697 The example below returns a variant of the @code{hello} package built
7698 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
7699 GNU C Library) instead of the default tool chain:
7702 (let ((toolchain (specification->package "gcc-toolchain@@10")))
7703 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
7706 The build tool chain is part of the @dfn{implicit inputs} of
7707 packages---it's usually not listed as part of the various ``inputs''
7708 fields and is instead pulled in by the build system. Consequently, this
7709 procedure works by changing the build system of @var{package} so that it
7710 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
7711 for more on build systems.
7714 @node origin Reference
7715 @subsection @code{origin} Reference
7717 This section documents @dfn{origins}. An @code{origin} declaration
7718 specifies data that must be ``produced''---downloaded, usually---and
7719 whose content hash is known in advance. Origins are primarily used to
7720 represent the source code of packages (@pxref{Defining Packages}). For
7721 that reason, the @code{origin} form allows you to declare patches to
7722 apply to the original source code as well as code snippets to modify it.
7724 @deftp {Data Type} origin
7725 This is the data type representing a source code origin.
7729 An object containing the URI of the source. The object type depends on
7730 the @code{method} (see below). For example, when using the
7731 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
7732 values are: a URL represented as a string, or a list thereof.
7734 @cindex fixed-output derivations, for download
7736 A monadic procedure that handles the given URI@. The procedure must
7737 accept at least three arguments: the value of the @code{uri} field and
7738 the hash algorithm and hash value specified by the @code{hash} field.
7739 It must return a store item or a derivation in the store monad
7740 (@pxref{The Store Monad}); most methods return a fixed-output derivation
7741 (@pxref{Derivations}).
7743 Commonly used methods include @code{url-fetch}, which fetches data from
7744 a URL, and @code{git-fetch}, which fetches data from a Git repository
7748 A bytevector containing the SHA-256 hash of the source. This is
7749 equivalent to providing a @code{content-hash} SHA256 object in the
7750 @code{hash} field described below.
7753 The @code{content-hash} object of the source---see below for how to use
7754 @code{content-hash}.
7756 You can obtain this information using @code{guix download}
7757 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
7760 @item @code{file-name} (default: @code{#f})
7761 The file name under which the source code should be saved. When this is
7762 @code{#f}, a sensible default value will be used in most cases. In case
7763 the source is fetched from a URL, the file name from the URL will be
7764 used. For version control checkouts, it is recommended to provide the
7765 file name explicitly because the default is not very descriptive.
7767 @item @code{patches} (default: @code{'()})
7768 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
7769 file-like objects}) pointing to patches to be applied to the source.
7771 This list of patches must be unconditional. In particular, it cannot
7772 depend on the value of @code{%current-system} or
7773 @code{%current-target-system}.
7775 @item @code{snippet} (default: @code{#f})
7776 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
7777 in the source directory. This is a convenient way to modify the source,
7778 sometimes more convenient than a patch.
7780 @item @code{patch-flags} (default: @code{'("-p1")})
7781 A list of command-line flags that should be passed to the @code{patch}
7784 @item @code{patch-inputs} (default: @code{#f})
7785 Input packages or derivations to the patching process. When this is
7786 @code{#f}, the usual set of inputs necessary for patching are provided,
7787 such as GNU@tie{}Patch.
7789 @item @code{modules} (default: @code{'()})
7790 A list of Guile modules that should be loaded during the patching
7791 process and while running the code in the @code{snippet} field.
7793 @item @code{patch-guile} (default: @code{#f})
7794 The Guile package that should be used in the patching process. When
7795 this is @code{#f}, a sensible default is used.
7799 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
7800 Construct a content hash object for the given @var{algorithm}, and with
7801 @var{value} as its hash value. When @var{algorithm} is omitted, assume
7802 it is @code{sha256}.
7804 @var{value} can be a literal string, in which case it is base32-decoded,
7805 or it can be a bytevector.
7807 The following forms are all equivalent:
7810 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
7811 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
7813 (content-hash (base32
7814 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
7815 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
7819 Technically, @code{content-hash} is currently implemented as a macro.
7820 It performs sanity checks at macro-expansion time, when possible, such
7821 as ensuring that @var{value} has the right size for @var{algorithm}.
7824 As we have seen above, how exactly the data an origin refers to is
7825 retrieved is determined by its @code{method} field. The @code{(guix
7826 download)} module provides the most common method, @code{url-fetch},
7829 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
7830 [name] [#:executable? #f]
7831 Return a fixed-output derivation that fetches data from @var{url} (a
7832 string, or a list of strings denoting alternate URLs), which is expected
7833 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
7834 the file name is the base name of URL; optionally, @var{name} can
7835 specify a different file name. When @var{executable?} is true, make the
7836 downloaded file executable.
7838 When one of the URL starts with @code{mirror://}, then its host part is
7839 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
7841 Alternatively, when URL starts with @code{file://}, return the
7842 corresponding file name in the store.
7845 Likewise, the @code{(guix git-download)} module defines the
7846 @code{git-fetch} origin method, which fetches data from a Git version
7847 control repository, and the @code{git-reference} data type to describe
7848 the repository and revision to fetch.
7850 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
7851 Return a fixed-output derivation that fetches @var{ref}, a
7852 @code{<git-reference>} object. The output is expected to have recursive
7853 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
7854 the file name, or a generic name if @code{#f}.
7857 @deftp {Data Type} git-reference
7858 This data type represents a Git reference for @code{git-fetch} to
7863 The URL of the Git repository to clone.
7866 This string denotes either the commit to fetch (a hexadecimal string),
7867 or the tag to fetch. You can also use a ``short'' commit ID or a
7868 @command{git describe} style identifier such as
7869 @code{v1.0.1-10-g58d7909c97}.
7871 @item @code{recursive?} (default: @code{#f})
7872 This Boolean indicates whether to recursively fetch Git sub-modules.
7875 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
7880 (url "https://git.savannah.gnu.org/git/hello.git")
7884 This is equivalent to the reference below, which explicitly names the
7889 (url "https://git.savannah.gnu.org/git/hello.git")
7890 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
7894 For Mercurial repositories, the module @code{(guix hg-download)} defines
7895 the @code{hg-fetch} origin method and @code{hg-reference} data type for
7896 support of the Mercurial version control system.
7898 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
7900 Return a fixed-output derivation that fetches @var{ref}, a
7901 @code{<hg-reference>} object. The output is expected to have recursive
7902 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
7903 the file name, or a generic name if @code{#false}.
7906 @node Defining Package Variants
7907 @section Defining Package Variants
7909 @cindex customizing packages
7910 @cindex variants, of packages
7911 One of the nice things with Guix is that, given a package definition,
7912 you can easily @emph{derive} variants of that package---for a different
7913 upstream version, with different dependencies, different compilation
7914 options, and so on. Some of these custom packages can be defined
7915 straight from the command line (@pxref{Package Transformation Options}).
7916 This section describes how to define package variants in code. This can
7917 be useful in ``manifests'' (@pxref{Writing Manifests})
7918 and in your own package collection
7919 (@pxref{Creating a Channel}), among others!
7921 @cindex inherit, for package definitions
7922 As discussed earlier, packages are first-class objects in the Scheme
7923 language. The @code{(guix packages)} module provides the @code{package}
7924 construct to define new package objects (@pxref{package Reference}).
7925 The easiest way to define a package variant is using the @code{inherit}
7926 keyword together with @code{package}. This allows you to inherit from a
7927 package definition while overriding the fields you want.
7929 For example, given the @code{hello} variable, which contains a
7930 definition for the current version of GNU@tie{}Hello, here's how you
7931 would define a variant for version 2.2 (released in 2006, it's
7935 (use-modules (gnu packages base)) ;for 'hello'
7943 (uri (string-append "mirror://gnu/hello/hello-" version
7947 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
7950 The example above corresponds to what the @option{--with-source} package
7951 transformation option does. Essentially @code{hello-2.2} preserves all
7952 the fields of @code{hello}, except @code{version} and @code{source},
7953 which it overrides. Note that the original @code{hello} variable is
7954 still there, in the @code{(gnu packages base)} module, unchanged. When
7955 you define a custom package like this, you are really @emph{adding} a
7956 new package definition; the original one remains available.
7958 You can just as well define variants with a different set of
7959 dependencies than the original package. For example, the default
7960 @code{gdb} package depends on @code{guile}, but since that is an
7961 optional dependency, you can define a variant that removes that
7965 (use-modules (gnu packages gdb)) ;for 'gdb'
7967 (define gdb-sans-guile
7970 (inputs (modify-inputs (package-inputs gdb)
7971 (delete "guile")))))
7974 The @code{modify-inputs} form above removes the @code{"guile"} package
7975 from the @code{inputs} field of @code{gdb}. The @code{modify-inputs}
7976 macro is a helper that can prove useful anytime you want to remove, add,
7977 or replace package inputs.
7979 @deffn {Scheme Syntax} modify-inputs @var{inputs} @var{clauses}
7980 Modify the given package inputs, as returned by @code{package-inputs} & co.,
7981 according to the given clauses. Each clause must have one of the
7985 @item (delete @var{name}@dots{})
7986 Delete from the inputs packages with the given @var{name}s (strings).
7988 @item (append @var{package}@dots{})
7989 Add @var{package}s to the end of the input list.
7991 @item (prepend @var{package}@dots{})
7992 Add @var{package}s to the front of the input list.
7995 The example below removes the GMP and ACL inputs of Coreutils and adds
7996 libcap to the back of the input list:
7999 (modify-inputs (package-inputs coreutils)
8000 (delete "gmp" "acl")
8004 The example below replaces the @code{guile} package from the inputs of
8005 @code{guile-redis} with @code{guile-2.2}:
8008 (modify-inputs (package-inputs guile-redis)
8009 (replace "guile" guile-2.2))
8012 The last type of clause is @code{prepend}, to add inputs to the front of
8016 In some cases, you may find it useful to write functions
8017 (``procedures'', in Scheme parlance) that return a package based on some
8018 parameters. For example, consider the @code{luasocket} library for the
8019 Lua programming language. We want to create @code{luasocket} packages
8020 for major versions of Lua. One way to do that is to define a procedure
8021 that takes a Lua package and returns a @code{luasocket} package that
8025 (define (make-lua-socket name lua)
8026 ;; Return a luasocket package built with LUA.
8030 ;; several fields omitted
8032 (synopsis "Socket library for Lua")))
8034 (define-public lua5.1-socket
8035 (make-lua-socket "lua5.1-socket" lua-5.1))
8037 (define-public lua5.2-socket
8038 (make-lua-socket "lua5.2-socket" lua-5.2))
8041 Here we have defined packages @code{lua5.1-socket} and
8042 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
8043 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
8044 more info on procedures. Having top-level public definitions for these
8045 two packages means that they can be referred to from the command line
8046 (@pxref{Package Modules}).
8048 @cindex package transformations
8049 These are pretty simple package variants. As a convenience, the
8050 @code{(guix transformations)} module provides a high-level interface
8051 that directly maps to the more sophisticated package transformation
8052 options (@pxref{Package Transformation Options}):
8054 @deffn {Scheme Procedure} options->transformation @var{opts}
8055 Return a procedure that, when passed an object to build (package,
8056 derivation, etc.), applies the transformations specified by @var{opts} and returns
8057 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
8060 ((with-branch . "guile-gcrypt=master")
8061 (without-tests . "libgcrypt"))
8064 Each symbol names a transformation and the corresponding string is an argument
8065 to that transformation.
8068 For instance, a manifest equivalent to this command:
8072 --with-branch=guile-gcrypt=master \
8073 --with-debug-info=zlib
8077 ... would look like this:
8080 (use-modules (guix transformations))
8083 ;; The package transformation procedure.
8084 (options->transformation
8085 '((with-branch . "guile-gcrypt=master")
8086 (with-debug-info . "zlib"))))
8089 (list (transform (specification->package "guix"))))
8092 @cindex input rewriting
8093 @cindex dependency graph rewriting
8094 The @code{options->transformation} procedure is convenient, but it's
8095 perhaps also not as flexible as you may like. How is it implemented?
8096 The astute reader probably noticed that most package transformation
8097 options go beyond the superficial changes shown in the first examples of
8098 this section: they involve @dfn{input rewriting}, whereby the dependency
8099 graph of a package is rewritten by replacing specific inputs by others.
8101 Dependency graph rewriting, for the purposes of swapping packages in the
8102 graph, is what the @code{package-input-rewriting} procedure in
8103 @code{(guix packages)} implements.
8105 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
8106 [@var{rewrite-name}] [#:deep? #t]
8107 Return a procedure that, when passed a package, replaces its direct and
8108 indirect dependencies, including implicit inputs when @var{deep?} is
8109 true, according to @var{replacements}. @var{replacements} is a list of
8110 package pairs; the first element of each pair is the package to replace,
8111 and the second one is the replacement.
8113 Optionally, @var{rewrite-name} is a one-argument procedure that takes
8114 the name of a package and returns its new name after rewrite.
8118 Consider this example:
8121 (define libressl-instead-of-openssl
8122 ;; This is a procedure to replace OPENSSL by LIBRESSL,
8124 (package-input-rewriting `((,openssl . ,libressl))))
8126 (define git-with-libressl
8127 (libressl-instead-of-openssl git))
8131 Here we first define a rewriting procedure that replaces @var{openssl}
8132 with @var{libressl}. Then we use it to define a @dfn{variant} of the
8133 @var{git} package that uses @var{libressl} instead of @var{openssl}.
8134 This is exactly what the @option{--with-input} command-line option does
8135 (@pxref{Package Transformation Options, @option{--with-input}}).
8137 The following variant of @code{package-input-rewriting} can match packages to
8138 be replaced by name rather than by identity.
8140 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
8141 Return a procedure that, given a package, applies the given
8142 @var{replacements} to all the package graph, including implicit inputs
8143 unless @var{deep?} is false. @var{replacements} is a list of
8144 spec/procedures pair; each spec is a package specification such as
8145 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
8146 package and returns a replacement for that package.
8149 The example above could be rewritten this way:
8152 (define libressl-instead-of-openssl
8153 ;; Replace all the packages called "openssl" with LibreSSL.
8154 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
8157 The key difference here is that, this time, packages are matched by spec and
8158 not by identity. In other words, any package in the graph that is called
8159 @code{openssl} will be replaced.
8161 A more generic procedure to rewrite a package dependency graph is
8162 @code{package-mapping}: it supports arbitrary changes to nodes in the
8165 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
8166 Return a procedure that, given a package, applies @var{proc} to all the packages
8167 depended on and returns the resulting package. The procedure stops recursion
8168 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
8169 applied to implicit inputs as well.
8172 @node Writing Manifests
8173 @section Writing Manifests
8176 @cindex bill of materials (manifests)
8177 @command{guix} commands let you specify package lists on the command
8178 line. This is convenient, but as the command line becomes longer and
8179 less trivial, it quickly becomes more convenient to have that package
8180 list in what we call a @dfn{manifest}. A manifest is some sort of a
8181 ``bill of materials'' that defines a package set. You would typically
8182 come up with a code snippet that builds the manifest, store it in a
8183 file, say @file{manifest.scm}, and then pass that file to the
8184 @option{-m} (or @option{--manifest}) option that many @command{guix}
8185 commands support. For example, here's what a manifest for a simple
8186 package set might look like:
8189 ;; Manifest for three packages.
8190 (specifications->manifest '("gcc-toolchain" "make" "git"))
8193 Once you have that manifest, you can pass it, for example, to
8194 @command{guix package} to install just those three packages to your
8195 profile (@pxref{profile-manifest, @option{-m} option of @command{guix
8199 guix package -m manifest.scm
8203 ... or you can pass it to @command{guix shell} (@pxref{shell-manifest,
8204 @command{-m} option of @command{guix shell}}) to spawn an ephemeral
8208 guix shell -m manifest.scm
8212 ... or you can pass it to @command{guix pack} in pretty much the same
8213 way (@pxref{pack-manifest, @option{-m} option of @command{guix pack}}).
8214 You can store the manifest under version control, share it with others
8215 so they can easily get set up, etc.
8217 But how do you write your first manifest? To get started, maybe you'll
8218 want to write a manifest that mirrors what you already have in a
8219 profile. Rather than start from a blank page, @command{guix package}
8220 can generate a manifest for you (@pxref{export-manifest, @command{guix
8221 package --export-manifest}}):
8224 # Write to 'manifest.scm' a manifest corresponding to the
8225 # default profile, ~/.guix-profile.
8226 guix package --export-manifest > manifest.scm
8229 Or maybe you'll want to ``translate'' command-line arguments into a
8230 manifest. In that case, @command{guix shell} can help
8231 (@pxref{shell-export-manifest, @command{guix shell --export-manifest}}):
8234 # Write a manifest for the packages specified on the command line.
8235 guix shell --export-manifest gcc-toolchain make git > manifest.scm
8238 In both cases, the @option{--export-manifest} option tries hard to
8239 generate a faithful manifest; in particular, it takes package
8240 transformation options into account (@pxref{Package Transformation
8244 Manifests are @emph{symbolic}: they refer to packages of the channels
8245 @emph{currently in use} (@pxref{Channels}). In the example above,
8246 @code{gcc-toolchain} might refer to version 11 today, but it might refer
8247 to version 13 two years from now.
8249 If you want to ``pin'' your software environment to specific package
8250 versions and variants, you need an additional piece of information: the
8251 list of channel revisions in use, as returned by @command{guix
8252 describe}. @xref{Replicating Guix}, for more information.
8255 Once you've obtained your first manifest, perhaps you'll want to
8256 customize it. Since your manifest is code, you now have access to all
8257 the Guix programming interfaces!
8259 Let's assume you want a manifest to deploy a custom variant of GDB, the
8260 GNU Debugger, that does not depend on Guile, together with another
8261 package. Building on the example seen in the previous section
8262 (@pxref{Defining Package Variants}), you can write a manifest along
8266 (use-modules (guix packages)
8267 (gnu packages gdb) ;for 'gdb'
8268 (gnu packages version-control)) ;for 'git'
8270 ;; Define a variant of GDB without a dependency on Guile.
8271 (define gdb-sans-guile
8274 (inputs (modify-inputs (package-inputs gdb)
8275 (delete "guile")))))
8277 ;; Return a manifest containing that one package plus Git.
8278 (packages->manifest (list gdb-sans-guile git))
8281 Note that in this example, the manifest directly refers to the
8282 @code{gdb} and @code{git} variables, which are bound to a @code{package}
8283 object (@pxref{package Reference}), instead of calling
8284 @code{specifications->manifest} to look up packages by name as we did
8285 before. The @code{use-modules} form at the top lets us access the core
8286 package interface (@pxref{Defining Packages}) and the modules that
8287 define @code{gdb} and @code{git} (@pxref{Package Modules}). Seamlessly,
8288 we're weaving all this together---the possibilities are endless, unleash
8291 The data type for manifests as well as supporting procedures are defined
8292 in the @code{(guix profiles)} module, which is automatically available
8293 to code passed to @option{-m}. The reference follows.
8295 @deftp {Data Type} manifest
8296 Data type representing a manifest.
8298 It currently has one field:
8302 This must be a list of @code{manifest-entry} records---see below.
8306 @deftp {Data Type} manifest-entry
8307 Data type representing a manifest entry. A manifest entry contains
8308 essential metadata: a name and version string, the object (usually a
8309 package) for that entry, the desired output (@pxref{Packages with
8310 Multiple Outputs}), and a number of optional pieces of information
8313 Most of the time, you won't build a manifest entry directly; instead,
8314 you will pass a package to @code{package->manifest-entry}, described
8315 below. In some unusual cases though, you might want to create manifest
8316 entries for things that are @emph{not} packages, as in this example:
8319 ;; Manually build a single manifest entry for a non-package object.
8320 (let ((hello (program-file "hello" #~(display "Hi!"))))
8325 (computed-file "hello-directory"
8326 #~(let ((bin (string-append #$output "/bin")))
8327 (mkdir #$output) (mkdir bin)
8329 (string-append bin "/hello")))))))
8332 The available fields are the following:
8336 @itemx @code{version}
8337 Name and version string for this entry.
8340 A package or other file-like object (@pxref{G-Expressions, file-like
8343 @item @code{output} (default: @code{"out"})
8344 Output of @code{item} to use, in case @code{item} has multiple outputs
8345 (@pxref{Packages with Multiple Outputs}).
8347 @item @code{dependencies} (default: @code{'()})
8348 List of manifest entries this entry depends on. When building a
8349 profile, dependencies are added to the profile.
8351 Typically, the propagated inputs of a package (@pxref{package Reference,
8352 @code{propagated-inputs}}) end up having a corresponding manifest entry
8353 in among the dependencies of the package's own manifest entry.
8355 @item @code{search-paths} (default: @code{'()})
8356 The list of search path specifications honored by this entry
8357 (@pxref{Search Paths}).
8359 @item @code{properties} (default: @code{'()})
8360 List of symbol/value pairs. When building a profile, those properties
8363 This can be used to piggyback additional metadata---e.g., the
8364 transformations applied to a package (@pxref{Package Transformation
8367 @item @code{parent} (default: @code{(delay #f)})
8368 A promise pointing to the ``parent'' manifest entry.
8370 This is used as a hint to provide context when reporting an error
8371 related to a manifest entry coming from a @code{dependencies} field.
8375 @deffn {Scheme Procedure} concatenate-manifests @var{lst}
8376 Concatenate the manifests listed in @var{lst} and return the resulting
8380 @c TODO: <manifest-pattern>, manifest-lookup, manifest-remove, etc.
8382 @deffn {Scheme Procedure} package->manifest-entry @var{package} @
8383 [@var{output}] [#:properties]
8384 Return a manifest entry for the @var{output} of package @var{package},
8385 where @var{output} defaults to @code{"out"}, and with the given
8386 @var{properties}. By default @var{properties} is the empty list or, if
8387 one or more package transformations were applied to @var{package}, it is
8388 an association list representing those transformations, suitable as an
8389 argument to @code{options->transformation} (@pxref{Defining Package
8390 Variants, @code{options->transformation}}).
8392 The code snippet below builds a manifest with an entry for the default
8393 output and the @code{send-email} output of the @code{git} package:
8396 (use-modules (gnu packages version-control))
8398 (manifest (list (package->manifest-entry git)
8399 (package->manifest-entry git "send-email")))
8403 @deffn {Scheme Procedure} packages->manifest @var{packages}
8404 Return a list of manifest entries, one for each item listed in
8405 @var{packages}. Elements of @var{packages} can be either package
8406 objects or package/string tuples denoting a specific output of a
8409 Using this procedure, the manifest above may be rewritten more
8413 (use-modules (gnu packages version-control))
8415 (packages->manifest (list git `(,git "send-email")))
8419 @anchor{package-development-manifest}
8420 @deffn {Scheme Procedure} package->development-manifest @var{package} @
8421 [@var{system}] [#:target]
8422 Return a manifest for the @dfn{development inputs} of @var{package} for
8423 @var{system}, optionally when cross-compiling to @var{target}.
8424 Development inputs include both explicit and implicit inputs of
8427 Like the @option{-D} option of @command{guix shell}
8428 (@pxref{shell-development-option, @command{guix shell -D}}), the
8429 resulting manifest describes the environment in which one can develop
8430 @var{package}. For example, suppose you're willing to set up a
8431 development environment for Inkscape, with the addition of Git for
8432 version control; you can describe that ``bill of materials'' with the
8436 (use-modules (gnu packages inkscape) ;for 'inkscape'
8437 (gnu packages version-control)) ;for 'git'
8439 (concatenate-manifests
8440 (list (package->development-manifest inkscape)
8441 (packages->manifest (list git))))
8444 In this example, the development manifest that
8445 @code{package->development-manifest} returns includes the compiler
8446 (GCC), the many supporting libraries (Boost, GLib, GTK, etc.), and a
8447 couple of additional development tools---these are the dependencies
8448 @command{guix show inkscape} lists.
8451 @c TODO: Move (gnu packages) interface to a section of its own.
8453 Last, the @code{(gnu packages)} module provides higher-level facilities
8454 to build manifests. In particular, it lets you look up packages by
8457 @deffn {Scheme Procedure} specifications->manifest @var{specs}
8458 Given @var{specs}, a list of specifications such as @code{"emacs@@25.2"}
8459 or @code{"guile:debug"}, return a manifest. Specs have the format that
8460 command-line tools such as @command{guix install} and @command{guix
8461 package} understand (@pxref{Invoking guix package}).
8463 As an example, it lets you rewrite the Git manifest that we saw earlier
8467 (specifications->manifest '("git" "git:send-email"))
8470 Notice that we do not need to worry about @code{use-modules}, importing
8471 the right set of modules, and referring to the right variables.
8472 Instead, we directly refer to packages in the same way as on the command
8473 line, which can often be more convenient.
8476 @c TODO: specifications->package, etc.
8480 @section Build Systems
8482 @cindex build system
8483 Each package definition specifies a @dfn{build system} and arguments for
8484 that build system (@pxref{Defining Packages}). This @code{build-system}
8485 field represents the build procedure of the package, as well as implicit
8486 dependencies of that build procedure.
8488 Build systems are @code{<build-system>} objects. The interface to
8489 create and manipulate them is provided by the @code{(guix build-system)}
8490 module, and actual build systems are exported by specific modules.
8492 @cindex bag (low-level package representation)
8493 Under the hood, build systems first compile package objects to
8494 @dfn{bags}. A @dfn{bag} is like a package, but with less
8495 ornamentation---in other words, a bag is a lower-level representation of
8496 a package, which includes all the inputs of that package, including some
8497 that were implicitly added by the build system. This intermediate
8498 representation is then compiled to a derivation (@pxref{Derivations}).
8499 The @code{package-with-c-toolchain} is an example of a way to change the
8500 implicit inputs that a package's build system pulls in (@pxref{package
8501 Reference, @code{package-with-c-toolchain}}).
8503 Build systems accept an optional list of @dfn{arguments}. In package
8504 definitions, these are passed @i{via} the @code{arguments} field
8505 (@pxref{Defining Packages}). They are typically keyword arguments
8506 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
8507 Guile Reference Manual}). The value of these arguments is usually
8508 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
8509 by the daemon (@pxref{Derivations}).
8511 The main build system is @code{gnu-build-system}, which implements the
8512 standard build procedure for GNU and many other packages. It
8513 is provided by the @code{(guix build-system gnu)} module.
8515 @defvr {Scheme Variable} gnu-build-system
8516 @code{gnu-build-system} represents the GNU Build System, and variants
8517 thereof (@pxref{Configuration, configuration and makefile conventions,,
8518 standards, GNU Coding Standards}).
8520 @cindex build phases
8521 In a nutshell, packages using it are configured, built, and installed with
8522 the usual @code{./configure && make && make check && make install}
8523 command sequence. In practice, a few additional steps are often needed.
8524 All these steps are split up in separate @dfn{phases}.
8525 @xref{Build Phases}, for more info on build phases and ways to customize
8528 In addition, this build system ensures that the ``standard'' environment
8529 for GNU packages is available. This includes tools such as GCC, libc,
8530 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
8531 build-system gnu)} module for a complete list). We call these the
8532 @dfn{implicit inputs} of a package, because package definitions do not
8533 have to mention them.
8535 This build system supports a number of keyword arguments, which can be
8536 passed @i{via} the @code{arguments} field of a package. Here are some
8537 of the main parameters:
8541 This argument specifies build-side code that evaluates to an alist of
8542 build phases. @xref{Build Phases}, for more information.
8544 @item #:configure-flags
8545 This is a list of flags (strings) passed to the @command{configure}
8546 script. @xref{Defining Packages}, for an example.
8549 This list of strings contains flags passed as arguments to
8550 @command{make} invocations in the @code{build}, @code{check}, and
8551 @code{install} phases.
8553 @item #:out-of-source?
8554 This Boolean, @code{#f} by default, indicates whether to run builds in a
8555 build directory separate from the source tree.
8557 When it is true, the @code{configure} phase creates a separate build
8558 directory, changes to that directory, and runs the @code{configure}
8559 script from there. This is useful for packages that require it, such as
8563 This Boolean, @code{#t} by default, indicates whether the @code{check}
8564 phase should run the package's test suite.
8567 This string, @code{"check"} by default, gives the name of the makefile
8568 target used by the @code{check} phase.
8570 @item #:parallel-build?
8571 @itemx #:parallel-tests?
8572 These Boolean values specify whether to build, respectively run the test
8573 suite, in parallel, with the @code{-j} flag of @command{make}. When
8574 they are true, @code{make} is passed @code{-j@var{n}}, where @var{n} is
8575 the number specified as the @option{--cores} option of
8576 @command{guix-daemon} or that of the @command{guix} client command
8577 (@pxref{Common Build Options, @option{--cores}}).
8579 @cindex RUNPATH, validation
8580 @item #:validate-runpath?
8581 This Boolean, @code{#t} by default, determines whether to ``validate''
8582 the @code{RUNPATH} of ELF binaries (@code{.so} shared libraries as well
8583 as executables) previously installed by the @code{install} phase.
8584 @xref{phase-validate-runpath, the @code{validate-runpath} phase}, for
8587 @item #:substitutable?
8588 This Boolean, @code{#t} by default, tells whether the package outputs
8589 should be substitutable---i.e., whether users should be able to obtain
8590 substitutes for them instead of building locally (@pxref{Substitutes}).
8592 @item #:allowed-references
8593 @itemx #:disallowed-references
8594 When true, these arguments must be a list of dependencies that must not
8595 appear among the references of the build results. If, upon build
8596 completion, some of these references are retained, the build process
8599 This is useful to ensure that a package does not erroneously keep a
8600 reference to some of it build-time inputs, in cases where doing so
8601 would, for example, unnecessarily increase its size (@pxref{Invoking
8605 Most other build systems support these keyword arguments.
8608 Other @code{<build-system>} objects are defined to support other
8609 conventions and tools used by free software packages. They inherit most
8610 of @code{gnu-build-system}, and differ mainly in the set of inputs
8611 implicitly added to the build process, and in the list of phases
8612 executed. Some of these build systems are listed below.
8614 @defvr {Scheme Variable} ant-build-system
8615 This variable is exported by @code{(guix build-system ant)}. It
8616 implements the build procedure for Java packages that can be built with
8617 @url{https://ant.apache.org/, Ant build tool}.
8619 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
8620 provided by the @code{icedtea} package to the set of inputs. Different
8621 packages can be specified with the @code{#:ant} and @code{#:jdk}
8622 parameters, respectively.
8624 When the original package does not provide a suitable Ant build file,
8625 the parameter @code{#:jar-name} can be used to generate a minimal Ant
8626 build file @file{build.xml} with tasks to build the specified jar
8627 archive. In this case the parameter @code{#:source-dir} can be used to
8628 specify the source sub-directory, defaulting to ``src''.
8630 The @code{#:main-class} parameter can be used with the minimal ant
8631 buildfile to specify the main class of the resulting jar. This makes the
8632 jar file executable. The @code{#:test-include} parameter can be used to
8633 specify the list of junit tests to run. It defaults to
8634 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
8635 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
8636 because abstract classes cannot be run as tests.
8638 The parameter @code{#:build-target} can be used to specify the Ant task
8639 that should be run during the @code{build} phase. By default the
8640 ``jar'' task will be run.
8644 @defvr {Scheme Variable} android-ndk-build-system
8645 @cindex Android distribution
8646 @cindex Android NDK build system
8647 This variable is exported by @code{(guix build-system android-ndk)}. It
8648 implements a build procedure for Android NDK (native development kit)
8649 packages using a Guix-specific build process.
8651 The build system assumes that packages install their public interface
8652 (header) files to the subdirectory @file{include} of the @code{out} output and
8653 their libraries to the subdirectory @file{lib} the @code{out} output.
8655 It's also assumed that the union of all the dependencies of a package
8656 has no conflicting files.
8658 For the time being, cross-compilation is not supported - so right now
8659 the libraries and header files are assumed to be host tools.
8663 @defvr {Scheme Variable} asdf-build-system/source
8664 @defvrx {Scheme Variable} asdf-build-system/sbcl
8665 @defvrx {Scheme Variable} asdf-build-system/ecl
8667 These variables, exported by @code{(guix build-system asdf)}, implement
8668 build procedures for Common Lisp packages using
8669 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
8670 definition facility for Common Lisp programs and libraries.
8672 The @code{asdf-build-system/source} system installs the packages in
8673 source form, and can be loaded using any common lisp implementation, via
8674 ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
8675 systems in the format which a particular implementation understands.
8676 These build systems can also be used to produce executable programs, or
8677 lisp images which contain a set of packages pre-loaded.
8679 The build system uses naming conventions. For binary packages, the
8680 package name should be prefixed with the lisp implementation, such as
8681 @code{sbcl-} for @code{asdf-build-system/sbcl}.
8683 Additionally, the corresponding source package should be labeled using
8684 the same convention as python packages (see @ref{Python Modules}), using
8685 the @code{cl-} prefix.
8687 In order to create executable programs and images, the build-side
8688 procedures @code{build-program} and @code{build-image} can be used.
8689 They should be called in a build phase after the
8690 @code{create-asdf-configuration} phase, so that the system which was
8691 just built can be used within the resulting image. @code{build-program}
8692 requires a list of Common Lisp expressions to be passed as the
8693 @code{#:entry-program} argument.
8695 By default, all the @file{.asd} files present in the sources are read to
8696 find system definitions. The @code{#:asd-files} parameter can be used
8697 to specify the list of @file{.asd} files to read. Furthermore, if the
8698 package defines a system for its tests in a separate file, it will be
8699 loaded before the tests are run if it is specified by the
8700 @code{#:test-asd-file} parameter. If it is not set, the files
8701 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
8702 and @code{test.asd} will be tried if they exist.
8704 If for some reason the package must be named in a different way than the
8705 naming conventions suggest, or if several systems must be compiled, the
8706 @code{#:asd-systems} parameter can be used to specify the list of system
8711 @defvr {Scheme Variable} cargo-build-system
8712 @cindex Rust programming language
8713 @cindex Cargo (Rust build system)
8714 This variable is exported by @code{(guix build-system cargo)}. It
8715 supports builds of packages using Cargo, the build tool of the
8716 @uref{https://www.rust-lang.org, Rust programming language}.
8718 It adds @code{rustc} and @code{cargo} to the set of inputs.
8719 A different Rust package can be specified with the @code{#:rust} parameter.
8721 Regular cargo dependencies should be added to the package definition similarly
8722 to other packages; those needed only at build time to native-inputs, others to
8723 inputs. If you need to add source-only crates then you should add them to via
8724 the @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
8725 spec can be a package or a source definition. Note that the spec must
8726 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
8727 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
8728 should be added to the package definition via the
8729 @code{#:cargo-development-inputs} parameter.
8731 In its @code{configure} phase, this build system will make any source inputs
8732 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
8733 parameters available to cargo. It will also remove an included
8734 @code{Cargo.lock} file to be recreated by @code{cargo} during the
8735 @code{build} phase. The @code{package} phase will run @code{cargo package}
8736 to create a source crate for future use. The @code{install} phase installs
8737 the binaries defined by the crate. Unless @code{install-source? #f} is
8738 defined it will also install a source crate repository of itself and unpacked
8739 sources, to ease in future hacking on rust packages.
8742 @defvr {Scheme Variable} chicken-build-system
8743 This variable is exported by @code{(guix build-system chicken)}. It
8744 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
8745 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
8746 gets compiled by a C compiler, in this case GCC.
8748 This build system adds @code{chicken} to the package inputs, as well as
8749 the packages of @code{gnu-build-system}.
8751 The build system can't (yet) deduce the egg's name automatically, so just like
8752 with @code{go-build-system} and its @code{#:import-path}, you should define
8753 @code{#:egg-name} in the package's @code{arguments} field.
8755 For example, if you are packaging the @code{srfi-1} egg:
8758 (arguments '(#:egg-name "srfi-1"))
8761 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
8762 because CHICKEN doesn't embed absolute references in compiled eggs.
8763 Test dependencies should go to @code{native-inputs}, as usual.
8766 @defvr {Scheme Variable} copy-build-system
8767 This variable is exported by @code{(guix build-system copy)}. It
8768 supports builds of simple packages that don't require much compiling,
8769 mostly just moving files around.
8771 It adds much of the @code{gnu-build-system} packages to the set of
8772 inputs. Because of this, the @code{copy-build-system} does not require
8773 all the boilerplate code often needed for the
8774 @code{trivial-build-system}.
8776 To further simplify the file installation process, an
8777 @code{#:install-plan} argument is exposed to let the packager specify
8778 which files go where. The install plan is a list of @code{(@var{source}
8779 @var{target} [@var{filters}])}. @var{filters} are optional.
8782 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
8784 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
8785 @item Otherwise install @var{source} as @var{target}.
8788 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
8789 the trailing slash of @var{target} is implied with the same meaning
8792 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
8793 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
8794 @code{#:exclude-regexp}, only select files are installed depending on
8795 the filters. Each filters is specified by a list of strings.
8797 @item With @code{#:include}, install all the files which the path suffix matches
8798 at least one of the elements in the given list.
8799 @item With @code{#:include-regexp}, install all the files which the
8800 subpaths match at least one of the regular expressions in the given
8802 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
8803 are the complement of their inclusion counterpart. Without @code{#:include} flags,
8804 install all files but those matching the exclusion filters.
8805 If both inclusions and exclusions are specified, the exclusions are done
8806 on top of the inclusions.
8809 In all cases, the paths relative to @var{source} are preserved within
8816 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
8817 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
8818 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
8819 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
8820 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
8821 @file{share/my-app/sub/file}.
8822 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
8823 @file{share/my-app/file}.
8828 @cindex Clojure (programming language)
8829 @cindex simple Clojure build system
8830 @defvr {Scheme Variable} clojure-build-system
8831 This variable is exported by @code{(guix build-system clojure)}. It implements
8832 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
8833 using plain old @code{compile} in Clojure. Cross-compilation is not supported
8836 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
8837 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
8838 @code{#:zip} parameters, respectively.
8840 A list of source directories, test directories and jar names can be specified
8841 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
8842 parameters, respectively. Compile directory and main class can be specified
8843 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
8844 Other parameters are documented below.
8846 This build system is an extension of @code{ant-build-system}, but with the
8847 following phases changed:
8852 This phase calls @code{compile} in Clojure to compile source files and runs
8853 @command{jar} to create jars from both source files and compiled files
8854 according to the include list and exclude list specified in
8855 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
8856 has priority over the include list. These lists consist of symbols
8857 representing Clojure libraries or the special keyword @code{#:all} representing
8858 all Clojure libraries found under the source directories. The parameter
8859 @code{#:omit-source?} decides if source should be included into the jars.
8862 This phase runs tests according to the include list and exclude list specified
8863 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
8864 meanings are analogous to that of @code{#:aot-include} and
8865 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
8866 stands for all Clojure libraries found under the test directories. The
8867 parameter @code{#:tests?} decides if tests should be run.
8870 This phase installs all jars built previously.
8873 Apart from the above, this build system also contains an additional phase:
8878 This phase installs all top-level files with base name matching
8879 @code{%doc-regex}. A different regex can be specified with the
8880 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
8881 directories specified in @code{#:doc-dirs} are installed as well.
8885 @defvr {Scheme Variable} cmake-build-system
8886 This variable is exported by @code{(guix build-system cmake)}. It
8887 implements the build procedure for packages using the
8888 @url{https://www.cmake.org, CMake build tool}.
8890 It automatically adds the @code{cmake} package to the set of inputs.
8891 Which package is used can be specified with the @code{#:cmake}
8894 The @code{#:configure-flags} parameter is taken as a list of flags
8895 passed to the @command{cmake} command. The @code{#:build-type}
8896 parameter specifies in abstract terms the flags passed to the compiler;
8897 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
8898 debugging information''), which roughly means that code is compiled with
8899 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
8902 @defvr {Scheme Variable} dune-build-system
8903 This variable is exported by @code{(guix build-system dune)}. It
8904 supports builds of packages using @uref{https://dune.build/, Dune}, a build
8905 tool for the OCaml programming language. It is implemented as an extension
8906 of the @code{ocaml-build-system} which is described below. As such, the
8907 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
8910 It automatically adds the @code{dune} package to the set of inputs.
8911 Which package is used can be specified with the @code{#:dune}
8914 There is no @code{configure} phase because dune packages typically don't
8915 need to be configured. The @code{#:build-flags} parameter is taken as a
8916 list of flags passed to the @code{dune} command during the build.
8918 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
8919 command instead of the more recent @code{dune} command while building
8920 a package. Its default value is @code{#f}.
8922 The @code{#:package} parameter can be passed to specify a package name, which
8923 is useful when a package contains multiple packages and you want to build
8924 only one of them. This is equivalent to passing the @code{-p} argument to
8929 @defvr {Scheme variable} elm-build-system
8930 This variable is exported by @code{(guix build-system elm)}. It implements a
8931 build procedure for @url{https://elm-lang.org, Elm} packages similar to
8934 The build system adds an Elm compiler package to the set of inputs. The
8935 default compiler package (currently @code{elm-sans-reactor}) can be overridden
8936 using the @code{#:elm} argument. Additionally, Elm packages needed by the
8937 build system itself are added as implicit inputs if they are not already
8938 present: to suppress this behavior, use the
8939 @code{#:implicit-elm-package-inputs?} argument, which is primarily useful for
8942 The @code{"dependencies"} and @code{"test-dependencies"} in an Elm package's
8943 @file{elm.json} file correspond to @code{propagated-inputs} and @code{inputs},
8946 Elm requires a particular structure for package names: @pxref{Elm Packages}
8947 for more details, including utilities provided by @code{(guix build-system
8950 There are currently a few noteworthy limitations to @code{elm-build-system}:
8954 The build system is focused on @dfn{packages} in the Elm sense of the word:
8955 Elm @dfn{projects} which declare @code{@{ "type": "package" @}} in their
8956 @file{elm.json} files. Using @code{elm-build-system} to build Elm
8957 @dfn{applications} (which declare @code{@{ "type": "application" @}}) is
8958 possible, but requires ad-hoc modifications to the build phases. For
8959 examples, see the definitions of the @code{elm-todomvc} example application and
8960 the @code{elm} package itself (because the front-end for the
8961 @samp{elm reactor} command is an Elm application).
8964 Elm supports multiple versions of a package coexisting simultaneously under
8965 @env{ELM_HOME}, but this does not yet work well with @code{elm-build-system}.
8966 This limitation primarily affects Elm applications, because they specify
8967 exact versions for their dependencies, whereas Elm packages specify supported
8968 version ranges. As a workaround, the example applications mentioned above use
8969 the @code{patch-application-dependencies} procedure provided by
8970 @code{(guix build elm-build-system)} to rewrite their @file{elm.json} files to
8971 refer to the package versions actually present in the build environment.
8972 Alternatively, Guix package transformations (@pxref{Defining Package
8973 Variants}) could be used to rewrite an application's entire dependency graph.
8976 We are not yet able to run tests for Elm projects because neither
8977 @url{https://github.com/mpizenberg/elm-test-rs, @command{elm-test-rs}} nor the
8978 Node.js-based @url{https://github.com/rtfeldman/node-test-runner,
8979 @command{elm-test}} runner has been packaged for Guix yet.
8983 @defvr {Scheme Variable} go-build-system
8984 This variable is exported by @code{(guix build-system go)}. It
8985 implements a build procedure for Go packages using the standard
8986 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
8987 Go build mechanisms}.
8989 The user is expected to provide a value for the key @code{#:import-path}
8990 and, in some cases, @code{#:unpack-path}. The
8991 @url{https://golang.org/doc/code.html#ImportPaths, import path}
8992 corresponds to the file system path expected by the package's build
8993 scripts and any referring packages, and provides a unique way to
8994 refer to a Go package. It is typically based on a combination of the
8995 package source code's remote URI and file system hierarchy structure. In
8996 some cases, you will need to unpack the package's source code to a
8997 different directory structure than the one indicated by the import path,
8998 and @code{#:unpack-path} should be used in such cases.
9000 Packages that provide Go libraries should install their source code into
9001 the built output. The key @code{#:install-source?}, which defaults to
9002 @code{#t}, controls whether or not the source code is installed. It can
9003 be set to @code{#f} for packages that only provide executable files.
9005 Packages can be cross-built, and if a specific architecture or operating
9006 system is desired then the keywords @code{#:goarch} and @code{#:goos}
9007 can be used to force the package to be built for that architecture and
9008 operating system. The combinations known to Go can be found
9009 @url{"https://golang.org/doc/install/source#environment", in their
9013 @defvr {Scheme Variable} glib-or-gtk-build-system
9014 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
9015 is intended for use with packages making use of GLib or GTK+.
9017 This build system adds the following two phases to the ones defined by
9018 @code{gnu-build-system}:
9021 @item glib-or-gtk-wrap
9022 The phase @code{glib-or-gtk-wrap} ensures that programs in
9023 @file{bin/} are able to find GLib ``schemas'' and
9024 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
9025 modules}. This is achieved by wrapping the programs in launch scripts
9026 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
9027 environment variables.
9029 It is possible to exclude specific package outputs from that wrapping
9030 process by listing their names in the
9031 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
9032 when an output is known not to contain any GLib or GTK+ binaries, and
9033 where wrapping would gratuitously add a dependency of that output on
9036 @item glib-or-gtk-compile-schemas
9037 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
9038 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
9039 GSettings schemas} of GLib are compiled. Compilation is performed by the
9040 @command{glib-compile-schemas} program. It is provided by the package
9041 @code{glib:bin} which is automatically imported by the build system.
9042 The @code{glib} package providing @command{glib-compile-schemas} can be
9043 specified with the @code{#:glib} parameter.
9046 Both phases are executed after the @code{install} phase.
9049 @defvr {Scheme Variable} guile-build-system
9050 This build system is for Guile packages that consist exclusively of Scheme
9051 code and that are so lean that they don't even have a makefile, let alone a
9052 @file{configure} script. It compiles Scheme code using @command{guild
9053 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
9054 installs the @file{.scm} and @file{.go} files in the right place. It also
9055 installs documentation.
9057 This build system supports cross-compilation by using the
9058 @option{--target} option of @samp{guild compile}.
9060 Packages built with @code{guile-build-system} must provide a Guile package in
9061 their @code{native-inputs} field.
9064 @defvr {Scheme Variable} julia-build-system
9065 This variable is exported by @code{(guix build-system julia)}. It
9066 implements the build procedure used by @uref{https://julialang.org/,
9067 julia} packages, which essentially is similar to running @samp{julia -e
9068 'using Pkg; Pkg.add(package)'} in an environment where
9069 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
9070 Tests are run by calling @code{/test/runtests.jl}.
9072 The Julia package name and uuid is read from the file
9073 @file{Project.toml}. These values can be overridden by passing the
9074 argument @code{#:julia-package-name} (which must be correctly
9075 capitalized) or @code{#:julia-package-uuid}.
9077 Julia packages usually manage their binary dependencies via
9078 @code{JLLWrappers.jl}, a Julia package that creates a module (named
9079 after the wrapped library followed by @code{_jll.jl}.
9081 To add the binary path @code{_jll.jl} packages, you need to patch the
9082 files under @file{src/wrappers/}, replacing the call to the macro
9083 @code{JLLWrappers.@@generate_wrapper_header}, adding as a second
9084 argument containing the store path the binary.
9086 As an example, in the MbedTLS Julia package, we add a build phase
9087 (@pxref{Build Phases}) to insert the absolute file name of the wrapped
9091 (add-after 'unpack 'override-binary-path
9092 (lambda* (#:key inputs #:allow-other-keys)
9093 (for-each (lambda (wrapper)
9094 (substitute* wrapper
9095 (("generate_wrapper_header.*")
9097 "generate_wrapper_header(\"MbedTLS\", \""
9098 (assoc-ref inputs "mbedtls-apache") "\")\n"))))
9099 ;; There's a Julia file for each platform, override them all.
9100 (find-files "src/wrappers/" "\\.jl$"))))
9103 Some older packages that aren't using @file{Project.toml} yet, will
9104 require this file to be created, too. It is internally done if the
9105 arguments @code{#:julia-package-name} and @code{#:julia-package-uuid}
9109 @defvr {Scheme Variable} maven-build-system
9110 This variable is exported by @code{(guix build-system maven)}. It implements
9111 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
9112 is a dependency and lifecycle management tool for Java. A user of Maven
9113 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
9114 When Maven does not have one of the dependencies or plugins in its repository,
9115 it will download them and use them to build the package.
9117 The maven build system ensures that maven will not try to download any
9118 dependency by running in offline mode. Maven will fail if a dependency is
9119 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
9120 modified to specify the version of dependencies and plugins that match the
9121 versions available in the guix build environment. Dependencies and plugins
9122 must be installed in the fake maven repository at @file{lib/m2}, and are
9123 symlinked into a proper repository before maven is run. Maven is instructed
9124 to use that repository for the build and installs built artifacts there.
9125 Changed files are copied to the @file{lib/m2} directory of the package output.
9127 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
9128 or let the build system use the default @file{pom.xml} file in the sources.
9130 In case you need to specify a dependency's version manually, you can use the
9131 @code{#:local-packages} argument. It takes an association list where the key
9132 is the groupId of the package and its value is an association list where the
9133 key is the artifactId of the package and its value is the version you want to
9134 override in the @file{pom.xml}.
9136 Some packages use dependencies or plugins that are not useful at runtime nor
9137 at build time in Guix. You can alter the @file{pom.xml} file to remove them
9138 using the @code{#:exclude} argument. Its value is an association list where
9139 the key is the groupId of the plugin or dependency you want to remove, and
9140 the value is a list of artifactId you want to remove.
9142 You can override the default @code{jdk} and @code{maven} packages with the
9143 corresponding argument, @code{#:jdk} and @code{#:maven}.
9145 The @code{#:maven-plugins} argument is a list of maven plugins used during
9146 the build, with the same format as the @code{inputs} fields of the package
9147 declaration. Its default value is @code{(default-maven-plugins)} which is
9151 @defvr {Scheme Variable} minetest-mod-build-system
9152 This variable is exported by @code{(guix build-system minetest)}. It
9153 implements a build procedure for @uref{https://www.minetest.net, Minetest}
9154 mods, which consists of copying Lua code, images and other resources to
9155 the location Minetest searches for mods. The build system also minimises
9156 PNG images and verifies that Minetest can load the mod without errors.
9159 @defvr {Scheme Variable} minify-build-system
9160 This variable is exported by @code{(guix build-system minify)}. It
9161 implements a minification procedure for simple JavaScript packages.
9163 It adds @code{uglify-js} to the set of inputs and uses it to compress
9164 all JavaScript files in the @file{src} directory. A different minifier
9165 package can be specified with the @code{#:uglify-js} parameter, but it
9166 is expected that the package writes the minified code to the standard
9169 When the input JavaScript files are not all located in the @file{src}
9170 directory, the parameter @code{#:javascript-files} can be used to
9171 specify a list of file names to feed to the minifier.
9174 @defvr {Scheme Variable} ocaml-build-system
9175 This variable is exported by @code{(guix build-system ocaml)}. It implements
9176 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
9177 of choosing the correct set of commands to run for each package. OCaml
9178 packages can expect many different commands to be run. This build system will
9181 When the package has a @file{setup.ml} file present at the top-level, it will
9182 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
9183 @code{ocaml setup.ml -install}. The build system will assume that this file
9184 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
9185 care of setting the prefix and enabling tests if they are not disabled. You
9186 can pass configure and build flags with the @code{#:configure-flags} and
9187 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
9188 set of flags used to enable tests. The @code{#:use-make?} key can be used to
9189 bypass this system in the build and install phases.
9191 When the package has a @file{configure} file, it is assumed that it is a
9192 hand-made configure script that requires a different argument format than
9193 in the @code{gnu-build-system}. You can add more flags with the
9194 @code{#:configure-flags} key.
9196 When the package has a @file{Makefile} file (or @code{#:use-make?} is
9197 @code{#t}), it will be used and more flags can be passed to the build and
9198 install phases with the @code{#:make-flags} key.
9200 Finally, some packages do not have these files and use a somewhat standard
9201 location for its build system. In that case, the build system will run
9202 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
9203 providing the path to the required findlib module. Additional flags can
9204 be passed via the @code{#:build-flags} key. Install is taken care of by
9205 @command{opam-installer}. In this case, the @code{opam} package must
9206 be added to the @code{native-inputs} field of the package definition.
9208 Note that most OCaml packages assume they will be installed in the same
9209 directory as OCaml, which is not what we want in guix. In particular, they
9210 will install @file{.so} files in their module's directory, which is usually
9211 fine because it is in the OCaml compiler directory. In guix though, these
9212 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
9213 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
9214 @file{.so} libraries should be installed.
9217 @defvr {Scheme Variable} python-build-system
9218 This variable is exported by @code{(guix build-system python)}. It
9219 implements the more or less standard build procedure used by Python
9220 packages, which consists in running @code{python setup.py build} and
9221 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
9223 For packages that install stand-alone Python programs under @code{bin/},
9224 it takes care of wrapping these programs so that their
9225 @env{GUIX_PYTHONPATH} environment variable points to all the Python
9226 libraries they depend on.
9228 Which Python package is used to perform the build can be specified with
9229 the @code{#:python} parameter. This is a useful way to force a package
9230 to be built for a specific version of the Python interpreter, which
9231 might be necessary if the package is only compatible with a single
9232 interpreter version.
9234 By default guix calls @code{setup.py} under control of
9235 @code{setuptools}, much like @command{pip} does. Some packages are not
9236 compatible with setuptools (and pip), thus you can disable this by
9237 setting the @code{#:use-setuptools?} parameter to @code{#f}.
9239 If a @code{"python"} output is available, the package is installed into it
9240 instead of the default @code{"out"} output. This is useful for packages that
9241 include a Python package as only a part of the software, and thus want to
9242 combine the phases of @code{python-build-system} with another build system.
9243 Python bindings are a common usecase.
9247 @defvr {Scheme Variable} perl-build-system
9248 This variable is exported by @code{(guix build-system perl)}. It
9249 implements the standard build procedure for Perl packages, which either
9250 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
9251 followed by @code{Build} and @code{Build install}; or in running
9252 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
9253 @code{make} and @code{make install}, depending on which of
9254 @code{Build.PL} or @code{Makefile.PL} is present in the package
9255 distribution. Preference is given to the former if both @code{Build.PL}
9256 and @code{Makefile.PL} exist in the package distribution. This
9257 preference can be reversed by specifying @code{#t} for the
9258 @code{#:make-maker?} parameter.
9260 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
9261 passes flags specified by the @code{#:make-maker-flags} or
9262 @code{#:module-build-flags} parameter, respectively.
9264 Which Perl package is used can be specified with @code{#:perl}.
9267 @defvr {Scheme Variable} renpy-build-system
9268 This variable is exported by @code{(guix build-system renpy)}. It implements
9269 the more or less standard build procedure used by Ren'py games, which consists
9270 of loading @code{#:game} once, thereby creating bytecode for it.
9272 It further creates a wrapper script in @code{bin/} and a desktop entry in
9273 @code{share/applications}, both of which can be used to launch the game.
9275 Which Ren'py package is used can be specified with @code{#:renpy}.
9276 Games can also be installed in outputs other than ``out'' by using
9280 @defvr {Scheme Variable} qt-build-system
9281 This variable is exported by @code{(guix build-system qt)}. It
9282 is intended for use with applications using Qt or KDE.
9284 This build system adds the following two phases to the ones defined by
9285 @code{cmake-build-system}:
9289 The phase @code{check-setup} prepares the environment for running
9290 the checks as commonly used by Qt test programs.
9291 For now this only sets some environment variables:
9292 @code{QT_QPA_PLATFORM=offscreen},
9293 @code{DBUS_FATAL_WARNINGS=0} and
9294 @code{CTEST_OUTPUT_ON_FAILURE=1}.
9296 This phase is added before the @code{check} phase.
9297 It's a separate phase to ease adjusting if necessary.
9300 The phase @code{qt-wrap}
9301 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
9302 and output. In case some path is found, all programs in the output's
9303 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
9304 are wrapped in scripts defining the necessary environment variables.
9306 It is possible to exclude specific package outputs from that wrapping process
9307 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
9308 This is useful when an output is known not to contain any Qt binaries, and
9309 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
9312 This phase is added after the @code{install} phase.
9316 @defvr {Scheme Variable} r-build-system
9317 This variable is exported by @code{(guix build-system r)}. It
9318 implements the build procedure used by @uref{https://r-project.org, R}
9319 packages, which essentially is little more than running @samp{R CMD
9320 INSTALL --library=/gnu/store/@dots{}} in an environment where
9321 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
9322 run after installation using the R function
9323 @code{tools::testInstalledPackage}.
9326 @defvr {Scheme Variable} rakudo-build-system
9327 This variable is exported by @code{(guix build-system rakudo)}. It
9328 implements the build procedure used by @uref{https://rakudo.org/,
9329 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
9330 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
9331 installs the binaries, library files and the resources, as well as wrap
9332 the files under the @code{bin/} directory. Tests can be skipped by
9333 passing @code{#f} to the @code{tests?} parameter.
9335 Which rakudo package is used can be specified with @code{rakudo}.
9336 Which perl6-tap-harness package used for the tests can be specified with
9337 @code{#:prove6} or removed by passing @code{#f} to the
9338 @code{with-prove6?} parameter.
9339 Which perl6-zef package used for tests and installing can be specified
9340 with @code{#:zef} or removed by passing @code{#f} to the
9341 @code{with-zef?} parameter.
9344 @defvr {Scheme Variable} rebar-build-system
9345 This variable is exported by @code{(guix build-system rebar)}. It
9346 implements a build procedure around @uref{https://rebar3.org,rebar3},
9347 a build system for programs written in the Erlang language.
9349 It adds both @code{rebar3} and the @code{erlang} to the set of inputs.
9350 Different packages can be specified with the @code{#:rebar} and
9351 @code{#:erlang} parameters, respectively.
9353 This build system is based on @code{gnu-build-system}, but with the
9354 following phases changed:
9359 This phase, after unpacking the source like the @code{gnu-build-system}
9360 does, checks for a file @code{contents.tar.gz} at the top-level of the
9361 source. If this file exists, it will be unpacked, too. This eases
9362 handling of package hosted at @uref{https://hex.pm/},
9363 the Erlang and Elixir package repository.
9367 There are no @code{bootstrap} and @code{configure} phase because erlang
9368 packages typically don’t need to be configured.
9371 This phase runs @code{rebar3 compile}
9372 with the flags listed in @code{#:rebar-flags}.
9375 Unless @code{#:tests? #f} is passed,
9376 this phase runs @code{rebar3 eunit},
9377 or some other target specified with @code{#:test-target},
9378 with the flags listed in @code{#:rebar-flags},
9381 This installs the files created in the @i{default} profile, or some
9382 other profile specified with @code{#:install-profile}.
9387 @defvr {Scheme Variable} texlive-build-system
9388 This variable is exported by @code{(guix build-system texlive)}. It is
9389 used to build TeX packages in batch mode with a specified engine. The
9390 build system sets the @env{TEXINPUTS} variable to find all TeX source
9391 files in the inputs.
9393 By default it runs @code{luatex} on all files ending on @code{ins}. A
9394 different engine and format can be specified with the
9395 @code{#:tex-format} argument. Different build targets can be specified
9396 with the @code{#:build-targets} argument, which expects a list of file
9397 names. The build system adds only @code{texlive-bin} and
9398 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
9399 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
9400 and @code{#:texlive-latex-base}, respectively.
9402 The @code{#:tex-directory} parameter tells the build system where to
9403 install the built files under the texmf tree.
9406 @defvr {Scheme Variable} ruby-build-system
9407 This variable is exported by @code{(guix build-system ruby)}. It
9408 implements the RubyGems build procedure used by Ruby packages, which
9409 involves running @code{gem build} followed by @code{gem install}.
9411 The @code{source} field of a package that uses this build system
9412 typically references a gem archive, since this is the format that Ruby
9413 developers use when releasing their software. The build system unpacks
9414 the gem archive, potentially patches the source, runs the test suite,
9415 repackages the gem, and installs it. Additionally, directories and
9416 tarballs may be referenced to allow building unreleased gems from Git or
9417 a traditional source release tarball.
9419 Which Ruby package is used can be specified with the @code{#:ruby}
9420 parameter. A list of additional flags to be passed to the @command{gem}
9421 command can be specified with the @code{#:gem-flags} parameter.
9424 @defvr {Scheme Variable} waf-build-system
9425 This variable is exported by @code{(guix build-system waf)}. It
9426 implements a build procedure around the @code{waf} script. The common
9427 phases---@code{configure}, @code{build}, and @code{install}---are
9428 implemented by passing their names as arguments to the @code{waf}
9431 The @code{waf} script is executed by the Python interpreter. Which
9432 Python package is used to run the script can be specified with the
9433 @code{#:python} parameter.
9436 @defvr {Scheme Variable} scons-build-system
9437 This variable is exported by @code{(guix build-system scons)}. It
9438 implements the build procedure used by the SCons software construction
9439 tool. This build system runs @code{scons} to build the package,
9440 @code{scons test} to run tests, and then @code{scons install} to install
9443 Additional flags to be passed to @code{scons} can be specified with the
9444 @code{#:scons-flags} parameter. The default build and install targets
9445 can be overridden with @code{#:build-targets} and
9446 @code{#:install-targets} respectively. The version of Python used to
9447 run SCons can be specified by selecting the appropriate SCons package
9448 with the @code{#:scons} parameter.
9451 @defvr {Scheme Variable} haskell-build-system
9452 This variable is exported by @code{(guix build-system haskell)}. It
9453 implements the Cabal build procedure used by Haskell packages, which
9454 involves running @code{runhaskell Setup.hs configure
9455 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
9456 Instead of installing the package by running @code{runhaskell Setup.hs
9457 install}, to avoid trying to register libraries in the read-only
9458 compiler store directory, the build system uses @code{runhaskell
9459 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
9460 addition, the build system generates the package documentation by
9461 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
9462 is passed. Optional Haddock parameters can be passed with the help of
9463 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
9464 not found, the build system looks for @code{Setup.lhs} instead.
9466 Which Haskell compiler is used can be specified with the @code{#:haskell}
9467 parameter which defaults to @code{ghc}.
9470 @defvr {Scheme Variable} dub-build-system
9471 This variable is exported by @code{(guix build-system dub)}. It
9472 implements the Dub build procedure used by D packages, which
9473 involves running @code{dub build} and @code{dub run}.
9474 Installation is done by copying the files manually.
9476 Which D compiler is used can be specified with the @code{#:ldc}
9477 parameter which defaults to @code{ldc}.
9480 @anchor{emacs-build-system}
9481 @defvr {Scheme Variable} emacs-build-system
9482 This variable is exported by @code{(guix build-system emacs)}. It
9483 implements an installation procedure similar to the packaging system
9484 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9486 It first creates the @code{@code{package}-autoloads.el} file, then it
9487 byte compiles all Emacs Lisp files. Differently from the Emacs
9488 packaging system, the Info documentation files are moved to the standard
9489 documentation directory and the @file{dir} file is deleted. The Elisp
9490 package files are installed directly under @file{share/emacs/site-lisp}.
9493 @defvr {Scheme Variable} font-build-system
9494 This variable is exported by @code{(guix build-system font)}. It
9495 implements an installation procedure for font packages where upstream
9496 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
9497 need to be copied into place. It copies font files to standard
9498 locations in the output directory.
9501 @defvr {Scheme Variable} meson-build-system
9502 This variable is exported by @code{(guix build-system meson)}. It
9503 implements the build procedure for packages that use
9504 @url{https://mesonbuild.com, Meson} as their build system.
9506 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
9507 of inputs, and they can be changed with the parameters @code{#:meson}
9508 and @code{#:ninja} if needed.
9510 This build system is an extension of @code{gnu-build-system}, but with the
9511 following phases changed to some specific for Meson:
9516 The phase runs @code{meson} with the flags specified in
9517 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
9518 @code{debugoptimized} unless something else is specified in
9519 @code{#:build-type}.
9522 The phase runs @code{ninja} to build the package in parallel by default, but
9523 this can be changed with @code{#:parallel-build?}.
9526 The phase runs @samp{meson test} with a base set of options that cannot
9527 be overridden. This base set of options can be extended via the
9528 @code{#:test-options} argument, for example to select or skip a specific
9532 The phase runs @code{ninja install} and can not be changed.
9535 Apart from that, the build system also adds the following phases:
9540 This phase ensures that all binaries can find the libraries they need.
9541 It searches for required libraries in subdirectories of the package
9542 being built, and adds those to @code{RUNPATH} where needed. It also
9543 removes references to libraries left over from the build phase by
9544 @code{meson}, such as test dependencies, that aren't actually required
9545 for the program to run.
9547 @item glib-or-gtk-wrap
9548 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
9549 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
9551 @item glib-or-gtk-compile-schemas
9552 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
9553 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
9557 @defvr {Scheme Variable} linux-module-build-system
9558 @code{linux-module-build-system} allows building Linux kernel modules.
9560 @cindex build phases
9561 This build system is an extension of @code{gnu-build-system}, but with the
9562 following phases changed:
9567 This phase configures the environment so that the Linux kernel's Makefile
9568 can be used to build the external kernel module.
9571 This phase uses the Linux kernel's Makefile in order to build the external
9575 This phase uses the Linux kernel's Makefile in order to install the external
9579 It is possible and useful to specify the Linux kernel to use for building
9580 the module (in the @code{arguments} form of a package using the
9581 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
9584 @defvr {Scheme Variable} node-build-system
9585 This variable is exported by @code{(guix build-system node)}. It
9586 implements the build procedure used by @uref{https://nodejs.org,
9587 Node.js}, which implements an approximation of the @code{npm install}
9588 command, followed by an @code{npm test} command.
9590 Which Node.js package is used to interpret the @code{npm} commands can
9591 be specified with the @code{#:node} parameter which defaults to
9595 Lastly, for packages that do not need anything as sophisticated, a
9596 ``trivial'' build system is provided. It is trivial in the sense that
9597 it provides basically no support: it does not pull any implicit inputs,
9598 and does not have a notion of build phases.
9600 @defvr {Scheme Variable} trivial-build-system
9601 This variable is exported by @code{(guix build-system trivial)}.
9603 This build system requires a @code{#:builder} argument. This argument
9604 must be a Scheme expression that builds the package output(s)---as
9605 with @code{build-expression->derivation} (@pxref{Derivations,
9606 @code{build-expression->derivation}}).
9609 @defvr {Scheme Variable} channel-build-system
9610 This variable is exported by @code{(guix build-system channel)}.
9612 This build system is meant primarily for internal use. A package using
9613 this build system must have a channel specification as its @code{source}
9614 field (@pxref{Channels}); alternatively, its source can be a directory
9615 name, in which case an additional @code{#:commit} argument must be
9616 supplied to specify the commit being built (a hexadecimal string).
9618 The resulting package is a Guix instance of the given channel, similar
9619 to how @command{guix time-machine} would build it.
9623 @section Build Phases
9625 @cindex build phases, for packages
9626 Almost all package build systems implement a notion @dfn{build phases}:
9627 a sequence of actions that the build system executes, when you build the
9628 package, leading to the installed byproducts in the store. A notable
9629 exception is the ``bare-bones'' @code{trivial-build-system}
9630 (@pxref{Build Systems}).
9632 As discussed in the previous section, those build systems provide a
9633 standard list of phases. For @code{gnu-build-system}, the main build
9634 phases are the following:
9638 Define search path environment variables for all the input packages,
9639 including @env{PATH} (@pxref{Search Paths}).
9642 Unpack the source tarball, and change the current directory to the
9643 extracted source tree. If the source is actually a directory, copy it
9644 to the build tree, and enter that directory.
9646 @item patch-source-shebangs
9647 Patch shebangs encountered in source files so they refer to the right
9648 store file names. For instance, this changes @code{#!/bin/sh} to
9649 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
9652 Run the @file{configure} script with a number of default options, such
9653 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
9654 by the @code{#:configure-flags} argument.
9657 Run @code{make} with the list of flags specified with
9658 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
9659 (the default), build with @code{make -j}.
9662 Run @code{make check}, or some other target specified with
9663 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
9664 @code{#:parallel-tests?} argument is true (the default), run @code{make
9668 Run @code{make install} with the flags listed in @code{#:make-flags}.
9670 @item patch-shebangs
9671 Patch shebangs on the installed executable files.
9674 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
9675 is false), copying them to the @code{debug} output when available
9676 (@pxref{Installing Debugging Files}).
9678 @cindex RUNPATH, validation
9679 @anchor{phase-validate-runpath}
9680 @item validate-runpath
9681 Validate the @code{RUNPATH} of ELF binaries, unless
9682 @code{#:validate-runpath?} is false (@pxref{Build Systems}).
9684 This validation step consists in making sure that all the shared
9685 libraries needed by an ELF binary, which are listed as @code{DT_NEEDED}
9686 entries in its @code{PT_DYNAMIC} segment, appear in the
9687 @code{DT_RUNPATH} entry of that binary. In other words, it ensures that
9688 running or using those binaries will not result in a ``file not found''
9689 error at run time. @xref{Options, @option{-rpath},, ld, The GNU
9690 Linker}, for more information on @code{RUNPATH}.
9694 Other build systems have similar phases, with some variations. For
9695 example, @code{cmake-build-system} has same-named phases but its
9696 @code{configure} phases runs @code{cmake} instead of @code{./configure}.
9697 Others, such as @code{python-build-system}, have a wholly different list
9698 of standard phases. All this code runs on the @dfn{build side}: it is
9699 evaluated when you actually build the package, in a dedicated build
9700 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
9702 Build phases are represented as association lists or ``alists''
9703 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
9704 each key is a symbol for the name of the phase and the associated value
9705 is a procedure that accepts an arbitrary number of arguments. By
9706 convention, those procedures receive information about the build in the
9707 form of @dfn{keyword parameters}, which they can use or ignore.
9709 @vindex %standard-phases
9710 For example, here is how @code{(guix build gnu-build-system)} defines
9711 @code{%standard-phases}, the variable holding its alist of build
9712 phases@footnote{We present a simplified view of those build phases, but
9713 do take a look at @code{(guix build gnu-build-system)} to see all the
9717 ;; The build phases of 'gnu-build-system'.
9719 (define* (unpack #:key source #:allow-other-keys)
9720 ;; Extract the source tarball.
9721 (invoke "tar" "xvf" source))
9723 (define* (configure #:key outputs #:allow-other-keys)
9724 ;; Run the 'configure' script. Install to output "out".
9725 (let ((out (assoc-ref outputs "out")))
9726 (invoke "./configure"
9727 (string-append "--prefix=" out))))
9729 (define* (build #:allow-other-keys)
9733 (define* (check #:key (test-target "check") (tests? #true)
9735 ;; Run the test suite.
9737 (invoke "make" test-target)
9738 (display "test suite not run\n")))
9740 (define* (install #:allow-other-keys)
9741 ;; Install files to the prefix 'configure' specified.
9742 (invoke "make" "install"))
9744 (define %standard-phases
9745 ;; The list of standard phases (quite a few are omitted
9746 ;; for brevity). Each element is a symbol/procedure pair.
9747 (list (cons 'unpack unpack)
9748 (cons 'configure configure)
9751 (cons 'install install)))
9754 This shows how @code{%standard-phases} is defined as a list of
9755 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
9756 Manual}). The first pair associates the @code{unpack} procedure with
9757 the @code{unpack} symbol---a name; the second pair defines the
9758 @code{configure} phase similarly, and so on. When building a package
9759 that uses @code{gnu-build-system} with its default list of phases, those
9760 phases are executed sequentially. You can see the name of each phase
9761 started and completed in the build log of packages that you build.
9763 Let's now look at the procedures themselves. Each one is defined with
9764 @code{define*}: @code{#:key} lists keyword parameters the procedure
9765 accepts, possibly with a default value, and @code{#:allow-other-keys}
9766 specifies that other keyword parameters are ignored (@pxref{Optional
9767 Arguments,,, guile, GNU Guile Reference Manual}).
9769 The @code{unpack} procedure honors the @code{source} parameter, which
9770 the build system uses to pass the file name of the source tarball (or
9771 version control checkout), and it ignores other parameters. The
9772 @code{configure} phase only cares about the @code{outputs} parameter, an
9773 alist mapping package output names to their store file name
9774 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
9775 for @code{out}, the default output, and passes it to
9776 @command{./configure} as the installation prefix, meaning that
9777 @command{make install} will eventually copy all the files in that
9778 directory (@pxref{Configuration, configuration and makefile
9779 conventions,, standards, GNU Coding Standards}). @code{build} and
9780 @code{install} ignore all their arguments. @code{check} honors the
9781 @code{test-target} argument, which specifies the name of the Makefile
9782 target to run tests; it prints a message and skips tests when
9783 @code{tests?} is false.
9785 @cindex build phases, customizing
9786 The list of phases used for a particular package can be changed with the
9787 @code{#:phases} parameter of the build system. Changing the set of
9788 build phases boils down to building a new alist of phases based on the
9789 @code{%standard-phases} alist described above. This can be done with
9790 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
9791 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
9792 more convenient to do so with @code{modify-phases} (@pxref{Build
9793 Utilities, @code{modify-phases}}).
9795 Here is an example of a package definition that removes the
9796 @code{configure} phase of @code{%standard-phases} and inserts a new
9797 phase before the @code{build} phase, called
9798 @code{set-prefix-in-makefile}:
9801 (define-public example
9804 ;; other fields omitted
9805 (build-system gnu-build-system)
9807 '(#:phases (modify-phases %standard-phases
9809 (add-before 'build 'set-prefix-in-makefile
9810 (lambda* (#:key outputs #:allow-other-keys)
9811 ;; Modify the makefile so that its
9812 ;; 'PREFIX' variable points to "out".
9813 (let ((out (assoc-ref outputs "out")))
9814 (substitute* "Makefile"
9816 (string-append "PREFIX = "
9820 The new phase that is inserted is written as an anonymous procedure,
9821 introduced with @code{lambda*}; it honors the @code{outputs} parameter
9822 we have seen before. @xref{Build Utilities}, for more about the helpers
9823 used by this phase, and for more examples of @code{modify-phases}.
9825 @cindex code staging
9826 @cindex staging, of code
9827 Keep in mind that build phases are code evaluated at the time the
9828 package is actually built. This explains why the whole
9829 @code{modify-phases} expression above is quoted (it comes after the
9830 @code{'} or apostrophe): it is @dfn{staged} for later execution.
9831 @xref{G-Expressions}, for an explanation of code staging and the
9832 @dfn{code strata} involved.
9834 @node Build Utilities
9835 @section Build Utilities
9837 As soon as you start writing non-trivial package definitions
9838 (@pxref{Defining Packages}) or other build actions
9839 (@pxref{G-Expressions}), you will likely start looking for helpers for
9840 ``shell-like'' actions---creating directories, copying and deleting
9841 files recursively, manipulating build phases, and so on. The
9842 @code{(guix build utils)} module provides such utility procedures.
9844 Most build systems load @code{(guix build utils)} (@pxref{Build
9845 Systems}). Thus, when writing custom build phases for your package
9846 definitions, you can usually assume those procedures are in scope.
9848 When writing G-expressions, you can import @code{(guix build utils)} on
9849 the ``build side'' using @code{with-imported-modules} and then put it in
9850 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
9851 guile, GNU Guile Reference Manual}):
9854 (with-imported-modules '((guix build utils)) ;import it
9855 (computed-file "empty-tree"
9858 (use-modules (guix build utils))
9860 ;; Happily use its 'mkdir-p' procedure.
9861 (mkdir-p (string-append #$output "/a/b/c")))))
9864 The remainder of this section is the reference for most of the utility
9865 procedures provided by @code{(guix build utils)}.
9867 @c TODO Document what's missing.
9869 @subsection Dealing with Store File Names
9871 This section documents procedures that deal with store file names.
9873 @deffn {Scheme Procedure} %store-directory
9874 Return the directory name of the store.
9877 @deffn {Scheme Procedure} store-file-name? @var{file}
9878 Return true if @var{file} is in the store.
9881 @deffn {Scheme Procedure} strip-store-file-name @var{file}
9882 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
9883 The result is typically a @code{"@var{package}-@var{version}"} string.
9886 @deffn {Scheme Procedure} package-name->name+version @var{name}
9887 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
9888 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
9889 unavailable, @var{name} and @code{#f} are returned. The first hyphen
9890 followed by a digit is considered to introduce the version part.
9893 @subsection File Types
9895 The procedures below deal with files and file types.
9897 @deffn {Scheme Procedure} directory-exists? @var{dir}
9898 Return @code{#t} if @var{dir} exists and is a directory.
9901 @deffn {Scheme Procedure} executable-file? @var{file}
9902 Return @code{#t} if @var{file} exists and is executable.
9905 @deffn {Scheme Procedure} symbolic-link? @var{file}
9906 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
9909 @deffn {Scheme Procedure} elf-file? @var{file}
9910 @deffnx {Scheme Procedure} ar-file? @var{file}
9911 @deffnx {Scheme Procedure} gzip-file? @var{file}
9912 Return @code{#t} if @var{file} is, respectively, an ELF file, an
9913 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
9916 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
9917 If @var{file} is a gzip file, reset its embedded timestamp (as with
9918 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
9919 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
9922 @subsection File Manipulation
9924 The following procedures and macros help create, modify, and delete
9925 files. They provide functionality comparable to common shell utilities
9926 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
9927 @command{sed}. They complement Guile's extensive, but low-level, file
9928 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
9930 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
9931 Run @var{body} with @var{directory} as the process's current directory.
9933 Essentially, this macro changes the current directory to @var{directory}
9934 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
9935 guile, GNU Guile Reference Manual}). It changes back to the initial
9936 directory when the dynamic extent of @var{body} is left, be it @i{via}
9937 normal procedure return or @i{via} a non-local exit such as an
9941 @deffn {Scheme Procedure} mkdir-p @var{dir}
9942 Create directory @var{dir} and all its ancestors.
9945 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
9946 Create @var{directory} if it does not exist and copy @var{file} in there
9947 under the same name.
9950 @deffn {Scheme Procedure} make-file-writable @var{file}
9951 Make @var{file} writable for its owner.
9954 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
9955 [#:log (current-output-port)] [#:follow-symlinks? #f] @
9956 [#:copy-file copy-file] [#:keep-mtime? #f] [#:keep-permissions? #t]
9957 Copy @var{source} directory to @var{destination}. Follow symlinks if
9958 @var{follow-symlinks?} is true; otherwise, just preserve them. Call
9959 @var{copy-file} to copy regular files. When @var{keep-mtime?} is true,
9960 keep the modification time of the files in @var{source} on those of
9961 @var{destination}. When @var{keep-permissions?} is true, preserve file
9962 permissions. Write verbose output to the @var{log} port.
9965 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
9966 [#:follow-mounts? #f]
9967 Delete @var{dir} recursively, like @command{rm -rf}, without following
9968 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
9969 is true. Report but ignore errors.
9972 @deffn {Scheme Syntax} substitute* @var{file} @
9973 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
9974 Substitute @var{regexp} in @var{file} by the string returned by
9975 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
9976 the corresponding positional regexp sub-expression. For example:
9982 (("foo([a-z]+)bar(.*)$" all letters end)
9983 (string-append "baz" letters end)))
9986 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
9987 by @code{good morning}. Anytime a line of @var{file} matches the second
9988 regexp, @code{all} is bound to the complete match, @code{letters} is bound
9989 to the first sub-expression, and @code{end} is bound to the last one.
9991 When one of the @var{match-var} is @code{_}, no variable is bound to the
9992 corresponding match substring.
9994 Alternatively, @var{file} may be a list of file names, in which case
9995 they are all subject to the substitutions.
9997 Be careful about using @code{$} to match the end of a line; by itself it
9998 won't match the terminating newline of a line.
10001 @subsection File Search
10003 @cindex file, searching
10004 This section documents procedures to search and filter files.
10006 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
10007 Return a predicate that returns true when passed a file name whose base
10008 name matches @var{regexp}.
10011 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
10012 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
10013 Return the lexicographically sorted list of files under @var{dir} for
10014 which @var{pred} returns true. @var{pred} is passed two arguments: the
10015 absolute file name, and its stat buffer; the default predicate always
10016 returns true. @var{pred} can also be a regular expression, in which
10017 case it is equivalent to @code{(file-name-predicate @var{pred})}.
10018 @var{stat} is used to obtain file information; using @code{lstat} means
10019 that symlinks are not followed. If @var{directories?} is true, then
10020 directories will also be included. If @var{fail-on-error?} is true,
10021 raise an exception upon error.
10024 Here are a few examples where we assume that the current directory is
10025 the root of the Guix source tree:
10028 ;; List all the regular files in the current directory.
10030 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
10032 ;; List all the .scm files under gnu/services.
10033 (find-files "gnu/services" "\\.scm$")
10034 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
10036 ;; List ar files in the current directory.
10037 (find-files "." (lambda (file stat) (ar-file? file)))
10038 @result{} ("./libformat.a" "./libstore.a" @dots{})
10041 @deffn {Scheme Procedure} which @var{program}
10042 Return the complete file name for @var{program} as found in
10043 @code{$PATH}, or @code{#f} if @var{program} could not be found.
10046 @deffn {Scheme Procedure} search-input-file @var{inputs} @var{name}
10047 @deffnx {Scheme Procedure} search-input-directory @var{inputs} @var{name}
10048 Return the complete file name for @var{name} as found in @var{inputs};
10049 @code{search-input-file} searches for a regular file and
10050 @code{search-input-directory} searches for a directory. If @var{name}
10051 could not be found, an exception is raised.
10053 Here, @var{inputs} must be an association list like @code{inputs} and
10054 @code{native-inputs} as available to build phases (@pxref{Build
10058 Here is a (simplified) example of how @code{search-input-file} is used
10059 in a build phase of the @code{wireguard-tools} package:
10062 (add-after 'install 'wrap-wg-quick
10063 (lambda* (#:key inputs outputs #:allow-other-keys)
10064 (let ((coreutils (string-append (assoc-ref inputs "coreutils")
10066 (wrap-program (search-input-file outputs "bin/wg-quick")
10067 #:sh (search-input-file inputs "bin/bash")
10068 `("PATH" ":" prefix ,(list coreutils))))))
10071 @subsection Program Invocation
10073 @cindex program invocation, from Scheme
10074 @cindex invoking programs, from Scheme
10075 You'll find handy procedures to spawn processes in this module,
10076 essentially convenient wrappers around Guile's @code{system*}
10077 (@pxref{Processes, @code{system*},, guile, GNU Guile Reference Manual}).
10079 @deffn {Scheme Procedure} invoke @var{program} @var{args}@dots{}
10080 Invoke @var{program} with the given @var{args}. Raise an
10081 @code{&invoke-error} exception if the exit code is non-zero; otherwise
10084 The advantage compared to @code{system*} is that you do not need to
10085 check the return value. This reduces boilerplate in shell-script-like
10086 snippets for instance in package build phases.
10089 @deffn {Scheme Procedure} invoke-error? @var{c}
10090 Return true if @var{c} is an @code{&invoke-error} condition.
10093 @deffn {Scheme Procedure} invoke-error-program @var{c}
10094 @deffnx {Scheme Procedure} invoke-error-arguments @var{c}
10095 @deffnx {Scheme Procedure} invoke-error-exit-status @var{c}
10096 @deffnx {Scheme Procedure} invoke-error-term-signal @var{c}
10097 @deffnx {Scheme Procedure} invoke-error-stop-signal @var{c}
10098 Access specific fields of @var{c}, an @code{&invoke-error} condition.
10101 @deffn {Scheme Procedure} report-invoke-error @var{c} [@var{port}]
10102 Report to @var{port} (by default the current error port) about @var{c},
10103 an @code{&invoke-error} condition, in a human-friendly way.
10105 Typical usage would look like this:
10108 (use-modules (srfi srfi-34) ;for 'guard'
10109 (guix build utils))
10111 (guard (c ((invoke-error? c)
10112 (report-invoke-error c)))
10113 (invoke "date" "--imaginary-option"))
10115 @print{} command "date" "--imaginary-option" failed with status 1
10119 @deffn {Scheme Procedure} invoke/quiet @var{program} @var{args}@dots{}
10120 Invoke @var{program} with @var{args} and capture @var{program}'s
10121 standard output and standard error. If @var{program} succeeds, print
10122 nothing and return the unspecified value; otherwise, raise a
10123 @code{&message} error condition that includes the status code and the
10124 output of @var{program}.
10129 (use-modules (srfi srfi-34) ;for 'guard'
10130 (srfi srfi-35) ;for 'message-condition?'
10131 (guix build utils))
10133 (guard (c ((message-condition? c)
10134 (display (condition-message c))))
10135 (invoke/quiet "date") ;all is fine
10136 (invoke/quiet "date" "--imaginary-option"))
10138 @print{} 'date --imaginary-option' exited with status 1; output follows:
10140 date: unrecognized option '--imaginary-option'
10141 Try 'date --help' for more information.
10145 @subsection Build Phases
10147 @cindex build phases
10148 The @code{(guix build utils)} also contains tools to manipulate build
10149 phases as used by build systems (@pxref{Build Systems}). Build phases
10150 are represented as association lists or ``alists'' (@pxref{Association
10151 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
10152 naming the phase and the associated value is a procedure (@pxref{Build
10155 Guile core and the @code{(srfi srfi-1)} module both provide tools to
10156 manipulate alists. The @code{(guix build utils)} module complements
10157 those with tools written with build phases in mind.
10159 @cindex build phases, modifying
10160 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
10161 Modify @var{phases} sequentially as per each @var{clause}, which may
10162 have one of the following forms:
10165 (delete @var{old-phase-name})
10166 (replace @var{old-phase-name} @var{new-phase})
10167 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
10168 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
10171 Where every @var{phase-name} above is an expression evaluating to a
10172 symbol, and @var{new-phase} an expression evaluating to a procedure.
10175 The example below is taken from the definition of the @code{grep}
10176 package. It adds a phase to run after the @code{install} phase, called
10177 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
10178 is for anonymous procedures) that takes a @code{#:outputs} keyword
10179 argument and ignores extra keyword arguments (@pxref{Optional
10180 Arguments,,, guile, GNU Guile Reference Manual}, for more on
10181 @code{lambda*} and optional and keyword arguments.) The phase uses
10182 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
10183 scripts so that they refer to @code{grep} by its absolute file name:
10186 (modify-phases %standard-phases
10187 (add-after 'install 'fix-egrep-and-fgrep
10188 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
10189 ;; absolute file name instead of searching for it in $PATH.
10190 (lambda* (#:key outputs #:allow-other-keys)
10191 (let* ((out (assoc-ref outputs "out"))
10192 (bin (string-append out "/bin")))
10193 (substitute* (list (string-append bin "/egrep")
10194 (string-append bin "/fgrep"))
10196 (string-append "exec " bin "/grep")))))))
10199 In the example below, phases are modified in two ways: the standard
10200 @code{configure} phase is deleted, presumably because the package does
10201 not have a @file{configure} script or anything similar, and the default
10202 @code{install} phase is replaced by one that manually copies the
10203 executable files to be installed:
10206 (modify-phases %standard-phases
10207 (delete 'configure) ;no 'configure' script
10209 (lambda* (#:key outputs #:allow-other-keys)
10210 ;; The package's Makefile doesn't provide an "install"
10211 ;; rule so do it by ourselves.
10212 (let ((bin (string-append (assoc-ref outputs "out")
10214 (install-file "footswitch" bin)
10215 (install-file "scythe" bin)))))
10218 @c TODO: Add more examples.
10220 @subsection Wrappers
10222 @cindex program wrappers
10223 @cindex wrapping programs
10224 It is not unusual for a command to require certain environment variables
10225 to be set for proper functioning, typically search paths (@pxref{Search
10226 Paths}). Failing to do that, the command might fail to find files or
10227 other commands it relies on, or it might pick the ``wrong''
10228 ones---depending on the environment in which it runs. Examples include:
10232 a shell script that assumes all the commands it uses are in @env{PATH};
10235 a Guile program that assumes all its modules are in @env{GUILE_LOAD_PATH}
10236 and @env{GUILE_LOAD_COMPILED_PATH};
10239 a Qt application that expects to find certain plugins in
10240 @env{QT_PLUGIN_PATH}.
10243 For a package writer, the goal is to make sure commands always work the
10244 same rather than depend on some external settings. One way to achieve
10245 that is to @dfn{wrap} commands in a thin script that sets those
10246 environment variables, thereby ensuring that those run-time dependencies
10247 are always found. The wrapper would be used to set @env{PATH},
10248 @env{GUILE_LOAD_PATH}, or @env{QT_PLUGIN_PATH} in the examples above.
10250 To ease that task, the @code{(guix build utils)} module provides a
10251 couple of helpers to wrap commands.
10253 @deffn {Scheme Procedure} wrap-program @var{program} @
10254 [#:sh @var{sh}] [#:rest @var{variables}]
10255 Make a wrapper for @var{program}. @var{variables} should look like this:
10258 '(@var{variable} @var{delimiter} @var{position} @var{list-of-directories})
10261 where @var{delimiter} is optional. @code{:} will be used if
10262 @var{delimiter} is not given.
10264 For example, this call:
10267 (wrap-program "foo"
10268 '("PATH" ":" = ("/gnu/.../bar/bin"))
10269 '("CERT_PATH" suffix ("/gnu/.../baz/certs"
10273 will copy @file{foo} to @file{.foo-real} and create the file @file{foo}
10274 with the following contents:
10277 #!location/of/bin/bash
10278 export PATH="/gnu/.../bar/bin"
10279 export CERT_PATH="$CERT_PATH$@{CERT_PATH:+:@}/gnu/.../baz/certs:/qux/certs"
10280 exec -a $0 location/of/.foo-real "$@@"
10283 If @var{program} has previously been wrapped by @code{wrap-program}, the
10284 wrapper is extended with definitions for @var{variables}. If it is not,
10285 @var{sh} will be used as the interpreter.
10288 @deffn {Scheme Procedure} wrap-script @var{program} @
10289 [#:guile @var{guile}] [#:rest @var{variables}]
10290 Wrap the script @var{program} such that @var{variables} are set first.
10291 The format of @var{variables} is the same as in the @code{wrap-program}
10292 procedure. This procedure differs from @code{wrap-program} in that it
10293 does not create a separate shell script. Instead, @var{program} is
10294 modified directly by prepending a Guile script, which is interpreted as
10295 a comment in the script's language.
10297 Special encoding comments as supported by Python are recreated on the
10300 Note that this procedure can only be used once per file as Guile scripts are
10305 @section Search Paths
10307 @cindex search path
10308 Many programs and libraries look for input data in a @dfn{search path},
10309 a list of directories: shells like Bash look for executables in the
10310 command search path, a C compiler looks for @file{.h} files in its
10311 header search path, the Python interpreter looks for @file{.py}
10312 files in its search path, the spell checker has a search path for
10313 dictionaries, and so on.
10315 Search paths can usually be defined or overridden @i{via} environment
10316 variables (@pxref{Environment Variables,,, libc, The GNU C Library
10317 Reference Manual}). For example, the search paths mentioned above can
10318 be changed by defining the @env{PATH}, @env{C_INCLUDE_PATH},
10319 @env{PYTHONPATH} (or @env{GUIX_PYTHONPATH}), and @env{DICPATH}
10320 environment variables---you know, all these something-PATH variables
10321 that you need to get right or things ``won't be found''.
10323 You may have noticed from the command line that Guix ``knows'' which
10324 search path environment variables should be defined, and how. When you
10325 install packages in your default profile, the file
10326 @file{~/.guix-profile/etc/profile} is created, which you can ``source''
10327 from the shell to set those variables. Likewise, if you ask
10328 @command{guix shell} to create an environment containing Python and
10329 NumPy, a Python library, and if you pass it the @option{--search-paths}
10330 option, it will tell you about @env{PATH} and @env{GUIX_PYTHONPATH}
10331 (@pxref{Invoking guix shell}):
10334 $ guix shell python python-numpy --pure --search-paths
10335 export PATH="/gnu/store/@dots{}-profile/bin"
10336 export GUIX_PYTHONPATH="/gnu/store/@dots{}-profile/lib/python3.9/site-packages"
10339 When you omit @option{--search-paths}, it defines these environment
10340 variables right away, such that Python can readily find NumPy:
10343 $ guix shell python python-numpy -- python3
10344 Python 3.9.6 (default, Jan 1 1970, 00:00:01)
10345 [GCC 10.3.0] on linux
10346 Type "help", "copyright", "credits" or "license" for more information.
10348 >>> numpy.version.version
10352 For this to work, the definition of the @code{python} package
10353 @emph{declares} the search path it cares about and its associated
10354 environment variable, @env{GUIX_PYTHONPATH}. It looks like this:
10360 ;; some fields omitted...
10361 (native-search-paths
10362 (list (search-path-specification
10363 (variable "GUIX_PYTHONPATH")
10364 (files (list "lib/python/3.9/site-packages"))))))
10367 What this @code{native-search-paths} field says is that, when the
10368 @code{python} package is used, the @env{GUIX_PYTHONPATH} environment
10369 variable must be defined to include all the
10370 @file{lib/python/3.9/site-packages} sub-directories encountered in its
10371 environment. (The @code{native-} bit means that, if we are in a
10372 cross-compilation environment, only native inputs may be added to the
10373 search path; @pxref{package Reference, @code{search-paths}}.)
10374 In the NumPy example above, the profile where
10375 @code{python} appears contains exactly one such sub-directory, and
10376 @env{GUIX_PYTHONPATH} is set to that. When there are several
10377 @file{lib/python/3.9/site-packages}---this is the case in package build
10378 environments---they are all added to @env{GUIX_PYTHONPATH}, separated by
10382 Notice that @env{GUIX_PYTHONPATH} is specified as part of the definition
10383 of the @code{python} package, and @emph{not} as part of that of
10384 @code{python-numpy}. This is because this environment variable
10385 ``belongs'' to Python, not NumPy: Python actually reads the value of
10386 that variable and honors it.
10388 Corollary: if you create a profile that does not contain @code{python},
10389 @code{GUIX_PYTHONPATH} will @emph{not} be defined, even if it contains
10390 packages that provide @file{.py} files:
10393 $ guix shell python-numpy --search-paths --pure
10394 export PATH="/gnu/store/@dots{}-profile/bin"
10397 This makes a lot of sense if we look at this profile in isolation: no
10398 software in this profile would read @env{GUIX_PYTHONPATH}.
10401 Of course, there are many variations on that theme: some packages honor
10402 more than one search path, some use separators other than colon, some
10403 accumulate several directories in their search path, and so on. A more
10404 complex example is the search path of libxml2: the value of the
10405 @env{XML_CATALOG_FILES} environment variable is space-separated, it must
10406 contain a list of @file{catalog.xml} files (not directories), which are
10407 to be found in @file{xml} sub-directories---nothing less. The search
10408 path specification looks like this:
10413 ;; some fields omitted
10414 (native-search-paths
10415 (list (search-path-specification
10416 (variable "XML_CATALOG_FILES")
10419 (file-pattern "^catalog\\.xml$")
10420 (file-type 'regular)))))
10423 Worry not, search path specifications are usually not this tricky.
10425 The @code{(guix search-paths)} module defines the data type of search
10426 path specifications and a number of helper procedures. Below is the
10427 reference of search path specifications.
10429 @deftp {Data Type} search-path-specification
10430 The data type for search path specifications.
10433 @item @code{variable}
10434 The name of the environment variable for this search path (a string).
10437 The list of sub-directories (strings) that should be added to the search
10440 @item @code{separator} (default: @code{":"})
10441 The string used to separate search path components.
10443 As a special case, a @code{separator} value of @code{#f} specifies a
10444 ``single-component search path''---in other words, a search path that
10445 cannot contain more than one element. This is useful in some cases,
10446 such as the @code{SSL_CERT_DIR} variable (honored by OpenSSL, cURL, and
10447 a few other packages) or the @code{ASPELL_DICT_DIR} variable (honored by
10448 the GNU Aspell spell checker), both of which must point to a single
10451 @item @code{file-type} (default: @code{'directory})
10452 The type of file being matched---@code{'directory} or @code{'regular},
10453 though it can be any symbol returned by @code{stat:type} (@pxref{File
10454 System, @code{stat},, guile, GNU Guile Reference Manual}).
10456 In the libxml2 example above, we would match regular files; in the
10457 Python example, we would match directories.
10459 @item @code{file-pattern} (default: @code{#f})
10460 This must be either @code{#f} or a regular expression specifying
10461 files to be matched @emph{within} the sub-directories specified by the
10462 @code{files} field.
10464 Again, the libxml2 example shows a situation where this is needed.
10468 Some search paths are not tied by a single package but to many packages.
10469 To reduce duplications, some of them are pre-defined in @code{(guix
10472 @defvr {Scheme Variable} $SSL_CERT_DIR
10473 @defvrx {Scheme Variable} $SSL_CERT_FILE
10474 These two search paths indicate where X.509 certificates can be found
10475 (@pxref{X.509 Certificates}).
10478 These pre-defined search paths can be used as in the following example:
10483 ;; some fields omitted ...
10484 (native-search-paths (list $SSL_CERT_DIR $SSL_CERT_FILE)))
10487 How do you turn search path specifications on one hand and a bunch of
10488 directories on the other hand in a set of environment variable
10489 definitions? That's the job of @code{evaluate-search-paths}.
10491 @deffn {Scheme Procedure} evaluate-search-paths @var{search-paths} @
10492 @var{directories} [@var{getenv}]
10493 Evaluate @var{search-paths}, a list of search-path specifications, for
10494 @var{directories}, a list of directory names, and return a list of
10495 specification/value pairs. Use @var{getenv} to determine the current
10496 settings and report only settings not already effective.
10499 The @code{(guix profiles)} provides a higher-level helper procedure,
10500 @code{load-profile}, that sets the environment variables of a profile.
10506 @cindex store items
10507 @cindex store paths
10509 Conceptually, the @dfn{store} is the place where derivations that have
10510 been built successfully are stored---by default, @file{/gnu/store}.
10511 Sub-directories in the store are referred to as @dfn{store items} or
10512 sometimes @dfn{store paths}. The store has an associated database that
10513 contains information such as the store paths referred to by each store
10514 path, and the list of @emph{valid} store items---results of successful
10515 builds. This database resides in @file{@var{localstatedir}/guix/db},
10516 where @var{localstatedir} is the state directory specified @i{via}
10517 @option{--localstatedir} at configure time, usually @file{/var}.
10519 The store is @emph{always} accessed by the daemon on behalf of its clients
10520 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
10521 connect to the daemon over a Unix-domain socket, send requests to it,
10522 and read the result---these are remote procedure calls, or RPCs.
10525 Users must @emph{never} modify files under @file{/gnu/store} directly.
10526 This would lead to inconsistencies and break the immutability
10527 assumptions of Guix's functional model (@pxref{Introduction}).
10529 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
10530 how to check the integrity of the store and attempt recovery from
10531 accidental modifications.
10534 The @code{(guix store)} module provides procedures to connect to the
10535 daemon, and to perform RPCs. These are described below. By default,
10536 @code{open-connection}, and thus all the @command{guix} commands,
10537 connect to the local daemon or to the URI specified by the
10538 @env{GUIX_DAEMON_SOCKET} environment variable.
10540 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
10541 When set, the value of this variable should be a file name or a URI
10542 designating the daemon endpoint. When it is a file name, it denotes a
10543 Unix-domain socket to connect to. In addition to file names, the
10544 supported URI schemes are:
10549 These are for Unix-domain sockets.
10550 @code{file:///var/guix/daemon-socket/socket} is equivalent to
10551 @file{/var/guix/daemon-socket/socket}.
10554 @cindex daemon, remote access
10555 @cindex remote access to the daemon
10556 @cindex daemon, cluster setup
10557 @cindex clusters, daemon setup
10558 These URIs denote connections over TCP/IP, without encryption nor
10559 authentication of the remote host. The URI must specify the host name
10560 and optionally a port number (by default port 44146 is used):
10563 guix://master.guix.example.org:1234
10566 This setup is suitable on local networks, such as clusters, where only
10567 trusted nodes may connect to the build daemon at
10568 @code{master.guix.example.org}.
10570 The @option{--listen} option of @command{guix-daemon} can be used to
10571 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
10572 @option{--listen}}).
10575 @cindex SSH access to build daemons
10576 These URIs allow you to connect to a remote daemon over SSH@. This
10577 feature requires Guile-SSH (@pxref{Requirements}) and a working
10578 @command{guile} binary in @env{PATH} on the destination machine. It
10579 supports public key and GSSAPI authentication. A typical URL might look
10583 ssh://charlie@@guix.example.org:22
10586 As for @command{guix copy}, the usual OpenSSH client configuration files
10587 are honored (@pxref{Invoking guix copy}).
10590 Additional URI schemes may be supported in the future.
10592 @c XXX: Remove this note when the protocol incurs fewer round trips
10593 @c and when (guix derivations) no longer relies on file system access.
10595 The ability to connect to remote build daemons is considered
10596 experimental as of @value{VERSION}. Please get in touch with us to
10597 share any problems or suggestions you may have (@pxref{Contributing}).
10601 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
10602 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
10603 @var{reserve-space?} is true, instruct it to reserve a little bit of
10604 extra space on the file system so that the garbage collector can still
10605 operate should the disk become full. Return a server object.
10607 @var{file} defaults to @code{%default-socket-path}, which is the normal
10608 location given the options that were passed to @command{configure}.
10611 @deffn {Scheme Procedure} close-connection @var{server}
10612 Close the connection to @var{server}.
10615 @defvr {Scheme Variable} current-build-output-port
10616 This variable is bound to a SRFI-39 parameter, which refers to the port
10617 where build and error logs sent by the daemon should be written.
10620 Procedures that make RPCs all take a server object as their first
10623 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
10624 @cindex invalid store items
10625 Return @code{#t} when @var{path} designates a valid store item and
10626 @code{#f} otherwise (an invalid item may exist on disk but still be
10627 invalid, for instance because it is the result of an aborted or failed
10630 A @code{&store-protocol-error} condition is raised if @var{path} is not
10631 prefixed by the store directory (@file{/gnu/store}).
10634 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
10635 Add @var{text} under file @var{name} in the store, and return its store
10636 path. @var{references} is the list of store paths referred to by the
10637 resulting store path.
10640 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
10642 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
10643 file names, or derivation/output pairs, using the specified
10644 @var{mode}---@code{(build-mode normal)} by default.
10647 Note that the @code{(guix monads)} module provides a monad as well as
10648 monadic versions of the above procedures, with the goal of making it
10649 more convenient to work with code that accesses the store (@pxref{The
10653 @i{This section is currently incomplete.}
10656 @section Derivations
10658 @cindex derivations
10659 Low-level build actions and the environment in which they are performed
10660 are represented by @dfn{derivations}. A derivation contains the
10661 following pieces of information:
10665 The outputs of the derivation---derivations produce at least one file or
10666 directory in the store, but may produce more.
10669 @cindex build-time dependencies
10670 @cindex dependencies, build-time
10671 The inputs of the derivations---i.e., its build-time dependencies---which may
10672 be other derivations or plain files in the store (patches, build scripts,
10676 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
10679 The file name of a build script in the store, along with the arguments
10683 A list of environment variables to be defined.
10687 @cindex derivation path
10688 Derivations allow clients of the daemon to communicate build actions to
10689 the store. They exist in two forms: as an in-memory representation,
10690 both on the client- and daemon-side, and as files in the store whose
10691 name end in @file{.drv}---these files are referred to as @dfn{derivation
10692 paths}. Derivations paths can be passed to the @code{build-derivations}
10693 procedure to perform the build actions they prescribe (@pxref{The
10696 @cindex fixed-output derivations
10697 Operations such as file downloads and version-control checkouts for
10698 which the expected content hash is known in advance are modeled as
10699 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
10700 of a fixed-output derivation are independent of its inputs---e.g., a
10701 source code download produces the same result regardless of the download
10702 method and tools being used.
10705 @cindex run-time dependencies
10706 @cindex dependencies, run-time
10707 The outputs of derivations---i.e., the build results---have a set of
10708 @dfn{references}, as reported by the @code{references} RPC or the
10709 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
10710 are the set of run-time dependencies of the build results. References are a
10711 subset of the inputs of the derivation; this subset is automatically computed
10712 by the build daemon by scanning all the files in the outputs.
10714 The @code{(guix derivations)} module provides a representation of
10715 derivations as Scheme objects, along with procedures to create and
10716 otherwise manipulate derivations. The lowest-level primitive to create
10717 a derivation is the @code{derivation} procedure:
10719 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
10720 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
10721 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
10722 [#:system (%current-system)] [#:references-graphs #f] @
10723 [#:allowed-references #f] [#:disallowed-references #f] @
10724 [#:leaked-env-vars #f] [#:local-build? #f] @
10725 [#:substitutable? #t] [#:properties '()]
10726 Build a derivation with the given arguments, and return the resulting
10727 @code{<derivation>} object.
10729 When @var{hash} and @var{hash-algo} are given, a
10730 @dfn{fixed-output derivation} is created---i.e., one whose result is
10731 known in advance, such as a file download. If, in addition,
10732 @var{recursive?} is true, then that fixed output may be an executable
10733 file or a directory and @var{hash} must be the hash of an archive
10734 containing this output.
10736 When @var{references-graphs} is true, it must be a list of file
10737 name/store path pairs. In that case, the reference graph of each store
10738 path is exported in the build environment in the corresponding file, in
10739 a simple text format.
10741 When @var{allowed-references} is true, it must be a list of store items
10742 or outputs that the derivation's output may refer to. Likewise,
10743 @var{disallowed-references}, if true, must be a list of things the
10744 outputs may @emph{not} refer to.
10746 When @var{leaked-env-vars} is true, it must be a list of strings
10747 denoting environment variables that are allowed to ``leak'' from the
10748 daemon's environment to the build environment. This is only applicable
10749 to fixed-output derivations---i.e., when @var{hash} is true. The main
10750 use is to allow variables such as @code{http_proxy} to be passed to
10751 derivations that download files.
10753 When @var{local-build?} is true, declare that the derivation is not a
10754 good candidate for offloading and should rather be built locally
10755 (@pxref{Daemon Offload Setup}). This is the case for small derivations
10756 where the costs of data transfers would outweigh the benefits.
10758 When @var{substitutable?} is false, declare that substitutes of the
10759 derivation's output should not be used (@pxref{Substitutes}). This is
10760 useful, for instance, when building packages that capture details of the
10761 host CPU instruction set.
10763 @var{properties} must be an association list describing ``properties'' of the
10764 derivation. It is kept as-is, uninterpreted, in the derivation.
10768 Here's an example with a shell script as its builder, assuming
10769 @var{store} is an open connection to the daemon, and @var{bash} points
10770 to a Bash executable in the store:
10773 (use-modules (guix utils)
10775 (guix derivations))
10777 (let ((builder ; add the Bash script to the store
10778 (add-text-to-store store "my-builder.sh"
10779 "echo hello world > $out\n" '())))
10780 (derivation store "foo"
10781 bash `("-e" ,builder)
10782 #:inputs `((,bash) (,builder))
10783 #:env-vars '(("HOME" . "/homeless"))))
10784 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
10787 As can be guessed, this primitive is cumbersome to use directly. A
10788 better approach is to write build scripts in Scheme, of course! The
10789 best course of action for that is to write the build code as a
10790 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
10791 information, @pxref{G-Expressions}.
10793 Once upon a time, @code{gexp->derivation} did not exist and constructing
10794 derivations with build code written in Scheme was achieved with
10795 @code{build-expression->derivation}, documented below. This procedure
10796 is now deprecated in favor of the much nicer @code{gexp->derivation}.
10798 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
10799 @var{name} @var{exp} @
10800 [#:system (%current-system)] [#:inputs '()] @
10801 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
10802 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
10803 [#:references-graphs #f] [#:allowed-references #f] @
10804 [#:disallowed-references #f] @
10805 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
10806 Return a derivation that executes Scheme expression @var{exp} as a
10807 builder for derivation @var{name}. @var{inputs} must be a list of
10808 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
10809 @code{"out"} is assumed. @var{modules} is a list of names of Guile
10810 modules from the current search path to be copied in the store,
10811 compiled, and made available in the load path during the execution of
10812 @var{exp}---e.g., @code{((guix build utils) (guix build
10813 gnu-build-system))}.
10815 @var{exp} is evaluated in an environment where @code{%outputs} is bound
10816 to a list of output/path pairs, and where @code{%build-inputs} is bound
10817 to a list of string/output-path pairs made from @var{inputs}.
10818 Optionally, @var{env-vars} is a list of string pairs specifying the name
10819 and value of environment variables visible to the builder. The builder
10820 terminates by passing the result of @var{exp} to @code{exit}; thus, when
10821 @var{exp} returns @code{#f}, the build is considered to have failed.
10823 @var{exp} is built using @var{guile-for-build} (a derivation). When
10824 @var{guile-for-build} is omitted or is @code{#f}, the value of the
10825 @code{%guile-for-build} fluid is used instead.
10827 See the @code{derivation} procedure for the meaning of
10828 @var{references-graphs}, @var{allowed-references},
10829 @var{disallowed-references}, @var{local-build?}, and
10830 @var{substitutable?}.
10834 Here's an example of a single-output derivation that creates a directory
10835 containing one file:
10838 (let ((builder '(let ((out (assoc-ref %outputs "out")))
10839 (mkdir out) ; create /gnu/store/@dots{}-goo
10840 (call-with-output-file (string-append out "/test")
10842 (display '(hello guix) p))))))
10843 (build-expression->derivation store "goo" builder))
10845 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
10849 @node The Store Monad
10850 @section The Store Monad
10854 The procedures that operate on the store described in the previous
10855 sections all take an open connection to the build daemon as their first
10856 argument. Although the underlying model is functional, they either have
10857 side effects or depend on the current state of the store.
10859 The former is inconvenient: the connection to the build daemon has to be
10860 carried around in all those functions, making it impossible to compose
10861 functions that do not take that parameter with functions that do. The
10862 latter can be problematic: since store operations have side effects
10863 and/or depend on external state, they have to be properly sequenced.
10865 @cindex monadic values
10866 @cindex monadic functions
10867 This is where the @code{(guix monads)} module comes in. This module
10868 provides a framework for working with @dfn{monads}, and a particularly
10869 useful monad for our uses, the @dfn{store monad}. Monads are a
10870 construct that allows two things: associating ``context'' with values
10871 (in our case, the context is the store), and building sequences of
10872 computations (here computations include accesses to the store). Values
10873 in a monad---values that carry this additional context---are called
10874 @dfn{monadic values}; procedures that return such values are called
10875 @dfn{monadic procedures}.
10877 Consider this ``normal'' procedure:
10880 (define (sh-symlink store)
10881 ;; Return a derivation that symlinks the 'bash' executable.
10882 (let* ((drv (package-derivation store bash))
10883 (out (derivation->output-path drv))
10884 (sh (string-append out "/bin/bash")))
10885 (build-expression->derivation store "sh"
10886 `(symlink ,sh %output))))
10889 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
10890 as a monadic function:
10893 (define (sh-symlink)
10894 ;; Same, but return a monadic value.
10895 (mlet %store-monad ((drv (package->derivation bash)))
10896 (gexp->derivation "sh"
10897 #~(symlink (string-append #$drv "/bin/bash")
10901 There are several things to note in the second version: the @code{store}
10902 parameter is now implicit and is ``threaded'' in the calls to the
10903 @code{package->derivation} and @code{gexp->derivation} monadic
10904 procedures, and the monadic value returned by @code{package->derivation}
10905 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
10907 As it turns out, the call to @code{package->derivation} can even be
10908 omitted since it will take place implicitly, as we will see later
10909 (@pxref{G-Expressions}):
10912 (define (sh-symlink)
10913 (gexp->derivation "sh"
10914 #~(symlink (string-append #$bash "/bin/bash")
10919 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
10920 @c for the funny quote.
10921 Calling the monadic @code{sh-symlink} has no effect. As someone once
10922 said, ``you exit a monad like you exit a building on fire: by running''.
10923 So, to exit the monad and get the desired effect, one must use
10924 @code{run-with-store}:
10927 (run-with-store (open-connection) (sh-symlink))
10928 @result{} /gnu/store/...-sh-symlink
10931 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
10932 new ``commands'' to make it easier to deal with monadic procedures:
10933 @code{run-in-store}, and @code{enter-store-monad} (@pxref{Using Guix
10934 Interactively}). The former is used
10935 to ``run'' a single monadic value through the store:
10938 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
10939 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
10942 The latter enters a recursive REPL, where all the return values are
10943 automatically run through the store:
10946 scheme@@(guile-user)> ,enter-store-monad
10947 store-monad@@(guile-user) [1]> (package->derivation hello)
10948 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
10949 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
10950 $3 = "/gnu/store/@dots{}-foo"
10951 store-monad@@(guile-user) [1]> ,q
10952 scheme@@(guile-user)>
10956 Note that non-monadic values cannot be returned in the
10957 @code{store-monad} REPL.
10959 Other meta-commands are available at the REPL, such as @code{,build} to
10960 build a file-like object (@pxref{Using Guix Interactively}).
10962 The main syntactic forms to deal with monads in general are provided by
10963 the @code{(guix monads)} module and are described below.
10965 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
10966 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
10970 @deffn {Scheme Syntax} return @var{val}
10971 Return a monadic value that encapsulates @var{val}.
10974 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
10975 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
10976 procedures @var{mproc}@dots{}@footnote{This operation is commonly
10977 referred to as ``bind'', but that name denotes an unrelated procedure in
10978 Guile. Thus we use this somewhat cryptic symbol inherited from the
10979 Haskell language.}. There can be one @var{mproc} or several of them, as
10984 (with-monad %state-monad
10986 (lambda (x) (return (+ 1 x)))
10987 (lambda (x) (return (* 2 x)))))
10991 @result{} some-state
10995 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
10997 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
10999 Bind the variables @var{var} to the monadic values @var{mval} in
11000 @var{body}, which is a sequence of expressions. As with the bind
11001 operator, this can be thought of as ``unpacking'' the raw, non-monadic
11002 value ``contained'' in @var{mval} and making @var{var} refer to that
11003 raw, non-monadic value within the scope of the @var{body}. The form
11004 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
11005 @var{val}, as per @code{let}. The binding operations occur in sequence
11006 from left to right. The last expression of @var{body} must be a monadic
11007 expression, and its result will become the result of the @code{mlet} or
11008 @code{mlet*} when run in the @var{monad}.
11010 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
11011 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
11014 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
11015 Bind @var{mexp} and the following monadic expressions in sequence,
11016 returning the result of the last expression. Every expression in the
11017 sequence must be a monadic expression.
11019 This is akin to @code{mlet}, except that the return values of the
11020 monadic expressions are ignored. In that sense, it is analogous to
11021 @code{begin}, but applied to monadic expressions.
11024 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
11025 When @var{condition} is true, evaluate the sequence of monadic
11026 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
11027 @var{condition} is false, return @code{*unspecified*} in the current
11028 monad. Every expression in the sequence must be a monadic expression.
11031 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
11032 When @var{condition} is false, evaluate the sequence of monadic
11033 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
11034 @var{condition} is true, return @code{*unspecified*} in the current
11035 monad. Every expression in the sequence must be a monadic expression.
11038 @cindex state monad
11039 The @code{(guix monads)} module provides the @dfn{state monad}, which
11040 allows an additional value---the state---to be @emph{threaded} through
11041 monadic procedure calls.
11043 @defvr {Scheme Variable} %state-monad
11044 The state monad. Procedures in the state monad can access and change
11045 the state that is threaded.
11047 Consider the example below. The @code{square} procedure returns a value
11048 in the state monad. It returns the square of its argument, but also
11049 increments the current state value:
11053 (mlet %state-monad ((count (current-state)))
11054 (mbegin %state-monad
11055 (set-current-state (+ 1 count))
11056 (return (* x x)))))
11058 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
11063 When ``run'' through @code{%state-monad}, we obtain that additional state
11064 value, which is the number of @code{square} calls.
11067 @deffn {Monadic Procedure} current-state
11068 Return the current state as a monadic value.
11071 @deffn {Monadic Procedure} set-current-state @var{value}
11072 Set the current state to @var{value} and return the previous state as a
11076 @deffn {Monadic Procedure} state-push @var{value}
11077 Push @var{value} to the current state, which is assumed to be a list,
11078 and return the previous state as a monadic value.
11081 @deffn {Monadic Procedure} state-pop
11082 Pop a value from the current state and return it as a monadic value.
11083 The state is assumed to be a list.
11086 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
11087 Run monadic value @var{mval} starting with @var{state} as the initial
11088 state. Return two values: the resulting value, and the resulting state.
11091 The main interface to the store monad, provided by the @code{(guix
11092 store)} module, is as follows.
11094 @defvr {Scheme Variable} %store-monad
11095 The store monad---an alias for @code{%state-monad}.
11097 Values in the store monad encapsulate accesses to the store. When its
11098 effect is needed, a value of the store monad must be ``evaluated'' by
11099 passing it to the @code{run-with-store} procedure (see below).
11102 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
11103 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
11104 open store connection.
11107 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
11108 Return as a monadic value the absolute file name in the store of the file
11109 containing @var{text}, a string. @var{references} is a list of store items that the
11110 resulting text file refers to; it defaults to the empty list.
11113 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
11114 Return as a monadic value the absolute file name in the store of the file
11115 containing @var{data}, a bytevector. @var{references} is a list of store
11116 items that the resulting binary file refers to; it defaults to the empty list.
11119 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
11120 [#:recursive? #t] [#:select? (const #t)]
11121 Return the name of @var{file} once interned in the store. Use
11122 @var{name} as its store name, or the basename of @var{file} if
11123 @var{name} is omitted.
11125 When @var{recursive?} is true, the contents of @var{file} are added
11126 recursively; if @var{file} designates a flat file and @var{recursive?}
11127 is true, its contents are added, and its permission bits are kept.
11129 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
11130 @var{stat})} for each directory entry, where @var{file} is the entry's
11131 absolute file name and @var{stat} is the result of @code{lstat}; exclude
11132 entries for which @var{select?} does not return true.
11134 The example below adds a file to the store, under two different names:
11137 (run-with-store (open-connection)
11138 (mlet %store-monad ((a (interned-file "README"))
11139 (b (interned-file "README" "LEGU-MIN")))
11140 (return (list a b))))
11142 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
11147 The @code{(guix packages)} module exports the following package-related
11148 monadic procedures:
11150 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
11151 [#:system (%current-system)] [#:target #f] @
11153 Return as a monadic
11154 value in the absolute file name of @var{file} within the @var{output}
11155 directory of @var{package}. When @var{file} is omitted, return the name
11156 of the @var{output} directory of @var{package}. When @var{target} is
11157 true, use it as a cross-compilation target triplet.
11159 Note that this procedure does @emph{not} build @var{package}. Thus, the
11160 result might or might not designate an existing file. We recommend not
11161 using this procedure unless you know what you are doing.
11164 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
11165 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
11166 @var{target} [@var{system}]
11167 Monadic version of @code{package-derivation} and
11168 @code{package-cross-derivation} (@pxref{Defining Packages}).
11172 @node G-Expressions
11173 @section G-Expressions
11175 @cindex G-expression
11176 @cindex build code quoting
11177 So we have ``derivations'', which represent a sequence of build actions
11178 to be performed to produce an item in the store (@pxref{Derivations}).
11179 These build actions are performed when asking the daemon to actually
11180 build the derivations; they are run by the daemon in a container
11181 (@pxref{Invoking guix-daemon}).
11183 @cindex code staging
11184 @cindex staging, of code
11185 @cindex strata of code
11186 It should come as no surprise that we like to write these build actions
11187 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
11188 code@footnote{The term @dfn{stratum} in this context was coined by
11189 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
11190 Kiselyov, who has written insightful
11191 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
11192 on this topic}, refers to this kind of code generation as
11193 @dfn{staging}.}: the ``host code''---code that defines packages, talks
11194 to the daemon, etc.---and the ``build code''---code that actually
11195 performs build actions, such as making directories, invoking
11196 @command{make}, and so on (@pxref{Build Phases}).
11198 To describe a derivation and its build actions, one typically needs to
11199 embed build code inside host code. It boils down to manipulating build
11200 code as data, and the homoiconicity of Scheme---code has a direct
11201 representation as data---comes in handy for that. But we need more than
11202 the normal @code{quasiquote} mechanism in Scheme to construct build
11205 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
11206 S-expressions adapted to build expressions. G-expressions, or
11207 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
11208 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
11209 @code{#$}, and @code{#$@@}), which are comparable to
11210 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
11211 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
11212 GNU Guile Reference Manual}). However, there are major differences:
11216 Gexps are meant to be written to a file and run or manipulated by other
11220 When a high-level object such as a package or derivation is unquoted
11221 inside a gexp, the result is as if its output file name had been
11225 Gexps carry information about the packages or derivations they refer to,
11226 and these dependencies are automatically added as inputs to the build
11227 processes that use them.
11230 @cindex lowering, of high-level objects in gexps
11231 This mechanism is not limited to package and derivation
11232 objects: @dfn{compilers} able to ``lower'' other high-level objects to
11233 derivations or files in the store can be defined,
11234 such that these objects can also be inserted
11235 into gexps. For example, a useful type of high-level objects that can be
11236 inserted in a gexp is ``file-like objects'', which make it easy to
11237 add files to the store and to refer to them in
11238 derivations and such (see @code{local-file} and @code{plain-file}
11241 To illustrate the idea, here is an example of a gexp:
11248 (symlink (string-append #$coreutils "/bin/ls")
11252 This gexp can be passed to @code{gexp->derivation}; we obtain a
11253 derivation that builds a directory containing exactly one symlink to
11254 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
11257 (gexp->derivation "the-thing" build-exp)
11260 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
11261 substituted to the reference to the @var{coreutils} package in the
11262 actual build code, and @var{coreutils} is automatically made an input to
11263 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
11264 output)}) is replaced by a string containing the directory name of the
11265 output of the derivation.
11267 @cindex cross compilation
11268 In a cross-compilation context, it is useful to distinguish between
11269 references to the @emph{native} build of a package---that can run on the
11270 host---versus references to cross builds of a package. To that end, the
11271 @code{#+} plays the same role as @code{#$}, but is a reference to a
11272 native package build:
11275 (gexp->derivation "vi"
11278 (mkdir (string-append #$output "/bin"))
11279 (system* (string-append #+coreutils "/bin/ln")
11281 (string-append #$emacs "/bin/emacs")
11282 (string-append #$output "/bin/vi")))
11283 #:target "aarch64-linux-gnu")
11287 In the example above, the native build of @var{coreutils} is used, so
11288 that @command{ln} can actually run on the host; but then the
11289 cross-compiled build of @var{emacs} is referenced.
11291 @cindex imported modules, for gexps
11292 @findex with-imported-modules
11293 Another gexp feature is @dfn{imported modules}: sometimes you want to be
11294 able to use certain Guile modules from the ``host environment'' in the
11295 gexp, so those modules should be imported in the ``build environment''.
11296 The @code{with-imported-modules} form allows you to express that:
11299 (let ((build (with-imported-modules '((guix build utils))
11301 (use-modules (guix build utils))
11302 (mkdir-p (string-append #$output "/bin"))))))
11303 (gexp->derivation "empty-dir"
11306 (display "success!\n")
11311 In this example, the @code{(guix build utils)} module is automatically
11312 pulled into the isolated build environment of our gexp, such that
11313 @code{(use-modules (guix build utils))} works as expected.
11315 @cindex module closure
11316 @findex source-module-closure
11317 Usually you want the @emph{closure} of the module to be imported---i.e.,
11318 the module itself and all the modules it depends on---rather than just
11319 the module; failing to do that, attempts to use the module will fail
11320 because of missing dependent modules. The @code{source-module-closure}
11321 procedure computes the closure of a module by looking at its source file
11322 headers, which comes in handy in this case:
11325 (use-modules (guix modules)) ;for 'source-module-closure'
11327 (with-imported-modules (source-module-closure
11328 '((guix build utils)
11329 (gnu build image)))
11330 (gexp->derivation "something-with-vms"
11332 (use-modules (guix build utils)
11337 @cindex extensions, for gexps
11338 @findex with-extensions
11339 In the same vein, sometimes you want to import not just pure-Scheme
11340 modules, but also ``extensions'' such as Guile bindings to C libraries
11341 or other ``full-blown'' packages. Say you need the @code{guile-json}
11342 package available on the build side, here's how you would do it:
11345 (use-modules (gnu packages guile)) ;for 'guile-json'
11347 (with-extensions (list guile-json)
11348 (gexp->derivation "something-with-json"
11350 (use-modules (json))
11354 The syntactic form to construct gexps is summarized below.
11356 @deffn {Scheme Syntax} #~@var{exp}
11357 @deffnx {Scheme Syntax} (gexp @var{exp})
11358 Return a G-expression containing @var{exp}. @var{exp} may contain one
11359 or more of the following forms:
11363 @itemx (ungexp @var{obj})
11364 Introduce a reference to @var{obj}. @var{obj} may have one of the
11365 supported types, for example a package or a
11366 derivation, in which case the @code{ungexp} form is replaced by its
11367 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
11369 If @var{obj} is a list, it is traversed and references to supported
11370 objects are substituted similarly.
11372 If @var{obj} is another gexp, its contents are inserted and its
11373 dependencies are added to those of the containing gexp.
11375 If @var{obj} is another kind of object, it is inserted as is.
11377 @item #$@var{obj}:@var{output}
11378 @itemx (ungexp @var{obj} @var{output})
11379 This is like the form above, but referring explicitly to the
11380 @var{output} of @var{obj}---this is useful when @var{obj} produces
11381 multiple outputs (@pxref{Packages with Multiple Outputs}).
11384 @itemx #+@var{obj}:output
11385 @itemx (ungexp-native @var{obj})
11386 @itemx (ungexp-native @var{obj} @var{output})
11387 Same as @code{ungexp}, but produces a reference to the @emph{native}
11388 build of @var{obj} when used in a cross compilation context.
11390 @item #$output[:@var{output}]
11391 @itemx (ungexp output [@var{output}])
11392 Insert a reference to derivation output @var{output}, or to the main
11393 output when @var{output} is omitted.
11395 This only makes sense for gexps passed to @code{gexp->derivation}.
11397 @item #$@@@var{lst}
11398 @itemx (ungexp-splicing @var{lst})
11399 Like the above, but splices the contents of @var{lst} inside the
11402 @item #+@@@var{lst}
11403 @itemx (ungexp-native-splicing @var{lst})
11404 Like the above, but refers to native builds of the objects listed in
11409 G-expressions created by @code{gexp} or @code{#~} are run-time objects
11410 of the @code{gexp?} type (see below).
11413 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
11414 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
11415 in their execution environment.
11417 Each item in @var{modules} can be the name of a module, such as
11418 @code{(guix build utils)}, or it can be a module name, followed by an
11419 arrow, followed by a file-like object:
11422 `((guix build utils)
11424 ((guix config) => ,(scheme-file "config.scm"
11425 #~(define-module @dots{}))))
11429 In the example above, the first two modules are taken from the search
11430 path, and the last one is created from the given file-like object.
11432 This form has @emph{lexical} scope: it has an effect on the gexps
11433 directly defined in @var{body}@dots{}, but not on those defined, say, in
11434 procedures called from @var{body}@dots{}.
11437 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
11438 Mark the gexps defined in @var{body}@dots{} as requiring
11439 @var{extensions} in their build and execution environment.
11440 @var{extensions} is typically a list of package objects such as those
11441 defined in the @code{(gnu packages guile)} module.
11443 Concretely, the packages listed in @var{extensions} are added to the
11444 load path while compiling imported modules in @var{body}@dots{}; they
11445 are also added to the load path of the gexp returned by
11449 @deffn {Scheme Procedure} gexp? @var{obj}
11450 Return @code{#t} if @var{obj} is a G-expression.
11453 G-expressions are meant to be written to disk, either as code building
11454 some derivation, or as plain files in the store. The monadic procedures
11455 below allow you to do that (@pxref{The Store Monad}, for more
11456 information about monads).
11458 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
11459 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
11460 [#:hash #f] [#:hash-algo #f] @
11461 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
11462 [#:module-path @code{%load-path}] @
11463 [#:effective-version "2.2"] @
11464 [#:references-graphs #f] [#:allowed-references #f] @
11465 [#:disallowed-references #f] @
11466 [#:leaked-env-vars #f] @
11467 [#:script-name (string-append @var{name} "-builder")] @
11468 [#:deprecation-warnings #f] @
11469 [#:local-build? #f] [#:substitutable? #t] @
11470 [#:properties '()] [#:guile-for-build #f]
11471 Return a derivation @var{name} that runs @var{exp} (a gexp) with
11472 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
11473 stored in a file called @var{script-name}. When @var{target} is true,
11474 it is used as the cross-compilation target triplet for packages referred
11477 @var{modules} is deprecated in favor of @code{with-imported-modules}.
11479 make @var{modules} available in the evaluation context of @var{exp};
11480 @var{modules} is a list of names of Guile modules searched in
11481 @var{module-path} to be copied in the store, compiled, and made available in
11482 the load path during the execution of @var{exp}---e.g., @code{((guix
11483 build utils) (guix build gnu-build-system))}.
11485 @var{effective-version} determines the string to use when adding extensions of
11486 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
11488 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
11491 When @var{references-graphs} is true, it must be a list of tuples of one of the
11495 (@var{file-name} @var{package})
11496 (@var{file-name} @var{package} @var{output})
11497 (@var{file-name} @var{derivation})
11498 (@var{file-name} @var{derivation} @var{output})
11499 (@var{file-name} @var{store-item})
11502 The right-hand-side of each element of @var{references-graphs} is automatically made
11503 an input of the build process of @var{exp}. In the build environment, each
11504 @var{file-name} contains the reference graph of the corresponding item, in a simple
11507 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
11508 In the latter case, the list denotes store items that the result is allowed to
11509 refer to. Any reference to another store item will lead to a build error.
11510 Similarly for @var{disallowed-references}, which can list items that must not be
11511 referenced by the outputs.
11513 @var{deprecation-warnings} determines whether to show deprecation warnings while
11514 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
11516 The other arguments are as for @code{derivation} (@pxref{Derivations}).
11519 @cindex file-like objects
11520 The @code{local-file}, @code{plain-file}, @code{computed-file},
11521 @code{program-file}, and @code{scheme-file} procedures below return
11522 @dfn{file-like objects}. That is, when unquoted in a G-expression,
11523 these objects lead to a file in the store. Consider this G-expression:
11526 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
11527 #$(local-file "/tmp/my-nscd.conf"))
11530 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
11531 to the store. Once expanded, for instance @i{via}
11532 @code{gexp->derivation}, the G-expression refers to that copy under
11533 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
11534 does not have any effect on what the G-expression does.
11535 @code{plain-file} can be used similarly; it differs in that the file
11536 content is directly passed as a string.
11538 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
11539 [#:recursive? #f] [#:select? (const #t)]
11540 Return an object representing local file @var{file} to add to the store;
11541 this object can be used in a gexp. If @var{file} is a literal string
11542 denoting a relative file name, it is looked up relative to the source
11543 file where it appears; if @var{file} is not a literal string, it is
11544 looked up relative to the current working directory at run time.
11545 @var{file} will be added to the store under @var{name}--by default the
11546 base name of @var{file}.
11548 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
11549 designates a flat file and @var{recursive?} is true, its contents are added, and its
11550 permission bits are kept.
11552 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
11553 @var{stat})} for each directory entry, where @var{file} is the entry's
11554 absolute file name and @var{stat} is the result of @code{lstat}; exclude
11555 entries for which @var{select?} does not return true.
11557 This is the declarative counterpart of the @code{interned-file} monadic
11558 procedure (@pxref{The Store Monad, @code{interned-file}}).
11561 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
11562 Return an object representing a text file called @var{name} with the given
11563 @var{content} (a string or a bytevector) to be added to the store.
11565 This is the declarative counterpart of @code{text-file}.
11568 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
11569 [#:local-build? #t]
11571 Return an object representing the store item @var{name}, a file or
11572 directory computed by @var{gexp}. When @var{local-build?} is true (the
11573 default), the derivation is built locally. @var{options} is a list of
11574 additional arguments to pass to @code{gexp->derivation}.
11576 This is the declarative counterpart of @code{gexp->derivation}.
11579 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
11580 [#:guile (default-guile)] [#:module-path %load-path] @
11581 [#:system (%current-system)] [#:target #f]
11582 Return an executable script @var{name} that runs @var{exp} using
11583 @var{guile}, with @var{exp}'s imported modules in its search path.
11584 Look up @var{exp}'s modules in @var{module-path}.
11586 The example below builds a script that simply invokes the @command{ls}
11590 (use-modules (guix gexp) (gnu packages base))
11592 (gexp->script "list-files"
11593 #~(execl #$(file-append coreutils "/bin/ls")
11597 When ``running'' it through the store (@pxref{The Store Monad,
11598 @code{run-with-store}}), we obtain a derivation that produces an
11599 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
11602 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
11604 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
11608 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
11609 [#:guile #f] [#:module-path %load-path]
11610 Return an object representing the executable store item @var{name} that
11611 runs @var{gexp}. @var{guile} is the Guile package used to execute that
11612 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
11614 This is the declarative counterpart of @code{gexp->script}.
11617 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
11618 [#:set-load-path? #t] [#:module-path %load-path] @
11620 [#:guile (default-guile)]
11621 Return a derivation that builds a file @var{name} containing @var{exp}.
11622 When @var{splice?} is true, @var{exp} is considered to be a list of
11623 expressions that will be spliced in the resulting file.
11625 When @var{set-load-path?} is true, emit code in the resulting file to
11626 set @code{%load-path} and @code{%load-compiled-path} to honor
11627 @var{exp}'s imported modules. Look up @var{exp}'s modules in
11630 The resulting file holds references to all the dependencies of @var{exp}
11631 or a subset thereof.
11634 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
11635 [#:splice? #f] [#:set-load-path? #t]
11636 Return an object representing the Scheme file @var{name} that contains
11639 This is the declarative counterpart of @code{gexp->file}.
11642 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
11643 Return as a monadic value a derivation that builds a text file
11644 containing all of @var{text}. @var{text} may list, in addition to
11645 strings, objects of any type that can be used in a gexp: packages,
11646 derivations, local file objects, etc. The resulting store file holds
11647 references to all these.
11649 This variant should be preferred over @code{text-file} anytime the file
11650 to create will reference items from the store. This is typically the
11651 case when building a configuration file that embeds store file names,
11655 (define (profile.sh)
11656 ;; Return the name of a shell script in the store that
11657 ;; initializes the 'PATH' environment variable.
11658 (text-file* "profile.sh"
11659 "export PATH=" coreutils "/bin:"
11660 grep "/bin:" sed "/bin\n"))
11663 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
11664 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
11665 preventing them from being garbage-collected during its lifetime.
11668 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
11669 Return an object representing store file @var{name} containing
11670 @var{text}. @var{text} is a sequence of strings and file-like objects,
11674 (mixed-text-file "profile"
11675 "export PATH=" coreutils "/bin:" grep "/bin")
11678 This is the declarative counterpart of @code{text-file*}.
11681 @deffn {Scheme Procedure} file-union @var{name} @var{files}
11682 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
11683 Each item in @var{files} must be a two-element list where the first element is the
11684 file name to use in the new directory, and the second element is a gexp
11685 denoting the target file. Here's an example:
11689 `(("hosts" ,(plain-file "hosts"
11690 "127.0.0.1 localhost"))
11691 ("bashrc" ,(plain-file "bashrc"
11692 "alias ls='ls --color=auto'"))))
11695 This yields an @code{etc} directory containing these two files.
11698 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
11699 Return a directory that is the union of @var{things}, where @var{things} is a list of
11700 file-like objects denoting directories. For example:
11703 (directory-union "guile+emacs" (list guile emacs))
11706 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
11709 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
11710 Return a file-like object that expands to the concatenation of @var{obj}
11711 and @var{suffix}, where @var{obj} is a lowerable object and each
11712 @var{suffix} is a string.
11714 As an example, consider this gexp:
11717 (gexp->script "run-uname"
11718 #~(system* #$(file-append coreutils
11722 The same effect could be achieved with:
11725 (gexp->script "run-uname"
11726 #~(system* (string-append #$coreutils
11730 There is one difference though: in the @code{file-append} case, the
11731 resulting script contains the absolute file name as a string, whereas in
11732 the second case, the resulting script contains a @code{(string-append
11733 @dots{})} expression to construct the file name @emph{at run time}.
11736 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
11737 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
11738 Bind @var{system} to the currently targeted system---e.g.,
11739 @code{"x86_64-linux"}---within @var{body}.
11741 In the second case, additionally bind @var{target} to the current
11742 cross-compilation target---a GNU triplet such as
11743 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
11746 @code{let-system} is useful in the occasional case where the object
11747 spliced into the gexp depends on the target system, as in this example:
11751 #+(let-system system
11752 (cond ((string-prefix? "armhf-" system)
11753 (file-append qemu "/bin/qemu-system-arm"))
11754 ((string-prefix? "x86_64-" system)
11755 (file-append qemu "/bin/qemu-system-x86_64"))
11757 (error "dunno!"))))
11758 "-net" "user" #$image)
11762 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
11763 This macro is similar to the @code{parameterize} form for
11764 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
11765 Guile Reference Manual}). The key difference is that it takes effect
11766 when the file-like object returned by @var{exp} is lowered to a
11767 derivation or store item.
11769 A typical use of @code{with-parameters} is to force the system in effect
11770 for a given object:
11773 (with-parameters ((%current-system "i686-linux"))
11777 The example above returns an object that corresponds to the i686 build
11778 of Coreutils, regardless of the current value of @code{%current-system}.
11782 Of course, in addition to gexps embedded in ``host'' code, there are
11783 also modules containing build tools. To make it clear that they are
11784 meant to be used in the build stratum, these modules are kept in the
11785 @code{(guix build @dots{})} name space.
11787 @cindex lowering, of high-level objects in gexps
11788 Internally, high-level objects are @dfn{lowered}, using their compiler,
11789 to either derivations or store items. For instance, lowering a package
11790 yields a derivation, and lowering a @code{plain-file} yields a store
11791 item. This is achieved using the @code{lower-object} monadic procedure.
11793 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
11795 Return as a value in @code{%store-monad} the derivation or store item
11796 corresponding to @var{obj} for @var{system}, cross-compiling for
11797 @var{target} if @var{target} is true. @var{obj} must be an object that
11798 has an associated gexp compiler, such as a @code{<package>}.
11801 @deffn {Procedure} gexp->approximate-sexp @var{gexp}
11802 Sometimes, it may be useful to convert a G-exp into a S-exp. For
11803 example, some linters (@pxref{Invoking guix lint}) peek into the build
11804 phases of a package to detect potential problems. This conversion can
11805 be achieved with this procedure. However, some information can be lost
11806 in the process. More specifically, lowerable objects will be silently
11807 replaced with some arbitrary object -- currently the list
11808 @code{(*approximate*)}, but this may change.
11811 @node Invoking guix repl
11812 @section Invoking @command{guix repl}
11814 @cindex @command{guix repl}
11815 @cindex REPL, read-eval-print loop, script
11816 The @command{guix repl} command makes it easier to program Guix in Guile
11817 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
11818 programming (@pxref{Using Guile Interactively,,, guile,
11819 GNU Guile Reference Manual}), or by running Guile scripts
11820 (@pxref{Running Guile Scripts,,, guile,
11821 GNU Guile Reference Manual}).
11822 Compared to just launching the @command{guile}
11823 command, @command{guix repl} guarantees that all the Guix modules and all its
11824 dependencies are available in the search path.
11826 The general syntax is:
11829 guix repl @var{options} [@var{file} @var{args}]
11832 When a @var{file} argument is provided, @var{file} is
11833 executed as a Guile scripts:
11836 guix repl my-script.scm
11839 To pass arguments to the script, use @code{--} to prevent them from
11840 being interpreted as arguments to @command{guix repl} itself:
11843 guix repl -- my-script.scm --input=foo.txt
11846 To make a script executable directly from the shell, using the guix
11847 executable that is on the user's search path, add the following two
11848 lines at the top of the script:
11851 @code{#!/usr/bin/env -S guix repl --}
11855 Without a file name argument, a Guile REPL is started, allowing for
11856 interactive use (@pxref{Using Guix Interactively}):
11860 scheme@@(guile-user)> ,use (gnu packages base)
11861 scheme@@(guile-user)> coreutils
11862 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
11866 In addition, @command{guix repl} implements a simple machine-readable REPL
11867 protocol for use by @code{(guix inferior)}, a facility to interact with
11868 @dfn{inferiors}, separate processes running a potentially different revision
11871 The available options are as follows:
11874 @item --type=@var{type}
11875 @itemx -t @var{type}
11876 Start a REPL of the given @var{TYPE}, which can be one of the following:
11880 This is default, and it spawns a standard full-featured Guile REPL.
11882 Spawn a REPL that uses the machine-readable protocol. This is the protocol
11883 that the @code{(guix inferior)} module speaks.
11886 @item --listen=@var{endpoint}
11887 By default, @command{guix repl} reads from standard input and writes to
11888 standard output. When this option is passed, it will instead listen for
11889 connections on @var{endpoint}. Here are examples of valid options:
11892 @item --listen=tcp:37146
11893 Accept connections on localhost on port 37146.
11895 @item --listen=unix:/tmp/socket
11896 Accept connections on the Unix-domain socket @file{/tmp/socket}.
11899 @item --load-path=@var{directory}
11900 @itemx -L @var{directory}
11901 Add @var{directory} to the front of the package module search path
11902 (@pxref{Package Modules}).
11904 This allows users to define their own packages and make them visible to
11905 the script or REPL.
11908 Inhibit loading of the @file{~/.guile} file. By default, that
11909 configuration file is loaded when spawning a @code{guile} REPL.
11912 @node Using Guix Interactively
11913 @section Using Guix Interactively
11915 @cindex interactive use
11916 @cindex REPL, read-eval-print loop
11917 The @command{guix repl} command gives you access to a warm and friendly
11918 @dfn{read-eval-print loop} (REPL) (@pxref{Invoking guix repl}). If
11919 you're getting into Guix programming---defining your own packages,
11920 writing manifests, defining services for Guix System or Guix Home,
11921 etc.---you will surely find it convenient to toy with ideas at the REPL.
11923 If you use Emacs, the most convenient way to do that is with Geiser
11924 (@pxref{The Perfect Setup}), but you do not have to use Emacs to enjoy
11925 the REPL@. When using @command{guix repl} or @command{guile} in the
11926 terminal, we recommend using Readline for completion and Colorized to
11927 get colorful output. To do that, you can run:
11930 guix install guile guile-readline guile-colorized
11934 ... and then create a @file{.guile} file in your home directory containing
11938 (use-modules (ice-9 readline) (ice-9 colorized))
11940 (activate-readline)
11941 (activate-colorized)
11944 The REPL lets you evaluate Scheme code; you type a Scheme expression at
11945 the prompt, and the REPL prints what it evaluates to:
11949 scheme@@(guix-user)> (+ 2 3)
11951 scheme@@(guix-user)> (string-append "a" "b")
11955 It becomes interesting when you start fiddling with Guix at the REPL.
11956 The first thing you'll want to do is to ``import'' the @code{(guix)}
11957 module, which gives access to the main part of the programming
11958 interface, and perhaps a bunch of useful Guix modules. You could type
11959 @code{(use-modules (guix))}, which is valid Scheme code to import a
11960 module (@pxref{Using Guile Modules,,, guile, GNU Guile Reference
11961 Manual}), but the REPL provides the @code{use} @dfn{command} as a
11962 shorthand notation (@pxref{REPL Commands,,, guile, GNU Guile Reference
11966 scheme@@(guix-user)> ,use (guix)
11967 scheme@@(guix-user)> ,use (gnu packages base)
11970 Notice that REPL commands are introduced by a leading comma. A REPL
11971 command like @code{use} is not valid Scheme code; it's interpreted
11972 specially by the REPL.
11974 Guix extends the Guile REPL with additional commands for convenience.
11975 Among those, the @code{build} command comes in handy: it ensures that
11976 the given file-like object is built, building it if needed, and returns
11977 its output file name(s). In the example below, we build the
11978 @code{coreutils} and @code{grep} packages, as well as a ``computed
11979 file'' (@pxref{G-Expressions, @code{computed-file}}), and we use the
11980 @code{scandir} procedure to list the files in Grep's @code{/bin}
11984 scheme@@(guix-user)> ,build coreutils
11985 $1 = "/gnu/store/@dots{}-coreutils-8.32-debug"
11986 $2 = "/gnu/store/@dots{}-coreutils-8.32"
11987 scheme@@(guix-user)> ,build grep
11988 $3 = "/gnu/store/@dots{}-grep-3.6"
11989 scheme@@(guix-user)> ,build (computed-file "x" #~(mkdir #$output))
11990 building /gnu/store/@dots{}-x.drv...
11991 $4 = "/gnu/store/@dots{}-x"
11992 scheme@@(guix-user)> ,use(ice-9 ftw)
11993 scheme@@(guix-user)> (scandir (string-append $3 "/bin"))
11994 $5 = ("." ".." "egrep" "fgrep" "grep")
11997 At a lower-level, a useful command is @code{lower}: it takes a file-like
11998 object and ``lowers'' it into a derivation (@pxref{Derivations}) or a
12002 scheme@@(guix-user)> ,lower grep
12003 $6 = #<derivation /gnu/store/@dots{}-grep-3.6.drv => /gnu/store/@dots{}-grep-3.6 7f0e639115f0>
12004 scheme@@(guix-user)> ,lower (plain-file "x" "Hello!")
12005 $7 = "/gnu/store/@dots{}-x"
12008 The full list of REPL commands can be seen by typing @code{,help guix}
12009 and is given below for reference.
12011 @deffn {REPL command} build @var{object}
12012 Lower @var{object} and build it if it's not already built, returning its
12013 output file name(s).
12016 @deffn {REPL command} lower @var{object}
12017 Lower @var{object} into a derivation or store file name and return it.
12020 @deffn {REPL command} verbosity @var{level}
12021 Change build verbosity to @var{level}.
12023 This is similar to the @option{--verbosity} command-line option
12024 (@pxref{Common Build Options}): level 0 means total silence, level 1
12025 shows build events only, and higher levels print build logs.
12028 @deffn {REPL command} run-in-store @var{exp}
12029 Run @var{exp}, a monadic expresssion, through the store monad.
12030 @xref{The Store Monad}, for more information.
12033 @deffn {REPL command} enter-store-monad
12034 Enter a new REPL to evaluate monadic expressions (@pxref{The Store
12035 Monad}). You can quit this ``inner'' REPL by typing @code{,q}.
12038 @c *********************************************************************
12042 This section describes Guix command-line utilities. Some of them are
12043 primarily targeted at developers and users who write new package
12044 definitions, while others are more generally useful. They complement
12045 the Scheme programming interface of Guix in a convenient way.
12048 * Invoking guix build:: Building packages from the command line.
12049 * Invoking guix edit:: Editing package definitions.
12050 * Invoking guix download:: Downloading a file and printing its hash.
12051 * Invoking guix hash:: Computing the cryptographic hash of a file.
12052 * Invoking guix import:: Importing package definitions.
12053 * Invoking guix refresh:: Updating package definitions.
12054 * Invoking guix style:: Styling package definitions.
12055 * Invoking guix lint:: Finding errors in package definitions.
12056 * Invoking guix size:: Profiling disk usage.
12057 * Invoking guix graph:: Visualizing the graph of packages.
12058 * Invoking guix publish:: Sharing substitutes.
12059 * Invoking guix challenge:: Challenging substitute servers.
12060 * Invoking guix copy:: Copying to and from a remote store.
12061 * Invoking guix container:: Process isolation.
12062 * Invoking guix weather:: Assessing substitute availability.
12063 * Invoking guix processes:: Listing client processes.
12066 @node Invoking guix build
12067 @section Invoking @command{guix build}
12069 @cindex package building
12070 @cindex @command{guix build}
12071 The @command{guix build} command builds packages or derivations and
12072 their dependencies, and prints the resulting store paths. Note that it
12073 does not modify the user's profile---this is the job of the
12074 @command{guix package} command (@pxref{Invoking guix package}). Thus,
12075 it is mainly useful for distribution developers.
12077 The general syntax is:
12080 guix build @var{options} @var{package-or-derivation}@dots{}
12083 As an example, the following command builds the latest versions of Emacs
12084 and of Guile, displays their build logs, and finally displays the
12085 resulting directories:
12088 guix build emacs guile
12091 Similarly, the following command builds all the available packages:
12094 guix build --quiet --keep-going \
12095 $(guix package -A | awk '@{ print $1 "@@" $2 @}')
12098 @var{package-or-derivation} may be either the name of a package found in
12099 the software distribution such as @code{coreutils} or
12100 @code{coreutils@@8.20}, or a derivation such as
12101 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
12102 package with the corresponding name (and optionally version) is searched
12103 for among the GNU distribution modules (@pxref{Package Modules}).
12105 Alternatively, the @option{--expression} option may be used to specify a
12106 Scheme expression that evaluates to a package; this is useful when
12107 disambiguating among several same-named packages or package variants is
12110 There may be zero or more @var{options}. The available options are
12111 described in the subsections below.
12114 * Common Build Options:: Build options for most commands.
12115 * Package Transformation Options:: Creating variants of packages.
12116 * Additional Build Options:: Options specific to 'guix build'.
12117 * Debugging Build Failures:: Real life packaging experience.
12120 @node Common Build Options
12121 @subsection Common Build Options
12123 A number of options that control the build process are common to
12124 @command{guix build} and other commands that can spawn builds, such as
12125 @command{guix package} or @command{guix archive}. These are the
12130 @item --load-path=@var{directory}
12131 @itemx -L @var{directory}
12132 Add @var{directory} to the front of the package module search path
12133 (@pxref{Package Modules}).
12135 This allows users to define their own packages and make them visible to
12136 the command-line tools.
12138 @item --keep-failed
12140 Keep the build tree of failed builds. Thus, if a build fails, its build
12141 tree is kept under @file{/tmp}, in a directory whose name is shown at
12142 the end of the build log. This is useful when debugging build issues.
12143 @xref{Debugging Build Failures}, for tips and tricks on how to debug
12146 This option implies @option{--no-offload}, and it has no effect when
12147 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
12148 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
12152 Keep going when some of the derivations fail to build; return only once
12153 all the builds have either completed or failed.
12155 The default behavior is to stop as soon as one of the specified
12156 derivations has failed.
12160 Do not build the derivations.
12162 @anchor{fallback-option}
12164 When substituting a pre-built binary fails, fall back to building
12165 packages locally (@pxref{Substitution Failure}).
12167 @item --substitute-urls=@var{urls}
12168 @anchor{client-substitute-urls}
12169 Consider @var{urls} the whitespace-separated list of substitute source
12170 URLs, overriding the default list of URLs of @command{guix-daemon}
12171 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
12173 This means that substitutes may be downloaded from @var{urls}, provided
12174 they are signed by a key authorized by the system administrator
12175 (@pxref{Substitutes}).
12177 When @var{urls} is the empty string, substitutes are effectively
12180 @item --no-substitutes
12181 Do not use substitutes for build products. That is, always build things
12182 locally instead of allowing downloads of pre-built binaries
12183 (@pxref{Substitutes}).
12186 Do not ``graft'' packages. In practice, this means that package updates
12187 available as grafts are not applied. @xref{Security Updates}, for more
12188 information on grafts.
12190 @item --rounds=@var{n}
12191 Build each derivation @var{n} times in a row, and raise an error if
12192 consecutive build results are not bit-for-bit identical.
12194 This is a useful way to detect non-deterministic builds processes.
12195 Non-deterministic build processes are a problem because they make it
12196 practically impossible for users to @emph{verify} whether third-party
12197 binaries are genuine. @xref{Invoking guix challenge}, for more.
12199 When used in conjunction with @option{--keep-failed}, the differing
12200 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
12201 This makes it easy to look for differences between the two results.
12204 Do not use offload builds to other machines (@pxref{Daemon Offload
12205 Setup}). That is, always build things locally instead of offloading
12206 builds to remote machines.
12208 @item --max-silent-time=@var{seconds}
12209 When the build or substitution process remains silent for more than
12210 @var{seconds}, terminate it and report a build failure.
12212 By default, the daemon's setting is honored (@pxref{Invoking
12213 guix-daemon, @option{--max-silent-time}}).
12215 @item --timeout=@var{seconds}
12216 Likewise, when the build or substitution process lasts for more than
12217 @var{seconds}, terminate it and report a build failure.
12219 By default, the daemon's setting is honored (@pxref{Invoking
12220 guix-daemon, @option{--timeout}}).
12222 @c Note: This option is actually not part of %standard-build-options but
12223 @c most programs honor it.
12224 @cindex verbosity, of the command-line tools
12225 @cindex build logs, verbosity
12226 @item -v @var{level}
12227 @itemx --verbosity=@var{level}
12228 Use the given verbosity @var{level}, an integer. Choosing 0 means that
12229 no output is produced, 1 is for quiet output; 2 is similar to 1 but it
12230 additionally displays download URLs; 3 shows all the build log output on
12233 @item --cores=@var{n}
12235 Allow the use of up to @var{n} CPU cores for the build. The special
12236 value @code{0} means to use as many CPU cores as available.
12238 @item --max-jobs=@var{n}
12240 Allow at most @var{n} build jobs in parallel. @xref{Invoking
12241 guix-daemon, @option{--max-jobs}}, for details about this option and the
12242 equivalent @command{guix-daemon} option.
12244 @item --debug=@var{level}
12245 Produce debugging output coming from the build daemon. @var{level} must be an
12246 integer between 0 and 5; higher means more verbose output. Setting a level of
12247 4 or more may be helpful when debugging setup issues with the build daemon.
12251 Behind the scenes, @command{guix build} is essentially an interface to
12252 the @code{package-derivation} procedure of the @code{(guix packages)}
12253 module, and to the @code{build-derivations} procedure of the @code{(guix
12254 derivations)} module.
12256 In addition to options explicitly passed on the command line,
12257 @command{guix build} and other @command{guix} commands that support
12258 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
12260 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
12261 Users can define this variable to a list of command line options that
12262 will automatically be used by @command{guix build} and other
12263 @command{guix} commands that can perform builds, as in the example
12267 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
12270 These options are parsed independently, and the result is appended to
12271 the parsed command-line options.
12275 @node Package Transformation Options
12276 @subsection Package Transformation Options
12278 @cindex package variants
12279 Another set of command-line options supported by @command{guix build}
12280 and also @command{guix package} are @dfn{package transformation
12281 options}. These are options that make it possible to define @dfn{package
12282 variants}---for instance, packages built from different source code.
12283 This is a convenient way to create customized packages on the fly
12284 without having to type in the definitions of package variants
12285 (@pxref{Defining Packages}).
12287 Package transformation options are preserved across upgrades:
12288 @command{guix upgrade} attempts to apply transformation options
12289 initially used when creating the profile to the upgraded packages.
12291 The available options are listed below. Most commands support them and
12292 also support a @option{--help-transform} option that lists all the
12293 available options and a synopsis (these options are not shown in the
12294 @option{--help} output for brevity).
12298 @cindex performance, tuning code
12299 @cindex optimization, of package code
12300 @cindex tuning, of package code
12301 @cindex SIMD support
12302 @cindex tunable packages
12303 @cindex package multi-versioning
12304 @item --tune[=@var{cpu}]
12305 Use versions of the packages marked as ``tunable'' optimized for
12306 @var{cpu}. When @var{cpu} is @code{native}, or when it is omitted, tune
12307 for the CPU on which the @command{guix} command is running.
12309 Valid @var{cpu} names are those recognized by the underlying compiler,
12310 by default the GNU Compiler Collection. On x86_64 processors, this
12311 includes CPU names such as @code{nehalem}, @code{haswell}, and
12312 @code{skylake} (@pxref{x86 Options, @code{-march},, gcc, Using the GNU
12313 Compiler Collection (GCC)}).
12315 As new generations of CPUs come out, they augment the standard
12316 instruction set architecture (ISA) with additional instructions, in
12317 particular instructions for single-instruction/multiple-data (SIMD)
12318 parallel processing. For example, while Core2 and Skylake CPUs both
12319 implement the x86_64 ISA, only the latter supports AVX2 SIMD
12322 The primary gain one can expect from @option{--tune} is for programs
12323 that can make use of those SIMD capabilities @emph{and} that do not
12324 already have a mechanism to select the right optimized code at run time.
12325 Packages that have the @code{tunable?} property set are considered
12326 @dfn{tunable packages} by the @option{--tune} option; a package
12327 definition with the property set looks like this:
12331 (name "hello-simd")
12334 ;; This package may benefit from SIMD extensions so
12335 ;; mark it as "tunable".
12336 (properties '((tunable? . #t))))
12339 Other packages are not considered tunable. This allows Guix to use
12340 generic binaries in the cases where tuning for a specific CPU is
12341 unlikely to provide any gain.
12343 Tuned packages are built with @code{-march=@var{CPU}}; under the hood,
12344 the @option{-march} option is passed to the actual wrapper by a compiler
12345 wrapper. Since the build machine may not be able to run code for the
12346 target CPU micro-architecture, the test suite is not run when building a
12349 To reduce rebuilds to the minimum, tuned packages are @emph{grafted}
12350 onto packages that depend on them (@pxref{Security Updates, grafts}).
12351 Thus, using @option{--no-grafts} cancels the effect of @option{--tune}.
12353 We call this technique @dfn{package multi-versioning}: several variants
12354 of tunable packages may be built, one for each CPU variant. It is the
12355 coarse-grain counterpart of @dfn{function multi-versioning} as
12356 implemented by the GNU tool chain (@pxref{Function Multiversioning,,,
12357 gcc, Using the GNU Compiler Collection (GCC)}).
12359 @item --with-source=@var{source}
12360 @itemx --with-source=@var{package}=@var{source}
12361 @itemx --with-source=@var{package}@@@var{version}=@var{source}
12362 Use @var{source} as the source of @var{package}, and @var{version} as
12363 its version number.
12364 @var{source} must be a file name or a URL, as for @command{guix
12365 download} (@pxref{Invoking guix download}).
12367 When @var{package} is omitted,
12368 it is taken to be the package name specified on the
12369 command line that matches the base of @var{source}---e.g.,
12370 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
12371 package is @code{guile}.
12373 Likewise, when @var{version} is omitted, the version string is inferred from
12374 @var{source}; in the previous example, it is @code{2.0.10}.
12376 This option allows users to try out versions of packages other than the
12377 one provided by the distribution. The example below downloads
12378 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
12379 the @code{ed} package:
12382 guix build ed --with-source=mirror://gnu/ed/ed-1.4.tar.gz
12385 As a developer, @option{--with-source} makes it easy to test release
12386 candidates, and even to test their impact on packages that depend on
12390 guix build elogind --with-source=@dots{}/shepherd-0.9.0rc1.tar.gz
12393 @dots{} or to build from a checkout in a pristine environment:
12396 $ git clone git://git.sv.gnu.org/guix.git
12397 $ guix build guix --with-source=guix@@1.0=./guix
12400 @item --with-input=@var{package}=@var{replacement}
12401 Replace dependency on @var{package} by a dependency on
12402 @var{replacement}. @var{package} must be a package name, and
12403 @var{replacement} must be a package specification such as @code{guile}
12404 or @code{guile@@1.8}.
12406 For instance, the following command builds Guix, but replaces its
12407 dependency on the current stable version of Guile with a dependency on
12408 the legacy version of Guile, @code{guile@@2.0}:
12411 guix build --with-input=guile=guile@@2.0 guix
12414 This is a recursive, deep replacement. So in this example, both
12415 @code{guix} and its dependency @code{guile-json} (which also depends on
12416 @code{guile}) get rebuilt against @code{guile@@2.0}.
12418 This is implemented using the @code{package-input-rewriting} Scheme
12419 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
12421 @item --with-graft=@var{package}=@var{replacement}
12422 This is similar to @option{--with-input} but with an important difference:
12423 instead of rebuilding the whole dependency chain, @var{replacement} is
12424 built and then @dfn{grafted} onto the binaries that were initially
12425 referring to @var{package}. @xref{Security Updates}, for more
12426 information on grafts.
12428 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
12429 and all its dependencies, replacing references to the version of GnuTLS
12430 they currently refer to:
12433 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
12436 This has the advantage of being much faster than rebuilding everything.
12437 But there is a caveat: it works if and only if @var{package} and
12438 @var{replacement} are strictly compatible---for example, if they provide
12439 a library, the application binary interface (ABI) of those libraries
12440 must be compatible. If @var{replacement} is somehow incompatible with
12441 @var{package}, then the resulting package may be unusable. Use with
12444 @cindex debugging info, rebuilding
12445 @item --with-debug-info=@var{package}
12446 Build @var{package} in a way that preserves its debugging info and graft
12447 it onto packages that depend on it. This is useful if @var{package}
12448 does not already provide debugging info as a @code{debug} output
12449 (@pxref{Installing Debugging Files}).
12451 For example, suppose you're experiencing a crash in Inkscape and would
12452 like to see what's up in GLib, a library deep down in Inkscape's
12453 dependency graph. GLib lacks a @code{debug} output, so debugging is
12454 tough. Fortunately, you rebuild GLib with debugging info and tack it on
12458 guix install inkscape --with-debug-info=glib
12461 Only GLib needs to be recompiled so this takes a reasonable amount of
12462 time. @xref{Installing Debugging Files}, for more info.
12465 Under the hood, this option works by passing the @samp{#:strip-binaries?
12466 #f} to the build system of the package of interest (@pxref{Build
12467 Systems}). Most build systems support that option but some do not. In
12468 that case, an error is raised.
12470 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
12471 the case), debugging info will remain unavailable even when
12472 @code{#:strip-binaries?} is false.
12475 @cindex tool chain, changing the build tool chain of a package
12476 @item --with-c-toolchain=@var{package}=@var{toolchain}
12477 This option changes the compilation of @var{package} and everything that
12478 depends on it so that they get built with @var{toolchain} instead of the
12479 default GNU tool chain for C/C++.
12481 Consider this example:
12484 guix build octave-cli \
12485 --with-c-toolchain=fftw=gcc-toolchain@@10 \
12486 --with-c-toolchain=fftwf=gcc-toolchain@@10
12489 The command above builds a variant of the @code{fftw} and @code{fftwf}
12490 packages using version 10 of @code{gcc-toolchain} instead of the default
12491 tool chain, and then builds a variant of the GNU@tie{}Octave
12492 command-line interface using them. GNU@tie{}Octave itself is also built
12493 with @code{gcc-toolchain@@10}.
12495 This other example builds the Hardware Locality (@code{hwloc}) library
12496 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
12500 guix build --with-c-toolchain=hwloc=clang-toolchain \
12501 intel-mpi-benchmarks
12505 There can be application binary interface (ABI) incompatibilities among
12506 tool chains. This is particularly true of the C++ standard library and
12507 run-time support libraries such as that of OpenMP@. By rebuilding all
12508 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
12509 the risks of incompatibility but cannot entirely eliminate them. Choose
12510 @var{package} wisely.
12513 @item --with-git-url=@var{package}=@var{url}
12514 @cindex Git, using the latest commit
12515 @cindex latest commit, building
12516 Build @var{package} from the latest commit of the @code{master} branch of the
12517 Git repository at @var{url}. Git sub-modules of the repository are fetched,
12520 For example, the following command builds the NumPy Python library against the
12521 latest commit of the master branch of Python itself:
12524 guix build python-numpy \
12525 --with-git-url=python=https://github.com/python/cpython
12528 This option can also be combined with @option{--with-branch} or
12529 @option{--with-commit} (see below).
12531 @cindex continuous integration
12532 Obviously, since it uses the latest commit of the given branch, the result of
12533 such a command varies over time. Nevertheless it is a convenient way to
12534 rebuild entire software stacks against the latest commit of one or more
12535 packages. This is particularly useful in the context of continuous
12538 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
12539 consecutive accesses to the same repository. You may want to clean it up once
12540 in a while to save disk space.
12542 @item --with-branch=@var{package}=@var{branch}
12543 Build @var{package} from the latest commit of @var{branch}. If the
12544 @code{source} field of @var{package} is an origin with the @code{git-fetch}
12545 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
12546 repository URL is taken from that @code{source}. Otherwise you have to use
12547 @option{--with-git-url} to specify the URL of the Git repository.
12549 For instance, the following command builds @code{guile-sqlite3} from the
12550 latest commit of its @code{master} branch, and then builds @code{guix} (which
12551 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
12552 specific @code{guile-sqlite3} build:
12555 guix build --with-branch=guile-sqlite3=master cuirass
12558 @item --with-commit=@var{package}=@var{commit}
12559 This is similar to @option{--with-branch}, except that it builds from
12560 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
12561 Git commit SHA1 identifier, a tag, or a @command{git describe} style
12562 identifier such as @code{1.0-3-gabc123}.
12564 @item --with-patch=@var{package}=@var{file}
12565 Add @var{file} to the list of patches applied to @var{package}, where
12566 @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
12567 @var{file} must contain a patch; it is applied with the flags specified
12568 in the @code{origin} of @var{package} (@pxref{origin Reference}), which
12569 by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
12570 Comparing and Merging Files}).
12572 As an example, the command below rebuilds Coreutils with the GNU C
12573 Library (glibc) patched with the given patch:
12576 guix build coreutils --with-patch=glibc=./glibc-frob.patch
12579 In this example, glibc itself as well as everything that leads to
12580 Coreutils in the dependency graph is rebuilt.
12582 @cindex upstream, latest version
12583 @item --with-latest=@var{package}
12584 So you like living on the bleeding edge? This option is for you! It
12585 replaces occurrences of @var{package} in the dependency graph with its
12586 latest upstream version, as reported by @command{guix refresh}
12587 (@pxref{Invoking guix refresh}).
12589 It does so by determining the latest upstream release of @var{package}
12590 (if possible), downloading it, and authenticating it @emph{if} it comes
12591 with an OpenPGP signature.
12593 As an example, the command below builds Guix against the latest version
12597 guix build guix --with-latest=guile-json
12600 There are limitations. First, in cases where the tool cannot or does
12601 not know how to authenticate source code, you are at risk of running
12602 malicious code; a warning is emitted in this case. Second, this option
12603 simply changes the source used in the existing package definitions,
12604 which is not always sufficient: there might be additional dependencies
12605 that need to be added, patches to apply, and more generally the quality
12606 assurance work that Guix developers normally do will be missing.
12608 You've been warned! In all the other cases, it's a snappy way to stay
12609 on top. We encourage you to submit patches updating the actual package
12610 definitions once you have successfully tested an upgrade
12611 (@pxref{Contributing}).
12613 @cindex test suite, skipping
12614 @item --without-tests=@var{package}
12615 Build @var{package} without running its tests. This can be useful in
12616 situations where you want to skip the lengthy test suite of a
12617 intermediate package, or if a package's test suite fails in a
12618 non-deterministic fashion. It should be used with care because running
12619 the test suite is a good way to ensure a package is working as intended.
12621 Turning off tests leads to a different store item. Consequently, when
12622 using this option, anything that depends on @var{package} must be
12623 rebuilt, as in this example:
12626 guix install --without-tests=python python-notebook
12629 The command above installs @code{python-notebook} on top of
12630 @code{python} built without running its test suite. To do so, it also
12631 rebuilds everything that depends on @code{python}, including
12632 @code{python-notebook} itself.
12634 Internally, @option{--without-tests} relies on changing the
12635 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
12636 Systems}). Note that some packages use a customized @code{check} phase
12637 that does not respect a @code{#:tests? #f} setting. Therefore,
12638 @option{--without-tests} has no effect on these packages.
12642 Wondering how to achieve the same effect using Scheme code, for example
12643 in your manifest, or how to write your own package transformation?
12644 @xref{Defining Package Variants}, for an overview of the programming
12645 interfaces available.
12647 @node Additional Build Options
12648 @subsection Additional Build Options
12650 The command-line options presented below are specific to @command{guix
12657 Build quietly, without displaying the build log; this is equivalent to
12658 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
12659 (or similar) and can always be retrieved using the @option{--log-file} option.
12661 @item --file=@var{file}
12662 @itemx -f @var{file}
12663 Build the package, derivation, or other file-like object that the code within
12664 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
12666 As an example, @var{file} might contain a package definition like this
12667 (@pxref{Defining Packages}):
12670 @include package-hello.scm
12673 The @var{file} may also contain a JSON representation of one or more
12674 package definitions. Running @code{guix build -f} on @file{hello.json}
12675 with the following contents would result in building the packages
12676 @code{myhello} and @code{greeter}:
12679 @verbatiminclude package-hello.json
12682 @item --manifest=@var{manifest}
12683 @itemx -m @var{manifest}
12684 Build all packages listed in the given @var{manifest}
12685 (@pxref{profile-manifest, @option{--manifest}}).
12687 @item --expression=@var{expr}
12688 @itemx -e @var{expr}
12689 Build the package or derivation @var{expr} evaluates to.
12691 For example, @var{expr} may be @code{(@@ (gnu packages guile)
12692 guile-1.8)}, which unambiguously designates this specific variant of
12693 version 1.8 of Guile.
12695 Alternatively, @var{expr} may be a G-expression, in which case it is used
12696 as a build program passed to @code{gexp->derivation}
12697 (@pxref{G-Expressions}).
12699 Lastly, @var{expr} may refer to a zero-argument monadic procedure
12700 (@pxref{The Store Monad}). The procedure must return a derivation as a
12701 monadic value, which is then passed through @code{run-with-store}.
12705 Build the source derivations of the packages, rather than the packages
12708 For instance, @code{guix build -S gcc} returns something like
12709 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
12712 The returned source tarball is the result of applying any patches and
12713 code snippets specified in the package @code{origin} (@pxref{Defining
12716 @cindex source, verification
12717 As with other derivations, the result of building a source derivation
12718 can be verified using the @option{--check} option (@pxref{build-check}).
12719 This is useful to validate that a (potentially already built or
12720 substituted, thus cached) package source matches against its declared
12723 Note that @command{guix build -S} compiles the sources only of the
12724 specified packages. They do not include the sources of statically
12725 linked dependencies and by themselves are insufficient for reproducing
12729 Fetch and return the source of @var{package-or-derivation} and all their
12730 dependencies, recursively. This is a handy way to obtain a local copy
12731 of all the source code needed to build @var{packages}, allowing you to
12732 eventually build them even without network access. It is an extension
12733 of the @option{--source} option and can accept one of the following
12734 optional argument values:
12738 This value causes the @option{--sources} option to behave in the same way
12739 as the @option{--source} option.
12742 Build the source derivations of all packages, including any source that
12743 might be listed as @code{inputs}. This is the default value.
12746 $ guix build --sources tzdata
12747 The following derivations will be built:
12748 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
12749 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
12753 Build the source derivations of all packages, as well of all transitive
12754 inputs to the packages. This can be used e.g.@: to
12755 prefetch package source for later offline building.
12758 $ guix build --sources=transitive tzdata
12759 The following derivations will be built:
12760 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
12761 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
12762 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
12763 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
12764 /gnu/store/@dots{}-make-4.1.tar.xz.drv
12765 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
12771 @item --system=@var{system}
12772 @itemx -s @var{system}
12773 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
12774 the system type of the build host. The @command{guix build} command allows
12775 you to repeat this option several times, in which case it builds for all the
12776 specified systems; other commands ignore extraneous @option{-s} options.
12779 The @option{--system} flag is for @emph{native} compilation and must not
12780 be confused with cross-compilation. See @option{--target} below for
12781 information on cross-compilation.
12784 An example use of this is on Linux-based systems, which can emulate
12785 different personalities. For instance, passing
12786 @option{--system=i686-linux} on an @code{x86_64-linux} system or
12787 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
12788 you to build packages in a complete 32-bit environment.
12791 Building for an @code{armhf-linux} system is unconditionally enabled on
12792 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
12793 allow for this functionality, notably the ThunderX.
12796 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
12797 is enabled (@pxref{Virtualization Services,
12798 @code{qemu-binfmt-service-type}}), you can build for any system for
12799 which a QEMU @code{binfmt_misc} handler is installed.
12801 Builds for a system other than that of the machine you are using can
12802 also be offloaded to a remote machine of the right architecture.
12803 @xref{Daemon Offload Setup}, for more information on offloading.
12805 @item --target=@var{triplet}
12806 @cindex cross-compilation
12807 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
12808 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
12809 configuration triplets,, autoconf, Autoconf}).
12811 @item --list-systems
12812 List all the supported systems, that can be passed as an argument to
12815 @item --list-targets
12816 List all the supported targets, that can be passed as an argument to
12819 @anchor{build-check}
12821 @cindex determinism, checking
12822 @cindex reproducibility, checking
12823 Rebuild @var{package-or-derivation}, which are already available in the
12824 store, and raise an error if the build results are not bit-for-bit
12827 This mechanism allows you to check whether previously installed
12828 substitutes are genuine (@pxref{Substitutes}), or whether the build result
12829 of a package is deterministic. @xref{Invoking guix challenge}, for more
12830 background information and tools.
12832 When used in conjunction with @option{--keep-failed}, the differing
12833 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
12834 This makes it easy to look for differences between the two results.
12837 @cindex repairing store items
12838 @cindex corruption, recovering from
12839 Attempt to repair the specified store items, if they are corrupt, by
12840 re-downloading or rebuilding them.
12842 This operation is not atomic and thus restricted to @code{root}.
12844 @item --derivations
12846 Return the derivation paths, not the output paths, of the given
12849 @item --root=@var{file}
12850 @itemx -r @var{file}
12851 @cindex GC roots, adding
12852 @cindex garbage collector roots, adding
12853 Make @var{file} a symlink to the result, and register it as a garbage
12856 Consequently, the results of this @command{guix build} invocation are
12857 protected from garbage collection until @var{file} is removed. When
12858 that option is omitted, build results are eligible for garbage
12859 collection as soon as the build completes. @xref{Invoking guix gc}, for
12863 @cindex build logs, access
12864 Return the build log file names or URLs for the given
12865 @var{package-or-derivation}, or raise an error if build logs are
12868 This works regardless of how packages or derivations are specified. For
12869 instance, the following invocations are equivalent:
12872 guix build --log-file $(guix build -d guile)
12873 guix build --log-file $(guix build guile)
12874 guix build --log-file guile
12875 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
12878 If a log is unavailable locally, and unless @option{--no-substitutes} is
12879 passed, the command looks for a corresponding log on one of the
12880 substitute servers (as specified with @option{--substitute-urls}).
12882 So for instance, imagine you want to see the build log of GDB on
12883 @code{aarch64}, but you are actually on an @code{x86_64} machine:
12886 $ guix build --log-file gdb -s aarch64-linux
12887 https://@value{SUBSTITUTE-SERVER-1}/log/@dots{}-gdb-7.10
12890 You can freely access a huge library of build logs!
12893 @node Debugging Build Failures
12894 @subsection Debugging Build Failures
12896 @cindex build failures, debugging
12897 When defining a new package (@pxref{Defining Packages}), you will
12898 probably find yourself spending some time debugging and tweaking the
12899 build until it succeeds. To do that, you need to operate the build
12900 commands yourself in an environment as close as possible to the one the
12903 To that end, the first thing to do is to use the @option{--keep-failed}
12904 or @option{-K} option of @command{guix build}, which will keep the
12905 failed build tree in @file{/tmp} or whatever directory you specified as
12906 @env{TMPDIR} (@pxref{Common Build Options, @option{--keep-failed}}).
12908 From there on, you can @command{cd} to the failed build tree and source
12909 the @file{environment-variables} file, which contains all the
12910 environment variable definitions that were in place when the build
12911 failed. So let's say you're debugging a build failure in package
12912 @code{foo}; a typical session would look like this:
12915 $ guix build foo -K
12916 @dots{} @i{build fails}
12917 $ cd /tmp/guix-build-foo.drv-0
12918 $ source ./environment-variables
12922 Now, you can invoke commands as if you were the daemon (almost) and
12923 troubleshoot your build process.
12925 Sometimes it happens that, for example, a package's tests pass when you
12926 run them manually but they fail when the daemon runs them. This can
12927 happen because the daemon runs builds in containers where, unlike in our
12928 environment above, network access is missing, @file{/bin/sh} does not
12929 exist, etc. (@pxref{Build Environment Setup}).
12931 In such cases, you may need to run inspect the build process from within
12932 a container similar to the one the build daemon creates:
12935 $ guix build -K foo
12937 $ cd /tmp/guix-build-foo.drv-0
12938 $ guix shell --no-grafts -C -D foo strace gdb
12939 [env]# source ./environment-variables
12943 Here, @command{guix shell -C} creates a container and spawns a new
12944 shell in it (@pxref{Invoking guix shell}). The @command{strace gdb}
12945 part adds the @command{strace} and @command{gdb} commands to
12946 the container, which you may find handy while debugging. The
12947 @option{--no-grafts} option makes sure we get the exact same
12948 environment, with ungrafted packages (@pxref{Security Updates}, for more
12951 To get closer to a container like that used by the build daemon, we can
12952 remove @file{/bin/sh}:
12958 (Don't worry, this is harmless: this is all happening in the throw-away
12959 container created by @command{guix shell}.)
12961 The @command{strace} command is probably not in the search path, but we
12965 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
12968 In this way, not only you will have reproduced the environment variables
12969 the daemon uses, you will also be running the build process in a container
12970 similar to the one the daemon uses.
12973 @node Invoking guix edit
12974 @section Invoking @command{guix edit}
12976 @cindex @command{guix edit}
12977 @cindex package definition, editing
12978 So many packages, so many source files! The @command{guix edit} command
12979 facilitates the life of users and packagers by pointing their editor at
12980 the source file containing the definition of the specified packages.
12984 guix edit gcc@@4.9 vim
12988 launches the program specified in the @env{VISUAL} or in the
12989 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
12992 If you are using a Guix Git checkout (@pxref{Building from Git}), or
12993 have created your own packages on @env{GUIX_PACKAGE_PATH}
12994 (@pxref{Package Modules}), you will be able to edit the package
12995 recipes. In other cases, you will be able to examine the read-only recipes
12996 for packages currently in the store.
12998 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
12999 @option{--load-path=@var{directory}} (or in short @option{-L
13000 @var{directory}}) allows you to add @var{directory} to the front of the
13001 package module search path and so make your own packages visible.
13003 @node Invoking guix download
13004 @section Invoking @command{guix download}
13006 @cindex @command{guix download}
13007 @cindex downloading package sources
13008 When writing a package definition, developers typically need to download
13009 a source tarball, compute its SHA256 hash, and write that
13010 hash in the package definition (@pxref{Defining Packages}). The
13011 @command{guix download} tool helps with this task: it downloads a file
13012 from the given URI, adds it to the store, and prints both its file name
13013 in the store and its SHA256 hash.
13015 The fact that the downloaded file is added to the store saves bandwidth:
13016 when the developer eventually tries to build the newly defined package
13017 with @command{guix build}, the source tarball will not have to be
13018 downloaded again because it is already in the store. It is also a
13019 convenient way to temporarily stash files, which may be deleted
13020 eventually (@pxref{Invoking guix gc}).
13022 The @command{guix download} command supports the same URIs as used in
13023 package definitions. In particular, it supports @code{mirror://} URIs.
13024 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
13025 Guile bindings for GnuTLS are available in the user's environment; when
13026 they are not available, an error is raised. @xref{Guile Preparations,
13027 how to install the GnuTLS bindings for Guile,, gnutls-guile,
13028 GnuTLS-Guile}, for more information.
13030 @command{guix download} verifies HTTPS server certificates by loading
13031 the certificates of X.509 authorities from the directory pointed to by
13032 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
13033 Certificates}), unless @option{--no-check-certificate} is used.
13035 The following options are available:
13038 @item --hash=@var{algorithm}
13039 @itemx -H @var{algorithm}
13040 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
13041 hash}, for more information.
13043 @item --format=@var{fmt}
13044 @itemx -f @var{fmt}
13045 Write the hash in the format specified by @var{fmt}. For more
13046 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
13048 @item --no-check-certificate
13049 Do not validate the X.509 certificates of HTTPS servers.
13051 When using this option, you have @emph{absolutely no guarantee} that you
13052 are communicating with the authentic server responsible for the given
13053 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
13055 @item --output=@var{file}
13056 @itemx -o @var{file}
13057 Save the downloaded file to @var{file} instead of adding it to the
13061 @node Invoking guix hash
13062 @section Invoking @command{guix hash}
13064 @cindex @command{guix hash}
13065 The @command{guix hash} command computes the hash of a file.
13066 It is primarily a convenience tool for anyone contributing to the
13067 distribution: it computes the cryptographic hash of one or more files, which can be
13068 used in the definition of a package (@pxref{Defining Packages}).
13070 The general syntax is:
13073 guix hash @var{option} @var{file} ...
13076 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
13077 hash of data read from standard input. @command{guix hash} has the
13082 @item --hash=@var{algorithm}
13083 @itemx -H @var{algorithm}
13084 Compute a hash using the specified @var{algorithm}, @code{sha256} by
13087 @var{algorithm} must be the name of a cryptographic hash algorithm
13088 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
13089 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
13090 Reference Manual}).
13092 @item --format=@var{fmt}
13093 @itemx -f @var{fmt}
13094 Write the hash in the format specified by @var{fmt}.
13096 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
13097 (@code{hex} and @code{hexadecimal} can be used as well).
13099 If the @option{--format} option is not specified, @command{guix hash}
13100 will output the hash in @code{nix-base32}. This representation is used
13101 in the definitions of packages.
13105 The @option{--recursive} option is deprecated in favor of
13106 @option{--serializer=nar} (see below); @option{-r} remains accepted as a
13107 convenient shorthand.
13109 @item --serializer=@var{type}
13110 @itemx -S @var{type}
13111 Compute the hash on @var{file} using @var{type} serialization.
13113 @var{type} may be one of the following:
13117 This is the default: it computes the hash of a file's contents.
13120 Compute the hash of a ``normalized archive'' (or ``nar'') containing
13121 @var{file}, including its children if it is a directory. Some of the
13122 metadata of @var{file} is part of the archive; for instance, when
13123 @var{file} is a regular file, the hash is different depending on whether
13124 @var{file} is executable or not. Metadata such as time stamps have no
13125 impact on the hash (@pxref{Invoking guix archive}, for more info on the
13127 @c FIXME: Replace xref above with xref to an ``Archive'' section when
13131 Compute the hash of the file or directory as a Git ``tree'', following
13132 the same method as the Git version control system.
13135 @item --exclude-vcs
13137 When combined with @option{--recursive}, exclude version control system
13138 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
13141 As an example, here is how you would compute the hash of a Git checkout,
13142 which is useful when using the @code{git-fetch} method (@pxref{origin
13146 $ git clone http://example.org/foo.git
13148 $ guix hash -x --serializer=nar .
13152 @node Invoking guix import
13153 @section Invoking @command{guix import}
13155 @cindex importing packages
13156 @cindex package import
13157 @cindex package conversion
13158 @cindex Invoking @command{guix import}
13159 The @command{guix import} command is useful for people who would like to
13160 add a package to the distribution with as little work as
13161 possible---a legitimate demand. The command knows of a few
13162 repositories from which it can ``import'' package metadata. The result
13163 is a package definition, or a template thereof, in the format we know
13164 (@pxref{Defining Packages}).
13166 The general syntax is:
13169 guix import @var{importer} @var{options}@dots{}
13172 @var{importer} specifies the source from which to import package
13173 metadata, and @var{options} specifies a package identifier and other
13174 options specific to @var{importer}.
13176 Some of the importers rely on the ability to run the @command{gpgv} command.
13177 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
13180 Currently, the available ``importers'' are:
13184 Import metadata for the given GNU package. This provides a template
13185 for the latest version of that GNU package, including the hash of its
13186 source tarball, and its canonical synopsis and description.
13188 Additional information such as the package dependencies and its
13189 license needs to be figured out manually.
13191 For example, the following command returns a package definition for
13195 guix import gnu hello
13198 Specific command-line options are:
13201 @item --key-download=@var{policy}
13202 As for @command{guix refresh}, specify the policy to handle missing
13203 OpenPGP keys when verifying the package signature. @xref{Invoking guix
13204 refresh, @option{--key-download}}.
13209 Import metadata from the @uref{https://pypi.python.org/, Python Package
13210 Index}. Information is taken from the JSON-formatted description
13211 available at @code{pypi.python.org} and usually includes all the relevant
13212 information, including package dependencies. For maximum efficiency, it
13213 is recommended to install the @command{unzip} utility, so that the
13214 importer can unzip Python wheels and gather data from them.
13216 The command below imports metadata for the latest version of the
13217 @code{itsdangerous} Python package:
13220 guix import pypi itsdangerous
13223 You can also ask for a specific version:
13226 guix import pypi itsdangerous@@1.1.0
13232 Traverse the dependency graph of the given upstream package recursively
13233 and generate package expressions for all those packages that are not yet
13239 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
13240 is taken from the JSON-formatted description available at
13241 @code{rubygems.org} and includes most relevant information, including
13242 runtime dependencies. There are some caveats, however. The metadata
13243 doesn't distinguish between synopses and descriptions, so the same string
13244 is used for both fields. Additionally, the details of non-Ruby
13245 dependencies required to build native extensions is unavailable and left
13246 as an exercise to the packager.
13248 The command below imports metadata for the @code{rails} Ruby package:
13251 guix import gem rails
13254 You can also ask for a specific version:
13257 guix import gem rails@@7.0.4
13263 Traverse the dependency graph of the given upstream package recursively
13264 and generate package expressions for all those packages that are not yet
13271 Import metadata from @uref{https://content.minetest.net, ContentDB}.
13272 Information is taken from the JSON-formatted metadata provided through
13273 @uref{https://content.minetest.net/help/api/, ContentDB's API} and
13274 includes most relevant information, including dependencies. There are
13275 some caveats, however. The license information is often incomplete.
13276 The commit hash is sometimes missing. The descriptions are in the
13277 Markdown format, but Guix uses Texinfo instead. Texture packs and
13278 subgames are unsupported.
13280 The command below imports metadata for the Mesecons mod by Jeija:
13283 guix import minetest Jeija/mesecons
13286 The author name can also be left out:
13289 guix import minetest mesecons
13295 Traverse the dependency graph of the given upstream package recursively
13296 and generate package expressions for all those packages that are not yet
13302 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
13303 Information is taken from the JSON-formatted metadata provided through
13304 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
13305 relevant information, such as module dependencies. License information
13306 should be checked closely. If Perl is available in the store, then the
13307 @code{corelist} utility will be used to filter core modules out of the
13308 list of dependencies.
13310 The command command below imports metadata for the Acme::Boolean Perl
13314 guix import cpan Acme::Boolean
13319 @cindex Bioconductor
13320 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
13321 central repository for the @uref{https://r-project.org, GNU@tie{}R
13322 statistical and graphical environment}.
13324 Information is extracted from the @file{DESCRIPTION} file of the package.
13326 The command command below imports metadata for the Cairo R package:
13329 guix import cran Cairo
13332 You can also ask for a specific version:
13335 guix import cran rasterVis@@0.50.3
13338 When @option{--recursive} is added, the importer will traverse the
13339 dependency graph of the given upstream package recursively and generate
13340 package expressions for all those packages that are not yet in Guix.
13342 When @option{--style=specification} is added, the importer will generate
13343 package definitions whose inputs are package specifications instead of
13344 references to package variables. This is useful when generated package
13345 definitions are to be appended to existing user modules, as the list of
13346 used package modules need not be changed. The default is
13347 @option{--style=variable}.
13349 When @option{--archive=bioconductor} is added, metadata is imported from
13350 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
13351 packages for the analysis and comprehension of high-throughput
13352 genomic data in bioinformatics.
13354 Information is extracted from the @file{DESCRIPTION} file contained in the
13357 The command below imports metadata for the GenomicRanges R package:
13360 guix import cran --archive=bioconductor GenomicRanges
13363 Finally, you can also import R packages that have not yet been published on
13364 CRAN or Bioconductor as long as they are in a git repository. Use
13365 @option{--archive=git} followed by the URL of the git repository:
13368 guix import cran --archive=git https://github.com/immunogenomics/harmony
13374 Import TeX package information from the TeX Live package database for
13375 TeX packages that are part of the @uref{https://www.tug.org/texlive/,
13376 TeX Live distribution}.
13378 Information about the package is obtained from the TeX Live package
13379 database, a plain text file that is included in the @code{texlive-bin}
13380 package. The source code is downloaded from possibly multiple locations
13381 in the SVN repository of the Tex Live project.
13383 The command command below imports metadata for the @code{fontspec}
13387 guix import texlive fontspec
13391 @cindex JSON, import
13392 Import package metadata from a local JSON file. Consider the following
13393 example package definition in JSON format:
13399 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
13400 "build-system": "gnu",
13401 "home-page": "https://www.gnu.org/software/hello/",
13402 "synopsis": "Hello, GNU world: An example GNU package",
13403 "description": "GNU Hello prints a greeting.",
13404 "license": "GPL-3.0+",
13405 "native-inputs": ["gettext"]
13409 The field names are the same as for the @code{<package>} record
13410 (@xref{Defining Packages}). References to other packages are provided
13411 as JSON lists of quoted package specification strings such as
13412 @code{guile} or @code{guile@@2.0}.
13414 The importer also supports a more explicit source definition using the
13415 common fields for @code{<origin>} records:
13421 "method": "url-fetch",
13422 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
13424 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
13431 The command below reads metadata from the JSON file @code{hello.json}
13432 and outputs a package expression:
13435 guix import json hello.json
13440 Import metadata from the Haskell community's central package archive
13441 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
13442 Cabal files and includes all the relevant information, including package
13445 Specific command-line options are:
13450 Read a Cabal file from standard input.
13451 @item --no-test-dependencies
13453 Do not include dependencies required only by the test suites.
13454 @item --cabal-environment=@var{alist}
13455 @itemx -e @var{alist}
13456 @var{alist} is a Scheme alist defining the environment in which the
13457 Cabal conditionals are evaluated. The accepted keys are: @code{os},
13458 @code{arch}, @code{impl} and a string representing the name of a flag.
13459 The value associated with a flag has to be either the symbol
13460 @code{true} or @code{false}. The value associated with other keys
13461 has to conform to the Cabal file format definition. The default value
13462 associated with the keys @code{os}, @code{arch} and @code{impl} is
13463 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
13466 Traverse the dependency graph of the given upstream package recursively
13467 and generate package expressions for all those packages that are not yet
13471 The command below imports metadata for the latest version of the
13472 HTTP Haskell package without including test dependencies and
13473 specifying the value of the flag @samp{network-uri} as @code{false}:
13476 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
13479 A specific package version may optionally be specified by following the
13480 package name by an at-sign and a version number as in the following example:
13483 guix import hackage mtl@@2.1.3.1
13488 The @code{stackage} importer is a wrapper around the @code{hackage} one.
13489 It takes a package name, looks up the package version included in a
13490 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
13491 release and uses the @code{hackage} importer to retrieve its metadata.
13492 Note that it is up to you to select an LTS release compatible with the
13493 GHC compiler used by Guix.
13495 Specific command-line options are:
13498 @item --no-test-dependencies
13500 Do not include dependencies required only by the test suites.
13501 @item --lts-version=@var{version}
13502 @itemx -l @var{version}
13503 @var{version} is the desired LTS release version. If omitted the latest
13507 Traverse the dependency graph of the given upstream package recursively
13508 and generate package expressions for all those packages that are not yet
13512 The command below imports metadata for the HTTP Haskell package
13513 included in the LTS Stackage release version 7.18:
13516 guix import stackage --lts-version=7.18 HTTP
13521 Import metadata from an Emacs Lisp Package Archive (ELPA) package
13522 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
13524 Specific command-line options are:
13527 @item --archive=@var{repo}
13528 @itemx -a @var{repo}
13529 @var{repo} identifies the archive repository from which to retrieve the
13530 information. Currently the supported repositories and their identifiers
13534 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
13535 identifier. This is the default.
13537 Packages from @code{elpa.gnu.org} are signed with one of the keys
13538 contained in the GnuPG keyring at
13539 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
13540 @code{emacs} package (@pxref{Package Installation, ELPA package
13541 signatures,, emacs, The GNU Emacs Manual}).
13544 @uref{https://elpa.nongnu.org/nongnu/, NonGNU}, selected by the
13545 @code{nongnu} identifier.
13548 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
13549 @code{melpa-stable} identifier.
13552 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
13558 Traverse the dependency graph of the given upstream package recursively
13559 and generate package expressions for all those packages that are not yet
13565 Import metadata from the crates.io Rust package repository
13566 @uref{https://crates.io, crates.io}, as in this example:
13569 guix import crate blake2-rfc
13572 The crate importer also allows you to specify a version string:
13575 guix import crate constant-time-eq@@0.1.0
13578 Additional options include:
13583 Traverse the dependency graph of the given upstream package recursively
13584 and generate package expressions for all those packages that are not yet
13590 Import metadata from the Elm package repository
13591 @uref{https://package.elm-lang.org, package.elm-lang.org}, as in this example:
13594 guix import elm elm-explorations/webgl
13597 The Elm importer also allows you to specify a version string:
13600 guix import elm elm-explorations/webgl@@1.1.3
13603 Additional options include:
13608 Traverse the dependency graph of the given upstream package recursively
13609 and generate package expressions for all those packages that are not yet
13616 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
13617 repository used by the OCaml community.
13619 Additional options include:
13624 Traverse the dependency graph of the given upstream package recursively
13625 and generate package expressions for all those packages that are not yet
13628 By default, packages are searched in the official OPAM repository. This
13629 option, which can be used more than once, lets you add other repositories
13630 which will be searched for packages. It accepts as valid arguments:
13633 @item the name of a known repository - can be one of @code{opam},
13634 @code{coq} (equivalent to @code{coq-released}),
13635 @code{coq-core-dev}, @code{coq-extra-dev} or @code{grew}.
13636 @item the URL of a repository as expected by the
13637 @code{opam repository add} command (for instance, the URL equivalent
13638 of the above @code{opam} name would be
13639 @uref{https://opam.ocaml.org}).
13640 @item the path to a local copy of a repository (a directory containing a
13641 @file{packages/} sub-directory).
13644 Repositories are assumed to be passed to this option by order of
13645 preference. The additional repositories will not replace the default
13646 @code{opam} repository, which is always kept as a fallback.
13648 Also, please note that versions are not compared across repositories.
13649 The first repository (from left to right) that has at least one version
13650 of a given package will prevail over any others, and the version
13651 imported will be the latest one found @emph{in this repository only}.
13657 Import metadata for a Go module using
13658 @uref{https://proxy.golang.org, proxy.golang.org}.
13661 guix import go gopkg.in/yaml.v2
13664 It is possible to use a package specification with a @code{@@VERSION}
13665 suffix to import a specific version.
13667 Additional options include:
13672 Traverse the dependency graph of the given upstream package recursively
13673 and generate package expressions for all those packages that are not yet
13675 @item --pin-versions
13676 When using this option, the importer preserves the exact versions of the
13677 Go modules dependencies instead of using their latest available
13678 versions. This can be useful when attempting to import packages that
13679 recursively depend on former versions of themselves to build. When
13680 using this mode, the symbol of the package is made by appending the
13681 version to its name, so that multiple versions of the same package can
13687 Import metadata for @uref{https://wiki.call-cc.org/eggs, CHICKEN eggs}.
13688 The information is taken from @file{PACKAGE.egg} files found in the
13689 @uref{git://code.call-cc.org/eggs-5-all, eggs-5-all} Git
13690 repository. However, it does not provide all the information that we
13691 need, there is no ``description'' field, and the licenses used are not
13692 always precise (BSD is often used instead of BSD-N).
13695 guix import egg sourcehut
13698 You can also ask for a specific version:
13701 guix import egg arrays@@1.0
13704 Additional options include:
13708 Traverse the dependency graph of the given upstream package recursively
13709 and generate package expressions for all those packages that are not yet
13715 Import metadata from the hex.pm Erlang and Elixir package repository
13716 @uref{https://hex.pm, hex.pm}, as in this example:
13719 guix import hexpm stun
13722 The importer tries to determine the build system used by the package.
13724 The hexpm importer also allows you to specify a version string:
13727 guix import hexpm cf@@0.3.0
13730 Additional options include:
13735 Traverse the dependency graph of the given upstream package recursively
13736 and generate package expressions for all those packages that are not yet
13741 The structure of the @command{guix import} code is modular. It would be
13742 useful to have more importers for other package formats, and your help
13743 is welcome here (@pxref{Contributing}).
13745 @node Invoking guix refresh
13746 @section Invoking @command{guix refresh}
13748 @cindex @command {guix refresh}
13749 The primary audience of the @command{guix refresh} command is packagers.
13750 As a user, you may be interested in the @option{--with-latest} option,
13751 which can bring you package update superpowers built upon @command{guix
13752 refresh} (@pxref{Package Transformation Options,
13753 @option{--with-latest}}). By default, @command{guix refresh} reports
13754 any packages provided by the distribution that are outdated compared to
13755 the latest upstream version, like this:
13759 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
13760 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
13763 Alternatively, one can specify packages to consider, in which case a
13764 warning is emitted for packages that lack an updater:
13767 $ guix refresh coreutils guile guile-ssh
13768 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
13769 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
13772 @command{guix refresh} browses the upstream repository of each package and determines
13773 the highest version number of the releases therein. The command
13774 knows how to update specific types of packages: GNU packages, ELPA
13775 packages, etc.---see the documentation for @option{--type} below. There
13776 are many packages, though, for which it lacks a method to determine
13777 whether a new upstream release is available. However, the mechanism is
13778 extensible, so feel free to get in touch with us to add a new method!
13783 Consider the packages specified, and all the packages upon which they depend.
13786 $ guix refresh --recursive coreutils
13787 gnu/packages/acl.scm:40:13: acl would be upgraded from 2.2.53 to 2.3.1
13788 gnu/packages/m4.scm:30:12: 1.4.18 is already the latest version of m4
13789 gnu/packages/xml.scm:68:2: warning: no updater for expat
13790 gnu/packages/multiprecision.scm:40:12: 6.1.2 is already the latest version of gmp
13796 Sometimes the upstream name differs from the package name used in Guix,
13797 and @command{guix refresh} needs a little help. Most updaters honor the
13798 @code{upstream-name} property in package definitions, which can be used
13802 (define-public network-manager
13804 (name "network-manager")
13806 (properties '((upstream-name . "NetworkManager")))))
13809 When passed @option{--update}, it modifies distribution source files to
13810 update the version numbers and source tarball hashes of those package
13811 recipes (@pxref{Defining Packages}). This is achieved by downloading
13812 each package's latest source tarball and its associated OpenPGP
13813 signature, authenticating the downloaded tarball against its signature
13814 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
13815 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
13818 key used to sign the tarball is missing from the user's keyring, an
13819 attempt is made to automatically retrieve it from a public key server;
13820 when this is successful, the key is added to the user's keyring; otherwise,
13821 @command{guix refresh} reports an error.
13823 The following options are supported:
13827 @item --expression=@var{expr}
13828 @itemx -e @var{expr}
13829 Consider the package @var{expr} evaluates to.
13831 This is useful to precisely refer to a package, as in this example:
13834 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
13837 This command lists the dependents of the ``final'' libc (essentially all
13842 Update distribution source files (package recipes) in place. This is
13843 usually run from a checkout of the Guix source tree (@pxref{Running
13844 Guix Before It Is Installed}):
13847 $ ./pre-inst-env guix refresh -s non-core -u
13850 @xref{Defining Packages}, for more information on package definitions.
13852 @item --select=[@var{subset}]
13853 @itemx -s @var{subset}
13854 Select all the packages in @var{subset}, one of @code{core} or
13857 The @code{core} subset refers to all the packages at the core of the
13858 distribution---i.e., packages that are used to build ``everything
13859 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
13860 changing one of these packages in the distribution entails a rebuild of
13861 all the others. Thus, such updates are an inconvenience to users in
13862 terms of build time or bandwidth used to achieve the upgrade.
13864 The @code{non-core} subset refers to the remaining packages. It is
13865 typically useful in cases where an update of the core packages would be
13868 @item --manifest=@var{file}
13869 @itemx -m @var{file}
13870 Select all the packages from the manifest in @var{file}. This is useful to
13871 check if any packages of the user manifest can be updated.
13873 @item --type=@var{updater}
13874 @itemx -t @var{updater}
13875 Select only packages handled by @var{updater} (may be a comma-separated
13876 list of updaters). Currently, @var{updater} may be one of:
13880 the updater for GNU packages;
13882 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
13884 the updater for packages hosted at @uref{https://sourceforge.net, SourceForge};
13886 the updater for GNOME packages;
13888 the updater for KDE packages;
13890 the updater for X.org packages;
13892 the updater for packages hosted on kernel.org;
13894 the updater for @uref{https://wiki.call-cc.org/eggs/, Egg} packages;
13896 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
13898 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
13900 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
13902 the updater for @uref{https://www.cpan.org/, CPAN} packages;
13904 the updater for @uref{https://pypi.python.org, PyPI} packages.
13906 the updater for @uref{https://rubygems.org, RubyGems} packages.
13908 the updater for @uref{https://github.com, GitHub} packages.
13910 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
13912 the updater for @uref{https://www.stackage.org, Stackage} packages.
13914 the updater for @uref{https://crates.io, Crates} packages.
13916 the updater for @uref{https://launchpad.net, Launchpad} packages.
13918 a generic updater that crawls the HTML page where the source tarball of
13919 the package is hosted, when applicable.
13922 a generic updater for packages hosted on Git repositories. It tries to
13923 be smart about parsing Git tag names, but if it is not able to parse the
13924 tag name and compare tags correctly, users can define the following
13925 properties for a package.
13928 @item @code{release-tag-prefix}: a regular expression for matching a prefix of
13931 @item @code{release-tag-suffix}: a regular expression for matching a suffix of
13934 @item @code{release-tag-version-delimiter}: a string used as the delimiter in
13935 the tag name for separating the numbers of the version.
13937 @item @code{accept-pre-releases}: by default, the updater will ignore
13938 pre-releases; to make it also look for pre-releases, set the this
13939 property to @code{#t}.
13948 '((release-tag-prefix . "^release0-")
13949 (release-tag-suffix . "[a-z]?$")
13950 (release-tag-version-delimiter . ":"))))
13956 For instance, the following command only checks for updates of Emacs
13957 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
13960 $ guix refresh --type=elpa,cran
13961 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
13962 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
13965 @item --list-updaters
13966 List available updaters and exit (see @option{--type} above).
13968 For each updater, display the fraction of packages it covers; at the
13969 end, display the fraction of packages covered by all these updaters.
13972 In addition, @command{guix refresh} can be passed one or more package
13973 names, as in this example:
13976 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
13980 The command above specifically updates the @code{emacs} and
13981 @code{idutils} packages. The @option{--select} option would have no
13982 effect in this case. You might also want to update definitions that
13983 correspond to the packages installed in your profile:
13986 $ ./pre-inst-env guix refresh -u \
13987 $(guix package --list-installed | cut -f1)
13990 When considering whether to upgrade a package, it is sometimes
13991 convenient to know which packages would be affected by the upgrade and
13992 should be checked for compatibility. For this the following option may
13993 be used when passing @command{guix refresh} one or more package names:
13997 @item --list-dependent
13999 List top-level dependent packages that would need to be rebuilt as a
14000 result of upgrading one or more packages.
14002 @xref{Invoking guix graph, the @code{reverse-package} type of
14003 @command{guix graph}}, for information on how to visualize the list of
14004 dependents of a package.
14008 Be aware that the @option{--list-dependent} option only
14009 @emph{approximates} the rebuilds that would be required as a result of
14010 an upgrade. More rebuilds might be required under some circumstances.
14013 $ guix refresh --list-dependent flex
14014 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
14015 hop@@2.4.0 emacs-geiser@@0.13 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
14018 The command above lists a set of packages that could be built to check
14019 for compatibility with an upgraded @code{flex} package.
14023 @item --list-transitive
14024 List all the packages which one or more packages depend upon.
14027 $ guix refresh --list-transitive flex
14028 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
14029 bison@@3.0.5 indent@@2.2.10 tar@@1.30 gzip@@1.9 bzip2@@1.0.6 xz@@5.2.4 file@@5.33 @dots{}
14034 The command above lists a set of packages which, when changed, would cause
14035 @code{flex} to be rebuilt.
14037 The following options can be used to customize GnuPG operation:
14041 @item --gpg=@var{command}
14042 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
14043 for in @code{$PATH}.
14045 @item --keyring=@var{file}
14046 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
14047 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
14048 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
14049 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
14050 information on a tool to manipulate keybox files).
14052 When this option is omitted, @command{guix refresh} uses
14053 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
14054 signing keys. OpenPGP signatures are checked against keys from this keyring;
14055 missing keys are downloaded to this keyring as well (see
14056 @option{--key-download} below).
14058 You can export keys from your default GPG keyring into a keybox file using
14059 commands like this one:
14062 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
14065 Likewise, you can fetch keys to a specific keybox file like this:
14068 gpg --no-default-keyring --keyring mykeyring.kbx \
14069 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
14072 @xref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
14073 Privacy Guard}, for more information on GPG's @option{--keyring} option.
14075 @item --key-download=@var{policy}
14076 Handle missing OpenPGP keys according to @var{policy}, which may be one
14081 Always download missing OpenPGP keys from the key server, and add them
14082 to the user's GnuPG keyring.
14085 Never try to download missing OpenPGP keys. Instead just bail out.
14088 When a package signed with an unknown OpenPGP key is encountered, ask
14089 the user whether to download it or not. This is the default behavior.
14092 @item --key-server=@var{host}
14093 Use @var{host} as the OpenPGP key server when importing a public key.
14095 @item --load-path=@var{directory}
14096 @itemx -L @var{directory}
14097 Add @var{directory} to the front of the package module search path
14098 (@pxref{Package Modules}).
14100 This allows users to define their own packages and make them visible to
14101 the command-line tools.
14105 The @code{github} updater uses the
14106 @uref{https://developer.github.com/v3/, GitHub API} to query for new
14107 releases. When used repeatedly e.g.@: when refreshing all packages,
14108 GitHub will eventually refuse to answer any further API requests. By
14109 default 60 API requests per hour are allowed, and a full refresh on all
14110 GitHub packages in Guix requires more than this. Authentication with
14111 GitHub through the use of an API token alleviates these limits. To use
14112 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
14113 token procured from @uref{https://github.com/settings/tokens} or
14117 @node Invoking guix style
14118 @section Invoking @command{guix style}
14120 @cindex @command{guix style}
14121 @cindex styling rules
14122 @cindex lint, code style
14123 @cindex format, code style
14124 @cindex format conventions
14125 The @command{guix style} command helps users and packagers alike style
14126 their package definitions and configuration files according to the
14127 latest fashionable trends. It can either reformat whole files, with the
14128 @option{--whole-file} option, or apply specific @dfn{styling rules} to
14129 individual package definitions. The command currently provides the
14130 following styling rules:
14134 formatting package definitions according to the project's conventions
14135 (@pxref{Formatting Code});
14138 rewriting package inputs to the ``new style'', as explained below.
14141 The way package inputs are written is going through a transition
14142 (@pxref{package Reference}, for more on package inputs). Until version
14143 1.3.0, package inputs were written using the ``old style'', where each
14144 input was given an explicit label, most of the time the package name:
14149 ;; The "old style" (deprecated).
14150 (inputs `(("libunistring" ,libunistring)
14151 ("libffi" ,libffi))))
14154 Today, the old style is deprecated and the preferred style looks like
14160 ;; The "new style".
14161 (inputs (list libunistring libffi)))
14164 Likewise, uses of @code{alist-delete} and friends to manipulate inputs
14165 is now deprecated in favor of @code{modify-inputs} (@pxref{Defining
14166 Package Variants}, for more info on @code{modify-inputs}).
14168 In the vast majority of cases, this is a purely mechanical change on the
14169 surface syntax that does not even incur a package rebuild. Running
14170 @command{guix style -S inputs} can do that for you, whether you're working on
14171 packages in Guix proper or in an external channel.
14173 The general syntax is:
14176 guix style [@var{options}] @var{package}@dots{}
14179 This causes @command{guix style} to analyze and rewrite the definition
14180 of @var{package}@dots{} or, when @var{package} is omitted, of @emph{all}
14181 the packages. The @option{--styling} or @option{-S} option allows you
14182 to select the style rule, the default rule being @code{format}---see
14185 To reformat entire source files, the syntax is:
14188 guix style --whole-file @var{file}@dots{}
14191 The available options are listed below.
14196 Show source file locations that would be edited but do not modify them.
14200 Reformat the given files in their entirety. In that case, subsequent
14201 arguments are interpreted as file names (rather than package names), and
14202 the @option{--styling} option has no effect.
14204 As an example, here is how you might reformat your operating system
14205 configuration (you need write permissions for the file):
14208 guix style -f /etc/config.scm
14211 @item --styling=@var{rule}
14212 @itemx -S @var{rule}
14213 Apply @var{rule}, one of the following styling rules:
14217 Format the given package definition(s)---this is the default styling
14218 rule. For example, a packager running Guix on a checkout
14219 (@pxref{Running Guix Before It Is Installed}) might want to reformat the
14220 definition of the Coreutils package like so:
14223 ./pre-inst-env guix style coreutils
14227 Rewrite package inputs to the ``new style'', as described above. This
14228 is how you would rewrite inputs of package @code{whatnot} in your own
14232 guix style -L ~/my/channel -S inputs whatnot
14235 Rewriting is done in a conservative way: preserving comments and bailing
14236 out if it cannot make sense of the code that appears in an inputs field.
14237 The @option{--input-simplification} option described below provides
14238 fine-grain control over when inputs should be simplified.
14241 @item --list-stylings
14243 List and describe the available styling rules and exit.
14245 @item --load-path=@var{directory}
14246 @itemx -L @var{directory}
14247 Add @var{directory} to the front of the package module search path
14248 (@pxref{Package Modules}).
14250 @item --expression=@var{expr}
14251 @itemx -e @var{expr}
14252 Style the package @var{expr} evaluates to.
14254 For example, running:
14257 guix style -e '(@@ (gnu packages gcc) gcc-5)'
14260 styles the @code{gcc-5} package definition.
14262 @item --input-simplification=@var{policy}
14263 When using the @code{inputs} styling rule, with @samp{-S inputs}, this
14264 option specifies the package input simplification policy for cases where
14265 an input label does not match the corresponding package name.
14266 @var{policy} may be one of the following:
14270 Simplify inputs only when the change is ``silent'', meaning that the
14271 package does not need to be rebuilt (its derivation is unchanged).
14274 Simplify inputs only when that is ``safe'' to do: the package might need
14275 to be rebuilt, but the change is known to have no observable effect.
14278 Simplify inputs even when input labels do not match package names, and
14279 even if that might have an observable effect.
14282 The default is @code{silent}, meaning that input simplifications do not
14283 trigger any package rebuild.
14286 @node Invoking guix lint
14287 @section Invoking @command{guix lint}
14289 @cindex @command{guix lint}
14290 @cindex package, checking for errors
14291 The @command{guix lint} command is meant to help package developers avoid
14292 common errors and use a consistent style. It runs a number of checks on
14293 a given set of packages in order to find common mistakes in their
14294 definitions. Available @dfn{checkers} include (see
14295 @option{--list-checkers} for a complete list):
14300 Validate certain typographical and stylistic rules about package
14301 descriptions and synopses.
14303 @item inputs-should-be-native
14304 Identify inputs that should most likely be native inputs.
14310 @itemx source-file-name
14311 Probe @code{home-page} and @code{source} URLs and report those that are
14312 invalid. Suggest a @code{mirror://} URL when applicable. If the
14313 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
14314 URL@. Check that the source file name is meaningful, e.g.@: is not just a
14315 version number or ``git-checkout'', without a declared @code{file-name}
14316 (@pxref{origin Reference}).
14318 @item source-unstable-tarball
14319 Parse the @code{source} URL to determine if a tarball from GitHub is
14320 autogenerated or if it is a release tarball. Unfortunately GitHub's
14321 autogenerated tarballs are sometimes regenerated.
14324 Check that the derivation of the given packages can be successfully
14325 computed for all the supported systems (@pxref{Derivations}).
14327 @item profile-collisions
14328 Check whether installing the given packages in a profile would lead to
14329 collisions. Collisions occur when several packages with the same name
14330 but a different version or a different store file name are propagated.
14331 @xref{package Reference, @code{propagated-inputs}}, for more information
14332 on propagated inputs.
14335 @cindex Software Heritage, source code archive
14336 @cindex archival of source code, Software Heritage
14337 Checks whether the package's source code is archived at
14338 @uref{https://www.softwareheritage.org, Software Heritage}.
14340 When the source code that is not archived comes from a version-control system
14341 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
14342 ``save'' request so that it eventually archives it. This ensures that the
14343 source will remain available in the long term, and that Guix can fall back to
14344 Software Heritage should the source code disappear from its original host.
14345 The status of recent ``save'' requests can be
14346 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
14348 When source code is a tarball obtained with @code{url-fetch}, simply print a
14349 message when it is not archived. As of this writing, Software Heritage does
14350 not allow requests to save arbitrary tarballs; we are working on ways to
14351 ensure that non-VCS source code is also archived.
14354 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
14355 request rate per IP address}. When the limit is reached, @command{guix lint}
14356 prints a message and the @code{archival} checker stops doing anything until
14357 that limit has been reset.
14360 @cindex security vulnerabilities
14361 @cindex CVE, Common Vulnerabilities and Exposures
14362 Report known vulnerabilities found in the Common Vulnerabilities and
14363 Exposures (CVE) databases of the current and past year
14364 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
14367 To view information about a particular vulnerability, visit pages such as:
14371 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
14373 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
14377 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
14378 @code{CVE-2015-7554}.
14380 Package developers can specify in package recipes the
14381 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
14382 name and version of the package when they differ from the name or version
14383 that Guix uses, as in this example:
14389 ;; CPE calls this package "grub2".
14390 (properties '((cpe-name . "grub2")
14391 (cpe-version . "2.3"))))
14394 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
14395 Some entries in the CVE database do not specify which version of a
14396 package they apply to, and would thus ``stick around'' forever. Package
14397 developers who found CVE alerts and verified they can be ignored can
14398 declare them as in this example:
14404 ;; These CVEs no longer apply and can be safely ignored.
14405 (properties `((lint-hidden-cve . ("CVE-2011-0433"
14408 "CVE-2011-5244")))))
14412 Warn about obvious source code formatting issues: trailing white space,
14413 use of tabulations, etc.
14416 Report old-style input labels that do not match the name of the
14417 corresponding package. This aims to help migrate from the ``old input
14418 style''. @xref{package Reference}, for more information on package
14419 inputs and input styles. @xref{Invoking guix style}, on how to migrate
14423 The general syntax is:
14426 guix lint @var{options} @var{package}@dots{}
14429 If no package is given on the command line, then all packages are checked.
14430 The @var{options} may be zero or more of the following:
14433 @item --list-checkers
14435 List and describe all the available checkers that will be run on packages
14440 Only enable the checkers specified in a comma-separated list using the
14441 names returned by @option{--list-checkers}.
14445 Only disable the checkers specified in a comma-separated list using the
14446 names returned by @option{--list-checkers}.
14448 @item --expression=@var{expr}
14449 @itemx -e @var{expr}
14450 Consider the package @var{expr} evaluates to.
14452 This is useful to unambiguously designate packages, as in this example:
14455 guix lint -c archival -e '(@@ (gnu packages guile) guile-3.0)'
14460 Only enable the checkers that do not depend on Internet access.
14462 @item --load-path=@var{directory}
14463 @itemx -L @var{directory}
14464 Add @var{directory} to the front of the package module search path
14465 (@pxref{Package Modules}).
14467 This allows users to define their own packages and make them visible to
14468 the command-line tools.
14472 @node Invoking guix size
14473 @section Invoking @command{guix size}
14476 @cindex package size
14478 @cindex @command{guix size}
14479 The @command{guix size} command helps package developers profile the
14480 disk usage of packages. It is easy to overlook the impact of an
14481 additional dependency added to a package, or the impact of using a
14482 single output for a package that could easily be split (@pxref{Packages
14483 with Multiple Outputs}). Such are the typical issues that
14484 @command{guix size} can highlight.
14486 The command can be passed one or more package specifications
14487 such as @code{gcc@@4.8}
14488 or @code{guile:debug}, or a file name in the store. Consider this
14492 $ guix size coreutils
14493 store item total self
14494 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
14495 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
14496 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
14497 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
14498 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
14499 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
14500 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
14501 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
14506 The store items listed here constitute the @dfn{transitive closure} of
14507 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
14508 would be returned by:
14511 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
14514 Here the output shows three columns next to store items. The first column,
14515 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
14516 the store item---that is, its own size plus the size of all its
14517 dependencies. The next column, labeled ``self'', shows the size of the
14518 item itself. The last column shows the ratio of the size of the item
14519 itself to the space occupied by all the items listed here.
14521 In this example, we see that the closure of Coreutils weighs in at
14522 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
14523 libraries. (That libc and GCC's libraries represent a large fraction of
14524 the closure is not a problem @i{per se} because they are always available
14525 on the system anyway.)
14527 Since the command also accepts store file names, assessing the size of
14528 a build result is straightforward:
14531 guix size $(guix system build config.scm)
14534 When the package(s) passed to @command{guix size} are available in the
14535 store@footnote{More precisely, @command{guix size} looks for the
14536 @emph{ungrafted} variant of the given package(s), as returned by
14537 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
14538 for information on grafts.}, @command{guix size} queries the daemon to determine its
14539 dependencies, and measures its size in the store, similar to @command{du
14540 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
14543 When the given packages are @emph{not} in the store, @command{guix size}
14544 reports information based on the available substitutes
14545 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
14546 store items that are not even on disk, only available remotely.
14548 You can also specify several package names:
14551 $ guix size coreutils grep sed bash
14552 store item total self
14553 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
14554 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
14555 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
14556 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
14562 In this example we see that the combination of the four packages takes
14563 102.3@tie{}MiB in total, which is much less than the sum of each closure
14564 since they have a lot of dependencies in common.
14566 When looking at the profile returned by @command{guix size}, you may
14567 find yourself wondering why a given package shows up in the profile at
14568 all. To understand it, you can use @command{guix graph --path -t
14569 references} to display the shortest path between the two packages
14570 (@pxref{Invoking guix graph}).
14572 The available options are:
14576 @item --substitute-urls=@var{urls}
14577 Use substitute information from @var{urls}.
14578 @xref{client-substitute-urls, the same option for @code{guix build}}.
14580 @item --sort=@var{key}
14581 Sort lines according to @var{key}, one of the following options:
14585 the size of each item (the default);
14587 the total size of the item's closure.
14590 @item --map-file=@var{file}
14591 Write a graphical map of disk usage in PNG format to @var{file}.
14593 For the example above, the map looks like this:
14595 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
14596 produced by @command{guix size}}
14598 This option requires that
14599 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
14600 installed and visible in Guile's module search path. When that is not
14601 the case, @command{guix size} fails as it tries to load it.
14603 @item --system=@var{system}
14604 @itemx -s @var{system}
14605 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
14607 @item --load-path=@var{directory}
14608 @itemx -L @var{directory}
14609 Add @var{directory} to the front of the package module search path
14610 (@pxref{Package Modules}).
14612 This allows users to define their own packages and make them visible to
14613 the command-line tools.
14616 @node Invoking guix graph
14617 @section Invoking @command{guix graph}
14620 @cindex @command{guix graph}
14621 @cindex package dependencies
14622 Packages and their dependencies form a @dfn{graph}, specifically a
14623 directed acyclic graph (DAG). It can quickly become difficult to have a
14624 mental model of the package DAG, so the @command{guix graph} command
14625 provides a visual representation of the DAG@. By default,
14626 @command{guix graph} emits a DAG representation in the input format of
14627 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
14628 directly to the @command{dot} command of Graphviz. It can also emit an
14629 HTML page with embedded JavaScript code to display a ``chord diagram''
14630 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
14631 emit Cypher queries to construct a graph in a graph database supporting
14632 the @uref{https://www.opencypher.org/, openCypher} query language. With
14633 @option{--path}, it simply displays the shortest path between two
14634 packages. The general syntax is:
14637 guix graph @var{options} @var{package}@dots{}
14640 For example, the following command generates a PDF file representing the
14641 package DAG for the GNU@tie{}Core Utilities, showing its build-time
14645 guix graph coreutils | dot -Tpdf > dag.pdf
14648 The output looks like this:
14650 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
14652 Nice little graph, no?
14654 You may find it more pleasant to navigate the graph interactively with
14655 @command{xdot} (from the @code{xdot} package):
14658 guix graph coreutils | xdot -
14661 But there is more than one graph! The one above is concise: it is the
14662 graph of package objects, omitting implicit inputs such as GCC, libc,
14663 grep, etc. It is often useful to have such a concise graph, but
14664 sometimes one may want to see more details. @command{guix graph} supports
14665 several types of graphs, allowing you to choose the level of detail:
14669 This is the default type used in the example above. It shows the DAG of
14670 package objects, excluding implicit dependencies. It is concise, but
14671 filters out many details.
14673 @item reverse-package
14674 This shows the @emph{reverse} DAG of packages. For example:
14677 guix graph --type=reverse-package ocaml
14680 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
14681 you are also interested in cases where OCaml is an implicit dependency, see
14682 @code{reverse-bag} below).
14684 Note that for core packages this can yield huge graphs. If all you want
14685 is to know the number of packages that depend on a given package, use
14686 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
14687 @option{--list-dependent}}).
14690 This is the package DAG, @emph{including} implicit inputs.
14692 For instance, the following command:
14695 guix graph --type=bag-emerged coreutils
14698 ...@: yields this bigger graph:
14700 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
14702 At the bottom of the graph, we see all the implicit inputs of
14703 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
14705 Now, note that the dependencies of these implicit inputs---that is, the
14706 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
14707 here, for conciseness.
14710 Similar to @code{bag-emerged}, but this time including all the bootstrap
14713 @item bag-with-origins
14714 Similar to @code{bag}, but also showing origins and their dependencies.
14717 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
14718 it also takes implicit dependencies into account. For example:
14721 guix graph -t reverse-bag dune
14725 ...@: yields the graph of all packages that depend on Dune, directly or
14726 indirectly. Since Dune is an @emph{implicit} dependency of many packages
14727 @i{via} @code{dune-build-system}, this shows a large number of packages,
14728 whereas @code{reverse-package} would show very few if any.
14731 This is the most detailed representation: It shows the DAG of
14732 derivations (@pxref{Derivations}) and plain store items. Compared to
14733 the above representation, many additional nodes are visible, including
14734 build scripts, patches, Guile modules, etc.
14736 For this type of graph, it is also possible to pass a @file{.drv} file
14737 name instead of a package name, as in:
14740 guix graph -t derivation $(guix system build -d my-config.scm)
14744 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
14745 For example, the following command shows the graph for the package
14746 module that defines the @code{guile} package:
14749 guix graph -t module guile | xdot -
14753 All the types above correspond to @emph{build-time dependencies}. The
14754 following graph type represents the @emph{run-time dependencies}:
14758 This is the graph of @dfn{references} of a package output, as returned
14759 by @command{guix gc --references} (@pxref{Invoking guix gc}).
14761 If the given package output is not available in the store, @command{guix
14762 graph} attempts to obtain dependency information from substitutes.
14764 Here you can also pass a store file name instead of a package name. For
14765 example, the command below produces the reference graph of your profile
14766 (which can be big!):
14769 guix graph -t references $(readlink -f ~/.guix-profile)
14773 This is the graph of the @dfn{referrers} of a store item, as returned by
14774 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
14776 This relies exclusively on local information from your store. For
14777 instance, let us suppose that the current Inkscape is available in 10
14778 profiles on your machine; @command{guix graph -t referrers inkscape}
14779 will show a graph rooted at Inkscape and with those 10 profiles linked
14782 It can help determine what is preventing a store item from being garbage
14787 @cindex shortest path, between packages
14788 Often, the graph of the package you are interested in does not fit on
14789 your screen, and anyway all you want to know is @emph{why} that package
14790 actually depends on some seemingly unrelated package. The
14791 @option{--path} option instructs @command{guix graph} to display the
14792 shortest path between two packages (or derivations, or store items,
14796 $ guix graph --path emacs libunistring
14799 libunistring@@0.9.10
14800 $ guix graph --path -t derivation emacs libunistring
14801 /gnu/store/@dots{}-emacs-26.3.drv
14802 /gnu/store/@dots{}-mailutils-3.9.drv
14803 /gnu/store/@dots{}-libunistring-0.9.10.drv
14804 $ guix graph --path -t references emacs libunistring
14805 /gnu/store/@dots{}-emacs-26.3
14806 /gnu/store/@dots{}-libidn2-2.2.0
14807 /gnu/store/@dots{}-libunistring-0.9.10
14810 Sometimes you still want to visualize the graph but would like to trim
14811 it so it can actually be displayed. One way to do it is via the
14812 @option{--max-depth} (or @option{-M}) option, which lets you specify the
14813 maximum depth of the graph. In the example below, we visualize only
14814 @code{libreoffice} and the nodes whose distance to @code{libreoffice} is
14818 guix graph -M 2 libreoffice | xdot -f fdp -
14821 Mind you, that's still a big ball of spaghetti, but at least
14822 @command{dot} can render it quickly and it can be browsed somewhat.
14824 The available options are the following:
14827 @item --type=@var{type}
14828 @itemx -t @var{type}
14829 Produce a graph output of @var{type}, where @var{type} must be one of
14830 the values listed above.
14833 List the supported graph types.
14835 @item --backend=@var{backend}
14836 @itemx -b @var{backend}
14837 Produce a graph using the selected @var{backend}.
14839 @item --list-backends
14840 List the supported graph backends.
14842 Currently, the available backends are Graphviz and d3.js.
14845 Display the shortest path between two nodes of the type specified by
14846 @option{--type}. The example below shows the shortest path between
14847 @code{libreoffice} and @code{llvm} according to the references of
14848 @code{libreoffice}:
14851 $ guix graph --path -t references libreoffice llvm
14852 /gnu/store/@dots{}-libreoffice-6.4.2.2
14853 /gnu/store/@dots{}-libepoxy-1.5.4
14854 /gnu/store/@dots{}-mesa-19.3.4
14855 /gnu/store/@dots{}-llvm-9.0.1
14858 @item --expression=@var{expr}
14859 @itemx -e @var{expr}
14860 Consider the package @var{expr} evaluates to.
14862 This is useful to precisely refer to a package, as in this example:
14865 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
14868 @item --system=@var{system}
14869 @itemx -s @var{system}
14870 Display the graph for @var{system}---e.g., @code{i686-linux}.
14872 The package dependency graph is largely architecture-independent, but there
14873 are some architecture-dependent bits that this option allows you to visualize.
14875 @item --load-path=@var{directory}
14876 @itemx -L @var{directory}
14877 Add @var{directory} to the front of the package module search path
14878 (@pxref{Package Modules}).
14880 This allows users to define their own packages and make them visible to
14881 the command-line tools.
14884 On top of that, @command{guix graph} supports all the usual package
14885 transformation options (@pxref{Package Transformation Options}). This
14886 makes it easy to view the effect of a graph-rewriting transformation
14887 such as @option{--with-input}. For example, the command below outputs
14888 the graph of @code{git} once @code{openssl} has been replaced by
14889 @code{libressl} everywhere in the graph:
14892 guix graph git --with-input=openssl=libressl
14895 So many possibilities, so much fun!
14897 @node Invoking guix publish
14898 @section Invoking @command{guix publish}
14900 @cindex @command{guix publish}
14901 The purpose of @command{guix publish} is to enable users to easily share
14902 their store with others, who can then use it as a substitute server
14903 (@pxref{Substitutes}).
14905 When @command{guix publish} runs, it spawns an HTTP server which allows
14906 anyone with network access to obtain substitutes from it. This means
14907 that any machine running Guix can also act as if it were a build farm,
14908 since the HTTP interface is compatible with Cuirass, the software behind
14909 the @code{@value{SUBSTITUTE-SERVER-1}} build farm.
14911 For security, each substitute is signed, allowing recipients to check
14912 their authenticity and integrity (@pxref{Substitutes}). Because
14913 @command{guix publish} uses the signing key of the system, which is only
14914 readable by the system administrator, it must be started as root; the
14915 @option{--user} option makes it drop root privileges early on.
14917 The signing key pair must be generated before @command{guix publish} is
14918 launched, using @command{guix archive --generate-key} (@pxref{Invoking
14921 When the @option{--advertise} option is passed, the server advertises
14922 its availability on the local network using multicast DNS (mDNS) and DNS
14923 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
14924 guile-avahi, Using Avahi in Guile Scheme Programs}).
14926 The general syntax is:
14929 guix publish @var{options}@dots{}
14932 Running @command{guix publish} without any additional arguments will
14933 spawn an HTTP server on port 8080:
14939 @cindex socket activation, for @command{guix publish}
14940 @command{guix publish} can also be started following the systemd
14941 ``socket activation'' protocol (@pxref{Service De- and Constructors,
14942 @code{make-systemd-constructor},, shepherd, The GNU Shepherd Manual}).
14944 Once a publishing server has been authorized, the daemon may download
14945 substitutes from it. @xref{Getting Substitutes from Other Servers}.
14947 By default, @command{guix publish} compresses archives on the fly as it
14948 serves them. This ``on-the-fly'' mode is convenient in that it requires
14949 no setup and is immediately available. However, when serving lots of
14950 clients, we recommend using the @option{--cache} option, which enables
14951 caching of the archives before they are sent to clients---see below for
14952 details. The @command{guix weather} command provides a handy way to
14953 check what a server provides (@pxref{Invoking guix weather}).
14955 As a bonus, @command{guix publish} also serves as a content-addressed
14956 mirror for source files referenced in @code{origin} records
14957 (@pxref{origin Reference}). For instance, assuming @command{guix
14958 publish} is running on @code{example.org}, the following URL returns the
14959 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
14960 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
14963 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
14966 Obviously, these URLs only work for files that are in the store; in
14967 other cases, they return 404 (``Not Found'').
14969 @cindex build logs, publication
14970 Build logs are available from @code{/log} URLs like:
14973 http://example.org/log/gwspk@dots{}-guile-2.2.3
14977 When @command{guix-daemon} is configured to save compressed build logs,
14978 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
14979 URLs return the compressed log as-is, with an appropriate
14980 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
14981 running @command{guix-daemon} with @option{--log-compression=gzip} since
14982 Web browsers can automatically decompress it, which is not the case with
14985 The following options are available:
14988 @item --port=@var{port}
14989 @itemx -p @var{port}
14990 Listen for HTTP requests on @var{port}.
14992 @item --listen=@var{host}
14993 Listen on the network interface for @var{host}. The default is to
14994 accept connections from any interface.
14996 @item --user=@var{user}
14997 @itemx -u @var{user}
14998 Change privileges to @var{user} as soon as possible---i.e., once the
14999 server socket is open and the signing key has been read.
15001 @item --compression[=@var{method}[:@var{level}]]
15002 @itemx -C [@var{method}[:@var{level}]]
15003 Compress data using the given @var{method} and @var{level}. @var{method} is
15004 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
15005 omitted, @code{gzip} is used.
15007 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
15008 to different compression levels: 1 is the fastest, and 9 is the best
15009 (CPU-intensive). The default is 3.
15011 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
15012 small increase in CPU usage; see
15013 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
15014 Web page}. However, @code{lzip} achieves low decompression throughput
15015 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
15016 bottleneck for someone who downloads over a fast network connection.
15018 The compression ratio of @code{zstd} is between that of @code{lzip} and
15019 that of @code{gzip}; its main advantage is a
15020 @uref{https://facebook.github.io/zstd/,high decompression speed}.
15022 Unless @option{--cache} is used, compression occurs on the fly and
15023 the compressed streams are not
15024 cached. Thus, to reduce load on the machine that runs @command{guix
15025 publish}, it may be a good idea to choose a low compression level, to
15026 run @command{guix publish} behind a caching proxy, or to use
15027 @option{--cache}. Using @option{--cache} has the advantage that it
15028 allows @command{guix publish} to add @code{Content-Length} HTTP header
15031 This option can be repeated, in which case every substitute gets compressed
15032 using all the selected methods, and all of them are advertised. This is
15033 useful when users may not support all the compression methods: they can select
15034 the one they support.
15036 @item --cache=@var{directory}
15037 @itemx -c @var{directory}
15038 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
15039 and only serve archives that are in cache.
15041 When this option is omitted, archives and meta-data are created
15042 on-the-fly. This can reduce the available bandwidth, especially when
15043 compression is enabled, since this may become CPU-bound. Another
15044 drawback of the default mode is that the length of archives is not known
15045 in advance, so @command{guix publish} does not add a
15046 @code{Content-Length} HTTP header to its responses, which in turn
15047 prevents clients from knowing the amount of data being downloaded.
15049 Conversely, when @option{--cache} is used, the first request for a store
15050 item (@i{via} a @code{.narinfo} URL) triggers a
15051 background process to @dfn{bake} the archive---computing its
15052 @code{.narinfo} and compressing the archive, if needed. Once the
15053 archive is cached in @var{directory}, subsequent requests succeed and
15054 are served directly from the cache, which guarantees that clients get
15055 the best possible bandwidth.
15057 That first @code{.narinfo} request nonetheless returns 200, provided the
15058 requested store item is ``small enough'', below the cache bypass
15059 threshold---see @option{--cache-bypass-threshold} below. That way,
15060 clients do not have to wait until the archive is baked. For larger
15061 store items, the first @code{.narinfo} request returns 404, meaning that
15062 clients have to wait until the archive is baked.
15064 The ``baking'' process is performed by worker threads. By default, one
15065 thread per CPU core is created, but this can be customized. See
15066 @option{--workers} below.
15068 When @option{--ttl} is used, cached entries are automatically deleted
15069 when they have expired.
15071 @item --workers=@var{N}
15072 When @option{--cache} is used, request the allocation of @var{N} worker
15073 threads to ``bake'' archives.
15075 @item --ttl=@var{ttl}
15076 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
15077 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
15078 days, @code{1m} means 1 month, and so on.
15080 This allows the user's Guix to keep substitute information in cache for
15081 @var{ttl}. However, note that @code{guix publish} does not itself
15082 guarantee that the store items it provides will indeed remain available
15083 for as long as @var{ttl}.
15085 Additionally, when @option{--cache} is used, cached entries that have
15086 not been accessed for @var{ttl} and that no longer have a corresponding
15087 item in the store, may be deleted.
15089 @item --negative-ttl=@var{ttl}
15090 Similarly produce @code{Cache-Control} HTTP headers to advertise the
15091 time-to-live (TTL) of @emph{negative} lookups---missing store items, for
15092 which the HTTP 404 code is returned. By default, no negative TTL is
15095 This parameter can help adjust server load and substitute latency by
15096 instructing cooperating clients to be more or less patient when a store
15099 @item --cache-bypass-threshold=@var{size}
15100 When used in conjunction with @option{--cache}, store items smaller than
15101 @var{size} are immediately available, even when they are not yet in
15102 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
15103 for megabytes and so on. The default is @code{10M}.
15105 ``Cache bypass'' allows you to reduce the publication delay for clients
15106 at the expense of possibly additional I/O and CPU use on the server
15107 side: depending on the client access patterns, those store items can end
15108 up being baked several times until a copy is available in cache.
15110 Increasing the threshold may be useful for sites that have few users, or
15111 to guarantee that users get substitutes even for store items that are
15114 @item --nar-path=@var{path}
15115 Use @var{path} as the prefix for the URLs of ``nar'' files
15116 (@pxref{Invoking guix archive, normalized archives}).
15118 By default, nars are served at a URL such as
15119 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
15120 change the @code{/nar} part to @var{path}.
15122 @item --public-key=@var{file}
15123 @itemx --private-key=@var{file}
15124 Use the specific @var{file}s as the public/private key pair used to sign
15125 the store items being published.
15127 The files must correspond to the same key pair (the private key is used
15128 for signing and the public key is merely advertised in the signature
15129 metadata). They must contain keys in the canonical s-expression format
15130 as produced by @command{guix archive --generate-key} (@pxref{Invoking
15131 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
15132 @file{/etc/guix/signing-key.sec} are used.
15134 @item --repl[=@var{port}]
15135 @itemx -r [@var{port}]
15136 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
15137 Reference Manual}) on @var{port} (37146 by default). This is used
15138 primarily for debugging a running @command{guix publish} server.
15141 Enabling @command{guix publish} on Guix System is a one-liner: just
15142 instantiate a @code{guix-publish-service-type} service in the @code{services} field
15143 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
15144 @code{guix-publish-service-type}}).
15146 If you are instead running Guix on a ``foreign distro'', follow these
15151 If your host distro uses the systemd init system:
15154 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
15155 /etc/systemd/system/
15156 # systemctl start guix-publish && systemctl enable guix-publish
15160 If your host distro uses the Upstart init system:
15163 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
15164 # start guix-publish
15168 Otherwise, proceed similarly with your distro's init system.
15171 @node Invoking guix challenge
15172 @section Invoking @command{guix challenge}
15174 @cindex reproducible builds
15175 @cindex verifiable builds
15176 @cindex @command{guix challenge}
15178 Do the binaries provided by this server really correspond to the source
15179 code it claims to build? Is a package build process deterministic?
15180 These are the questions the @command{guix challenge} command attempts to
15183 The former is obviously an important question: Before using a substitute
15184 server (@pxref{Substitutes}), one had better @emph{verify} that it
15185 provides the right binaries, and thus @emph{challenge} it. The latter
15186 is what enables the former: If package builds are deterministic, then
15187 independent builds of the package should yield the exact same result,
15188 bit for bit; if a server provides a binary different from the one
15189 obtained locally, it may be either corrupt or malicious.
15191 We know that the hash that shows up in @file{/gnu/store} file names is
15192 the hash of all the inputs of the process that built the file or
15193 directory---compilers, libraries, build scripts,
15194 etc. (@pxref{Introduction}). Assuming deterministic build processes,
15195 one store file name should map to exactly one build output.
15196 @command{guix challenge} checks whether there is, indeed, a single
15197 mapping by comparing the build outputs of several independent builds of
15198 any given store item.
15200 The command output looks like this:
15204 --substitute-urls="https://@value{SUBSTITUTE-SERVER-1} https://guix.example.org" \
15205 openssl git pius coreutils grep
15206 updating substitutes from 'https://@value{SUBSTITUTE-SERVER-1}'... 100.0%
15207 updating substitutes from 'https://guix.example.org'... 100.0%
15208 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
15209 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
15210 https://@value{SUBSTITUTE-SERVER-1}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
15211 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
15213 /lib/libcrypto.so.1.1
15216 /gnu/store/@dots{}-git-2.5.0 contents differ:
15217 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
15218 https://@value{SUBSTITUTE-SERVER-1}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
15219 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
15221 /libexec/git-core/git-fsck
15223 /gnu/store/@dots{}-pius-2.1.1 contents differ:
15224 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
15225 https://@value{SUBSTITUTE-SERVER-1}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
15226 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
15228 /share/man/man1/pius.1.gz
15232 5 store items were analyzed:
15233 - 2 (40.0%) were identical
15234 - 3 (60.0%) differed
15235 - 0 (0.0%) were inconclusive
15239 In this example, @command{guix challenge} queries all the substitute
15240 servers for each of the fives packages specified on the command line.
15241 It then reports those store items for which the servers obtained a
15242 result different from the local build (if it exists) and/or different
15243 from one another; here, the @samp{local hash} lines indicate that a
15244 local build result was available for each of these packages and shows
15247 @cindex non-determinism, in package builds
15248 As an example, @code{guix.example.org} always gets a different answer.
15249 Conversely, @code{@value{SUBSTITUTE-SERVER-1}} agrees with local builds, except in the
15250 case of Git. This might indicate that the build process of Git is
15251 non-deterministic, meaning that its output varies as a function of
15252 various things that Guix does not fully control, in spite of building
15253 packages in isolated environments (@pxref{Features}). Most common
15254 sources of non-determinism include the addition of timestamps in build
15255 results, the inclusion of random numbers, and directory listings sorted
15256 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
15259 To find out what is wrong with this Git binary, the easiest approach is
15263 guix challenge git \
15264 --diff=diffoscope \
15265 --substitute-urls="https://@value{SUBSTITUTE-SERVER-1} https://guix.example.org"
15268 This automatically invokes @command{diffoscope}, which displays detailed
15269 information about files that differ.
15271 Alternatively, we can do something along these lines (@pxref{Invoking guix
15275 $ wget -q -O - https://@value{SUBSTITUTE-SERVER-1}/nar/lzip/@dots{}-git-2.5.0 \
15276 | lzip -d | guix archive -x /tmp/git
15277 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
15280 This command shows the difference between the files resulting from the
15281 local build, and the files resulting from the build on
15282 @code{@value{SUBSTITUTE-SERVER-1}} (@pxref{Overview, Comparing and Merging Files,,
15283 diffutils, Comparing and Merging Files}). The @command{diff} command
15284 works great for text files. When binary files differ, a better option
15285 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
15286 visualize differences for all kinds of files.
15288 Once you have done that work, you can tell whether the differences are due
15289 to a non-deterministic build process or to a malicious server. We try
15290 hard to remove sources of non-determinism in packages to make it easier
15291 to verify substitutes, but of course, this is a process that
15292 involves not just Guix, but a large part of the free software community.
15293 In the meantime, @command{guix challenge} is one tool to help address
15296 If you are writing packages for Guix, you are encouraged to check
15297 whether @code{@value{SUBSTITUTE-SERVER-1}} and other substitute servers obtain the
15298 same build result as you did with:
15301 guix challenge @var{package}
15304 The general syntax is:
15307 guix challenge @var{options} @var{argument}@dots{}
15311 where @var{argument} is a package specification such as
15312 @code{guile@@2.0} or @code{glibc:debug} or, alternatively, a store file
15313 name as returned, for example, by @command{guix build} or @command{guix
15316 When a difference is found between the hash of a locally-built item and
15317 that of a server-provided substitute, or among substitutes provided by
15318 different servers, the command displays it as in the example above and
15319 its exit code is 2 (other non-zero exit codes denote other kinds of
15322 The one option that matters is:
15326 @item --substitute-urls=@var{urls}
15327 Consider @var{urls} the whitespace-separated list of substitute source
15328 URLs to compare to.
15330 @item --diff=@var{mode}
15331 Upon mismatches, show differences according to @var{mode}, one of:
15334 @item @code{simple} (the default)
15335 Show the list of files that differ.
15337 @item @code{diffoscope}
15338 @itemx @var{command}
15339 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
15340 two directories whose contents do not match.
15342 When @var{command} is an absolute file name, run @var{command} instead
15346 Do not show further details about the differences.
15349 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
15350 downloads the store items from the given substitute servers so that it
15355 Show details about matches (identical contents) in addition to
15356 information about mismatches.
15360 @node Invoking guix copy
15361 @section Invoking @command{guix copy}
15363 @cindex @command{guix copy}
15364 @cindex copy, of store items, over SSH
15365 @cindex SSH, copy of store items
15366 @cindex sharing store items across machines
15367 @cindex transferring store items across machines
15368 The @command{guix copy} command copies items from the store of one
15369 machine to that of another machine over a secure shell (SSH)
15370 connection@footnote{This command is available only when Guile-SSH was
15371 found. @xref{Requirements}, for details.}. For example, the following
15372 command copies the @code{coreutils} package, the user's profile, and all
15373 their dependencies over to @var{host}, logged in as @var{user}:
15376 guix copy --to=@var{user}@@@var{host} \
15377 coreutils $(readlink -f ~/.guix-profile)
15380 If some of the items to be copied are already present on @var{host},
15381 they are not actually sent.
15383 The command below retrieves @code{libreoffice} and @code{gimp} from
15384 @var{host}, assuming they are available there:
15387 guix copy --from=@var{host} libreoffice gimp
15390 The SSH connection is established using the Guile-SSH client, which is
15391 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
15392 @file{~/.ssh/config}, and uses the SSH agent for authentication.
15394 The key used to sign items that are sent must be accepted by the remote
15395 machine. Likewise, the key used by the remote machine to sign items you
15396 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
15397 own daemon. @xref{Invoking guix archive}, for more information about
15398 store item authentication.
15400 The general syntax is:
15403 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
15406 You must always specify one of the following options:
15409 @item --to=@var{spec}
15410 @itemx --from=@var{spec}
15411 Specify the host to send to or receive from. @var{spec} must be an SSH
15412 spec such as @code{example.org}, @code{charlie@@example.org}, or
15413 @code{charlie@@example.org:2222}.
15416 The @var{items} can be either package names, such as @code{gimp}, or
15417 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
15419 When specifying the name of a package to send, it is first built if
15420 needed, unless @option{--dry-run} was specified. Common build options
15421 are supported (@pxref{Common Build Options}).
15424 @node Invoking guix container
15425 @section Invoking @command{guix container}
15427 @cindex @command{guix container}
15429 As of version @value{VERSION}, this tool is experimental. The interface
15430 is subject to radical change in the future.
15433 The purpose of @command{guix container} is to manipulate processes
15434 running within an isolated environment, commonly known as a
15435 ``container'', typically created by the @command{guix shell}
15436 (@pxref{Invoking guix shell}) and @command{guix system container}
15437 (@pxref{Invoking guix system}) commands.
15439 The general syntax is:
15442 guix container @var{action} @var{options}@dots{}
15445 @var{action} specifies the operation to perform with a container, and
15446 @var{options} specifies the context-specific arguments for the action.
15448 The following actions are available:
15452 Execute a command within the context of a running container.
15457 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
15460 @var{pid} specifies the process ID of the running container.
15461 @var{program} specifies an executable file name within the root file
15462 system of the container. @var{arguments} are the additional options that
15463 will be passed to @var{program}.
15465 The following command launches an interactive login shell inside a
15466 Guix system container, started by @command{guix system container}, and whose
15467 process ID is 9001:
15470 guix container exec 9001 /run/current-system/profile/bin/bash --login
15473 Note that the @var{pid} cannot be the parent process of a container. It
15474 must be PID 1 of the container or one of its child processes.
15478 @node Invoking guix weather
15479 @section Invoking @command{guix weather}
15481 @cindex @command{guix weather}
15482 Occasionally you're grumpy because substitutes are lacking and you end
15483 up building packages by yourself (@pxref{Substitutes}). The
15484 @command{guix weather} command reports on substitute availability on the
15485 specified servers so you can have an idea of whether you'll be grumpy
15486 today. It can sometimes be useful info as a user, but it is primarily
15487 useful to people running @command{guix publish} (@pxref{Invoking guix
15490 @cindex statistics, for substitutes
15491 @cindex availability of substitutes
15492 @cindex substitute availability
15493 @cindex weather, substitute availability
15494 Here's a sample run:
15497 $ guix weather --substitute-urls=https://guix.example.org
15498 computing 5,872 package derivations for x86_64-linux...
15499 looking for 6,128 store items on https://guix.example.org..
15500 updating substitutes from 'https://guix.example.org'... 100.0%
15501 https://guix.example.org
15502 43.4% substitutes available (2,658 out of 6,128)
15503 7,032.5 MiB of nars (compressed)
15504 19,824.2 MiB on disk (uncompressed)
15505 0.030 seconds per request (182.9 seconds in total)
15506 33.5 requests per second
15508 9.8% (342 out of 3,470) of the missing items are queued
15510 x86_64-linux: 518 (59.7%)
15511 i686-linux: 221 (25.5%)
15512 aarch64-linux: 128 (14.8%)
15513 build rate: 23.41 builds per hour
15514 x86_64-linux: 11.16 builds per hour
15515 i686-linux: 6.03 builds per hour
15516 aarch64-linux: 6.41 builds per hour
15519 @cindex continuous integration, statistics
15520 As you can see, it reports the fraction of all the packages for which
15521 substitutes are available on the server---regardless of whether
15522 substitutes are enabled, and regardless of whether this server's signing
15523 key is authorized. It also reports the size of the compressed archives
15524 (``nars'') provided by the server, the size the corresponding store
15525 items occupy in the store (assuming deduplication is turned off), and
15526 the server's throughput. The second part gives continuous integration
15527 (CI) statistics, if the server supports it. In addition, using the
15528 @option{--coverage} option, @command{guix weather} can list ``important''
15529 package substitutes missing on the server (see below).
15531 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
15532 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
15533 challenge}, it ignores signatures on those substitutes, which is
15534 innocuous since the command only gathers statistics and cannot install
15537 The general syntax is:
15540 guix weather @var{options}@dots{} [@var{packages}@dots{}]
15543 When @var{packages} is omitted, @command{guix weather} checks the availability
15544 of substitutes for @emph{all} the packages, or for those specified with
15545 @option{--manifest}; otherwise it only considers the specified packages. It
15546 is also possible to query specific system types with @option{--system}.
15547 @command{guix weather} exits with a non-zero code when the fraction of
15548 available substitutes is below 100%.
15550 The available options are listed below.
15553 @item --substitute-urls=@var{urls}
15554 @var{urls} is the space-separated list of substitute server URLs to
15555 query. When this option is omitted, the default set of substitute
15556 servers is queried.
15558 @item --system=@var{system}
15559 @itemx -s @var{system}
15560 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
15561 option can be repeated, in which case @command{guix weather} will query
15562 substitutes for several system types.
15564 @item --manifest=@var{file}
15565 Instead of querying substitutes for all the packages, only ask for those
15566 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
15567 with the @code{-m} option of @command{guix package} (@pxref{Invoking
15570 This option can be repeated several times, in which case the manifests
15573 @item --coverage[=@var{count}]
15574 @itemx -c [@var{count}]
15575 Report on substitute coverage for packages: list packages with at least
15576 @var{count} dependents (zero by default) for which substitutes are
15577 unavailable. Dependent packages themselves are not listed: if @var{b} depends
15578 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
15579 @var{b} usually lacks substitutes as well. The result looks like this:
15582 $ guix weather --substitute-urls=@value{SUBSTITUTE-URLS} -c 10
15583 computing 8,983 package derivations for x86_64-linux...
15584 looking for 9,343 store items on @value{SUBSTITUTE-URLS}...
15585 updating substitutes from '@value{SUBSTITUTE-URLS}'... 100.0%
15586 @value{SUBSTITUTE-URLS}
15587 64.7% substitutes available (6,047 out of 9,343)
15589 2502 packages are missing from '@value{SUBSTITUTE-URLS}' for 'x86_64-linux', among which:
15590 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
15591 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
15592 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
15596 What this example shows is that @code{kcoreaddons} and presumably the 58
15597 packages that depend on it have no substitutes at
15598 @code{@value{SUBSTITUTE-SERVER-1}}; likewise for @code{qgpgme} and the 46
15599 packages that depend on it.
15601 If you are a Guix developer, or if you are taking care of this build farm,
15602 you'll probably want to have a closer look at these packages: they may simply
15605 @item --display-missing
15606 Display the list of store items for which substitutes are missing.
15609 @node Invoking guix processes
15610 @section Invoking @command{guix processes}
15612 @cindex @command{guix processes}
15613 The @command{guix processes} command can be useful to developers and system
15614 administrators, especially on multi-user machines and on build farms: it lists
15615 the current sessions (connections to the daemon), as well as information about
15616 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
15617 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
15618 listed.}. Here's an example of the information it returns:
15621 $ sudo guix processes
15624 ClientCommand: guix shell python
15628 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
15632 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
15633 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
15634 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
15635 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
15637 ChildCommand: guix offload x86_64-linux 7200 1 28800
15639 ChildCommand: guix offload x86_64-linux 7200 1 28800
15641 ChildCommand: guix offload x86_64-linux 7200 1 28800
15644 In this example we see that @command{guix-daemon} has three clients:
15645 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
15646 integration tool; their process identifier (PID) is given by the
15647 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
15648 @command{guix-daemon} sub-process of this particular session.
15650 The @code{LockHeld} fields show which store items are currently locked
15651 by this session, which corresponds to store items being built or
15652 substituted (the @code{LockHeld} field is not displayed when
15653 @command{guix processes} is not running as root). Last, by looking at
15654 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
15655 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
15657 The output is in Recutils format so we can use the handy @command{recsel}
15658 command to select sessions of interest (@pxref{Selection Expressions,,,
15659 recutils, GNU recutils manual}). As an example, the command shows the command
15660 line and PID of the client that triggered the build of a Perl package:
15663 $ sudo guix processes | \
15664 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
15666 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
15669 Additional options are listed below.
15672 @item --format=@var{format}
15673 @itemx -f @var{format}
15674 Produce output in the specified @var{format}, one of:
15678 The default option. It outputs a set of Session recutils records
15679 that include each @code{ChildProcess} as a field.
15682 Normalize the output records into record sets (@pxref{Record Sets,,,
15683 recutils, GNU recutils manual}). Normalizing into record sets allows
15684 joins across record types. The example below lists the PID of each
15685 @code{ChildProcess} and the associated PID for @code{Session} that
15686 spawned the @code{ChildProcess} where the @code{Session} was started
15687 using @command{guix build}.
15690 $ guix processes --format=normalized | \
15694 -p Session.PID,PID \
15695 -e 'Session.ClientCommand ~ "guix build"'
15708 @node Foreign Architectures
15709 @chapter Foreign Architectures
15711 You can target computers of different CPU architectures when producing
15712 packages (@pxref{Invoking guix package}), packs (@pxref{Invoking guix
15713 pack}) or full systems (@pxref{Invoking guix system}).
15715 GNU Guix supports two distinct mechanisms to target foreign
15721 @uref{https://en.wikipedia.org/wiki/Cross_compiler,cross-compilation}
15724 The native building mechanism which consists in building using the CPU
15725 instruction set of the foreign system you are targeting. It often
15726 requires emulation, using the QEMU program for instance.
15730 * Cross-Compilation:: Cross-compiling for another architecture.
15731 * Native Builds:: Targeting another architecture through native builds.
15734 @node Cross-Compilation
15735 @section Cross-Compilation
15737 @cindex foreign architectures
15738 The commands supporting cross-compilation are proposing the
15739 @option{--list-targets} and @option{--target} options.
15741 The @option{--list-targets} option lists all the supported targets that
15742 can be passed as an argument to @option{--target}.
15745 $ guix build --list-targets
15746 The available targets are:
15748 - aarch64-linux-gnu
15749 - arm-linux-gnueabihf
15753 - mips64el-linux-gnu
15754 - powerpc-linux-gnu
15755 - powerpc64le-linux-gnu
15756 - riscv64-linux-gnu
15758 - x86_64-w64-mingw32
15761 Targets are specified as GNU triplets (@pxref{Specifying Target
15762 Triplets, GNU configuration triplets,, autoconf, Autoconf}).
15764 Those triplets are passed to GCC and the other underlying compilers
15765 possibly involved when building a package, a system image or any other
15769 $ guix build --target=aarch64-linux-gnu hello
15770 /gnu/store/9926by9qrxa91ijkhw9ndgwp4bn24g9h-hello-2.12
15772 $ file /gnu/store/9926by9qrxa91ijkhw9ndgwp4bn24g9h-hello-2.12/bin/hello
15773 /gnu/store/9926by9qrxa91ijkhw9ndgwp4bn24g9h-hello-2.12/bin/hello: ELF
15774 64-bit LSB executable, ARM aarch64 @dots{}
15777 The major benefit of cross-compilation is that there are no performance
15778 penaly compared to emulation using QEMU. There are however higher risks
15779 that some packages fail to cross-compile because few users are using
15780 this mechanism extensively.
15782 @node Native Builds
15783 @section Native Builds
15785 The commands that support impersonating a specific system have the
15786 @option{--list-systems} and @option{--system} options.
15788 The @option{--list-systems} option lists all the supported systems that
15789 can be passed as an argument to @option{--system}.
15792 $ guix build --list-systems
15793 The available systems are:
15795 - x86_64-linux [current]
15802 - powerpc64le-linux
15805 $ guix build --system=i686-linux hello
15806 /gnu/store/cc0km35s8x2z4pmwkrqqjx46i8b1i3gm-hello-2.12
15808 $ file /gnu/store/cc0km35s8x2z4pmwkrqqjx46i8b1i3gm-hello-2.12/bin/hello
15809 /gnu/store/cc0km35s8x2z4pmwkrqqjx46i8b1i3gm-hello-2.12/bin/hello: ELF
15810 32-bit LSB executable, Intel 80386 @dots{}
15813 In the above example, the current system is @var{x86_64-linux}. The
15814 @var{hello} package is however built for the @var{i686-linux} system.
15816 This is possible because the @var{i686} CPU instruction set is a subset
15817 of the @var{x86_64}, hence @var{i686} targeting binaries can be run on
15820 Still in the context of the previous example, if picking the
15821 @var{aarch64-linux} system and the @command{guix build
15822 --system=aarch64-linux hello} has to build some derivations, an extra
15823 step might be needed.
15825 The @var{aarch64-linux} targeting binaries cannot directly be run on a
15826 @var{x86_64-linux} system. An emulation layer is requested. The GNU
15827 Guix daemon can take advantage of the Linux kernel
15828 @uref{https://en.wikipedia.org/wiki/Binfmt_misc,binfmt_misc} mechanism
15829 for that. In short, the Linux kernel can defer the execution of a
15830 binary targeting a foreign platform, here @var{aarch64-linux}, to a
15831 userspace program, usually an emulator.
15833 There is a service that registers QEMU as a backend for the
15834 @code{binfmt_misc} mechanism (@pxref{Virtualization Services,
15835 @code{qemu-binfmt-service-type}}). On Debian based foreign
15836 distributions, the alternative would be the @code{qemu-user-static}
15839 If the @code{binfmt_misc} mechanism is not setup correctly, the building
15840 will fail this way:
15843 $ guix build --system=armhf-linux hello --check
15845 @ unsupported-platform /gnu/store/jjn969pijv7hff62025yxpfmc8zy0aq0-hello-2.12.drv aarch64-linux
15846 while setting up the build environment: a `aarch64-linux' is required to
15847 build `/gnu/store/jjn969pijv7hff62025yxpfmc8zy0aq0-hello-2.12.drv', but
15848 I am a `x86_64-linux'@dots{}
15851 whereas, with the @code{binfmt_misc} mechanism correctly linked with
15852 QEMU, one can expect to see:
15855 $ guix build --system=armhf-linux hello --check
15856 /gnu/store/13xz4nghg39wpymivlwghy08yzj97hlj-hello-2.12
15859 The main advantage of native building compared to cross-compiling, is
15860 that more packages are likely to build correctly. However it comes at a
15861 price: compilation backed by QEMU is @emph{way slower} than
15862 cross-compilation, because every instruction needs to be emulated.
15864 The availability of substitutes for the architecture targeted by the
15865 @code{--system} option can mitigate this problem. An other way to work
15866 around it is to install GNU Guix on a machine whose CPU supports
15867 the targeted instruction set, and set it up as an offload machine
15868 (@pxref{Daemon Offload Setup}).
15870 @node System Configuration
15871 @chapter System Configuration
15873 @cindex system configuration
15874 Guix System supports a consistent whole-system configuration
15875 mechanism. By that we mean that all aspects of the global system
15876 configuration---such as the available system services, timezone and
15877 locale settings, user accounts---are declared in a single place. Such
15878 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
15880 One of the advantages of putting all the system configuration under the
15881 control of Guix is that it supports transactional system upgrades, and
15882 makes it possible to roll back to a previous system instantiation,
15883 should something go wrong with the new one (@pxref{Features}). Another
15884 advantage is that it makes it easy to replicate the exact same configuration
15885 across different machines, or at different points in time, without
15886 having to resort to additional administration tools layered on top of
15887 the own tools of the system.
15888 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
15890 This section describes this mechanism. First we focus on the system
15891 administrator's viewpoint---explaining how the system is configured and
15892 instantiated. Then we show how this mechanism can be extended, for
15893 instance to support new system services.
15896 * Using the Configuration System:: Customizing your GNU system.
15897 * operating-system Reference:: Detail of operating-system declarations.
15898 * File Systems:: Configuring file system mounts.
15899 * Mapped Devices:: Block device extra processing.
15900 * Swap Space:: Backing RAM with disk space.
15901 * User Accounts:: Specifying user accounts.
15902 * Keyboard Layout:: How the system interprets key strokes.
15903 * Locales:: Language and cultural convention settings.
15904 * Services:: Specifying system services.
15905 * Setuid Programs:: Programs running with elevated privileges.
15906 * X.509 Certificates:: Authenticating HTTPS servers.
15907 * Name Service Switch:: Configuring libc's name service switch.
15908 * Initial RAM Disk:: Linux-Libre bootstrapping.
15909 * Bootloader Configuration:: Configuring the boot loader.
15910 * Invoking guix system:: Instantiating a system configuration.
15911 * Invoking guix deploy:: Deploying a system configuration to a remote host.
15912 * Running Guix in a VM:: How to run Guix System in a virtual machine.
15913 * Defining Services:: Adding new service definitions.
15916 @node Using the Configuration System
15917 @section Using the Configuration System
15919 The operating system is configured by providing an
15920 @code{operating-system} declaration in a file that can then be passed to
15921 the @command{guix system} command (@pxref{Invoking guix system}). A
15922 simple setup, with the default system services, the default Linux-Libre
15923 kernel, initial RAM disk, and boot loader looks like this:
15925 @findex operating-system
15927 @include os-config-bare-bones.texi
15930 This example should be self-describing. Some of the fields defined
15931 above, such as @code{host-name} and @code{bootloader}, are mandatory.
15932 Others, such as @code{packages} and @code{services}, can be omitted, in
15933 which case they get a default value.
15935 Below we discuss the effect of some of the most important fields
15936 (@pxref{operating-system Reference}, for details about all the available
15937 fields), and how to @dfn{instantiate} the operating system using
15938 @command{guix system}.
15940 @unnumberedsubsec Bootloader
15942 @cindex legacy boot, on Intel machines
15943 @cindex BIOS boot, on Intel machines
15946 The @code{bootloader} field describes the method that will be used to boot
15947 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
15948 mode, as in the example above. However, more recent machines rely instead on
15949 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
15950 the @code{bootloader} field should contain something along these lines:
15953 (bootloader-configuration
15954 (bootloader grub-efi-bootloader)
15955 (targets '("/boot/efi")))
15958 @xref{Bootloader Configuration}, for more information on the available
15959 configuration options.
15961 @unnumberedsubsec Globally-Visible Packages
15963 @vindex %base-packages
15964 The @code{packages} field lists packages that will be globally visible
15965 on the system, for all user accounts---i.e., in every user's @env{PATH}
15966 environment variable---in addition to the per-user profiles
15967 (@pxref{Invoking guix package}). The @code{%base-packages} variable
15968 provides all the tools one would expect for basic user and administrator
15969 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
15970 the @command{mg} lightweight text editor, @command{find}, @command{grep},
15971 etc. The example above adds GNU@tie{}Screen to those,
15972 taken from the @code{(gnu packages screen)}
15973 module (@pxref{Package Modules}). The
15974 @code{(list package output)} syntax can be used to add a specific output
15978 (use-modules (gnu packages))
15979 (use-modules (gnu packages dns))
15983 (packages (cons (list isc-bind "utils")
15987 @findex specification->package
15988 Referring to packages by variable name, like @code{isc-bind} above, has
15989 the advantage of being unambiguous; it also allows typos and such to be
15990 diagnosed right away as ``unbound variables''. The downside is that one
15991 needs to know which module defines which package, and to augment the
15992 @code{use-package-modules} line accordingly. To avoid that, one can use
15993 the @code{specification->package} procedure of the @code{(gnu packages)}
15994 module, which returns the best package for a given name or name and
15998 (use-modules (gnu packages))
16002 (packages (append (map specification->package
16003 '("tcpdump" "htop" "gnupg@@2.0"))
16007 @unnumberedsubsec System Services
16010 @vindex %base-services
16011 The @code{services} field lists @dfn{system services} to be made
16012 available when the system starts (@pxref{Services}).
16013 The @code{operating-system} declaration above specifies that, in
16014 addition to the basic services, we want the OpenSSH secure shell
16015 daemon listening on port 2222 (@pxref{Networking Services,
16016 @code{openssh-service-type}}). Under the hood,
16017 @code{openssh-service-type} arranges so that @command{sshd} is started with the
16018 right command-line options, possibly with supporting configuration files
16019 generated as needed (@pxref{Defining Services}).
16021 @cindex customization, of services
16022 @findex modify-services
16023 Occasionally, instead of using the base services as is, you will want to
16024 customize them. To do this, use @code{modify-services} (@pxref{Service
16025 Reference, @code{modify-services}}) to modify the list.
16027 @anchor{auto-login to TTY} For example, suppose you want to modify
16028 @code{guix-daemon} and Mingetty (the console log-in) in the
16029 @code{%base-services} list (@pxref{Base Services,
16030 @code{%base-services}}). To do that, you can write the following in
16031 your operating system declaration:
16034 (define %my-services
16035 ;; My very own list of services.
16036 (modify-services %base-services
16037 (guix-service-type config =>
16038 (guix-configuration
16040 ;; Fetch substitutes from example.org.
16042 (list "https://example.org/guix"
16043 "https://ci.guix.gnu.org"))))
16044 (mingetty-service-type config =>
16045 (mingetty-configuration
16047 ;; Automatically log in as "guest".
16048 (auto-login "guest")))))
16052 (services %my-services))
16055 This changes the configuration---i.e., the service parameters---of the
16056 @code{guix-service-type} instance, and that of all the
16057 @code{mingetty-service-type} instances in the @code{%base-services} list
16058 (@pxref{Auto-Login to a Specific TTY, see the cookbook for how to
16059 auto-login one user to a specific TTY,, guix-cookbook, GNU Guix Cookbook})).
16060 Observe how this is accomplished: first, we arrange for the original
16061 configuration to be bound to the identifier @code{config} in the
16062 @var{body}, and then we write the @var{body} so that it evaluates to the
16063 desired configuration. In particular, notice how we use @code{inherit}
16064 to create a new configuration which has the same values as the old
16065 configuration, but with a few modifications.
16067 @cindex encrypted disk
16068 The configuration for a typical ``desktop'' usage, with an encrypted
16069 root partition, a swap file on the root partition, the X11 display
16070 server, GNOME and Xfce (users can choose which of these desktop
16071 environments to use at the log-in screen by pressing @kbd{F1}), network
16072 management, power management, and more, would look like this:
16075 @include os-config-desktop.texi
16078 A graphical system with a choice of lightweight window managers
16079 instead of full-blown desktop environments would look like this:
16082 @include os-config-lightweight-desktop.texi
16085 This example refers to the @file{/boot/efi} file system by its UUID,
16086 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
16087 as returned by the @command{blkid} command.
16089 @xref{Desktop Services}, for the exact list of services provided by
16090 @code{%desktop-services}. @xref{X.509 Certificates}, for background
16091 information about the @code{nss-certs} package that is used here.
16093 Again, @code{%desktop-services} is just a list of service objects. If
16094 you want to remove services from there, you can do so using the
16095 procedures for list filtering (@pxref{SRFI-1 Filtering and
16096 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
16097 following expression returns a list that contains all the services in
16098 @code{%desktop-services} minus the Avahi service:
16101 (remove (lambda (service)
16102 (eq? (service-kind service) avahi-service-type))
16106 Alternatively, the @code{modify-services} macro can be used:
16109 (modify-services %desktop-services
16110 (delete avahi-service-type))
16114 @unnumberedsubsec Instantiating the System
16116 Assuming the @code{operating-system} declaration
16117 is stored in the @file{my-system-config.scm}
16118 file, the @command{guix system reconfigure my-system-config.scm} command
16119 instantiates that configuration, and makes it the default GRUB boot
16120 entry (@pxref{Invoking guix system}).
16123 We recommend that you keep this @file{my-system-config.scm} file safe
16124 and under version control to easily track changes to your configuration.
16127 The normal way to change the system configuration is by updating this
16128 file and re-running @command{guix system reconfigure}. One should never
16129 have to touch files in @file{/etc} or to run commands that modify the
16130 system state such as @command{useradd} or @command{grub-install}. In
16131 fact, you must avoid that since that would not only void your warranty
16132 but also prevent you from rolling back to previous versions of your
16133 system, should you ever need to.
16135 @cindex roll-back, of the operating system
16136 Speaking of roll-back, each time you run @command{guix system
16137 reconfigure}, a new @dfn{generation} of the system is created---without
16138 modifying or deleting previous generations. Old system generations get
16139 an entry in the bootloader boot menu, allowing you to boot them in case
16140 something went wrong with the latest generation. Reassuring, no? The
16141 @command{guix system list-generations} command lists the system
16142 generations available on disk. It is also possible to roll back the
16143 system via the commands @command{guix system roll-back} and
16144 @command{guix system switch-generation}.
16146 Although the @command{guix system reconfigure} command will not modify
16147 previous generations, you must take care when the current generation is not
16148 the latest (e.g., after invoking @command{guix system roll-back}), since
16149 the operation might overwrite a later generation (@pxref{Invoking guix
16152 @unnumberedsubsec The Programming Interface
16154 At the Scheme level, the bulk of an @code{operating-system} declaration
16155 is instantiated with the following monadic procedure (@pxref{The Store
16158 @deffn {Monadic Procedure} operating-system-derivation os
16159 Return a derivation that builds @var{os}, an @code{operating-system}
16160 object (@pxref{Derivations}).
16162 The output of the derivation is a single directory that refers to all
16163 the packages, configuration files, and other supporting files needed to
16164 instantiate @var{os}.
16167 This procedure is provided by the @code{(gnu system)} module. Along
16168 with @code{(gnu services)} (@pxref{Services}), this module contains the
16169 guts of Guix System. Make sure to visit it!
16172 @node operating-system Reference
16173 @section @code{operating-system} Reference
16175 This section summarizes all the options available in
16176 @code{operating-system} declarations (@pxref{Using the Configuration
16179 @deftp {Data Type} operating-system
16180 This is the data type representing an operating system configuration.
16181 By that, we mean all the global system configuration, not per-user
16182 configuration (@pxref{Using the Configuration System}).
16185 @item @code{kernel} (default: @code{linux-libre})
16186 The package object of the operating system kernel to
16187 use@footnote{Currently only the Linux-libre kernel is fully supported.
16188 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
16189 available when building a virtual machine disk image.}.
16192 @item @code{hurd} (default: @code{#f})
16193 The package object of the Hurd to be started by the kernel. When this
16194 field is set, produce a GNU/Hurd operating system. In that case,
16195 @code{kernel} must also be set to the @code{gnumach} package---the
16196 microkernel the Hurd runs on.
16199 This feature is experimental and only supported for disk images.
16202 @item @code{kernel-loadable-modules} (default: '())
16203 A list of objects (usually packages) to collect loadable kernel modules
16204 from--e.g. @code{(list ddcci-driver-linux)}.
16206 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
16207 List of strings or gexps representing additional arguments to pass on
16208 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
16210 @item @code{bootloader}
16211 The system bootloader configuration object. @xref{Bootloader Configuration}.
16214 This is the label (a string) as it appears in the bootloader's menu entry.
16215 The default label includes the kernel name and version.
16217 @item @code{keyboard-layout} (default: @code{#f})
16218 This field specifies the keyboard layout to use in the console. It can be
16219 either @code{#f}, in which case the default keyboard layout is used (usually
16220 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
16221 for more information.
16223 This keyboard layout is in effect as soon as the kernel has booted. For
16224 instance, it is the keyboard layout in effect when you type a passphrase if
16225 your root file system is on a @code{luks-device-mapping} mapped device
16226 (@pxref{Mapped Devices}).
16229 This does @emph{not} specify the keyboard layout used by the bootloader, nor
16230 that used by the graphical display server. @xref{Bootloader Configuration},
16231 for information on how to specify the bootloader's keyboard layout. @xref{X
16232 Window}, for information on how to specify the keyboard layout used by the X
16236 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
16238 @cindex initial RAM disk
16239 The list of Linux kernel modules that need to be available in the
16240 initial RAM disk. @xref{Initial RAM Disk}.
16242 @item @code{initrd} (default: @code{base-initrd})
16243 A procedure that returns an initial RAM disk for the Linux
16244 kernel. This field is provided to support low-level customization and
16245 should rarely be needed for casual use. @xref{Initial RAM Disk}.
16247 @item @code{firmware} (default: @code{%base-firmware})
16249 List of firmware packages loadable by the operating system kernel.
16251 The default includes firmware needed for Atheros- and Broadcom-based
16252 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
16253 respectively). @xref{Hardware Considerations}, for more info on
16254 supported hardware.
16256 @item @code{host-name}
16259 @item @code{hosts-file}
16261 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
16262 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
16263 Reference Manual}). The default is a file with entries for
16264 @code{localhost} and @var{host-name}.
16266 @item @code{mapped-devices} (default: @code{'()})
16267 A list of mapped devices. @xref{Mapped Devices}.
16269 @item @code{file-systems}
16270 A list of file systems. @xref{File Systems}.
16272 @item @code{swap-devices} (default: @code{'()})
16273 @cindex swap devices
16274 A list of swap spaces. @xref{Swap Space}.
16276 @item @code{users} (default: @code{%base-user-accounts})
16277 @itemx @code{groups} (default: @code{%base-groups})
16278 List of user accounts and groups. @xref{User Accounts}.
16280 If the @code{users} list lacks a user account with UID@tie{}0, a
16281 ``root'' account with UID@tie{}0 is automatically added.
16283 @item @code{skeletons} (default: @code{(default-skeletons)})
16284 A list of target file name/file-like object tuples (@pxref{G-Expressions,
16285 file-like objects}). These are the skeleton files that will be added to
16286 the home directory of newly-created user accounts.
16288 For instance, a valid value may look like this:
16291 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
16292 (".guile" ,(plain-file "guile"
16293 "(use-modules (ice-9 readline))
16294 (activate-readline)")))
16297 @item @code{issue} (default: @code{%default-issue})
16298 A string denoting the contents of the @file{/etc/issue} file, which is
16299 displayed when users log in on a text console.
16301 @item @code{packages} (default: @code{%base-packages})
16302 A list of packages to be installed in the global profile, which is accessible
16303 at @file{/run/current-system/profile}. Each element is either a package
16304 variable or a package/output tuple. Here's a simple example of both:
16307 (cons* git ; the default "out" output
16308 (list git "send-email") ; another output of git
16309 %base-packages) ; the default set
16312 The default set includes core utilities and it is good practice to
16313 install non-core utilities in user profiles (@pxref{Invoking guix
16316 @item @code{timezone}
16317 A timezone identifying string---e.g., @code{"Europe/Paris"}.
16319 You can run the @command{tzselect} command to find out which timezone
16320 string corresponds to your region. Choosing an invalid timezone name
16321 causes @command{guix system} to fail.
16323 @item @code{locale} (default: @code{"en_US.utf8"})
16324 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
16325 Library Reference Manual}). @xref{Locales}, for more information.
16327 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
16328 The list of locale definitions to be compiled and that may be used at
16329 run time. @xref{Locales}.
16331 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
16332 The list of GNU@tie{}libc packages whose locale data and tools are used
16333 to build the locale definitions. @xref{Locales}, for compatibility
16334 considerations that justify this option.
16336 @item @code{name-service-switch} (default: @code{%default-nss})
16337 Configuration of the libc name service switch (NSS)---a
16338 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
16341 @item @code{services} (default: @code{%base-services})
16342 A list of service objects denoting system services. @xref{Services}.
16344 @cindex essential services
16345 @item @code{essential-services} (default: ...)
16346 The list of ``essential services''---i.e., things like instances of
16347 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
16348 Reference}), which are derived from the operating system definition itself.
16349 As a user you should @emph{never} need to touch this field.
16351 @item @code{pam-services} (default: @code{(base-pam-services)})
16353 @cindex pluggable authentication modules
16354 Linux @dfn{pluggable authentication module} (PAM) services.
16355 @c FIXME: Add xref to PAM services section.
16357 @item @code{setuid-programs} (default: @code{%setuid-programs})
16358 List of @code{<setuid-program>}. @xref{Setuid Programs}, for more
16361 @item @code{sudoers-file} (default: @code{%sudoers-specification})
16362 @cindex sudoers file
16363 The contents of the @file{/etc/sudoers} file as a file-like object
16364 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
16366 This file specifies which users can use the @command{sudo} command, what
16367 they are allowed to do, and what privileges they may gain. The default
16368 is that only @code{root} and members of the @code{wheel} group may use
16373 @deffn {Scheme Syntax} this-operating-system
16374 When used in the @emph{lexical scope} of an operating system field definition,
16375 this identifier resolves to the operating system being defined.
16377 The example below shows how to refer to the operating system being defined in
16378 the definition of the @code{label} field:
16381 (use-modules (gnu) (guix))
16385 (label (package-full-name
16386 (operating-system-kernel this-operating-system))))
16389 It is an error to refer to @code{this-operating-system} outside an operating
16396 @section File Systems
16398 The list of file systems to be mounted is specified in the
16399 @code{file-systems} field of the operating system declaration
16400 (@pxref{Using the Configuration System}). Each file system is declared
16401 using the @code{file-system} form, like this:
16405 (mount-point "/home")
16406 (device "/dev/sda3")
16410 As usual, some of the fields are mandatory---those shown in the example
16411 above---while others can be omitted. These are described below.
16413 @deftp {Data Type} file-system
16414 Objects of this type represent file systems to be mounted. They
16415 contain the following members:
16419 This is a string specifying the type of the file system---e.g.,
16422 @item @code{mount-point}
16423 This designates the place where the file system is to be mounted.
16425 @item @code{device}
16426 This names the ``source'' of the file system. It can be one of three
16427 things: a file system label, a file system UUID, or the name of a
16428 @file{/dev} node. Labels and UUIDs offer a way to refer to file
16429 systems without having to hard-code their actual device
16430 name@footnote{Note that, while it is tempting to use
16431 @file{/dev/disk/by-uuid} and similar device names to achieve the same
16432 result, this is not recommended: These special device nodes are created
16433 by the udev daemon and may be unavailable at the time the device is
16436 @findex file-system-label
16437 File system labels are created using the @code{file-system-label}
16438 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
16439 plain strings. Here's an example of a file system referred to by its
16440 label, as shown by the @command{e2label} command:
16444 (mount-point "/home")
16446 (device (file-system-label "my-home")))
16450 UUIDs are converted from their string representation (as shown by the
16451 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
16452 @code{uuid} form expects 16-byte UUIDs as defined in
16453 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
16454 form of UUID used by the ext2 family of file systems and others, but it
16455 is different from ``UUIDs'' found in FAT file systems, for instance.},
16460 (mount-point "/home")
16462 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
16465 When the source of a file system is a mapped device (@pxref{Mapped
16466 Devices}), its @code{device} field @emph{must} refer to the mapped
16467 device name---e.g., @file{"/dev/mapper/root-partition"}.
16468 This is required so that
16469 the system knows that mounting the file system depends on having the
16470 corresponding device mapping established.
16472 @item @code{flags} (default: @code{'()})
16473 This is a list of symbols denoting mount flags. Recognized flags
16474 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
16475 access to special files), @code{no-suid} (ignore setuid and setgid
16476 bits), @code{no-atime} (do not update file access times),
16477 @code{strict-atime} (update file access time), @code{lazy-time} (only
16478 update time on the in-memory version of the file inode),
16479 @code{no-exec} (disallow program execution), and @code{shared} (make the
16481 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
16482 Manual}, for more information on these flags.
16484 @item @code{options} (default: @code{#f})
16485 This is either @code{#f}, or a string denoting mount options passed to
16486 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
16487 Library Reference Manual}, for details.
16489 Run @command{man 8 mount} for options for various file systems, but
16490 beware that what it lists as file-system-independent ``mount options'' are
16491 in fact flags, and belong in the @code{flags} field described above.
16493 The @code{file-system-options->alist} and @code{alist->file-system-options}
16494 procedures from @code{(gnu system file-systems)} can be used to convert
16495 file system options given as an association list to the string
16496 representation, and vice-versa.
16498 @item @code{mount?} (default: @code{#t})
16499 This value indicates whether to automatically mount the file system when
16500 the system is brought up. When set to @code{#f}, the file system gets
16501 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
16502 is not automatically mounted.
16504 @item @code{needed-for-boot?} (default: @code{#f})
16505 This Boolean value indicates whether the file system is needed when
16506 booting. If that is true, then the file system is mounted when the
16507 initial RAM disk (initrd) is loaded. This is always the case, for
16508 instance, for the root file system.
16510 @item @code{check?} (default: @code{#t})
16511 This Boolean indicates whether the file system should be checked for
16512 errors before being mounted. How and when this happens can be further
16513 adjusted with the following options.
16515 @item @code{skip-check-if-clean?} (default: @code{#t})
16516 When true, this Boolean indicates that a file system check triggered
16517 by @code{check?} may exit early if the file system is marked as
16518 ``clean'', meaning that it was previously correctly unmounted and
16519 should not contain errors.
16521 Setting this to false will always force a full consistency check when
16522 @code{check?} is true. This may take a very long time and is not
16523 recommended on healthy systems---in fact, it may reduce reliability!
16525 Conversely, some primitive file systems like @code{fat} do not keep
16526 track of clean shutdowns and will perform a full scan regardless of the
16527 value of this option.
16529 @item @code{repair} (default: @code{'preen})
16530 When @code{check?} finds errors, it can (try to) repair them and
16531 continue booting. This option controls when and how to do so.
16533 If false, try not to modify the file system at all. Checking certain
16534 file systems like @code{jfs} may still write to the device to replay
16535 the journal. No repairs will be attempted.
16537 If @code{#t}, try to repair any errors found and assume ``yes'' to
16538 all questions. This will fix the most errors, but may be risky.
16540 If @code{'preen}, repair only errors that are safe to fix without
16541 human interaction. What that means is left up to the developers of
16542 each file system and may be equivalent to ``none'' or ``all''.
16544 @item @code{create-mount-point?} (default: @code{#f})
16545 When true, the mount point is created if it does not exist yet.
16547 @item @code{mount-may-fail?} (default: @code{#f})
16548 When true, this indicates that mounting this file system can fail but
16549 that should not be considered an error. This is useful in unusual
16550 cases; an example of this is @code{efivarfs}, a file system that can
16551 only be mounted on EFI/UEFI systems.
16553 @item @code{dependencies} (default: @code{'()})
16554 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
16555 representing file systems that must be mounted or mapped devices that
16556 must be opened before (and unmounted or closed after) this one.
16558 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
16559 a dependency of @file{/sys/fs/cgroup/cpu} and
16560 @file{/sys/fs/cgroup/memory}.
16562 Another example is a file system that depends on a mapped device, for
16563 example for an encrypted partition (@pxref{Mapped Devices}).
16567 @deffn {Scheme Procedure} file-system-label @var{str}
16568 This procedure returns an opaque file system label from @var{str}, a
16572 (file-system-label "home")
16573 @result{} #<file-system-label "home">
16576 File system labels are used to refer to file systems by label rather
16577 than by device name. See above for examples.
16580 The @code{(gnu system file-systems)} exports the following useful
16583 @defvr {Scheme Variable} %base-file-systems
16584 These are essential file systems that are required on normal systems,
16585 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
16586 below). Operating system declarations should always contain at least
16590 @defvr {Scheme Variable} %pseudo-terminal-file-system
16591 This is the file system to be mounted as @file{/dev/pts}. It supports
16592 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
16593 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
16594 Manual}). Pseudo-terminals are used by terminal emulators such as
16598 @defvr {Scheme Variable} %shared-memory-file-system
16599 This file system is mounted as @file{/dev/shm} and is used to support
16600 memory sharing across processes (@pxref{Memory-mapped I/O,
16601 @code{shm_open},, libc, The GNU C Library Reference Manual}).
16604 @defvr {Scheme Variable} %immutable-store
16605 This file system performs a read-only ``bind mount'' of
16606 @file{/gnu/store}, making it read-only for all the users including
16607 @code{root}. This prevents against accidental modification by software
16608 running as @code{root} or by system administrators.
16610 The daemon itself is still able to write to the store: it remounts it
16611 read-write in its own ``name space.''
16614 @defvr {Scheme Variable} %binary-format-file-system
16615 The @code{binfmt_misc} file system, which allows handling of arbitrary
16616 executable file types to be delegated to user space. This requires the
16617 @code{binfmt.ko} kernel module to be loaded.
16620 @defvr {Scheme Variable} %fuse-control-file-system
16621 The @code{fusectl} file system, which allows unprivileged users to mount
16622 and unmount user-space FUSE file systems. This requires the
16623 @code{fuse.ko} kernel module to be loaded.
16626 The @code{(gnu system uuid)} module provides tools to deal with file
16627 system ``unique identifiers'' (UUIDs).
16629 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
16630 Return an opaque UUID (unique identifier) object of the given @var{type}
16631 (a symbol) by parsing @var{str} (a string):
16634 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
16635 @result{} #<<uuid> type: dce bv: @dots{}>
16637 (uuid "1234-ABCD" 'fat)
16638 @result{} #<<uuid> type: fat bv: @dots{}>
16641 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
16642 @code{ntfs}, or one of the commonly found synonyms for these.
16644 UUIDs are another way to unambiguously refer to file systems in
16645 operating system configuration. See the examples above.
16649 @node Btrfs file system
16650 @subsection Btrfs file system
16652 The Btrfs has special features, such as subvolumes, that merit being
16653 explained in more details. The following section attempts to cover
16654 basic as well as complex uses of a Btrfs file system with the Guix
16657 In its simplest usage, a Btrfs file system can be described, for
16662 (mount-point "/home")
16664 (device (file-system-label "my-home")))
16667 The example below is more complex, as it makes use of a Btrfs
16668 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
16669 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
16670 dependency on @code{mapped-devices}):
16674 (device (file-system-label "my-btrfs-pool"))
16677 (options "subvol=rootfs")
16678 (dependencies mapped-devices))
16681 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
16682 top level during the early boot, and rely on their configuration to
16683 refer to the correct subvolume path within that top level. The
16684 bootloaders operating in this way typically produce their configuration
16685 on a running system where the Btrfs partitions are already mounted and
16686 where the subvolume information is readily available. As an example,
16687 @command{grub-mkconfig}, the configuration generator command shipped
16688 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
16689 path of a subvolume.
16691 The Guix System produces a bootloader configuration using the operating
16692 system configuration as its sole input; it is therefore necessary to
16693 extract the subvolume name on which @file{/gnu/store} lives (if any)
16694 from that operating system configuration. To better illustrate,
16695 consider a subvolume named 'rootfs' which contains the root file system
16696 data. In such situation, the GRUB bootloader would only see the top
16697 level of the root Btrfs partition, e.g.:
16701 ├── rootfs (subvolume directory)
16702 ├── gnu (normal directory)
16703 ├── store (normal directory)
16707 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
16708 of the kernel, initrd binaries and any other files referred to in the
16709 GRUB configuration that must be found during the early boot.
16711 The next example shows a nested hierarchy of subvolumes and
16716 ├── rootfs (subvolume)
16717 ├── gnu (normal directory)
16718 ├── store (subvolume)
16722 This scenario would work without mounting the 'store' subvolume.
16723 Mounting 'rootfs' is sufficient, since the subvolume name matches its
16724 intended mount point in the file system hierarchy. Alternatively, the
16725 'store' subvolume could be referred to by setting the @code{subvol}
16726 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
16728 Finally, a more contrived example of nested subvolumes:
16732 ├── root-snapshots (subvolume)
16733 ├── root-current (subvolume)
16734 ├── guix-store (subvolume)
16738 Here, the 'guix-store' subvolume doesn't match its intended mount point,
16739 so it is necessary to mount it. The subvolume must be fully specified,
16740 by passing its file name to the @code{subvol} option. To illustrate,
16741 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
16742 a file system declaration such as:
16746 (device (file-system-label "btrfs-pool-1"))
16747 (mount-point "/gnu/store")
16749 (options "subvol=root-snapshots/root-current/guix-store,\
16750 compress-force=zstd,space_cache=v2"))
16753 @node Mapped Devices
16754 @section Mapped Devices
16756 @cindex device mapping
16757 @cindex mapped devices
16758 The Linux kernel has a notion of @dfn{device mapping}: a block device,
16759 such as a hard disk partition, can be @dfn{mapped} into another device,
16760 usually in @code{/dev/mapper/},
16761 with additional processing over the data that flows through
16762 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
16763 concept of a ``mapped device'' and that of a file system: both boil down
16764 to @emph{translating} input/output operations made on a file to
16765 operations on its backing store. Thus, the Hurd implements mapped
16766 devices, like file systems, using the generic @dfn{translator} mechanism
16767 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
16768 typical example is encryption device mapping: all writes to the mapped
16769 device are encrypted, and all reads are deciphered, transparently.
16770 Guix extends this notion by considering any device or set of devices that
16771 are @dfn{transformed} in some way to create a new device; for instance,
16772 RAID devices are obtained by @dfn{assembling} several other devices, such
16773 as hard disks or partitions, into a new one that behaves as one partition.
16775 Mapped devices are declared using the @code{mapped-device} form,
16776 defined as follows; for examples, see below.
16778 @deftp {Data Type} mapped-device
16779 Objects of this type represent device mappings that will be made when
16780 the system boots up.
16784 This is either a string specifying the name of the block device to be mapped,
16785 such as @code{"/dev/sda3"}, or a list of such strings when several devices
16786 need to be assembled for creating a new one. In case of LVM this is a
16787 string specifying name of the volume group to be mapped.
16790 This string specifies the name of the resulting mapped device. For
16791 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
16792 specifying @code{"my-partition"} leads to the creation of
16793 the @code{"/dev/mapper/my-partition"} device.
16794 For RAID devices of type @code{raid-device-mapping}, the full device name
16795 such as @code{"/dev/md0"} needs to be given.
16796 LVM logical volumes of type @code{lvm-device-mapping} need to
16797 be specified as @code{"VGNAME-LVNAME"}.
16800 This list of strings specifies names of the resulting mapped devices in case
16801 there are several. The format is identical to @var{target}.
16804 This must be a @code{mapped-device-kind} object, which specifies how
16805 @var{source} is mapped to @var{target}.
16809 @defvr {Scheme Variable} luks-device-mapping
16810 This defines LUKS block device encryption using the @command{cryptsetup}
16811 command from the package with the same name. It relies on the
16812 @code{dm-crypt} Linux kernel module.
16815 @defvr {Scheme Variable} raid-device-mapping
16816 This defines a RAID device, which is assembled using the @code{mdadm}
16817 command from the package with the same name. It requires a Linux kernel
16818 module for the appropriate RAID level to be loaded, such as @code{raid456}
16819 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
16822 @cindex LVM, logical volume manager
16823 @defvr {Scheme Variable} lvm-device-mapping
16824 This defines one or more logical volumes for the Linux
16825 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
16826 The volume group is activated by the @command{vgchange} command from the
16827 @code{lvm2} package.
16830 @cindex disk encryption
16832 The following example specifies a mapping from @file{/dev/sda3} to
16833 @file{/dev/mapper/home} using LUKS---the
16834 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
16835 standard mechanism for disk encryption.
16836 The @file{/dev/mapper/home}
16837 device can then be used as the @code{device} of a @code{file-system}
16838 declaration (@pxref{File Systems}).
16842 (source "/dev/sda3")
16844 (type luks-device-mapping))
16847 Alternatively, to become independent of device numbering, one may obtain
16848 the LUKS UUID (@dfn{unique identifier}) of the source device by a
16852 cryptsetup luksUUID /dev/sda3
16855 and use it as follows:
16859 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
16861 (type luks-device-mapping))
16864 @cindex swap encryption
16865 It is also desirable to encrypt swap space, since swap space may contain
16866 sensitive data. One way to accomplish that is to use a swap file in a
16867 file system on a device mapped via LUKS encryption. In this way, the
16868 swap file is encrypted because the entire device is encrypted.
16869 @xref{Swap Space}, or @xref{Preparing for Installation,,Disk
16870 Partitioning}, for an example.
16872 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
16873 may be declared as follows:
16877 (source (list "/dev/sda1" "/dev/sdb1"))
16878 (target "/dev/md0")
16879 (type raid-device-mapping))
16882 The @file{/dev/md0} device can then be used as the @code{device} of a
16883 @code{file-system} declaration (@pxref{File Systems}).
16884 Note that the RAID level need not be given; it is chosen during the
16885 initial creation and formatting of the RAID device and is determined
16886 automatically later.
16888 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
16889 be declared as follows:
16894 (targets (list "vg0-alpha" "vg0-beta"))
16895 (type lvm-device-mapping))
16898 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
16899 then be used as the @code{device} of a @code{file-system} declaration
16900 (@pxref{File Systems}).
16903 @section Swap Space
16906 Swap space, as it is commonly called, is a disk area specifically
16907 designated for paging: the process in charge of memory management
16908 (the Linux kernel or Hurd's default pager) can decide that some memory
16909 pages stored in RAM which belong to a running program but are unused
16910 should be stored on disk instead. It unloads those from the RAM,
16911 freeing up precious fast memory, and writes them to the swap space. If
16912 the program tries to access that very page, the memory management
16913 process loads it back into memory for the program to use.
16915 A common misconception about swap is that it is only useful when small
16916 amounts of RAM are available to the system. However, it should be noted
16917 that kernels often use all available RAM for disk access caching to make
16918 I/O faster, and thus paging out unused portions of program memory will
16919 expand the RAM available for such caching.
16921 For a more detailed description of how memory is managed from the
16922 viewpoint of a monolithic kernel, @xref{Memory
16923 Concepts,,, libc, The GNU C Library Reference Manual}.
16925 The Linux kernel has support for swap partitions and swap files: the
16926 former uses a whole disk partition for paging, whereas the second uses a
16927 file on a file system for that (the file system driver needs to support
16928 it). On a comparable setup, both have the same performance, so one
16929 should consider ease of use when deciding between them. Partitions are
16930 ``simpler'' and do not need file system support, but need to be
16931 allocated at disk formatting time (logical volumes notwithstanding),
16932 whereas files can be allocated and deallocated at any time.
16934 Note that swap space is not zeroed on shutdown, so sensitive data (such
16935 as passwords) may linger on it if it was paged out. As such, you should
16936 consider having your swap reside on an encrypted device (@pxref{Mapped
16939 @deftp {Data Type} swap-space
16940 Objects of this type represent swap spaces. They contain the following
16944 @item @code{target}
16945 The device or file to use, either a UUID, a @code{file-system-label} or
16946 a string, as in the definition of a @code{file-system} (@pxref{File
16949 @item @code{dependencies} (default: @code{'()})
16950 A list of @code{file-system} or @code{mapped-device} objects, upon which
16951 the availability of the space depends. Note that just like for
16952 @code{file-system} objects, dependencies which are needed for boot and
16953 mounted in early userspace are not managed by the Shepherd, and so
16954 automatically filtered out for you.
16956 @item @code{priority} (default: @code{#f})
16957 Only supported by the Linux kernel. Either @code{#f} to disable swap
16958 priority, or an integer between 0 and 32767. The kernel will first use
16959 swap spaces of higher priority when paging, and use same priority spaces
16960 on a round-robin basis. The kernel will use swap spaces without a set
16961 priority after prioritized spaces, and in the order that they appeared in
16964 @item @code{discard?} (default: @code{#f})
16965 Only supported by the Linux kernel. When true, the kernel will notify
16966 the disk controller of discarded pages, for example with the TRIM
16967 operation on Solid State Drives.
16972 Here are some examples:
16975 (swap-space (target (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
16978 Use the swap partition with the given UUID@. You can learn the UUID of a
16979 Linux swap partition by running @command{swaplabel @var{device}}, where
16980 @var{device} is the @file{/dev} file name of that partition.
16984 (target (file-system-label "swap"))
16985 (dependencies mapped-devices))
16988 Use the partition with label @code{swap}, which can be found after all
16989 the @var{mapped-devices} mapped devices have been opened. Again, the
16990 @command{swaplabel} command allows you to view and change the label of a
16991 Linux swap partition.
16993 Here's a more involved example with the corresponding @code{file-systems} part
16994 of an @code{operating-system} declaration.
16999 (device (file-system-label "root"))
17003 (device (file-system-label "btrfs"))
17004 (mount-point "/btrfs")
17010 (target "/btrfs/swapfile")
17011 (dependencies (filter (file-system-mount-point-predicate "/btrfs")
17015 Use the file @file{/btrfs/swapfile} as swap space, which depends on the
17016 file system mounted at @file{/btrfs}. Note how we use Guile's filter to
17017 select the file system in an elegant fashion!
17019 @node User Accounts
17020 @section User Accounts
17024 @cindex user accounts
17025 User accounts and groups are entirely managed through the
17026 @code{operating-system} declaration. They are specified with the
17027 @code{user-account} and @code{user-group} forms:
17033 (supplementary-groups '("wheel" ;allow use of sudo, etc.
17034 "audio" ;sound card
17035 "video" ;video devices such as webcams
17036 "cdrom")) ;the good ol' CD-ROM
17037 (comment "Bob's sister"))
17040 Here's a user account that uses a different shell and a custom home
17041 directory (the default would be @file{"/home/bob"}):
17047 (comment "Alice's bro")
17048 (shell (file-append zsh "/bin/zsh"))
17049 (home-directory "/home/robert"))
17052 When booting or upon completion of @command{guix system reconfigure},
17053 the system ensures that only the user accounts and groups specified in
17054 the @code{operating-system} declaration exist, and with the specified
17055 properties. Thus, account or group creations or modifications made by
17056 directly invoking commands such as @command{useradd} are lost upon
17057 reconfiguration or reboot. This ensures that the system remains exactly
17060 @deftp {Data Type} user-account
17061 Objects of this type represent user accounts. The following members may
17066 The name of the user account.
17070 This is the name (a string) or identifier (a number) of the user group
17071 this account belongs to.
17073 @item @code{supplementary-groups} (default: @code{'()})
17074 Optionally, this can be defined as a list of group names that this
17075 account belongs to.
17077 @item @code{uid} (default: @code{#f})
17078 This is the user ID for this account (a number), or @code{#f}. In the
17079 latter case, a number is automatically chosen by the system when the
17080 account is created.
17082 @item @code{comment} (default: @code{""})
17083 A comment about the account, such as the account owner's full name.
17085 Note that, for non-system accounts, users are free to change their real
17086 name as it appears in @file{/etc/passwd} using the @command{chfn}
17087 command. When they do, their choice prevails over the system
17088 administrator's choice; reconfiguring does @emph{not} change their name.
17090 @item @code{home-directory}
17091 This is the name of the home directory for the account.
17093 @item @code{create-home-directory?} (default: @code{#t})
17094 Indicates whether the home directory of this account should be created
17095 if it does not exist yet.
17097 @item @code{shell} (default: Bash)
17098 This is a G-expression denoting the file name of a program to be used as
17099 the shell (@pxref{G-Expressions}). For example, you would refer to the
17100 Bash executable like this:
17103 (file-append bash "/bin/bash")
17107 ... and to the Zsh executable like that:
17110 (file-append zsh "/bin/zsh")
17113 @item @code{system?} (default: @code{#f})
17114 This Boolean value indicates whether the account is a ``system''
17115 account. System accounts are sometimes treated specially; for instance,
17116 graphical login managers do not list them.
17118 @anchor{user-account-password}
17119 @cindex password, for user accounts
17120 @item @code{password} (default: @code{#f})
17121 You would normally leave this field to @code{#f}, initialize user
17122 passwords as @code{root} with the @command{passwd} command, and then let
17123 users change it with @command{passwd}. Passwords set with
17124 @command{passwd} are of course preserved across reboot and
17127 If you @emph{do} want to set an initial password for an account, then
17128 this field must contain the encrypted password, as a string. You can use the
17129 @code{crypt} procedure for this purpose:
17136 ;; Specify a SHA-512-hashed initial password.
17137 (password (crypt "InitialPassword!" "$6$abc")))
17141 The hash of this initial password will be available in a file in
17142 @file{/gnu/store}, readable by all the users, so this method must be used with
17146 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
17147 more information on password encryption, and @ref{Encryption,,, guile, GNU
17148 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
17154 User group declarations are even simpler:
17157 (user-group (name "students"))
17160 @deftp {Data Type} user-group
17161 This type is for, well, user groups. There are just a few fields:
17165 The name of the group.
17167 @item @code{id} (default: @code{#f})
17168 The group identifier (a number). If @code{#f}, a new number is
17169 automatically allocated when the group is created.
17171 @item @code{system?} (default: @code{#f})
17172 This Boolean value indicates whether the group is a ``system'' group.
17173 System groups have low numerical IDs.
17175 @item @code{password} (default: @code{#f})
17176 What, user groups can have a password? Well, apparently yes. Unless
17177 @code{#f}, this field specifies the password of the group.
17182 For convenience, a variable lists all the basic user groups one may
17185 @defvr {Scheme Variable} %base-groups
17186 This is the list of basic user groups that users and/or packages expect
17187 to be present on the system. This includes groups such as ``root'',
17188 ``wheel'', and ``users'', as well as groups used to control access to
17189 specific devices such as ``audio'', ``disk'', and ``cdrom''.
17192 @defvr {Scheme Variable} %base-user-accounts
17193 This is the list of basic system accounts that programs may expect to
17194 find on a GNU/Linux system, such as the ``nobody'' account.
17196 Note that the ``root'' account is not included here. It is a
17197 special-case and is automatically added whether or not it is specified.
17200 @node Keyboard Layout
17201 @section Keyboard Layout
17203 @cindex keyboard layout
17205 To specify what each key of your keyboard does, you need to tell the operating
17206 system what @dfn{keyboard layout} you want to use. The default, when nothing
17207 is specified, is the US English QWERTY layout for 105-key PC keyboards.
17208 However, German speakers will usually prefer the German QWERTZ layout, French
17209 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
17210 or bépo, and they might even want to further customize the effect of some of
17211 the keys. This section explains how to get that done.
17213 @cindex keyboard layout, definition
17214 There are three components that will want to know about your keyboard layout:
17218 The @emph{bootloader} may want to know what keyboard layout you want to use
17219 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
17220 you want, for instance, to make sure that you can type the passphrase of your
17221 encrypted root partition using the right layout.
17224 The @emph{operating system kernel}, Linux, will need that so that the console
17225 is properly configured (@pxref{operating-system Reference,
17226 @code{keyboard-layout}}).
17229 The @emph{graphical display server}, usually Xorg, also has its own idea of
17230 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
17233 Guix allows you to configure all three separately but, fortunately, it allows
17234 you to share the same keyboard layout for all three components.
17236 @cindex XKB, keyboard layouts
17237 Keyboard layouts are represented by records created by the
17238 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
17239 the X Keyboard extension (XKB), each layout has four attributes: a name (often
17240 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
17241 optional variant name, an optional keyboard model name, and a possibly empty
17242 list of additional options. In most cases the layout name is all you care
17245 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
17246 [#:model] [#:options '()]
17247 Return a new keyboard layout with the given @var{name} and @var{variant}.
17249 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
17250 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
17251 @code{xkeyboard-config} package for valid options.
17254 Here are a few examples:
17257 ;; The German QWERTZ layout. Here we assume a standard
17258 ;; "pc105" keyboard model.
17259 (keyboard-layout "de")
17261 ;; The bépo variant of the French layout.
17262 (keyboard-layout "fr" "bepo")
17264 ;; The Catalan layout.
17265 (keyboard-layout "es" "cat")
17267 ;; Arabic layout with "Alt-Shift" to switch to US layout.
17268 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
17270 ;; The Latin American Spanish layout. In addition, the
17271 ;; "Caps Lock" key is used as an additional "Ctrl" key,
17272 ;; and the "Menu" key is used as a "Compose" key to enter
17273 ;; accented letters.
17274 (keyboard-layout "latam"
17275 #:options '("ctrl:nocaps" "compose:menu"))
17277 ;; The Russian layout for a ThinkPad keyboard.
17278 (keyboard-layout "ru" #:model "thinkpad")
17280 ;; The "US international" layout, which is the US layout plus
17281 ;; dead keys to enter accented characters. This is for an
17282 ;; Apple MacBook keyboard.
17283 (keyboard-layout "us" "intl" #:model "macbook78")
17286 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
17287 for a complete list of supported layouts, variants, and models.
17289 @cindex keyboard layout, configuration
17290 Let's say you want your system to use the Turkish keyboard layout throughout
17291 your system---bootloader, console, and Xorg. Here's what your system
17292 configuration would look like:
17294 @findex set-xorg-configuration
17296 ;; Using the Turkish layout for the bootloader, the console,
17301 (keyboard-layout (keyboard-layout "tr")) ;for the console
17302 (bootloader (bootloader-configuration
17303 (bootloader grub-efi-bootloader)
17304 (targets '("/boot/efi"))
17305 (keyboard-layout keyboard-layout))) ;for GRUB
17306 (services (cons (set-xorg-configuration
17307 (xorg-configuration ;for Xorg
17308 (keyboard-layout keyboard-layout)))
17309 %desktop-services)))
17312 In the example above, for GRUB and for Xorg, we just refer to the
17313 @code{keyboard-layout} field defined above, but we could just as well refer to
17314 a different layout. The @code{set-xorg-configuration} procedure communicates
17315 the desired Xorg configuration to the graphical log-in manager, by default
17318 We've discussed how to specify the @emph{default} keyboard layout of your
17319 system when it starts, but you can also adjust it at run time:
17323 If you're using GNOME, its settings panel has a ``Region & Language'' entry
17324 where you can select one or more keyboard layouts.
17327 Under Xorg, the @command{setxkbmap} command (from the same-named package)
17328 allows you to change the current layout. For example, this is how you would
17329 change the layout to US Dvorak:
17332 setxkbmap us dvorak
17336 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
17337 console. However, note that @code{loadkeys} does @emph{not} use the XKB
17338 keyboard layout categorization described above. The command below loads the
17339 French bépo layout:
17350 A @dfn{locale} defines cultural conventions for a particular language
17351 and region of the world (@pxref{Locales,,, libc, The GNU C Library
17352 Reference Manual}). Each locale has a name that typically has the form
17353 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
17354 @code{fr_LU.utf8} designates the locale for the French language, with
17355 cultural conventions from Luxembourg, and using the UTF-8 encoding.
17357 @cindex locale definition
17358 Usually, you will want to specify the default locale for the machine
17359 using the @code{locale} field of the @code{operating-system} declaration
17360 (@pxref{operating-system Reference, @code{locale}}).
17362 The selected locale is automatically added to the @dfn{locale
17363 definitions} known to the system if needed, with its codeset inferred
17364 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
17365 @code{UTF-8} codeset. Additional locale definitions can be specified in
17366 the @code{locale-definitions} slot of @code{operating-system}---this is
17367 useful, for instance, if the codeset could not be inferred from the
17368 locale name. The default set of locale definitions includes some widely
17369 used locales, but not all the available locales, in order to save space.
17371 For instance, to add the North Frisian locale for Germany, the value of
17375 (cons (locale-definition
17376 (name "fy_DE.utf8") (source "fy_DE"))
17377 %default-locale-definitions)
17380 Likewise, to save space, one might want @code{locale-definitions} to
17381 list only the locales that are actually used, as in:
17384 (list (locale-definition
17385 (name "ja_JP.eucjp") (source "ja_JP")
17386 (charset "EUC-JP")))
17390 The compiled locale definitions are available at
17391 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
17392 version, which is the default location where the GNU@tie{}libc provided
17393 by Guix looks for locale data. This can be overridden using the
17394 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
17395 @env{LOCPATH} and locale packages}).
17397 The @code{locale-definition} form is provided by the @code{(gnu system
17398 locale)} module. Details are given below.
17400 @deftp {Data Type} locale-definition
17401 This is the data type of a locale definition.
17406 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
17407 Reference Manual}, for more information on locale names.
17409 @item @code{source}
17410 The name of the source for that locale. This is typically the
17411 @code{@var{language}_@var{territory}} part of the locale name.
17413 @item @code{charset} (default: @code{"UTF-8"})
17414 The ``character set'' or ``code set'' for that locale,
17415 @uref{https://www.iana.org/assignments/character-sets, as defined by
17421 @defvr {Scheme Variable} %default-locale-definitions
17422 A list of commonly used UTF-8 locales, used as the default
17423 value of the @code{locale-definitions} field of @code{operating-system}
17426 @cindex locale name
17427 @cindex normalized codeset in locale names
17428 These locale definitions use the @dfn{normalized codeset} for the part
17429 that follows the dot in the name (@pxref{Using gettextized software,
17430 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
17431 instance it has @code{uk_UA.utf8} but @emph{not}, say,
17432 @code{uk_UA.UTF-8}.
17435 @subsection Locale Data Compatibility Considerations
17437 @cindex incompatibility, of locale data
17438 @code{operating-system} declarations provide a @code{locale-libcs} field
17439 to specify the GNU@tie{}libc packages that are used to compile locale
17440 declarations (@pxref{operating-system Reference}). ``Why would I
17441 care?'', you may ask. Well, it turns out that the binary format of
17442 locale data is occasionally incompatible from one libc version to
17445 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
17446 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
17447 For instance, a program linked against libc version 2.21 is unable to
17448 read locale data produced with libc 2.22; worse, that program
17449 @emph{aborts} instead of simply ignoring the incompatible locale
17450 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
17451 the incompatible locale data, which is already an improvement.}.
17452 Similarly, a program linked against libc 2.22 can read most, but not
17453 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
17454 data is incompatible); thus calls to @code{setlocale} may fail, but
17455 programs will not abort.
17457 The ``problem'' with Guix is that users have a lot of freedom: They can
17458 choose whether and when to upgrade software in their profiles, and might
17459 be using a libc version different from the one the system administrator
17460 used to build the system-wide locale data.
17462 Fortunately, unprivileged users can also install their own locale data
17463 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
17464 @env{GUIX_LOCPATH} and locale packages}).
17466 Still, it is best if the system-wide locale data at
17467 @file{/run/current-system/locale} is built for all the libc versions
17468 actually in use on the system, so that all the programs can access
17469 it---this is especially crucial on a multi-user system. To do that, the
17470 administrator can specify several libc packages in the
17471 @code{locale-libcs} field of @code{operating-system}:
17474 (use-package-modules base)
17478 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
17481 This example would lead to a system containing locale definitions for
17482 both libc 2.21 and the current version of libc in
17483 @file{/run/current-system/locale}.
17489 @cindex system services
17490 An important part of preparing an @code{operating-system} declaration is
17491 listing @dfn{system services} and their configuration (@pxref{Using the
17492 Configuration System}). System services are typically daemons launched
17493 when the system boots, or other actions needed at that time---e.g.,
17494 configuring network access.
17496 Guix has a broad definition of ``service'' (@pxref{Service
17497 Composition}), but many services are managed by the GNU@tie{}Shepherd
17498 (@pxref{Shepherd Services}). On a running system, the @command{herd}
17499 command allows you to list the available services, show their status,
17500 start and stop them, or do other specific operations (@pxref{Jump
17501 Start,,, shepherd, The GNU Shepherd Manual}). For example:
17507 The above command, run as @code{root}, lists the currently defined
17508 services. The @command{herd doc} command shows a synopsis of the given
17509 service and its associated actions:
17513 Run libc's name service cache daemon (nscd).
17515 # herd doc nscd action invalidate
17516 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
17519 The @command{start}, @command{stop}, and @command{restart} sub-commands
17520 have the effect you would expect. For instance, the commands below stop
17521 the nscd service and restart the Xorg display server:
17525 Service nscd has been stopped.
17526 # herd restart xorg-server
17527 Service xorg-server has been stopped.
17528 Service xorg-server has been started.
17531 The following sections document the available services, starting with
17532 the core services, that may be used in an @code{operating-system}
17536 * Base Services:: Essential system services.
17537 * Scheduled Job Execution:: The mcron service.
17538 * Log Rotation:: The rottlog service.
17539 * Networking Setup:: Setting up network interfaces.
17540 * Networking Services:: Firewall, SSH daemon, etc.
17541 * Unattended Upgrades:: Automated system upgrades.
17542 * X Window:: Graphical display.
17543 * Printing Services:: Local and remote printer support.
17544 * Desktop Services:: D-Bus and desktop services.
17545 * Sound Services:: ALSA and Pulseaudio services.
17546 * Database Services:: SQL databases, key-value stores, etc.
17547 * Mail Services:: IMAP, POP3, SMTP, and all that.
17548 * Messaging Services:: Messaging services.
17549 * Telephony Services:: Telephony services.
17550 * File-Sharing Services:: File-sharing services.
17551 * Monitoring Services:: Monitoring services.
17552 * Kerberos Services:: Kerberos services.
17553 * LDAP Services:: LDAP services.
17554 * Web Services:: Web servers.
17555 * Certificate Services:: TLS certificates via Let's Encrypt.
17556 * DNS Services:: DNS daemons.
17557 * VNC Services:: VNC daemons.
17558 * VPN Services:: VPN daemons.
17559 * Network File System:: NFS related services.
17560 * Samba Services:: Samba services.
17561 * Continuous Integration:: Cuirass and Laminar services.
17562 * Power Management Services:: Extending battery life.
17563 * Audio Services:: The MPD.
17564 * Virtualization Services:: Virtualization services.
17565 * Version Control Services:: Providing remote access to Git repositories.
17566 * Game Services:: Game servers.
17567 * PAM Mount Service:: Service to mount volumes when logging in.
17568 * Guix Services:: Services relating specifically to Guix.
17569 * Linux Services:: Services tied to the Linux kernel.
17570 * Hurd Services:: Services specific for a Hurd System.
17571 * Miscellaneous Services:: Other services.
17574 @node Base Services
17575 @subsection Base Services
17577 The @code{(gnu services base)} module provides definitions for the basic
17578 services that one expects from the system. The services exported by
17579 this module are listed below.
17581 @defvr {Scheme Variable} %base-services
17582 This variable contains a list of basic services (@pxref{Service Types
17583 and Services}, for more information on service objects) one would
17584 expect from the system: a login service (mingetty) on each tty, syslogd,
17585 the libc name service cache daemon (nscd), the udev device manager, and
17588 This is the default value of the @code{services} field of
17589 @code{operating-system} declarations. Usually, when customizing a
17590 system, you will want to append services to @code{%base-services}, like
17594 (append (list (service avahi-service-type)
17595 (service openssh-service-type))
17600 @defvr {Scheme Variable} special-files-service-type
17601 This is the service that sets up ``special files'' such as
17602 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
17604 The value associated with @code{special-files-service-type} services
17605 must be a list of tuples where the first element is the ``special file''
17606 and the second element is its target. By default it is:
17608 @cindex @file{/bin/sh}
17609 @cindex @file{sh}, in @file{/bin}
17611 `(("/bin/sh" ,(file-append bash "/bin/sh")))
17614 @cindex @file{/usr/bin/env}
17615 @cindex @file{env}, in @file{/usr/bin}
17616 If you want to add, say, @code{/usr/bin/env} to your system, you can
17620 `(("/bin/sh" ,(file-append bash "/bin/sh"))
17621 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
17624 Since this is part of @code{%base-services}, you can use
17625 @code{modify-services} to customize the set of special files
17626 (@pxref{Service Reference, @code{modify-services}}). But the simple way
17627 to add a special file is @i{via} the @code{extra-special-file} procedure
17631 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
17632 Use @var{target} as the ``special file'' @var{file}.
17634 For example, adding the following lines to the @code{services} field of
17635 your operating system declaration leads to a @file{/usr/bin/env}
17639 (extra-special-file "/usr/bin/env"
17640 (file-append coreutils "/bin/env"))
17644 @deffn {Scheme Procedure} host-name-service @var{name}
17645 Return a service that sets the host name to @var{name}.
17648 @defvr {Scheme Variable} console-font-service-type
17649 Install the given fonts on the specified ttys (fonts are per
17650 virtual console on the kernel Linux). The value of this service is a list of
17651 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
17652 package or any valid argument to @command{setfont}, as in this example:
17655 `(("tty1" . "LatGrkCyr-8x16")
17656 ("tty2" . ,(file-append
17658 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
17659 ("tty3" . ,(file-append
17661 "/share/consolefonts/ter-132n"))) ; for HDPI
17665 @deffn {Scheme Procedure} login-service @var{config}
17666 Return a service to run login according to @var{config}, a
17667 @code{<login-configuration>} object, which specifies the message of the day,
17668 among other things.
17671 @deftp {Data Type} login-configuration
17672 This is the data type representing the configuration of login.
17677 @cindex message of the day
17678 A file-like object containing the ``message of the day''.
17680 @item @code{allow-empty-passwords?} (default: @code{#t})
17681 Allow empty passwords by default so that first-time users can log in when
17682 the 'root' account has just been created.
17687 @deffn {Scheme Procedure} mingetty-service @var{config}
17688 Return a service to run mingetty according to @var{config}, a
17689 @code{<mingetty-configuration>} object, which specifies the tty to run, among
17693 @deftp {Data Type} mingetty-configuration
17694 This is the data type representing the configuration of Mingetty, which
17695 provides the default implementation of virtual console log-in.
17700 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
17702 @item @code{auto-login} (default: @code{#f})
17703 When true, this field must be a string denoting the user name under
17704 which the system automatically logs in. When it is @code{#f}, a
17705 user name and password must be entered to log in.
17707 @item @code{login-program} (default: @code{#f})
17708 This must be either @code{#f}, in which case the default log-in program
17709 is used (@command{login} from the Shadow tool suite), or a gexp denoting
17710 the name of the log-in program.
17712 @item @code{login-pause?} (default: @code{#f})
17713 When set to @code{#t} in conjunction with @var{auto-login}, the user
17714 will have to press a key before the log-in shell is launched.
17716 @item @code{clear-on-logout?} (default: @code{#t})
17717 When set to @code{#t}, the screen will be cleared after logout.
17719 @item @code{mingetty} (default: @var{mingetty})
17720 The Mingetty package to use.
17725 @deffn {Scheme Procedure} agetty-service @var{config}
17726 Return a service to run agetty according to @var{config}, an
17727 @code{<agetty-configuration>} object, which specifies the tty to run,
17728 among other things.
17731 @deftp {Data Type} agetty-configuration
17732 This is the data type representing the configuration of agetty, which
17733 implements virtual and serial console log-in. See the @code{agetty(8)}
17734 man page for more information.
17739 The name of the console this agetty runs on, as a string---e.g.,
17740 @code{"ttyS0"}. This argument is optional, it will default to
17741 a reasonable default serial port used by the kernel Linux.
17743 For this, if there is a value for an option @code{agetty.tty} in the kernel
17744 command line, agetty will extract the device name of the serial port
17745 from it and use that.
17747 If not and if there is a value for an option @code{console} with a tty in
17748 the Linux command line, agetty will extract the device name of the
17749 serial port from it and use that.
17751 In both cases, agetty will leave the other serial device settings
17752 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
17755 @item @code{baud-rate} (default: @code{#f})
17756 A string containing a comma-separated list of one or more baud rates, in
17759 @item @code{term} (default: @code{#f})
17760 A string containing the value used for the @env{TERM} environment
17763 @item @code{eight-bits?} (default: @code{#f})
17764 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
17767 @item @code{auto-login} (default: @code{#f})
17768 When passed a login name, as a string, the specified user will be logged
17769 in automatically without prompting for their login name or password.
17771 @item @code{no-reset?} (default: @code{#f})
17772 When @code{#t}, don't reset terminal cflags (control modes).
17774 @item @code{host} (default: @code{#f})
17775 This accepts a string containing the ``login_host'', which will be written
17776 into the @file{/var/run/utmpx} file.
17778 @item @code{remote?} (default: @code{#f})
17779 When set to @code{#t} in conjunction with @var{host}, this will add an
17780 @code{-r} fakehost option to the command line of the login program
17781 specified in @var{login-program}.
17783 @item @code{flow-control?} (default: @code{#f})
17784 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
17786 @item @code{no-issue?} (default: @code{#f})
17787 When set to @code{#t}, the contents of the @file{/etc/issue} file will
17788 not be displayed before presenting the login prompt.
17790 @item @code{init-string} (default: @code{#f})
17791 This accepts a string that will be sent to the tty or modem before
17792 sending anything else. It can be used to initialize a modem.
17794 @item @code{no-clear?} (default: @code{#f})
17795 When set to @code{#t}, agetty will not clear the screen before showing
17798 @item @code{login-program} (default: (file-append shadow "/bin/login"))
17799 This must be either a gexp denoting the name of a log-in program, or
17800 unset, in which case the default value is the @command{login} from the
17803 @item @code{local-line} (default: @code{#f})
17804 Control the CLOCAL line flag. This accepts one of three symbols as
17805 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
17806 the default value chosen by agetty is @code{'auto}.
17808 @item @code{extract-baud?} (default: @code{#f})
17809 When set to @code{#t}, instruct agetty to try to extract the baud rate
17810 from the status messages produced by certain types of modems.
17812 @item @code{skip-login?} (default: @code{#f})
17813 When set to @code{#t}, do not prompt the user for a login name. This
17814 can be used with @var{login-program} field to use non-standard login
17817 @item @code{no-newline?} (default: @code{#f})
17818 When set to @code{#t}, do not print a newline before printing the
17819 @file{/etc/issue} file.
17821 @c Is this dangerous only when used with login-program, or always?
17822 @item @code{login-options} (default: @code{#f})
17823 This option accepts a string containing options that are passed to the
17824 login program. When used with the @var{login-program}, be aware that a
17825 malicious user could try to enter a login name containing embedded
17826 options that could be parsed by the login program.
17828 @item @code{login-pause} (default: @code{#f})
17829 When set to @code{#t}, wait for any key before showing the login prompt.
17830 This can be used in conjunction with @var{auto-login} to save memory by
17831 lazily spawning shells.
17833 @item @code{chroot} (default: @code{#f})
17834 Change root to the specified directory. This option accepts a directory
17837 @item @code{hangup?} (default: @code{#f})
17838 Use the Linux system call @code{vhangup} to do a virtual hangup of the
17839 specified terminal.
17841 @item @code{keep-baud?} (default: @code{#f})
17842 When set to @code{#t}, try to keep the existing baud rate. The baud
17843 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
17846 @item @code{timeout} (default: @code{#f})
17847 When set to an integer value, terminate if no user name could be read
17848 within @var{timeout} seconds.
17850 @item @code{detect-case?} (default: @code{#f})
17851 When set to @code{#t}, turn on support for detecting an uppercase-only
17852 terminal. This setting will detect a login name containing only
17853 uppercase letters as indicating an uppercase-only terminal and turn on
17854 some upper-to-lower case conversions. Note that this will not support
17855 Unicode characters.
17857 @item @code{wait-cr?} (default: @code{#f})
17858 When set to @code{#t}, wait for the user or modem to send a
17859 carriage-return or linefeed character before displaying
17860 @file{/etc/issue} or login prompt. This is typically used with the
17861 @var{init-string} option.
17863 @item @code{no-hints?} (default: @code{#f})
17864 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
17867 @item @code{no-hostname?} (default: @code{#f})
17868 By default, the hostname is printed. When this option is set to
17869 @code{#t}, no hostname will be shown at all.
17871 @item @code{long-hostname?} (default: @code{#f})
17872 By default, the hostname is only printed until the first dot. When this
17873 option is set to @code{#t}, the fully qualified hostname by
17874 @code{gethostname} or @code{getaddrinfo} is shown.
17876 @item @code{erase-characters} (default: @code{#f})
17877 This option accepts a string of additional characters that should be
17878 interpreted as backspace when the user types their login name.
17880 @item @code{kill-characters} (default: @code{#f})
17881 This option accepts a string that should be interpreted to mean ``ignore
17882 all previous characters'' (also called a ``kill'' character) when the user
17883 types their login name.
17885 @item @code{chdir} (default: @code{#f})
17886 This option accepts, as a string, a directory path that will be changed
17889 @item @code{delay} (default: @code{#f})
17890 This options accepts, as an integer, the number of seconds to sleep
17891 before opening the tty and displaying the login prompt.
17893 @item @code{nice} (default: @code{#f})
17894 This option accepts, as an integer, the nice value with which to run the
17895 @command{login} program.
17897 @item @code{extra-options} (default: @code{'()})
17898 This option provides an ``escape hatch'' for the user to provide arbitrary
17899 command-line arguments to @command{agetty} as a list of strings.
17901 @item @code{shepherd-requirement} (default: @code{'()})
17902 The option can be used to provides extra shepherd requirements (for example
17903 @code{'syslogd}) to the respective @code{'term-}* shepherd service.
17908 @deffn {Scheme Procedure} kmscon-service-type @var{config}
17909 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
17910 according to @var{config}, a @code{<kmscon-configuration>} object, which
17911 specifies the tty to run, among other things.
17914 @deftp {Data Type} kmscon-configuration
17915 This is the data type representing the configuration of Kmscon, which
17916 implements virtual console log-in.
17920 @item @code{virtual-terminal}
17921 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
17923 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
17924 A gexp denoting the name of the log-in program. The default log-in program is
17925 @command{login} from the Shadow tool suite.
17927 @item @code{login-arguments} (default: @code{'("-p")})
17928 A list of arguments to pass to @command{login}.
17930 @item @code{auto-login} (default: @code{#f})
17931 When passed a login name, as a string, the specified user will be logged
17932 in automatically without prompting for their login name or password.
17934 @item @code{hardware-acceleration?} (default: #f)
17935 Whether to use hardware acceleration.
17937 @item @code{font-engine} (default: @code{"pango"})
17938 Font engine used in Kmscon.
17940 @item @code{font-size} (default: @code{12})
17941 Font size used in Kmscon.
17943 @item @code{keyboard-layout} (default: @code{#f})
17944 If this is @code{#f}, Kmscon uses the default keyboard layout---usually US
17945 English (``qwerty'') for a 105-key PC keyboard.
17947 Otherwise this must be a @code{keyboard-layout} object specifying the
17948 keyboard layout. @xref{Keyboard Layout}, for more information on how to
17949 specify the keyboard layout.
17951 @item @code{kmscon} (default: @var{kmscon})
17952 The Kmscon package to use.
17957 @cindex name service cache daemon
17959 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
17960 [#:name-services '()]
17961 Return a service that runs the libc name service cache daemon (nscd) with the
17962 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
17963 Service Switch}, for an example.
17965 For convenience, the Shepherd service for nscd provides the following actions:
17969 @cindex cache invalidation, nscd
17970 @cindex nscd, cache invalidation
17971 This invalidate the given cache. For instance, running:
17974 herd invalidate nscd hosts
17978 invalidates the host name lookup cache of nscd.
17981 Running @command{herd statistics nscd} displays information about nscd usage
17987 @defvr {Scheme Variable} %nscd-default-configuration
17988 This is the default @code{<nscd-configuration>} value (see below) used
17989 by @code{nscd-service}. It uses the caches defined by
17990 @code{%nscd-default-caches}; see below.
17993 @deftp {Data Type} nscd-configuration
17994 This is the data type representing the name service cache daemon (nscd)
17999 @item @code{name-services} (default: @code{'()})
18000 List of packages denoting @dfn{name services} that must be visible to
18001 the nscd---e.g., @code{(list @var{nss-mdns})}.
18003 @item @code{glibc} (default: @var{glibc})
18004 Package object denoting the GNU C Library providing the @command{nscd}
18007 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
18008 Name of the nscd log file. This is where debugging output goes when
18009 @code{debug-level} is strictly positive.
18011 @item @code{debug-level} (default: @code{0})
18012 Integer denoting the debugging levels. Higher numbers mean that more
18013 debugging output is logged.
18015 @item @code{caches} (default: @code{%nscd-default-caches})
18016 List of @code{<nscd-cache>} objects denoting things to be cached; see
18022 @deftp {Data Type} nscd-cache
18023 Data type representing a cache database of nscd and its parameters.
18027 @item @code{database}
18028 This is a symbol representing the name of the database to be cached.
18029 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
18030 @code{services}, which designate the corresponding NSS database
18031 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
18033 @item @code{positive-time-to-live}
18034 @itemx @code{negative-time-to-live} (default: @code{20})
18035 A number representing the number of seconds during which a positive or
18036 negative lookup result remains in cache.
18038 @item @code{check-files?} (default: @code{#t})
18039 Whether to check for updates of the files corresponding to
18042 For instance, when @var{database} is @code{hosts}, setting this flag
18043 instructs nscd to check for updates in @file{/etc/hosts} and to take
18046 @item @code{persistent?} (default: @code{#t})
18047 Whether the cache should be stored persistently on disk.
18049 @item @code{shared?} (default: @code{#t})
18050 Whether the cache should be shared among users.
18052 @item @code{max-database-size} (default: 32@tie{}MiB)
18053 Maximum size in bytes of the database cache.
18055 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
18056 @c settings, so leave them out.
18061 @defvr {Scheme Variable} %nscd-default-caches
18062 List of @code{<nscd-cache>} objects used by default by
18063 @code{nscd-configuration} (see above).
18065 It enables persistent and aggressive caching of service and host name
18066 lookups. The latter provides better host name lookup performance,
18067 resilience in the face of unreliable name servers, and also better
18068 privacy---often the result of host name lookups is in local cache, so
18069 external name servers do not even need to be queried.
18072 @anchor{syslog-configuration-type}
18075 @deftp {Data Type} syslog-configuration
18076 This data type represents the configuration of the syslog daemon.
18079 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
18080 The syslog daemon to use.
18082 @item @code{config-file} (default: @code{%default-syslog.conf})
18083 The syslog configuration file to use.
18088 @anchor{syslog-service}
18090 @deffn {Scheme Procedure} syslog-service @var{config}
18091 Return a service that runs a syslog daemon according to @var{config}.
18093 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
18094 information on the configuration file syntax.
18097 @defvr {Scheme Variable} guix-service-type
18098 This is the type of the service that runs the build daemon,
18099 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
18100 @code{guix-configuration} record as described below.
18103 @anchor{guix-configuration-type}
18104 @deftp {Data Type} guix-configuration
18105 This data type represents the configuration of the Guix build daemon.
18106 @xref{Invoking guix-daemon}, for more information.
18109 @item @code{guix} (default: @var{guix})
18110 The Guix package to use.
18112 @item @code{build-group} (default: @code{"guixbuild"})
18113 Name of the group for build user accounts.
18115 @item @code{build-accounts} (default: @code{10})
18116 Number of build user accounts to create.
18118 @item @code{authorize-key?} (default: @code{#t})
18119 @cindex substitutes, authorization thereof
18120 Whether to authorize the substitute keys listed in
18121 @code{authorized-keys}---by default that of
18122 @code{@value{SUBSTITUTE-SERVER-1}} and
18123 @code{@value{SUBSTITUTE-SERVER-2}}
18124 (@pxref{Substitutes}).
18126 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
18127 changed by invoking @command{guix archive --authorize}. You must
18128 instead adjust @code{guix-configuration} as you wish and reconfigure the
18129 system. This ensures that your operating system configuration file is
18133 When booting or reconfiguring to a system where @code{authorize-key?}
18134 is true, the existing @file{/etc/guix/acl} file is backed up as
18135 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
18136 file. This is to facilitate migration from earlier versions, which
18137 allowed for in-place modifications to @file{/etc/guix/acl}.
18140 @vindex %default-authorized-guix-keys
18141 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
18142 The list of authorized key files for archive imports, as a list of
18143 string-valued gexps (@pxref{Invoking guix archive}). By default, it
18144 contains that of @code{@value{SUBSTITUTE-SERVER-1}} and
18145 @code{@value{SUBSTITUTE-SERVER-2}} (@pxref{Substitutes}). See
18146 @code{substitute-urls} below for an example on how to change it.
18148 @item @code{use-substitutes?} (default: @code{#t})
18149 Whether to use substitutes.
18151 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
18152 The list of URLs where to look for substitutes by default.
18154 Suppose you would like to fetch substitutes from @code{guix.example.org}
18155 in addition to @code{@value{SUBSTITUTE-SERVER-1}}. You will need to do
18156 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
18157 and (2) authorize its signing key, having done appropriate checks
18158 (@pxref{Substitute Server Authorization}). The configuration below does
18162 (guix-configuration
18164 (append (list "https://guix.example.org")
18165 %default-substitute-urls))
18167 (append (list (local-file "./guix.example.org-key.pub"))
18168 %default-authorized-guix-keys)))
18171 This example assumes that the file @file{./guix.example.org-key.pub}
18172 contains the public key that @code{guix.example.org} uses to sign
18175 @item @code{generate-substitute-key?} (default: @code{#t})
18176 Whether to generate a @dfn{substitute key pair} under
18177 @file{/etc/guix/signing-key.pub} and @file{/etc/guix/signing-key.sec} if
18178 there is not already one.
18180 This key pair is used when exporting store items, for instance with
18181 @command{guix publish} (@pxref{Invoking guix publish}) or @command{guix
18182 archive} (@pxref{Invoking guix archive}). Generating a key pair takes a
18183 few seconds when enough entropy is available and is only done once; you
18184 might want to turn it off for instance in a virtual machine that does
18185 not need it and where the extra boot time is a problem.
18187 @item @code{max-silent-time} (default: @code{0})
18188 @itemx @code{timeout} (default: @code{0})
18189 The number of seconds of silence and the number of seconds of activity,
18190 respectively, after which a build process times out. A value of zero
18191 disables the timeout.
18193 @item @code{log-compression} (default: @code{'gzip})
18194 The type of compression used for build logs---one of @code{gzip},
18195 @code{bzip2}, or @code{none}.
18197 @item @code{discover?} (default: @code{#f})
18198 Whether to discover substitute servers on the local network using mDNS
18201 @item @code{extra-options} (default: @code{'()})
18202 List of extra command-line options for @command{guix-daemon}.
18204 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
18205 File where @command{guix-daemon}'s standard output and standard error
18208 @cindex HTTP proxy, for @code{guix-daemon}
18209 @cindex proxy, for @code{guix-daemon} HTTP access
18210 @item @code{http-proxy} (default: @code{#f})
18211 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
18212 derivations and substitutes.
18214 It is also possible to change the daemon's proxy at run time through the
18215 @code{set-http-proxy} action, which restarts it:
18218 herd set-http-proxy guix-daemon http://localhost:8118
18221 To clear the proxy settings, run:
18224 herd set-http-proxy guix-daemon
18227 @item @code{tmpdir} (default: @code{#f})
18228 A directory path where the @command{guix-daemon} will perform builds.
18233 @deftp {Data Type} guix-extension
18235 This data type represents the parameters of the Guix build daemon that
18236 are extendable. This is the type of the object that must be used within
18237 a guix service extension.
18238 @xref{Service Composition}, for more information.
18241 @item @code{authorized-keys} (default: @code{'()})
18242 A list of file-like objects where each element contains a public key.
18244 @item @code{substitute-urls} (default: @code{'()})
18245 A list of strings where each element is a substitute URL.
18247 @item @code{chroot-directories} (default: @code{'()})
18248 A list of file-like objects or strings pointing to additional directories the build daemon can use.
18252 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
18253 Run @var{udev}, which populates the @file{/dev} directory dynamically.
18254 udev rules can be provided as a list of files through the @var{rules}
18255 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
18256 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
18257 creation of such rule files.
18259 The @command{herd rules udev} command, as root, returns the name of the
18260 directory containing all the active udev rules.
18263 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
18264 Return a udev-rule file named @var{file-name} containing the rules
18265 defined by the @var{contents} literal.
18267 In the following example, a rule for a USB device is defined to be
18268 stored in the file @file{90-usb-thing.rules}. The rule runs a script
18269 upon detecting a USB device with a given product identifier.
18272 (define %example-udev-rule
18274 "90-usb-thing.rules"
18275 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
18276 "ATTR@{product@}==\"Example\", "
18277 "RUN+=\"/path/to/script\"")))
18281 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
18282 [#:groups @var{groups}]
18283 Return a service that extends @code{udev-service-type } with @var{rules}
18284 and @code{account-service-type} with @var{groups} as system groups.
18285 This works by creating a singleton service type
18286 @code{@var{name}-udev-rules}, of which the returned service is an
18289 Here we show how it can be used to extend @code{udev-service-type} with the
18290 previously defined rule @code{%example-udev-rule}.
18296 (cons (udev-rules-service 'usb-thing %example-udev-rule)
18297 %desktop-services)))
18301 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
18302 Return a udev file named @var{file-name} containing the rules defined
18303 within @var{file}, a file-like object.
18305 The following example showcases how we can use an existing rule file.
18308 (use-modules (guix download) ;for url-fetch
18309 (guix packages) ;for origin
18312 (define %android-udev-rules
18314 "51-android-udev.rules"
18315 (let ((version "20170910"))
18318 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
18319 "android-udev-rules/" version "/51-android.rules"))
18321 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
18325 Additionally, Guix package definitions can be included in @var{rules} in
18326 order to extend the udev rules with the definitions found under their
18327 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
18328 @var{file->udev-rule} example, we could have used the
18329 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
18330 packages android)} module.
18332 The following example shows how to use the @var{android-udev-rules}
18333 package so that the Android tool @command{adb} can detect devices
18334 without root privileges. It also details how to create the
18335 @code{adbusers} group, which is required for the proper functioning of
18336 the rules defined within the @code{android-udev-rules} package. To
18337 create such a group, we must define it both as part of the
18338 @code{supplementary-groups} of our @code{user-account} declaration, as
18339 well as in the @var{groups} of the @code{udev-rules-service} procedure.
18342 (use-modules (gnu packages android) ;for android-udev-rules
18343 (gnu system shadow) ;for user-group
18348 (users (cons (user-account
18350 (supplementary-groups
18351 '("adbusers" ;for adb
18352 "wheel" "netdev" "audio" "video")))))
18355 (cons (udev-rules-service 'android android-udev-rules
18356 #:groups '("adbusers"))
18357 %desktop-services)))
18360 @defvr {Scheme Variable} urandom-seed-service-type
18361 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
18362 when rebooting. It also tries to seed @file{/dev/urandom} from
18363 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
18367 @defvr {Scheme Variable} %random-seed-file
18368 This is the name of the file where some random bytes are saved by
18369 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
18370 It defaults to @file{/var/lib/random-seed}.
18375 @defvr {Scheme Variable} gpm-service-type
18376 This is the type of the service that runs GPM, the @dfn{general-purpose
18377 mouse daemon}, which provides mouse support to the Linux console. GPM
18378 allows users to use the mouse in the console, notably to select, copy,
18381 The value for services of this type must be a @code{gpm-configuration}
18382 (see below). This service is not part of @code{%base-services}.
18385 @deftp {Data Type} gpm-configuration
18386 Data type representing the configuration of GPM.
18389 @item @code{options} (default: @code{%default-gpm-options})
18390 Command-line options passed to @command{gpm}. The default set of
18391 options instruct @command{gpm} to listen to mouse events on
18392 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
18395 @item @code{gpm} (default: @code{gpm})
18396 The GPM package to use.
18401 @anchor{guix-publish-service-type}
18402 @deffn {Scheme Variable} guix-publish-service-type
18403 This is the service type for @command{guix publish} (@pxref{Invoking
18404 guix publish}). Its value must be a @code{guix-publish-configuration}
18405 object, as described below.
18407 This assumes that @file{/etc/guix} already contains a signing key pair as
18408 created by @command{guix archive --generate-key} (@pxref{Invoking guix
18409 archive}). If that is not the case, the service will fail to start.
18412 @deftp {Data Type} guix-publish-configuration
18413 Data type representing the configuration of the @code{guix publish}
18417 @item @code{guix} (default: @code{guix})
18418 The Guix package to use.
18420 @item @code{port} (default: @code{80})
18421 The TCP port to listen for connections.
18423 @item @code{host} (default: @code{"localhost"})
18424 The host (and thus, network interface) to listen to. Use
18425 @code{"0.0.0.0"} to listen on all the network interfaces.
18427 @item @code{advertise?} (default: @code{#f})
18428 When true, advertise the service on the local network @i{via} the DNS-SD
18429 protocol, using Avahi.
18431 This allows neighboring Guix devices with discovery on (see
18432 @code{guix-configuration} above) to discover this @command{guix publish}
18433 instance and to automatically download substitutes from it.
18435 @item @code{compression} (default: @code{'(("gzip" 3) ("zstd" 3))})
18436 This is a list of compression method/level tuple used when compressing
18437 substitutes. For example, to compress all substitutes with @emph{both} lzip
18438 at level 7 and gzip at level 9, write:
18441 '(("lzip" 7) ("gzip" 9))
18444 Level 9 achieves the best compression ratio at the expense of increased CPU
18445 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
18446 publish}, for more information on the available compression methods and
18447 the tradeoffs involved.
18449 An empty list disables compression altogether.
18451 @item @code{nar-path} (default: @code{"nar"})
18452 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
18453 publish, @option{--nar-path}}, for details.
18455 @item @code{cache} (default: @code{#f})
18456 When it is @code{#f}, disable caching and instead generate archives on
18457 demand. Otherwise, this should be the name of a directory---e.g.,
18458 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
18459 archives and meta-data ready to be sent. @xref{Invoking guix publish,
18460 @option{--cache}}, for more information on the tradeoffs involved.
18462 @item @code{workers} (default: @code{#f})
18463 When it is an integer, this is the number of worker threads used for
18464 caching; when @code{#f}, the number of processors is used.
18465 @xref{Invoking guix publish, @option{--workers}}, for more information.
18467 @item @code{cache-bypass-threshold} (default: 10 MiB)
18468 When @code{cache} is true, this is the maximum size in bytes of a store
18469 item for which @command{guix publish} may bypass its cache in case of a
18470 cache miss. @xref{Invoking guix publish,
18471 @option{--cache-bypass-threshold}}, for more information.
18473 @item @code{ttl} (default: @code{#f})
18474 When it is an integer, this denotes the @dfn{time-to-live} in seconds
18475 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
18476 for more information.
18478 @item @code{negative-ttl} (default: @code{#f})
18479 When it is an integer, this denotes the @dfn{time-to-live} in
18480 seconds for the negative lookups. @xref{Invoking guix publish,
18481 @option{--negative-ttl}}, for more information.
18485 @anchor{rngd-service}
18486 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
18487 [#:device "/dev/hwrng"]
18488 Return a service that runs the @command{rngd} program from @var{rng-tools}
18489 to add @var{device} to the kernel's entropy pool. The service will fail if
18490 @var{device} does not exist.
18493 @anchor{pam-limits-service}
18494 @cindex session limits
18500 @cindex open file descriptors
18501 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
18503 Return a service that installs a configuration file for the
18504 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
18505 @code{pam_limits} module}. The procedure optionally takes a list of
18506 @code{pam-limits-entry} values, which can be used to specify
18507 @code{ulimit} limits and @code{nice} priority limits to user sessions.
18509 The following limits definition sets two hard and soft limits for all
18510 login sessions of users in the @code{realtime} group:
18513 (pam-limits-service
18515 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
18516 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
18519 The first entry increases the maximum realtime priority for
18520 non-privileged processes; the second entry lifts any restriction of the
18521 maximum address space that can be locked in memory. These settings are
18522 commonly used for real-time audio systems.
18524 Another useful example is raising the maximum number of open file
18525 descriptors that can be used:
18528 (pam-limits-service
18530 (pam-limits-entry "*" 'both 'nofile 100000)))
18533 In the above example, the asterisk means the limit should apply to any
18534 user. It is important to ensure the chosen value doesn't exceed the
18535 maximum system value visible in the @file{/proc/sys/fs/file-max} file,
18536 else the users would be prevented from login in. For more information
18537 about the Pluggable Authentication Module (PAM) limits, refer to the
18538 @samp{pam_limits} man page from the @code{linux-pam} package.
18541 @defvr {Scheme Variable} greetd-service-type
18542 @uref{https://git.sr.ht/~kennylevinsen/greetd, @code{greetd}} is a minimal and
18543 flexible login manager daemon, that makes no assumptions about what you
18546 If you can run it from your shell in a TTY, greetd can start it. If it
18547 can be taught to speak a simple JSON-based IPC protocol, then it can be
18550 @code{greetd-service-type} provides necessary infrastructure for logging
18551 in users, including:
18555 @code{greetd} PAM service
18558 Special variation of @code{pam-mount} to mount @code{XDG_RUNTIME_DIR}
18561 Here is example of switching from @code{mingetty-service-type} to
18562 @code{greetd-service-type}, and how different terminals could be:
18566 (modify-services %base-services
18567 ;; greetd-service-type provides "greetd" PAM service
18568 (delete login-service-type)
18569 ;; and can be used in place of mingetty-service-type
18570 (delete mingetty-service-type))
18572 (service greetd-service-type
18573 (greetd-configuration
18576 ;; we can make any terminal active by default
18577 (greetd-terminal-configuration (terminal-vt "1") (terminal-switch #t))
18578 ;; we can make environment without XDG_RUNTIME_DIR set
18579 ;; even provide our own environment variables
18580 (greetd-terminal-configuration
18582 (default-session-command
18583 (greetd-agreety-session
18584 (extra-env '(("MY_VAR" . "1")))
18586 ;; we can use different shell instead of default bash
18587 (greetd-terminal-configuration
18589 (default-session-command
18590 (greetd-agreety-session (command (file-append zsh "/bin/zsh")))))
18591 ;; we can use any other executable command as greeter
18592 (greetd-terminal-configuration
18594 (default-session-command (program-file "my-noop-greeter" #~(exit))))
18595 (greetd-terminal-configuration (terminal-vt "5"))
18596 (greetd-terminal-configuration (terminal-vt "6"))))))
18597 ;; mingetty-service-type can be used in parallel
18598 ;; if needed to do so, do not (delete login-service-type)
18599 ;; as illustrated above
18600 #| (service mingetty-service-type (mingetty-configuration (tty "tty8"))) |#))
18604 @deftp {Data Type} greetd-configuration
18605 Configuration record for the @code{greetd-service-type}.
18609 A file-like object containing the ``message of the day''.
18611 @item @code{allow-empty-passwords?} (default: @code{#t})
18612 Allow empty passwords by default so that first-time users can log in when
18613 the 'root' account has just been created.
18615 @item @code{terminals} (default: @code{'()})
18616 List of @code{greetd-terminal-configuration} per terminal for which
18617 @code{greetd} should be started.
18619 @item @code{greeter-supplementary-groups} (default: @code{'()})
18620 List of groups which should be added to @code{greeter} user. For instance:
18622 (greeter-supplementary-groups '("seat" "video"))
18624 Note that this example will fail if @code{seat} group does not exist.
18628 @deftp {Data Type} greetd-terminal-configuration
18629 Configuration record for per terminal greetd daemon service.
18632 @item @code{greetd} (default: @code{greetd})
18633 The greetd package to use.
18635 @item @code{config-file-name}
18636 Configuration file name to use for greetd daemon. Generally, autogenerated
18637 derivation based on @code{terminal-vt} value.
18639 @item @code{log-file-name}
18640 Log file name to use for greetd daemon. Generally, autogenerated
18641 name based on @code{terminal-vt} value.
18643 @item @code{terminal-vt} (default: @samp{"7"})
18644 The VT to run on. Use of a specific VT with appropriate conflict avoidance
18647 @item @code{terminal-switch} (default: @code{#f})
18648 Make this terminal active on start of @code{greetd}.
18650 @item @code{default-session-user} (default: @samp{"greeter"})
18651 The user to use for running the greeter.
18653 @item @code{default-session-command} (default: @code{(greetd-agreety-session)})
18654 Can be either instance of @code{greetd-agreety-session} configuration or
18655 @code{gexp->script} like object to use as greeter.
18660 @deftp {Data Type} greetd-agreety-session
18661 Configuration record for the agreety greetd greeter.
18664 @item @code{agreety} (default: @code{greetd})
18665 The package with @command{/bin/agreety} command.
18667 @item @code{command} (default: @code{(file-append bash "/bin/bash")})
18668 Command to be started by @command{/bin/agreety} on successful login.
18670 @item @code{command-args} (default: @code{'("-l")})
18671 Command arguments to pass to command.
18673 @item @code{extra-env} (default: @code{'()})
18674 Extra environment variables to set on login.
18676 @item @code{xdg-env?} (default: @code{#t})
18677 If true @code{XDG_RUNTIME_DIR} and @code{XDG_SESSION_TYPE} will be set
18678 before starting command. One should note that, @code{extra-env} variables
18679 are set right after mentioned variables, so that they can be overriden.
18684 @deftp {Data Type} greetd-wlgreet-session
18685 Generic configuration record for the wlgreet greetd greeter.
18688 @item @code{wlgreet} (default: @code{wlgreet})
18689 The package with the @command{/bin/wlgreet} command.
18691 @item @code{command} (default: @code{(file-append sway "/bin/sway")})
18692 Command to be started by @command{/bin/wlgreet} on successful login.
18694 @item @code{command-args} (default: @code{'()})
18695 Command arguments to pass to command.
18697 @item @code{output-mode} (default: @code{"all"})
18698 Option to use for @code{outputMode} in the TOML configuration file.
18700 @item @code{scale} (default: @code{1})
18701 Option to use for @code{scale} in the TOML configuration file.
18703 @item @code{background} (default: @code{'(0 0 0 0.9)})
18704 RGBA list to use as the background colour of the login prompt.
18706 @item @code{headline} (default: @code{'(1 1 1 1)})
18707 RGBA list to use as the headline colour of the UI popup.
18709 @item @code{prompt} (default: @code{'(1 1 1 1)})
18710 RGBA list to use as the prompt colour of the UI popup.
18712 @item @code{prompt-error} (default: @code{'(1 1 1 1)})
18713 RGBA list to use as the error colour of the UI popup.
18715 @item @code{border} (default: @code{'(1 1 1 1)})
18716 RGBA list to use as the border colour of the UI popup.
18718 @item @code{extra-env} (default: @code{'()})
18719 Extra environment variables to set on login.
18724 @deftp {Data Type} greetd-wlgreet-sway-session
18725 Sway-specific configuration record for the wlgreet greetd greeter.
18728 @item @code{wlgreet-session} (default: @code{(greetd-wlgreet-session)})
18729 A @code{greetd-wlgreet-session} record for generic wlgreet configuration,
18730 on top of the Sway-specific @code{greetd-wlgreet-sway-session}.
18732 @item @code{sway} (default: @code{sway})
18733 The package providing the @command{/bin/sway} command.
18735 @item @code{sway-configuration} (default: #f)
18736 File-like object providing an additional Sway configuration file to be
18737 prepended to the mandatory part of the configuration.
18741 Here is an example of a greetd configuration that uses wlgreet and Sway:
18744 (greetd-configuration
18745 ;; We need to give the greeter user these permissions, otherwise
18746 ;; Sway will crash on launch.
18747 (greeter-supplementary-groups (list "video" "input" "seat"))
18749 (list (greetd-terminal-configuration
18751 (terminal-switch #t)
18752 (default-session-command
18753 (greetd-wlgreet-sway-session
18754 (sway-configuration
18755 (local-file "sway-greetd.conf"))))))))
18759 @node Scheduled Job Execution
18760 @subsection Scheduled Job Execution
18764 @cindex scheduling jobs
18765 The @code{(gnu services mcron)} module provides an interface to
18766 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
18767 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
18768 Unix @command{cron} daemon; the main difference is that it is
18769 implemented in Guile Scheme, which provides a lot of flexibility when
18770 specifying the scheduling of jobs and their actions.
18772 The example below defines an operating system that runs the
18773 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
18774 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
18775 well as the @command{mkid} command on behalf of an unprivileged user
18776 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
18777 gexps to introduce job definitions that are passed to mcron
18778 (@pxref{G-Expressions}).
18781 (use-modules (guix) (gnu) (gnu services mcron))
18782 (use-package-modules base idutils)
18784 (define updatedb-job
18785 ;; Run 'updatedb' at 3AM every day. Here we write the
18786 ;; job's action as a Scheme procedure.
18787 #~(job '(next-hour '(3))
18789 (execl (string-append #$findutils "/bin/updatedb")
18791 "--prunepaths=/tmp /var/tmp /gnu/store"))
18794 (define garbage-collector-job
18795 ;; Collect garbage 5 minutes after midnight every day.
18796 ;; The job's action is a shell command.
18797 #~(job "5 0 * * *" ;Vixie cron syntax
18800 (define idutils-job
18801 ;; Update the index database as user "charlie" at 12:15PM
18802 ;; and 19:15PM. This runs from the user's home directory.
18803 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
18804 (string-append #$idutils "/bin/mkid src")
18810 ;; %BASE-SERVICES already includes an instance of
18811 ;; 'mcron-service-type', which we extend with additional
18812 ;; jobs using 'simple-service'.
18813 (services (cons (simple-service 'my-cron-jobs
18815 (list garbage-collector-job
18822 When providing the action of a job specification as a procedure, you
18823 should provide an explicit name for the job via the optional 3rd
18824 argument as done in the @code{updatedb-job} example above. Otherwise,
18825 the job would appear as ``Lambda function'' in the output of
18826 @command{herd schedule mcron}, which is not nearly descriptive enough!
18829 For more complex jobs defined in Scheme where you need control over the top
18830 level, for instance to introduce a @code{use-modules} form, you can move your
18831 code to a separate program using the @code{program-file} procedure of the
18832 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
18836 (define %battery-alert-job
18837 ;; Beep when the battery percentage falls below %MIN-LEVEL.
18839 '(next-minute (range 0 60 1))
18841 "battery-alert.scm"
18842 (with-imported-modules (source-module-closure
18843 '((guix build utils)))
18845 (use-modules (guix build utils)
18848 (ice-9 textual-ports)
18851 (define %min-level 20)
18853 (setenv "LC_ALL" "C") ;ensure English output
18854 (and-let* ((input-pipe (open-pipe*
18856 #$(file-append acpi "/bin/acpi")))
18857 (output (get-string-all input-pipe))
18858 (m (string-match "Discharging, ([0-9]+)%" output))
18859 (level (string->number (match:substring m 1)))
18860 ((< level %min-level)))
18861 (format #t "warning: Battery level is low (~a%)~%" level)
18862 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
18865 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
18866 for more information on mcron job specifications. Below is the
18867 reference of the mcron service.
18869 On a running system, you can use the @code{schedule} action of the service to
18870 visualize the mcron jobs that will be executed next:
18873 # herd schedule mcron
18877 The example above lists the next five tasks that will be executed, but you can
18878 also specify the number of tasks to display:
18881 # herd schedule mcron 10
18884 @defvr {Scheme Variable} mcron-service-type
18885 This is the type of the @code{mcron} service, whose value is an
18886 @code{mcron-configuration} object.
18888 This service type can be the target of a service extension that provides
18889 additional job specifications (@pxref{Service Composition}). In other
18890 words, it is possible to define services that provide additional mcron
18894 @deftp {Data Type} mcron-configuration
18895 Data type representing the configuration of mcron.
18898 @item @code{mcron} (default: @var{mcron})
18899 The mcron package to use.
18902 This is a list of gexps (@pxref{G-Expressions}), where each gexp
18903 corresponds to an mcron job specification (@pxref{Syntax, mcron job
18904 specifications,, mcron, GNU@tie{}mcron}).
18910 @subsection Log Rotation
18913 @cindex log rotation
18915 Log files such as those found in @file{/var/log} tend to grow endlessly,
18916 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
18917 their contents in separate files, possibly compressed. The @code{(gnu
18918 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
18919 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
18921 This service is part of @code{%base-services}, and thus enabled by
18922 default, with the default settings, for commonly encountered log files.
18923 The example below shows how to extend it with an additional
18924 @dfn{rotation}, should you need to do that (usually, services that
18925 produce log files already take care of that):
18928 (use-modules (guix) (gnu))
18929 (use-service-modules admin)
18931 (define my-log-files
18932 ;; Log files that I want to rotate.
18933 '("/var/log/something.log" "/var/log/another.log"))
18937 (services (cons (simple-service 'rotate-my-stuff
18938 rottlog-service-type
18939 (list (log-rotation
18941 (files my-log-files))))
18945 @defvr {Scheme Variable} rottlog-service-type
18946 This is the type of the Rottlog service, whose value is a
18947 @code{rottlog-configuration} object.
18949 Other services can extend this one with new @code{log-rotation} objects
18950 (see below), thereby augmenting the set of files to be rotated.
18952 This service type can define mcron jobs (@pxref{Scheduled Job
18953 Execution}) to run the rottlog service.
18956 @deftp {Data Type} rottlog-configuration
18957 Data type representing the configuration of rottlog.
18960 @item @code{rottlog} (default: @code{rottlog})
18961 The Rottlog package to use.
18963 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
18964 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
18965 rottlog, GNU Rot[t]log Manual}).
18967 @item @code{rotations} (default: @code{%default-rotations})
18968 A list of @code{log-rotation} objects as defined below.
18971 This is a list of gexps where each gexp corresponds to an mcron job
18972 specification (@pxref{Scheduled Job Execution}).
18976 @deftp {Data Type} log-rotation
18977 Data type representing the rotation of a group of log files.
18979 Taking an example from the Rottlog manual (@pxref{Period Related File
18980 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
18986 (files '("/var/log/apache/*"))
18987 (options '("storedir apache-archives"
18993 The list of fields is as follows:
18996 @item @code{frequency} (default: @code{'weekly})
18997 The log rotation frequency, a symbol.
19000 The list of files or file glob patterns to rotate.
19002 @vindex %default-log-rotation-options
19003 @item @code{options} (default: @code{%default-log-rotation-options})
19004 The list of rottlog options for this rotation (@pxref{Configuration
19005 parameters,,, rottlog, GNU Rot[t]log Manual}).
19007 @item @code{post-rotate} (default: @code{#f})
19008 Either @code{#f} or a gexp to execute once the rotation has completed.
19012 @defvr {Scheme Variable} %default-rotations
19013 Specifies weekly rotation of @code{%rotated-files} and of
19014 @file{/var/log/guix-daemon.log}.
19017 @defvr {Scheme Variable} %rotated-files
19018 The list of syslog-controlled files to be rotated. By default it is:
19019 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
19020 "/var/log/maillog")}.
19023 Some log files just need to be deleted periodically once they are old,
19024 without any other criterion and without any archival step. This is the
19025 case of build logs stored by @command{guix-daemon} under
19026 @file{/var/log/guix/drvs} (@pxref{Invoking guix-daemon}). The
19027 @code{log-cleanup} service addresses this use case. For example,
19028 @code{%base-services} (@pxref{Base Services}) includes the following:
19031 ;; Periodically delete old build logs.
19032 (service log-cleanup-service-type
19033 (log-cleanup-configuration
19034 (directory "/var/log/guix/drvs")))
19037 That ensures build logs do not accumulate endlessly.
19039 @defvr {Scheme Variable} log-cleanup-service-type
19040 This is the type of the service to delete old logs. Its value must be a
19041 @code{log-cleanup-configuration} record as described below.
19044 @deftp {Data Type} log-cleanup-configuration
19045 Data type representing the log cleanup configuration
19048 @item @code{directory}
19049 Name of the directory containing log files.
19051 @item @code{expiry} (default: @code{(* 6 30 24 3600)})
19052 Age in seconds after which a file is subject to deletion (six months by
19055 @item @code{schedule} (default: @code{"30 12 01,08,15,22 * *"})
19056 String or gexp denoting the corresponding mcron job schedule
19057 (@pxref{Scheduled Job Execution}).
19061 @cindex logging, anonymization
19062 @subheading Anonip Service
19064 Anonip is a privacy filter that removes IP address from web server logs.
19065 This service creates a FIFO and filters any written lines with anonip
19066 before writing the filtered log to a target file.
19068 The following example sets up the FIFO
19069 @file{/var/run/anonip/https.access.log} and writes the filtered log file
19070 @file{/var/log/anonip/https.access.log}.
19073 (service anonip-service-type
19074 (anonip-configuration
19075 (input "/var/run/anonip/https.access.log")
19076 (output "/var/log/anonip/https.access.log")))
19079 Configure your web server to write its logs to the FIFO at
19080 @file{/var/run/anonip/https.access.log} and collect the anonymized log
19081 file at @file{/var/web-logs/https.access.log}.
19083 @deftp {Data Type} anonip-configuration
19084 This data type represents the configuration of anonip.
19085 It has the following parameters:
19088 @item @code{anonip} (default: @code{anonip})
19089 The anonip package to use.
19092 The file name of the input log file to process. The service creates a
19093 FIFO of this name. The web server should write its logs to this FIFO.
19095 @item @code{output}
19096 The file name of the processed log file.
19099 The following optional settings may be provided:
19102 @item @code{skip-private?}
19103 When @code{#true} do not mask addresses in private ranges.
19105 @item @code{column}
19106 A 1-based indexed column number. Assume IP address is in the specified
19107 column (default is 1).
19109 @item @code{replacement}
19110 Replacement string in case address parsing fails, e.g. @code{"0.0.0.0"}.
19112 @item @code{ipv4mask}
19113 Number of bits to mask in IPv4 addresses.
19115 @item @code{ipv6mask}
19116 Number of bits to mask in IPv6 addresses.
19118 @item @code{increment}
19119 Increment the IP address by the given number. By default this is zero.
19121 @item @code{delimiter}
19122 Log delimiter string.
19125 Regular expression for detecting IP addresses. Use this instead of @code{column}.
19130 @node Networking Setup
19131 @subsection Networking Setup
19133 The @code{(gnu services networking)} module provides services to
19134 configure network interfaces and set up networking on your machine.
19135 Those services provide different ways for you to set up your machine: by
19136 declaring a static network configuration, by running a Dynamic Host
19137 Configuration Protocol (DHCP) client, or by running daemons such as
19138 NetworkManager and Connman that automate the whole process,
19139 automatically adapt to connectivity changes, and provide a high-level
19142 On a laptop, NetworkManager and Connman are by far the most convenient
19143 options, which is why the default desktop services include
19144 NetworkManager (@pxref{Desktop Services, @code{%desktop-services}}).
19145 For a server, or for a virtual machine or a container, static network
19146 configuration or a simple DHCP client are often more appropriate.
19148 This section describes the various network setup services available,
19149 starting with static network configuration.
19151 @defvr {Scheme Variable} static-networking-service-type
19152 This is the type for statically-configured network interfaces. Its
19153 value must be a list of @code{static-networking} records. Each of them
19154 declares a set of @dfn{addresses}, @dfn{routes}, and @dfn{links}, as
19157 @cindex network interface controller (NIC)
19158 @cindex NIC, networking interface controller
19159 Here is the simplest configuration, with only one network interface
19160 controller (NIC) and only IPv4 connectivity:
19163 ;; Static networking for one NIC, IPv4-only.
19164 (service static-networking-service-type
19165 (list (static-networking
19167 (list (network-address
19169 (value "10.0.2.15/24"))))
19171 (list (network-route
19172 (destination "default")
19173 (gateway "10.0.2.2"))))
19174 (name-servers '("10.0.2.3")))))
19177 The snippet above can be added to the @code{services} field of your
19178 operating system configuration (@pxref{Using the Configuration System}).
19179 It will configure your machine to have 10.0.2.15 as its IP address, with
19180 a 24-bit netmask for the local network---meaning that any 10.0.2.@var{x}
19181 address is on the local area network (LAN). Traffic to addresses
19182 outside the local network is routed @i{via} 10.0.2.2. Host names are
19183 resolved by sending domain name system (DNS) queries to 10.0.2.3.
19186 @deftp {Data Type} static-networking
19187 This is the data type representing a static network configuration.
19189 As an example, here is how you would declare the configuration of a
19190 machine with a single network interface controller (NIC) available as
19191 @code{eno1}, and with one IPv4 and one IPv6 address:
19194 ;; Network configuration for one NIC, IPv4 + IPv6.
19196 (addresses (list (network-address
19198 (value "10.0.2.15/24"))
19201 (value "2001:123:4567:101::1/64"))))
19202 (routes (list (network-route
19203 (destination "default")
19204 (gateway "10.0.2.2"))
19206 (destination "default")
19207 (gateway "2020:321:4567:42::1"))))
19208 (name-servers '("10.0.2.3")))
19211 If you are familiar with the @command{ip} command of the
19212 @uref{https://wiki.linuxfoundation.org/networking/iproute2,
19213 @code{iproute2} package} found on Linux-based systems, the declaration
19214 above is equivalent to typing:
19217 ip address add 10.0.2.15/24 dev eno1
19218 ip address add 2001:123:4567:101::1/64 dev eno1
19219 ip route add default via inet 10.0.2.2
19220 ip route add default via inet6 2020:321:4567:42::1
19223 Run @command{man 8 ip} for more info. Venerable GNU/Linux users will
19224 certainly know how to do it with @command{ifconfig} and @command{route},
19225 but we'll spare you that.
19227 The available fields of this data type are as follows:
19230 @item @code{addresses}
19231 @itemx @code{links} (default: @code{'()})
19232 @itemx @code{routes} (default: @code{'()})
19233 The list of @code{network-address}, @code{network-link}, and
19234 @code{network-route} records for this network (see below).
19236 @item @code{name-servers} (default: @code{'()})
19237 The list of IP addresses (strings) of domain name servers. These IP
19238 addresses go to @file{/etc/resolv.conf}.
19240 @item @code{provision} (default: @code{'(networking)})
19241 If true, this should be a list of symbols for the Shepherd service
19242 corresponding to this network configuration.
19244 @item @code{requirement} (default @code{'()})
19245 The list of Shepherd services depended on.
19249 @deftp {Data Type} network-address
19250 This is the data type representing the IP address of a network
19255 The name of the network interface for this address---e.g.,
19259 The actual IP address and network mask, in
19260 @uref{https://en.wikipedia.org/wiki/CIDR#CIDR_notation, @acronym{CIDR,
19261 Classless Inter-Domain Routing} notation}, as a string.
19263 For example, @code{"10.0.2.15/24"} denotes IPv4 address 10.0.2.15 on a
19264 24-bit sub-network---all 10.0.2.@var{x} addresses are on the same local
19268 Whether @code{value} denotes an IPv6 address. By default this is
19269 automatically determined.
19273 @deftp {Data Type} network-route
19274 This is the data type representing a network route.
19277 @item @code{destination}
19278 The route destination (a string), either an IP address and network mask
19279 or @code{"default"} to denote the default route.
19281 @item @code{source} (default: @code{#f})
19284 @item @code{device} (default: @code{#f})
19285 The device used for this route---e.g., @code{"eno2"}.
19287 @item @code{ipv6?} (default: auto)
19288 Whether this is an IPv6 route. By default this is automatically
19289 determined based on @code{destination} or @code{gateway}.
19291 @item @code{gateway} (default: @code{#f})
19292 IP address (a string) through which traffic is routed.
19296 @deftp {Data Type} network-link
19297 Data type for a network link (@pxref{Link,,, guile-netlink,
19298 Guile-Netlink Manual}).
19302 The name of the link---e.g., @code{"v0p0"}.
19305 A symbol denoting the type of the link---e.g., @code{'veth}.
19308 List of arguments for this type of link.
19312 @cindex loopback device
19313 @defvr {Scheme Variable} %loopback-static-networking
19314 This is the @code{static-networking} record representing the ``loopback
19315 device'', @code{lo}, for IP addresses 127.0.0.1 and ::1, and providing
19316 the @code{loopback} Shepherd service.
19319 @cindex networking, with QEMU
19320 @cindex QEMU, networking
19321 @defvr {Scheme Variable} %qemu-static-networking
19322 This is the @code{static-networking} record representing network setup
19323 when using QEMU's user-mode network stack on @code{eth0} (@pxref{Using
19324 the user mode network stack,,, QEMU, QEMU Documentation}).
19327 @cindex DHCP, networking service
19328 @defvr {Scheme Variable} dhcp-client-service-type
19329 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
19330 Protocol (DHCP) client.
19333 @deftp {Data Type} dhcp-client-configuration
19334 Data type representing the configuration of the DHCP client service.
19337 @item @code{package} (default: @code{isc-dhcp})
19338 DHCP client package to use.
19340 @item @code{interfaces} (default: @code{'all})
19341 Either @code{'all} or the list of interface names that the DHCP client
19342 should listen on---e.g., @code{'("eno1")}.
19344 When set to @code{'all}, the DHCP client listens on all the available
19345 non-loopback interfaces that can be activated. Otherwise the DHCP
19346 client listens only on the specified interfaces.
19350 @cindex NetworkManager
19352 @defvr {Scheme Variable} network-manager-service-type
19353 This is the service type for the
19354 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
19355 service. The value for this service type is a
19356 @code{network-manager-configuration} record.
19358 This service is part of @code{%desktop-services} (@pxref{Desktop
19362 @deftp {Data Type} network-manager-configuration
19363 Data type representing the configuration of NetworkManager.
19366 @item @code{network-manager} (default: @code{network-manager})
19367 The NetworkManager package to use.
19369 @item @code{dns} (default: @code{"default"})
19370 Processing mode for DNS, which affects how NetworkManager uses the
19371 @code{resolv.conf} configuration file.
19375 NetworkManager will update @code{resolv.conf} to reflect the nameservers
19376 provided by currently active connections.
19379 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
19380 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
19381 then update @code{resolv.conf} to point to the local nameserver.
19383 With this setting, you can share your network connection. For example when
19384 you want to share your network connection to another laptop @i{via} an
19385 Ethernet cable, you can open @command{nm-connection-editor} and configure the
19386 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
19387 and reestablish the connection (or reboot).
19389 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
19390 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
19391 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
19392 browser on your host system, or connect to the VM @i{via} SSH
19393 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
19394 host-to-guest connection, run this command once:
19397 nmcli connection add type tun \
19398 connection.interface-name tap0 \
19399 tun.mode tap tun.owner $(id -u) \
19400 ipv4.method shared \
19401 ipv4.addresses 172.28.112.1/24
19404 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
19405 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
19406 @command{qemu-system-...}.
19409 NetworkManager will not modify @code{resolv.conf}.
19412 @item @code{vpn-plugins} (default: @code{'()})
19413 This is the list of available plugins for virtual private networks
19414 (VPNs). An example of this is the @code{network-manager-openvpn}
19415 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
19421 @deffn {Scheme Variable} connman-service-type
19422 This is the service type to run @url{https://01.org/connman,Connman},
19423 a network connection manager.
19425 Its value must be an
19426 @code{connman-configuration} record as in this example:
19429 (service connman-service-type
19430 (connman-configuration
19431 (disable-vpn? #t)))
19434 See below for details about @code{connman-configuration}.
19437 @deftp {Data Type} connman-configuration
19438 Data Type representing the configuration of connman.
19441 @item @code{connman} (default: @var{connman})
19442 The connman package to use.
19444 @item @code{disable-vpn?} (default: @code{#f})
19445 When true, disable connman's vpn plugin.
19449 @cindex WPA Supplicant
19450 @defvr {Scheme Variable} wpa-supplicant-service-type
19451 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
19452 supplicant}, an authentication daemon required to authenticate against
19453 encrypted WiFi or ethernet networks.
19456 @deftp {Data Type} wpa-supplicant-configuration
19457 Data type representing the configuration of WPA Supplicant.
19459 It takes the following parameters:
19462 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
19463 The WPA Supplicant package to use.
19465 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
19466 List of services that should be started before WPA Supplicant starts.
19468 @item @code{dbus?} (default: @code{#t})
19469 Whether to listen for requests on D-Bus.
19471 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
19472 Where to store the PID file.
19474 @item @code{interface} (default: @code{#f})
19475 If this is set, it must specify the name of a network interface that
19476 WPA supplicant will control.
19478 @item @code{config-file} (default: @code{#f})
19479 Optional configuration file to use.
19481 @item @code{extra-options} (default: @code{'()})
19482 List of additional command-line arguments to pass to the daemon.
19486 @cindex ModemManager
19487 Some networking devices such as modems require special care, and this is
19488 what the services below focus on.
19490 @defvr {Scheme Variable} modem-manager-service-type
19491 This is the service type for the
19492 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
19493 service. The value for this service type is a
19494 @code{modem-manager-configuration} record.
19496 This service is part of @code{%desktop-services} (@pxref{Desktop
19500 @deftp {Data Type} modem-manager-configuration
19501 Data type representing the configuration of ModemManager.
19504 @item @code{modem-manager} (default: @code{modem-manager})
19505 The ModemManager package to use.
19510 @cindex USB_ModeSwitch
19511 @cindex Modeswitching
19513 @defvr {Scheme Variable} usb-modeswitch-service-type
19514 This is the service type for the
19515 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
19516 service. The value for this service type is
19517 a @code{usb-modeswitch-configuration} record.
19519 When plugged in, some USB modems (and other USB devices) initially present
19520 themselves as a read-only storage medium and not as a modem. They need to be
19521 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
19522 installs udev rules to automatically modeswitch these devices when they are
19525 This service is part of @code{%desktop-services} (@pxref{Desktop
19529 @deftp {Data Type} usb-modeswitch-configuration
19530 Data type representing the configuration of USB_ModeSwitch.
19533 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
19534 The USB_ModeSwitch package providing the binaries for modeswitching.
19536 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
19537 The package providing the device data and udev rules file used by
19540 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
19541 Which config file to use for the USB_ModeSwitch dispatcher. By default the
19542 config file shipped with USB_ModeSwitch is used which disables logging to
19543 @file{/var/log} among other default settings. If set to @code{#f}, no config
19550 @node Networking Services
19551 @subsection Networking Services
19553 The @code{(gnu services networking)} module discussed in the previous
19554 section provides services for more advanced setups: providing a DHCP
19555 service for others to use, filtering packets with iptables or nftables,
19556 running a WiFi access point with @command{hostapd}, running the
19557 @command{inetd} ``superdaemon'', and more. This section describes
19560 @deffn {Scheme Procedure} dhcpd-service-type
19561 This type defines a service that runs a DHCP daemon. To create a
19562 service of this type, you must supply a @code{<dhcpd-configuration>}.
19566 (service dhcpd-service-type
19567 (dhcpd-configuration
19568 (config-file (local-file "my-dhcpd.conf"))
19569 (interfaces '("enp0s25"))))
19573 @deftp {Data Type} dhcpd-configuration
19575 @item @code{package} (default: @code{isc-dhcp})
19576 The package that provides the DHCP daemon. This package is expected to
19577 provide the daemon at @file{sbin/dhcpd} relative to its output
19578 directory. The default package is the
19579 @uref{https://www.isc.org/dhcp/, ISC's DHCP server}.
19580 @item @code{config-file} (default: @code{#f})
19581 The configuration file to use. This is required. It will be passed to
19582 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
19583 object (@pxref{G-Expressions, file-like objects}). See @code{man
19584 dhcpd.conf} for details on the configuration file syntax.
19585 @item @code{version} (default: @code{"4"})
19586 The DHCP version to use. The ISC DHCP server supports the values ``4'',
19587 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
19588 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
19590 @item @code{run-directory} (default: @code{"/run/dhcpd"})
19591 The run directory to use. At service activation time, this directory
19592 will be created if it does not exist.
19593 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
19594 The PID file to use. This corresponds to the @code{-pf} option of
19595 @code{dhcpd}. See @code{man dhcpd} for details.
19596 @item @code{interfaces} (default: @code{'()})
19597 The names of the network interfaces on which dhcpd should listen for
19598 broadcasts. If this list is not empty, then its elements (which must be
19599 strings) will be appended to the @code{dhcpd} invocation when starting
19600 the daemon. It may not be necessary to explicitly specify any
19601 interfaces here; see @code{man dhcpd} for details.
19605 @cindex hostapd service, for Wi-Fi access points
19606 @cindex Wi-Fi access points, hostapd service
19607 @defvr {Scheme Variable} hostapd-service-type
19608 This is the service type to run the @uref{https://w1.fi/hostapd/,
19609 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
19610 authentication servers. Its associated value must be a
19611 @code{hostapd-configuration} as shown below:
19614 ;; Use wlan1 to run the access point for "My Network".
19615 (service hostapd-service-type
19616 (hostapd-configuration
19617 (interface "wlan1")
19618 (ssid "My Network")
19623 @deftp {Data Type} hostapd-configuration
19624 This data type represents the configuration of the hostapd service, with
19625 the following fields:
19628 @item @code{package} (default: @code{hostapd})
19629 The hostapd package to use.
19631 @item @code{interface} (default: @code{"wlan0"})
19632 The network interface to run the WiFi access point.
19635 The SSID (@dfn{service set identifier}), a string that identifies this
19638 @item @code{broadcast-ssid?} (default: @code{#t})
19639 Whether to broadcast this SSID.
19641 @item @code{channel} (default: @code{1})
19642 The WiFi channel to use.
19644 @item @code{driver} (default: @code{"nl80211"})
19645 The driver interface type. @code{"nl80211"} is used with all Linux
19646 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
19647 RADIUS server that does # not control any wireless/wired driver.
19649 @item @code{extra-settings} (default: @code{""})
19650 Extra settings to append as-is to the hostapd configuration file. See
19651 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
19652 configuration file reference.
19656 @defvr {Scheme Variable} simulated-wifi-service-type
19657 This is the type of a service to simulate WiFi networking, which can be
19658 useful in virtual machines for testing purposes. The service loads the
19660 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
19661 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
19662 network that can be seen on @code{wlan0}, by default.
19664 The service's value is a @code{hostapd-configuration} record.
19669 @defvr {Scheme Variable} iptables-service-type
19670 This is the service type to set up an iptables configuration. iptables is a
19671 packet filtering framework supported by the Linux kernel. This service
19672 supports configuring iptables for both IPv4 and IPv6. A simple example
19673 configuration rejecting all incoming connections except those to the ssh port
19677 (service iptables-service-type
19678 (iptables-configuration
19679 (ipv4-rules (plain-file "iptables.rules" "*filter
19683 -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
19684 -A INPUT -p tcp --dport 22 -j ACCEPT
19685 -A INPUT -j REJECT --reject-with icmp-port-unreachable
19688 (ipv6-rules (plain-file "ip6tables.rules" "*filter
19692 -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
19693 -A INPUT -p tcp --dport 22 -j ACCEPT
19694 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
19700 @deftp {Data Type} iptables-configuration
19701 The data type representing the configuration of iptables.
19704 @item @code{iptables} (default: @code{iptables})
19705 The iptables package that provides @code{iptables-restore} and
19706 @code{ip6tables-restore}.
19707 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
19708 The iptables rules to use. It will be passed to @code{iptables-restore}.
19709 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
19711 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
19712 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
19713 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
19719 @defvr {Scheme Variable} nftables-service-type
19720 This is the service type to set up a nftables configuration. nftables is a
19721 netfilter project that aims to replace the existing iptables, ip6tables,
19722 arptables and ebtables framework. It provides a new packet filtering
19723 framework, a new user-space utility @command{nft}, and a compatibility layer
19724 for iptables. This service comes with a default ruleset
19725 @code{%default-nftables-ruleset} that rejecting all incoming connections
19726 except those to the ssh port 22. To use it, simply write:
19729 (service nftables-service-type)
19733 @deftp {Data Type} nftables-configuration
19734 The data type representing the configuration of nftables.
19737 @item @code{package} (default: @code{nftables})
19738 The nftables package that provides @command{nft}.
19739 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
19740 The nftables ruleset to use. This may be any ``file-like'' object
19741 (@pxref{G-Expressions, file-like objects}).
19745 @cindex NTP (Network Time Protocol), service
19746 @cindex ntpd, service for the Network Time Protocol daemon
19747 @cindex real time clock
19748 @defvr {Scheme Variable} ntp-service-type
19749 This is the type of the service running the @uref{https://www.ntp.org,
19750 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
19751 system clock synchronized with that of the specified NTP servers.
19753 The value of this service is an @code{ntpd-configuration} object, as described
19757 @deftp {Data Type} ntp-configuration
19758 This is the data type for the NTP service configuration.
19761 @item @code{servers} (default: @code{%ntp-servers})
19762 This is the list of servers (@code{<ntp-server>} records) with which
19763 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
19766 @item @code{allow-large-adjustment?} (default: @code{#t})
19767 This determines whether @command{ntpd} is allowed to make an initial
19768 adjustment of more than 1,000 seconds.
19770 @item @code{ntp} (default: @code{ntp})
19771 The NTP package to use.
19775 @defvr {Scheme Variable} %ntp-servers
19776 List of host names used as the default NTP servers. These are servers of the
19777 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
19780 @deftp {Data Type} ntp-server
19781 The data type representing the configuration of a NTP server.
19784 @item @code{type} (default: @code{'server})
19785 The type of the NTP server, given as a symbol. One of @code{'pool},
19786 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
19788 @item @code{address}
19789 The address of the server, as a string.
19791 @item @code{options}
19792 NTPD options to use with that specific server, given as a list of option names
19793 and/or of option names and values tuples. The following example define a server
19794 to use with the options @option{iburst} and @option{prefer}, as well as
19795 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
19800 (address "some.ntp.server.org")
19801 (options `(iburst (version 3) (maxpoll 16) prefer))))
19807 @deffn {Scheme Procedure} openntpd-service-type
19808 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
19809 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
19810 clock synchronized with that of the given servers.
19814 openntpd-service-type
19815 (openntpd-configuration
19816 (listen-on '("127.0.0.1" "::1"))
19817 (sensor '("udcf0 correction 70000"))
19818 (constraint-from '("www.gnu.org"))
19819 (constraints-from '("https://www.google.com/"))))
19824 @defvr {Scheme Variable} %openntpd-servers
19825 This variable is a list of the server addresses defined in
19826 @code{%ntp-servers}.
19829 @deftp {Data Type} openntpd-configuration
19831 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
19832 The openntpd executable to use.
19833 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
19834 A list of local IP addresses or hostnames the ntpd daemon should listen on.
19835 @item @code{query-from} (default: @code{'()})
19836 A list of local IP address the ntpd daemon should use for outgoing queries.
19837 @item @code{sensor} (default: @code{'()})
19838 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
19839 will listen to each sensor that actually exists and ignore non-existent ones.
19840 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
19842 @item @code{server} (default: @code{'()})
19843 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
19844 @item @code{servers} (default: @code{%openntp-servers})
19845 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
19846 @item @code{constraint-from} (default: @code{'()})
19847 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
19848 This time information is not used for precision but acts as an authenticated
19849 constraint, thereby reducing the impact of unauthenticated NTP
19850 man-in-the-middle attacks.
19851 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
19853 @item @code{constraints-from} (default: @code{'()})
19854 As with constraint from, specify a list of URLs, IP addresses or hostnames of
19855 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
19856 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
19861 @deffn {Scheme variable} inetd-service-type
19862 This service runs the @command{inetd} (@pxref{inetd invocation,,,
19863 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
19864 connections on internet sockets, and lazily starts the specified server
19865 program when a connection is made on one of these sockets.
19867 The value of this service is an @code{inetd-configuration} object. The
19868 following example configures the @command{inetd} daemon to provide the
19869 built-in @command{echo} service, as well as an smtp service which
19870 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
19871 gateway @code{hostname}:
19876 (inetd-configuration
19880 (socket-type 'stream)
19887 (socket-type 'stream)
19891 (program (file-append openssh "/bin/ssh"))
19893 '("ssh" "-qT" "-i" "/path/to/ssh_key"
19894 "-W" "smtp-server:25" "user@@hostname")))))))
19897 See below for more details about @code{inetd-configuration}.
19900 @deftp {Data Type} inetd-configuration
19901 Data type representing the configuration of @command{inetd}.
19904 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
19905 The @command{inetd} executable to use.
19907 @item @code{entries} (default: @code{'()})
19908 A list of @command{inetd} service entries. Each entry should be created
19909 by the @code{inetd-entry} constructor.
19913 @deftp {Data Type} inetd-entry
19914 Data type representing an entry in the @command{inetd} configuration.
19915 Each entry corresponds to a socket where @command{inetd} will listen for
19919 @item @code{node} (default: @code{#f})
19920 Optional string, a comma-separated list of local addresses
19921 @command{inetd} should use when listening for this service.
19922 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
19923 description of all options.
19925 A string, the name must correspond to an entry in @code{/etc/services}.
19926 @item @code{socket-type}
19927 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
19929 @item @code{protocol}
19930 A string, must correspond to an entry in @code{/etc/protocols}.
19931 @item @code{wait?} (default: @code{#t})
19932 Whether @command{inetd} should wait for the server to exit before
19933 listening to new service requests.
19935 A string containing the user (and, optionally, group) name of the user
19936 as whom the server should run. The group name can be specified in a
19937 suffix, separated by a colon or period, i.e.@: @code{"user"},
19938 @code{"user:group"} or @code{"user.group"}.
19939 @item @code{program} (default: @code{"internal"})
19940 The server program which will serve the requests, or @code{"internal"}
19941 if @command{inetd} should use a built-in service.
19942 @item @code{arguments} (default: @code{'()})
19943 A list strings or file-like objects, which are the server program's
19944 arguments, starting with the zeroth argument, i.e.@: the name of the
19945 program itself. For @command{inetd}'s internal services, this entry
19946 must be @code{'()} or @code{'("internal")}.
19949 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
19950 detailed discussion of each configuration field.
19953 @cindex opendht, distributed hash table network service
19954 @cindex dhtproxy, for use with jami
19955 @defvr {Scheme Variable} opendht-service-type
19956 This is the type of the service running a @uref{https://opendht.net,
19957 OpenDHT} node, @command{dhtnode}. The daemon can be used to host your
19958 own proxy service to the distributed hash table (DHT), for example to
19959 connect to with Jami, among other applications.
19961 @quotation Important
19962 When using the OpenDHT proxy server, the IP addresses it ``sees'' from
19963 the clients should be addresses reachable from other peers. In practice
19964 this means that a publicly reachable address is best suited for a proxy
19965 server, outside of your private network. For example, hosting the proxy
19966 server on a IPv4 private local network and exposing it via port
19967 forwarding could work for external peers, but peers local to the proxy
19968 would have their private addresses shared with the external peers,
19969 leading to connectivity problems.
19972 The value of this service is a @code{opendht-configuration} object, as
19976 @c The fields documentation has been auto-generated using the
19977 @c configuration->documentation procedure from
19978 @c (gnu services configuration).
19979 @deftp {Data Type} opendht-configuration
19980 Available @code{opendht-configuration} fields are:
19983 @item @code{opendht} (default: @code{opendht}) (type: file-like)
19984 The @code{opendht} package to use.
19986 @item @code{peer-discovery?} (default: @code{#f}) (type: boolean)
19987 Whether to enable the multicast local peer discovery mechanism.
19989 @item @code{enable-logging?} (default: @code{#f}) (type: boolean)
19990 Whether to enable logging messages to syslog. It is disabled by default
19991 as it is rather verbose.
19993 @item @code{debug?} (default: @code{#f}) (type: boolean)
19994 Whether to enable debug-level logging messages. This has no effect if
19995 logging is disabled.
19997 @item @code{bootstrap-host} (default: @code{"bootstrap.jami.net:4222"}) (type: maybe-string)
19998 The node host name that is used to make the first connection to the
19999 network. A specific port value can be provided by appending the
20000 @code{:PORT} suffix. By default, it uses the Jami bootstrap nodes, but
20001 any host can be specified here. It's also possible to disable
20002 bootstrapping by explicitly setting this field to the
20003 @code{%unset-value} value.
20005 @item @code{port} (default: @code{4222}) (type: maybe-number)
20006 The UDP port to bind to. When left unspecified, an available port is
20007 automatically selected.
20009 @item @code{proxy-server-port} (type: maybe-number)
20010 Spawn a proxy server listening on the specified port.
20012 @item @code{proxy-server-port-tls} (type: maybe-number)
20013 Spawn a proxy server listening to TLS connections on the specified port.
20019 @defvr {Scheme Variable} tor-service-type
20020 This is the type for a service that runs the @uref{https://torproject.org,
20021 Tor} anonymous networking daemon. The service is configured using a
20022 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
20023 @code{tor} unprivileged user, which is a member of the @code{tor} group.
20027 @deftp {Data Type} tor-configuration
20029 @item @code{tor} (default: @code{tor})
20030 The package that provides the Tor daemon. This package is expected to provide
20031 the daemon at @file{bin/tor} relative to its output directory. The default
20032 package is the @uref{https://www.torproject.org, Tor Project's}
20035 @item @code{config-file} (default: @code{(plain-file "empty" "")})
20036 The configuration file to use. It will be appended to a default configuration
20037 file, and the final configuration file will be passed to @code{tor} via its
20038 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
20039 file-like objects}). See @code{man tor} for details on the configuration file
20042 @item @code{hidden-services} (default: @code{'()})
20043 The list of @code{<hidden-service>} records to use. For any hidden service
20044 you include in this list, appropriate configuration to enable the hidden
20045 service will be automatically added to the default configuration file. You
20046 may conveniently create @code{<hidden-service>} records using the
20047 @code{tor-hidden-service} procedure described below.
20049 @item @code{socks-socket-type} (default: @code{'tcp})
20050 The default socket type that Tor should use for its SOCKS socket. This must
20051 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
20052 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
20053 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
20054 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
20057 If you want to customize the SOCKS socket in more detail, leave
20058 @code{socks-socket-type} at its default value of @code{'tcp} and use
20059 @code{config-file} to override the default by providing your own
20060 @code{SocksPort} option.
20062 @item @code{control-socket?} (default: @code{#f})
20063 Whether or not to provide a ``control socket'' by which Tor can be
20064 controlled to, for instance, dynamically instantiate tor onion services.
20065 If @code{#t}, Tor will listen for control commands on the UNIX domain socket
20066 @file{/var/run/tor/control-sock}, which will be made writable by members of the
20072 @cindex hidden service
20073 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
20074 Define a new Tor @dfn{hidden service} called @var{name} and implementing
20075 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
20078 '((22 "127.0.0.1:22")
20079 (80 "127.0.0.1:8080"))
20082 In this example, port 22 of the hidden service is mapped to local port 22, and
20083 port 80 is mapped to local port 8080.
20085 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
20086 the @file{hostname} file contains the @code{.onion} host name for the hidden
20089 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
20090 project's documentation} for more information.
20093 The @code{(gnu services rsync)} module provides the following services:
20095 You might want an rsync daemon if you have files that you want available
20096 so anyone (or just yourself) can download existing files or upload new
20099 @deffn {Scheme Variable} rsync-service-type
20100 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
20101 The value for this service type is a
20102 @command{rsync-configuration} record as in this example:
20105 ;; Export two directories over rsync. By default rsync listens on
20106 ;; all the network interfaces.
20107 (service rsync-service-type
20108 (rsync-configuration
20109 (modules (list (rsync-module
20111 (file-name "/srv/zik")
20115 (file-name "/home/charlie/movies"))))))
20118 See below for details about @code{rsync-configuration}.
20121 @deftp {Data Type} rsync-configuration
20122 Data type representing the configuration for @code{rsync-service}.
20125 @item @code{package} (default: @var{rsync})
20126 @code{rsync} package to use.
20128 @item @code{address} (default: @code{#f})
20129 IP address on which @command{rsync} listens for incoming connections.
20130 If unspecified, it defaults to listening on all available addresses.
20132 @item @code{port-number} (default: @code{873})
20133 TCP port on which @command{rsync} listens for incoming connections. If port
20134 is less than @code{1024} @command{rsync} needs to be started as the
20135 @code{root} user and group.
20137 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
20138 Name of the file where @command{rsync} writes its PID.
20140 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
20141 Name of the file where @command{rsync} writes its lock file.
20143 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
20144 Name of the file where @command{rsync} writes its log file.
20146 @item @code{user} (default: @code{"root"})
20147 Owner of the @code{rsync} process.
20149 @item @code{group} (default: @code{"root"})
20150 Group of the @code{rsync} process.
20152 @item @code{uid} (default: @code{"rsyncd"})
20153 User name or user ID that file transfers to and from that module should take
20154 place as when the daemon was run as @code{root}.
20156 @item @code{gid} (default: @code{"rsyncd"})
20157 Group name or group ID that will be used when accessing the module.
20159 @item @code{modules} (default: @code{%default-modules})
20160 List of ``modules''---i.e., directories exported over rsync. Each
20161 element must be a @code{rsync-module} record, as described below.
20165 @deftp {Data Type} rsync-module
20166 This is the data type for rsync ``modules''. A module is a directory
20167 exported over the rsync protocol. The available fields are as follows:
20171 The module name. This is the name that shows up in URLs. For example,
20172 if the module is called @code{music}, the corresponding URL will be
20173 @code{rsync://host.example.org/music}.
20175 @item @code{file-name}
20176 Name of the directory being exported.
20178 @item @code{comment} (default: @code{""})
20179 Comment associated with the module. Client user interfaces may display
20180 it when they obtain the list of available modules.
20182 @item @code{read-only?} (default: @code{#t})
20183 Whether or not client will be able to upload files. If this is false,
20184 the uploads will be authorized if permissions on the daemon side permit
20187 @item @code{chroot?} (default: @code{#t})
20188 When this is true, the rsync daemon changes root to the module's
20189 directory before starting file transfers with the client. This improves
20190 security, but requires rsync to run as root.
20192 @item @code{timeout} (default: @code{300})
20193 Idle time in seconds after which the daemon closes a connection with the
20198 The @code{(gnu services syncthing)} module provides the following services:
20201 You might want a syncthing daemon if you have files between two or more
20202 computers and want to sync them in real time, safely protected from
20205 @deffn {Scheme Variable} syncthing-service-type
20206 This is the service type for the @uref{https://syncthing.net/,
20207 syncthing} daemon, The value for this service type is a
20208 @command{syncthing-configuration} record as in this example:
20211 (service syncthing-service-type
20212 (syncthing-configuration (user "alice")))
20215 See below for details about @code{syncthing-configuration}.
20217 @deftp {Data Type} syncthing-configuration
20218 Data type representing the configuration for @code{syncthing-service-type}.
20221 @item @code{syncthing} (default: @var{syncthing})
20222 @code{syncthing} package to use.
20224 @item @code{arguments} (default: @var{'()})
20225 List of command-line arguments passing to @code{syncthing} binary.
20227 @item @code{logflags} (default: @var{0})
20228 Sum of logging flags, see
20229 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
20231 @item @code{user} (default: @var{#f})
20232 The user as which the Syncthing service is to be run.
20233 This assumes that the specified user exists.
20235 @item @code{group} (default: @var{"users"})
20236 The group as which the Syncthing service is to be run.
20237 This assumes that the specified group exists.
20239 @item @code{home} (default: @var{#f})
20240 Common configuration and data directory. The default configuration
20241 directory is @file{$HOME} of the specified Syncthing @code{user}.
20247 Furthermore, @code{(gnu services ssh)} provides the following services.
20251 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
20252 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
20253 [#:allow-empty-passwords? #f] [#:root-login? #f] @
20254 [#:syslog-output? #t] [#:x11-forwarding? #t] @
20255 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
20256 [#:public-key-authentication? #t] [#:initialize? #t]
20257 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
20258 @var{host-key} must designate a file containing the host key, and readable
20261 When @var{daemonic?} is true, @command{lshd} will detach from the
20262 controlling terminal and log its output to syslogd, unless one sets
20263 @var{syslog-output?} to false. Obviously, it also makes lsh-service
20264 depend on existence of syslogd service. When @var{pid-file?} is true,
20265 @command{lshd} writes its PID to the file called @var{pid-file}.
20267 When @var{initialize?} is true, automatically create the seed and host key
20268 upon service activation if they do not exist yet. This may take long and
20269 require interaction.
20271 When @var{initialize?} is false, it is up to the user to initialize the
20272 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
20273 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
20274 basics,,, lsh, LSH Manual}).
20276 When @var{interfaces} is empty, lshd listens for connections on all the
20277 network interfaces; otherwise, @var{interfaces} must be a list of host names
20280 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
20281 passwords, and @var{root-login?} specifies whether to accept log-ins as
20284 The other options should be self-descriptive.
20289 @deffn {Scheme Variable} openssh-service-type
20290 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
20291 shell daemon, @command{sshd}. Its value must be an
20292 @code{openssh-configuration} record as in this example:
20295 (service openssh-service-type
20296 (openssh-configuration
20297 (x11-forwarding? #t)
20298 (permit-root-login 'prohibit-password)
20300 `(("alice" ,(local-file "alice.pub"))
20301 ("bob" ,(local-file "bob.pub"))))))
20304 See below for details about @code{openssh-configuration}.
20306 This service can be extended with extra authorized keys, as in this
20310 (service-extension openssh-service-type
20311 (const `(("charlie"
20312 ,(local-file "charlie.pub")))))
20316 @deftp {Data Type} openssh-configuration
20317 This is the configuration record for OpenSSH's @command{sshd}.
20320 @item @code{openssh} (default @var{openssh})
20321 The OpenSSH package to use.
20323 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
20324 Name of the file where @command{sshd} writes its PID.
20326 @item @code{port-number} (default: @code{22})
20327 TCP port on which @command{sshd} listens for incoming connections.
20329 @item @code{max-connections} (default: @code{200})
20330 Hard limit on the maximum number of simultaneous client connections,
20331 enforced by the inetd-style Shepherd service (@pxref{Service De- and
20332 Constructors, @code{make-inetd-constructor},, shepherd, The GNU Shepherd
20335 @item @code{permit-root-login} (default: @code{#f})
20336 This field determines whether and when to allow logins as root. If
20337 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
20338 If it's the symbol @code{'prohibit-password}, then root logins are
20339 permitted but not with password-based authentication.
20341 @item @code{allow-empty-passwords?} (default: @code{#f})
20342 When true, users with empty passwords may log in. When false, they may
20345 @item @code{password-authentication?} (default: @code{#t})
20346 When true, users may log in with their password. When false, they have
20347 other authentication methods.
20349 @item @code{public-key-authentication?} (default: @code{#t})
20350 When true, users may log in using public key authentication. When
20351 false, users have to use other authentication method.
20353 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
20354 This is used only by protocol version 2.
20356 @item @code{x11-forwarding?} (default: @code{#f})
20357 When true, forwarding of X11 graphical client connections is
20358 enabled---in other words, @command{ssh} options @option{-X} and
20359 @option{-Y} will work.
20361 @item @code{allow-agent-forwarding?} (default: @code{#t})
20362 Whether to allow agent forwarding.
20364 @item @code{allow-tcp-forwarding?} (default: @code{#t})
20365 Whether to allow TCP forwarding.
20367 @item @code{gateway-ports?} (default: @code{#f})
20368 Whether to allow gateway ports.
20370 @item @code{challenge-response-authentication?} (default: @code{#f})
20371 Specifies whether challenge response authentication is allowed (e.g.@: via
20374 @item @code{use-pam?} (default: @code{#t})
20375 Enables the Pluggable Authentication Module interface. If set to
20376 @code{#t}, this will enable PAM authentication using
20377 @code{challenge-response-authentication?} and
20378 @code{password-authentication?}, in addition to PAM account and session
20379 module processing for all authentication types.
20381 Because PAM challenge response authentication usually serves an
20382 equivalent role to password authentication, you should disable either
20383 @code{challenge-response-authentication?} or
20384 @code{password-authentication?}.
20386 @item @code{print-last-log?} (default: @code{#t})
20387 Specifies whether @command{sshd} should print the date and time of the
20388 last user login when a user logs in interactively.
20390 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
20391 Configures external subsystems (e.g.@: file transfer daemon).
20393 This is a list of two-element lists, each of which containing the
20394 subsystem name and a command (with optional arguments) to execute upon
20397 The command @command{internal-sftp} implements an in-process SFTP
20398 server. Alternatively, one can specify the @command{sftp-server} command:
20400 (service openssh-service-type
20401 (openssh-configuration
20403 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
20406 @item @code{accepted-environment} (default: @code{'()})
20407 List of strings describing which environment variables may be exported.
20409 Each string gets on its own line. See the @code{AcceptEnv} option in
20410 @code{man sshd_config}.
20412 This example allows ssh-clients to export the @env{COLORTERM} variable.
20413 It is set by terminal emulators, which support colors. You can use it in
20414 your shell's resource file to enable colors for the prompt and commands
20415 if this variable is set.
20418 (service openssh-service-type
20419 (openssh-configuration
20420 (accepted-environment '("COLORTERM"))))
20423 @item @code{authorized-keys} (default: @code{'()})
20424 @cindex authorized keys, SSH
20425 @cindex SSH authorized keys
20426 This is the list of authorized keys. Each element of the list is a user
20427 name followed by one or more file-like objects that represent SSH public
20431 (openssh-configuration
20433 `(("rekado" ,(local-file "rekado.pub"))
20434 ("chris" ,(local-file "chris.pub"))
20435 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
20439 registers the specified public keys for user accounts @code{rekado},
20440 @code{chris}, and @code{root}.
20442 Additional authorized keys can be specified @i{via}
20443 @code{service-extension}.
20445 Note that this does @emph{not} interfere with the use of
20446 @file{~/.ssh/authorized_keys}.
20448 @item @code{generate-host-keys?} (default: @code{#t})
20449 Whether to generate host key pairs with @command{ssh-keygen -A} under
20450 @file{/etc/ssh} if there are none.
20452 Generating key pairs takes a few seconds when enough entropy is
20453 available and is only done once. You might want to turn it off for
20454 instance in a virtual machine that does not need it because host keys
20455 are provided in some other way, and where the extra boot time is a
20458 @item @code{log-level} (default: @code{'info})
20459 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
20460 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
20461 page for @file{sshd_config} for the full list of level names.
20463 @item @code{extra-content} (default: @code{""})
20464 This field can be used to append arbitrary text to the configuration file. It
20465 is especially useful for elaborate configurations that cannot be expressed
20466 otherwise. This configuration, for example, would generally disable root
20467 logins, but permit them from one specific IP address:
20470 (openssh-configuration
20472 Match Address 192.168.0.1
20473 PermitRootLogin yes"))
20479 @deffn {Scheme Procedure} dropbear-service [@var{config}]
20480 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
20481 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
20484 For example, to specify a Dropbear service listening on port 1234, add
20485 this call to the operating system's @code{services} field:
20488 (dropbear-service (dropbear-configuration
20489 (port-number 1234)))
20493 @deftp {Data Type} dropbear-configuration
20494 This data type represents the configuration of a Dropbear SSH daemon.
20497 @item @code{dropbear} (default: @var{dropbear})
20498 The Dropbear package to use.
20500 @item @code{port-number} (default: 22)
20501 The TCP port where the daemon waits for incoming connections.
20503 @item @code{syslog-output?} (default: @code{#t})
20504 Whether to enable syslog output.
20506 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
20507 File name of the daemon's PID file.
20509 @item @code{root-login?} (default: @code{#f})
20510 Whether to allow @code{root} logins.
20512 @item @code{allow-empty-passwords?} (default: @code{#f})
20513 Whether to allow empty passwords.
20515 @item @code{password-authentication?} (default: @code{#t})
20516 Whether to enable password-based authentication.
20521 @deffn {Scheme Variable} autossh-service-type
20522 This is the type for the @uref{https://www.harding.motd.ca/autossh,
20523 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
20524 restarting it as necessary should it die or stop passing traffic.
20525 AutoSSH can be run manually from the command-line by passing arguments
20526 to the binary @command{autossh} from the package @code{autossh}, but it
20527 can also be run as a Guix service. This latter use case is documented
20530 AutoSSH can be used to forward local traffic to a remote machine using
20531 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
20534 For example, to specify a service running autossh as the user
20535 @code{pino} and forwarding all local connections to port @code{8081} to
20536 @code{remote:8081} using an SSH tunnel, add this call to the operating
20537 system's @code{services} field:
20540 (service autossh-service-type
20541 (autossh-configuration
20543 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
20547 @deftp {Data Type} autossh-configuration
20548 This data type represents the configuration of an AutoSSH service.
20552 @item @code{user} (default @code{"autossh"})
20553 The user as which the AutoSSH service is to be run.
20554 This assumes that the specified user exists.
20556 @item @code{poll} (default @code{600})
20557 Specifies the connection poll time in seconds.
20559 @item @code{first-poll} (default @code{#f})
20560 Specifies how many seconds AutoSSH waits before the first connection
20561 test. After this first test, polling is resumed at the pace defined in
20562 @code{poll}. When set to @code{#f}, the first poll is not treated
20563 specially and will also use the connection poll specified in
20566 @item @code{gate-time} (default @code{30})
20567 Specifies how many seconds an SSH connection must be active before it is
20568 considered successful.
20570 @item @code{log-level} (default @code{1})
20571 The log level, corresponding to the levels used by syslog---so @code{0}
20572 is the most silent while @code{7} is the chattiest.
20574 @item @code{max-start} (default @code{#f})
20575 The maximum number of times SSH may be (re)started before AutoSSH exits.
20576 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
20578 @item @code{message} (default @code{""})
20579 The message to append to the echo message sent when testing connections.
20581 @item @code{port} (default @code{"0"})
20582 The ports used for monitoring the connection. When set to @code{"0"},
20583 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
20584 a positive integer, ports @var{n} and @var{n}+1 are used for
20585 monitoring the connection, such that port @var{n} is the base
20586 monitoring port and @code{n+1} is the echo port. When set to
20587 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
20588 integers, the ports @var{n} and @var{m} are used for monitoring the
20589 connection, such that port @var{n} is the base monitoring port and
20590 @var{m} is the echo port.
20592 @item @code{ssh-options} (default @code{'()})
20593 The list of command-line arguments to pass to @command{ssh} when it is
20594 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
20595 may cause undefined behaviour.
20601 @deffn {Scheme Variable} webssh-service-type
20602 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
20603 program that runs a web SSH client. WebSSH can be run manually from the
20604 command-line by passing arguments to the binary @command{wssh} from the
20605 package @code{webssh}, but it can also be run as a Guix service. This
20606 latter use case is documented here.
20608 For example, to specify a service running WebSSH on loopback interface
20609 on port @code{8888} with reject policy with a list of allowed to
20610 connection hosts, and NGINX as a reverse-proxy to this service listening
20611 for HTTPS connection, add this call to the operating system's
20612 @code{services} field:
20615 (service webssh-service-type
20616 (webssh-configuration (address "127.0.0.1")
20619 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
20620 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
20622 (service nginx-service-type
20623 (nginx-configuration
20626 (nginx-server-configuration
20627 (inherit %webssh-configuration-nginx)
20628 (server-name '("webssh.example.com"))
20629 (listen '("443 ssl"))
20630 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
20631 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
20633 (cons (nginx-location-configuration
20634 (uri "/.well-known")
20635 (body '("root /var/www;")))
20636 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
20640 @deftp {Data Type} webssh-configuration
20641 Data type representing the configuration for @code{webssh-service}.
20644 @item @code{package} (default: @var{webssh})
20645 @code{webssh} package to use.
20647 @item @code{user-name} (default: @var{"webssh"})
20648 User name or user ID that file transfers to and from that module should take
20651 @item @code{group-name} (default: @var{"webssh"})
20652 Group name or group ID that will be used when accessing the module.
20654 @item @code{address} (default: @var{#f})
20655 IP address on which @command{webssh} listens for incoming connections.
20657 @item @code{port} (default: @var{8888})
20658 TCP port on which @command{webssh} listens for incoming connections.
20660 @item @code{policy} (default: @var{#f})
20661 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
20663 @item @code{known-hosts} (default: @var{'()})
20664 List of hosts which allowed for SSH connection from @command{webssh}.
20666 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
20667 Name of the file where @command{webssh} writes its log file.
20669 @item @code{log-level} (default: @var{#f})
20675 @defvr {Scheme Variable} %facebook-host-aliases
20676 This variable contains a string for use in @file{/etc/hosts}
20677 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
20678 line contains a entry that maps a known server name of the Facebook
20679 on-line service---e.g., @code{www.facebook.com}---to the local
20680 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
20682 This variable is typically used in the @code{hosts-file} field of an
20683 @code{operating-system} declaration (@pxref{operating-system Reference,
20684 @file{/etc/hosts}}):
20687 (use-modules (gnu) (guix))
20690 (host-name "mymachine")
20693 ;; Create a /etc/hosts file with aliases for "localhost"
20694 ;; and "mymachine", as well as for Facebook servers.
20695 (plain-file "hosts"
20696 (string-append (local-host-aliases host-name)
20697 %facebook-host-aliases))))
20700 This mechanism can prevent programs running locally, such as Web
20701 browsers, from accessing Facebook.
20704 The @code{(gnu services avahi)} provides the following definition.
20706 @defvr {Scheme Variable} avahi-service-type
20707 This is the service that runs @command{avahi-daemon}, a system-wide
20708 mDNS/DNS-SD responder that allows for service discovery and
20709 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
20710 Its value must be an @code{avahi-configuration} record---see below.
20712 This service extends the name service cache daemon (nscd) so that it can
20713 resolve @code{.local} host names using
20714 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
20715 Service Switch}, for information on host name resolution.
20717 Additionally, add the @var{avahi} package to the system profile so that
20718 commands such as @command{avahi-browse} are directly usable.
20721 @deftp {Data Type} avahi-configuration
20722 Data type representation the configuration for Avahi.
20726 @item @code{host-name} (default: @code{#f})
20727 If different from @code{#f}, use that as the host name to
20728 publish for this machine; otherwise, use the machine's actual host name.
20730 @item @code{publish?} (default: @code{#t})
20731 When true, allow host names and services to be published (broadcast) over the
20734 @item @code{publish-workstation?} (default: @code{#t})
20735 When true, @command{avahi-daemon} publishes the machine's host name and IP
20736 address via mDNS on the local network. To view the host names published on
20737 your local network, you can run:
20740 avahi-browse _workstation._tcp
20743 @item @code{wide-area?} (default: @code{#f})
20744 When true, DNS-SD over unicast DNS is enabled.
20746 @item @code{ipv4?} (default: @code{#t})
20747 @itemx @code{ipv6?} (default: @code{#t})
20748 These fields determine whether to use IPv4/IPv6 sockets.
20750 @item @code{domains-to-browse} (default: @code{'()})
20751 This is a list of domains to browse.
20755 @deffn {Scheme Variable} openvswitch-service-type
20756 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
20757 service, whose value should be an @code{openvswitch-configuration}
20761 @deftp {Data Type} openvswitch-configuration
20762 Data type representing the configuration of Open vSwitch, a multilayer
20763 virtual switch which is designed to enable massive network automation
20764 through programmatic extension.
20767 @item @code{package} (default: @var{openvswitch})
20768 Package object of the Open vSwitch.
20773 @defvr {Scheme Variable} pagekite-service-type
20774 This is the service type for the @uref{https://pagekite.net, PageKite} service,
20775 a tunneling solution for making localhost servers publicly visible, even from
20776 behind restrictive firewalls or NAT without forwarded ports. The value for
20777 this service type is a @code{pagekite-configuration} record.
20779 Here's an example exposing the local HTTP and SSH daemons:
20782 (service pagekite-service-type
20783 (pagekite-configuration
20784 (kites '("http:@@kitename:localhost:80:@@kitesecret"
20785 "raw/22:@@kitename:localhost:22:@@kitesecret"))
20786 (extra-file "/etc/pagekite.rc")))
20790 @deftp {Data Type} pagekite-configuration
20791 Data type representing the configuration of PageKite.
20794 @item @code{package} (default: @var{pagekite})
20795 Package object of PageKite.
20797 @item @code{kitename} (default: @code{#f})
20798 PageKite name for authenticating to the frontend server.
20800 @item @code{kitesecret} (default: @code{#f})
20801 Shared secret for authenticating to the frontend server. You should probably
20802 put this inside @code{extra-file} instead.
20804 @item @code{frontend} (default: @code{#f})
20805 Connect to the named PageKite frontend server instead of the
20806 @uref{https://pagekite.net,,pagekite.net} service.
20808 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
20809 List of service kites to use. Exposes HTTP on port 80 by default. The format
20810 is @code{proto:kitename:host:port:secret}.
20812 @item @code{extra-file} (default: @code{#f})
20813 Extra configuration file to read, which you are expected to create manually.
20814 Use this to add additional options and manage shared secrets out-of-band.
20819 @defvr {Scheme Variable} yggdrasil-service-type
20820 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
20821 Yggdrasil network}, an early-stage implementation of a fully end-to-end
20822 encrypted IPv6 network.
20825 Yggdrasil provides name-independent routing with cryptographically generated
20826 addresses. Static addressing means you can keep the same address as long as
20827 you want, even if you move to a new location, or generate a new address (by
20828 generating new keys) whenever you want.
20829 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
20832 Pass it a value of @code{yggdrasil-configuration} to connect it to public
20833 peers and/or local peers.
20835 Here is an example using public peers and a static address. The static
20836 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
20837 (the default value for @code{config-file}).
20840 ;; part of the operating-system declaration
20841 (service yggdrasil-service-type
20842 (yggdrasil-configuration
20843 (autoconf? #f) ;; use only the public peers
20846 ;; https://github.com/yggdrasil-network/public-peers
20847 '((peers . #("tcp://1.2.3.4:1337"))))
20848 ;; /etc/yggdrasil-private.conf is the default value for config-file
20852 # sample content for /etc/yggdrasil-private.conf
20854 # Your public key. Your peers may ask you for this to put
20855 # into their AllowedPublicKeys configuration.
20856 PublicKey: 64277...
20858 # Your private key. DO NOT share this with anyone!
20859 PrivateKey: 5c750...
20864 @deftp {Data Type} yggdrasil-configuration
20865 Data type representing the configuration of Yggdrasil.
20868 @item @code{package} (default: @code{yggdrasil})
20869 Package object of Yggdrasil.
20871 @item @code{json-config} (default: @code{'()})
20872 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
20873 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
20874 the Guix store, which is readable to all users. @strong{Do not store your
20875 private keys in it}. See the output of @code{yggdrasil -genconf} for a
20876 quick overview of valid keys and their default values.
20878 @item @code{autoconf?} (default: @code{#f})
20879 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
20880 and peer with IPv6 neighbors.
20882 @item @code{log-level} (default: @code{'info})
20883 How much detail to include in logs. Use @code{'debug} for more detail.
20885 @item @code{log-to} (default: @code{'stdout})
20886 Where to send logs. By default, the service logs standard output to
20887 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
20888 sends output to the running syslog service.
20890 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
20891 What HJSON file to load sensitive data from. This is where private keys
20892 should be stored, which are necessary to specify if you don't want a
20893 randomized address after each restart. Use @code{#f} to disable. Options
20894 defined in this file take precedence over @code{json-config}. Use the output
20895 of @code{yggdrasil -genconf} as a starting point. To configure a static
20896 address, delete everything except these options:
20899 @item @code{EncryptionPublicKey}
20900 @item @code{EncryptionPrivateKey}
20901 @item @code{SigningPublicKey}
20902 @item @code{SigningPrivateKey}
20908 @defvr {Scheme Variable} ipfs-service-type
20909 The service type for connecting to the @uref{https://ipfs.io,IPFS network},
20910 a global, versioned, peer-to-peer file system. Pass it a
20911 @code{ipfs-configuration} to change the ports used for the gateway and API.
20913 Here's an example configuration, using some non-standard ports:
20916 (service ipfs-service-type
20917 (ipfs-configuration
20918 (gateway "/ip4/127.0.0.1/tcp/8880")
20919 (api "/ip4/127.0.0.1/tcp/8881")))
20923 @deftp {Data Type} ipfs-configuration
20924 Data type representing the configuration of IPFS.
20927 @item @code{package} (default: @code{go-ipfs})
20928 Package object of IPFS.
20930 @item @code{gateway} (default: @code{"/ip4/127.0.0.1/tcp/8082"})
20931 Address of the gateway, in ‘multiaddress’ format.
20933 @item @code{api} (default: @code{"/ip4/127.0.0.1/tcp/5001"})
20934 Address of the API endpoint, in ‘multiaddress’ format.
20939 @deffn {Scheme Variable} keepalived-service-type
20940 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
20941 routing software, @command{keepalived}. Its value must be an
20942 @code{keepalived-configuration} record as in this example for master
20946 (service keepalived-service-type
20947 (keepalived-configuration
20948 (config-file (local-file "keepalived-master.conf"))))
20951 where @file{keepalived-master.conf}:
20954 vrrp_instance my-group @{
20957 virtual_router_id 100
20959 unicast_peer @{ 10.0.0.2 @}
20960 virtual_ipaddress @{
20966 and for backup machine:
20969 (service keepalived-service-type
20970 (keepalived-configuration
20971 (config-file (local-file "keepalived-backup.conf"))))
20974 where @file{keepalived-backup.conf}:
20977 vrrp_instance my-group @{
20980 virtual_router_id 100
20982 unicast_peer @{ 10.0.0.3 @}
20983 virtual_ipaddress @{
20990 @node Unattended Upgrades
20991 @subsection Unattended Upgrades
20993 @cindex unattended upgrades
20994 @cindex upgrades, unattended
20995 Guix provides a service to perform @emph{unattended upgrades}:
20996 periodically, the system automatically reconfigures itself from the
20997 latest Guix. Guix System has several properties that make unattended
21002 upgrades are transactional (either the upgrade succeeds or it fails, but
21003 you cannot end up with an ``in-between'' system state);
21005 the upgrade log is kept---you can view it with @command{guix system
21006 list-generations}---and you can roll back to any previous generation,
21007 should the upgraded system fail to behave as intended;
21009 channel code is authenticated so you know you can only run genuine code
21010 (@pxref{Channels});
21012 @command{guix system reconfigure} prevents downgrades, which makes it
21013 immune to @dfn{downgrade attacks}.
21016 To set up unattended upgrades, add an instance of
21017 @code{unattended-upgrade-service-type} like the one below to the list of
21018 your operating system services:
21021 (service unattended-upgrade-service-type)
21024 The defaults above set up weekly upgrades: every Sunday at midnight.
21025 You do not need to provide the operating system configuration file: it
21026 uses @file{/run/current-system/configuration.scm}, which ensures it
21027 always uses your latest configuration---@pxref{provenance-service-type},
21028 for more information about this file.
21030 There are several things that can be configured, in particular the
21031 periodicity and services (daemons) to be restarted upon completion.
21032 When the upgrade is successful, the service takes care of deleting
21033 system generations older that some threshold, as per @command{guix
21034 system delete-generations}. See the reference below for details.
21036 To ensure that upgrades are actually happening, you can run
21037 @command{guix system describe}. To investigate upgrade failures, visit
21038 the unattended upgrade log file (see below).
21040 @defvr {Scheme Variable} unattended-upgrade-service-type
21041 This is the service type for unattended upgrades. It sets up an mcron
21042 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
21043 reconfigure} from the latest version of the specified channels.
21045 Its value must be a @code{unattended-upgrade-configuration} record (see
21049 @deftp {Data Type} unattended-upgrade-configuration
21050 This data type represents the configuration of the unattended upgrade
21051 service. The following fields are available:
21054 @item @code{schedule} (default: @code{"30 01 * * 0"})
21055 This is the schedule of upgrades, expressed as a gexp containing an
21056 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
21057 mcron, GNU@tie{}mcron}).
21059 @item @code{channels} (default: @code{#~%default-channels})
21060 This gexp specifies the channels to use for the upgrade
21061 (@pxref{Channels}). By default, the tip of the official @code{guix}
21064 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
21065 This field specifies the operating system configuration file to use.
21066 The default is to reuse the config file of the current configuration.
21068 There are cases, though, where referring to
21069 @file{/run/current-system/configuration.scm} is not enough, for instance
21070 because that file refers to extra files (SSH public keys, extra
21071 configuration files, etc.) @i{via} @code{local-file} and similar
21072 constructs. For those cases, we recommend something along these lines:
21075 (unattended-upgrade-configuration
21076 (operating-system-file
21077 (file-append (local-file "." "config-dir" #:recursive? #t)
21081 The effect here is to import all of the current directory into the
21082 store, and to refer to @file{config.scm} within that directory.
21083 Therefore, uses of @code{local-file} within @file{config.scm} will work
21084 as expected. @xref{G-Expressions}, for information about
21085 @code{local-file} and @code{file-append}.
21087 @item @code{services-to-restart} (default: @code{'(mcron)})
21088 This field specifies the Shepherd services to restart when the upgrade
21091 Those services are restarted right away upon completion, as with
21092 @command{herd restart}, which ensures that the latest version is
21093 running---remember that by default @command{guix system reconfigure}
21094 only restarts services that are not currently running, which is
21095 conservative: it minimizes disruption but leaves outdated services
21098 Use @command{herd status} to find out candidates for restarting.
21099 @xref{Services}, for general information about services. Common
21100 services to restart would include @code{ntpd} and @code{ssh-daemon}.
21102 By default, the @code{mcron} service is restarted. This ensures that
21103 the latest version of the unattended upgrade job will be used next time.
21105 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
21106 This is the expiration time in seconds for system generations. System
21107 generations older that this amount of time are deleted with
21108 @command{guix system delete-generations} when an upgrade completes.
21111 The unattended upgrade service does not run the garbage collector. You
21112 will probably want to set up your own mcron job to run @command{guix gc}
21116 @item @code{maximum-duration} (default: @code{3600})
21117 Maximum duration in seconds for the upgrade; past that time, the upgrade
21120 This is primarily useful to ensure the upgrade does not end up
21121 rebuilding or re-downloading ``the world''.
21123 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
21124 File where unattended upgrades are logged.
21129 @subsection X Window
21132 @cindex X Window System
21133 @cindex login manager
21134 Support for the X Window graphical display system---specifically
21135 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
21136 there is no @code{xorg-service} procedure. Instead, the X server is
21137 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
21140 @cindex GNOME, login manager
21142 GDM of course allows users to log in into window managers and desktop
21143 environments other than GNOME; for those using GNOME, GDM is required for
21144 features such as automatic screen locking.
21146 @cindex window manager
21147 To use X11, you must install at least one @dfn{window manager}---for
21148 example the @code{windowmaker} or @code{openbox} packages---preferably
21149 by adding it to the @code{packages} field of your operating system
21150 definition (@pxref{operating-system Reference, system-wide packages}).
21152 @anchor{wayland-gdm}
21153 GDM also supports Wayland: it can itself use Wayland instead of X11 for
21154 its user interface, and it can also start Wayland sessions. The former is
21155 required for the latter, to enable, set @code{wayland?} to @code{#t} in
21156 @code{gdm-configuration}.
21158 @defvr {Scheme Variable} gdm-service-type
21159 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
21160 Desktop Manager} (GDM), a program that manages graphical display servers and
21161 handles graphical user logins. Its value must be a @code{gdm-configuration}
21164 @cindex session types
21165 GDM looks for @dfn{session types} described by the @file{.desktop} files in
21166 @file{/run/current-system/profile/share/xsessions} (for X11 sessions) and
21167 @file{/run/current-system/profile/share/wayland-sessions} (for Wayland
21168 sessions) and allows users to choose a session from the log-in screen.
21169 Packages such as @code{gnome}, @code{xfce}, @code{i3} and @code{sway} provide
21170 @file{.desktop} files; adding them to the system-wide set of packages
21171 automatically makes them available at the log-in screen.
21173 In addition, @file{~/.xsession} files are honored. When available,
21174 @file{~/.xsession} must be an executable that starts a window manager
21175 and/or other X clients.
21178 @deftp {Data Type} gdm-configuration
21180 @item @code{auto-login?} (default: @code{#f})
21181 @itemx @code{default-user} (default: @code{#f})
21182 When @code{auto-login?} is false, GDM presents a log-in screen.
21184 When @code{auto-login?} is true, GDM logs in directly as
21185 @code{default-user}.
21187 @item @code{auto-suspend?} (default @code{#t})
21188 When true, GDM will automatically suspend to RAM when nobody is
21189 physically connected. When a machine is used via remote desktop or SSH,
21190 this should be set to false to avoid GDM interrupting remote sessions or
21191 rendering the machine unavailable.
21193 @item @code{debug?} (default: @code{#f})
21194 When true, GDM writes debug messages to its log.
21196 @item @code{gnome-shell-assets} (default: ...)
21197 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
21199 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
21200 Configuration of the Xorg graphical server.
21202 @item @code{x-session} (default: @code{(xinitrc)})
21203 Script to run before starting a X session.
21205 @item @code{xdmcp?} (default: @code{#f})
21206 When true, enable the X Display Manager Control Protocol (XDMCP). This
21207 should only be enabled in trusted environments, as the protocol is not
21208 secure. When enabled, GDM listens for XDMCP queries on the UDP port
21211 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
21212 File name of the @code{dbus-daemon} executable.
21214 @item @code{gdm} (default: @code{gdm})
21215 The GDM package to use.
21217 @item @code{wayland?} (default: @code{#f})
21218 When true, enables Wayland in GDM, necessary to use Wayland sessions.
21220 @item @code{wayland-session} (default: @code{gdm-wayland-session-wrapper})
21221 The Wayland session wrapper to use, needed to setup the
21226 @defvr {Scheme Variable} slim-service-type
21227 This is the type for the SLiM graphical login manager for X11.
21229 Like GDM, SLiM looks for session types described by @file{.desktop} files and
21230 allows users to choose a session from the log-in screen using @kbd{F1}. It
21231 also honors @file{~/.xsession} files.
21233 Unlike GDM, SLiM does not spawn the user session on a different VT after
21234 logging in, which means that you can only start one graphical session. If you
21235 want to be able to run multiple graphical sessions at the same time you have
21236 to add multiple SLiM services to your system services. The following example
21237 shows how to replace the default GDM service with two SLiM services on tty7
21241 (use-modules (gnu services)
21242 (gnu services desktop)
21243 (gnu services xorg))
21247 (services (cons* (service slim-service-type (slim-configuration
21250 (service slim-service-type (slim-configuration
21253 (modify-services %desktop-services
21254 (delete gdm-service-type)))))
21259 @deftp {Data Type} slim-configuration
21260 Data type representing the configuration of @code{slim-service-type}.
21263 @item @code{allow-empty-passwords?} (default: @code{#t})
21264 Whether to allow logins with empty passwords.
21266 @item @code{gnupg?} (default: @code{#f})
21267 If enabled, @code{pam-gnupg} will attempt to automatically unlock the
21268 user's GPG keys with the login password via @code{gpg-agent}. The
21269 keygrips of all keys to be unlocked should be written to
21270 @file{~/.pam-gnupg}, and can be queried with @code{gpg -K
21271 --with-keygrip}. Presetting passphrases must be enabled by adding
21272 @code{allow-preset-passphrase} in @file{~/.gnupg/gpg-agent.conf}.
21274 @item @code{auto-login?} (default: @code{#f})
21275 @itemx @code{default-user} (default: @code{""})
21276 When @code{auto-login?} is false, SLiM presents a log-in screen.
21278 When @code{auto-login?} is true, SLiM logs in directly as
21279 @code{default-user}.
21281 @item @code{theme} (default: @code{%default-slim-theme})
21282 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
21283 The graphical theme to use and its name.
21285 @item @code{auto-login-session} (default: @code{#f})
21286 If true, this must be the name of the executable to start as the default
21287 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
21289 If false, a session described by one of the available @file{.desktop}
21290 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
21294 You must install at least one window manager in the system profile or in
21295 your user profile. Failing to do that, if @code{auto-login-session} is
21296 false, you will be unable to log in.
21299 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
21300 Configuration of the Xorg graphical server.
21302 @item @code{display} (default @code{":0"})
21303 The display on which to start the Xorg graphical server.
21305 @item @code{vt} (default @code{"vt7"})
21306 The VT on which to start the Xorg graphical server.
21308 @item @code{xauth} (default: @code{xauth})
21309 The XAuth package to use.
21311 @item @code{shepherd} (default: @code{shepherd})
21312 The Shepherd package used when invoking @command{halt} and
21315 @item @code{sessreg} (default: @code{sessreg})
21316 The sessreg package used in order to register the session.
21318 @item @code{slim} (default: @code{slim})
21319 The SLiM package to use.
21323 @defvr {Scheme Variable} %default-theme
21324 @defvrx {Scheme Variable} %default-theme-name
21325 The default SLiM theme and its name.
21329 @cindex login manager
21331 @defvr {Scheme Variable} sddm-service-type
21332 This is the type of the service to run the
21333 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
21334 must be a @code{sddm-configuration} record (see below).
21336 Here's an example use:
21339 (service sddm-service-type
21340 (sddm-configuration
21341 (auto-login-user "alice")
21342 (auto-login-session "xfce.desktop")))
21346 @deftp {Data Type} sddm-configuration
21347 This data type represents the configuration of the SDDM login manager.
21348 The available fields are:
21351 @item @code{sddm} (default: @code{sddm})
21352 The SDDM package to use.
21354 @item @code{display-server} (default: "x11")
21355 Select display server to use for the greeter. Valid values are
21356 @samp{"x11"} or @samp{"wayland"}.
21358 @item @code{numlock} (default: "on")
21359 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
21361 @item @code{halt-command} (default @code{#~(string-append #$shepherd "/sbin/halt")})
21362 Command to run when halting.
21364 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
21365 Command to run when rebooting.
21367 @item @code{theme} (default "maldives")
21368 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
21369 @samp{"maldives"} or @samp{"maya"}.
21371 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
21372 Directory to look for themes.
21374 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
21375 Directory to look for faces.
21377 @item @code{default-path} (default "/run/current-system/profile/bin")
21378 Default PATH to use.
21380 @item @code{minimum-uid} (default: 1000)
21381 Minimum UID displayed in SDDM and allowed for log-in.
21383 @item @code{maximum-uid} (default: 2000)
21384 Maximum UID to display in SDDM.
21386 @item @code{remember-last-user?} (default #t)
21387 Remember last user.
21389 @item @code{remember-last-session?} (default #t)
21390 Remember last session.
21392 @item @code{hide-users} (default "")
21393 Usernames to hide from SDDM greeter.
21395 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
21396 Users with shells listed will be hidden from the SDDM greeter.
21398 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
21399 Script to run before starting a wayland session.
21401 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
21402 Directory to look for desktop files starting wayland sessions.
21404 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
21405 Configuration of the Xorg graphical server.
21407 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
21410 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
21413 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
21414 Script to run after starting xorg-server.
21416 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
21417 Script to run before stopping xorg-server.
21419 @item @code{xsession-command} (default: @code{xinitrc})
21420 Script to run before starting a X session.
21422 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
21423 Directory to look for desktop files starting X sessions.
21425 @item @code{minimum-vt} (default: 7)
21428 @item @code{auto-login-user} (default "")
21429 User account that will be automatically logged in.
21430 Setting this to the empty string disables auto-login.
21432 @item @code{auto-login-session} (default "")
21433 The @file{.desktop} file name to use as the auto-login session, or the empty string.
21435 @item @code{relogin?} (default #f)
21436 Relogin after logout.
21441 @cindex lightdm, graphical login manager
21442 @cindex display manager, lightdm
21444 @defvr {Scheme Variable} lightdm-service-type
21445 This is the type of the service to run the
21446 @url{https://github.com/canonical/lightdm,LightDM display manager}. Its
21447 value must be a @code{lightdm-configuration} record, which is documented
21448 below. Among its distinguishing features are TigerVNC integration for
21449 easily remoting your desktop as well as support for the XDMCP protocol,
21450 which can be used by remote clients to start a session from the login
21453 In its most basic form, it can be used simply as:
21456 (service lightdm-service-type)
21459 A more elaborate example making use of the VNC capabilities and enabling
21460 more features and verbose logs could look like:
21463 (service lightdm-service-type
21464 (lightdm-configuration
21465 (allow-empty-passwords? #t)
21468 (vnc-server-command
21469 (file-append tigervnc-server "/bin/Xvnc"
21470 " -SecurityTypes None"))
21472 (list (lightdm-seat-configuration
21474 (user-session "ratpoison"))))))
21478 @c The LightDM service documentation can be auto-generated via the
21479 @c 'generate-doc' procedure at the bottom of the (gnu services lightdm)
21481 @c %start of fragment
21482 @deftp {Data Type} lightdm-configuration
21483 Available @code{lightdm-configuration} fields are:
21486 @item @code{lightdm} (default: @code{lightdm}) (type: file-like)
21487 The lightdm package to use.
21489 @item @code{allow-empty-passwords?} (default: @code{#f}) (type: boolean)
21490 Whether users not having a password set can login.
21492 @item @code{debug?} (default: @code{#f}) (type: boolean)
21493 Enable verbose output.
21495 @item @code{xorg-configuration} (type: xorg-configuration)
21496 The default Xorg server configuration to use to generate the Xorg server
21497 start script. It can be refined per seat via the @code{xserver-command}
21498 of the @code{<lightdm-seat-configuration>} record, if desired.
21500 @item @code{greeters} (type: list-of-greeter-configurations)
21501 The LightDM greeter configurations specifying the greeters to use.
21503 @item @code{seats} (type: list-of-seat-configurations)
21504 The seat configurations to use. A LightDM seat is akin to a user.
21506 @item @code{xdmcp?} (default: @code{#f}) (type: boolean)
21507 Whether a XDMCP server should listen on port UDP 177.
21509 @item @code{xdmcp-listen-address} (type: maybe-string)
21510 The host or IP address the XDMCP server listens for incoming
21511 connections. When unspecified, listen on for any hosts/IP addresses.
21513 @item @code{vnc-server?} (default: @code{#f}) (type: boolean)
21514 Whether a VNC server is started.
21516 @item @code{vnc-server-command} (type: file-like)
21517 The Xvnc command to use for the VNC server, it's possible to provide
21518 extra options not otherwise exposed along the command, for example to
21522 (vnc-server-command (file-append tigervnc-server "/bin/Xvnc"
21523 " -SecurityTypes None" ))
21526 Or to set a PasswordFile for the classic (unsecure) VncAuth
21530 (vnc-server-command (file-append tigervnc-server "/bin/Xvnc"
21531 " -PasswordFile /var/lib/lightdm/.vnc/passwd"))
21534 The password file should be manually created using the
21535 @command{vncpasswd} command. Note that LightDM will create new sessions
21536 for VNC users, which means they need to authenticate in the same way as
21539 @item @code{vnc-server-listen-address} (type: maybe-string)
21540 The host or IP address the VNC server listens for incoming connections.
21541 When unspecified, listen for any hosts/IP addresses.
21543 @item @code{vnc-server-port} (default: @code{5900}) (type: number)
21544 The TCP port the VNC server should listen to.
21546 @item @code{extra-config} (default: @code{()}) (type: list-of-strings)
21547 Extra configuration values to append to the LightDM configuration file.
21553 @c %end of fragment
21554 @c %start of fragment
21556 @deftp {Data Type} lightdm-gtk-greeter-configuration
21557 Available @code{lightdm-gtk-greeter-configuration} fields are:
21560 @item @code{lightdm-gtk-greeter} (default: @code{lightdm-gtk-greeter}) (type: file-like)
21561 The lightdm-gtk-greeter package to use.
21563 @item @code{assets} @
21564 (default: @code{(adwaita-icon-theme gnome-themes-extrahicolor-icon-theme)}) @
21565 (type: list-of-file-likes)
21566 The list of packages complementing the greeter, such as package
21567 providing icon themes.
21569 @item @code{theme-name} (default: @code{"Adwaita"}) (type: string)
21570 The name of the theme to use.
21572 @item @code{icon-theme-name} (default: @code{"Adwaita"}) (type: string)
21573 The name of the icon theme to use.
21575 @item @code{cursor-theme-name} (default: @code{"Adwaita"}) (type: string)
21576 The name of the cursor theme to use.
21578 @item @code{cursor-theme-size} (default: @code{16}) (type: number)
21579 The size to use for the the cursor theme.
21581 @item @code{allow-debugging?} (type: maybe-boolean)
21582 Set to #t to enable debug log level.
21584 @item @code{background} (type: file-like)
21585 The background image to use.
21587 @item @code{at-spi-enabled?} (default: @code{#f}) (type: boolean)
21588 Enable accessibility support through the Assistive Technology Service
21589 Provider Interface (AT-SPI).
21591 @item @code{a11y-states} @
21592 (default: @code{(contrast font keyboard reader)}) (type: list-of-a11y-states)
21593 The accessibility features to enable, given as list of symbols.
21595 @item @code{reader} (type: maybe-file-like)
21596 The command to use to launch a screen reader.
21598 @item @code{extra-config} (default: @code{()}) (type: list-of-strings)
21599 Extra configuration values to append to the LightDM GTK Greeter
21600 configuration file.
21605 @c %end of fragment
21606 @c %start of fragment
21608 @deftp {Data Type} lightdm-seat-configuration
21609 Available @code{lightdm-seat-configuration} fields are:
21612 @item @code{name} (type: seat-name)
21613 The name of the seat. An asterisk (*) can be used in the name to apply
21614 the seat configuration to all the seat names it matches.
21616 @item @code{user-session} (type: maybe-string)
21617 The session to use by default. The session name must be provided as a
21618 lowercase string, such as @code{"gnome"}, @code{"ratpoison"}, etc.
21620 @item @code{type} (default: @code{local}) (type: seat-type)
21621 The type of the seat, either the @code{local} or @code{xremote} symbol.
21623 @item @code{autologin-user} (type: maybe-string)
21624 The username to automatically log in with by default.
21626 @item @code{greeter-session} @
21627 (default: @code{lightdm-gtk-greeter}) (type: greeter-session)
21628 The greeter session to use, specified as a symbol. Currently, only
21629 @code{lightdm-gtk-greeter} is supported.
21631 @item @code{xserver-command} (type: maybe-file-like)
21632 The Xorg server command to run.
21634 @item @code{session-wrapper} (type: file-like)
21635 The xinitrc session wrapper to use.
21637 @item @code{extra-config} (default: @code{()}) (type: list-of-strings)
21638 Extra configuration values to append to the seat configuration section.
21642 @c %end of fragment
21645 @cindex Xorg, configuration
21646 @deftp {Data Type} xorg-configuration
21647 This data type represents the configuration of the Xorg graphical
21648 display server. Note that there is no Xorg service; instead, the X
21649 server is started by a ``display manager'' such as GDM, SDDM, LightDM or
21650 SLiM@. Thus, the configuration of these display managers aggregates an
21651 @code{xorg-configuration} record.
21654 @item @code{modules} (default: @code{%default-xorg-modules})
21655 This is a list of @dfn{module packages} loaded by the Xorg
21656 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
21658 @item @code{fonts} (default: @code{%default-xorg-fonts})
21659 This is a list of font directories to add to the server's @dfn{font path}.
21661 @item @code{drivers} (default: @code{'()})
21662 This must be either the empty list, in which case Xorg chooses a graphics
21663 driver automatically, or a list of driver names that will be tried in this
21664 order---e.g., @code{("modesetting" "vesa")}.
21666 @item @code{resolutions} (default: @code{'()})
21667 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
21668 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
21671 @cindex keyboard layout, for Xorg
21672 @cindex keymap, for Xorg
21673 @item @code{keyboard-layout} (default: @code{#f})
21674 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
21675 English (``qwerty'') for a 105-key PC keyboard.
21677 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
21678 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
21679 information on how to specify the keyboard layout.
21681 @item @code{extra-config} (default: @code{'()})
21682 This is a list of strings or objects appended to the configuration file. It
21683 is used to pass extra text to be added verbatim to the configuration file.
21685 @item @code{server} (default: @code{xorg-server})
21686 This is the package providing the Xorg server.
21688 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
21689 This is the list of command-line arguments to pass to the X server. The
21690 default is @code{-nolisten tcp}.
21694 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
21695 [@var{login-manager-service-type}]
21696 Tell the log-in manager (of type @var{login-manager-service-type}) to use
21697 @var{config}, an @code{<xorg-configuration>} record.
21699 Since the Xorg configuration is embedded in the log-in manager's
21700 configuration---e.g., @code{gdm-configuration}---this procedure provides a
21701 shorthand to set the Xorg configuration.
21704 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
21705 Return a @code{startx} script in which the modules, fonts, etc. specified
21706 in @var{config}, are available. The result should be used in place of
21709 Usually the X server is started by a login manager.
21713 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
21714 Add @var{package}, a package for a screen locker or screen saver whose
21715 command is @var{program}, to the set of setuid programs and add a PAM entry
21716 for it. For example:
21719 (screen-locker-service xlockmore "xlock")
21722 makes the good ol' XlockMore usable.
21726 @node Printing Services
21727 @subsection Printing Services
21729 @cindex printer support with CUPS
21730 The @code{(gnu services cups)} module provides a Guix service definition
21731 for the CUPS printing service. To add printer support to a Guix
21732 system, add a @code{cups-service} to the operating system definition:
21734 @deffn {Scheme Variable} cups-service-type
21735 The service type for the CUPS print server. Its value should be a valid
21736 CUPS configuration (see below). To use the default settings, simply
21739 (service cups-service-type)
21743 The CUPS configuration controls the basic things about your CUPS
21744 installation: what interfaces it listens on, what to do if a print job
21745 fails, how much logging to do, and so on. To actually add a printer,
21746 you have to visit the @url{http://localhost:631} URL, or use a tool such
21747 as GNOME's printer configuration services. By default, configuring a
21748 CUPS service will generate a self-signed certificate if needed, for
21749 secure connections to the print server.
21751 Suppose you want to enable the Web interface of CUPS and also add
21752 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
21753 package and for HP printers @i{via} the @code{hplip-minimal} package.
21754 You can do that directly, like this (you need to use the
21755 @code{(gnu packages cups)} module):
21758 (service cups-service-type
21759 (cups-configuration
21760 (web-interface? #t)
21762 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
21766 If you wish to use the Qt5 based GUI which comes with the hplip
21767 package then it is suggested that you install the @code{hplip} package,
21768 either in your OS configuration file or as your user.
21771 The available configuration parameters follow. Each parameter
21772 definition is preceded by its type; for example, @samp{string-list foo}
21773 indicates that the @code{foo} parameter should be specified as a list of
21774 strings. There is also a way to specify the configuration as a string,
21775 if you have an old @code{cupsd.conf} file that you want to port over
21776 from some other system; see the end for more details.
21778 @c The following documentation was initially generated by
21779 @c (generate-documentation) in (gnu services cups). Manually maintained
21780 @c documentation is better, so we shouldn't hesitate to edit below as
21781 @c needed. However if the change you want to make to this documentation
21782 @c can be done in an automated way, it's probably easier to change
21783 @c (generate-documentation) than to make it below and have to deal with
21784 @c the churn as CUPS updates.
21787 Available @code{cups-configuration} fields are:
21789 @deftypevr {@code{cups-configuration} parameter} package cups
21793 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
21794 Drivers and other extensions to the CUPS package.
21797 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
21798 Configuration of where to write logs, what directories to use for print
21799 spools, and related privileged configuration parameters.
21801 Available @code{files-configuration} fields are:
21803 @deftypevr {@code{files-configuration} parameter} log-location access-log
21804 Defines the access log filename. Specifying a blank filename disables
21805 access log generation. The value @code{stderr} causes log entries to be
21806 sent to the standard error file when the scheduler is running in the
21807 foreground, or to the system log daemon when run in the background. The
21808 value @code{syslog} causes log entries to be sent to the system log
21809 daemon. The server name may be included in filenames using the string
21810 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
21812 Defaults to @samp{"/var/log/cups/access_log"}.
21815 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
21816 Where CUPS should cache data.
21818 Defaults to @samp{"/var/cache/cups"}.
21821 @deftypevr {@code{files-configuration} parameter} string config-file-perm
21822 Specifies the permissions for all configuration files that the scheduler
21825 Note that the permissions for the printers.conf file are currently
21826 masked to only allow access from the scheduler user (typically root).
21827 This is done because printer device URIs sometimes contain sensitive
21828 authentication information that should not be generally known on the
21829 system. There is no way to disable this security feature.
21831 Defaults to @samp{"0640"}.
21834 @deftypevr {@code{files-configuration} parameter} log-location error-log
21835 Defines the error log filename. Specifying a blank filename disables
21836 error log generation. The value @code{stderr} causes log entries to be
21837 sent to the standard error file when the scheduler is running in the
21838 foreground, or to the system log daemon when run in the background. The
21839 value @code{syslog} causes log entries to be sent to the system log
21840 daemon. The server name may be included in filenames using the string
21841 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
21843 Defaults to @samp{"/var/log/cups/error_log"}.
21846 @deftypevr {@code{files-configuration} parameter} string fatal-errors
21847 Specifies which errors are fatal, causing the scheduler to exit. The
21852 No errors are fatal.
21855 All of the errors below are fatal.
21858 Browsing initialization errors are fatal, for example failed connections
21859 to the DNS-SD daemon.
21862 Configuration file syntax errors are fatal.
21865 Listen or Port errors are fatal, except for IPv6 failures on the
21866 loopback or @code{any} addresses.
21869 Log file creation or write errors are fatal.
21872 Bad startup file permissions are fatal, for example shared TLS
21873 certificate and key files with world-read permissions.
21876 Defaults to @samp{"all -browse"}.
21879 @deftypevr {@code{files-configuration} parameter} boolean file-device?
21880 Specifies whether the file pseudo-device can be used for new printer
21881 queues. The URI @uref{file:///dev/null} is always allowed.
21883 Defaults to @samp{#f}.
21886 @deftypevr {@code{files-configuration} parameter} string group
21887 Specifies the group name or ID that will be used when executing external
21890 Defaults to @samp{"lp"}.
21893 @deftypevr {@code{files-configuration} parameter} string log-file-group
21894 Specifies the group name or ID that will be used for log files.
21896 Defaults to @samp{"lpadmin"}.
21899 @deftypevr {@code{files-configuration} parameter} string log-file-perm
21900 Specifies the permissions for all log files that the scheduler writes.
21902 Defaults to @samp{"0644"}.
21905 @deftypevr {@code{files-configuration} parameter} log-location page-log
21906 Defines the page log filename. Specifying a blank filename disables
21907 page log generation. The value @code{stderr} causes log entries to be
21908 sent to the standard error file when the scheduler is running in the
21909 foreground, or to the system log daemon when run in the background. The
21910 value @code{syslog} causes log entries to be sent to the system log
21911 daemon. The server name may be included in filenames using the string
21912 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
21914 Defaults to @samp{"/var/log/cups/page_log"}.
21917 @deftypevr {@code{files-configuration} parameter} string remote-root
21918 Specifies the username that is associated with unauthenticated accesses
21919 by clients claiming to be the root user. The default is @code{remroot}.
21921 Defaults to @samp{"remroot"}.
21924 @deftypevr {@code{files-configuration} parameter} file-name request-root
21925 Specifies the directory that contains print jobs and other HTTP request
21928 Defaults to @samp{"/var/spool/cups"}.
21931 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
21932 Specifies the level of security sandboxing that is applied to print
21933 filters, backends, and other child processes of the scheduler; either
21934 @code{relaxed} or @code{strict}. This directive is currently only
21935 used/supported on macOS.
21937 Defaults to @samp{strict}.
21940 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
21941 Specifies the location of TLS certificates and private keys. CUPS will
21942 look for public and private keys in this directory: @file{.crt} files
21943 for PEM-encoded certificates and corresponding @file{.key} files for
21944 PEM-encoded private keys.
21946 Defaults to @samp{"/etc/cups/ssl"}.
21949 @deftypevr {@code{files-configuration} parameter} file-name server-root
21950 Specifies the directory containing the server configuration files.
21952 Defaults to @samp{"/etc/cups"}.
21955 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
21956 Specifies whether the scheduler calls fsync(2) after writing
21957 configuration or state files.
21959 Defaults to @samp{#f}.
21962 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
21963 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
21966 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
21967 Specifies the directory where temporary files are stored.
21969 Defaults to @samp{"/var/spool/cups/tmp"}.
21972 @deftypevr {@code{files-configuration} parameter} string user
21973 Specifies the user name or ID that is used when running external
21976 Defaults to @samp{"lp"}.
21979 @deftypevr {@code{files-configuration} parameter} string set-env
21980 Set the specified environment variable to be passed to child processes.
21982 Defaults to @samp{"variable value"}.
21986 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
21987 Specifies the logging level for the AccessLog file. The @code{config}
21988 level logs when printers and classes are added, deleted, or modified and
21989 when configuration files are accessed or updated. The @code{actions}
21990 level logs when print jobs are submitted, held, released, modified, or
21991 canceled, and any of the conditions for @code{config}. The @code{all}
21992 level logs all requests.
21994 Defaults to @samp{actions}.
21997 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
21998 Specifies whether to purge job history data automatically when it is no
21999 longer required for quotas.
22001 Defaults to @samp{#f}.
22004 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
22005 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
22006 For example, @samp{"_cups" "_print"} will tell network clients that both
22007 CUPS sharing and IPP Everywhere are supported.
22009 Defaults to @samp{"_cups"}.
22012 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
22013 Specifies which protocols to use for local printer sharing.
22015 Defaults to @samp{dnssd}.
22018 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
22019 Specifies whether the CUPS web interface is advertised.
22021 Defaults to @samp{#f}.
22024 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
22025 Specifies whether shared printers are advertised.
22027 Defaults to @samp{#f}.
22030 @deftypevr {@code{cups-configuration} parameter} string classification
22031 Specifies the security classification of the server. Any valid banner
22032 name can be used, including @samp{"classified"}, @samp{"confidential"},
22033 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
22034 banner can be omitted to disable secure printing functions.
22036 Defaults to @samp{""}.
22039 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
22040 Specifies whether users may override the classification (cover page) of
22041 individual print jobs using the @code{job-sheets} option.
22043 Defaults to @samp{#f}.
22046 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
22047 Specifies the default type of authentication to use.
22049 Defaults to @samp{Basic}.
22052 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
22053 Specifies whether encryption will be used for authenticated requests.
22055 Defaults to @samp{Required}.
22058 @deftypevr {@code{cups-configuration} parameter} string default-language
22059 Specifies the default language to use for text and web content.
22061 Defaults to @samp{"en"}.
22064 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
22065 Specifies the default paper size for new print queues. @samp{"Auto"}
22066 uses a locale-specific default, while @samp{"None"} specifies there is
22067 no default paper size. Specific size names are typically
22068 @samp{"Letter"} or @samp{"A4"}.
22070 Defaults to @samp{"Auto"}.
22073 @deftypevr {@code{cups-configuration} parameter} string default-policy
22074 Specifies the default access policy to use.
22076 Defaults to @samp{"default"}.
22079 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
22080 Specifies whether local printers are shared by default.
22082 Defaults to @samp{#t}.
22085 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
22086 Specifies the delay for updating of configuration and state files, in
22087 seconds. A value of 0 causes the update to happen as soon as possible,
22088 typically within a few milliseconds.
22090 Defaults to @samp{30}.
22093 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
22094 Specifies what to do when an error occurs. Possible values are
22095 @code{abort-job}, which will discard the failed print job;
22096 @code{retry-job}, which will retry the job at a later time;
22097 @code{retry-current-job}, which retries the failed job immediately; and
22098 @code{stop-printer}, which stops the printer.
22100 Defaults to @samp{stop-printer}.
22103 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
22104 Specifies the maximum cost of filters that are run concurrently, which
22105 can be used to minimize disk, memory, and CPU resource problems. A
22106 limit of 0 disables filter limiting. An average print to a
22107 non-PostScript printer needs a filter limit of about 200. A PostScript
22108 printer needs about half that (100). Setting the limit below these
22109 thresholds will effectively limit the scheduler to printing a single job
22112 Defaults to @samp{0}.
22115 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
22116 Specifies the scheduling priority of filters that are run to print a
22117 job. The nice value ranges from 0, the highest priority, to 19, the
22120 Defaults to @samp{0}.
22123 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
22124 Specifies whether to do reverse lookups on connecting clients. The
22125 @code{double} setting causes @code{cupsd} to verify that the hostname
22126 resolved from the address matches one of the addresses returned for that
22127 hostname. Double lookups also prevent clients with unregistered
22128 addresses from connecting to your server. Only set this option to
22129 @code{#t} or @code{double} if absolutely required.
22131 Defaults to @samp{#f}.
22134 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
22135 Specifies the number of seconds to wait before killing the filters and
22136 backend associated with a canceled or held job.
22138 Defaults to @samp{30}.
22141 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
22142 Specifies the interval between retries of jobs in seconds. This is
22143 typically used for fax queues but can also be used with normal print
22144 queues whose error policy is @code{retry-job} or
22145 @code{retry-current-job}.
22147 Defaults to @samp{30}.
22150 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
22151 Specifies the number of retries that are done for jobs. This is
22152 typically used for fax queues but can also be used with normal print
22153 queues whose error policy is @code{retry-job} or
22154 @code{retry-current-job}.
22156 Defaults to @samp{5}.
22159 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
22160 Specifies whether to support HTTP keep-alive connections.
22162 Defaults to @samp{#t}.
22165 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
22166 Specifies the maximum size of print files, IPP requests, and HTML form
22167 data. A limit of 0 disables the limit check.
22169 Defaults to @samp{0}.
22172 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
22173 Listens on the specified interfaces for connections. Valid values are
22174 of the form @var{address}:@var{port}, where @var{address} is either an
22175 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
22176 indicate all addresses. Values can also be file names of local UNIX
22177 domain sockets. The Listen directive is similar to the Port directive
22178 but allows you to restrict access to specific interfaces or networks.
22181 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
22182 Specifies the number of pending connections that will be allowed. This
22183 normally only affects very busy servers that have reached the MaxClients
22184 limit, but can also be triggered by large numbers of simultaneous
22185 connections. When the limit is reached, the operating system will
22186 refuse additional connections until the scheduler can accept the pending
22189 Defaults to @samp{128}.
22192 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
22193 Specifies a set of additional access controls.
22195 Available @code{location-access-controls} fields are:
22197 @deftypevr {@code{location-access-controls} parameter} file-name path
22198 Specifies the URI path to which the access control applies.
22201 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
22202 Access controls for all access to this path, in the same format as the
22203 @code{access-controls} of @code{operation-access-control}.
22205 Defaults to @samp{()}.
22208 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
22209 Access controls for method-specific access to this path.
22211 Defaults to @samp{()}.
22213 Available @code{method-access-controls} fields are:
22215 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
22216 If @code{#t}, apply access controls to all methods except the listed
22217 methods. Otherwise apply to only the listed methods.
22219 Defaults to @samp{#f}.
22222 @deftypevr {@code{method-access-controls} parameter} method-list methods
22223 Methods to which this access control applies.
22225 Defaults to @samp{()}.
22228 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
22229 Access control directives, as a list of strings. Each string should be
22230 one directive, such as @samp{"Order allow,deny"}.
22232 Defaults to @samp{()}.
22237 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
22238 Specifies the number of debugging messages that are retained for logging
22239 if an error occurs in a print job. Debug messages are logged regardless
22240 of the LogLevel setting.
22242 Defaults to @samp{100}.
22245 @deftypevr {@code{cups-configuration} parameter} log-level log-level
22246 Specifies the level of logging for the ErrorLog file. The value
22247 @code{none} stops all logging while @code{debug2} logs everything.
22249 Defaults to @samp{info}.
22252 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
22253 Specifies the format of the date and time in the log files. The value
22254 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
22256 Defaults to @samp{standard}.
22259 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
22260 Specifies the maximum number of simultaneous clients that are allowed by
22263 Defaults to @samp{100}.
22266 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
22267 Specifies the maximum number of simultaneous clients that are allowed
22268 from a single address.
22270 Defaults to @samp{100}.
22273 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
22274 Specifies the maximum number of copies that a user can print of each
22277 Defaults to @samp{9999}.
22280 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
22281 Specifies the maximum time a job may remain in the @code{indefinite}
22282 hold state before it is canceled. A value of 0 disables cancellation of
22285 Defaults to @samp{0}.
22288 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
22289 Specifies the maximum number of simultaneous jobs that are allowed. Set
22290 to 0 to allow an unlimited number of jobs.
22292 Defaults to @samp{500}.
22295 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
22296 Specifies the maximum number of simultaneous jobs that are allowed per
22297 printer. A value of 0 allows up to MaxJobs jobs per printer.
22299 Defaults to @samp{0}.
22302 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
22303 Specifies the maximum number of simultaneous jobs that are allowed per
22304 user. A value of 0 allows up to MaxJobs jobs per user.
22306 Defaults to @samp{0}.
22309 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
22310 Specifies the maximum time a job may take to print before it is
22311 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
22313 Defaults to @samp{10800}.
22316 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
22317 Specifies the maximum size of the log files before they are rotated, in
22318 bytes. The value 0 disables log rotation.
22320 Defaults to @samp{1048576}.
22323 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
22324 Specifies the maximum amount of time to allow between files in a
22325 multiple file print job, in seconds.
22327 Defaults to @samp{900}.
22330 @deftypevr {@code{cups-configuration} parameter} string page-log-format
22331 Specifies the format of PageLog lines. Sequences beginning with percent
22332 (@samp{%}) characters are replaced with the corresponding information,
22333 while all other characters are copied literally. The following percent
22334 sequences are recognized:
22338 insert a single percent character
22341 insert the value of the specified IPP attribute
22344 insert the number of copies for the current page
22347 insert the current page number
22350 insert the current date and time in common log format
22356 insert the printer name
22359 insert the username
22362 A value of the empty string disables page logging. The string @code{%p
22363 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
22364 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
22367 Defaults to @samp{""}.
22370 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
22371 Passes the specified environment variable(s) to child processes; a list
22374 Defaults to @samp{()}.
22377 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
22378 Specifies named access control policies.
22380 Available @code{policy-configuration} fields are:
22382 @deftypevr {@code{policy-configuration} parameter} string name
22383 Name of the policy.
22386 @deftypevr {@code{policy-configuration} parameter} string job-private-access
22387 Specifies an access list for a job's private values. @code{@@ACL} maps
22388 to the printer's requesting-user-name-allowed or
22389 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
22390 owner. @code{@@SYSTEM} maps to the groups listed for the
22391 @code{system-group} field of the @code{files-configuration},
22392 which is reified into the @code{cups-files.conf(5)} file. Other
22393 possible elements of the access list include specific user names, and
22394 @code{@@@var{group}} to indicate members of a specific group. The
22395 access list may also be simply @code{all} or @code{default}.
22397 Defaults to @samp{"@@OWNER @@SYSTEM"}.
22400 @deftypevr {@code{policy-configuration} parameter} string job-private-values
22401 Specifies the list of job values to make private, or @code{all},
22402 @code{default}, or @code{none}.
22404 Defaults to @samp{"job-name job-originating-host-name
22405 job-originating-user-name phone"}.
22408 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
22409 Specifies an access list for a subscription's private values.
22410 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
22411 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
22412 owner. @code{@@SYSTEM} maps to the groups listed for the
22413 @code{system-group} field of the @code{files-configuration},
22414 which is reified into the @code{cups-files.conf(5)} file. Other
22415 possible elements of the access list include specific user names, and
22416 @code{@@@var{group}} to indicate members of a specific group. The
22417 access list may also be simply @code{all} or @code{default}.
22419 Defaults to @samp{"@@OWNER @@SYSTEM"}.
22422 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
22423 Specifies the list of job values to make private, or @code{all},
22424 @code{default}, or @code{none}.
22426 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
22427 notify-subscriber-user-name notify-user-data"}.
22430 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
22431 Access control by IPP operation.
22433 Defaults to @samp{()}.
22437 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
22438 Specifies whether job files (documents) are preserved after a job is
22439 printed. If a numeric value is specified, job files are preserved for
22440 the indicated number of seconds after printing. Otherwise a boolean
22441 value applies indefinitely.
22443 Defaults to @samp{86400}.
22446 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
22447 Specifies whether the job history is preserved after a job is printed.
22448 If a numeric value is specified, the job history is preserved for the
22449 indicated number of seconds after printing. If @code{#t}, the job
22450 history is preserved until the MaxJobs limit is reached.
22452 Defaults to @samp{#t}.
22455 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
22456 Specifies the amount of time to wait for job completion before
22457 restarting the scheduler.
22459 Defaults to @samp{30}.
22462 @deftypevr {@code{cups-configuration} parameter} string rip-cache
22463 Specifies the maximum amount of memory to use when converting documents
22464 into bitmaps for a printer.
22466 Defaults to @samp{"128m"}.
22469 @deftypevr {@code{cups-configuration} parameter} string server-admin
22470 Specifies the email address of the server administrator.
22472 Defaults to @samp{"root@@localhost.localdomain"}.
22475 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
22476 The ServerAlias directive is used for HTTP Host header validation when
22477 clients connect to the scheduler from external interfaces. Using the
22478 special name @code{*} can expose your system to known browser-based DNS
22479 rebinding attacks, even when accessing sites through a firewall. If the
22480 auto-discovery of alternate names does not work, we recommend listing
22481 each alternate name with a ServerAlias directive instead of using
22484 Defaults to @samp{*}.
22487 @deftypevr {@code{cups-configuration} parameter} string server-name
22488 Specifies the fully-qualified host name of the server.
22490 Defaults to @samp{"localhost"}.
22493 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
22494 Specifies what information is included in the Server header of HTTP
22495 responses. @code{None} disables the Server header. @code{ProductOnly}
22496 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
22497 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
22498 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
22499 the output of the @code{uname} command. @code{Full} reports @code{CUPS
22500 2.0.0 (@var{uname}) IPP/2.0}.
22502 Defaults to @samp{Minimal}.
22505 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
22506 Listens on the specified interfaces for encrypted connections. Valid
22507 values are of the form @var{address}:@var{port}, where @var{address} is
22508 either an IPv6 address enclosed in brackets, an IPv4 address, or
22509 @code{*} to indicate all addresses.
22511 Defaults to @samp{()}.
22514 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
22515 Sets encryption options. By default, CUPS only supports encryption
22516 using TLS v1.0 or higher using known secure cipher suites. Security is
22517 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
22518 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
22519 suites, which are required for some older clients. The @code{AllowSSL3} option
22520 enables SSL v3.0, which is required for some older clients that do not support
22521 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
22522 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
22523 protocol version to TLS v1.1.
22525 Defaults to @samp{()}.
22528 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
22529 Specifies whether the scheduler requires clients to strictly adhere to
22530 the IPP specifications.
22532 Defaults to @samp{#f}.
22535 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
22536 Specifies the HTTP request timeout, in seconds.
22538 Defaults to @samp{900}.
22542 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
22543 Specifies whether the web interface is enabled.
22545 Defaults to @samp{#f}.
22548 At this point you're probably thinking ``oh dear, Guix manual, I like
22549 you but you can stop already with the configuration options''. Indeed.
22550 However, one more point: it could be that you have an existing
22551 @code{cupsd.conf} that you want to use. In that case, you can pass an
22552 @code{opaque-cups-configuration} as the configuration of a
22553 @code{cups-service-type}.
22555 Available @code{opaque-cups-configuration} fields are:
22557 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
22561 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
22562 The contents of the @code{cupsd.conf}, as a string.
22565 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
22566 The contents of the @code{cups-files.conf} file, as a string.
22569 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
22570 strings of the same name, you could instantiate a CUPS service like
22574 (service cups-service-type
22575 (opaque-cups-configuration
22576 (cupsd.conf cupsd.conf)
22577 (cups-files.conf cups-files.conf)))
22581 @node Desktop Services
22582 @subsection Desktop Services
22584 The @code{(gnu services desktop)} module provides services that are
22585 usually useful in the context of a ``desktop'' setup---that is, on a
22586 machine running a graphical display server, possibly with graphical user
22587 interfaces, etc. It also defines services that provide specific desktop
22588 environments like GNOME, Xfce or MATE.
22590 To simplify things, the module defines a variable containing the set of
22591 services that users typically expect on a machine with a graphical
22592 environment and networking:
22594 @defvr {Scheme Variable} %desktop-services
22595 This is a list of services that builds upon @code{%base-services} and
22596 adds or adjusts services for a typical ``desktop'' setup.
22598 In particular, it adds a graphical login manager (@pxref{X Window,
22599 @code{gdm-service-type}}), screen lockers, a network management tool
22600 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
22601 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
22602 energy and color management services, the @code{elogind} login and seat
22603 manager, the Polkit privilege service, the GeoClue location service, the
22604 AccountsService daemon that allows authorized users change system passwords,
22605 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
22606 name service switch service configured to be able to use @code{nss-mdns}
22607 (@pxref{Name Service Switch, mDNS}).
22610 The @code{%desktop-services} variable can be used as the @code{services}
22611 field of an @code{operating-system} declaration (@pxref{operating-system
22612 Reference, @code{services}}).
22614 Additionally, the @code{gnome-desktop-service-type},
22615 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
22616 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
22617 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
22618 ``add GNOME'' means that system-level services like the backlight adjustment
22619 helpers and the power management utilities are added to the system, extending
22620 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
22621 elevated privileges on a limited number of special-purpose system interfaces.
22622 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
22623 the GNOME metapackage to the system profile. Likewise, adding the Xfce
22624 service not only adds the @code{xfce} metapackage to the system profile, but
22625 it also gives the Thunar file manager the ability to open a ``root-mode'' file
22626 management window, if the user authenticates using the administrator's
22627 password via the standard polkit graphical interface. To ``add MATE'' means
22628 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
22629 to operate with elevated privileges on a limited number of special-purpose
22630 system interfaces. Additionally, adding a service of type
22631 @code{mate-desktop-service-type} adds the MATE metapackage to the system
22632 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
22633 appropriately, and several of Enlightenment's binaries are set as setuid,
22634 allowing Enlightenment's screen locker and other functionality to work as
22637 The desktop environments in Guix use the Xorg display server by
22638 default. If you'd like to use the newer display server protocol
22639 called Wayland, you need to enable Wayland support in GDM
22640 (@pxref{wayland-gdm}). Another solution is to use the
22641 @code{sddm-service} instead of GDM as the graphical login manager.
22642 You should then select the ``GNOME (Wayland)'' session in SDDM@.
22643 Alternatively you can also try starting GNOME on Wayland manually from a
22644 TTY with the command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
22645 gnome-session``. Currently only GNOME has support for Wayland.
22647 @defvr {Scheme Variable} gnome-desktop-service-type
22648 This is the type of the service that adds the @uref{https://www.gnome.org,
22649 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
22650 object (see below).
22652 This service adds the @code{gnome} package to the system profile, and extends
22653 polkit with the actions from @code{gnome-settings-daemon}.
22656 @deftp {Data Type} gnome-desktop-configuration
22657 Configuration record for the GNOME desktop environment.
22660 @item @code{gnome} (default: @code{gnome})
22661 The GNOME package to use.
22665 @defvr {Scheme Variable} xfce-desktop-service-type
22666 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
22667 desktop environment. Its value is an @code{xfce-desktop-configuration} object
22670 This service adds the @code{xfce} package to the system profile, and
22671 extends polkit with the ability for @code{thunar} to manipulate the file
22672 system as root from within a user session, after the user has authenticated
22673 with the administrator's password.
22675 Note that @code{xfce4-panel} and its plugin packages should be installed in
22676 the same profile to ensure compatibility. When using this service, you should
22677 add extra plugins (@code{xfce4-whiskermenu-plugin},
22678 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
22679 @code{operating-system}.
22682 @deftp {Data Type} xfce-desktop-configuration
22683 Configuration record for the Xfce desktop environment.
22686 @item @code{xfce} (default: @code{xfce})
22687 The Xfce package to use.
22691 @deffn {Scheme Variable} mate-desktop-service-type
22692 This is the type of the service that runs the @uref{https://mate-desktop.org/,
22693 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
22694 object (see below).
22696 This service adds the @code{mate} package to the system
22697 profile, and extends polkit with the actions from
22698 @code{mate-settings-daemon}.
22701 @deftp {Data Type} mate-desktop-configuration
22702 Configuration record for the MATE desktop environment.
22705 @item @code{mate} (default: @code{mate})
22706 The MATE package to use.
22710 @deffn {Scheme Variable} lxqt-desktop-service-type
22711 This is the type of the service that runs the @uref{https://lxqt-project.org,
22712 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
22713 object (see below).
22715 This service adds the @code{lxqt} package to the system
22719 @deftp {Data Type} lxqt-desktop-configuration
22720 Configuration record for the LXQt desktop environment.
22723 @item @code{lxqt} (default: @code{lxqt})
22724 The LXQT package to use.
22728 @deffn {Scheme Variable} enlightenment-desktop-service-type
22729 Return a service that adds the @code{enlightenment} package to the system
22730 profile, and extends dbus with actions from @code{efl}.
22733 @deftp {Data Type} enlightenment-desktop-service-configuration
22735 @item @code{enlightenment} (default: @code{enlightenment})
22736 The enlightenment package to use.
22740 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
22741 the default @code{%desktop-services} variable doesn't include any of
22742 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
22743 @code{%desktop-services} in the @code{services} field of your
22744 @code{operating-system}:
22747 (use-modules (gnu))
22748 (use-service-modules desktop)
22751 ;; cons* adds items to the list given as its last argument.
22752 (services (cons* (service gnome-desktop-service-type)
22753 (service xfce-desktop-service)
22754 %desktop-services))
22758 These desktop environments will then be available as options in the
22759 graphical login window.
22761 The actual service definitions included in @code{%desktop-services} and
22762 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
22763 are described below.
22765 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()] @
22767 Return a service that runs the ``system bus'', using @var{dbus}, with
22768 support for @var{services}. When @var{verbose?} is true, it causes the
22769 @samp{DBUS_VERBOSE} environment variable to be set to @samp{1}; a
22770 verbose-enabled D-Bus package such as @code{dbus-verbose} should be
22771 provided as @var{dbus} in this scenario. The verbose output is logged
22772 to @file{/var/log/dbus-daemon.log}.
22774 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
22775 facility. Its system bus is used to allow system services to communicate
22776 and to be notified of system-wide events.
22778 @var{services} must be a list of packages that provide an
22779 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
22780 and policy files. For example, to allow avahi-daemon to use the system bus,
22781 @var{services} must be equal to @code{(list avahi)}.
22784 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
22785 Return a service that runs the @code{elogind} login and
22786 seat management daemon. @uref{https://github.com/elogind/elogind,
22787 Elogind} exposes a D-Bus interface that can be used to know which users
22788 are logged in, know what kind of sessions they have open, suspend the
22789 system, inhibit system suspend, reboot the system, and other tasks.
22791 Elogind handles most system-level power events for a computer, for
22792 example suspending the system when a lid is closed, or shutting it down
22793 when the power button is pressed.
22795 The @var{config} keyword argument specifies the configuration for
22796 elogind, and should be the result of an @code{(elogind-configuration
22797 (@var{parameter} @var{value})...)} invocation. Available parameters and
22798 their default values are:
22801 @item kill-user-processes?
22803 @item kill-only-users
22805 @item kill-exclude-users
22807 @item inhibit-delay-max-seconds
22809 @item handle-power-key
22811 @item handle-suspend-key
22813 @item handle-hibernate-key
22815 @item handle-lid-switch
22817 @item handle-lid-switch-docked
22819 @item handle-lid-switch-external-power
22820 @code{*unspecified*}
22821 @item power-key-ignore-inhibited?
22823 @item suspend-key-ignore-inhibited?
22825 @item hibernate-key-ignore-inhibited?
22827 @item lid-switch-ignore-inhibited?
22829 @item holdoff-timeout-seconds
22833 @item idle-action-seconds
22835 @item runtime-directory-size-percent
22837 @item runtime-directory-size
22841 @item suspend-state
22842 @code{("mem" "standby" "freeze")}
22845 @item hibernate-state
22847 @item hibernate-mode
22848 @code{("platform" "shutdown")}
22849 @item hybrid-sleep-state
22851 @item hybrid-sleep-mode
22852 @code{("suspend" "platform" "shutdown")}
22856 @deffn {Scheme Procedure} accountsservice-service @
22857 [#:accountsservice @var{accountsservice}]
22858 Return a service that runs AccountsService, a system service that can
22859 list available accounts, change their passwords, and so on.
22860 AccountsService integrates with PolicyKit to enable unprivileged users
22861 to acquire the capability to modify their system configuration.
22862 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
22863 accountsservice web site} for more information.
22865 The @var{accountsservice} keyword argument is the @code{accountsservice}
22866 package to expose as a service.
22869 @deffn {Scheme Procedure} polkit-service @
22870 [#:polkit @var{polkit}]
22871 Return a service that runs the
22872 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
22873 management service}, which allows system administrators to grant access to
22874 privileged operations in a structured way. By querying the Polkit service, a
22875 privileged system component can know when it should grant additional
22876 capabilities to ordinary users. For example, an ordinary user can be granted
22877 the capability to suspend the system if the user is logged in locally.
22880 @defvr {Scheme Variable} polkit-wheel-service
22881 Service that adds the @code{wheel} group as admins to the Polkit
22882 service. This makes it so that users in the @code{wheel} group are queried
22883 for their own passwords when performing administrative actions instead of
22884 @code{root}'s, similar to the behaviour used by @code{sudo}.
22887 @defvr {Scheme Variable} upower-service-type
22888 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
22889 system-wide monitor for power consumption and battery levels, with the given
22890 configuration settings.
22892 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
22893 notably used by GNOME.
22896 @deftp {Data Type} upower-configuration
22897 Data type representation the configuration for UPower.
22901 @item @code{upower} (default: @var{upower})
22902 Package to use for @code{upower}.
22904 @item @code{watts-up-pro?} (default: @code{#f})
22905 Enable the Watts Up Pro device.
22907 @item @code{poll-batteries?} (default: @code{#t})
22908 Enable polling the kernel for battery level changes.
22910 @item @code{ignore-lid?} (default: @code{#f})
22911 Ignore the lid state, this can be useful if it's incorrect on a device.
22913 @item @code{use-percentage-for-policy?} (default: @code{#t})
22914 Whether a to use a policy based on battery percentage rather than on
22915 estimated time left. A policy based on battery percentage is usually
22918 @item @code{percentage-low} (default: @code{20})
22919 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
22920 at which the battery is considered low.
22922 @item @code{percentage-critical} (default: @code{5})
22923 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
22924 at which the battery is considered critical.
22926 @item @code{percentage-action} (default: @code{2})
22927 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
22928 at which action will be taken.
22930 @item @code{time-low} (default: @code{1200})
22931 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
22932 seconds at which the battery is considered low.
22934 @item @code{time-critical} (default: @code{300})
22935 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
22936 seconds at which the battery is considered critical.
22938 @item @code{time-action} (default: @code{120})
22939 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
22940 seconds at which action will be taken.
22942 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
22943 The action taken when @code{percentage-action} or @code{time-action} is
22944 reached (depending on the configuration of @code{use-percentage-for-policy?}).
22946 Possible values are:
22956 @code{'hybrid-sleep}.
22962 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
22963 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
22964 UDisks}, a @dfn{disk management} daemon that provides user interfaces
22965 with notifications and ways to mount/unmount disks. Programs that talk
22966 to UDisks include the @command{udisksctl} command, part of UDisks, and
22967 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
22968 it will only be able to use the file-system utilities installed in the
22969 system profile. For example if you want to be able to mount NTFS
22970 file-systems in read and write fashion, you'll need to have
22971 @code{ntfs-3g} installed system-wide.
22974 @deffn {Scheme Variable} colord-service-type
22975 This is the type of the service that runs @command{colord}, a system
22976 service with a D-Bus
22977 interface to manage the color profiles of input and output devices such as
22978 screens and scanners. It is notably used by the GNOME Color Manager graphical
22979 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
22980 site} for more information.
22983 @cindex scanner access
22984 @defvr {Scheme Variable} sane-service-type
22985 This service provides access to scanners @i{via}
22986 @uref{http://www.sane-project.org, SANE} by installing the necessary
22987 udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
22988 Services}) and relies by default on @code{sane-backends-minimal} package
22989 (see below) for hardware support.
22992 @defvr {Scheme Variable} sane-backends-minimal
22993 The default package which the @code{sane-service-type} installs. It
22994 supports many recent scanners.
22997 @defvr {Scheme Variable} sane-backends
22998 This package includes support for all scanners that
22999 @code{sane-backends-minimal} supports, plus older Hewlett-Packard
23000 scanners supported by @code{hplip} package. In order to use this on
23001 a system which relies on @code{%desktop-services}, you may use
23002 @code{modify-services} (@pxref{Service Reference,
23003 @code{modify-services}}) as illustrated below:
23006 (use-modules (gnu))
23007 (use-service-modules
23010 (use-package-modules
23014 (define %my-desktop-services
23015 ;; List of desktop services that supports a broader range of scanners.
23016 (modify-services %desktop-services
23017 (sane-service-type _ => sane-backends)))
23021 (services %my-desktop-services))
23025 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
23026 Return a configuration allowing an application to access GeoClue
23027 location data. @var{name} is the Desktop ID of the application, without
23028 the @code{.desktop} part. If @var{allowed?} is true, the application
23029 will have access to location information by default. The boolean
23030 @var{system?} value indicates whether an application is a system component
23031 or not. Finally @var{users} is a list of UIDs of all users for which
23032 this application is allowed location info access. An empty users list
23033 means that all users are allowed.
23036 @defvr {Scheme Variable} %standard-geoclue-applications
23037 The standard list of well-known GeoClue application configurations,
23038 granting authority to the GNOME date-and-time utility to ask for the
23039 current location in order to set the time zone, and allowing the
23040 IceCat and Epiphany web browsers to request location information.
23041 IceCat and Epiphany both query the user before allowing a web page to
23042 know the user's location.
23045 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
23046 [#:whitelist '()] @
23047 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
23048 [#:submit-data? #f]
23049 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
23050 [#:submission-nick "geoclue"] @
23051 [#:applications %standard-geoclue-applications]
23052 Return a service that runs the GeoClue location service. This service
23053 provides a D-Bus interface to allow applications to request access to a
23054 user's physical location, and optionally to add information to online
23055 location databases. See
23056 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
23057 web site} for more information.
23060 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
23061 [@w{#:auto-enable? #f}]
23062 Return a service that runs the @command{bluetoothd} daemon, which
23063 manages all the Bluetooth devices and provides a number of D-Bus
23064 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
23065 powered automatically at boot, which can be useful when using a
23066 bluetooth keyboard or mouse.
23068 Users need to be in the @code{lp} group to access the D-Bus service.
23071 @deffn {Scheme Variable} bluetooth-service-type
23072 This is the type for the @uref{https://bluez.org/, Linux Bluetooth Protocol
23073 Stack} (BlueZ) system, which generates the @file{/etc/bluetooth/main.conf}
23074 configuration file. The value for this type is a @command{bluetooth-configuration}
23075 record as in this example:
23078 (service bluetooth-service-type)
23081 See below for details about @code{bluetooth-configuration}.
23084 @deftp {Data Type} bluetooth-configuration
23085 Data type representing the configuration for @code{bluetooth-service}.
23088 @item @code{bluez} (default: @code{bluez})
23089 @code{bluez} package to use.
23091 @item @code{name} (default: @code{"BlueZ"})
23092 Default adapter name.
23094 @item @code{class} (default: @code{#x000000})
23095 Default device class. Only the major and minor device class bits are considered.
23097 @item @code{discoverable-timeout} (default: @code{180})
23098 How long to stay in discoverable mode before going back to non-discoverable. The
23099 value is in seconds.
23101 @item @code{always-pairable?} (default: @code{#f})
23102 Always allow pairing even if there are no agents registered.
23104 @item @code{pairable-timeout} (default: @code{0})
23105 How long to stay in pairable mode before going back to non-discoverable. The
23106 value is in seconds.
23108 @item @code{device-id} (default: @code{#f})
23109 Use vendor id source (assigner), vendor, product and version information for
23110 DID profile support. The values are separated by ":" and @var{assigner}, @var{VID},
23111 @var{PID} and @var{version}.
23113 Possible values are:
23117 @code{#f} to disable it,
23120 @code{"assigner:1234:5678:abcd"}, where @var{assigner} is either @code{usb} (default)
23121 or @code{bluetooth}.
23125 @item @code{reverse-service-discovery?} (default: @code{#t})
23126 Do reverse service discovery for previously unknown devices that connect to
23127 us. For BR/EDR this option is really only needed for qualification since the
23128 BITE tester doesn't like us doing reverse SDP for some test cases, for LE
23129 this disables the GATT client functionally so it can be used in system which
23130 can only operate as peripheral.
23132 @item @code{name-resolving?} (default: @code{#t})
23133 Enable name resolving after inquiry. Set it to @code{#f} if you don't need
23134 remote devices name and want shorter discovery cycle.
23136 @item @code{debug-keys?} (default: @code{#f})
23137 Enable runtime persistency of debug link keys. Default is false which makes
23138 debug link keys valid only for the duration of the connection that they were
23141 @item @code{controller-mode} (default: @code{'dual})
23142 Restricts all controllers to the specified transport. @code{'dual} means both
23143 BR/EDR and LE are enabled (if supported by the hardware).
23145 Possible values are:
23159 @item @code{multi-profile} (default: @code{'off})
23160 Enables Multi Profile Specification support. This allows to specify if system
23161 supports only Multiple Profiles Single Device (MPSD) configuration or both
23162 Multiple Profiles Single Device (MPSD) and Multiple Profiles Multiple Devices
23163 (MPMD) configurations.
23165 Possible values are:
23179 @item @code{fast-connectable?} (default: @code{#f})
23180 Permanently enables the Fast Connectable setting for adapters that support
23181 it. When enabled other devices can connect faster to us, however the
23182 tradeoff is increased power consumptions. This feature will fully work only
23183 on kernel version 4.1 and newer.
23185 @item @code{privacy} (default: @code{'off})
23186 Default privacy settings.
23190 @code{'off}: Disable local privacy
23193 @code{'network/on}: A device will only accept advertising packets from peer
23194 devices that contain private addresses. It may not be compatible with some
23195 legacy devices since it requires the use of RPA(s) all the time
23198 @code{'device}: A device in device privacy mode is only concerned about the
23199 privacy of the device and will accept advertising packets from peer devices
23200 that contain their Identity Address as well as ones that contain a private
23201 address, even if the peer device has distributed its IRK in the past
23205 and additionally, if @var{controller-mode} is set to @code{'dual}:
23209 @code{'limited-network}: Apply Limited Discoverable Mode to advertising, which
23210 follows the same policy as to BR/EDR that publishes the identity address when
23211 discoverable, and Network Privacy Mode for scanning
23214 @code{'limited-device}: Apply Limited Discoverable Mode to advertising, which
23215 follows the same policy as to BR/EDR that publishes the identity address when
23216 discoverable, and Device Privacy Mode for scanning.
23220 @item @code{just-works-repairing} (default: @code{'never})
23221 Specify the policy to the JUST-WORKS repairing initiated by peer.
23236 @item @code{temporary-timeout} (default: @code{30})
23237 How long to keep temporary devices around. The value is in seconds. @code{0}
23238 disables the timer completely.
23240 @item @code{refresh-discovery?} (default: @code{#t})
23241 Enables the device to issue an SDP request to update known services when
23242 profile is connected.
23244 @item @code{experimental} (default: @code{#f})
23245 Enables experimental features and interfaces, alternatively a list of UUIDs
23258 @code{(list (uuid <uuid-1>) (uuid <uuid-2>) ...)}.
23261 List of possible UUIDs:
23264 @code{d4992530-b9ec-469f-ab01-6c481c47da1c}: BlueZ Experimental Debug,
23267 @code{671b10b5-42c0-4696-9227-eb28d1b049d6}: BlueZ Experimental Simultaneous Central and Peripheral,
23270 @code{"15c0a148-c273-11ea-b3de-0242ac130004}: BlueZ Experimental LL privacy,
23273 @code{330859bc-7506-492d-9370-9a6f0614037f}: BlueZ Experimental Bluetooth Quality Report,
23276 @code{a6695ace-ee7f-4fb9-881a-5fac66c629af}: BlueZ Experimental Offload Codecs.
23279 @item @code{remote-name-request-retry-delay} (default: @code{300})
23280 The duration to avoid retrying to resolve a peer's name, if the previous
23283 @item @code{page-scan-type} (default: @code{#f})
23284 BR/EDR Page scan activity type.
23286 @item @code{page-scan-interval} (default: @code{#f})
23287 BR/EDR Page scan activity interval.
23289 @item @code{page-scan-window} (default: @code{#f})
23290 BR/EDR Page scan activity window.
23292 @item @code{inquiry-scan-type} (default: @code{#f})
23293 BR/EDR Inquiry scan activity type.
23295 @item @code{inquiry-scan-interval} (default: @code{#f})
23296 BR/EDR Inquiry scan activity interval.
23298 @item @code{inquiry-scan-window} (default: @code{#f})
23299 BR/EDR Inquiry scan activity window.
23301 @item @code{link-supervision-timeout} (default: @code{#f})
23302 BR/EDR Link supervision timeout.
23304 @item @code{page-timeout} (default: @code{#f})
23305 BR/EDR Page timeout.
23307 @item @code{min-sniff-interval} (default: @code{#f})
23308 BR/EDR minimum sniff interval.
23310 @item @code{max-sniff-interval} (default: @code{#f})
23311 BR/EDR maximum sniff interval.
23313 @item @code{min-advertisement-interval} (default: @code{#f})
23314 LE minimum advertisement interval (used for legacy advertisement only).
23316 @item @code{max-advertisement-interval} (default: @code{#f})
23317 LE maximum advertisement interval (used for legacy advertisement only).
23319 @item @code{multi-advertisement-rotation-interval} (default: @code{#f})
23320 LE multiple advertisement rotation interval.
23322 @item @code{scan-interval-auto-connect} (default: @code{#f})
23323 LE scanning interval used for passive scanning supporting auto connect.
23325 @item @code{scan-window-auto-connect} (default: @code{#f})
23326 LE scanning window used for passive scanning supporting auto connect.
23328 @item @code{scan-interval-suspend} (default: @code{#f})
23329 LE scanning interval used for active scanning supporting wake from suspend.
23331 @item @code{scan-window-suspend} (default: @code{#f})
23332 LE scanning window used for active scanning supporting wake from suspend.
23334 @item @code{scan-interval-discovery} (default: @code{#f})
23335 LE scanning interval used for active scanning supporting discovery.
23337 @item @code{scan-window-discovery} (default: @code{#f})
23338 LE scanning window used for active scanning supporting discovery.
23340 @item @code{scan-interval-adv-monitor} (default: @code{#f})
23341 LE scanning interval used for passive scanning supporting the advertisement monitor APIs.
23343 @item @code{scan-window-adv-monitor} (default: @code{#f})
23344 LE scanning window used for passive scanning supporting the advertisement monitor APIs.
23346 @item @code{scan-interval-connect} (default: @code{#f})
23347 LE scanning interval used for connection establishment.
23349 @item @code{scan-window-connect} (default: @code{#f})
23350 LE scanning window used for connection establishment.
23352 @item @code{min-connection-interval} (default: @code{#f})
23353 LE default minimum connection interval. This value is superseded by any specific
23354 value provided via the Load Connection Parameters interface.
23356 @item @code{max-connection-interval} (default: @code{#f})
23357 LE default maximum connection interval. This value is superseded by any specific
23358 value provided via the Load Connection Parameters interface.
23360 @item @code{connection-latency} (default: @code{#f})
23361 LE default connection latency. This value is superseded by any specific
23362 value provided via the Load Connection Parameters interface.
23364 @item @code{connection-supervision-timeout} (default: @code{#f})
23365 LE default connection supervision timeout. This value is superseded by any specific
23366 value provided via the Load Connection Parameters interface.
23368 @item @code{autoconnect-timeout} (default: @code{#f})
23369 LE default autoconnect timeout. This value is superseded by any specific
23370 value provided via the Load Connection Parameters interface.
23372 @item @code{adv-mon-allowlist-scan-duration} (default: @code{300})
23373 Allowlist scan duration during interleaving scan. Only used when scanning for ADV
23374 monitors. The units are msec.
23376 @item @code{adv-mon-no-filter-scan-duration} (default: @code{500})
23377 No filter scan duration during interleaving scan. Only used when scanning for ADV
23378 monitors. The units are msec.
23380 @item @code{enable-adv-mon-interleave-scan?} (default: @code{#t})
23381 Enable/Disable Advertisement Monitor interleave scan for power saving.
23383 @item @code{cache} (default: @code{'always})
23384 GATT attribute cache.
23386 Possible values are:
23389 @code{'always}: Always cache attributes even for devices not paired, this is
23390 recommended as it is best for interoperability, with more consistent
23391 reconnection times and enables proper tracking of notifications for all
23395 @code{'yes}: Only cache attributes of paired devices
23398 @code{'no}: Never cache attributes.
23401 @item @code{key-size} (default: @code{0})
23402 Minimum required Encryption Key Size for accessing secured characteristics.
23404 Possible values are:
23407 @code{0}: Don't care
23410 @code{7 <= N <= 16}
23413 @item @code{exchange-mtu} (default: @code{517})
23414 Exchange MTU size. Possible values are:
23418 @code{23 <= N <= 517}
23421 @item @code{att-channels} (default: @code{3})
23422 Number of ATT channels. Possible values are:
23426 @code{1}: Disables EATT
23432 @item @code{session-mode} (default: @code{'basic})
23433 AVDTP L2CAP signalling channel mode.
23435 Possible values are:
23439 @code{'basic}: Use L2CAP basic mode
23442 @code{'ertm}: Use L2CAP enhanced retransmission mode.
23445 @item @code{stream-mode} (default: @code{'basic})
23446 AVDTP L2CAP transport channel mode.
23448 Possible values are:
23452 @code{'basic}: Use L2CAP basic mode
23455 @code{'streaming}: Use L2CAP streaming mode.
23458 @item @code{reconnect-uuids} (default: @code{'()})
23459 The ReconnectUUIDs defines the set of remote services that should try
23460 to be reconnected to in case of a link loss (link supervision
23461 timeout). The policy plugin should contain a sane set of values by
23462 default, but this list can be overridden here. By setting the list to
23463 empty the reconnection feature gets disabled.
23472 @code{(list (uuid <uuid-1>) (uuid <uuid-2>) ...)}.
23475 @item @code{reconnect-attempts} (default: @code{7})
23476 Defines the number of attempts to reconnect after a link lost. Setting
23477 the value to 0 disables reconnecting feature.
23479 @item @code{reconnect-intervals} (default: @code{'(1 2 4 8 16 32 64)})
23480 Defines a list of intervals in seconds to use in between attempts. If
23481 the number of attempts defined in @var{reconnect-attempts} is bigger than
23482 the list of intervals the last interval is repeated until the last attempt.
23484 @item @code{auto-enable?} (default: @code{#f})
23485 Defines option to enable all controllers when they are found. This includes
23486 adapters present on start as well as adapters that are plugged in later on.
23488 @item @code{resume-delay} (default: @code{2})
23489 Audio devices that were disconnected due to suspend will be reconnected on
23490 resume. @var{resume-delay} determines the delay between when the controller
23491 resumes from suspend and a connection attempt is made. A longer delay is
23492 better for better co-existence with Wi-Fi. The value is in seconds.
23494 @item @code{rssi-sampling-period} (default: @code{#xFF})
23495 Default RSSI Sampling Period. This is used when a client registers an
23496 advertisement monitor and leaves the RSSISamplingPeriod unset.
23498 Possible values are:
23501 @code{#x0}: Report all advertisements
23504 @code{N = #xXX}: Report advertisements every N x 100 msec (range: #x01 to #xFE)
23507 @code{#xFF}: Report only one advertisement per device during monitoring period.
23513 @defvr {Scheme Variable} gnome-keyring-service-type
23514 This is the type of the service that adds the
23515 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
23516 value is a @code{gnome-keyring-configuration} object (see below).
23518 This service adds the @code{gnome-keyring} package to the system profile
23519 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
23520 a user's login keyring when they log in or setting its password with passwd.
23523 @deftp {Data Type} gnome-keyring-configuration
23524 Configuration record for the GNOME Keyring service.
23527 @item @code{keyring} (default: @code{gnome-keyring})
23528 The GNOME keyring package to use.
23530 @item @code{pam-services}
23531 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
23532 services to extend, where @var{service} is the name of an existing
23533 service to extend and @var{kind} is one of @code{login} or
23536 If @code{login} is given, it adds an optional
23537 @code{pam_gnome_keyring.so} to the auth block without arguments and to
23538 the session block with @code{auto_start}. If @code{passwd} is given, it
23539 adds an optional @code{pam_gnome_keyring.so} to the password block
23542 By default, this field contains ``gdm-password'' with the value @code{login}
23543 and ``passwd'' is with the value @code{passwd}.
23547 @defvr {Scheme Variable} seatd-service-type
23548 @uref{https://sr.ht/~kennylevinsen/seatd/, seatd} is a minimal seat
23551 Seat management takes care of mediating access to shared devices (graphics,
23552 input), without requiring the applications needing access to be root.
23557 ;; make sure seatd is running
23558 (service seatd-service-type))
23560 ;; normally one would want %base-services
23565 @code{seatd} operates over a UNIX domain socket, with @code{libseat}
23566 providing the client side of the protocol. Applications that acquire
23567 access to the shared resources via @code{seatd} (e.g. @code{sway})
23568 need to be able to talk to this socket.
23569 This can be achieved by adding the user they run under to the group
23570 owning @code{seatd}'s socket (usually ``seat''), like so:
23576 (supplementary-groups '("wheel" ; allow use of sudo, etc.
23577 "seat" ; seat management
23578 "audio" ; sound card
23579 "video" ; video devices such as webcams
23580 "cdrom")) ; the good ol' CD-ROM
23581 (comment "Bob's sister"))
23584 Depending on your setup, you will have to not only add regular users,
23585 but also system users to this group. For instance, some greetd greeters
23586 require graphics and therefore also need to negotiate with seatd.
23590 @deftp {Data Type} seatd-configuration
23591 Configuration record for the seatd daemon service.
23594 @item @code{seatd} (default: @code{seatd})
23595 The seatd package to use.
23597 @item @code{group} (default: @samp{"seat"})
23598 Group to own the seatd socket.
23600 @item @code{socket} (default: @samp{"/run/seatd.sock"})
23601 Where to create the seatd socket.
23603 @item @code{logfile} (default: @samp{"/var/log/seatd.log"})
23604 Log file to write to.
23606 @item @code{loglevel} (default: @samp{"error"})
23607 Log level to output logs. Possible values: @samp{"silent"}, @samp{"error"},
23608 @samp{"info"} and @samp{"debug"}.
23614 @node Sound Services
23615 @subsection Sound Services
23617 @cindex sound support
23619 @cindex PulseAudio, sound support
23621 The @code{(gnu services sound)} module provides a service to configure the
23622 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
23623 preferred ALSA output driver.
23625 @deffn {Scheme Variable} alsa-service-type
23626 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
23627 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
23628 configuration file. The value for this type is a @command{alsa-configuration}
23629 record as in this example:
23632 (service alsa-service-type)
23635 See below for details about @code{alsa-configuration}.
23638 @deftp {Data Type} alsa-configuration
23639 Data type representing the configuration for @code{alsa-service}.
23642 @item @code{alsa-plugins} (default: @var{alsa-plugins})
23643 @code{alsa-plugins} package to use.
23645 @item @code{pulseaudio?} (default: @var{#t})
23646 Whether ALSA applications should transparently be made to use the
23647 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
23649 Using PulseAudio allows you to run several sound-producing applications
23650 at the same time and to individual control them @i{via}
23651 @command{pavucontrol}, among other things.
23653 @item @code{extra-options} (default: @var{""})
23654 String to append to the @file{/etc/asound.conf} file.
23659 Individual users who want to override the system configuration of ALSA can do
23660 it with the @file{~/.asoundrc} file:
23663 # In guix, we have to specify the absolute path for plugins.
23665 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
23668 # Routing ALSA to jack:
23669 # <http://jackaudio.org/faq/routing_alsa.html>.
23673 0 system:playback_1
23674 1 system:playback_2
23691 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
23694 @deffn {Scheme Variable} pulseaudio-service-type
23695 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
23696 sound server. It exists to allow system overrides of the default settings
23697 via @code{pulseaudio-configuration}, see below.
23700 This service overrides per-user configuration files. If you want
23701 PulseAudio to honor configuration files in @file{~/.config/pulse} you
23702 have to unset the environment variables @env{PULSE_CONFIG} and
23703 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
23707 This service on its own does not ensure, that the @code{pulseaudio} package
23708 exists on your machine. It merely adds configuration files for it, as
23709 detailed below. In the (admittedly unlikely) case, that you find yourself
23710 without a @code{pulseaudio} package, consider enabling it through the
23711 @code{alsa-service-type} above.
23715 @deftp {Data Type} pulseaudio-configuration
23716 Data type representing the configuration for @code{pulseaudio-service}.
23719 @item @code{client-conf} (default: @code{'()})
23720 List of settings to set in @file{client.conf}.
23721 Accepts a list of strings or symbol-value pairs. A string will be
23722 inserted as-is with a newline added. A pair will be formatted as
23723 ``key = value'', again with a newline added.
23725 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
23726 List of settings to set in @file{daemon.conf}, formatted just like
23729 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
23730 Script file to use as @file{default.pa}. In case the
23731 @code{extra-script-files} field below is used, an @code{.include}
23732 directive pointing to @file{/etc/pulse/default.pa.d} is appended to the
23735 @item @code{extra-script-files} (default: @code{'()})
23736 A list of file-like objects defining extra PulseAudio scripts to run at
23737 the initialization of the @command{pulseaudio} daemon, after the main
23738 @code{script-file}. The scripts are deployed to the
23739 @file{/etc/pulse/default.pa.d} directory; they should have the
23740 @samp{.pa} file name extension. For a reference of the available
23741 commands, refer to @command{man pulse-cli-syntax}.
23743 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
23744 Script file to use as @file{system.pa}.
23747 The example below sets the default PulseAudio card profile, the default
23748 sink and the default source to use for a old SoundBlaster Audigy sound
23751 (pulseaudio-configuration
23752 (extra-script-files
23753 (list (plain-file "audigy.pa"
23755 set-card-profile alsa_card.pci-0000_01_01.0 \
23756 output:analog-surround-40+input:analog-mono
23757 set-default-source alsa_input.pci-0000_01_01.0.analog-mono
23758 set-default-sink alsa_output.pci-0000_01_01.0.analog-surround-40\n")))))
23761 Note that @code{pulseaudio-service-type} is part of
23762 @code{%desktop-services}; if your operating system declaration was
23763 derived from one of the desktop templates, you'll want to adjust the
23764 above example to modify the existing @code{pulseaudio-service-type} via
23765 @code{modify-services} (@pxref{Service Reference,
23766 @code{modify-services}}), instead of defining a new one.
23770 @deffn {Scheme Variable} ladspa-service-type
23771 This service sets the @var{LADSPA_PATH} variable, so that programs, which
23772 respect it, e.g. PulseAudio, can load LADSPA plugins.
23774 The following example will setup the service to enable modules from the
23775 @code{swh-plugins} package:
23778 (service ladspa-service-type
23779 (ladspa-configuration (plugins (list swh-plugins))))
23782 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
23787 @node Database Services
23788 @subsection Database Services
23792 The @code{(gnu services databases)} module provides the following services.
23794 @subsubheading PostgreSQL
23796 The following example describes a PostgreSQL service with the default
23800 (service postgresql-service-type
23801 (postgresql-configuration
23802 (postgresql postgresql-10)))
23805 If the services fails to start, it may be due to an incompatible
23806 cluster already present in @var{data-directory}. Adjust it (or, if you
23807 don't need the cluster anymore, delete @var{data-directory}), then
23808 restart the service.
23810 Peer authentication is used by default and the @code{postgres} user
23811 account has no shell, which prevents the direct execution of @code{psql}
23812 commands as this user. To use @code{psql}, you can temporarily log in
23813 as @code{postgres} using a shell, create a PostgreSQL superuser with the
23814 same name as one of the system users and then create the associated
23818 sudo -u postgres -s /bin/sh
23819 createuser --interactive
23820 createdb $MY_USER_LOGIN # Replace appropriately.
23823 @deftp {Data Type} postgresql-configuration
23824 Data type representing the configuration for the
23825 @code{postgresql-service-type}.
23828 @item @code{postgresql}
23829 PostgreSQL package to use for the service.
23831 @item @code{port} (default: @code{5432})
23832 Port on which PostgreSQL should listen.
23834 @item @code{locale} (default: @code{"en_US.utf8"})
23835 Locale to use as the default when creating the database cluster.
23837 @item @code{config-file} (default: @code{(postgresql-config-file)})
23838 The configuration file to use when running PostgreSQL@. The default
23839 behaviour uses the postgresql-config-file record with the default values
23842 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
23843 The directory where @command{pg_ctl} output will be written in a file
23844 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
23845 configuration errors for instance.
23847 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
23848 Directory in which to store the data.
23850 @item @code{extension-packages} (default: @code{'()})
23851 @cindex postgresql extension-packages
23852 Additional extensions are loaded from packages listed in
23853 @var{extension-packages}. Extensions are available at runtime. For instance,
23854 to create a geographic database using the @code{postgis} extension, a user can
23855 configure the postgresql-service as in this example:
23859 (use-package-modules databases geo)
23863 ;; postgresql is required to run `psql' but postgis is not required for
23864 ;; proper operation.
23865 (packages (cons* postgresql %base-packages))
23868 (service postgresql-service-type
23869 (postgresql-configuration
23870 (postgresql postgresql-10)
23871 (extension-packages (list postgis))))
23875 Then the extension becomes visible and you can initialise an empty geographic
23876 database in this way:
23880 > create database postgistest;
23881 > \connect postgistest;
23882 > create extension postgis;
23883 > create extension postgis_topology;
23886 There is no need to add this field for contrib extensions such as hstore or
23887 dblink as they are already loadable by postgresql. This field is only
23888 required to add extensions provided by other packages.
23893 @deftp {Data Type} postgresql-config-file
23894 Data type representing the PostgreSQL configuration file. As shown in
23895 the following example, this can be used to customize the configuration
23896 of PostgreSQL@. Note that you can use any G-expression or filename in
23897 place of this record, if you already have a configuration file you'd
23898 like to use for example.
23901 (service postgresql-service-type
23902 (postgresql-configuration
23904 (postgresql-config-file
23905 (log-destination "stderr")
23907 (plain-file "pg_hba.conf"
23909 local all all trust
23910 host all all 127.0.0.1/32 md5
23911 host all all ::1/128 md5"))
23913 '(("session_preload_libraries" "auto_explain")
23914 ("random_page_cost" 2)
23915 ("auto_explain.log_min_duration" "100 ms")
23916 ("work_mem" "500 MB")
23917 ("logging_collector" #t)
23918 ("log_directory" "/var/log/postgresql")))))))
23922 @item @code{log-destination} (default: @code{"syslog"})
23923 The logging method to use for PostgreSQL@. Multiple values are accepted,
23924 separated by commas.
23926 @item @code{hba-file} (default: @code{%default-postgres-hba})
23927 Filename or G-expression for the host-based authentication
23930 @item @code{ident-file} (default: @code{%default-postgres-ident})
23931 Filename or G-expression for the user name mapping configuration.
23933 @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
23934 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
23935 is to listen for connections from client applications. If set to
23936 @code{""} PostgreSQL does not listen on any Unix-domain sockets, in
23937 which case only TCP/IP sockets can be used to connect to the server.
23939 By default, the @code{#false} value means the PostgreSQL default value
23940 will be used, which is currently @samp{/tmp}.
23942 @item @code{extra-config} (default: @code{'()})
23943 List of additional keys and values to include in the PostgreSQL config
23944 file. Each entry in the list should be a list where the first element
23945 is the key, and the remaining elements are the values.
23947 The values can be numbers, booleans or strings and will be mapped to
23948 PostgreSQL parameters types @code{Boolean}, @code{String},
23949 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
23950 @uref{https://www.postgresql.org/docs/current/config-setting.html,
23956 @deffn {Scheme Variable} postgresql-role-service-type
23957 This service allows to create PostgreSQL roles and databases after
23958 PostgreSQL service start. Here is an example of its use.
23961 (service postgresql-role-service-type
23962 (postgresql-role-configuration
23964 (list (postgresql-role
23966 (create-database? #t))))))
23969 This service can be extended with extra roles, as in this
23973 (service-extension postgresql-role-service-type
23974 (const (postgresql-role
23976 (create-database? #t))))
23980 @deftp {Data Type} postgresql-role
23981 PostgreSQL manages database access permissions using the concept of
23982 roles. A role can be thought of as either a database user, or a group
23983 of database users, depending on how the role is set up. Roles can own
23984 database objects (for example, tables) and can assign privileges on
23985 those objects to other roles to control who has access to which objects.
23991 @item @code{permissions} (default: @code{'(createdb login)})
23992 The role permissions list. Supported permissions are @code{bypassrls},
23993 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
23996 @item @code{create-database?} (default: @code{#f})
23997 Whether to create a database with the same name as the role.
24002 @deftp {Data Type} postgresql-role-configuration
24003 Data type representing the configuration of
24004 @var{postgresql-role-service-type}.
24007 @item @code{host} (default: @code{"/var/run/postgresql"})
24008 The PostgreSQL host to connect to.
24010 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
24011 File name of the log file.
24013 @item @code{roles} (default: @code{'()})
24014 The initial PostgreSQL roles to create.
24018 @subsubheading MariaDB/MySQL
24020 @defvr {Scheme Variable} mysql-service-type
24021 This is the service type for a MySQL or MariaDB database server. Its value
24022 is a @code{mysql-configuration} object that specifies which package to use,
24023 as well as various settings for the @command{mysqld} daemon.
24026 @deftp {Data Type} mysql-configuration
24027 Data type representing the configuration of @var{mysql-service-type}.
24030 @item @code{mysql} (default: @var{mariadb})
24031 Package object of the MySQL database server, can be either @var{mariadb}
24034 For MySQL, a temporary root password will be displayed at activation time.
24035 For MariaDB, the root password is empty.
24037 @item @code{bind-address} (default: @code{"127.0.0.1"})
24038 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
24039 to bind to all available network interfaces.
24041 @item @code{port} (default: @code{3306})
24042 TCP port on which the database server listens for incoming connections.
24044 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
24045 Socket file to use for local (non-network) connections.
24047 @item @code{extra-content} (default: @code{""})
24048 Additional settings for the @file{my.cnf} configuration file.
24050 @item @code{extra-environment} (default: @code{#~'()})
24051 List of environment variables passed to the @command{mysqld} process.
24053 @item @code{auto-upgrade?} (default: @code{#t})
24054 Whether to automatically run @command{mysql_upgrade} after starting the
24055 service. This is necessary to upgrade the @dfn{system schema} after
24056 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
24057 be disabled if you would rather do that manually.
24062 @subsubheading Memcached
24064 @defvr {Scheme Variable} memcached-service-type
24065 This is the service type for the @uref{https://memcached.org/,
24066 Memcached} service, which provides a distributed in memory cache. The
24067 value for the service type is a @code{memcached-configuration} object.
24071 (service memcached-service-type)
24074 @deftp {Data Type} memcached-configuration
24075 Data type representing the configuration of memcached.
24078 @item @code{memcached} (default: @code{memcached})
24079 The Memcached package to use.
24081 @item @code{interfaces} (default: @code{'("0.0.0.0")})
24082 Network interfaces on which to listen.
24084 @item @code{tcp-port} (default: @code{11211})
24085 Port on which to accept connections.
24087 @item @code{udp-port} (default: @code{11211})
24088 Port on which to accept UDP connections on, a value of 0 will disable
24089 listening on a UDP socket.
24091 @item @code{additional-options} (default: @code{'()})
24092 Additional command line options to pass to @code{memcached}.
24096 @subsubheading Redis
24098 @defvr {Scheme Variable} redis-service-type
24099 This is the service type for the @uref{https://redis.io/, Redis}
24100 key/value store, whose value is a @code{redis-configuration} object.
24103 @deftp {Data Type} redis-configuration
24104 Data type representing the configuration of redis.
24107 @item @code{redis} (default: @code{redis})
24108 The Redis package to use.
24110 @item @code{bind} (default: @code{"127.0.0.1"})
24111 Network interface on which to listen.
24113 @item @code{port} (default: @code{6379})
24114 Port on which to accept connections on, a value of 0 will disable
24115 listening on a TCP socket.
24117 @item @code{working-directory} (default: @code{"/var/lib/redis"})
24118 Directory in which to store the database and related files.
24122 @node Mail Services
24123 @subsection Mail Services
24127 The @code{(gnu services mail)} module provides Guix service definitions
24128 for email services: IMAP, POP3, and LMTP servers, as well as mail
24129 transport agents (MTAs). Lots of acronyms! These services are detailed
24130 in the subsections below.
24132 @subsubheading Dovecot Service
24134 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
24135 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
24138 By default, Dovecot does not need much configuration; the default
24139 configuration object created by @code{(dovecot-configuration)} will
24140 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
24141 certificate will be generated for TLS-protected connections, though
24142 Dovecot will also listen on cleartext ports by default. There are a
24143 number of options, though, which mail administrators might need to change,
24144 and as is the case with other services, Guix allows the system
24145 administrator to specify these parameters via a uniform Scheme interface.
24147 For example, to specify that mail is located at @code{maildir~/.mail},
24148 one would instantiate the Dovecot service like this:
24151 (dovecot-service #:config
24152 (dovecot-configuration
24153 (mail-location "maildir:~/.mail")))
24156 The available configuration parameters follow. Each parameter
24157 definition is preceded by its type; for example, @samp{string-list foo}
24158 indicates that the @code{foo} parameter should be specified as a list of
24159 strings. There is also a way to specify the configuration as a string,
24160 if you have an old @code{dovecot.conf} file that you want to port over
24161 from some other system; see the end for more details.
24163 @c The following documentation was initially generated by
24164 @c (generate-documentation) in (gnu services mail). Manually maintained
24165 @c documentation is better, so we shouldn't hesitate to edit below as
24166 @c needed. However if the change you want to make to this documentation
24167 @c can be done in an automated way, it's probably easier to change
24168 @c (generate-documentation) than to make it below and have to deal with
24169 @c the churn as dovecot updates.
24171 Available @code{dovecot-configuration} fields are:
24173 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
24174 The dovecot package.
24177 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
24178 A list of IPs or hosts where to listen for connections. @samp{*}
24179 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
24180 interfaces. If you want to specify non-default ports or anything more
24181 complex, customize the address and port fields of the
24182 @samp{inet-listener} of the specific services you are interested in.
24185 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
24186 List of protocols we want to serve. Available protocols include
24187 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
24189 Available @code{protocol-configuration} fields are:
24191 @deftypevr {@code{protocol-configuration} parameter} string name
24192 The name of the protocol.
24195 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
24196 UNIX socket path to the master authentication server to find users.
24197 This is used by imap (for shared users) and lda.
24198 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
24201 @deftypevr {@code{protocol-configuration} parameter} boolean imap-metadata?
24202 Whether to enable the @code{IMAP METADATA} extension as defined in
24203 @uref{https://tools.ietf.org/html/rfc5464,RFC@tie{}5464}, which provides
24204 a means for clients to set and retrieve per-mailbox, per-user metadata
24205 and annotations over IMAP.
24207 If this is @samp{#t}, you must also specify a dictionary @i{via} the
24208 @code{mail-attribute-dict} setting.
24210 Defaults to @samp{#f}.
24214 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list managesieve-notify-capabilities
24215 Which NOTIFY capabilities to report to clients that first connect to
24216 the ManageSieve service, before authentication. These may differ from the
24217 capabilities offered to authenticated users. If this field is left empty,
24218 report what the Sieve interpreter supports by default.
24220 Defaults to @samp{()}.
24223 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list managesieve-sieve-capability
24224 Which SIEVE capabilities to report to clients that first connect to
24225 the ManageSieve service, before authentication. These may differ from the
24226 capabilities offered to authenticated users. If this field is left empty,
24227 report what the Sieve interpreter supports by default.
24229 Defaults to @samp{()}.
24233 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
24234 Space separated list of plugins to load.
24237 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
24238 Maximum number of IMAP connections allowed for a user from each IP
24239 address. NOTE: The username is compared case-sensitively.
24240 Defaults to @samp{10}.
24245 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
24246 List of services to enable. Available services include @samp{imap},
24247 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
24250 Available @code{service-configuration} fields are:
24252 @deftypevr {@code{service-configuration} parameter} string kind
24253 The service kind. Valid values include @code{director},
24254 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
24255 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
24256 @code{tcpwrap}, @code{quota-warning}, or anything else.
24259 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
24260 Listeners for the service. A listener is either a
24261 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
24262 an @code{inet-listener-configuration}.
24263 Defaults to @samp{()}.
24265 Available @code{unix-listener-configuration} fields are:
24267 @deftypevr {@code{unix-listener-configuration} parameter} string path
24268 Path to the file, relative to @code{base-dir} field. This is also used as
24272 @deftypevr {@code{unix-listener-configuration} parameter} string mode
24273 The access mode for the socket.
24274 Defaults to @samp{"0600"}.
24277 @deftypevr {@code{unix-listener-configuration} parameter} string user
24278 The user to own the socket.
24279 Defaults to @samp{""}.
24282 @deftypevr {@code{unix-listener-configuration} parameter} string group
24283 The group to own the socket.
24284 Defaults to @samp{""}.
24288 Available @code{fifo-listener-configuration} fields are:
24290 @deftypevr {@code{fifo-listener-configuration} parameter} string path
24291 Path to the file, relative to @code{base-dir} field. This is also used as
24295 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
24296 The access mode for the socket.
24297 Defaults to @samp{"0600"}.
24300 @deftypevr {@code{fifo-listener-configuration} parameter} string user
24301 The user to own the socket.
24302 Defaults to @samp{""}.
24305 @deftypevr {@code{fifo-listener-configuration} parameter} string group
24306 The group to own the socket.
24307 Defaults to @samp{""}.
24311 Available @code{inet-listener-configuration} fields are:
24313 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
24314 The protocol to listen for.
24317 @deftypevr {@code{inet-listener-configuration} parameter} string address
24318 The address on which to listen, or empty for all addresses.
24319 Defaults to @samp{""}.
24322 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
24323 The port on which to listen.
24326 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
24327 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
24329 Defaults to @samp{#t}.
24334 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
24335 Maximum number of simultaneous client connections per process. Once
24336 this number of connections is received, the next incoming connection
24337 will prompt Dovecot to spawn another process. If set to 0,
24338 @code{default-client-limit} is used instead.
24340 Defaults to @samp{0}.
24344 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
24345 Number of connections to handle before starting a new process.
24346 Typically the only useful values are 0 (unlimited) or 1. 1 is more
24347 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
24348 Defaults to @samp{1}.
24352 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
24353 Maximum number of processes that can exist for this service. If set to
24354 0, @code{default-process-limit} is used instead.
24356 Defaults to @samp{0}.
24360 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
24361 Number of processes to always keep waiting for more connections.
24362 Defaults to @samp{0}.
24365 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
24366 If you set @samp{service-count 0}, you probably need to grow
24368 Defaults to @samp{256000000}.
24373 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
24374 Dict configuration, as created by the @code{dict-configuration}
24377 Available @code{dict-configuration} fields are:
24379 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
24380 A list of key-value pairs that this dict should hold.
24381 Defaults to @samp{()}.
24386 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
24387 A list of passdb configurations, each one created by the
24388 @code{passdb-configuration} constructor.
24390 Available @code{passdb-configuration} fields are:
24392 @deftypevr {@code{passdb-configuration} parameter} string driver
24393 The driver that the passdb should use. Valid values include
24394 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
24396 Defaults to @samp{"pam"}.
24399 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
24400 Space separated list of arguments to the passdb driver.
24401 Defaults to @samp{""}.
24406 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
24407 List of userdb configurations, each one created by the
24408 @code{userdb-configuration} constructor.
24410 Available @code{userdb-configuration} fields are:
24412 @deftypevr {@code{userdb-configuration} parameter} string driver
24413 The driver that the userdb should use. Valid values include
24414 @samp{passwd} and @samp{static}.
24415 Defaults to @samp{"passwd"}.
24418 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
24419 Space separated list of arguments to the userdb driver.
24420 Defaults to @samp{""}.
24423 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
24424 Override fields from passwd.
24425 Defaults to @samp{()}.
24430 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
24431 Plug-in configuration, created by the @code{plugin-configuration}
24435 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
24436 List of namespaces. Each item in the list is created by the
24437 @code{namespace-configuration} constructor.
24439 Available @code{namespace-configuration} fields are:
24441 @deftypevr {@code{namespace-configuration} parameter} string name
24442 Name for this namespace.
24445 @deftypevr {@code{namespace-configuration} parameter} string type
24446 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
24447 Defaults to @samp{"private"}.
24450 @deftypevr {@code{namespace-configuration} parameter} string separator
24451 Hierarchy separator to use. You should use the same separator for
24452 all namespaces or some clients get confused. @samp{/} is usually a good
24453 one. The default however depends on the underlying mail storage
24455 Defaults to @samp{""}.
24458 @deftypevr {@code{namespace-configuration} parameter} string prefix
24459 Prefix required to access this namespace. This needs to be
24460 different for all namespaces. For example @samp{Public/}.
24461 Defaults to @samp{""}.
24464 @deftypevr {@code{namespace-configuration} parameter} string location
24465 Physical location of the mailbox. This is in the same format as
24466 mail_location, which is also the default for it.
24467 Defaults to @samp{""}.
24470 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
24471 There can be only one INBOX, and this setting defines which
24473 Defaults to @samp{#f}.
24476 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
24477 If namespace is hidden, it's not advertised to clients via NAMESPACE
24478 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
24479 useful when converting from another server with different namespaces
24480 which you want to deprecate but still keep working. For example you can
24481 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
24483 Defaults to @samp{#f}.
24486 @deftypevr {@code{namespace-configuration} parameter} boolean list?
24487 Show the mailboxes under this namespace with the LIST command. This
24488 makes the namespace visible for clients that do not support the NAMESPACE
24489 extension. The special @code{children} value lists child mailboxes, but
24490 hides the namespace prefix.
24491 Defaults to @samp{#t}.
24494 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
24495 Namespace handles its own subscriptions. If set to @code{#f}, the
24496 parent namespace handles them. The empty prefix should always have this
24498 Defaults to @samp{#t}.
24501 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
24502 List of predefined mailboxes in this namespace.
24503 Defaults to @samp{()}.
24505 Available @code{mailbox-configuration} fields are:
24507 @deftypevr {@code{mailbox-configuration} parameter} string name
24508 Name for this mailbox.
24511 @deftypevr {@code{mailbox-configuration} parameter} string auto
24512 @samp{create} will automatically create this mailbox.
24513 @samp{subscribe} will both create and subscribe to the mailbox.
24514 Defaults to @samp{"no"}.
24517 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
24518 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
24519 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
24520 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
24521 Defaults to @samp{()}.
24528 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
24529 Base directory where to store runtime data.
24530 Defaults to @samp{"/var/run/dovecot/"}.
24533 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
24534 Greeting message for clients.
24535 Defaults to @samp{"Dovecot ready."}.
24538 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
24539 List of trusted network ranges. Connections from these IPs are
24540 allowed to override their IP addresses and ports (for logging and for
24541 authentication checks). @samp{disable-plaintext-auth} is also ignored
24542 for these networks. Typically you would specify your IMAP proxy servers
24544 Defaults to @samp{()}.
24547 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
24548 List of login access check sockets (e.g.@: tcpwrap).
24549 Defaults to @samp{()}.
24552 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
24553 Show more verbose process titles (in ps). Currently shows user name
24554 and IP address. Useful for seeing who is actually using the IMAP
24555 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
24557 Defaults to @samp{#f}.
24560 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
24561 Should all processes be killed when Dovecot master process shuts down.
24562 Setting this to @code{#f} means that Dovecot can be upgraded without
24563 forcing existing client connections to close (although that could also
24564 be a problem if the upgrade is e.g.@: due to a security fix).
24565 Defaults to @samp{#t}.
24568 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
24569 If non-zero, run mail commands via this many connections to doveadm
24570 server, instead of running them directly in the same process.
24571 Defaults to @samp{0}.
24574 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
24575 UNIX socket or host:port used for connecting to doveadm server.
24576 Defaults to @samp{"doveadm-server"}.
24579 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
24580 List of environment variables that are preserved on Dovecot startup
24581 and passed down to all of its child processes. You can also give
24582 key=value pairs to always set specific settings.
24585 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
24586 Disable LOGIN command and all other plaintext authentications unless
24587 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
24588 matches the local IP (i.e.@: you're connecting from the same computer),
24589 the connection is considered secure and plaintext authentication is
24590 allowed. See also ssl=required setting.
24591 Defaults to @samp{#t}.
24594 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
24595 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
24596 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
24597 for caching to be used.
24598 Defaults to @samp{0}.
24601 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
24602 Time to live for cached data. After TTL expires the cached record
24603 is no longer used, *except* if the main database lookup returns internal
24604 failure. We also try to handle password changes automatically: If
24605 user's previous authentication was successful, but this one wasn't, the
24606 cache isn't used. For now this works only with plaintext
24608 Defaults to @samp{"1 hour"}.
24611 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
24612 TTL for negative hits (user not found, password mismatch).
24613 0 disables caching them completely.
24614 Defaults to @samp{"1 hour"}.
24617 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
24618 List of realms for SASL authentication mechanisms that need them.
24619 You can leave it empty if you don't want to support multiple realms.
24620 Many clients simply use the first one listed here, so keep the default
24622 Defaults to @samp{()}.
24625 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
24626 Default realm/domain to use if none was specified. This is used for
24627 both SASL realms and appending @@domain to username in plaintext
24629 Defaults to @samp{""}.
24632 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
24633 List of allowed characters in username. If the user-given username
24634 contains a character not listed in here, the login automatically fails.
24635 This is just an extra check to make sure user can't exploit any
24636 potential quote escaping vulnerabilities with SQL/LDAP databases. If
24637 you want to allow all characters, set this value to empty.
24638 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
24641 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
24642 Username character translations before it's looked up from
24643 databases. The value contains series of from -> to characters. For
24644 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
24645 translated to @samp{@@}.
24646 Defaults to @samp{""}.
24649 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
24650 Username formatting before it's looked up from databases. You can
24651 use the standard variables here, e.g.@: %Lu would lowercase the username,
24652 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
24653 change the @samp{@@} into @samp{-AT-}. This translation is done after
24654 @samp{auth-username-translation} changes.
24655 Defaults to @samp{"%Lu"}.
24658 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
24659 If you want to allow master users to log in by specifying the master
24660 username within the normal username string (i.e.@: not using SASL
24661 mechanism's support for it), you can specify the separator character
24662 here. The format is then <username><separator><master username>.
24663 UW-IMAP uses @samp{*} as the separator, so that could be a good
24665 Defaults to @samp{""}.
24668 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
24669 Username to use for users logging in with ANONYMOUS SASL
24671 Defaults to @samp{"anonymous"}.
24674 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
24675 Maximum number of dovecot-auth worker processes. They're used to
24676 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
24677 They're automatically created and destroyed as needed.
24678 Defaults to @samp{30}.
24681 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
24682 Host name to use in GSSAPI principal names. The default is to use
24683 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
24684 allow all keytab entries.
24685 Defaults to @samp{""}.
24688 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
24689 Kerberos keytab to use for the GSSAPI mechanism. Will use the
24690 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
24691 need to change the auth service to run as root to be able to read this
24693 Defaults to @samp{""}.
24696 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
24697 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
24698 and @samp{ntlm-auth} helper.
24699 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
24700 Defaults to @samp{#f}.
24703 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
24704 Path for Samba's @samp{ntlm-auth} helper binary.
24705 Defaults to @samp{"/usr/bin/ntlm_auth"}.
24708 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
24709 Time to delay before replying to failed authentications.
24710 Defaults to @samp{"2 secs"}.
24713 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
24714 Require a valid SSL client certificate or the authentication
24716 Defaults to @samp{#f}.
24719 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
24720 Take the username from client's SSL certificate, using
24721 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
24723 Defaults to @samp{#f}.
24726 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
24727 List of wanted authentication mechanisms. Supported mechanisms are:
24728 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
24729 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
24730 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
24731 @samp{disable-plaintext-auth} setting.
24734 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
24735 List of IPs or hostnames to all director servers, including ourself.
24736 Ports can be specified as ip:port. The default port is the same as what
24737 director service's @samp{inet-listener} is using.
24738 Defaults to @samp{()}.
24741 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
24742 List of IPs or hostnames to all backend mail servers. Ranges are
24743 allowed too, like 10.0.0.10-10.0.0.30.
24744 Defaults to @samp{()}.
24747 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
24748 How long to redirect users to a specific server after it no longer
24749 has any connections.
24750 Defaults to @samp{"15 min"}.
24753 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
24754 How the username is translated before being hashed. Useful values
24755 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
24756 are shared within domain.
24757 Defaults to @samp{"%Lu"}.
24760 @deftypevr {@code{dovecot-configuration} parameter} string log-path
24761 Log file to use for error messages. @samp{syslog} logs to syslog,
24762 @samp{/dev/stderr} logs to stderr.
24763 Defaults to @samp{"syslog"}.
24766 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
24767 Log file to use for informational messages. Defaults to
24769 Defaults to @samp{""}.
24772 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
24773 Log file to use for debug messages. Defaults to
24774 @samp{info-log-path}.
24775 Defaults to @samp{""}.
24778 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
24779 Syslog facility to use if you're logging to syslog. Usually if you
24780 don't want to use @samp{mail}, you'll use local0..local7. Also other
24781 standard facilities are supported.
24782 Defaults to @samp{"mail"}.
24785 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
24786 Log unsuccessful authentication attempts and the reasons why they
24788 Defaults to @samp{#f}.
24791 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
24792 In case of password mismatches, log the attempted password. Valid
24793 values are no, plain and sha1. sha1 can be useful for detecting brute
24794 force password attempts vs. user simply trying the same password over
24795 and over again. You can also truncate the value to n chars by appending
24796 ":n" (e.g.@: sha1:6).
24797 Defaults to @samp{"no"}.
24800 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
24801 Even more verbose logging for debugging purposes. Shows for example
24803 Defaults to @samp{#f}.
24806 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
24807 In case of password mismatches, log the passwords and used scheme so
24808 the problem can be debugged. Enabling this also enables
24810 Defaults to @samp{#f}.
24813 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
24814 Enable mail process debugging. This can help you figure out why
24815 Dovecot isn't finding your mails.
24816 Defaults to @samp{#f}.
24819 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
24820 Show protocol level SSL errors.
24821 Defaults to @samp{#f}.
24824 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
24825 Prefix for each line written to log file. % codes are in
24826 strftime(3) format.
24827 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
24830 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
24831 List of elements we want to log. The elements which have a
24832 non-empty variable value are joined together to form a comma-separated
24836 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
24837 Login log format. %s contains @samp{login-log-format-elements}
24838 string, %$ contains the data we want to log.
24839 Defaults to @samp{"%$: %s"}.
24842 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
24843 Log prefix for mail processes. See doc/wiki/Variables.txt for list
24844 of possible variables you can use.
24845 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
24848 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
24849 Format to use for logging mail deliveries. You can use variables:
24852 Delivery status message (e.g.@: @samp{saved to INBOX})
24864 Defaults to @samp{"msgid=%m: %$"}.
24867 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
24868 Location for users' mailboxes. The default is empty, which means
24869 that Dovecot tries to find the mailboxes automatically. This won't work
24870 if the user doesn't yet have any mail, so you should explicitly tell
24871 Dovecot the full location.
24873 If you're using mbox, giving a path to the INBOX
24874 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
24875 where the other mailboxes are kept. This is called the @emph{root mail
24876 directory}, and it must be the first path given in the
24877 @samp{mail-location} setting.
24879 There are a few special variables you can use, e.g.:
24885 user part in user@@domain, same as %u if there's no domain
24887 domain part in user@@domain, empty if there's no domain
24892 See doc/wiki/Variables.txt for full list. Some examples:
24894 @item maildir:~/Maildir
24895 @item mbox:~/mail:INBOX=/var/mail/%u
24896 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
24898 Defaults to @samp{""}.
24901 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
24902 System user and group used to access mails. If you use multiple,
24903 userdb can override these by returning uid or gid fields. You can use
24904 either numbers or names. <doc/wiki/UserIds.txt>.
24905 Defaults to @samp{""}.
24908 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
24910 Defaults to @samp{""}.
24913 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
24914 Group to enable temporarily for privileged operations. Currently
24915 this is used only with INBOX when either its initial creation or
24916 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
24918 Defaults to @samp{""}.
24921 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
24922 Grant access to these supplementary groups for mail processes.
24923 Typically these are used to set up access to shared mailboxes. Note
24924 that it may be dangerous to set these if users can create symlinks
24925 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
24926 could allow a user to delete others' mailboxes, or @code{ln -s
24927 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
24931 @deftypevr {@code{dovecot-configuration} parameter} string mail-attribute-dict
24932 The location of a dictionary used to store @code{IMAP METADATA}
24933 as defined by @uref{https://tools.ietf.org/html/rfc5464, RFC@tie{}5464}.
24935 The IMAP METADATA commands are available only if the ``imap''
24936 protocol configuration's @code{imap-metadata?} field is @samp{#t}.
24938 Defaults to @samp{""}.
24942 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
24943 Allow full file system access to clients. There's no access checks
24944 other than what the operating system does for the active UID/GID@. It
24945 works with both maildir and mboxes, allowing you to prefix mailboxes
24946 names with e.g.@: @file{/path/} or @file{~user/}.
24947 Defaults to @samp{#f}.
24950 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
24951 Don't use @code{mmap()} at all. This is required if you store indexes to
24952 shared file systems (NFS or clustered file system).
24953 Defaults to @samp{#f}.
24956 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
24957 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
24958 supports @samp{O_EXCL} since version 3, so this should be safe to use
24959 nowadays by default.
24960 Defaults to @samp{#t}.
24963 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
24964 When to use fsync() or fdatasync() calls:
24967 Whenever necessary to avoid losing important data
24969 Useful with e.g.@: NFS when @code{write()}s are delayed
24971 Never use it (best performance, but crashes can lose data).
24973 Defaults to @samp{"optimized"}.
24976 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
24977 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
24978 NFS caches whenever needed. If you're using only a single mail server
24980 Defaults to @samp{#f}.
24983 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
24984 Mail index files also exist in NFS@. Setting this to yes requires
24985 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
24986 Defaults to @samp{#f}.
24989 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
24990 Locking method for index files. Alternatives are fcntl, flock and
24991 dotlock. Dotlocking uses some tricks which may create more disk I/O
24992 than other locking methods. NFS users: flock doesn't work, remember to
24993 change @samp{mmap-disable}.
24994 Defaults to @samp{"fcntl"}.
24997 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
24998 Directory in which LDA/LMTP temporarily stores incoming mails >128
25000 Defaults to @samp{"/tmp"}.
25003 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
25004 Valid UID range for users. This is mostly to make sure that users can't
25005 log in as daemons or other system users. Note that denying root logins is
25006 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
25008 Defaults to @samp{500}.
25011 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
25013 Defaults to @samp{0}.
25016 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
25017 Valid GID range for users. Users having non-valid GID as primary group ID
25018 aren't allowed to log in. If user belongs to supplementary groups with
25019 non-valid GIDs, those groups are not set.
25020 Defaults to @samp{1}.
25023 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
25025 Defaults to @samp{0}.
25028 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
25029 Maximum allowed length for mail keyword name. It's only forced when
25030 trying to create new keywords.
25031 Defaults to @samp{50}.
25034 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
25035 List of directories under which chrooting is allowed for mail
25036 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
25037 too). This setting doesn't affect @samp{login-chroot}
25038 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
25039 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
25040 which local users can modify, that may lead to root exploit. Usually
25041 this should be done only if you don't allow shell access for users.
25042 <doc/wiki/Chrooting.txt>.
25043 Defaults to @samp{()}.
25046 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
25047 Default chroot directory for mail processes. This can be overridden
25048 for specific users in user database by giving @samp{/./} in user's home
25049 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
25050 there is no real need to do chrooting, Dovecot doesn't allow users to
25051 access files outside their mail directory anyway. If your home
25052 directories are prefixed with the chroot directory, append @samp{/.} to
25053 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
25054 Defaults to @samp{""}.
25057 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
25058 UNIX socket path to master authentication server to find users.
25059 This is used by imap (for shared users) and lda.
25060 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
25063 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
25064 Directory where to look up mail plugins.
25065 Defaults to @samp{"/usr/lib/dovecot"}.
25068 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
25069 List of plugins to load for all services. Plugins specific to IMAP,
25070 LDA, etc.@: are added to this list in their own .conf files.
25071 Defaults to @samp{()}.
25074 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
25075 The minimum number of mails in a mailbox before updates are done to
25076 cache file. This allows optimizing Dovecot's behavior to do less disk
25077 writes at the cost of more disk reads.
25078 Defaults to @samp{0}.
25081 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
25082 When IDLE command is running, mailbox is checked once in a while to
25083 see if there are any new mails or other changes. This setting defines
25084 the minimum time to wait between those checks. Dovecot can also use
25085 dnotify, inotify and kqueue to find out immediately when changes
25087 Defaults to @samp{"30 secs"}.
25090 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
25091 Save mails with CR+LF instead of plain LF@. This makes sending those
25092 mails take less CPU, especially with sendfile() syscall with Linux and
25093 FreeBSD@. But it also creates a bit more disk I/O which may just make it
25094 slower. Also note that if other software reads the mboxes/maildirs,
25095 they may handle the extra CRs wrong and cause problems.
25096 Defaults to @samp{#f}.
25099 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
25100 By default LIST command returns all entries in maildir beginning
25101 with a dot. Enabling this option makes Dovecot return only entries
25102 which are directories. This is done by stat()ing each entry, so it
25103 causes more disk I/O.
25104 (For systems setting struct @samp{dirent->d_type} this check is free
25105 and it's done always regardless of this setting).
25106 Defaults to @samp{#f}.
25109 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
25110 When copying a message, do it with hard links whenever possible.
25111 This makes the performance much better, and it's unlikely to have any
25113 Defaults to @samp{#t}.
25116 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
25117 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
25118 directory only when its mtime changes unexpectedly or when we can't find
25119 the mail otherwise.
25120 Defaults to @samp{#f}.
25123 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
25124 Which locking methods to use for locking mbox. There are four
25129 Create <mailbox>.lock file. This is the oldest and most NFS-safe
25130 solution. If you want to use /var/mail/ like directory, the users will
25131 need write access to that directory.
25133 Same as dotlock, but if it fails because of permissions or because there
25134 isn't enough disk space, just skip it.
25136 Use this if possible. Works with NFS too if lockd is used.
25138 May not exist in all systems. Doesn't work with NFS.
25140 May not exist in all systems. Doesn't work with NFS.
25143 You can use multiple locking methods; if you do the order they're declared
25144 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
25145 locking methods as well. Some operating systems don't allow using some of
25146 them simultaneously.
25149 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
25153 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
25154 Maximum time to wait for lock (all of them) before aborting.
25155 Defaults to @samp{"5 mins"}.
25158 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
25159 If dotlock exists but the mailbox isn't modified in any way,
25160 override the lock file after this much time.
25161 Defaults to @samp{"2 mins"}.
25164 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
25165 When mbox changes unexpectedly we have to fully read it to find out
25166 what changed. If the mbox is large this can take a long time. Since
25167 the change is usually just a newly appended mail, it'd be faster to
25168 simply read the new mails. If this setting is enabled, Dovecot does
25169 this but still safely fallbacks to re-reading the whole mbox file
25170 whenever something in mbox isn't how it's expected to be. The only real
25171 downside to this setting is that if some other MUA changes message
25172 flags, Dovecot doesn't notice it immediately. Note that a full sync is
25173 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
25174 Defaults to @samp{#t}.
25177 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
25178 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
25179 EXAMINE, EXPUNGE or CHECK commands. If this is set,
25180 @samp{mbox-dirty-syncs} is ignored.
25181 Defaults to @samp{#f}.
25184 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
25185 Delay writing mbox headers until doing a full write sync (EXPUNGE
25186 and CHECK commands and when closing the mailbox). This is especially
25187 useful for POP3 where clients often delete all mails. The downside is
25188 that our changes aren't immediately visible to other MUAs.
25189 Defaults to @samp{#t}.
25192 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
25193 If mbox size is smaller than this (e.g.@: 100k), don't write index
25194 files. If an index file already exists it's still read, just not
25196 Defaults to @samp{0}.
25199 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
25200 Maximum dbox file size until it's rotated.
25201 Defaults to @samp{10000000}.
25204 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
25205 Maximum dbox file age until it's rotated. Typically in days. Day
25206 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
25208 Defaults to @samp{"1d"}.
25211 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
25212 When creating new mdbox files, immediately preallocate their size to
25213 @samp{mdbox-rotate-size}. This setting currently works only in Linux
25214 with some file systems (ext4, xfs).
25215 Defaults to @samp{#f}.
25218 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
25219 sdbox and mdbox support saving mail attachments to external files,
25220 which also allows single instance storage for them. Other backends
25221 don't support this for now.
25223 WARNING: This feature hasn't been tested much yet. Use at your own risk.
25225 Directory root where to store mail attachments. Disabled, if empty.
25226 Defaults to @samp{""}.
25229 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
25230 Attachments smaller than this aren't saved externally. It's also
25231 possible to write a plugin to disable saving specific attachments
25233 Defaults to @samp{128000}.
25236 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
25237 File system backend to use for saving attachments:
25240 No SiS done by Dovecot (but this might help FS's own deduplication)
25242 SiS with immediate byte-by-byte comparison during saving
25243 @item sis-queue posix
25244 SiS with delayed comparison and deduplication.
25246 Defaults to @samp{"sis posix"}.
25249 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
25250 Hash format to use in attachment filenames. You can add any text and
25251 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
25252 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
25253 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
25254 Defaults to @samp{"%@{sha1@}"}.
25257 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
25259 Defaults to @samp{100}.
25262 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
25264 Defaults to @samp{1000}.
25267 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
25268 Default VSZ (virtual memory size) limit for service processes.
25269 This is mainly intended to catch and kill processes that leak memory
25270 before they eat up everything.
25271 Defaults to @samp{256000000}.
25274 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
25275 Login user is internally used by login processes. This is the most
25276 untrusted user in Dovecot system. It shouldn't have access to anything
25278 Defaults to @samp{"dovenull"}.
25281 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
25282 Internal user is used by unprivileged processes. It should be
25283 separate from login user, so that login processes can't disturb other
25285 Defaults to @samp{"dovecot"}.
25288 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
25289 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
25290 Defaults to @samp{"required"}.
25293 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
25294 PEM encoded X.509 SSL/TLS certificate (public key).
25295 Defaults to @samp{"</etc/dovecot/default.pem"}.
25298 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
25299 PEM encoded SSL/TLS private key. The key is opened before
25300 dropping root privileges, so keep the key file unreadable by anyone but
25302 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
25305 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
25306 If key file is password protected, give the password here.
25307 Alternatively give it when starting dovecot with -p parameter. Since
25308 this file is often world-readable, you may want to place this setting
25309 instead to a different.
25310 Defaults to @samp{""}.
25313 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
25314 PEM encoded trusted certificate authority. Set this only if you
25315 intend to use @samp{ssl-verify-client-cert? #t}. The file should
25316 contain the CA certificate(s) followed by the matching
25317 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
25318 Defaults to @samp{""}.
25321 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
25322 Require that CRL check succeeds for client certificates.
25323 Defaults to @samp{#t}.
25326 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
25327 Request client to send a certificate. If you also want to require
25328 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
25329 Defaults to @samp{#f}.
25332 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
25333 Which field from certificate to use for username. commonName and
25334 x500UniqueIdentifier are the usual choices. You'll also need to set
25335 @samp{auth-ssl-username-from-cert? #t}.
25336 Defaults to @samp{"commonName"}.
25339 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
25340 Minimum SSL protocol version to accept.
25341 Defaults to @samp{"TLSv1"}.
25344 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
25345 SSL ciphers to use.
25346 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
25349 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
25350 SSL crypto device to use, for valid values run "openssl engine".
25351 Defaults to @samp{""}.
25354 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
25355 Address to use when sending rejection mails.
25356 %d expands to recipient domain.
25357 Defaults to @samp{"postmaster@@%d"}.
25360 @deftypevr {@code{dovecot-configuration} parameter} string hostname
25361 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
25362 and in LMTP replies. Default is the system's real hostname@@domain.
25363 Defaults to @samp{""}.
25366 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
25367 If user is over quota, return with temporary failure instead of
25369 Defaults to @samp{#f}.
25372 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
25373 Binary to use for sending mails.
25374 Defaults to @samp{"/usr/sbin/sendmail"}.
25377 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
25378 If non-empty, send mails via this SMTP host[:port] instead of
25380 Defaults to @samp{""}.
25383 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
25384 Subject: header to use for rejection mails. You can use the same
25385 variables as for @samp{rejection-reason} below.
25386 Defaults to @samp{"Rejected: %s"}.
25389 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
25390 Human readable error message for rejection mails. You can use
25403 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
25406 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
25407 Delimiter character between local-part and detail in email
25409 Defaults to @samp{"+"}.
25412 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
25413 Header where the original recipient address (SMTP's RCPT TO:
25414 address) is taken from if not available elsewhere. With dovecot-lda -a
25415 parameter overrides this. A commonly used header for this is
25417 Defaults to @samp{""}.
25420 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
25421 Should saving a mail to a nonexistent mailbox automatically create
25423 Defaults to @samp{#f}.
25426 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
25427 Should automatically created mailboxes be also automatically
25429 Defaults to @samp{#f}.
25432 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
25433 Maximum IMAP command line length. Some clients generate very long
25434 command lines with huge mailboxes, so you may need to raise this if you
25435 get "Too long argument" or "IMAP command line too large" errors
25437 Defaults to @samp{64000}.
25440 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
25441 IMAP logout format string:
25444 total number of bytes read from client
25446 total number of bytes sent to client.
25448 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
25449 Defaults to @samp{"in=%i out=%o deleted=%@{deleted@} expunged=%@{expunged@} trashed=%@{trashed@} hdr_count=%@{fetch_hdr_count@} hdr_bytes=%@{fetch_hdr_bytes@} body_count=%@{fetch_body_count@} body_bytes=%@{fetch_body_bytes@}"}.
25452 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
25453 Override the IMAP CAPABILITY response. If the value begins with '+',
25454 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
25455 Defaults to @samp{""}.
25458 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
25459 How long to wait between "OK Still here" notifications when client
25461 Defaults to @samp{"2 mins"}.
25464 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
25465 ID field names and values to send to clients. Using * as the value
25466 makes Dovecot use the default value. The following fields have default
25467 values currently: name, version, os, os-version, support-url,
25469 Defaults to @samp{""}.
25472 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
25473 ID fields sent by client to log. * means everything.
25474 Defaults to @samp{""}.
25477 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
25478 Workarounds for various client bugs:
25481 @item delay-newmail
25482 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
25483 CHECK commands. Some clients ignore them otherwise, for example OSX
25484 Mail (<v2.1). Outlook Express breaks more badly though, without this it
25485 may show user "Message no longer in server" errors. Note that OE6
25486 still breaks even with this workaround if synchronization is set to
25489 @item tb-extra-mailbox-sep
25490 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
25491 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
25492 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
25494 @item tb-lsub-flags
25495 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
25496 This makes Thunderbird realize they aren't selectable and show them
25497 greyed out, instead of only later giving "not selectable" popup error.
25499 Defaults to @samp{()}.
25502 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
25503 Host allowed in URLAUTH URLs sent by client. "*" allows all.
25504 Defaults to @samp{""}.
25508 Whew! Lots of configuration options. The nice thing about it though is
25509 that Guix has a complete interface to Dovecot's configuration
25510 language. This allows not only a nice way to declare configurations,
25511 but also offers reflective capabilities as well: users can write code to
25512 inspect and transform configurations from within Scheme.
25514 However, it could be that you just want to get a @code{dovecot.conf} up
25515 and running. In that case, you can pass an
25516 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
25517 @code{dovecot-service}. As its name indicates, an opaque configuration
25518 does not have easy reflective capabilities.
25520 Available @code{opaque-dovecot-configuration} fields are:
25522 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
25523 The dovecot package.
25526 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
25527 The contents of the @code{dovecot.conf}, as a string.
25530 For example, if your @code{dovecot.conf} is just the empty string, you
25531 could instantiate a dovecot service like this:
25534 (dovecot-service #:config
25535 (opaque-dovecot-configuration
25539 @subsubheading OpenSMTPD Service
25541 @deffn {Scheme Variable} opensmtpd-service-type
25542 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
25543 service, whose value should be an @code{opensmtpd-configuration} object
25544 as in this example:
25547 (service opensmtpd-service-type
25548 (opensmtpd-configuration
25549 (config-file (local-file "./my-smtpd.conf"))))
25553 @deftp {Data Type} opensmtpd-configuration
25554 Data type representing the configuration of opensmtpd.
25557 @item @code{package} (default: @var{opensmtpd})
25558 Package object of the OpenSMTPD SMTP server.
25560 @item @code{config-file} (default: @code{%default-opensmtpd-config-file})
25561 File-like object of the OpenSMTPD configuration file to use. By default
25562 it listens on the loopback network interface, and allows for mail from
25563 users and daemons on the local machine, as well as permitting email to
25564 remote servers. Run @command{man smtpd.conf} for more information.
25566 @item @code{setgid-commands?} (default: @code{#t})
25567 Make the following commands setgid to @code{smtpq} so they can be
25568 executed: @command{smtpctl}, @command{sendmail}, @command{send-mail},
25569 @command{makemap}, @command{mailq}, and @command{newaliases}.
25570 @xref{Setuid Programs}, for more information on setgid programs.
25574 @subsubheading Exim Service
25576 @cindex mail transfer agent (MTA)
25577 @cindex MTA (mail transfer agent)
25580 @deffn {Scheme Variable} exim-service-type
25581 This is the type of the @uref{https://exim.org, Exim} mail transfer
25582 agent (MTA), whose value should be an @code{exim-configuration} object
25583 as in this example:
25586 (service exim-service-type
25587 (exim-configuration
25588 (config-file (local-file "./my-exim.conf"))))
25592 In order to use an @code{exim-service-type} service you must also have a
25593 @code{mail-aliases-service-type} service present in your
25594 @code{operating-system} (even if it has no aliases).
25596 @deftp {Data Type} exim-configuration
25597 Data type representing the configuration of exim.
25600 @item @code{package} (default: @var{exim})
25601 Package object of the Exim server.
25603 @item @code{config-file} (default: @code{#f})
25604 File-like object of the Exim configuration file to use. If its value is
25605 @code{#f} then use the default configuration file from the package
25606 provided in @code{package}. The resulting configuration file is loaded
25607 after setting the @code{exim_user} and @code{exim_group} configuration
25613 @subsubheading Getmail service
25618 @deffn {Scheme Variable} getmail-service-type
25619 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
25620 mail retriever, whose value should be an @code{getmail-configuration}.
25623 Available @code{getmail-configuration} fields are:
25625 @deftypevr {@code{getmail-configuration} parameter} symbol name
25626 A symbol to identify the getmail service.
25628 Defaults to @samp{"unset"}.
25632 @deftypevr {@code{getmail-configuration} parameter} package package
25633 The getmail package to use.
25637 @deftypevr {@code{getmail-configuration} parameter} string user
25638 The user to run getmail as.
25640 Defaults to @samp{"getmail"}.
25644 @deftypevr {@code{getmail-configuration} parameter} string group
25645 The group to run getmail as.
25647 Defaults to @samp{"getmail"}.
25651 @deftypevr {@code{getmail-configuration} parameter} string directory
25652 The getmail directory to use.
25654 Defaults to @samp{"/var/lib/getmail/default"}.
25658 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
25659 The getmail configuration file to use.
25661 Available @code{getmail-configuration-file} fields are:
25663 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
25664 What mail account to retrieve mail from, and how to access that account.
25666 Available @code{getmail-retriever-configuration} fields are:
25668 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
25669 The type of mail retriever to use. Valid values include @samp{passwd}
25672 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
25676 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
25677 Username to login to the mail server with.
25679 Defaults to @samp{unset}.
25683 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
25684 Username to login to the mail server with.
25686 Defaults to @samp{unset}.
25690 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
25691 Port number to connect to.
25693 Defaults to @samp{#f}.
25697 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
25698 Override fields from passwd.
25700 Defaults to @samp{""}.
25704 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
25705 Override fields from passwd.
25707 Defaults to @samp{()}.
25711 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
25712 PEM-formatted key file to use for the TLS negotiation.
25714 Defaults to @samp{""}.
25718 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
25719 PEM-formatted certificate file to use for the TLS negotiation.
25721 Defaults to @samp{""}.
25725 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
25726 CA certificates to use.
25728 Defaults to @samp{""}.
25732 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
25733 Extra retriever parameters.
25735 Defaults to @samp{()}.
25741 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
25742 What to do with retrieved messages.
25744 Available @code{getmail-destination-configuration} fields are:
25746 @deftypevr {@code{getmail-destination-configuration} parameter} string type
25747 The type of mail destination. Valid values include @samp{Maildir},
25748 @samp{Mboxrd} and @samp{MDA_external}.
25750 Defaults to @samp{unset}.
25754 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
25755 The path option for the mail destination. The behaviour depends on the
25758 Defaults to @samp{""}.
25762 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
25763 Extra destination parameters
25765 Defaults to @samp{()}.
25771 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
25774 Available @code{getmail-options-configuration} fields are:
25776 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
25777 If set to @samp{0}, getmail will only print warnings and errors. A
25778 value of @samp{1} means that messages will be printed about retrieving
25779 and deleting messages. If set to @samp{2}, getmail will print messages
25780 about each of its actions.
25782 Defaults to @samp{1}.
25786 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
25787 If true, getmail will retrieve all available messages. Otherwise it
25788 will only retrieve messages it hasn't seen previously.
25790 Defaults to @samp{#t}.
25794 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
25795 If set to true, messages will be deleted from the server after
25796 retrieving and successfully delivering them. Otherwise, messages will
25797 be left on the server.
25799 Defaults to @samp{#f}.
25803 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
25804 Getmail will delete messages this number of days after seeing them, if
25805 they have been delivered. This means messages will be left on the
25806 server this number of days after delivering them. A value of @samp{0}
25807 disabled this feature.
25809 Defaults to @samp{0}.
25813 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
25814 Delete messages larger than this of bytes after retrieving them, even if
25815 the delete and delete-after options are disabled. A value of @samp{0}
25816 disables this feature.
25818 Defaults to @samp{0}.
25822 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
25823 Retrieve messages totalling up to this number of bytes before closing
25824 the session with the server. A value of @samp{0} disables this feature.
25826 Defaults to @samp{0}.
25830 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
25831 Don't retrieve messages larger than this number of bytes. A value of
25832 @samp{0} disables this feature.
25834 Defaults to @samp{0}.
25838 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
25839 If true, getmail will add a Delivered-To header to messages.
25841 Defaults to @samp{#t}.
25845 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
25846 If set, getmail adds a Received header to the messages.
25848 Defaults to @samp{#t}.
25852 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
25853 Getmail will record a log of its actions to the named file. A value of
25854 @samp{""} disables this feature.
25856 Defaults to @samp{""}.
25860 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
25861 If true, getmail will record a log of its actions using the system
25864 Defaults to @samp{#f}.
25868 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
25869 If true, getmail will log information about messages not retrieved and
25870 the reason for not retrieving them, as well as starting and ending
25873 Defaults to @samp{#f}.
25877 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
25878 Extra options to include.
25880 Defaults to @samp{()}.
25888 @deftypevr {@code{getmail-configuration} parameter} list idle
25889 A list of mailboxes that getmail should wait on the server for new mail
25890 notifications. This depends on the server supporting the IDLE
25893 Defaults to @samp{()}.
25897 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
25898 Environment variables to set for getmail.
25900 Defaults to @samp{()}.
25904 @subsubheading Mail Aliases Service
25906 @cindex email aliases
25907 @cindex aliases, for email addresses
25909 @deffn {Scheme Variable} mail-aliases-service-type
25910 This is the type of the service which provides @code{/etc/aliases},
25911 specifying how to deliver mail to users on this system.
25914 (service mail-aliases-service-type
25915 '(("postmaster" "bob")
25916 ("bob" "bob@@example.com" "bob@@example2.com")))
25920 The configuration for a @code{mail-aliases-service-type} service is an
25921 association list denoting how to deliver mail that comes to this
25922 system. Each entry is of the form @code{(alias addresses ...)}, with
25923 @code{alias} specifying the local alias and @code{addresses} specifying
25924 where to deliver this user's mail.
25926 The aliases aren't required to exist as users on the local system. In
25927 the above example, there doesn't need to be a @code{postmaster} entry in
25928 the @code{operating-system}'s @code{user-accounts} in order to deliver
25929 the @code{postmaster} mail to @code{bob} (which subsequently would
25930 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
25932 @subsubheading GNU Mailutils IMAP4 Daemon
25933 @cindex GNU Mailutils IMAP4 Daemon
25935 @deffn {Scheme Variable} imap4d-service-type
25936 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
25937 mailutils, GNU Mailutils Manual}), whose value should be an
25938 @code{imap4d-configuration} object as in this example:
25941 (service imap4d-service-type
25942 (imap4d-configuration
25943 (config-file (local-file "imap4d.conf"))))
25947 @deftp {Data Type} imap4d-configuration
25948 Data type representing the configuration of @command{imap4d}.
25951 @item @code{package} (default: @code{mailutils})
25952 The package that provides @command{imap4d}.
25954 @item @code{config-file} (default: @code{%default-imap4d-config-file})
25955 File-like object of the configuration file to use, by default it will listen
25956 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
25957 Mailutils Manual}, for details.
25962 @subsubheading Radicale Service
25966 @deffn {Scheme Variable} radicale-service-type
25967 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
25968 server whose value should be a @code{radicale-configuration}.
25971 @deftp {Data Type} radicale-configuration
25972 Data type representing the configuration of @command{radicale}.
25975 @item @code{package} (default: @code{radicale})
25976 The package that provides @command{radicale}.
25978 @item @code{config-file} (default: @code{%default-radicale-config-file})
25979 File-like object of the configuration file to use, by default it will listen
25980 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
25981 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
25986 @node Messaging Services
25987 @subsection Messaging Services
25992 The @code{(gnu services messaging)} module provides Guix service
25993 definitions for messaging services. Currently it provides the following
25996 @subsubheading Prosody Service
25998 @deffn {Scheme Variable} prosody-service-type
25999 This is the type for the @uref{https://prosody.im, Prosody XMPP
26000 communication server}. Its value must be a @code{prosody-configuration}
26001 record as in this example:
26004 (service prosody-service-type
26005 (prosody-configuration
26006 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
26009 (int-component-configuration
26010 (hostname "conference.example.net")
26012 (mod-muc (mod-muc-configuration)))))
26015 (virtualhost-configuration
26016 (domain "example.net"))))))
26019 See below for details about @code{prosody-configuration}.
26023 By default, Prosody does not need much configuration. Only one
26024 @code{virtualhosts} field is needed: it specifies the domain you wish
26027 You can perform various sanity checks on the generated configuration
26028 with the @code{prosodyctl check} command.
26030 Prosodyctl will also help you to import certificates from the
26031 @code{letsencrypt} directory so that the @code{prosody} user can access
26032 them. See @url{https://prosody.im/doc/letsencrypt}.
26035 prosodyctl --root cert import /etc/letsencrypt/live
26038 The available configuration parameters follow. Each parameter
26039 definition is preceded by its type; for example, @samp{string-list foo}
26040 indicates that the @code{foo} parameter should be specified as a list of
26041 strings. Types starting with @code{maybe-} denote parameters that won't
26042 show up in @code{prosody.cfg.lua} when their value is left unspecified.
26044 There is also a way to specify the configuration as a string, if you
26045 have an old @code{prosody.cfg.lua} file that you want to port over from
26046 some other system; see the end for more details.
26048 The @code{file-object} type designates either a file-like object
26049 (@pxref{G-Expressions, file-like objects}) or a file name.
26051 @c The following documentation was initially generated by
26052 @c (generate-documentation) in (gnu services messaging). Manually maintained
26053 @c documentation is better, so we shouldn't hesitate to edit below as
26054 @c needed. However if the change you want to make to this documentation
26055 @c can be done in an automated way, it's probably easier to change
26056 @c (generate-documentation) than to make it below and have to deal with
26057 @c the churn as Prosody updates.
26059 Available @code{prosody-configuration} fields are:
26061 @deftypevr {@code{prosody-configuration} parameter} package prosody
26062 The Prosody package.
26065 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
26066 Location of the Prosody data storage directory. See
26067 @url{https://prosody.im/doc/configure}.
26068 Defaults to @samp{"/var/lib/prosody"}.
26071 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
26072 Additional plugin directories. They are searched in all the specified
26073 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
26074 Defaults to @samp{()}.
26077 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
26078 Every virtual host and component needs a certificate so that clients and
26079 servers can securely verify its identity. Prosody will automatically load
26080 certificates/keys from the directory specified here.
26081 Defaults to @samp{"/etc/prosody/certs"}.
26084 @deftypevr {@code{prosody-configuration} parameter} string-list admins
26085 This is a list of accounts that are admins for the server. Note that you
26086 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
26087 @url{https://prosody.im/doc/creating_accounts}.
26088 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
26089 Defaults to @samp{()}.
26092 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
26093 Enable use of libevent for better performance under high load. See
26094 @url{https://prosody.im/doc/libevent}.
26095 Defaults to @samp{#f}.
26098 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
26099 This is the list of modules Prosody will load on startup. It looks for
26100 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
26101 Documentation on modules can be found at:
26102 @url{https://prosody.im/doc/modules}.
26103 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
26106 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
26107 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
26108 should you want to disable them then add them to this list.
26109 Defaults to @samp{()}.
26112 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
26113 Path to a text file where the shared groups are defined. If this path is
26114 empty then @samp{mod_groups} does nothing. See
26115 @url{https://prosody.im/doc/modules/mod_groups}.
26116 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
26119 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
26120 Disable account creation by default, for security. See
26121 @url{https://prosody.im/doc/creating_accounts}.
26122 Defaults to @samp{#f}.
26125 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
26126 These are the SSL/TLS-related settings. Most of them are disabled so to
26127 use Prosody's defaults. If you do not completely understand these options, do
26128 not add them to your config, it is easy to lower the security of your server
26129 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
26131 Available @code{ssl-configuration} fields are:
26133 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
26134 This determines what handshake to use.
26137 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
26138 Path to your private key file.
26141 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
26142 Path to your certificate file.
26145 @deftypevr {@code{ssl-configuration} parameter} file-object capath
26146 Path to directory containing root certificates that you wish Prosody to
26147 trust when verifying the certificates of remote servers.
26148 Defaults to @samp{"/etc/ssl/certs"}.
26151 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
26152 Path to a file containing root certificates that you wish Prosody to trust.
26153 Similar to @code{capath} but with all certificates concatenated together.
26156 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
26157 A list of verification options (these mostly map to OpenSSL's
26158 @code{set_verify()} flags).
26161 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
26162 A list of general options relating to SSL/TLS@. These map to OpenSSL's
26163 @code{set_options()}. For a full list of options available in LuaSec, see the
26167 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
26168 How long a chain of certificate authorities to check when looking for a
26169 trusted root certificate.
26172 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
26173 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
26174 clients, and in what order.
26177 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
26178 A path to a file containing parameters for Diffie-Hellman key exchange. You
26179 can create such a file with:
26180 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
26183 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
26184 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
26185 @samp{"secp384r1"}.
26188 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
26189 A list of ``extra'' verification options.
26192 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
26193 Password for encrypted private keys.
26198 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
26199 Whether to force all client-to-server connections to be encrypted or not.
26200 See @url{https://prosody.im/doc/modules/mod_tls}.
26201 Defaults to @samp{#f}.
26204 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
26205 Set of mechanisms that will never be offered. See
26206 @url{https://prosody.im/doc/modules/mod_saslauth}.
26207 Defaults to @samp{("DIGEST-MD5")}.
26210 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
26211 Whether to force all server-to-server connections to be encrypted or not.
26212 See @url{https://prosody.im/doc/modules/mod_tls}.
26213 Defaults to @samp{#f}.
26216 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
26217 Whether to require encryption and certificate authentication. This
26218 provides ideal security, but requires servers you communicate with to support
26219 encryption AND present valid, trusted certificates. See
26220 @url{https://prosody.im/doc/s2s#security}.
26221 Defaults to @samp{#f}.
26224 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
26225 Many servers don't support encryption or have invalid or self-signed
26226 certificates. You can list domains here that will not be required to
26227 authenticate using certificates. They will be authenticated using DNS@. See
26228 @url{https://prosody.im/doc/s2s#security}.
26229 Defaults to @samp{()}.
26232 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
26233 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
26234 valid certificates for some domains by specifying a list here. See
26235 @url{https://prosody.im/doc/s2s#security}.
26236 Defaults to @samp{()}.
26239 @deftypevr {@code{prosody-configuration} parameter} string authentication
26240 Select the authentication backend to use. The default provider stores
26241 passwords in plaintext and uses Prosody's configured data storage to store the
26242 authentication data. If you do not trust your server please see
26243 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
26244 about using the hashed backend. See also
26245 @url{https://prosody.im/doc/authentication}
26246 Defaults to @samp{"internal_plain"}.
26249 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
26250 Set logging options. Advanced logging configuration is not yet supported
26251 by the Prosody service. See @url{https://prosody.im/doc/logging}.
26252 Defaults to @samp{"*syslog"}.
26255 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
26256 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
26257 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
26260 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
26261 Maximum allowed size of the HTTP body (in bytes).
26264 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
26265 Some modules expose their own URL in various ways. This URL is built
26266 from the protocol, host and port used. If Prosody sits behind a proxy, the
26267 public URL will be @code{http-external-url} instead. See
26268 @url{https://prosody.im/doc/http#external_url}.
26271 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
26272 A host in Prosody is a domain on which user accounts can be created. For
26273 example if you want your users to have addresses like
26274 @samp{"john.smith@@example.com"} then you need to add a host
26275 @samp{"example.com"}. All options in this list will apply only to this host.
26278 The name @emph{virtual} host is used in configuration to avoid confusion with
26279 the actual physical host that Prosody is installed on. A single Prosody
26280 instance can serve many domains, each one defined as a VirtualHost entry in
26281 Prosody's configuration. Conversely a server that hosts a single domain would
26282 have just one VirtualHost entry.
26284 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
26287 Available @code{virtualhost-configuration} fields are:
26289 all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
26290 @deftypevr {@code{virtualhost-configuration} parameter} string domain
26291 Domain you wish Prosody to serve.
26296 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
26297 Components are extra services on a server which are available to clients,
26298 usually on a subdomain of the main server (such as
26299 @samp{"mycomponent.example.com"}). Example components might be chatroom
26300 servers, user directories, or gateways to other protocols.
26302 Internal components are implemented with Prosody-specific plugins. To add an
26303 internal component, you simply fill the hostname field, and the plugin you wish
26304 to use for the component.
26306 See @url{https://prosody.im/doc/components}.
26307 Defaults to @samp{()}.
26309 Available @code{int-component-configuration} fields are:
26311 all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
26312 @deftypevr {@code{int-component-configuration} parameter} string hostname
26313 Hostname of the component.
26316 @deftypevr {@code{int-component-configuration} parameter} string plugin
26317 Plugin you wish to use for the component.
26320 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
26321 Multi-user chat (MUC) is Prosody's module for allowing you to create
26322 hosted chatrooms/conferences for XMPP users.
26324 General information on setting up and using multi-user chatrooms can be found
26325 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
26326 which you should read if you are new to XMPP chatrooms.
26328 See also @url{https://prosody.im/doc/modules/mod_muc}.
26330 Available @code{mod-muc-configuration} fields are:
26332 @deftypevr {@code{mod-muc-configuration} parameter} string name
26333 The name to return in service discovery responses.
26334 Defaults to @samp{"Prosody Chatrooms"}.
26337 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
26338 If @samp{#t}, this will only allow admins to create new chatrooms.
26339 Otherwise anyone can create a room. The value @samp{"local"} restricts room
26340 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
26341 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
26342 restricts to service administrators only.
26343 Defaults to @samp{#f}.
26346 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
26347 Maximum number of history messages that will be sent to the member that has
26348 just joined the room.
26349 Defaults to @samp{20}.
26356 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
26357 External components use XEP-0114, which most standalone components
26358 support. To add an external component, you simply fill the hostname field. See
26359 @url{https://prosody.im/doc/components}.
26360 Defaults to @samp{()}.
26362 Available @code{ext-component-configuration} fields are:
26364 all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
26365 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
26366 Password which the component will use to log in.
26369 @deftypevr {@code{ext-component-configuration} parameter} string hostname
26370 Hostname of the component.
26375 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
26376 Port(s) Prosody listens on for component connections.
26377 Defaults to @samp{(5347)}.
26380 @deftypevr {@code{prosody-configuration} parameter} string component-interface
26381 Interface Prosody listens on for component connections.
26382 Defaults to @samp{"127.0.0.1"}.
26385 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
26386 Raw content that will be added to the configuration file.
26389 It could be that you just want to get a @code{prosody.cfg.lua}
26390 up and running. In that case, you can pass an
26391 @code{opaque-prosody-configuration} record as the value of
26392 @code{prosody-service-type}. As its name indicates, an opaque configuration
26393 does not have easy reflective capabilities.
26394 Available @code{opaque-prosody-configuration} fields are:
26396 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
26397 The prosody package.
26400 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
26401 The contents of the @code{prosody.cfg.lua} to use.
26404 For example, if your @code{prosody.cfg.lua} is just the empty
26405 string, you could instantiate a prosody service like this:
26408 (service prosody-service-type
26409 (opaque-prosody-configuration
26410 (prosody.cfg.lua "")))
26413 @c end of Prosody auto-generated documentation
26415 @subsubheading BitlBee Service
26417 @cindex IRC (Internet Relay Chat)
26418 @cindex IRC gateway
26419 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
26420 interface to a variety of messaging protocols such as XMPP.
26422 @defvr {Scheme Variable} bitlbee-service-type
26423 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
26424 gateway daemon. Its value is a @code{bitlbee-configuration} (see
26427 To have BitlBee listen on port 6667 on localhost, add this line to your
26431 (service bitlbee-service-type)
26435 @deftp {Data Type} bitlbee-configuration
26436 This is the configuration for BitlBee, with the following fields:
26439 @item @code{interface} (default: @code{"127.0.0.1"})
26440 @itemx @code{port} (default: @code{6667})
26441 Listen on the network interface corresponding to the IP address
26442 specified in @var{interface}, on @var{port}.
26444 When @var{interface} is @code{127.0.0.1}, only local clients can
26445 connect; when it is @code{0.0.0.0}, connections can come from any
26446 networking interface.
26448 @item @code{bitlbee} (default: @code{bitlbee})
26449 The BitlBee package to use.
26451 @item @code{plugins} (default: @code{'()})
26452 List of plugin packages to use---e.g., @code{bitlbee-discord}.
26454 @item @code{extra-settings} (default: @code{""})
26455 Configuration snippet added as-is to the BitlBee configuration file.
26459 @subsubheading Quassel Service
26461 @cindex IRC (Internet Relay Chat)
26462 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
26463 meaning that one or more clients can attach to and detach from the
26466 @defvr {Scheme Variable} quassel-service-type
26467 This is the service type for the @url{https://quassel-irc.org/,Quassel}
26468 IRC backend daemon. Its value is a @code{quassel-configuration}
26472 @deftp {Data Type} quassel-configuration
26473 This is the configuration for Quassel, with the following fields:
26476 @item @code{quassel} (default: @code{quassel})
26477 The Quassel package to use.
26479 @item @code{interface} (default: @code{"::,0.0.0.0"})
26480 @item @code{port} (default: @code{4242})
26481 Listen on the network interface(s) corresponding to the IPv4 or IPv6
26482 interfaces specified in the comma delimited @var{interface}, on
26485 @item @code{loglevel} (default: @code{"Info"})
26486 The level of logging desired. Accepted values are Debug, Info, Warning
26491 @node Telephony Services
26492 @subsection Telephony Services
26494 @cindex telephony, services
26495 The @code{(gnu services telephony)} module contains Guix service
26496 definitions for telephony services. Currently it provides the following
26499 @subsubheading Jami
26501 @cindex jami, service
26503 This section describes how to configure a Jami server that can be used
26504 to host video (or audio) conferences, among other uses. The following
26505 example demonstrates how to specify Jami account archives (backups) to
26506 be provisioned automatically:
26509 (service jami-service-type
26510 (jami-configuration
26512 (list (jami-account
26513 (archive "/etc/jami/unencrypted-account-1.gz"))
26515 (archive "/etc/jami/unencrypted-account-2.gz"))))))
26518 When the accounts field is specified, the Jami account files of the
26519 service found under @file{/var/lib/jami} are recreated every time the
26522 Jami accounts and their corresponding backup archives can be generated
26523 using the @code{jami} or @code{jami-gnome} Jami clients. The accounts
26524 should not be password-protected, but it is wise to ensure their files
26525 are only readable by @samp{root}.
26527 The next example shows how to declare that only some contacts should be
26528 allowed to communicate with a given account:
26531 (service jami-service-type
26532 (jami-configuration
26534 (list (jami-account
26535 (archive "/etc/jami/unencrypted-account-1.gz")
26536 (peer-discovery? #t)
26537 (rendezvous-point? #t)
26539 '("1dbcb0f5f37324228235564b79f2b9737e9a008f"
26540 "2dbcb0f5f37324228235564b79f2b9737e9a008f")))))))
26543 In this mode, only the declared @code{allowed-contacts} can initiate
26544 communication with the Jami account. This can be used, for example,
26545 with rendezvous point accounts to create a private video conferencing
26548 To put the system administrator in full control of the conferences
26549 hosted on their system, the Jami service supports the following actions:
26552 # herd doc jami list-actions
26554 list-account-details
26555 list-banned-contacts
26564 The above actions aim to provide the most valuable actions for
26565 moderation purposes, not to cover the whole Jami API. Users wanting to
26566 interact with the Jami daemon from Guile may be interested in
26567 experimenting with the @code{(gnu build jami-service)} module, which
26568 powers the above Shepherd actions.
26570 @c TODO: This should be auto-generated from the doc already defined on
26571 @c the shepherd-actions themselves in (gnu services telephony).
26572 The @code{add-moderator} and @code{ban-contact} actions accept a contact
26573 @emph{fingerprint} (40 characters long hash) as first argument and an
26574 account fingerprint or username as second argument:
26577 # herd add-moderator jami 1dbcb0f5f37324228235564b79f2b9737e9a008f \
26578 f3345f2775ddfe07a4b0d95daea111d15fbc1199
26580 # herd list-moderators jami
26581 Moderators for account f3345f2775ddfe07a4b0d95daea111d15fbc1199:
26582 - 1dbcb0f5f37324228235564b79f2b9737e9a008f
26586 In the case of @code{ban-contact}, the second username argument is
26587 optional; when omitted, the account is banned from all Jami accounts:
26590 # herd ban-contact jami 1dbcb0f5f37324228235564b79f2b9737e9a008f
26592 # herd list-banned-contacts jami
26593 Banned contacts for account f3345f2775ddfe07a4b0d95daea111d15fbc1199:
26594 - 1dbcb0f5f37324228235564b79f2b9737e9a008f
26598 Banned contacts are also stripped from their moderation privileges.
26600 The @code{disable-account} action allows to completely disconnect an
26601 account from the network, making it unreachable, while
26602 @code{enable-account} does the inverse. They accept a single account
26603 username or fingerprint as first argument:
26606 # herd disable-account jami f3345f2775ddfe07a4b0d95daea111d15fbc1199
26608 # herd list-accounts jami
26609 The following Jami accounts are available:
26610 - f3345f2775ddfe07a4b0d95daea111d15fbc1199 (dummy) [disabled]
26614 The @code{list-account-details} action prints the detailed parameters of
26615 each accounts in the Recutils format, which means the @command{recsel}
26616 command can be used to select accounts of interest (@pxref{Selection
26617 Expressions,,,recutils, GNU recutils manual}). Note that period
26618 characters (@samp{.}) found in the account parameter keys are mapped to
26619 underscores (@samp{_}) in the output, to meet the requirements of the
26620 Recutils format. The following example shows how to print the account
26621 fingerprints for all accounts operating in the rendezvous point mode:
26624 # herd list-account-details jami | \
26625 recsel -p Account.username -e 'Account.rendezVous ~ "true"'
26626 Account_username: f3345f2775ddfe07a4b0d95daea111d15fbc1199
26629 The remaining actions should be self-explanatory.
26631 The complete set of available configuration options is detailed below.
26633 @c TODO: Ideally, the following fragments would be auto-generated at
26634 @c build time, so that they needn't be manually duplicated.
26635 @c Auto-generated via (configuration->documentation 'jami-configuration)
26636 @deftp {Data Type} jami-configuration
26637 Available @code{jami-configuration} fields are:
26640 @item @code{libjami} (default: @code{libjami}) (type: package)
26641 The Jami daemon package to use.
26643 @item @code{dbus} (default: @code{dbus-for-jami}) (type: package)
26644 The D-Bus package to use to start the required D-Bus session.
26646 @item @code{nss-certs} (default: @code{nss-certs}) (type: package)
26647 The nss-certs package to use to provide TLS certificates.
26649 @item @code{enable-logging?} (default: @code{#t}) (type: boolean)
26650 Whether to enable logging to syslog.
26652 @item @code{debug?} (default: @code{#f}) (type: boolean)
26653 Whether to enable debug level messages.
26655 @item @code{auto-answer?} (default: @code{#f}) (type: boolean)
26656 Whether to force automatic answer to incoming calls.
26658 @item @code{accounts} (type: maybe-jami-account-list)
26659 A list of Jami accounts to be (re-)provisioned every time the Jami
26660 daemon service starts. When providing this field, the account
26661 directories under @file{/var/lib/jami/} are recreated every time the
26662 service starts, ensuring a consistent state.
26668 @c Auto-generated via (configuration->documentation 'jami-account)
26669 @deftp {Data Type} jami-account
26670 Available @code{jami-account} fields are:
26673 @item @code{archive} (type: string-or-computed-file)
26674 The account archive (backup) file name of the account. This is used to
26675 provision the account when the service starts. The account archive
26676 should @emph{not} be encrypted. It is highly recommended to make it
26677 readable only to the @samp{root} user (i.e., not in the store), to guard
26678 against leaking the secret key material of the Jami account it contains.
26680 @item @code{allowed-contacts} (type: maybe-account-fingerprint-list)
26681 The list of allowed contacts for the account, entered as their 40
26682 characters long fingerprint. Messages or calls from accounts not in
26683 that list will be rejected. When left specified, the configuration of
26684 the account archive is used as-is with respect to contacts and public
26685 inbound calls/messaging allowance, which typically defaults to allow any
26686 contact to communicate with the account.
26688 @item @code{moderators} (type: maybe-account-fingerprint-list)
26689 The list of contacts that should have moderation privileges (to ban,
26690 mute, etc. other users) in rendezvous conferences, entered as their 40
26691 characters long fingerprint. When left unspecified, the configuration
26692 of the account archive is used as-is with respect to moderation, which
26693 typically defaults to allow anyone to moderate.
26695 @item @code{rendezvous-point?} (type: maybe-boolean)
26696 Whether the account should operate in the rendezvous mode. In this
26697 mode, all the incoming audio/video calls are mixed into a conference.
26698 When left unspecified, the value from the account archive prevails.
26700 @item @code{peer-discovery?} (type: maybe-boolean)
26701 Whether peer discovery should be enabled. Peer discovery is used to
26702 discover other OpenDHT nodes on the local network, which can be useful
26703 to maintain communication between devices on such network even when the
26704 connection to the the Internet has been lost. When left unspecified,
26705 the value from the account archive prevails.
26707 @item @code{bootstrap-hostnames} (type: maybe-string-list)
26708 A list of hostnames or IPs pointing to OpenDHT nodes, that should be
26709 used to initially join the OpenDHT network. When left unspecified, the
26710 value from the account archive prevails.
26712 @item @code{name-server-uri} (type: maybe-string)
26713 The URI of the name server to use, that can be used to retrieve the
26714 account fingerprint for a registered username.
26720 @subsubheading Mumble server
26724 @cindex VoIP server
26725 This section describes how to set up and run a
26726 @uref{https://mumble.info, Mumble} server (formerly known as Murmur).
26728 @deftp {Data Type} mumble-server-configuration
26729 The service type for the Mumble server. An example configuration can
26733 (service mumble-server-service-type
26734 (mumble-server-configuration
26736 "Welcome to this Mumble server running on Guix!")
26737 (cert-required? #t) ;disallow text password logins
26738 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
26739 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
26742 After reconfiguring your system, you can manually set the mumble-server
26744 password with the command that is printed during the activation phase.
26746 It is recommended to register a normal Mumble user account
26747 and grant it admin or moderator rights.
26748 You can use the @code{mumble} client to
26749 login as new normal user, register yourself, and log out.
26750 For the next step login with the name @code{SuperUser} use
26751 the @code{SuperUser} password that you set previously,
26752 and grant your newly registered mumble user administrator or moderator
26753 rights and create some channels.
26755 Available @code{mumble-server-configuration} fields are:
26758 @item @code{package} (default: @code{mumble})
26759 Package that contains @code{bin/mumble-server}.
26761 @item @code{user} (default: @code{"mumble-server"})
26762 User who will run the Mumble-Server server.
26764 @item @code{group} (default: @code{"mumble-server"})
26765 Group of the user who will run the mumble-server server.
26767 @item @code{port} (default: @code{64738})
26768 Port on which the server will listen.
26770 @item @code{welcome-text} (default: @code{""})
26771 Welcome text sent to clients when they connect.
26773 @item @code{server-password} (default: @code{""})
26774 Password the clients have to enter in order to connect.
26776 @item @code{max-users} (default: @code{100})
26777 Maximum of users that can be connected to the server at once.
26779 @item @code{max-user-bandwidth} (default: @code{#f})
26780 Maximum voice traffic a user can send per second.
26782 @item @code{database-file} (default: @code{"/var/lib/mumble-server/db.sqlite"})
26783 File name of the sqlite database.
26784 The service's user will become the owner of the directory.
26786 @item @code{log-file} (default: @code{"/var/log/mumble-server/mumble-server.log"})
26787 File name of the log file.
26788 The service's user will become the owner of the directory.
26790 @item @code{autoban-attempts} (default: @code{10})
26791 Maximum number of logins a user can make in @code{autoban-timeframe}
26792 without getting auto banned for @code{autoban-time}.
26794 @item @code{autoban-timeframe} (default: @code{120})
26795 Timeframe for autoban in seconds.
26797 @item @code{autoban-time} (default: @code{300})
26798 Amount of time in seconds for which a client gets banned
26799 when violating the autoban limits.
26801 @item @code{opus-threshold} (default: @code{100})
26802 Percentage of clients that need to support opus
26803 before switching over to opus audio codec.
26805 @item @code{channel-nesting-limit} (default: @code{10})
26806 How deep channels can be nested at maximum.
26808 @item @code{channelname-regex} (default: @code{#f})
26809 A string in form of a Qt regular expression that channel names must conform to.
26811 @item @code{username-regex} (default: @code{#f})
26812 A string in form of a Qt regular expression that user names must conform to.
26814 @item @code{text-message-length} (default: @code{5000})
26815 Maximum size in bytes that a user can send in one text chat message.
26817 @item @code{image-message-length} (default: @code{(* 128 1024)})
26818 Maximum size in bytes that a user can send in one image message.
26820 @item @code{cert-required?} (default: @code{#f})
26821 If it is set to @code{#t} clients that use weak password authentication
26822 will not be accepted. Users must have completed the certificate wizard to join.
26824 @item @code{remember-channel?} (default: @code{#f})
26825 Should mumble-server remember the last channel each user was in when
26826 they disconnected and put them into the remembered channel when they
26829 @item @code{allow-html?} (default: @code{#f})
26830 Should html be allowed in text messages, user comments, and channel descriptions.
26832 @item @code{allow-ping?} (default: @code{#f})
26833 Setting to true exposes the current user count, the maximum user count, and
26834 the server's maximum bandwidth per client to unauthenticated users. In the
26835 Mumble client, this information is shown in the Connect dialog.
26837 Disabling this setting will prevent public listing of the server.
26839 @item @code{bonjour?} (default: @code{#f})
26840 Should the server advertise itself in the local network through the bonjour protocol.
26842 @item @code{send-version?} (default: @code{#f})
26843 Should the mumble-server server version be exposed in ping requests.
26845 @item @code{log-days} (default: @code{31})
26846 Mumble also stores logs in the database, which are accessible via RPC.
26847 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
26848 or -1 to disable logging to the database.
26850 @item @code{obfuscate-ips?} (default: @code{#t})
26851 Should logged ips be obfuscated to protect the privacy of users.
26853 @item @code{ssl-cert} (default: @code{#f})
26854 File name of the SSL/TLS certificate used for encrypted connections.
26857 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
26859 @item @code{ssl-key} (default: @code{#f})
26860 Filepath to the ssl private key used for encrypted connections.
26862 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
26865 @item @code{ssl-dh-params} (default: @code{#f})
26866 File name of a PEM-encoded file with Diffie-Hellman parameters
26867 for the SSL/TLS encryption. Alternatively you set it to
26868 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
26869 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
26871 @item @code{ssl-ciphers} (default: @code{#f})
26872 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
26875 This option is specified using
26876 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
26877 OpenSSL cipher list notation}.
26879 It is recommended that you try your cipher string using
26880 'openssl ciphers <string>' before setting it here, to get a feel for
26881 which cipher suites you will get.
26882 After setting this option, it is recommend that you inspect your Mumble
26883 server log to ensure that Mumble is using the cipher suites that you
26887 Changing this option may impact the backwards compatibility of your
26888 Mumble-Server server, and can remove the ability for older Mumble clients to be able to connect to it.
26891 @item @code{public-registration} (default: @code{#f})
26892 Must be a @code{<mumble-server-public-registration-configuration>}
26893 record or @code{#f}.
26895 You can optionally register your server in the public server list that the
26896 @code{mumble} client shows on startup.
26897 You cannot register your server if you have set a @code{server-password},
26898 or set @code{allow-ping} to @code{#f}.
26900 It might take a few hours until it shows up in the public list.
26902 @item @code{file} (default: @code{#f})
26903 Optional alternative override for this configuration.
26907 @deftp {Data Type} mumble-server-public-registration-configuration
26908 Configuration for public registration of a mumble-server service.
26912 This is a display name for your server. Not to be confused with the hostname.
26914 @item @code{password}
26915 A password to identify your registration.
26916 Subsequent updates will need the same password. Don't lose your password.
26919 This should be a @code{http://} or @code{https://} link to your web
26922 @item @code{hostname} (default: @code{#f})
26923 By default your server will be listed by its IP address.
26924 If it is set your server will be linked by this host name instead.
26928 @quotation Deprecation notice
26929 Due to historical reasons, all of the above @code{mumble-server-}
26930 procedures are also exported with the @code{murmur-} prefix.
26931 It is recommended that you switch to using @code{mumble-server-}
26935 @node File-Sharing Services
26936 @subsection File-Sharing Services
26938 The @code{(gnu services file-sharing)} module provides services that
26939 assist with transferring files over peer-to-peer file-sharing networks.
26941 @subsubheading Transmission Daemon Service
26943 @uref{https://transmissionbt.com/, Transmission} is a flexible
26944 BitTorrent client that offers a variety of graphical and command-line
26945 interfaces. A @code{transmission-daemon-service-type} service provides
26946 Transmission's headless variant, @command{transmission-daemon}, as a
26947 system service, allowing users to share files via BitTorrent even when
26948 they are not logged in.
26950 @deffn {Scheme Variable} transmission-daemon-service-type
26951 The service type for the Transmission Daemon BitTorrent client. Its
26952 value must be a @code{transmission-daemon-configuration} object as in
26956 (service transmission-daemon-service-type
26957 (transmission-daemon-configuration
26958 ;; Restrict access to the RPC ("control") interface
26959 (rpc-authentication-required? #t)
26960 (rpc-username "transmission")
26962 (transmission-password-hash
26963 "transmission" ; desired password
26964 "uKd1uMs9")) ; arbitrary salt value
26966 ;; Accept requests from this and other hosts on the
26968 (rpc-whitelist-enabled? #t)
26969 (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
26971 ;; Limit bandwidth use during work hours
26972 (alt-speed-down (* 1024 2)) ; 2 MB/s
26973 (alt-speed-up 512) ; 512 kB/s
26975 (alt-speed-time-enabled? #t)
26976 (alt-speed-time-day 'weekdays)
26977 (alt-speed-time-begin
26978 (+ (* 60 8) 30)) ; 8:30 am
26979 (alt-speed-time-end
26980 (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
26984 Once the service is started, users can interact with the daemon through
26985 its Web interface (at @code{http://localhost:9091/}) or by using the
26986 @command{transmission-remote} command-line tool, available in the
26987 @code{transmission} package. (Emacs users may want to also consider the
26988 @code{emacs-transmission} package.) Both communicate with the daemon
26989 through its remote procedure call (RPC) interface, which by default is
26990 available to all users on the system; you may wish to change this by
26991 assigning values to the @code{rpc-authentication-required?},
26992 @code{rpc-username} and @code{rpc-password} settings, as shown in the
26993 example above and documented further below.
26995 The value for @code{rpc-password} must be a password hash of the type
26996 generated and used by Transmission clients. This can be copied verbatim
26997 from an existing @file{settings.json} file, if another Transmission
26998 client is already being used. Otherwise, the
26999 @code{transmission-password-hash} and @code{transmission-random-salt}
27000 procedures provided by this module can be used to obtain a suitable hash
27003 @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
27004 Returns a string containing the result of hashing @var{password}
27005 together with @var{salt}, in the format recognized by Transmission
27006 clients for their @code{rpc-password} configuration setting.
27008 @var{salt} must be an eight-character string. The
27009 @code{transmission-random-salt} procedure can be used to generate a
27010 suitable salt value at random.
27013 @deffn {Scheme Procedure} transmission-random-salt
27014 Returns a string containing a random, eight-character salt value of the
27015 type generated and used by Transmission clients, suitable for passing to
27016 the @code{transmission-password-hash} procedure.
27019 These procedures are accessible from within a Guile REPL started with
27020 the @command{guix repl} command (@pxref{Invoking guix repl}). This is
27021 useful for obtaining a random salt value to provide as the second
27022 parameter to `transmission-password-hash`, as in this example session:
27026 scheme@@(guix-user)> ,use (gnu services file-sharing)
27027 scheme@@(guix-user)> (transmission-random-salt)
27031 Alternatively, a complete password hash can generated in a single step:
27034 scheme@@(guix-user)> (transmission-password-hash "transmission"
27035 (transmission-random-salt))
27036 $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
27039 The resulting string can be used as-is for the value of
27040 @code{rpc-password}, allowing the password to be kept hidden even in the
27041 operating-system configuration.
27043 Torrent files downloaded by the daemon are directly accessible only to
27044 users in the ``transmission'' user group, who receive read-only access
27045 to the directory specified by the @code{download-dir} configuration
27046 setting (and also the directory specified by @code{incomplete-dir}, if
27047 @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
27048 moved to another directory or deleted altogether using
27049 @command{transmission-remote} with its @code{--move} and
27050 @code{--remove-and-delete} options.
27052 If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
27053 the ``transmission'' group are able also to place @file{.torrent} files
27054 in the directory specified by @code{watch-dir} to have the corresponding
27055 torrents added by the daemon. (The @code{trash-original-torrent-files?}
27056 setting controls whether the daemon deletes these files after processing
27059 Some of the daemon's configuration settings can be changed temporarily
27060 by @command{transmission-remote} and similar tools. To undo these
27061 changes, use the service's @code{reload} action to have the daemon
27062 reload its settings from disk:
27065 # herd reload transmission-daemon
27068 The full set of available configuration settings is defined by the
27069 @code{transmission-daemon-configuration} data type.
27071 @deftp {Data Type} transmission-daemon-configuration
27072 The data type representing configuration settings for Transmission
27073 Daemon. These correspond directly to the settings recognized by
27074 Transmission clients in their @file{settings.json} file.
27077 @c The following documentation was initially generated by
27078 @c (generate-transmission-daemon-documentation) in (gnu services
27079 @c file-sharing). Manually maintained documentation is better, so we
27080 @c shouldn't hesitate to edit below as needed. However if the change
27081 @c you want to make to this documentation can be done in an automated
27082 @c way, it's probably easier to change (generate-documentation) than to
27083 @c make it below and have to deal with the churn as Transmission Daemon
27086 @c %start of fragment
27088 Available @code{transmission-daemon-configuration} fields are:
27090 @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
27091 The Transmission package to use.
27095 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
27096 The period, in seconds, to wait when stopping the service for
27097 @command{transmission-daemon} to exit before killing its process. This
27098 allows the daemon time to complete its housekeeping and send a final
27099 update to trackers as it shuts down. On slow hosts, or hosts with a
27100 slow network connection, this value may need to be increased.
27102 Defaults to @samp{10}.
27106 @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
27107 The directory to which torrent files are downloaded.
27109 Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
27113 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
27114 If @code{#t}, files will be held in @code{incomplete-dir} while their
27115 torrent is being downloaded, then moved to @code{download-dir} once the
27116 torrent is complete. Otherwise, files for all torrents (including those
27117 still being downloaded) will be placed in @code{download-dir}.
27119 Defaults to @samp{#f}.
27123 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
27124 The directory in which files from incompletely downloaded torrents will
27125 be held when @code{incomplete-dir-enabled?} is @code{#t}.
27127 Defaults to @samp{disabled}.
27131 @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
27132 The file mode creation mask used for downloaded files. (See the
27133 @command{umask} man page for more information.)
27135 Defaults to @samp{18}.
27139 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
27140 When @code{#t}, ``.part'' is appended to the name of partially
27143 Defaults to @samp{#t}.
27147 @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
27148 The mode by which space should be preallocated for downloaded files, one
27149 of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
27150 Specifying @code{full} will minimize disk fragmentation at a cost to
27151 file-creation speed.
27153 Defaults to @samp{fast}.
27157 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
27158 If @code{#t}, the directory specified by @code{watch-dir} will be
27159 watched for new @file{.torrent} files and the torrents they describe
27160 added automatically (and the original files removed, if
27161 @code{trash-original-torrent-files?} is @code{#t}).
27163 Defaults to @samp{#f}.
27167 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
27168 The directory to be watched for @file{.torrent} files indicating new
27169 torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
27171 Defaults to @samp{disabled}.
27175 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
27176 When @code{#t}, @file{.torrent} files will be deleted from the watch
27177 directory once their torrent has been added (see
27178 @code{watch-directory-enabled?}).
27180 Defaults to @samp{#f}.
27184 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
27185 When @code{#t}, the daemon's download speed will be limited to the rate
27186 specified by @code{speed-limit-down}.
27188 Defaults to @samp{#f}.
27192 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
27193 The default global-maximum download speed, in kilobytes per second.
27195 Defaults to @samp{100}.
27199 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
27200 When @code{#t}, the daemon's upload speed will be limited to the rate
27201 specified by @code{speed-limit-up}.
27203 Defaults to @samp{#f}.
27207 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
27208 The default global-maximum upload speed, in kilobytes per second.
27210 Defaults to @samp{100}.
27214 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
27215 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
27216 @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
27217 @code{speed-limit-up}, if they are enabled) to constrain the daemon's
27218 bandwidth usage. This can be scheduled to occur automatically at
27219 certain times during the week; see @code{alt-speed-time-enabled?}.
27221 Defaults to @samp{#f}.
27225 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
27226 The alternate global-maximum download speed, in kilobytes per second.
27228 Defaults to @samp{50}.
27232 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
27233 The alternate global-maximum upload speed, in kilobytes per second.
27235 Defaults to @samp{50}.
27239 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
27240 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
27241 @code{alt-speed-up} will be enabled automatically during the periods
27242 specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
27243 @code{alt-time-speed-end}.
27245 Defaults to @samp{#f}.
27249 @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
27250 The days of the week on which the alternate-speed schedule should be
27251 used, specified either as a list of days (@code{sunday}, @code{monday},
27252 and so on) or using one of the symbols @code{weekdays}, @code{weekends}
27255 Defaults to @samp{all}.
27259 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
27260 The time of day at which to enable the alternate speed limits, expressed
27261 as a number of minutes since midnight.
27263 Defaults to @samp{540}.
27267 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
27268 The time of day at which to disable the alternate speed limits,
27269 expressed as a number of minutes since midnight.
27271 Defaults to @samp{1020}.
27275 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
27276 The IP address at which to listen for peer connections, or ``0.0.0.0''
27277 to listen at all available IP addresses.
27279 Defaults to @samp{"0.0.0.0"}.
27283 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
27284 The IPv6 address at which to listen for peer connections, or ``::'' to
27285 listen at all available IPv6 addresses.
27287 Defaults to @samp{"::"}.
27291 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
27292 If @code{#t}, when the daemon starts it will select a port at random on
27293 which to listen for peer connections, from the range specified
27294 (inclusively) by @code{peer-port-random-low} and
27295 @code{peer-port-random-high}. Otherwise, it listens on the port
27296 specified by @code{peer-port}.
27298 Defaults to @samp{#f}.
27302 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
27303 The lowest selectable port number when @code{peer-port-random-on-start?}
27306 Defaults to @samp{49152}.
27310 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
27311 The highest selectable port number when @code{peer-port-random-on-start}
27314 Defaults to @samp{65535}.
27318 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
27319 The port on which to listen for peer connections when
27320 @code{peer-port-random-on-start?} is @code{#f}.
27322 Defaults to @samp{51413}.
27326 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
27327 If @code{#t}, the daemon will attempt to configure port-forwarding on an
27328 upstream gateway automatically using @acronym{UPnP} and
27331 Defaults to @samp{#t}.
27335 @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
27336 The encryption preference for peer connections, one of
27337 @code{prefer-unencrypted-connections},
27338 @code{prefer-encrypted-connections} or
27339 @code{require-encrypted-connections}.
27341 Defaults to @samp{prefer-encrypted-connections}.
27345 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
27346 The TCP congestion-control algorithm to use for peer connections,
27347 specified using a string recognized by the operating system in calls to
27348 @code{setsockopt}. When left unspecified, the operating-system default
27351 Note that on GNU/Linux systems, the kernel must be configured to allow
27352 processes to use a congestion-control algorithm not in the default set;
27353 otherwise, it will deny these requests with ``Operation not permitted''.
27354 To see which algorithms are available on your system and which are
27355 currently permitted for use, look at the contents of the files
27356 @file{tcp_available_congestion_control} and
27357 @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
27360 As an example, to have Transmission Daemon use
27361 @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
27362 congestion-control algorithm}, you'll need to modify your kernel
27363 configuration to build in support for the algorithm, then update your
27364 operating-system configuration to allow its use by adding a
27365 @code{sysctl-service-type} service (or updating the existing one's
27366 configuration) with lines like the following:
27369 (service sysctl-service-type
27370 (sysctl-configuration
27372 ("net.ipv4.tcp_allowed_congestion_control" .
27373 "reno cubic lp"))))
27376 The Transmission Daemon configuration can then be updated with
27379 (peer-congestion-algorithm "lp")
27382 and the system reconfigured to have the changes take effect.
27384 Defaults to @samp{disabled}.
27388 @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
27389 The type of service to request in outgoing @acronym{TCP} packets, one of
27390 @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
27391 @code{reliability}.
27393 Defaults to @samp{default}.
27397 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
27398 The global limit on the number of connected peers.
27400 Defaults to @samp{200}.
27404 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
27405 The per-torrent limit on the number of connected peers.
27407 Defaults to @samp{50}.
27411 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
27412 The maximum number of peers to which the daemon will upload data
27413 simultaneously for each torrent.
27415 Defaults to @samp{14}.
27419 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
27420 The maximum lifespan, in hours, of the peer ID associated with each
27421 public torrent before it is regenerated.
27423 Defaults to @samp{6}.
27427 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
27428 When @code{#t}, the daemon will ignore peers mentioned in the blocklist
27429 it has most recently downloaded from @code{blocklist-url}.
27431 Defaults to @samp{#f}.
27435 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
27436 The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
27437 @file{.dat} format) to be periodically downloaded and applied when
27438 @code{blocklist-enabled?} is @code{#t}.
27440 Defaults to @samp{disabled}.
27444 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
27445 If @code{#t}, the daemon will be limited to downloading at most
27446 @code{download-queue-size} non-stalled torrents simultaneously.
27448 Defaults to @samp{#t}.
27452 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
27453 The size of the daemon's download queue, which limits the number of
27454 non-stalled torrents it will download at any one time when
27455 @code{download-queue-enabled?} is @code{#t}.
27457 Defaults to @samp{5}.
27461 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
27462 If @code{#t}, the daemon will be limited to seeding at most
27463 @code{seed-queue-size} non-stalled torrents simultaneously.
27465 Defaults to @samp{#f}.
27469 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
27470 The size of the daemon's seed queue, which limits the number of
27471 non-stalled torrents it will seed at any one time when
27472 @code{seed-queue-enabled?} is @code{#t}.
27474 Defaults to @samp{10}.
27478 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
27479 When @code{#t}, the daemon will consider torrents for which it has not
27480 shared data in the past @code{queue-stalled-minutes} minutes to be
27481 stalled and not count them against its @code{download-queue-size} and
27482 @code{seed-queue-size} limits.
27484 Defaults to @samp{#t}.
27488 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
27489 The maximum period, in minutes, a torrent may be idle before it is
27490 considered to be stalled, when @code{queue-stalled-enabled?} is
27493 Defaults to @samp{30}.
27497 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
27498 When @code{#t}, a torrent being seeded will automatically be paused once
27499 it reaches the ratio specified by @code{ratio-limit}.
27501 Defaults to @samp{#f}.
27505 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
27506 The ratio at which a torrent being seeded will be paused, when
27507 @code{ratio-limit-enabled?} is @code{#t}.
27509 Defaults to @samp{2.0}.
27513 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
27514 When @code{#t}, a torrent being seeded will automatically be paused once
27515 it has been idle for @code{idle-seeding-limit} minutes.
27517 Defaults to @samp{#f}.
27521 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
27522 The maximum period, in minutes, a torrent being seeded may be idle
27523 before it is paused, when @code{idle-seeding-limit-enabled?} is
27526 Defaults to @samp{30}.
27530 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
27531 Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
27532 hash table (@acronym{DHT}) protocol}, which supports the use of
27533 trackerless torrents.
27535 Defaults to @samp{#t}.
27539 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
27540 Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
27541 peer discovery} (@acronym{LPD}), which allows the discovery of peers on
27542 the local network and may reduce the amount of data sent over the public
27545 Defaults to @samp{#f}.
27549 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
27550 Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
27551 (@acronym{PEX}), which reduces the daemon's reliance on external
27552 trackers and may improve its performance.
27554 Defaults to @samp{#t}.
27558 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
27559 Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
27560 transport protocol} (@acronym{uTP}), which aims to reduce the impact of
27561 BitTorrent traffic on other users of the local network while maintaining
27562 full utilization of the available bandwidth.
27564 Defaults to @samp{#t}.
27568 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
27569 If @code{#t}, enable the remote procedure call (@acronym{RPC})
27570 interface, which allows remote control of the daemon via its Web
27571 interface, the @command{transmission-remote} command-line client, and
27574 Defaults to @samp{#t}.
27578 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
27579 The IP address at which to listen for @acronym{RPC} connections, or
27580 ``0.0.0.0'' to listen at all available IP addresses.
27582 Defaults to @samp{"0.0.0.0"}.
27586 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
27587 The port on which to listen for @acronym{RPC} connections.
27589 Defaults to @samp{9091}.
27593 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
27594 The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
27596 Defaults to @samp{"/transmission/"}.
27600 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
27601 When @code{#t}, clients must authenticate (see @code{rpc-username} and
27602 @code{rpc-password}) when using the @acronym{RPC} interface. Note this
27603 has the side effect of disabling host-name whitelisting (see
27604 @code{rpc-host-whitelist-enabled?}.
27606 Defaults to @samp{#f}.
27610 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
27611 The username required by clients to access the @acronym{RPC} interface
27612 when @code{rpc-authentication-required?} is @code{#t}.
27614 Defaults to @samp{disabled}.
27618 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
27619 The password required by clients to access the @acronym{RPC} interface
27620 when @code{rpc-authentication-required?} is @code{#t}. This must be
27621 specified using a password hash in the format recognized by Transmission
27622 clients, either copied from an existing @file{settings.json} file or
27623 generated using the @code{transmission-password-hash} procedure.
27625 Defaults to @samp{disabled}.
27629 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
27630 When @code{#t}, @acronym{RPC} requests will be accepted only when they
27631 originate from an address specified in @code{rpc-whitelist}.
27633 Defaults to @samp{#t}.
27637 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
27638 The list of IP and IPv6 addresses from which @acronym{RPC} requests will
27639 be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
27640 may be specified using @samp{*}.
27642 Defaults to @samp{("127.0.0.1" "::1")}.
27646 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
27647 When @code{#t}, @acronym{RPC} requests will be accepted only when they
27648 are addressed to a host named in @code{rpc-host-whitelist}. Note that
27649 requests to ``localhost'' or ``localhost.'', or to a numeric address,
27650 are always accepted regardless of these settings.
27652 Note also this functionality is disabled when
27653 @code{rpc-authentication-required?} is @code{#t}.
27655 Defaults to @samp{#t}.
27659 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
27660 The list of host names recognized by the @acronym{RPC} server when
27661 @code{rpc-host-whitelist-enabled?} is @code{#t}.
27663 Defaults to @samp{()}.
27667 @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
27668 The minimum severity level of messages to be logged (to
27669 @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
27670 logging), @code{error}, @code{info} and @code{debug}.
27672 Defaults to @samp{info}.
27676 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
27677 When @code{#t}, torrents are started as soon as they are added;
27678 otherwise, they are added in ``paused'' state.
27680 Defaults to @samp{#t}.
27684 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
27685 When @code{#t}, the script specified by
27686 @code{script-torrent-done-filename} will be invoked each time a torrent
27689 Defaults to @samp{#f}.
27693 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
27694 A file name or file-like object specifying a script to run each time a
27695 torrent completes, when @code{script-torrent-done-enabled?} is
27698 Defaults to @samp{disabled}.
27702 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
27703 When @code{#t}, the daemon will scrape trackers for a torrent even when
27704 the torrent is paused.
27706 Defaults to @samp{#t}.
27710 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
27711 The amount of memory, in megabytes, to allocate for the daemon's
27712 in-memory cache. A larger value may increase performance by reducing
27713 the frequency of disk I/O.
27715 Defaults to @samp{4}.
27719 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
27720 When @code{#t}, the daemon will try to improve I/O performance by
27721 hinting to the operating system which data is likely to be read next
27722 from disk to satisfy requests from peers.
27724 Defaults to @samp{#t}.
27729 @c %end of fragment
27733 @node Monitoring Services
27734 @subsection Monitoring Services
27736 @subsubheading Tailon Service
27738 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
27739 viewing and searching log files.
27741 The following example will configure the service with default values.
27742 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
27745 (service tailon-service-type)
27748 The following example customises more of the Tailon configuration,
27749 adding @command{sed} to the list of allowed commands.
27752 (service tailon-service-type
27753 (tailon-configuration
27755 (tailon-configuration-file
27756 (allowed-commands '("tail" "grep" "awk" "sed"))))))
27760 @deftp {Data Type} tailon-configuration
27761 Data type representing the configuration of Tailon.
27762 This type has the following parameters:
27765 @item @code{config-file} (default: @code{(tailon-configuration-file)})
27766 The configuration file to use for Tailon. This can be set to a
27767 @dfn{tailon-configuration-file} record value, or any gexp
27768 (@pxref{G-Expressions}).
27770 For example, to instead use a local file, the @code{local-file} function
27774 (service tailon-service-type
27775 (tailon-configuration
27776 (config-file (local-file "./my-tailon.conf"))))
27779 @item @code{package} (default: @code{tailon})
27780 The tailon package to use.
27785 @deftp {Data Type} tailon-configuration-file
27786 Data type representing the configuration options for Tailon.
27787 This type has the following parameters:
27790 @item @code{files} (default: @code{(list "/var/log")})
27791 List of files to display. The list can include strings for a single file
27792 or directory, or a list, where the first item is the name of a
27793 subsection, and the remaining items are the files or directories in that
27796 @item @code{bind} (default: @code{"localhost:8080"})
27797 Address and port to which Tailon should bind on.
27799 @item @code{relative-root} (default: @code{#f})
27800 URL path to use for Tailon, set to @code{#f} to not use a path.
27802 @item @code{allow-transfers?} (default: @code{#t})
27803 Allow downloading the log files in the web interface.
27805 @item @code{follow-names?} (default: @code{#t})
27806 Allow tailing of not-yet existent files.
27808 @item @code{tail-lines} (default: @code{200})
27809 Number of lines to read initially from each file.
27811 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
27812 Commands to allow running. By default, @code{sed} is disabled.
27814 @item @code{debug?} (default: @code{#f})
27815 Set @code{debug?} to @code{#t} to show debug messages.
27817 @item @code{wrap-lines} (default: @code{#t})
27818 Initial line wrapping state in the web interface. Set to @code{#t} to
27819 initially wrap lines (the default), or to @code{#f} to initially not
27822 @item @code{http-auth} (default: @code{#f})
27823 HTTP authentication type to use. Set to @code{#f} to disable
27824 authentication (the default). Supported values are @code{"digest"} or
27827 @item @code{users} (default: @code{#f})
27828 If HTTP authentication is enabled (see @code{http-auth}), access will be
27829 restricted to the credentials provided here. To configure users, use a
27830 list of pairs, where the first element of the pair is the username, and
27831 the 2nd element of the pair is the password.
27834 (tailon-configuration-file
27835 (http-auth "basic")
27836 (users '(("user1" . "password1")
27837 ("user2" . "password2"))))
27844 @subsubheading Darkstat Service
27846 Darkstat is a packet sniffer that captures network traffic, calculates
27847 statistics about usage, and serves reports over HTTP.
27849 @defvar {Scheme Variable} darkstat-service-type
27850 This is the service type for the
27851 @uref{https://unix4lyfe.org/darkstat/, darkstat}
27852 service, its value must be a @code{darkstat-configuration} record as in
27856 (service darkstat-service-type
27857 (darkstat-configuration
27858 (interface "eno1")))
27862 @deftp {Data Type} darkstat-configuration
27863 Data type representing the configuration of @command{darkstat}.
27866 @item @code{package} (default: @code{darkstat})
27867 The darkstat package to use.
27869 @item @code{interface}
27870 Capture traffic on the specified network interface.
27872 @item @code{port} (default: @code{"667"})
27873 Bind the web interface to the specified port.
27875 @item @code{bind-address} (default: @code{"127.0.0.1"})
27876 Bind the web interface to the specified address.
27878 @item @code{base} (default: @code{"/"})
27879 Specify the path of the base URL@. This can be useful if
27880 @command{darkstat} is accessed via a reverse proxy.
27885 @anchor{prometheus-node-exporter}
27886 @subsubheading Prometheus Node Exporter Service
27887 @cindex prometheus-node-exporter
27889 The Prometheus ``node exporter'' makes hardware and operating system statistics
27890 provided by the Linux kernel available for the Prometheus monitoring system.
27891 This service should be deployed on all physical nodes and virtual machines,
27892 where monitoring these statistics is desirable.
27894 @defvar {Scheme variable} prometheus-node-exporter-service-type
27895 This is the service type for the
27896 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
27897 service, its value must be a @code{prometheus-node-exporter-configuration}.
27900 (service prometheus-node-exporter-service-type)
27904 @deftp {Data Type} prometheus-node-exporter-configuration
27905 Data type representing the configuration of @command{node_exporter}.
27908 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
27909 The prometheus-node-exporter package to use.
27911 @item @code{web-listen-address} (default: @code{":9100"})
27912 Bind the web interface to the specified address.
27914 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
27915 This directory can be used to export metrics specific to this machine.
27916 Files containing metrics in the text format, with the filename ending in
27917 @code{.prom} should be placed in this directory.
27919 @item @code{extra-options} (default: @code{'()})
27920 Extra options to pass to the Prometheus node exporter.
27925 @subsubheading Zabbix server
27926 @cindex zabbix zabbix-server
27927 Zabbix is a high performance monitoring system that can collect data from a
27928 variety of sources and provide the results in a web-based interface. Alerting
27929 and reporting is built-in, as well as @dfn{templates} for common operating
27930 system metrics such as network utilization, CPU load, and disk space consumption.
27932 This service provides the central Zabbix monitoring service; you also need
27933 @ref{zabbix-front-end,@code{zabbix-front-end-service-type}} to configure Zabbix
27934 and display results, and optionally @ref{zabbix-agent,
27935 @code{zabbix-agent-service-type}} on machines that should be monitored (other
27936 data sources are supported, such as @ref{prometheus-node-exporter,
27937 Prometheus Node Exporter}).
27939 @defvar {Scheme variable} zabbix-server-service-type
27940 This is the service type for the Zabbix server service. Its value must be a
27941 @code{zabbix-server-configuration} record, shown below.
27944 @c %start of fragment
27946 @deftp {Data Type} zabbix-server-configuration
27947 Available @code{zabbix-server-configuration} fields are:
27950 @item @code{zabbix-server} (default: @code{zabbix-server}) (type: file-like)
27951 The zabbix-server package.
27953 @item @code{user} (default: @code{"zabbix"}) (type: string)
27954 User who will run the Zabbix server.
27956 @item @code{group} (default: @code{"zabbix"}) (type: group)
27957 Group who will run the Zabbix server.
27959 @item @code{db-host} (default: @code{"127.0.0.1"}) (type: string)
27960 Database host name.
27962 @item @code{db-name} (default: @code{"zabbix"}) (type: string)
27965 @item @code{db-user} (default: @code{"zabbix"}) (type: string)
27968 @item @code{db-password} (default: @code{""}) (type: string)
27969 Database password. Please, use @code{include-files} with
27970 @code{DBPassword=SECRET} inside a specified file instead.
27972 @item @code{db-port} (default: @code{5432}) (type: number)
27975 @item @code{log-type} (default: @code{""}) (type: string)
27976 Specifies where log messages are written to:
27980 @item @code{system} - syslog.
27982 @item @code{file} - file specified with @code{log-file} parameter.
27984 @item @code{console} - standard output.
27988 @item @code{log-file} (default: @code{"/var/log/zabbix/server.log"}) (type: string)
27989 Log file name for @code{log-type} @code{file} parameter.
27991 @item @code{pid-file} (default: @code{"/var/run/zabbix/zabbix_server.pid"}) (type: string)
27994 @item @code{ssl-ca-location} (default: @code{"/etc/ssl/certs/ca-certificates.crt"}) (type: string)
27995 The location of certificate authority (CA) files for SSL server
27996 certificate verification.
27998 @item @code{ssl-cert-location} (default: @code{"/etc/ssl/certs"}) (type: string)
27999 Location of SSL client certificates.
28001 @item @code{extra-options} (default: @code{""}) (type: extra-options)
28002 Extra options will be appended to Zabbix server configuration file.
28004 @item @code{include-files} (default: @code{()}) (type: include-files)
28005 You may include individual files or all files in a directory in the
28006 configuration file.
28013 @c %end of fragment
28015 @anchor{zabbix-agent}
28016 @subsubheading Zabbix agent
28017 @cindex zabbix zabbix-agent
28019 The Zabbix agent gathers information about the running system for the Zabbix
28020 monitoring server. It has a variety of built-in checks, and can be extended
28022 @uref{https://www.zabbix.com/documentation/current/en/manual/config/items/userparameters,
28023 @dfn{user parameters}}.
28025 @defvar {Scheme variable} zabbix-agent-service-type
28026 This is the service type for the Zabbix agent service. Its value must be a
28027 @code{zabbix-agent-configuration} record, shown below.
28030 @c %start of fragment
28032 @deftp {Data Type} zabbix-agent-configuration
28033 Available @code{zabbix-agent-configuration} fields are:
28036 @item @code{zabbix-agent} (default: @code{zabbix-agentd}) (type: file-like)
28037 The zabbix-agent package.
28039 @item @code{user} (default: @code{"zabbix"}) (type: string)
28040 User who will run the Zabbix agent.
28042 @item @code{group} (default: @code{"zabbix"}) (type: group)
28043 Group who will run the Zabbix agent.
28045 @item @code{hostname} (default: @code{""}) (type: string)
28046 Unique, case sensitive hostname which is required for active checks and
28047 must match hostname as configured on the server.
28049 @item @code{log-type} (default: @code{""}) (type: string)
28050 Specifies where log messages are written to:
28054 @code{system} - syslog.
28056 @item @code{file} - file specified with
28057 @code{log-file} parameter.
28059 @item @code{console} - standard output.
28063 @item @code{log-file} (default: @code{"/var/log/zabbix/agent.log"}) (type: string)
28064 Log file name for @code{log-type} @code{file} parameter.
28066 @item @code{pid-file} (default: @code{"/var/run/zabbix/zabbix_agent.pid"}) (type: string)
28069 @item @code{server} (default: @code{("127.0.0.1")}) (type: list)
28070 List of IP addresses, optionally in CIDR notation, or hostnames of
28071 Zabbix servers and Zabbix proxies. Incoming connections will be
28072 accepted only from the hosts listed here.
28074 @item @code{server-active} (default: @code{("127.0.0.1")}) (type: list)
28075 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
28076 proxies for active checks. If port is not specified, default port is
28077 used. If this parameter is not specified, active checks are disabled.
28079 @item @code{extra-options} (default: @code{""}) (type: extra-options)
28080 Extra options will be appended to Zabbix server configuration file.
28082 @item @code{include-files} (default: @code{()}) (type: include-files)
28083 You may include individual files or all files in a directory in the
28084 configuration file.
28091 @c %end of fragment
28093 @anchor{zabbix-front-end}
28094 @subsubheading Zabbix front-end
28095 @cindex zabbix zabbix-front-end
28097 The Zabbix front-end provides a web interface to Zabbix. It does not need
28098 to run on the same machine as the Zabbix server. This service works by
28099 extending the @ref{PHP-FPM} and @ref{NGINX} services with the configuration
28100 necessary for loading the Zabbix user interface.
28102 @defvar {Scheme variable} zabbix-front-end-service-type
28103 This is the service type for the Zabbix web frontend. Its value must be a
28104 @code{zabbix-front-end-configuration} record, shown below.
28107 @c %start of fragment
28109 @deftp {Data Type} zabbix-front-end-configuration
28110 Available @code{zabbix-front-end-configuration} fields are:
28113 @item @code{zabbix-server} (default: @code{zabbix-server}) (type: file-like)
28114 The Zabbix server package to use.
28116 @item @code{nginx} (default: @code{()}) (type: list)
28117 List of @ref{nginx-server-configuration,@code{nginx-server-configuration}}
28118 blocks for the Zabbix front-end. When empty, a default that listens on
28121 @item @code{db-host} (default: @code{"localhost"}) (type: string)
28122 Database host name.
28124 @item @code{db-port} (default: @code{5432}) (type: number)
28127 @item @code{db-name} (default: @code{"zabbix"}) (type: string)
28130 @item @code{db-user} (default: @code{"zabbix"}) (type: string)
28133 @item @code{db-password} (default: @code{""}) (type: string)
28134 Database password. Please, use @code{db-secret-file} instead.
28136 @item @code{db-secret-file} (default: @code{""}) (type: string)
28137 Secret file which will be appended to @file{zabbix.conf.php} file. This
28138 file contains credentials for use by Zabbix front-end. You are expected
28139 to create it manually.
28141 @item @code{zabbix-host} (default: @code{"localhost"}) (type: string)
28142 Zabbix server hostname.
28144 @item @code{zabbix-port} (default: @code{10051}) (type: number)
28145 Zabbix server port.
28152 @c %end of fragment
28154 @node Kerberos Services
28155 @subsection Kerberos Services
28158 The @code{(gnu services kerberos)} module provides services relating to
28159 the authentication protocol @dfn{Kerberos}.
28161 @subsubheading Krb5 Service
28163 Programs using a Kerberos client library normally
28164 expect a configuration file in @file{/etc/krb5.conf}.
28165 This service generates such a file from a definition provided in the
28166 operating system declaration.
28167 It does not cause any daemon to be started.
28169 No ``keytab'' files are provided by this service---you must explicitly create them.
28170 This service is known to work with the MIT client library, @code{mit-krb5}.
28171 Other implementations have not been tested.
28173 @defvr {Scheme Variable} krb5-service-type
28174 A service type for Kerberos 5 clients.
28178 Here is an example of its use:
28180 (service krb5-service-type
28181 (krb5-configuration
28182 (default-realm "EXAMPLE.COM")
28183 (allow-weak-crypto? #t)
28186 (name "EXAMPLE.COM")
28187 (admin-server "groucho.example.com")
28188 (kdc "karl.example.com"))
28191 (admin-server "kerb-admin.argrx.edu")
28192 (kdc "keys.argrx.edu"))))))
28196 This example provides a Kerberos@tie{}5 client configuration which:
28198 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
28199 of which have distinct administration servers and key distribution centers;
28200 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
28201 specified by clients;
28202 @item Accepts services which only support encryption types known to be weak.
28205 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
28206 Only the most commonly used ones are described here.
28207 For a full list, and more detailed explanation of each, see the MIT
28208 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
28212 @deftp {Data Type} krb5-realm
28213 @cindex realm, kerberos
28216 This field is a string identifying the name of the realm.
28217 A common convention is to use the fully qualified DNS name of your organization,
28218 converted to upper case.
28220 @item @code{admin-server}
28221 This field is a string identifying the host where the administration server is
28225 This field is a string identifying the key distribution center
28230 @deftp {Data Type} krb5-configuration
28233 @item @code{allow-weak-crypto?} (default: @code{#f})
28234 If this flag is @code{#t} then services which only offer encryption algorithms
28235 known to be weak will be accepted.
28237 @item @code{default-realm} (default: @code{#f})
28238 This field should be a string identifying the default Kerberos
28239 realm for the client.
28240 You should set this field to the name of your Kerberos realm.
28241 If this value is @code{#f}
28242 then a realm must be specified with every Kerberos principal when invoking programs
28243 such as @command{kinit}.
28245 @item @code{realms}
28246 This should be a non-empty list of @code{krb5-realm} objects, which clients may
28248 Normally, one of them will have a @code{name} field matching the @code{default-realm}
28254 @subsubheading PAM krb5 Service
28257 The @code{pam-krb5} service allows for login authentication and password
28258 management via Kerberos.
28259 You will need this service if you want PAM enabled applications to authenticate
28260 users using Kerberos.
28262 @defvr {Scheme Variable} pam-krb5-service-type
28263 A service type for the Kerberos 5 PAM module.
28266 @deftp {Data Type} pam-krb5-configuration
28267 Data type representing the configuration of the Kerberos 5 PAM module.
28268 This type has the following parameters:
28270 @item @code{pam-krb5} (default: @code{pam-krb5})
28271 The pam-krb5 package to use.
28273 @item @code{minimum-uid} (default: @code{1000})
28274 The smallest user ID for which Kerberos authentications should be attempted.
28275 Local accounts with lower values will silently fail to authenticate.
28280 @node LDAP Services
28281 @subsection LDAP Services
28283 @cindex nslcd, LDAP service
28285 The @code{(gnu services authentication)} module provides the
28286 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
28287 server. In addition to configuring the service itself, you may want to add
28288 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
28289 Switch} for detailed information.
28291 Here is a simple operating system declaration with a default configuration of
28292 the @code{nslcd-service-type} and a Name Service Switch configuration that
28293 consults the @code{ldap} name service last:
28296 (use-service-modules authentication)
28297 (use-modules (gnu system nss))
28303 (service nslcd-service-type)
28304 (service dhcp-client-service-type)
28306 (name-service-switch
28307 (let ((services (list (name-service (name "db"))
28308 (name-service (name "files"))
28309 (name-service (name "ldap")))))
28310 (name-service-switch
28311 (inherit %mdns-host-lookup-nss)
28312 (password services)
28315 (netgroup services)
28316 (gshadow services)))))
28319 @c %start of generated documentation for nslcd-configuration
28321 Available @code{nslcd-configuration} fields are:
28323 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
28324 The @code{nss-pam-ldapd} package to use.
28328 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
28329 The number of threads to start that can handle requests and perform LDAP
28330 queries. Each thread opens a separate connection to the LDAP server.
28331 The default is to start 5 threads.
28333 Defaults to @samp{disabled}.
28337 @deftypevr {@code{nslcd-configuration} parameter} string uid
28338 This specifies the user id with which the daemon should be run.
28340 Defaults to @samp{"nslcd"}.
28344 @deftypevr {@code{nslcd-configuration} parameter} string gid
28345 This specifies the group id with which the daemon should be run.
28347 Defaults to @samp{"nslcd"}.
28351 @deftypevr {@code{nslcd-configuration} parameter} log-option log
28352 This option controls the way logging is done via a list containing
28353 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
28354 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
28355 argument is optional and specifies the log level. The log level may be
28356 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
28357 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
28358 specified log level or higher are logged.
28360 Defaults to @samp{("/var/log/nslcd" info)}.
28364 @deftypevr {@code{nslcd-configuration} parameter} list uri
28365 The list of LDAP server URIs. Normally, only the first server will be
28366 used with the following servers as fall-back.
28368 Defaults to @samp{("ldap://localhost:389/")}.
28372 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
28373 The version of the LDAP protocol to use. The default is to use the
28374 maximum version supported by the LDAP library.
28376 Defaults to @samp{disabled}.
28380 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
28381 Specifies the distinguished name with which to bind to the directory
28382 server for lookups. The default is to bind anonymously.
28384 Defaults to @samp{disabled}.
28388 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
28389 Specifies the credentials with which to bind. This option is only
28390 applicable when used with binddn.
28392 Defaults to @samp{disabled}.
28396 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
28397 Specifies the distinguished name to use when the root user tries to
28398 modify a user's password using the PAM module.
28400 Defaults to @samp{disabled}.
28404 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
28405 Specifies the credentials with which to bind if the root user tries to
28406 change a user's password. This option is only applicable when used with
28409 Defaults to @samp{disabled}.
28413 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
28414 Specifies the SASL mechanism to be used when performing SASL
28417 Defaults to @samp{disabled}.
28421 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
28422 Specifies the SASL realm to be used when performing SASL authentication.
28424 Defaults to @samp{disabled}.
28428 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
28429 Specifies the authentication identity to be used when performing SASL
28432 Defaults to @samp{disabled}.
28436 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
28437 Specifies the authorization identity to be used when performing SASL
28440 Defaults to @samp{disabled}.
28444 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
28445 Determines whether the LDAP server host name should be canonicalised. If
28446 this is enabled the LDAP library will do a reverse host name lookup. By
28447 default, it is left up to the LDAP library whether this check is
28450 Defaults to @samp{disabled}.
28454 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
28455 Set the name for the GSS-API Kerberos credentials cache.
28457 Defaults to @samp{disabled}.
28461 @deftypevr {@code{nslcd-configuration} parameter} string base
28462 The directory search base.
28464 Defaults to @samp{"dc=example,dc=com"}.
28468 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
28469 Specifies the search scope (subtree, onelevel, base or children). The
28470 default scope is subtree; base scope is almost never useful for name
28471 service lookups; children scope is not supported on all servers.
28473 Defaults to @samp{(subtree)}.
28477 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
28478 Specifies the policy for dereferencing aliases. The default policy is
28479 to never dereference aliases.
28481 Defaults to @samp{disabled}.
28485 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
28486 Specifies whether automatic referral chasing should be enabled. The
28487 default behaviour is to chase referrals.
28489 Defaults to @samp{disabled}.
28493 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
28494 This option allows for custom attributes to be looked up instead of the
28495 default RFC 2307 attributes. It is a list of maps, each consisting of
28496 the name of a map, the RFC 2307 attribute to match and the query
28497 expression for the attribute as it is available in the directory.
28499 Defaults to @samp{()}.
28503 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
28504 A list of filters consisting of the name of a map to which the filter
28505 applies and an LDAP search filter expression.
28507 Defaults to @samp{()}.
28511 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
28512 Specifies the time limit in seconds to use when connecting to the
28513 directory server. The default value is 10 seconds.
28515 Defaults to @samp{disabled}.
28519 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
28520 Specifies the time limit (in seconds) to wait for a response from the
28521 LDAP server. A value of zero, which is the default, is to wait
28522 indefinitely for searches to be completed.
28524 Defaults to @samp{disabled}.
28528 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
28529 Specifies the period if inactivity (in seconds) after which the con‐
28530 nection to the LDAP server will be closed. The default is not to time
28533 Defaults to @samp{disabled}.
28537 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
28538 Specifies the number of seconds to sleep when connecting to all LDAP
28539 servers fails. By default one second is waited between the first
28540 failure and the first retry.
28542 Defaults to @samp{disabled}.
28546 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
28547 Specifies the time after which the LDAP server is considered to be
28548 permanently unavailable. Once this time is reached retries will be done
28549 only once per this time period. The default value is 10 seconds.
28551 Defaults to @samp{disabled}.
28555 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
28556 Specifies whether to use SSL/TLS or not (the default is not to). If
28557 'start-tls is specified then StartTLS is used rather than raw LDAP over
28560 Defaults to @samp{disabled}.
28564 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
28565 Specifies what checks to perform on a server-supplied certificate. The
28566 meaning of the values is described in the ldap.conf(5) manual page.
28568 Defaults to @samp{disabled}.
28572 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
28573 Specifies the directory containing X.509 certificates for peer authen‐
28574 tication. This parameter is ignored when using GnuTLS.
28576 Defaults to @samp{disabled}.
28580 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
28581 Specifies the path to the X.509 certificate for peer authentication.
28583 Defaults to @samp{disabled}.
28587 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
28588 Specifies the path to an entropy source. This parameter is ignored when
28591 Defaults to @samp{disabled}.
28595 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
28596 Specifies the ciphers to use for TLS as a string.
28598 Defaults to @samp{disabled}.
28602 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
28603 Specifies the path to the file containing the local certificate for
28604 client TLS authentication.
28606 Defaults to @samp{disabled}.
28610 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
28611 Specifies the path to the file containing the private key for client TLS
28614 Defaults to @samp{disabled}.
28618 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
28619 Set this to a number greater than 0 to request paged results from the
28620 LDAP server in accordance with RFC2696. The default (0) is to not
28621 request paged results.
28623 Defaults to @samp{disabled}.
28627 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
28628 This option prevents group membership lookups through LDAP for the
28629 specified users. Alternatively, the value 'all-local may be used. With
28630 that value nslcd builds a full list of non-LDAP users on startup.
28632 Defaults to @samp{disabled}.
28636 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
28637 This option ensures that LDAP users with a numeric user id lower than
28638 the specified value are ignored.
28640 Defaults to @samp{disabled}.
28644 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
28645 This option specifies an offset that is added to all LDAP numeric user
28646 ids. This can be used to avoid user id collisions with local users.
28648 Defaults to @samp{disabled}.
28652 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
28653 This option specifies an offset that is added to all LDAP numeric group
28654 ids. This can be used to avoid user id collisions with local groups.
28656 Defaults to @samp{disabled}.
28660 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
28661 If this option is set, the member attribute of a group may point to
28662 another group. Members of nested groups are also returned in the higher
28663 level group and parent groups are returned when finding groups for a
28664 specific user. The default is not to perform extra searches for nested
28667 Defaults to @samp{disabled}.
28671 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
28672 If this option is set, the group member list is not retrieved when
28673 looking up groups. Lookups for finding which groups a user belongs to
28674 will remain functional so the user will likely still get the correct
28675 groups assigned on login.
28677 Defaults to @samp{disabled}.
28681 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
28682 If this option is set, functions which cause all user/group entries to
28683 be loaded from the directory will not succeed in doing so. This can
28684 dramatically reduce LDAP server load in situations where there are a
28685 great number of users and/or groups. This option is not recommended for
28686 most configurations.
28688 Defaults to @samp{disabled}.
28692 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
28693 This option can be used to specify how user and group names are verified
28694 within the system. This pattern is used to check all user and group
28695 names that are requested and returned from LDAP.
28697 Defaults to @samp{disabled}.
28701 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
28702 This specifies whether or not to perform searches using case-insensitive
28703 matching. Enabling this could open up the system to authorization
28704 bypass vulnerabilities and introduce nscd cache poisoning
28705 vulnerabilities which allow denial of service.
28707 Defaults to @samp{disabled}.
28711 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
28712 This option specifies whether password policy controls are requested and
28713 handled from the LDAP server when performing user authentication.
28715 Defaults to @samp{disabled}.
28719 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
28720 By default nslcd performs an LDAP search with the user's credentials
28721 after BIND (authentication) to ensure that the BIND operation was
28722 successful. The default search is a simple check to see if the user's
28723 DN exists. A search filter can be specified that will be used instead.
28724 It should return at least one entry.
28726 Defaults to @samp{disabled}.
28730 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
28731 This option allows flexible fine tuning of the authorisation check that
28732 should be performed. The search filter specified is executed and if any
28733 entries match, access is granted, otherwise access is denied.
28735 Defaults to @samp{disabled}.
28739 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
28740 If this option is set password modification using pam_ldap will be
28741 denied and the specified message will be presented to the user instead.
28742 The message can be used to direct the user to an alternative means of
28743 changing their password.
28745 Defaults to @samp{disabled}.
28749 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
28750 List of pam service names for which LDAP authentication should suffice.
28752 Defaults to @samp{()}.
28756 @c %end of generated documentation for nslcd-configuration
28760 @subsection Web Services
28765 The @code{(gnu services web)} module provides the Apache HTTP Server,
28766 the nginx web server, and also a fastcgi wrapper daemon.
28768 @subsubheading Apache HTTP Server
28770 @deffn {Scheme Variable} httpd-service-type
28771 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
28772 (@dfn{httpd}). The value for this service type is a
28773 @code{httpd-configuration} record.
28775 A simple example configuration is given below.
28778 (service httpd-service-type
28779 (httpd-configuration
28782 (server-name "www.example.com")
28783 (document-root "/srv/http/www.example.com")))))
28786 Other services can also extend the @code{httpd-service-type} to add to
28790 (simple-service 'www.example.com-server httpd-service-type
28794 (list (string-join '("ServerName www.example.com"
28795 "DocumentRoot /srv/http/www.example.com")
28800 The details for the @code{httpd-configuration}, @code{httpd-module},
28801 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
28804 @deffn {Data Type} httpd-configuration
28805 This data type represents the configuration for the httpd service.
28808 @item @code{package} (default: @code{httpd})
28809 The httpd package to use.
28811 @item @code{pid-file} (default: @code{"/var/run/httpd"})
28812 The pid file used by the shepherd-service.
28814 @item @code{config} (default: @code{(httpd-config-file)})
28815 The configuration file to use with the httpd service. The default value
28816 is a @code{httpd-config-file} record, but this can also be a different
28817 G-expression that generates a file, for example a @code{plain-file}. A
28818 file outside of the store can also be specified through a string.
28823 @deffn {Data Type} httpd-module
28824 This data type represents a module for the httpd service.
28828 The name of the module.
28831 The file for the module. This can be relative to the httpd package being
28832 used, the absolute location of a file, or a G-expression for a file
28833 within the store, for example @code{(file-append mod-wsgi
28834 "/modules/mod_wsgi.so")}.
28839 @defvr {Scheme Variable} %default-httpd-modules
28840 A default list of @code{httpd-module} objects.
28843 @deffn {Data Type} httpd-config-file
28844 This data type represents a configuration file for the httpd service.
28847 @item @code{modules} (default: @code{%default-httpd-modules})
28848 The modules to load. Additional modules can be added here, or loaded by
28849 additional configuration.
28851 For example, in order to handle requests for PHP files, you can use Apache’s
28852 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
28855 (service httpd-service-type
28856 (httpd-configuration
28861 (name "proxy_module")
28862 (file "modules/mod_proxy.so"))
28864 (name "proxy_fcgi_module")
28865 (file "modules/mod_proxy_fcgi.so"))
28866 %default-httpd-modules))
28867 (extra-config (list "\
28868 <FilesMatch \\.php$>
28869 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
28870 </FilesMatch>"))))))
28871 (service php-fpm-service-type
28872 (php-fpm-configuration
28873 (socket "/var/run/php-fpm.sock")
28874 (socket-group "httpd")))
28877 @item @code{server-root} (default: @code{httpd})
28878 The @code{ServerRoot} in the configuration file, defaults to the httpd
28879 package. Directives including @code{Include} and @code{LoadModule} are
28880 taken as relative to the server root.
28882 @item @code{server-name} (default: @code{#f})
28883 The @code{ServerName} in the configuration file, used to specify the
28884 request scheme, hostname and port that the server uses to identify
28887 This doesn't need to be set in the server config, and can be specified
28888 in virtual hosts. The default is @code{#f} to not specify a
28891 @item @code{document-root} (default: @code{"/srv/http"})
28892 The @code{DocumentRoot} from which files will be served.
28894 @item @code{listen} (default: @code{'("80")})
28895 The list of values for the @code{Listen} directives in the config
28896 file. The value should be a list of strings, when each string can
28897 specify the port number to listen on, and optionally the IP address and
28900 @item @code{pid-file} (default: @code{"/var/run/httpd"})
28901 The @code{PidFile} to use. This should match the @code{pid-file} set in
28902 the @code{httpd-configuration} so that the Shepherd service is
28903 configured correctly.
28905 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
28906 The @code{ErrorLog} to which the server will log errors.
28908 @item @code{user} (default: @code{"httpd"})
28909 The @code{User} which the server will answer requests as.
28911 @item @code{group} (default: @code{"httpd"})
28912 The @code{Group} which the server will answer requests as.
28914 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
28915 A flat list of strings and G-expressions which will be added to the end
28916 of the configuration file.
28918 Any values which the service is extended with will be appended to this
28924 @deffn {Data Type} httpd-virtualhost
28925 This data type represents a virtualhost configuration block for the httpd service.
28927 These should be added to the extra-config for the httpd-service.
28930 (simple-service 'www.example.com-server httpd-service-type
28934 (list (string-join '("ServerName www.example.com"
28935 "DocumentRoot /srv/http/www.example.com")
28940 @item @code{addresses-and-ports}
28941 The addresses and ports for the @code{VirtualHost} directive.
28943 @item @code{contents}
28944 The contents of the @code{VirtualHost} directive, this should be a list
28945 of strings and G-expressions.
28951 @subsubheading NGINX
28953 @deffn {Scheme Variable} nginx-service-type
28954 Service type for the @uref{https://nginx.org/,NGinx} web server. The
28955 value for this service type is a @code{<nginx-configuration>} record.
28957 A simple example configuration is given below.
28960 (service nginx-service-type
28961 (nginx-configuration
28963 (list (nginx-server-configuration
28964 (server-name '("www.example.com"))
28965 (root "/srv/http/www.example.com"))))))
28968 In addition to adding server blocks to the service configuration
28969 directly, this service can be extended by other services to add server
28970 blocks, as in this example:
28973 (simple-service 'my-extra-server nginx-service-type
28974 (list (nginx-server-configuration
28975 (root "/srv/http/extra-website")
28976 (try-files (list "$uri" "$uri/index.html")))))
28980 At startup, @command{nginx} has not yet read its configuration file, so
28981 it uses a default file to log error messages. If it fails to load its
28982 configuration file, that is where error messages are logged. After the
28983 configuration file is loaded, the default error log file changes as per
28984 configuration. In our case, startup error messages can be found in
28985 @file{/var/run/nginx/logs/error.log}, and after configuration in
28986 @file{/var/log/nginx/error.log}. The second location can be changed
28987 with the @var{log-directory} configuration option.
28989 @deffn {Data Type} nginx-configuration
28990 This data type represents the configuration for NGinx. Some
28991 configuration can be done through this and the other provided record
28992 types, or alternatively, a config file can be provided.
28995 @item @code{nginx} (default: @code{nginx})
28996 The nginx package to use.
28998 @item @code{shepherd-requirement} (default: @code{'()})
28999 This is a list of symbols naming Shepherd services the nginx service
29002 This is useful if you would like @command{nginx} to be started after a
29003 back-end web server or a logging service such as Anonip has been
29006 @item @code{log-directory} (default: @code{"/var/log/nginx"})
29007 The directory to which NGinx will write log files.
29009 @item @code{run-directory} (default: @code{"/var/run/nginx"})
29010 The directory in which NGinx will create a pid file, and write temporary
29013 @item @code{server-blocks} (default: @code{'()})
29014 A list of @dfn{server blocks} to create in the generated configuration
29015 file, the elements should be of type
29016 @code{<nginx-server-configuration>}.
29018 The following example would setup NGinx to serve @code{www.example.com}
29019 from the @code{/srv/http/www.example.com} directory, without using
29022 (service nginx-service-type
29023 (nginx-configuration
29025 (list (nginx-server-configuration
29026 (server-name '("www.example.com"))
29027 (root "/srv/http/www.example.com"))))))
29030 @item @code{upstream-blocks} (default: @code{'()})
29031 A list of @dfn{upstream blocks} to create in the generated configuration
29032 file, the elements should be of type
29033 @code{<nginx-upstream-configuration>}.
29035 Configuring upstreams through the @code{upstream-blocks} can be useful
29036 when combined with @code{locations} in the
29037 @code{<nginx-server-configuration>} records. The following example
29038 creates a server configuration with one location configuration, that
29039 will proxy requests to a upstream configuration, which will handle
29040 requests with two servers.
29045 (nginx-configuration
29047 (list (nginx-server-configuration
29048 (server-name '("www.example.com"))
29049 (root "/srv/http/www.example.com")
29052 (nginx-location-configuration
29054 (body '("proxy_pass http://server-proxy;"))))))))
29056 (list (nginx-upstream-configuration
29057 (name "server-proxy")
29058 (servers (list "server1.example.com"
29059 "server2.example.com")))))))
29062 @item @code{file} (default: @code{#f})
29063 If a configuration @var{file} is provided, this will be used, rather than
29064 generating a configuration file from the provided @code{log-directory},
29065 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
29066 proper operation, these arguments should match what is in @var{file} to ensure
29067 that the directories are created when the service is activated.
29069 This can be useful if you have an existing configuration file, or it's
29070 not possible to do what is required through the other parts of the
29071 nginx-configuration record.
29073 @item @code{server-names-hash-bucket-size} (default: @code{#f})
29074 Bucket size for the server names hash tables, defaults to @code{#f} to
29075 use the size of the processors cache line.
29077 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
29078 Maximum bucket size for the server names hash tables.
29080 @item @code{modules} (default: @code{'()})
29081 List of nginx dynamic modules to load. This should be a list of file
29082 names of loadable modules, as in this example:
29087 (file-append nginx-accept-language-module "\
29088 /etc/nginx/modules/ngx_http_accept_language_module.so")
29089 (file-append nginx-lua-module "\
29090 /etc/nginx/modules/ngx_http_lua_module.so")))
29093 @item @code{lua-package-path} (default: @code{'()})
29094 List of nginx lua packages to load. This should be a list of package
29095 names of loadable lua modules, as in this example:
29098 (lua-package-path (list lua-resty-core
29105 @item @code{lua-package-cpath} (default: @code{'()})
29106 List of nginx lua C packages to load. This should be a list of package
29107 names of loadable lua C modules, as in this example:
29110 (lua-package-cpath (list lua-resty-signal))
29113 @item @code{global-directives} (default: @code{'((events . ()))})
29114 Association list of global directives for the top level of the nginx
29115 configuration. Values may themselves be association lists.
29119 `((worker_processes . 16)
29121 (events . ((worker_connections . 1024)))))
29124 @item @code{extra-content} (default: @code{""})
29125 Extra content for the @code{http} block. Should be string or a string
29126 valued G-expression.
29131 @anchor{nginx-server-configuration}
29132 @deftp {Data Type} nginx-server-configuration
29133 Data type representing the configuration of an nginx server block.
29134 This type has the following parameters:
29137 @item @code{listen} (default: @code{'("80" "443 ssl")})
29138 Each @code{listen} directive sets the address and port for IP, or the
29139 path for a UNIX-domain socket on which the server will accept requests.
29140 Both address and port, or only address or only port can be specified.
29141 An address may also be a hostname, for example:
29144 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
29147 @item @code{server-name} (default: @code{(list 'default)})
29148 A list of server names this server represents. @code{'default} represents the
29149 default server for connections matching no other server.
29151 @item @code{root} (default: @code{"/srv/http"})
29152 Root of the website nginx will serve.
29154 @item @code{locations} (default: @code{'()})
29155 A list of @dfn{nginx-location-configuration} or
29156 @dfn{nginx-named-location-configuration} records to use within this
29159 @item @code{index} (default: @code{(list "index.html")})
29160 Index files to look for when clients ask for a directory. If it cannot be found,
29161 Nginx will send the list of files in the directory.
29163 @item @code{try-files} (default: @code{'()})
29164 A list of files whose existence is checked in the specified order.
29165 @code{nginx} will use the first file it finds to process the request.
29167 @item @code{ssl-certificate} (default: @code{#f})
29168 Where to find the certificate for secure connections. Set it to @code{#f} if
29169 you don't have a certificate or you don't want to use HTTPS.
29171 @item @code{ssl-certificate-key} (default: @code{#f})
29172 Where to find the private key for secure connections. Set it to @code{#f} if
29173 you don't have a key or you don't want to use HTTPS.
29175 @item @code{server-tokens?} (default: @code{#f})
29176 Whether the server should add its configuration to response.
29178 @item @code{raw-content} (default: @code{'()})
29179 A list of raw lines added to the server block.
29184 @deftp {Data Type} nginx-upstream-configuration
29185 Data type representing the configuration of an nginx @code{upstream}
29186 block. This type has the following parameters:
29190 Name for this group of servers.
29192 @item @code{servers}
29193 Specify the addresses of the servers in the group. The address can be
29194 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
29195 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
29196 prefix @samp{unix:}. For addresses using an IP address or domain name,
29197 the default port is 80, and a different port can be specified
29200 @item @code{extra-content}
29201 A string or list of strings to add to the upstream block.
29206 @deftp {Data Type} nginx-location-configuration
29207 Data type representing the configuration of an nginx @code{location}
29208 block. This type has the following parameters:
29212 URI which this location block matches.
29214 @anchor{nginx-location-configuration body}
29216 Body of the location block, specified as a list of strings. This can contain
29218 configuration directives. For example, to pass requests to a upstream
29219 server group defined using an @code{nginx-upstream-configuration} block,
29220 the following directive would be specified in the body @samp{(list "proxy_pass
29221 http://upstream-name;")}.
29226 @deftp {Data Type} nginx-named-location-configuration
29227 Data type representing the configuration of an nginx named location
29228 block. Named location blocks are used for request redirection, and not
29229 used for regular request processing. This type has the following
29234 Name to identify this location block.
29237 @xref{nginx-location-configuration body}, as the body for named location
29238 blocks can be used in a similar way to the
29239 @code{nginx-location-configuration body}. One restriction is that the
29240 body of a named location block cannot contain location blocks.
29245 @subsubheading Varnish Cache
29247 Varnish is a fast cache server that sits in between web applications
29248 and end users. It proxies requests from clients and caches the
29249 accessed URLs such that multiple requests for the same resource only
29250 creates one request to the back-end.
29252 @defvr {Scheme Variable} varnish-service-type
29253 Service type for the Varnish daemon.
29256 @deftp {Data Type} varnish-configuration
29257 Data type representing the @code{varnish} service configuration.
29258 This type has the following parameters:
29261 @item @code{package} (default: @code{varnish})
29262 The Varnish package to use.
29264 @item @code{name} (default: @code{"default"})
29265 A name for this Varnish instance. Varnish will create a directory in
29266 @file{/var/varnish/} with this name and keep temporary files there. If
29267 the name starts with a forward slash, it is interpreted as an absolute
29270 Pass the @code{-n} argument to other Varnish programs to connect to the
29271 named instance, e.g.@: @command{varnishncsa -n default}.
29273 @item @code{backend} (default: @code{"localhost:8080"})
29274 The backend to use. This option has no effect if @code{vcl} is set.
29276 @item @code{vcl} (default: #f)
29277 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
29278 is @code{#f}, Varnish will proxy @code{backend} using the default
29279 configuration. Otherwise this must be a file-like object with valid
29282 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
29283 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
29284 can do something along these lines:
29287 (define %gnu-mirror
29288 (plain-file "gnu.vcl"
29290 backend gnu @{ .host = \"www.gnu.org\"; @}"))
29294 (services (cons (service varnish-service-type
29295 (varnish-configuration
29297 (vcl %gnu-mirror)))
29301 The configuration of an already running Varnish instance can be inspected
29302 and changed using the @command{varnishadm} program.
29304 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
29305 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
29306 comprehensive documentation on Varnish and its configuration language.
29308 @item @code{listen} (default: @code{'("localhost:80")})
29309 List of addresses Varnish will listen on.
29311 @item @code{storage} (default: @code{'("malloc,128m")})
29312 List of storage backends that will be available in VCL.
29314 @item @code{parameters} (default: @code{'()})
29315 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
29317 @item @code{extra-options} (default: @code{'()})
29318 Additional arguments to pass to the @command{varnishd} process.
29323 @subsubheading Patchwork
29325 Patchwork is a patch tracking system. It can collect patches sent to a
29326 mailing list, and display them in a web interface.
29328 @defvr {Scheme Variable} patchwork-service-type
29329 Service type for Patchwork.
29332 The following example is an example of a minimal service for Patchwork, for
29333 the @code{patchwork.example.com} domain.
29336 (service patchwork-service-type
29337 (patchwork-configuration
29338 (domain "patchwork.example.com")
29340 (patchwork-settings-module
29341 (allowed-hosts (list domain))
29342 (default-from-email "patchwork@@patchwork.example.com")))
29343 (getmail-retriever-config
29344 (getmail-retriever-configuration
29345 (type "SimpleIMAPSSLRetriever")
29346 (server "imap.example.com")
29348 (username "patchwork")
29350 (list (file-append coreutils "/bin/cat")
29351 "/etc/getmail-patchwork-imap-password"))
29353 '((mailboxes . ("Patches"))))))))
29357 There are three records for configuring the Patchwork service. The
29358 @code{<patchwork-configuration>} relates to the configuration for Patchwork
29359 within the HTTPD service.
29361 The @code{settings-module} field within the @code{<patchwork-configuration>}
29362 record can be populated with the @code{<patchwork-settings-module>} record,
29363 which describes a settings module that is generated within the Guix store.
29365 For the @code{database-configuration} field within the
29366 @code{<patchwork-settings-module>}, the
29367 @code{<patchwork-database-configuration>} must be used.
29369 @deftp {Data Type} patchwork-configuration
29370 Data type representing the Patchwork service configuration. This type has the
29371 following parameters:
29374 @item @code{patchwork} (default: @code{patchwork})
29375 The Patchwork package to use.
29377 @item @code{domain}
29378 The domain to use for Patchwork, this is used in the HTTPD service virtual
29381 @item @code{settings-module}
29382 The settings module to use for Patchwork. As a Django application, Patchwork
29383 is configured with a Python module containing the settings. This can either be
29384 an instance of the @code{<patchwork-settings-module>} record, any other record
29385 that represents the settings in the store, or a directory outside of the
29388 @item @code{static-path} (default: @code{"/static/"})
29389 The path under which the HTTPD service should serve the static files.
29391 @item @code{getmail-retriever-config}
29392 The getmail-retriever-configuration record value to use with
29393 Patchwork. Getmail will be configured with this value, the messages will be
29394 delivered to Patchwork.
29399 @deftp {Data Type} patchwork-settings-module
29400 Data type representing a settings module for Patchwork. Some of these
29401 settings relate directly to Patchwork, but others relate to Django, the web
29402 framework used by Patchwork, or the Django Rest Framework library. This type
29403 has the following parameters:
29406 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
29407 The database connection settings used for Patchwork. See the
29408 @code{<patchwork-database-configuration>} record type for more information.
29410 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
29411 Patchwork, as a Django web application uses a secret key for cryptographically
29412 signing values. This file should contain a unique unpredictable value.
29414 If this file does not exist, it will be created and populated with a random
29415 value by the patchwork-setup shepherd service.
29417 This setting relates to Django.
29419 @item @code{allowed-hosts}
29420 A list of valid hosts for this Patchwork service. This should at least include
29421 the domain specified in the @code{<patchwork-configuration>} record.
29423 This is a Django setting.
29425 @item @code{default-from-email}
29426 The email address from which Patchwork should send email by default.
29428 This is a Patchwork setting.
29430 @item @code{static-url} (default: @code{#f})
29431 The URL to use when serving static assets. It can be part of a URL, or a full
29432 URL, but must end in a @code{/}.
29434 If the default value is used, the @code{static-path} value from the
29435 @code{<patchwork-configuration>} record will be used.
29437 This is a Django setting.
29439 @item @code{admins} (default: @code{'()})
29440 Email addresses to send the details of errors that occur. Each value should
29441 be a list containing two elements, the name and then the email address.
29443 This is a Django setting.
29445 @item @code{debug?} (default: @code{#f})
29446 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
29447 messages will be shown.
29449 This is a Django setting.
29451 @item @code{enable-rest-api?} (default: @code{#t})
29452 Whether to enable the Patchwork REST API.
29454 This is a Patchwork setting.
29456 @item @code{enable-xmlrpc?} (default: @code{#t})
29457 Whether to enable the XML RPC API.
29459 This is a Patchwork setting.
29461 @item @code{force-https-links?} (default: @code{#t})
29462 Whether to use HTTPS links on Patchwork pages.
29464 This is a Patchwork setting.
29466 @item @code{extra-settings} (default: @code{""})
29467 Extra code to place at the end of the Patchwork settings module.
29472 @deftp {Data Type} patchwork-database-configuration
29473 Data type representing the database configuration for Patchwork.
29476 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
29477 The database engine to use.
29479 @item @code{name} (default: @code{"patchwork"})
29480 The name of the database to use.
29482 @item @code{user} (default: @code{"httpd"})
29483 The user to connect to the database as.
29485 @item @code{password} (default: @code{""})
29486 The password to use when connecting to the database.
29488 @item @code{host} (default: @code{""})
29489 The host to make the database connection to.
29491 @item @code{port} (default: @code{""})
29492 The port on which to connect to the database.
29497 @subsubheading Mumi
29499 @cindex Mumi, Debbugs Web interface
29500 @cindex Debbugs, Mumi Web interface
29501 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
29502 Web interface to the Debbugs bug tracker, by default for
29503 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
29504 but it also fetches and indexes mail retrieved from Debbugs.
29506 @defvr {Scheme Variable} mumi-service-type
29507 This is the service type for Mumi.
29510 @deftp {Data Type} mumi-configuration
29511 Data type representing the Mumi service configuration. This type has the
29515 @item @code{mumi} (default: @code{mumi})
29516 The Mumi package to use.
29518 @item @code{mailer?} (default: @code{#true})
29519 Whether to enable or disable the mailer component.
29521 @item @code{mumi-configuration-sender}
29522 The email address used as the sender for comments.
29524 @item @code{mumi-configuration-smtp}
29525 A URI to configure the SMTP settings for Mailutils. This could be
29526 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
29527 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
29528 mailutils, GNU@tie{}Mailutils}.
29534 @subsubheading FastCGI
29537 FastCGI is an interface between the front-end and the back-end of a web
29538 service. It is a somewhat legacy facility; new web services should
29539 generally just talk HTTP between the front-end and the back-end.
29540 However there are a number of back-end services such as PHP or the
29541 optimized HTTP Git repository access that use FastCGI, so we have
29542 support for it in Guix.
29544 To use FastCGI, you configure the front-end web server (e.g., nginx) to
29545 dispatch some subset of its requests to the fastcgi backend, which
29546 listens on a local TCP or UNIX socket. There is an intermediary
29547 @code{fcgiwrap} program that sits between the actual backend process and
29548 the web server. The front-end indicates which backend program to run,
29549 passing that information to the @code{fcgiwrap} process.
29551 @defvr {Scheme Variable} fcgiwrap-service-type
29552 A service type for the @code{fcgiwrap} FastCGI proxy.
29555 @deftp {Data Type} fcgiwrap-configuration
29556 Data type representing the configuration of the @code{fcgiwrap} service.
29557 This type has the following parameters:
29559 @item @code{package} (default: @code{fcgiwrap})
29560 The fcgiwrap package to use.
29562 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
29563 The socket on which the @code{fcgiwrap} process should listen, as a
29564 string. Valid @var{socket} values include
29565 @code{unix:@var{/path/to/unix/socket}},
29566 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
29567 @code{tcp6:[@var{ipv6_addr}]:port}.
29569 @item @code{user} (default: @code{fcgiwrap})
29570 @itemx @code{group} (default: @code{fcgiwrap})
29571 The user and group names, as strings, under which to run the
29572 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
29573 the user asks for the specific user or group names @code{fcgiwrap} that
29574 the corresponding user and/or group is present on the system.
29576 It is possible to configure a FastCGI-backed web service to pass HTTP
29577 authentication information from the front-end to the back-end, and to
29578 allow @code{fcgiwrap} to run the back-end process as a corresponding
29579 local user. To enable this capability on the back-end, run
29580 @code{fcgiwrap} as the @code{root} user and group. Note that this
29581 capability also has to be configured on the front-end as well.
29586 @subsubheading PHP-FPM
29588 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
29589 with some additional features useful for sites of any size.
29591 These features include:
29593 @item Adaptive process spawning
29594 @item Basic statistics (similar to Apache's mod_status)
29595 @item Advanced process management with graceful stop/start
29596 @item Ability to start workers with different uid/gid/chroot/environment
29597 and different php.ini (replaces safe_mode)
29598 @item Stdout & stderr logging
29599 @item Emergency restart in case of accidental opcode cache destruction
29600 @item Accelerated upload support
29601 @item Support for a "slowlog"
29602 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
29603 a special function to finish request & flush all data while continuing to do
29604 something time-consuming (video converting, stats processing, etc.)
29606 ...@: and much more.
29608 @defvr {Scheme Variable} php-fpm-service-type
29609 A Service type for @code{php-fpm}.
29612 @deftp {Data Type} php-fpm-configuration
29613 Data Type for php-fpm service configuration.
29615 @item @code{php} (default: @code{php})
29616 The php package to use.
29617 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
29618 The address on which to accept FastCGI requests. Valid syntaxes are:
29620 @item @code{"ip.add.re.ss:port"}
29621 Listen on a TCP socket to a specific address on a specific port.
29622 @item @code{"port"}
29623 Listen on a TCP socket to all addresses on a specific port.
29624 @item @code{"/path/to/unix/socket"}
29625 Listen on a unix socket.
29628 @item @code{user} (default: @code{php-fpm})
29629 User who will own the php worker processes.
29630 @item @code{group} (default: @code{php-fpm})
29631 Group of the worker processes.
29632 @item @code{socket-user} (default: @code{php-fpm})
29633 User who can speak to the php-fpm socket.
29634 @item @code{socket-group} (default: @code{nginx})
29635 Group that can speak to the php-fpm socket.
29636 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
29637 The process id of the php-fpm process is written to this file
29638 once the service has started.
29639 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
29640 Log for the php-fpm master process.
29641 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
29642 Detailed settings for the php-fpm process manager.
29645 @item @code{<php-fpm-dynamic-process-manager-configuration>}
29646 @item @code{<php-fpm-static-process-manager-configuration>}
29647 @item @code{<php-fpm-on-demand-process-manager-configuration>}
29649 @item @code{display-errors} (default @code{#f})
29650 Determines whether php errors and warning should be sent to clients
29651 and displayed in their browsers.
29652 This is useful for local php development, but a security risk for public sites,
29653 as error messages can reveal passwords and personal data.
29654 @item @code{timezone} (default @code{#f})
29655 Specifies @code{php_admin_value[date.timezone]} parameter.
29656 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
29657 This file will log the @code{stderr} outputs of php worker processes.
29658 Can be set to @code{#f} to disable logging.
29659 @item @code{file} (default @code{#f})
29660 An optional override of the whole configuration.
29661 You can use the @code{mixed-text-file} function or an absolute filepath for it.
29662 @item @code{php-ini-file} (default @code{#f})
29663 An optional override of the default php settings.
29664 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
29665 You can use the @code{mixed-text-file} function or an absolute filepath for it.
29667 For local development it is useful to set a higher timeout and memory
29668 limit for spawned php processes. This be accomplished with the
29669 following operating system configuration snippet:
29671 (define %local-php-ini
29672 (plain-file "php.ini"
29674 max_execution_time = 1800"))
29678 (services (cons (service php-fpm-service-type
29679 (php-fpm-configuration
29680 (php-ini-file %local-php-ini)))
29684 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
29685 directives} for comprehensive documentation on the acceptable
29686 @file{php.ini} directives.
29690 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
29691 Data Type for the @code{dynamic} php-fpm process manager. With the
29692 @code{dynamic} process manager, spare worker processes are kept around
29693 based on its configured limits.
29695 @item @code{max-children} (default: @code{5})
29696 Maximum of worker processes.
29697 @item @code{start-servers} (default: @code{2})
29698 How many worker processes should be started on start-up.
29699 @item @code{min-spare-servers} (default: @code{1})
29700 How many spare worker processes should be kept around at minimum.
29701 @item @code{max-spare-servers} (default: @code{3})
29702 How many spare worker processes should be kept around at maximum.
29706 @deftp {Data type} php-fpm-static-process-manager-configuration
29707 Data Type for the @code{static} php-fpm process manager. With the
29708 @code{static} process manager, an unchanging number of worker processes
29711 @item @code{max-children} (default: @code{5})
29712 Maximum of worker processes.
29716 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
29717 Data Type for the @code{on-demand} php-fpm process manager. With the
29718 @code{on-demand} process manager, worker processes are only created as
29721 @item @code{max-children} (default: @code{5})
29722 Maximum of worker processes.
29723 @item @code{process-idle-timeout} (default: @code{10})
29724 The time in seconds after which a process with no requests is killed.
29729 @deffn {Scheme Procedure} nginx-php-location @
29730 [#:nginx-package nginx] @
29731 [socket (string-append "/var/run/php" @
29732 (version-major (package-version php)) @
29734 A helper function to quickly add php to an @code{nginx-server-configuration}.
29737 A simple services setup for nginx with php can look like this:
29739 (services (cons* (service dhcp-client-service-type)
29740 (service php-fpm-service-type)
29741 (service nginx-service-type
29742 (nginx-server-configuration
29743 (server-name '("example.com"))
29744 (root "/srv/http/")
29746 (list (nginx-php-location)))
29748 (ssl-certificate #f)
29749 (ssl-certificate-key #f)))
29753 @cindex cat-avatar-generator
29754 The cat avatar generator is a simple service to demonstrate the use of php-fpm
29755 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
29756 the hash of a user's email address.
29758 @deffn {Scheme Procedure} cat-avatar-generator-service @
29759 [#:cache-dir "/var/cache/cat-avatar-generator"] @
29760 [#:package cat-avatar-generator] @
29761 [#:configuration (nginx-server-configuration)]
29762 Returns an nginx-server-configuration that inherits @code{configuration}. It
29763 extends the nginx configuration to add a server block that serves @code{package},
29764 a version of cat-avatar-generator. During execution, cat-avatar-generator will
29765 be able to use @code{cache-dir} as its cache directory.
29768 A simple setup for cat-avatar-generator can look like this:
29770 (services (cons* (cat-avatar-generator-service
29772 (nginx-server-configuration
29773 (server-name '("example.com"))))
29778 @subsubheading Hpcguix-web
29780 @cindex hpcguix-web
29781 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
29782 program is a customizable web interface to browse Guix packages,
29783 initially designed for users of high-performance computing (HPC)
29786 @defvr {Scheme Variable} hpcguix-web-service-type
29787 The service type for @code{hpcguix-web}.
29790 @deftp {Data Type} hpcguix-web-configuration
29791 Data type for the hpcguix-web service configuration.
29795 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
29796 configuration. The main items available in this spec are:
29799 @item @code{title-prefix} (default: @code{"hpcguix | "})
29800 The page title prefix.
29802 @item @code{guix-command} (default: @code{"guix"})
29803 The @command{guix} command.
29805 @item @code{package-filter-proc} (default: @code{(const #t)})
29806 A procedure specifying how to filter packages that are displayed.
29808 @item @code{package-page-extension-proc} (default: @code{(const '())})
29809 Extension package for @code{hpcguix-web}.
29811 @item @code{menu} (default: @code{'()})
29812 Additional entry in page @code{menu}.
29814 @item @code{channels} (default: @code{%default-channels})
29815 List of channels from which the package list is built (@pxref{Channels}).
29817 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
29818 The expiration time, in seconds, after which the package list is rebuilt from
29819 the latest instances of the given channels.
29822 See the hpcguix-web repository for a
29823 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
29826 @item @code{package} (default: @code{hpcguix-web})
29827 The hpcguix-web package to use.
29829 @item @code{address} (default: @code{"127.0.0.1"})
29830 The IP address to listen to.
29832 @item @code{port} (default: @code{5000})
29833 The port number to listen to.
29837 A typical hpcguix-web service declaration looks like this:
29840 (service hpcguix-web-service-type
29841 (hpcguix-web-configuration
29843 #~(define site-config
29844 (hpcweb-configuration
29845 (title-prefix "Guix-HPC - ")
29846 (menu '(("/about" "ABOUT"))))))))
29850 The hpcguix-web service periodically updates the package list it publishes by
29851 pulling channels from Git. To that end, it needs to access X.509 certificates
29852 so that it can authenticate Git servers when communicating over HTTPS, and it
29853 assumes that @file{/etc/ssl/certs} contains those certificates.
29855 Thus, make sure to add @code{nss-certs} or another certificate package to the
29856 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
29857 more information on X.509 certificates.
29860 @subsubheading gmnisrv
29863 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
29864 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
29866 @deffn {Scheme Variable} gmnisrv-service-type
29867 This is the type of the gmnisrv service, whose value should be a
29868 @code{gmnisrv-configuration} object, as in this example:
29871 (service gmnisrv-service-type
29872 (gmnisrv-configuration
29873 (config-file (local-file "./my-gmnisrv.ini"))))
29877 @deftp {Data Type} gmnisrv-configuration
29878 Data type representing the configuration of gmnisrv.
29881 @item @code{package} (default: @var{gmnisrv})
29882 Package object of the gmnisrv server.
29884 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
29885 File-like object of the gmnisrv configuration file to use. The default
29886 configuration listens on port 1965 and serves files from
29887 @file{/srv/gemini}. Certificates are stored in
29888 @file{/var/lib/gemini/certs}. For more information, run @command{man
29889 gmnisrv} and @command{man gmnisrv.ini}.
29894 @subsubheading Agate
29897 The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
29898 (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
29899 program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
29900 protocol server written in Rust.
29902 @deffn {Scheme Variable} agate-service-type
29903 This is the type of the agate service, whose value should be an
29904 @code{agate-service-type} object, as in this example:
29907 (service agate-service-type
29908 (agate-configuration
29909 (content "/srv/gemini")
29910 (cert "/srv/cert.pem")
29911 (key "/srv/key.rsa")))
29914 The example above represents the minimal tweaking necessary to get Agate
29915 up and running. Specifying the path to the certificate and key is
29916 always necessary, as the Gemini protocol requires TLS by default.
29918 To obtain a certificate and a key, you could, for example, use OpenSSL,
29919 running a command similar to the following example:
29922 openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
29923 -days 3650 -nodes -subj "/CN=example.com"
29926 Of course, you'll have to replace @i{example.com} with your own domain
29927 name, and then point the Agate configuration towards the path of the
29928 generated key and certificate.
29932 @deftp {Data Type} agate-configuration
29933 Data type representing the configuration of Agate.
29936 @item @code{package} (default: @code{agate})
29937 The package object of the Agate server.
29939 @item @code{content} (default: @file{"/srv/gemini"})
29940 The directory from which Agate will serve files.
29942 @item @code{cert} (default: @code{#f})
29943 The path to the TLS certificate PEM file to be used for encrypted
29944 connections. Must be filled in with a value from the user.
29946 @item @code{key} (default: @code{#f})
29947 The path to the PKCS8 private key file to be used for encrypted
29948 connections. Must be filled in with a value from the user.
29950 @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
29951 A list of the addresses to listen on.
29953 @item @code{hostname} (default: @code{#f})
29954 The domain name of this Gemini server. Optional.
29956 @item @code{lang} (default: @code{#f})
29957 RFC 4646 language code(s) for text/gemini documents. Optional.
29959 @item @code{silent?} (default: @code{#f})
29960 Set to @code{#t} to disable logging output.
29962 @item @code{serve-secret?} (default: @code{#f})
29963 Set to @code{#t} to serve secret files (files/directories starting with
29966 @item @code{log-ip?} (default: @code{#t})
29967 Whether or not to output IP addresses when logging.
29969 @item @code{user} (default: @code{"agate"})
29970 Owner of the @code{agate} process.
29972 @item @code{group} (default: @code{"agate"})
29973 Owner's group of the @code{agate} process.
29975 @item @code{log-file} (default: @file{"/var/log/agate.log"})
29976 The file which should store the logging output of Agate.
29981 @node Certificate Services
29982 @subsection Certificate Services
29985 @cindex HTTP, HTTPS
29986 @cindex Let's Encrypt
29987 @cindex TLS certificates
29988 The @code{(gnu services certbot)} module provides a service to
29989 automatically obtain a valid TLS certificate from the Let's Encrypt
29990 certificate authority. These certificates can then be used to serve
29991 content securely over HTTPS or other TLS-based protocols, with the
29992 knowledge that the client will be able to verify the server's
29995 @url{https://letsencrypt.org/, Let's Encrypt} provides the
29996 @code{certbot} tool to automate the certification process. This tool
29997 first securely generates a key on the server. It then makes a request
29998 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
29999 checks that the request originates from the host in question by using a
30000 challenge-response protocol, requiring the server to provide its
30001 response over HTTP@. If that protocol completes successfully, the CA
30002 signs the key, resulting in a certificate. That certificate is valid
30003 for a limited period of time, and therefore to continue to provide TLS
30004 services, the server needs to periodically ask the CA to renew its
30007 The certbot service automates this process: the initial key
30008 generation, the initial certification request to the Let's Encrypt
30009 service, the web server challenge/response integration, writing the
30010 certificate to disk, the automated periodic renewals, and the deployment
30011 tasks associated with the renewal (e.g.@: reloading services, copying keys
30012 with different permissions).
30014 Certbot is run twice a day, at a random minute within the hour. It
30015 won't do anything until your certificates are due for renewal or
30016 revoked, but running it regularly would give your service a chance of
30017 staying online in case a Let's Encrypt-initiated revocation happened for
30020 By using this service, you agree to the ACME Subscriber Agreement, which
30021 can be found there:
30022 @url{https://acme-v01.api.letsencrypt.org/directory}.
30024 @defvr {Scheme Variable} certbot-service-type
30025 A service type for the @code{certbot} Let's Encrypt client. Its value
30026 must be a @code{certbot-configuration} record as in this example:
30029 (define %nginx-deploy-hook
30031 "nginx-deploy-hook"
30032 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
30033 (kill pid SIGHUP))))
30035 (service certbot-service-type
30036 (certbot-configuration
30037 (email "foo@@example.net")
30040 (certificate-configuration
30041 (domains '("example.net" "www.example.net"))
30042 (deploy-hook %nginx-deploy-hook))
30043 (certificate-configuration
30044 (domains '("bar.example.net")))))))
30047 See below for details about @code{certbot-configuration}.
30050 @deftp {Data Type} certbot-configuration
30051 Data type representing the configuration of the @code{certbot} service.
30052 This type has the following parameters:
30055 @item @code{package} (default: @code{certbot})
30056 The certbot package to use.
30058 @item @code{webroot} (default: @code{/var/www})
30059 The directory from which to serve the Let's Encrypt challenge/response
30062 @item @code{certificates} (default: @code{()})
30063 A list of @code{certificates-configuration}s for which to generate
30064 certificates and request signatures. Each certificate has a @code{name}
30065 and several @code{domains}.
30067 @item @code{email} (default: @code{#f})
30068 Optional email address used for registration and recovery contact.
30069 Setting this is encouraged as it allows you to receive important
30070 notifications about the account and issued certificates.
30072 @item @code{server} (default: @code{#f})
30073 Optional URL of ACME server. Setting this overrides certbot's default,
30074 which is the Let's Encrypt server.
30076 @item @code{rsa-key-size} (default: @code{2048})
30077 Size of the RSA key.
30079 @item @code{default-location} (default: @i{see below})
30080 The default @code{nginx-location-configuration}. Because @code{certbot}
30081 needs to be able to serve challenges and responses, it needs to be able
30082 to run a web server. It does so by extending the @code{nginx} web
30083 service with an @code{nginx-server-configuration} listening on the
30084 @var{domains} on port 80, and which has a
30085 @code{nginx-location-configuration} for the @code{/.well-known/} URI
30086 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
30087 these nginx configuration data types.
30089 Requests to other URL paths will be matched by the
30090 @code{default-location}, which if present is added to all
30091 @code{nginx-server-configuration}s.
30093 By default, the @code{default-location} will issue a redirect from
30094 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
30095 you to define what to serve on your site via @code{https}.
30097 Pass @code{#f} to not issue a default location.
30101 @deftp {Data Type} certificate-configuration
30102 Data type representing the configuration of a certificate.
30103 This type has the following parameters:
30106 @item @code{name} (default: @i{see below})
30107 This name is used by Certbot for housekeeping and in file paths; it
30108 doesn't affect the content of the certificate itself. To see
30109 certificate names, run @code{certbot certificates}.
30111 Its default is the first provided domain.
30113 @item @code{domains} (default: @code{()})
30114 The first domain provided will be the subject CN of the certificate, and
30115 all domains will be Subject Alternative Names on the certificate.
30117 @item @code{challenge} (default: @code{#f})
30118 The challenge type that has to be run by certbot. If @code{#f} is specified,
30119 default to the HTTP challenge. If a value is specified, defaults to the
30120 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
30121 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
30122 and gives Let's Encrypt permission to log the public IP address of the
30123 requesting machine.
30125 @item @code{csr} (default: @code{#f})
30126 File name of Certificate Signing Request (CSR) in DER or PEM format.
30127 If @code{#f} is specified, this argument will not be passed to certbot.
30128 If a value is specified, certbot will use it to obtain a certificate, instead of
30129 using a self-generated CSR.
30130 The domain-name(s) mentioned in @code{domains}, must be consistent with the
30131 domain-name(s) mentioned in CSR file.
30133 @item @code{authentication-hook} (default: @code{#f})
30134 Command to be run in a shell once for each certificate challenge to be
30135 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
30136 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
30137 contains the validation string and @code{$CERTBOT_TOKEN} contains the
30138 file name of the resource requested when performing an HTTP-01 challenge.
30140 @item @code{cleanup-hook} (default: @code{#f})
30141 Command to be run in a shell once for each certificate challenge that
30142 have been answered by the @code{auth-hook}. For this command, the shell
30143 variables available in the @code{auth-hook} script are still available, and
30144 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
30145 of the @code{auth-hook} script.
30147 @item @code{deploy-hook} (default: @code{#f})
30148 Command to be run in a shell once for each successfully issued
30149 certificate. For this command, the shell variable
30150 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
30151 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
30152 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
30153 contain a space-delimited list of renewed certificate domains (for
30154 example, @samp{"example.com www.example.com"}.
30159 For each @code{certificate-configuration}, the certificate is saved to
30160 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
30161 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
30163 @subsection DNS Services
30164 @cindex DNS (domain name system)
30165 @cindex domain name system (DNS)
30167 The @code{(gnu services dns)} module provides services related to the
30168 @dfn{domain name system} (DNS). It provides a server service for hosting
30169 an @emph{authoritative} DNS server for multiple zones, slave or master.
30170 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
30171 caching and forwarding DNS server for the LAN, which uses
30172 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
30174 @subsubheading Knot Service
30176 An example configuration of an authoritative server for two zones, one master
30180 (define-zone-entries example.org.zone
30181 ;; Name TTL Class Type Data
30182 ("@@" "" "IN" "A" "127.0.0.1")
30183 ("@@" "" "IN" "NS" "ns")
30184 ("ns" "" "IN" "A" "127.0.0.1"))
30186 (define master-zone
30187 (knot-zone-configuration
30188 (domain "example.org")
30190 (origin "example.org")
30191 (entries example.org.zone)))))
30194 (knot-zone-configuration
30195 (domain "plop.org")
30196 (dnssec-policy "default")
30197 (master (list "plop-master"))))
30199 (define plop-master
30200 (knot-remote-configuration
30202 (address (list "208.76.58.171"))))
30206 (services (cons* (service knot-service-type
30207 (knot-configuration
30208 (remotes (list plop-master))
30209 (zones (list master-zone slave-zone))))
30214 @deffn {Scheme Variable} knot-service-type
30215 This is the type for the Knot DNS server.
30217 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
30218 zones, that is to say domain names you would buy from a registrar. This server
30219 is not a resolver, meaning that it can only resolve names for which it is
30220 authoritative. This server can be configured to serve zones as a master server
30221 or a slave server as a per-zone basis. Slave zones will get their data from
30222 masters, and will serve it as an authoritative server. From the point of view
30223 of a resolver, there is no difference between master and slave.
30225 The following data types are used to configure the Knot DNS server:
30228 @deftp {Data Type} knot-key-configuration
30229 Data type representing a key.
30230 This type has the following parameters:
30233 @item @code{id} (default: @code{""})
30234 An identifier for other configuration fields to refer to this key. IDs must
30235 be unique and must not be empty.
30237 @item @code{algorithm} (default: @code{#f})
30238 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
30239 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
30240 and @code{'hmac-sha512}.
30242 @item @code{secret} (default: @code{""})
30243 The secret key itself.
30248 @deftp {Data Type} knot-acl-configuration
30249 Data type representing an Access Control List (ACL) configuration.
30250 This type has the following parameters:
30253 @item @code{id} (default: @code{""})
30254 An identifier for other configuration fields to refer to this key. IDs must be
30255 unique and must not be empty.
30257 @item @code{address} (default: @code{'()})
30258 An ordered list of IP addresses, network subnets, or network ranges represented
30259 with strings. The query must match one of them. Empty value means that
30260 address match is not required.
30262 @item @code{key} (default: @code{'()})
30263 An ordered list of references to keys represented with strings. The string
30264 must match a key ID defined in a @code{knot-key-configuration}. No key means
30265 that a key is not require to match that ACL.
30267 @item @code{action} (default: @code{'()})
30268 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
30269 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
30270 and @code{'update}.
30272 @item @code{deny?} (default: @code{#f})
30273 When true, the ACL defines restrictions. Listed actions are forbidden. When
30274 false, listed actions are allowed.
30279 @deftp {Data Type} zone-entry
30280 Data type representing a record entry in a zone file.
30281 This type has the following parameters:
30284 @item @code{name} (default: @code{"@@"})
30285 The name of the record. @code{"@@"} refers to the origin of the zone. Names
30286 are relative to the origin of the zone. For example, in the @code{example.org}
30287 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
30288 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
30289 refers to @code{ns.example.org}.
30291 @item @code{ttl} (default: @code{""})
30292 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
30294 @item @code{class} (default: @code{"IN"})
30295 The class of the record. Knot currently supports only @code{"IN"} and
30296 partially @code{"CH"}.
30298 @item @code{type} (default: @code{"A"})
30299 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
30300 address), NS (Name Server) and MX (Mail eXchange). Many other types are
30303 @item @code{data} (default: @code{""})
30304 The data contained in the record. For instance an IP address associated with
30305 an A record, or a domain name associated with an NS record. Remember that
30306 domain names are relative to the origin unless they end with a dot.
30311 @deftp {Data Type} zone-file
30312 Data type representing the content of a zone file.
30313 This type has the following parameters:
30316 @item @code{entries} (default: @code{'()})
30317 The list of entries. The SOA record is taken care of, so you don't need to
30318 put it in the list of entries. This list should probably contain an entry
30319 for your primary authoritative DNS server. Other than using a list of entries
30320 directly, you can use @code{define-zone-entries} to define a object containing
30321 the list of entries more easily, that you can later pass to the @code{entries}
30322 field of the @code{zone-file}.
30324 @item @code{origin} (default: @code{""})
30325 The name of your zone. This parameter cannot be empty.
30327 @item @code{ns} (default: @code{"ns"})
30328 The domain of your primary authoritative DNS server. The name is relative to
30329 the origin, unless it ends with a dot. It is mandatory that this primary
30330 DNS server corresponds to an NS record in the zone and that it is associated
30331 to an IP address in the list of entries.
30333 @item @code{mail} (default: @code{"hostmaster"})
30334 An email address people can contact you at, as the owner of the zone. This
30335 is translated as @code{<mail>@@<origin>}.
30337 @item @code{serial} (default: @code{1})
30338 The serial number of the zone. As this is used to keep track of changes by
30339 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
30340 Always increment it when you make a change in your zone.
30342 @item @code{refresh} (default: @code{(* 2 24 3600)})
30343 The frequency at which slaves will do a zone transfer. This value is a number
30344 of seconds. It can be computed by multiplications or with
30345 @code{(string->duration)}.
30347 @item @code{retry} (default: @code{(* 15 60)})
30348 The period after which a slave will retry to contact its master when it fails
30349 to do so a first time.
30351 @item @code{expiry} (default: @code{(* 14 24 3600)})
30352 Default TTL of records. Existing records are considered correct for at most
30353 this amount of time. After this period, resolvers will invalidate their cache
30354 and check again that it still exists.
30356 @item @code{nx} (default: @code{3600})
30357 Default TTL of inexistent records. This delay is usually short because you want
30358 your new domains to reach everyone quickly.
30363 @deftp {Data Type} knot-remote-configuration
30364 Data type representing a remote configuration.
30365 This type has the following parameters:
30368 @item @code{id} (default: @code{""})
30369 An identifier for other configuration fields to refer to this remote. IDs must
30370 be unique and must not be empty.
30372 @item @code{address} (default: @code{'()})
30373 An ordered list of destination IP addresses. Addresses are tried in sequence.
30374 An optional port can be given with the @@ separator. For instance:
30375 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
30377 @item @code{via} (default: @code{'()})
30378 An ordered list of source IP addresses. An empty list will have Knot choose
30379 an appropriate source IP@. An optional port can be given with the @@ separator.
30380 The default is to choose at random.
30382 @item @code{key} (default: @code{#f})
30383 A reference to a key, that is a string containing the identifier of a key
30384 defined in a @code{knot-key-configuration} field.
30389 @deftp {Data Type} knot-keystore-configuration
30390 Data type representing a keystore to hold dnssec keys.
30391 This type has the following parameters:
30394 @item @code{id} (default: @code{""})
30395 The id of the keystore. It must not be empty.
30397 @item @code{backend} (default: @code{'pem})
30398 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
30400 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
30401 The configuration string of the backend. An example for the PKCS#11 is:
30402 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
30403 For the pem backend, the string represents a path in the file system.
30408 @deftp {Data Type} knot-policy-configuration
30409 Data type representing a dnssec policy. Knot DNS is able to automatically
30410 sign your zones. It can either generate and manage your keys automatically or
30411 use keys that you generate.
30413 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
30414 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
30415 zone. In order to be trusted, the KSK needs to be present in the parent zone
30416 (usually a top-level domain). If your registrar supports dnssec, you will
30417 have to send them your KSK's hash so they can add a DS record in their zone.
30418 This is not automated and need to be done each time you change your KSK.
30420 The policy also defines the lifetime of keys. Usually, ZSK can be changed
30421 easily and use weaker cryptographic functions (they use lower parameters) in
30422 order to sign records quickly, so they are changed often. The KSK however
30423 requires manual interaction with the registrar, so they are changed less often
30424 and use stronger parameters because they sign only one record.
30426 This type has the following parameters:
30429 @item @code{id} (default: @code{""})
30430 The id of the policy. It must not be empty.
30432 @item @code{keystore} (default: @code{"default"})
30433 A reference to a keystore, that is a string containing the identifier of a
30434 keystore defined in a @code{knot-keystore-configuration} field. The
30435 @code{"default"} identifier means the default keystore (a kasp database that
30436 was setup by this service).
30438 @item @code{manual?} (default: @code{#f})
30439 Whether the key management is manual or automatic.
30441 @item @code{single-type-signing?} (default: @code{#f})
30442 When @code{#t}, use the Single-Type Signing Scheme.
30444 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
30445 An algorithm of signing keys and issued signatures.
30447 @item @code{ksk-size} (default: @code{256})
30448 The length of the KSK@. Note that this value is correct for the default
30449 algorithm, but would be unsecure for other algorithms.
30451 @item @code{zsk-size} (default: @code{256})
30452 The length of the ZSK@. Note that this value is correct for the default
30453 algorithm, but would be unsecure for other algorithms.
30455 @item @code{dnskey-ttl} (default: @code{'default})
30456 The TTL value for DNSKEY records added into zone apex. The special
30457 @code{'default} value means same as the zone SOA TTL.
30459 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
30460 The period between ZSK publication and the next rollover initiation.
30462 @item @code{propagation-delay} (default: @code{(* 24 3600)})
30463 An extra delay added for each key rollover step. This value should be high
30464 enough to cover propagation of data from the master server to all slaves.
30466 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
30467 A validity period of newly issued signatures.
30469 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
30470 A period how long before a signature expiration the signature will be refreshed.
30472 @item @code{nsec3?} (default: @code{#f})
30473 When @code{#t}, NSEC3 will be used instead of NSEC.
30475 @item @code{nsec3-iterations} (default: @code{5})
30476 The number of additional times the hashing is performed.
30478 @item @code{nsec3-salt-length} (default: @code{8})
30479 The length of a salt field in octets, which is appended to the original owner
30480 name before hashing.
30482 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
30483 The validity period of newly issued salt field.
30488 @deftp {Data Type} knot-zone-configuration
30489 Data type representing a zone served by Knot.
30490 This type has the following parameters:
30493 @item @code{domain} (default: @code{""})
30494 The domain served by this configuration. It must not be empty.
30496 @item @code{file} (default: @code{""})
30497 The file where this zone is saved. This parameter is ignored by master zones.
30498 Empty means default location that depends on the domain name.
30500 @item @code{zone} (default: @code{(zone-file)})
30501 The content of the zone file. This parameter is ignored by slave zones. It
30502 must contain a zone-file record.
30504 @item @code{master} (default: @code{'()})
30505 A list of master remotes. When empty, this zone is a master. When set, this
30506 zone is a slave. This is a list of remotes identifiers.
30508 @item @code{ddns-master} (default: @code{#f})
30509 The main master. When empty, it defaults to the first master in the list of
30512 @item @code{notify} (default: @code{'()})
30513 A list of slave remote identifiers.
30515 @item @code{acl} (default: @code{'()})
30516 A list of acl identifiers.
30518 @item @code{semantic-checks?} (default: @code{#f})
30519 When set, this adds more semantic checks to the zone.
30521 @item @code{zonefile-sync} (default: @code{0})
30522 The delay between a modification in memory and on disk. 0 means immediate
30525 @item @code{zonefile-load} (default: @code{#f})
30526 The way the zone file contents are applied during zone load. Possible values
30530 @item @code{#f} for using the default value from Knot,
30531 @item @code{'none} for not using the zone file at all,
30532 @item @code{'difference} for computing the difference between already available
30533 contents and zone contents and applying it to the current zone contents,
30534 @item @code{'difference-no-serial} for the same as @code{'difference}, but
30535 ignoring the SOA serial in the zone file, while the server takes care of it
30537 @item @code{'whole} for loading zone contents from the zone file.
30540 @item @code{journal-content} (default: @code{#f})
30541 The way the journal is used to store zone and its changes. Possible values
30542 are @code{'none} to not use it at all, @code{'changes} to store changes and
30543 @code{'all} to store contents. @code{#f} does not set this option, so the
30544 default value from Knot is used.
30546 @item @code{max-journal-usage} (default: @code{#f})
30547 The maximum size for the journal on disk. @code{#f} does not set this option,
30548 so the default value from Knot is used.
30550 @item @code{max-journal-depth} (default: @code{#f})
30551 The maximum size of the history. @code{#f} does not set this option, so the
30552 default value from Knot is used.
30554 @item @code{max-zone-size} (default: @code{#f})
30555 The maximum size of the zone file. This limit is enforced for incoming
30556 transfer and updates. @code{#f} does not set this option, so the default
30557 value from Knot is used.
30559 @item @code{dnssec-policy} (default: @code{#f})
30560 A reference to a @code{knot-policy-configuration} record, or the special
30561 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
30564 @item @code{serial-policy} (default: @code{'increment})
30565 A policy between @code{'increment} and @code{'unixtime}.
30570 @deftp {Data Type} knot-configuration
30571 Data type representing the Knot configuration.
30572 This type has the following parameters:
30575 @item @code{knot} (default: @code{knot})
30578 @item @code{run-directory} (default: @code{"/var/run/knot"})
30579 The run directory. This directory will be used for pid file and sockets.
30581 @item @code{includes} (default: @code{'()})
30582 A list of strings or file-like objects denoting other files that must be
30583 included at the top of the configuration file.
30585 @cindex secrets, Knot service
30586 This can be used to manage secrets out-of-band. For example, secret
30587 keys may be stored in an out-of-band file not managed by Guix, and
30588 thus not visible in @file{/gnu/store}---e.g., you could store secret
30589 key configuration in @file{/etc/knot/secrets.conf} and add this file
30590 to the @code{includes} list.
30592 One can generate a secret tsig key (for nsupdate and zone transfers with the
30593 keymgr command from the knot package. Note that the package is not automatically
30594 installed by the service. The following example shows how to generate a new
30598 keymgr -t mysecret > /etc/knot/secrets.conf
30599 chmod 600 /etc/knot/secrets.conf
30602 Also note that the generated key will be named @var{mysecret}, so it is the
30603 name that needs to be used in the @var{key} field of the
30604 @code{knot-acl-configuration} record and in other places that need to refer
30607 It can also be used to add configuration not supported by this interface.
30609 @item @code{listen-v4} (default: @code{"0.0.0.0"})
30610 An ip address on which to listen.
30612 @item @code{listen-v6} (default: @code{"::"})
30613 An ip address on which to listen.
30615 @item @code{listen-port} (default: @code{53})
30616 A port on which to listen.
30618 @item @code{keys} (default: @code{'()})
30619 The list of knot-key-configuration used by this configuration.
30621 @item @code{acls} (default: @code{'()})
30622 The list of knot-acl-configuration used by this configuration.
30624 @item @code{remotes} (default: @code{'()})
30625 The list of knot-remote-configuration used by this configuration.
30627 @item @code{zones} (default: @code{'()})
30628 The list of knot-zone-configuration used by this configuration.
30633 @subsubheading Knot Resolver Service
30635 @deffn {Scheme Variable} knot-resolver-service-type
30636 This is the type of the knot resolver service, whose value should be
30637 an @code{knot-resolver-configuration} object as in this example:
30640 (service knot-resolver-service-type
30641 (knot-resolver-configuration
30642 (kresd-config-file (plain-file "kresd.conf" "
30643 net.listen('192.168.0.1', 5353)
30644 user('knot-resolver', 'knot-resolver')
30645 modules = @{ 'hints > iterate', 'stats', 'predict' @}
30646 cache.size = 100 * MB
30650 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
30653 @deftp {Data Type} knot-resolver-configuration
30654 Data type representing the configuration of knot-resolver.
30657 @item @code{package} (default: @var{knot-resolver})
30658 Package object of the knot DNS resolver.
30660 @item @code{kresd-config-file} (default: %kresd.conf)
30661 File-like object of the kresd configuration file to use, by default it
30662 will listen on @code{127.0.0.1} and @code{::1}.
30664 @item @code{garbage-collection-interval} (default: 1000)
30665 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
30671 @subsubheading Dnsmasq Service
30673 @deffn {Scheme Variable} dnsmasq-service-type
30674 This is the type of the dnsmasq service, whose value should be an
30675 @code{dnsmasq-configuration} object as in this example:
30678 (service dnsmasq-service-type
30679 (dnsmasq-configuration
30681 (servers '("192.168.1.1"))))
30685 @deftp {Data Type} dnsmasq-configuration
30686 Data type representing the configuration of dnsmasq.
30689 @item @code{package} (default: @var{dnsmasq})
30690 Package object of the dnsmasq server.
30692 @item @code{no-hosts?} (default: @code{#f})
30693 When true, don't read the hostnames in /etc/hosts.
30695 @item @code{port} (default: @code{53})
30696 The port to listen on. Setting this to zero completely disables DNS
30697 responses, leaving only DHCP and/or TFTP functions.
30699 @item @code{local-service?} (default: @code{#t})
30700 Accept DNS queries only from hosts whose address is on a local subnet,
30701 ie a subnet for which an interface exists on the server.
30703 @item @code{listen-addresses} (default: @code{'()})
30704 Listen on the given IP addresses.
30706 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
30707 The file to read the IP address of the upstream nameservers from.
30709 @item @code{no-resolv?} (default: @code{#f})
30710 When true, don't read @var{resolv-file}.
30712 @item @code{forward-private-reverse-lookup?} (default: @code{#t})
30713 When false, all reverse lookups for private IP ranges are answered with
30714 "no such domain" rather than being forwarded upstream.
30716 @item @code{query-servers-in-order?} (default: @code{#f})
30717 When true, dnsmasq queries the servers in the same order as they appear
30720 @item @code{servers} (default: @code{'()})
30721 Specify IP address of upstream servers directly.
30723 @item @code{addresses} (default: @code{'()})
30724 For each entry, specify an IP address to return for any host in the
30725 given domains. Queries in the domains are never forwarded and always
30726 replied to with the specified IP address.
30728 This is useful for redirecting hosts locally, for example:
30731 (service dnsmasq-service-type
30732 (dnsmasq-configuration
30734 '(; Redirect to a local web-server.
30735 "/example.org/127.0.0.1"
30736 ; Redirect subdomain to a specific IP.
30737 "/subdomain.example.org/192.168.1.42"))))
30740 Note that rules in @file{/etc/hosts} take precedence over this.
30742 @item @code{cache-size} (default: @code{150})
30743 Set the size of dnsmasq's cache. Setting the cache size to zero
30746 @item @code{negative-cache?} (default: @code{#t})
30747 When false, disable negative caching.
30749 @item @code{cpe-id} (default: @code{#f})
30750 If set, add a CPE (Customer-Premises Equipment) identifier to DNS
30751 queries which are forwarded upstream.
30753 @item @code{tftp-enable?} (default: @code{#f})
30754 Whether to enable the built-in TFTP server.
30756 @item @code{tftp-no-fail?} (default: @code{#f})
30757 If true, does not fail dnsmasq if the TFTP server could not start up.
30759 @item @code{tftp-single-port?} (default: @code{#f})
30760 Whether to use only one single port for TFTP.
30762 @item @code{tftp-secure?} (default: @code{#f})
30763 If true, only files owned by the user running the dnsmasq process are accessible.
30765 If dnsmasq is being run as root, different rules apply:
30766 @code{tftp-secure?} has no effect, but only files which have the
30767 world-readable bit set are accessible.
30769 @item @code{tftp-max} (default: @code{#f})
30770 If set, sets the maximal number of concurrent connections allowed.
30772 @item @code{tftp-mtu} (default: @code{#f})
30773 If set, sets the MTU for TFTP packets to that value.
30775 @item @code{tftp-no-blocksize?} (default: @code{#f})
30776 If true, stops the TFTP server from negotiating the blocksize with a client.
30778 @item @code{tftp-lowercase?} (default: @code{#f})
30779 Whether to convert all filenames in TFTP requests to lowercase.
30781 @item @code{tftp-port-range} (default: @code{#f})
30782 If set, fixes the dynamical ports (one per client) to the given range
30783 (@code{"<start>,<end>"}).
30785 @item @code{tftp-root} (default: @code{/var/empty,lo})
30786 Look for files to transfer using TFTP relative to the given directory.
30787 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
30788 getting outside the specified root. Absolute paths (starting with @samp{/}) are
30789 allowed, but they must be within the TFTP-root. If the optional interface
30790 argument is given, the directory is only used for TFTP requests via that
30793 @item @code{tftp-unique-root} (default: @code{#f})
30794 If set, add the IP or hardware address of the TFTP client as a path component
30795 on the end of the TFTP-root. Only valid if a TFTP root is set and the
30796 directory exists. Defaults to adding IP address (in standard dotted-quad
30799 For instance, if @option{--tftp-root} is @samp{/tftp} and client
30800 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
30801 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
30802 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
30803 append the MAC address instead, using lowercase zero padded digits
30804 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
30805 resolving MAC addresses is only possible if the client is in the local
30806 network or obtained a DHCP lease from dnsmasq.
30811 @subsubheading ddclient Service
30814 The ddclient service described below runs the ddclient daemon, which takes
30815 care of automatically updating DNS entries for service providers such as
30816 @uref{https://dyn.com/dns/, Dyn}.
30818 The following example show instantiates the service with its default
30822 (service ddclient-service-type)
30825 Note that ddclient needs to access credentials that are stored in a
30826 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
30827 @code{secret-file} below). You are expected to create this file manually, in
30828 an ``out-of-band'' fashion (you @emph{could} make this file part of the
30829 service configuration, for instance by using @code{plain-file}, but it will be
30830 world-readable @i{via} @file{/gnu/store}). See the examples in the
30831 @file{share/ddclient} directory of the @code{ddclient} package.
30833 @c %start of fragment
30835 Available @code{ddclient-configuration} fields are:
30837 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
30838 The ddclient package.
30842 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
30843 The period after which ddclient will retry to check IP and domain name.
30845 Defaults to @samp{300}.
30849 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
30850 Use syslog for the output.
30852 Defaults to @samp{#t}.
30856 @deftypevr {@code{ddclient-configuration} parameter} string mail
30859 Defaults to @samp{"root"}.
30863 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
30864 Mail failed update to user.
30866 Defaults to @samp{"root"}.
30870 @deftypevr {@code{ddclient-configuration} parameter} string pid
30871 The ddclient PID file.
30873 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
30877 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
30878 Enable SSL support.
30880 Defaults to @samp{#t}.
30884 @deftypevr {@code{ddclient-configuration} parameter} string user
30885 Specifies the user name or ID that is used when running ddclient
30888 Defaults to @samp{"ddclient"}.
30892 @deftypevr {@code{ddclient-configuration} parameter} string group
30893 Group of the user who will run the ddclient program.
30895 Defaults to @samp{"ddclient"}.
30899 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
30900 Secret file which will be appended to @file{ddclient.conf} file. This
30901 file contains credentials for use by ddclient. You are expected to
30902 create it manually.
30904 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
30908 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
30909 Extra options will be appended to @file{ddclient.conf} file.
30911 Defaults to @samp{()}.
30916 @c %end of fragment
30919 @subsection VNC Services
30920 @cindex VNC (virtual network computing)
30921 @cindex XDMCP (x display manager control protocol)
30923 The @code{(gnu services vnc)} module provides services related to
30924 @dfn{Virtual Network Computing} (VNC), which makes it possible to
30925 locally use graphical Xorg applications running on a remote machine.
30926 Combined with a graphical manager that supports the @dfn{X Display
30927 Manager Control Protocol}, such as GDM (@pxref{gdm}) or LightDM
30928 (@pxref{lightdm}), it is possible to remote an entire desktop for a
30929 multi-user environment.
30931 @subsubheading Xvnc
30933 Xvnc is a VNC server that spawns its own X window server; which means it
30934 can run on headless servers. The Xvnc implementations provided by the
30935 @code{tigervnc-server} and @code{turbovnc} aim to be fast and efficient.
30937 @defvar {Scheme Variable} xvnc-service-type
30939 The @code{xvnc-server-type} service can be configured via the
30940 @code{xvnc-configuration} record, documented below. A second virtual
30941 display could be made available on a remote machine for via the
30942 following configuration:
30946 (service xvnc-service-type (xvnc-configuration (display-number 10)
30949 As a demonstration, the @command{xclock} command could then be started
30950 on the remote machine on display number 10, and it could be display
30951 locally via the @command{vncviewer} command:
30953 # Start xclock on the remote machine.
30954 ssh -L5910:localhost:5910 -- guix shell xclock -- env DISPLAY=:10 xclock
30955 # Access it via VNC.
30956 guix shell tigervnc-client -- vncviewer localhost:5910
30959 The following configuration combines XDMCP and Inetd to allow multiple
30960 users to concurrently use the remote system, login in graphically via
30961 the GDM display manager:
30968 (service xvnc-service-type (xvnc-configuration
30973 (modify-services %desktop-services
30974 (gdm-service-type config => (gdm-configuration
30980 A remote user could then connect to it by using the @command{vncviewer}
30981 command or a compatible VNC client and start a desktop session of their
30984 vncviewer remote-host:5905
30988 Unless your machine is in a controlled environment, for security
30989 reasons, the @code{localhost?} configuration of the
30990 @code{xvnc-configuration} record should be left to its default @code{#t}
30991 value and exposed via a secure means such as an SSH port forward. The
30992 XDMCP port, UDP 177 should also be blocked from the outside by a
30993 firewall, as it is not a secure protocol and can expose login
30994 credentials in clear.
30997 @c Use (configuration->documentation 'xvnc-configuration) to regenerate
30998 @c the documentation.
30999 @c %start of fragment
31000 @deftp {Data Type} xvnc-configuration
31001 Available @code{xvnc-configuration} fields are:
31004 @item @code{xvnc} (default: @code{tigervnc-server}) (type: file-like)
31005 The package that provides the Xvnc binary.
31007 @item @code{display-number} (default: @code{0}) (type: number)
31008 The display number used by Xvnc. You should set this to a number not
31009 already used a Xorg server.
31011 @item @code{geometry} (default: @code{"1024x768"}) (type: string)
31012 The size of the desktop to be created.
31014 @item @code{depth} (default: @code{24}) (type: color-depth)
31015 The pixel depth in bits of the desktop to be created. Accepted values
31018 @item @code{port} (type: maybe-port)
31019 The port on which to listen for connections from viewers. When left
31020 unspecified, it defaults to 5900 plus the display number.
31022 @item @code{ipv4?} (default: @code{#t}) (type: boolean)
31023 Use IPv4 for incoming and outgoing connections.
31025 @item @code{ipv6?} (default: @code{#t}) (type: boolean)
31026 Use IPv6 for incoming and outgoing connections.
31028 @item @code{password-file} (type: maybe-string)
31029 The password file to use, if any. Refer to vncpasswd(1) to learn how to
31030 generate such a file.
31032 @item @code{xdmcp?} (default: @code{#f}) (type: boolean)
31033 Query the XDMCP server for a session. This enables users to log in a
31034 desktop session from the login manager screen. For a multiple users
31035 scenario, you'll want to enable the @code{inetd?} option as well, so
31036 that each connection to the VNC server is handled separately rather than
31039 @item @code{inetd?} (default: @code{#f}) (type: boolean)
31040 Use an Inetd-style service, which runs the Xvnc server on demand.
31042 @item @code{frame-rate} (default: @code{60}) (type: number)
31043 The maximum number of updates per second sent to each client.
31045 @item @code{security-types} (default: @code{("None")}) (type: security-types)
31046 The allowed security schemes to use for incoming connections. The
31047 default is "None", which is safe given that Xvnc is configured to
31048 authenticate the user via the display manager, and only for local
31049 connections. Accepted values are any of the following: ("None"
31050 "VncAuth" "Plain" "TLSNone" "TLSVnc" "TLSPlain" "X509None" "X509Vnc")
31052 @item @code{localhost?} (default: @code{#t}) (type: boolean)
31053 Only allow connections from the same machine. It is set to #true by
31054 default for security, which means SSH or another secure means should be
31055 used to expose the remote port.
31057 @item @code{log-level} (default: @code{30}) (type: log-level)
31058 The log level, a number between 0 and 100, 100 meaning most verbose
31059 output. The log messages are output to syslog.
31061 @item @code{extra-options} (default: @code{()}) (type: strings)
31062 This can be used to provide extra Xvnc options not exposed via this
31063 <xvnc-configuration> record.
31068 @c %end of fragment
31071 @subsection VPN Services
31072 @cindex VPN (virtual private network)
31073 @cindex virtual private network (VPN)
31075 The @code{(gnu services vpn)} module provides services related to
31076 @dfn{virtual private networks} (VPNs).
31078 @subsubheading Bitmask
31080 @defvr {Scheme Variable} bitmask-service-type
31081 A service type for the @uref{https://bitmask.net, Bitmask} VPN client. It makes
31082 the client available in the system and loads its polkit policy. Please note that
31083 the client expects an active polkit-agent, which is either run by your
31084 desktop-environment or should be run manually.
31087 @subsubheading OpenVPN
31089 It provides a @emph{client} service for your machine to connect to a
31090 VPN, and a @emph{server} service for your machine to host a VPN@.
31092 @deffn {Scheme Procedure} openvpn-client-service @
31093 [#:config (openvpn-client-configuration)]
31095 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
31098 @deffn {Scheme Procedure} openvpn-server-service @
31099 [#:config (openvpn-server-configuration)]
31101 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
31103 Both can be run simultaneously.
31106 @c %automatically generated documentation
31108 @deftp {Data Type} openvpn-client-configuration
31109 Available @code{openvpn-client-configuration} fields are:
31112 @item @code{openvpn} (default: @code{openvpn}) (type: file-like)
31113 The OpenVPN package.
31115 @item @code{pid-file} (default: @code{"/var/run/openvpn/openvpn.pid"}) (type: string)
31116 The OpenVPN pid file.
31118 @item @code{proto} (default: @code{udp}) (type: proto)
31119 The protocol (UDP or TCP) used to open a channel between clients and
31122 @item @code{dev} (default: @code{tun}) (type: dev)
31123 The device type used to represent the VPN connection.
31125 @item @code{ca} (default: @code{"/etc/openvpn/ca.crt"}) (type: maybe-string)
31126 The certificate authority to check connections against.
31128 @item @code{cert} (default: @code{"/etc/openvpn/client.crt"}) (type: maybe-string)
31129 The certificate of the machine the daemon is running on. It should be
31130 signed by the authority given in @code{ca}.
31132 @item @code{key} (default: @code{"/etc/openvpn/client.key"}) (type: maybe-string)
31133 The key of the machine the daemon is running on. It must be the key
31134 whose certificate is @code{cert}.
31136 @item @code{comp-lzo?} (default: @code{#t}) (type: boolean)
31137 Whether to use the lzo compression algorithm.
31139 @item @code{persist-key?} (default: @code{#t}) (type: boolean)
31140 Don't re-read key files across SIGUSR1 or --ping-restart.
31142 @item @code{persist-tun?} (default: @code{#t}) (type: boolean)
31143 Don't close and reopen TUN/TAP device or run up/down scripts across
31144 SIGUSR1 or --ping-restart restarts.
31146 @item @code{fast-io?} (default: @code{#f}) (type: boolean)
31147 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
31148 poll/epoll/select prior to the write operation.
31150 @item @code{verbosity} (default: @code{3}) (type: number)
31153 @item @code{tls-auth} (default: @code{#f}) (type: tls-auth-client)
31154 Add an additional layer of HMAC authentication on top of the TLS control
31155 channel to protect against DoS attacks.
31157 @item @code{auth-user-pass} (type: maybe-string)
31158 Authenticate with server using username/password. The option is a file
31159 containing username/password on 2 lines. Do not use a file-like object
31160 as it would be added to the store and readable by any user.
31162 @item @code{verify-key-usage?} (default: @code{#t}) (type: key-usage)
31163 Whether to check the server certificate has server usage extension.
31165 @item @code{bind?} (default: @code{#f}) (type: bind)
31166 Bind to a specific local port number.
31168 @item @code{resolv-retry?} (default: @code{#t}) (type: resolv-retry)
31169 Retry resolving server address.
31171 @item @code{remote} (default: @code{()}) (type: openvpn-remote-list)
31172 A list of remote servers to connect to.
31174 @deftp {Data Type} openvpn-remote-configuration
31175 Available @code{openvpn-remote-configuration} fields are:
31178 @item @code{name} (default: @code{"my-server"}) (type: string)
31181 @item @code{port} (default: @code{1194}) (type: number)
31182 Port number the server listens to.
31192 @c %end of automatic openvpn-client documentation
31194 @c %automatically generated documentation
31196 @deftp {Data Type} openvpn-server-configuration
31197 Available @code{openvpn-server-configuration} fields are:
31200 @item @code{openvpn} (default: @code{openvpn}) (type: file-like)
31201 The OpenVPN package.
31203 @item @code{pid-file} (default: @code{"/var/run/openvpn/openvpn.pid"}) (type: string)
31204 The OpenVPN pid file.
31206 @item @code{proto} (default: @code{udp}) (type: proto)
31207 The protocol (UDP or TCP) used to open a channel between clients and
31210 @item @code{dev} (default: @code{tun}) (type: dev)
31211 The device type used to represent the VPN connection.
31213 @item @code{ca} (default: @code{"/etc/openvpn/ca.crt"}) (type: maybe-string)
31214 The certificate authority to check connections against.
31216 @item @code{cert} (default: @code{"/etc/openvpn/client.crt"}) (type: maybe-string)
31217 The certificate of the machine the daemon is running on. It should be
31218 signed by the authority given in @code{ca}.
31220 @item @code{key} (default: @code{"/etc/openvpn/client.key"}) (type: maybe-string)
31221 The key of the machine the daemon is running on. It must be the key
31222 whose certificate is @code{cert}.
31224 @item @code{comp-lzo?} (default: @code{#t}) (type: boolean)
31225 Whether to use the lzo compression algorithm.
31227 @item @code{persist-key?} (default: @code{#t}) (type: boolean)
31228 Don't re-read key files across SIGUSR1 or --ping-restart.
31230 @item @code{persist-tun?} (default: @code{#t}) (type: boolean)
31231 Don't close and reopen TUN/TAP device or run up/down scripts across
31232 SIGUSR1 or --ping-restart restarts.
31234 @item @code{fast-io?} (default: @code{#f}) (type: boolean)
31235 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
31236 poll/epoll/select prior to the write operation.
31238 @item @code{verbosity} (default: @code{3}) (type: number)
31241 @item @code{tls-auth} (default: @code{#f}) (type: tls-auth-server)
31242 Add an additional layer of HMAC authentication on top of the TLS control
31243 channel to protect against DoS attacks.
31245 @item @code{port} (default: @code{1194}) (type: number)
31246 Specifies the port number on which the server listens.
31248 @item @code{server} (default: @code{"10.8.0.0 255.255.255.0"}) (type: ip-mask)
31249 An ip and mask specifying the subnet inside the virtual network.
31251 @item @code{server-ipv6} (default: @code{#f}) (type: cidr6)
31252 A CIDR notation specifying the IPv6 subnet inside the virtual network.
31254 @item @code{dh} (default: @code{"/etc/openvpn/dh2048.pem"}) (type: string)
31255 The Diffie-Hellman parameters file.
31257 @item @code{ifconfig-pool-persist} (default: @code{"/etc/openvpn/ipp.txt"}) (type: string)
31258 The file that records client IPs.
31260 @item @code{redirect-gateway?} (default: @code{#f}) (type: gateway)
31261 When true, the server will act as a gateway for its clients.
31263 @item @code{client-to-client?} (default: @code{#f}) (type: boolean)
31264 When true, clients are allowed to talk to each other inside the VPN.
31266 @item @code{keepalive} (default: @code{(10 120)}) (type: keepalive)
31267 Causes ping-like messages to be sent back and forth over the link so
31268 that each side knows when the other side has gone down. @code{keepalive}
31269 requires a pair. The first element is the period of the ping sending,
31270 and the second element is the timeout before considering the other side
31273 @item @code{max-clients} (default: @code{100}) (type: number)
31274 The maximum number of clients.
31276 @item @code{status} (default: @code{"/var/run/openvpn/status"}) (type: string)
31277 The status file. This file shows a small report on current connection.
31278 It is truncated and rewritten every minute.
31280 @item @code{client-config-dir} (default: @code{()}) (type: openvpn-ccd-list)
31281 The list of configuration for some clients.
31287 @c %end of automatic openvpn-server documentation
31289 @subheading strongSwan
31291 Currently, the strongSwan service only provides legacy-style configuration with
31292 @file{ipsec.conf} and @file{ipsec.secrets} files.
31294 @defvr {Scheme Variable} strongswan-service-type
31295 A service type for configuring strongSwan for IPsec @acronym{VPN,
31296 Virtual Private Networking}. Its value must be a
31297 @code{strongswan-configuration} record as in this example:
31300 (service strongswan-service-type
31301 (strongswan-configuration
31302 (ipsec-conf "/etc/ipsec.conf")
31303 (ipsec-secrets "/etc/ipsec.secrets")))
31308 @deftp {Data Type} strongswan-configuration
31309 Data type representing the configuration of the StrongSwan service.
31312 @item @code{strongswan}
31313 The strongSwan package to use for this service.
31315 @item @code{ipsec-conf} (default: @code{#f})
31316 The file name of your @file{ipsec.conf}. If not @code{#f}, then this and
31317 @code{ipsec-secrets} must both be strings.
31319 @item @code{ipsec-secrets} (default @code{#f})
31320 The file name of your @file{ipsec.secrets}. If not @code{#f}, then this and
31321 @code{ipsec-conf} must both be strings.
31326 @subsubheading Wireguard
31328 @defvr {Scheme Variable} wireguard-service-type
31329 A service type for a Wireguard tunnel interface. Its value must be a
31330 @code{wireguard-configuration} record as in this example:
31333 (service wireguard-service-type
31334 (wireguard-configuration
31339 (endpoint "my.wireguard.com:51820")
31340 (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
31341 (allowed-ips '("10.0.0.2/32")))))))
31346 @deftp {Data Type} wireguard-configuration
31347 Data type representing the configuration of the Wireguard service.
31350 @item @code{wireguard}
31351 The wireguard package to use for this service.
31353 @item @code{interface} (default: @code{"wg0"})
31354 The interface name for the VPN.
31356 @item @code{addresses} (default: @code{'("10.0.0.1/32")})
31357 The IP addresses to be assigned to the above interface.
31359 @item @code{port} (default: @code{51820})
31360 The port on which to listen for incoming connections.
31362 @item @code{dns} (default: @code{#f})
31363 The DNS server(s) to announce to VPN clients via DHCP.
31365 @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
31366 The private key file for the interface. It is automatically generated if
31367 the file does not exist.
31369 @item @code{peers} (default: @code{'()})
31370 The authorized peers on this interface. This is a list of
31371 @var{wireguard-peer} records.
31376 @deftp {Data Type} wireguard-peer
31377 Data type representing a Wireguard peer attached to a given interface.
31383 @item @code{endpoint} (default: @code{#f})
31384 The optional endpoint for the peer, such as
31385 @code{"demo.wireguard.com:51820"}.
31387 @item @code{public-key}
31388 The peer public-key represented as a base64 string.
31390 @item @code{allowed-ips}
31391 A list of IP addresses from which incoming traffic for this peer is
31392 allowed and to which incoming traffic for this peer is directed.
31394 @item @code{keep-alive} (default: @code{#f})
31395 An optional time interval in seconds. A packet will be sent to the
31396 server endpoint once per time interval. This helps receiving
31397 incoming connections from this peer when you are behind a NAT or
31403 @node Network File System
31404 @subsection Network File System
31407 The @code{(gnu services nfs)} module provides the following services,
31408 which are most commonly used in relation to mounting or exporting
31409 directory trees as @dfn{network file systems} (NFS).
31411 While it is possible to use the individual components that together make
31412 up a Network File System service, we recommended to configure an NFS
31413 server with the @code{nfs-service-type}.
31415 @subsubheading NFS Service
31416 @cindex NFS, server
31418 The NFS service takes care of setting up all NFS component services,
31419 kernel configuration file systems, and installs configuration files in
31420 the locations that NFS expects.
31422 @defvr {Scheme Variable} nfs-service-type
31423 A service type for a complete NFS server.
31426 @deftp {Data Type} nfs-configuration
31427 This data type represents the configuration of the NFS service and all
31430 It has the following parameters:
31432 @item @code{nfs-utils} (default: @code{nfs-utils})
31433 The nfs-utils package to use.
31435 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
31436 If a list of string values is provided, the @command{rpc.nfsd} daemon
31437 will be limited to supporting the given versions of the NFS protocol.
31439 @item @code{exports} (default: @code{'()})
31440 This is a list of directories the NFS server should export. Each entry
31441 is a list consisting of two elements: a directory name and a string
31442 containing all options. This is an example in which the directory
31443 @file{/export} is served to all NFS clients as a read-only share:
31449 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
31452 @item @code{rpcmountd-port} (default: @code{#f})
31453 The network port that the @command{rpc.mountd} daemon should use.
31455 @item @code{rpcstatd-port} (default: @code{#f})
31456 The network port that the @command{rpc.statd} daemon should use.
31458 @item @code{rpcbind} (default: @code{rpcbind})
31459 The rpcbind package to use.
31461 @item @code{idmap-domain} (default: @code{"localdomain"})
31462 The local NFSv4 domain name.
31464 @item @code{nfsd-port} (default: @code{2049})
31465 The network port that the @command{nfsd} daemon should use.
31467 @item @code{nfsd-threads} (default: @code{8})
31468 The number of threads used by the @command{nfsd} daemon.
31470 @item @code{nfsd-tcp?} (default: @code{#t})
31471 Whether the @command{nfsd} daemon should listen on a TCP socket.
31473 @item @code{nfsd-udp?} (default: @code{#f})
31474 Whether the @command{nfsd} daemon should listen on a UDP socket.
31476 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31477 The directory where the pipefs file system is mounted.
31479 @item @code{debug} (default: @code{'()"})
31480 A list of subsystems for which debugging output should be enabled. This
31481 is a list of symbols. Any of these symbols are valid: @code{nfsd},
31482 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
31486 If you don't need a complete NFS service or prefer to build it yourself
31487 you can use the individual component services that are documented below.
31489 @subsubheading RPC Bind Service
31492 The RPC Bind service provides a facility to map program numbers into
31493 universal addresses.
31494 Many NFS related services use this facility. Hence it is automatically
31495 started when a dependent service starts.
31497 @defvr {Scheme Variable} rpcbind-service-type
31498 A service type for the RPC portmapper daemon.
31502 @deftp {Data Type} rpcbind-configuration
31503 Data type representing the configuration of the RPC Bind Service.
31504 This type has the following parameters:
31506 @item @code{rpcbind} (default: @code{rpcbind})
31507 The rpcbind package to use.
31509 @item @code{warm-start?} (default: @code{#t})
31510 If this parameter is @code{#t}, then the daemon will read a
31511 state file on startup thus reloading state information saved by a previous
31517 @subsubheading Pipefs Pseudo File System
31521 The pipefs file system is used to transfer NFS related data
31522 between the kernel and user space programs.
31524 @defvr {Scheme Variable} pipefs-service-type
31525 A service type for the pipefs pseudo file system.
31528 @deftp {Data Type} pipefs-configuration
31529 Data type representing the configuration of the pipefs pseudo file system service.
31530 This type has the following parameters:
31532 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31533 The directory to which the file system is to be attached.
31538 @subsubheading GSS Daemon Service
31541 @cindex global security system
31543 The @dfn{global security system} (GSS) daemon provides strong security for RPC
31545 Before exchanging RPC requests an RPC client must establish a security
31546 context. Typically this is done using the Kerberos command @command{kinit}
31547 or automatically at login time using PAM services (@pxref{Kerberos Services}).
31549 @defvr {Scheme Variable} gss-service-type
31550 A service type for the Global Security System (GSS) daemon.
31553 @deftp {Data Type} gss-configuration
31554 Data type representing the configuration of the GSS daemon service.
31555 This type has the following parameters:
31557 @item @code{nfs-utils} (default: @code{nfs-utils})
31558 The package in which the @command{rpc.gssd} command is to be found.
31560 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31561 The directory where the pipefs file system is mounted.
31567 @subsubheading IDMAP Daemon Service
31569 @cindex name mapper
31571 The idmap daemon service provides mapping between user IDs and user names.
31572 Typically it is required in order to access file systems mounted via NFSv4.
31574 @defvr {Scheme Variable} idmap-service-type
31575 A service type for the Identity Mapper (IDMAP) daemon.
31578 @deftp {Data Type} idmap-configuration
31579 Data type representing the configuration of the IDMAP daemon service.
31580 This type has the following parameters:
31582 @item @code{nfs-utils} (default: @code{nfs-utils})
31583 The package in which the @command{rpc.idmapd} command is to be found.
31585 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31586 The directory where the pipefs file system is mounted.
31588 @item @code{domain} (default: @code{#f})
31589 The local NFSv4 domain name.
31590 This must be a string or @code{#f}.
31591 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
31593 @item @code{verbosity} (default: @code{0})
31594 The verbosity level of the daemon.
31599 @node Samba Services, Continuous Integration, Network File System, Services
31600 @subsection Samba Services
31604 The @code{(gnu services samba)} module provides service definitions for
31605 Samba as well as additional helper services. Currently it provides the
31606 following services.
31608 @subsubheading Samba
31610 @uref{https://www.samba.org, Samba} provides network shares for folders
31611 and printers using the SMB/CIFS protocol commonly used on Windows. It
31612 can also act as an Active Directory Domain Controller (AD DC) for other
31613 hosts in an heterougenious network with different types of Computer
31616 @defvar {Scheme variable} samba-service-type
31618 The service type to enable the samba services @code{samba}, @code{nmbd},
31619 @code{smbd} and @code{winbindd}. By default this service type does not
31620 run any of the Samba daemons; they must be enabled individually.
31622 Below is a basic example that configures a simple, anonymous
31623 (unauthenticated) Samba file share exposing the @file{/public}
31627 The @file{/public} directory and its contents must be world
31628 readable/writable, so you'll want to run @samp{chmod -R 777 /public} on
31633 Such a Samba configuration should only be used in controlled
31634 environments, and you should not share any private files using it, as
31635 anyone connecting to your network would be able to access them.
31639 (service samba-service-type (samba-configuration
31641 (config-file (plain-file "smb.conf" "\
31643 map to guest = Bad User
31644 logging = syslog@@1
31651 guest only = yes\n"))))
31656 @deftp{Data Type} samba-service-configuration
31657 Configuration record for the Samba suite.
31660 @item @code{package} (default: @code{samba})
31661 The samba package to use.
31663 @item @code{config-file} (default: @code{#f})
31664 The config file to use. To learn about its syntax, run @samp{man
31667 @item @code{enable-samba?} (default: @code{#f})
31668 Enable the @code{samba} daemon.
31670 @item @code{enable-smbd?} (default: @code{#f})
31671 Enable the @code{smbd} daemon.
31673 @item @code{enable-nmbd?} (default: @code{#f})
31674 Enable the @code{nmbd} daemon.
31676 @item @code{enable-winbindd?} (default: @code{#f})
31677 Enable the @code{winbindd} daemon.
31682 @cindex wsdd, Web service discovery daemon
31683 @subsubheading Web Service Discovery Daemon
31685 The @acronym{WSDD, Web Service Discovery daemon} implements the
31686 @uref{http://docs.oasis-open.org/ws-dd/discovery/1.1/os/wsdd-discovery-1.1-spec-os.html,
31687 Web Services Dynamic Discovery} protocol that enables host discovery
31688 over Multicast DNS, similar to what Avahi does. It is a drop-in
31689 replacement for SMB hosts that have had SMBv1 disabled for security
31692 @defvr {Scheme Variable} wsdd-service-type
31693 Service type for the WSD host daemon. The value for
31694 this service type is a @code{wsdd-configuration} record. The details
31695 for the @code{wsdd-configuration} record type are given below.
31698 @deftp {Data Type} wsdd-configuration
31699 This data type represents the configuration for the wsdd service.
31703 @item @code{package} (default: @code{wsdd})
31704 The wsdd package to use.
31706 @item @code{ipv4only?} (default: @code{#f})
31707 Only listen to IPv4 addresses.
31709 @item @code{ipv6only} (default: @code{#f})
31710 Only listen to IPv6 addresses. Please note: Activating both options is
31711 not possible, since there would be no IP versions to listen to.
31713 @item @code{chroot} (default: @code{#f})
31714 Chroot into a separate directory to prevent access to other directories.
31715 This is to increase security in case there is a vulnerability in
31718 @item @code{hop-limit} (default: @code{1})
31719 Limit to the level of hops for multicast packets. The default is
31720 @var{1} which should prevent packets from leaving the local network.
31722 @item @code{interface} (default: @code{'()})
31723 Limit to the given list of interfaces to listen to. By default wsdd
31724 will listen to all interfaces. Except the loopback interface is never
31727 @item @code{uuid-device} (default: @code{#f})
31728 The WSD protocol requires a device to have a UUID. Set this to manually
31729 assign the service a UUID.
31731 @item @code{domain} (default: @code{#f})
31732 Notify this host is a member of an Active Directory.
31734 @item @code{host-name} (default: @code{#f})
31735 Manually set the hostname rather than letting @command{wsdd} inherit
31736 this host's hostname. Only the host name part of a possible FQDN will
31737 be used in the default case.
31739 @item @code{preserve-case?} (default: @code{#f})
31740 By default @command{wsdd} will convert the hostname in workgroup to all
31741 uppercase. The opposite is true for hostnames in domains. Setting this
31742 parameter will preserve case.
31744 @item @code{workgroup} (default: @var{"WORKGROUP"})
31745 Change the name of the workgroup. By default @command{wsdd} reports
31746 this host being member of a workgroup.
31751 @node Continuous Integration
31752 @subsection Continuous Integration
31754 @cindex continuous integration
31755 @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
31756 integration tool for Guix. It can be used both for development and for
31757 providing substitutes to others (@pxref{Substitutes}).
31759 The @code{(gnu services cuirass)} module provides the following service.
31761 @defvr {Scheme Procedure} cuirass-service-type
31762 The type of the Cuirass service. Its value must be a
31763 @code{cuirass-configuration} object, as described below.
31766 To add build jobs, you have to set the @code{specifications} field of
31767 the configuration. For instance, the following example will build all
31768 the packages provided by the @code{my-channel} channel.
31771 (define %cuirass-specs
31772 #~(list (specification
31773 (name "my-channel")
31774 (build '(channels my-channel))
31778 (url "https://my-channel.git"))
31779 %default-channels)))))
31781 (service cuirass-service-type
31782 (cuirass-configuration
31783 (specifications %cuirass-specs)))
31786 To build the @code{linux-libre} package defined by the default Guix
31787 channel, one can use the following configuration.
31790 (define %cuirass-specs
31791 #~(list (specification
31793 (build '(packages "linux-libre")))))
31795 (service cuirass-service-type
31796 (cuirass-configuration
31797 (specifications %cuirass-specs)))
31800 The other configuration possibilities, as well as the specification
31801 record itself are described in the Cuirass manual
31802 (@pxref{Specifications,,, cuirass, Cuirass}).
31804 While information related to build jobs is located directly in the
31805 specifications, global settings for the @command{cuirass} process are
31806 accessible in other @code{cuirass-configuration} fields.
31808 @deftp {Data Type} cuirass-configuration
31809 Data type representing the configuration of Cuirass.
31812 @item @code{cuirass} (default: @code{cuirass})
31813 The Cuirass package to use.
31815 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
31816 Location of the log file.
31818 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
31819 Location of the log file used by the web interface.
31821 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
31822 Location of the repository cache.
31824 @item @code{user} (default: @code{"cuirass"})
31825 Owner of the @code{cuirass} process.
31827 @item @code{group} (default: @code{"cuirass"})
31828 Owner's group of the @code{cuirass} process.
31830 @item @code{interval} (default: @code{60})
31831 Number of seconds between the poll of the repositories followed by the
31834 @item @code{parameters} (default: @code{#f})
31835 Read parameters from the given @var{parameters} file. The supported
31836 parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
31838 @item @code{remote-server} (default: @code{#f})
31839 A @code{cuirass-remote-server-configuration} record to use the build
31840 remote mechanism or @code{#f} to use the default build mechanism.
31842 @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
31843 Use @var{database} as the database containing the jobs and the past
31844 build results. Since Cuirass uses PostgreSQL as a database engine,
31845 @var{database} must be a string such as @code{"dbname=cuirass
31848 @item @code{port} (default: @code{8081})
31849 Port number used by the HTTP server.
31851 @item @code{host} (default: @code{"localhost"})
31852 Listen on the network interface for @var{host}. The default is to
31853 accept connections from localhost.
31855 @item @code{specifications} (default: @code{#~'()})
31856 A gexp (@pxref{G-Expressions}) that evaluates to a list of
31857 specifications records. The specification record is described in the
31858 Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
31860 @item @code{use-substitutes?} (default: @code{#f})
31861 This allows using substitutes to avoid building every dependencies of a job
31864 @item @code{one-shot?} (default: @code{#f})
31865 Only evaluate specifications and build derivations once.
31867 @item @code{fallback?} (default: @code{#f})
31868 When substituting a pre-built binary fails, fall back to building
31871 @item @code{extra-options} (default: @code{'()})
31872 Extra options to pass when running the Cuirass processes.
31877 @cindex remote build
31878 @subsubheading Cuirass remote building
31880 Cuirass supports two mechanisms to build derivations.
31883 @item Using the local Guix daemon.
31884 This is the default build mechanism. Once the build jobs are
31885 evaluated, they are sent to the local Guix daemon. Cuirass then
31886 listens to the Guix daemon output to detect the various build events.
31888 @item Using the remote build mechanism.
31889 The build jobs are not submitted to the local Guix daemon. Instead, a
31890 remote server dispatches build requests to the connect remote workers,
31891 according to the build priorities.
31895 To enable this build mode a @code{cuirass-remote-server-configuration}
31896 record must be passed as @code{remote-server} argument of the
31897 @code{cuirass-configuration} record. The
31898 @code{cuirass-remote-server-configuration} record is described below.
31900 This build mode scales way better than the default build mode. This is
31901 the build mode that is used on the GNU Guix build farm at
31902 @url{https://ci.guix.gnu.org}. It should be preferred when using
31903 Cuirass to build large amount of packages.
31905 @deftp {Data Type} cuirass-remote-server-configuration
31906 Data type representing the configuration of the Cuirass remote-server.
31909 @item @code{backend-port} (default: @code{5555})
31910 The TCP port for communicating with @code{remote-worker} processes
31911 using ZMQ. It defaults to @code{5555}.
31913 @item @code{log-port} (default: @code{5556})
31914 The TCP port of the log server. It defaults to @code{5556}.
31916 @item @code{publish-port} (default: @code{5557})
31917 The TCP port of the publish server. It defaults to @code{5557}.
31919 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
31920 Location of the log file.
31922 @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
31923 Use @var{cache} directory to cache build log files.
31925 @item @code{trigger-url} (default: @code{#f})
31926 Once a substitute is successfully fetched, trigger substitute baking at
31929 @item @code{publish?} (default: @code{#t})
31930 If set to false, do not start a publish server and ignore the
31931 @code{publish-port} argument. This can be useful if there is already a
31932 standalone publish server standing next to the remote server.
31934 @item @code{public-key}
31935 @item @code{private-key}
31936 Use the specific @var{file}s as the public/private key pair used to sign
31937 the store items being published.
31942 At least one remote worker must also be started on any machine of the
31943 local network to actually perform the builds and report their status.
31945 @deftp {Data Type} cuirass-remote-worker-configuration
31946 Data type representing the configuration of the Cuirass remote-worker.
31949 @item @code{cuirass} (default: @code{cuirass})
31950 The Cuirass package to use.
31952 @item @code{workers} (default: @code{1})
31953 Start @var{workers} parallel workers.
31955 @item @code{server} (default: @code{#f})
31956 Do not use Avahi discovery and connect to the given @code{server} IP
31959 @item @code{systems} (default: @code{(list (%current-system))})
31960 Only request builds for the given @var{systems}.
31962 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
31963 Location of the log file.
31965 @item @code{publish-port} (default: @code{5558})
31966 The TCP port of the publish server. It defaults to @code{5558}.
31968 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
31969 The list of URLs where to look for substitutes by default.
31971 @item @code{public-key}
31972 @item @code{private-key}
31973 Use the specific @var{file}s as the public/private key pair used to sign
31974 the store items being published.
31979 @subsubheading Laminar
31981 @uref{https://laminar.ohwg.net/, Laminar} is a lightweight and modular
31982 Continuous Integration service. It doesn't have a configuration web UI
31983 instead uses version-controllable configuration files and scripts.
31985 Laminar encourages the use of existing tools such as bash and cron
31986 instead of reinventing them.
31988 @defvr {Scheme Procedure} laminar-service-type
31989 The type of the Laminar service. Its value must be a
31990 @code{laminar-configuration} object, as described below.
31992 All configuration values have defaults, a minimal configuration to get
31993 Laminar running is shown below. By default, the web interface is
31994 available on port 8080.
31997 (service laminar-service-type)
32001 @deftp {Data Type} laminar-configuration
32002 Data type representing the configuration of Laminar.
32005 @item @code{laminar} (default: @code{laminar})
32006 The Laminar package to use.
32008 @item @code{home-directory} (default: @code{"/var/lib/laminar"})
32009 The directory for job configurations and run directories.
32011 @item @code{bind-http} (default: @code{"*:8080"})
32012 The interface/port or unix socket on which laminard should listen for
32013 incoming connections to the web frontend.
32015 @item @code{bind-rpc} (default: @code{"unix-abstract:laminar"})
32016 The interface/port or unix socket on which laminard should listen for
32017 incoming commands such as build triggers.
32019 @item @code{title} (default: @code{"Laminar"})
32020 The page title to show in the web frontend.
32022 @item @code{keep-rundirs} (default: @code{0})
32023 Set to an integer defining how many rundirs to keep per job. The
32024 lowest-numbered ones will be deleted. The default is 0, meaning all run
32025 dirs will be immediately deleted.
32027 @item @code{archive-url} (default: @code{#f})
32028 The web frontend served by laminard will use this URL to form links to
32029 artefacts archived jobs.
32031 @item @code{base-url} (default: @code{#f})
32032 Base URL to use for links to laminar itself.
32037 @node Power Management Services
32038 @subsection Power Management Services
32041 @cindex power management with TLP
32042 @subsubheading TLP daemon
32044 The @code{(gnu services pm)} module provides a Guix service definition
32045 for the Linux power management tool TLP.
32047 TLP enables various powersaving modes in userspace and kernel.
32048 Contrary to @code{upower-service}, it is not a passive,
32049 monitoring tool, as it will apply custom settings each time a new power
32050 source is detected. More information can be found at
32051 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
32053 @deffn {Scheme Variable} tlp-service-type
32054 The service type for the TLP tool. The default settings are optimised
32055 for battery life on most systems, but you can tweak them to your heart's
32056 content by adding a valid @code{tlp-configuration}:
32058 (service tlp-service-type
32060 (cpu-scaling-governor-on-ac (list "performance"))
32061 (sched-powersave-on-bat? #t)))
32065 Each parameter definition is preceded by its type; for example,
32066 @samp{boolean foo} indicates that the @code{foo} parameter should be
32067 specified as a boolean. Types starting with @code{maybe-} denote
32068 parameters that won't show up in TLP config file when their value is
32069 left unset, or is explicitly set to the @code{%unset-value} value.
32071 @c The following documentation was initially generated by
32072 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
32073 @c documentation is better, so we shouldn't hesitate to edit below as
32074 @c needed. However if the change you want to make to this documentation
32075 @c can be done in an automated way, it's probably easier to change
32076 @c (generate-documentation) than to make it below and have to deal with
32077 @c the churn as TLP updates.
32079 Available @code{tlp-configuration} fields are:
32081 @deftypevr {@code{tlp-configuration} parameter} package tlp
32086 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
32087 Set to true if you wish to enable TLP.
32089 Defaults to @samp{#t}.
32093 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
32094 Default mode when no power supply can be detected. Alternatives are AC
32097 Defaults to @samp{"AC"}.
32101 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
32102 Number of seconds Linux kernel has to wait after the disk goes idle,
32103 before syncing on AC.
32105 Defaults to @samp{0}.
32109 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
32110 Same as @code{disk-idle-ac} but on BAT mode.
32112 Defaults to @samp{2}.
32116 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
32117 Dirty pages flushing periodicity, expressed in seconds.
32119 Defaults to @samp{15}.
32123 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
32124 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
32126 Defaults to @samp{60}.
32130 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
32131 CPU frequency scaling governor on AC mode. With intel_pstate driver,
32132 alternatives are powersave and performance. With acpi-cpufreq driver,
32133 alternatives are ondemand, powersave, performance and conservative.
32135 Defaults to @samp{disabled}.
32139 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
32140 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
32142 Defaults to @samp{disabled}.
32146 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
32147 Set the min available frequency for the scaling governor on AC.
32149 Defaults to @samp{disabled}.
32153 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
32154 Set the max available frequency for the scaling governor on AC.
32156 Defaults to @samp{disabled}.
32160 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
32161 Set the min available frequency for the scaling governor on BAT.
32163 Defaults to @samp{disabled}.
32167 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
32168 Set the max available frequency for the scaling governor on BAT.
32170 Defaults to @samp{disabled}.
32174 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
32175 Limit the min P-state to control the power dissipation of the CPU, in AC
32176 mode. Values are stated as a percentage of the available performance.
32178 Defaults to @samp{disabled}.
32182 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
32183 Limit the max P-state to control the power dissipation of the CPU, in AC
32184 mode. Values are stated as a percentage of the available performance.
32186 Defaults to @samp{disabled}.
32190 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
32191 Same as @code{cpu-min-perf-on-ac} on BAT mode.
32193 Defaults to @samp{disabled}.
32197 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
32198 Same as @code{cpu-max-perf-on-ac} on BAT mode.
32200 Defaults to @samp{disabled}.
32204 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
32205 Enable CPU turbo boost feature on AC mode.
32207 Defaults to @samp{disabled}.
32211 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
32212 Same as @code{cpu-boost-on-ac?} on BAT mode.
32214 Defaults to @samp{disabled}.
32218 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
32219 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
32220 used under light load conditions.
32222 Defaults to @samp{#f}.
32226 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
32227 Same as @code{sched-powersave-on-ac?} but on BAT mode.
32229 Defaults to @samp{#t}.
32233 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
32234 Enable Linux kernel NMI watchdog.
32236 Defaults to @samp{#f}.
32240 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
32241 For Linux kernels with PHC patch applied, change CPU voltages. An
32242 example value would be @samp{"F:V F:V F:V F:V"}.
32244 Defaults to @samp{disabled}.
32248 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
32249 Set CPU performance versus energy saving policy on AC@. Alternatives are
32250 performance, normal, powersave.
32252 Defaults to @samp{"performance"}.
32256 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
32257 Same as @code{energy-perf-policy-ac} but on BAT mode.
32259 Defaults to @samp{"powersave"}.
32263 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
32268 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
32269 Hard disk advanced power management level.
32273 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
32274 Same as @code{disk-apm-bat} but on BAT mode.
32278 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
32279 Hard disk spin down timeout. One value has to be specified for each
32280 declared hard disk.
32282 Defaults to @samp{disabled}.
32286 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
32287 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
32289 Defaults to @samp{disabled}.
32293 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
32294 Select IO scheduler for disk devices. One value has to be specified for
32295 each declared hard disk. Example alternatives are cfq, deadline and
32298 Defaults to @samp{disabled}.
32302 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
32303 SATA aggressive link power management (ALPM) level. Alternatives are
32304 min_power, medium_power, max_performance.
32306 Defaults to @samp{"max_performance"}.
32310 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
32311 Same as @code{sata-linkpwr-ac} but on BAT mode.
32313 Defaults to @samp{"min_power"}.
32317 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
32318 Exclude specified SATA host devices for link power management.
32320 Defaults to @samp{disabled}.
32324 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
32325 Enable Runtime Power Management for AHCI controller and disks on AC
32328 Defaults to @samp{disabled}.
32332 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
32333 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
32335 Defaults to @samp{disabled}.
32339 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
32340 Seconds of inactivity before disk is suspended.
32342 Defaults to @samp{15}.
32346 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
32347 PCI Express Active State Power Management level. Alternatives are
32348 default, performance, powersave.
32350 Defaults to @samp{"performance"}.
32354 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
32355 Same as @code{pcie-aspm-ac} but on BAT mode.
32357 Defaults to @samp{"powersave"}.
32361 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer start-charge-thresh-bat0
32362 Percentage when battery 0 should begin charging. Only supported on some laptops.
32364 Defaults to @samp{disabled}.
32368 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer stop-charge-thresh-bat0
32369 Percentage when battery 0 should stop charging. Only supported on some laptops.
32371 Defaults to @samp{disabled}.
32375 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer start-charge-thresh-bat1
32376 Percentage when battery 1 should begin charging. Only supported on some laptops.
32378 Defaults to @samp{disabled}.
32382 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer stop-charge-thresh-bat1
32383 Percentage when battery 1 should stop charging. Only supported on some laptops.
32385 Defaults to @samp{disabled}.
32389 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
32390 Radeon graphics clock speed level. Alternatives are low, mid, high,
32393 Defaults to @samp{"high"}.
32397 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
32398 Same as @code{radeon-power-ac} but on BAT mode.
32400 Defaults to @samp{"low"}.
32404 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
32405 Radeon dynamic power management method (DPM). Alternatives are battery,
32408 Defaults to @samp{"performance"}.
32412 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
32413 Same as @code{radeon-dpm-state-ac} but on BAT mode.
32415 Defaults to @samp{"battery"}.
32419 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
32420 Radeon DPM performance level. Alternatives are auto, low, high.
32422 Defaults to @samp{"auto"}.
32426 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
32427 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
32429 Defaults to @samp{"auto"}.
32433 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
32434 Wifi power saving mode.
32436 Defaults to @samp{#f}.
32440 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
32441 Same as @code{wifi-power-ac?} but on BAT mode.
32443 Defaults to @samp{#t}.
32447 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
32448 Disable wake on LAN.
32450 Defaults to @samp{#t}.
32454 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
32455 Timeout duration in seconds before activating audio power saving on
32456 Intel HDA and AC97 devices. A value of 0 disables power saving.
32458 Defaults to @samp{0}.
32462 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
32463 Same as @code{sound-powersave-ac} but on BAT mode.
32465 Defaults to @samp{1}.
32469 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
32470 Disable controller in powersaving mode on Intel HDA devices.
32472 Defaults to @samp{#t}.
32476 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
32477 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
32478 powered on again by releasing (and reinserting) the eject lever or by
32479 pressing the disc eject button on newer models.
32481 Defaults to @samp{#f}.
32485 @deftypevr {@code{tlp-configuration} parameter} string bay-device
32486 Name of the optical drive device to power off.
32488 Defaults to @samp{"sr0"}.
32492 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
32493 Runtime Power Management for PCI(e) bus devices. Alternatives are on
32496 Defaults to @samp{"on"}.
32500 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
32501 Same as @code{runtime-pm-ac} but on BAT mode.
32503 Defaults to @samp{"auto"}.
32507 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
32508 Runtime Power Management for all PCI(e) bus devices, except blacklisted
32511 Defaults to @samp{#t}.
32515 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
32516 Exclude specified PCI(e) device addresses from Runtime Power Management.
32518 Defaults to @samp{disabled}.
32522 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
32523 Exclude PCI(e) devices assigned to the specified drivers from Runtime
32528 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
32529 Enable USB autosuspend feature.
32531 Defaults to @samp{#t}.
32535 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
32536 Exclude specified devices from USB autosuspend.
32538 Defaults to @samp{disabled}.
32542 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
32543 Exclude WWAN devices from USB autosuspend.
32545 Defaults to @samp{#t}.
32549 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
32550 Include specified devices into USB autosuspend, even if they are already
32551 excluded by the driver or via @code{usb-blacklist-wwan?}.
32553 Defaults to @samp{disabled}.
32557 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
32558 Enable USB autosuspend before shutdown.
32560 Defaults to @samp{disabled}.
32564 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
32565 Restore radio device state (bluetooth, wifi, wwan) from previous
32566 shutdown on system startup.
32568 Defaults to @samp{#f}.
32573 @cindex CPU frequency scaling with thermald
32574 @subsubheading Thermald daemon
32576 The @code{(gnu services pm)} module provides an interface to
32577 thermald, a CPU frequency scaling service which helps prevent overheating.
32579 @defvr {Scheme Variable} thermald-service-type
32580 This is the service type for
32581 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
32582 Thermal Daemon, which is responsible for controlling the thermal state
32583 of processors and preventing overheating.
32586 @deftp {Data Type} thermald-configuration
32587 Data type representing the configuration of @code{thermald-service-type}.
32590 @item @code{adaptive?} (default: @code{#f})
32591 Use @acronym{DPTF, Dynamic Power and Thermal Framework} adaptive tables
32594 @item @code{ignore-cpuid-check?} (default: @code{#f})
32595 Ignore cpuid check for supported CPU models.
32597 @item @code{thermald} (default: @var{thermald})
32598 Package object of thermald.
32603 @node Audio Services
32604 @subsection Audio Services
32606 The @code{(gnu services audio)} module provides a service to start MPD
32607 (the Music Player Daemon).
32610 @subsubheading Music Player Daemon
32612 The Music Player Daemon (MPD) is a service that can play music while
32613 being controlled from the local machine or over the network by a variety
32616 The following example shows how one might run @code{mpd} as user
32617 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
32620 (service mpd-service-type
32626 @defvr {Scheme Variable} mpd-service-type
32627 The service type for @command{mpd}
32630 @deftp {Data Type} mpd-configuration
32631 Data type representing the configuration of @command{mpd}.
32634 @item @code{user} (default: @code{"mpd"})
32635 The user to run mpd as.
32637 @item @code{music-dir} (default: @code{"~/Music"})
32638 The directory to scan for music files.
32640 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
32641 The directory to store playlists.
32643 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
32644 The location of the music database.
32646 @item @code{state-file} (default: @code{"~/.mpd/state"})
32647 The location of the file that stores current MPD's state.
32649 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
32650 The location of the sticker database.
32652 @item @code{port} (default: @code{"6600"})
32653 The port to run mpd on.
32655 @item @code{address} (default: @code{"any"})
32656 The address that mpd will bind to. To use a Unix domain socket,
32657 an absolute path can be specified here.
32659 @item @code{outputs} (default: @code{"(list (mpd-output))"})
32660 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
32665 @deftp {Data Type} mpd-output
32666 Data type representing an @command{mpd} audio output.
32669 @item @code{name} (default: @code{"MPD"})
32670 The name of the audio output.
32672 @item @code{type} (default: @code{"pulse"})
32673 The type of audio output.
32675 @item @code{enabled?} (default: @code{#t})
32676 Specifies whether this audio output is enabled when MPD is started. By
32677 default, all audio outputs are enabled. This is just the default
32678 setting when there is no state file; with a state file, the previous
32681 @item @code{tags?} (default: @code{#t})
32682 If set to @code{#f}, then MPD will not send tags to this output. This
32683 is only useful for output plugins that can receive tags, for example the
32684 @code{httpd} output plugin.
32686 @item @code{always-on?} (default: @code{#f})
32687 If set to @code{#t}, then MPD attempts to keep this audio output always
32688 open. This may be useful for streaming servers, when you don’t want to
32689 disconnect all listeners even when playback is accidentally stopped.
32691 @item @code{mixer-type}
32692 This field accepts a symbol that specifies which mixer should be used
32693 for this audio output: the @code{hardware} mixer, the @code{software}
32694 mixer, the @code{null} mixer (allows setting the volume, but with no
32695 effect; this can be used as a trick to implement an external mixer
32696 External Mixer) or no mixer (@code{none}).
32698 @item @code{extra-options} (default: @code{'()})
32699 An association list of option symbols to string values to be appended to
32700 the audio output configuration.
32705 The following example shows a configuration of @code{mpd} that provides
32706 an HTTP audio streaming output.
32709 (service mpd-service-type
32717 `((encoder . "vorbis")
32718 (port . "8080"))))))))
32722 @node Virtualization Services
32723 @subsection Virtualization Services
32725 The @code{(gnu services virtualization)} module provides services for
32726 the libvirt and virtlog daemons, as well as other virtualization-related
32729 @subsubheading Libvirt daemon
32731 @code{libvirtd} is the server side daemon component of the libvirt
32732 virtualization management system. This daemon runs on host servers
32733 and performs required management tasks for virtualized guests.
32735 @deffn {Scheme Variable} libvirt-service-type
32736 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
32737 Its value must be a @code{libvirt-configuration}.
32740 (service libvirt-service-type
32741 (libvirt-configuration
32742 (unix-sock-group "libvirt")
32743 (tls-port "16555")))
32747 @c Auto-generated with (generate-libvirt-documentation)
32748 Available @code{libvirt-configuration} fields are:
32750 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
32755 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
32756 Flag listening for secure TLS connections on the public TCP/IP port.
32757 You must set @code{listen} for this to have any effect.
32759 It is necessary to setup a CA and issue server certificates before using
32762 Defaults to @samp{#t}.
32766 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
32767 Listen for unencrypted TCP connections on the public TCP/IP port. You must
32768 set @code{listen} for this to have any effect.
32770 Using the TCP socket requires SASL authentication by default. Only SASL
32771 mechanisms which support data encryption are allowed. This is
32772 DIGEST_MD5 and GSSAPI (Kerberos5).
32774 Defaults to @samp{#f}.
32778 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
32779 Port for accepting secure TLS connections. This can be a port number,
32782 Defaults to @samp{"16514"}.
32786 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
32787 Port for accepting insecure TCP connections. This can be a port number,
32790 Defaults to @samp{"16509"}.
32794 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
32795 IP address or hostname used for client connections.
32797 Defaults to @samp{"0.0.0.0"}.
32801 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
32802 Flag toggling mDNS advertisement of the libvirt service.
32804 Alternatively can disable for all services on a host by stopping the
32807 Defaults to @samp{#f}.
32811 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
32812 Default mDNS advertisement name. This must be unique on the immediate
32815 Defaults to @samp{"Virtualization Host <hostname>"}.
32819 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
32820 UNIX domain socket group ownership. This can be used to allow a
32821 'trusted' set of users access to management capabilities without
32824 Defaults to @samp{"root"}.
32828 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
32829 UNIX socket permissions for the R/O socket. This is used for monitoring
32832 Defaults to @samp{"0777"}.
32836 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
32837 UNIX socket permissions for the R/W socket. Default allows only root.
32838 If PolicyKit is enabled on the socket, the default will change to allow
32839 everyone (eg, 0777)
32841 Defaults to @samp{"0770"}.
32845 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
32846 UNIX socket permissions for the admin socket. Default allows only owner
32847 (root), do not change it unless you are sure to whom you are exposing
32850 Defaults to @samp{"0777"}.
32854 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
32855 The directory in which sockets will be found/created.
32857 Defaults to @samp{"/var/run/libvirt"}.
32861 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
32862 Authentication scheme for UNIX read-only sockets. By default socket
32863 permissions allow anyone to connect
32865 Defaults to @samp{"polkit"}.
32869 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
32870 Authentication scheme for UNIX read-write sockets. By default socket
32871 permissions only allow root. If PolicyKit support was compiled into
32872 libvirt, the default will be to use 'polkit' auth.
32874 Defaults to @samp{"polkit"}.
32878 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
32879 Authentication scheme for TCP sockets. If you don't enable SASL, then
32880 all TCP traffic is cleartext. Don't do this outside of a dev/test
32883 Defaults to @samp{"sasl"}.
32887 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
32888 Authentication scheme for TLS sockets. TLS sockets already have
32889 encryption provided by the TLS layer, and limited authentication is done
32892 It is possible to make use of any SASL authentication mechanism as well,
32893 by using 'sasl' for this option
32895 Defaults to @samp{"none"}.
32899 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
32900 API access control scheme.
32902 By default an authenticated user is allowed access to all APIs. Access
32903 drivers can place restrictions on this.
32905 Defaults to @samp{()}.
32909 @deftypevr {@code{libvirt-configuration} parameter} string key-file
32910 Server key file path. If set to an empty string, then no private key is
32913 Defaults to @samp{""}.
32917 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
32918 Server key file path. If set to an empty string, then no certificate is
32921 Defaults to @samp{""}.
32925 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
32926 Server key file path. If set to an empty string, then no CA certificate
32929 Defaults to @samp{""}.
32933 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
32934 Certificate revocation list path. If set to an empty string, then no
32937 Defaults to @samp{""}.
32941 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
32942 Disable verification of our own server certificates.
32944 When libvirtd starts it performs some sanity checks against its own
32947 Defaults to @samp{#f}.
32951 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
32952 Disable verification of client certificates.
32954 Client certificate verification is the primary authentication mechanism.
32955 Any client which does not present a certificate signed by the CA will be
32958 Defaults to @samp{#f}.
32962 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
32963 Whitelist of allowed x509 Distinguished Name.
32965 Defaults to @samp{()}.
32969 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
32970 Whitelist of allowed SASL usernames. The format for username depends on
32971 the SASL authentication mechanism.
32973 Defaults to @samp{()}.
32977 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
32978 Override the compile time default TLS priority string. The default is
32979 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
32980 is desired for libvirt to deviate from the global default settings.
32982 Defaults to @samp{"NORMAL"}.
32986 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
32987 Maximum number of concurrent client connections to allow over all
32990 Defaults to @samp{5000}.
32994 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
32995 Maximum length of queue of connections waiting to be accepted by the
32996 daemon. Note, that some protocols supporting retransmission may obey
32997 this so that a later reattempt at connection succeeds.
32999 Defaults to @samp{1000}.
33003 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
33004 Maximum length of queue of accepted but not yet authenticated clients.
33005 Set this to zero to turn this feature off
33007 Defaults to @samp{20}.
33011 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
33012 Number of workers to start up initially.
33014 Defaults to @samp{5}.
33018 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
33019 Maximum number of worker threads.
33021 If the number of active clients exceeds @code{min-workers}, then more
33022 threads are spawned, up to max_workers limit. Typically you'd want
33023 max_workers to equal maximum number of clients allowed.
33025 Defaults to @samp{20}.
33029 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
33030 Number of priority workers. If all workers from above pool are stuck,
33031 some calls marked as high priority (notably domainDestroy) can be
33032 executed in this pool.
33034 Defaults to @samp{5}.
33038 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
33039 Total global limit on concurrent RPC calls.
33041 Defaults to @samp{20}.
33045 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
33046 Limit on concurrent requests from a single client connection. To avoid
33047 one client monopolizing the server this should be a small fraction of
33048 the global max_requests and max_workers parameter.
33050 Defaults to @samp{5}.
33054 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
33055 Same as @code{min-workers} but for the admin interface.
33057 Defaults to @samp{1}.
33061 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
33062 Same as @code{max-workers} but for the admin interface.
33064 Defaults to @samp{5}.
33068 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
33069 Same as @code{max-clients} but for the admin interface.
33071 Defaults to @samp{5}.
33075 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
33076 Same as @code{max-queued-clients} but for the admin interface.
33078 Defaults to @samp{5}.
33082 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
33083 Same as @code{max-client-requests} but for the admin interface.
33085 Defaults to @samp{5}.
33089 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
33090 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
33092 Defaults to @samp{3}.
33096 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
33099 A filter allows to select a different logging level for a given category
33100 of logs. The format for a filter is one of:
33111 where @code{name} is a string which is matched against the category
33112 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
33113 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
33114 name in the filter can be a substring of the full category name, in
33115 order to match multiple similar categories), the optional @samp{"+"}
33116 prefix tells libvirt to log stack trace for each message matching name,
33117 and @code{x} is the minimal level where matching messages should be
33135 Multiple filters can be defined in a single filters statement, they just
33136 need to be separated by spaces.
33138 Defaults to @samp{"3:remote 4:event"}.
33142 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
33145 An output is one of the places to save logging information. The format
33146 for an output can be:
33150 output goes to stderr
33152 @item x:syslog:name
33153 use syslog for the output and use the given name as the ident
33155 @item x:file:file_path
33156 output to a file, with the given filepath
33159 output to journald logging system
33163 In all case the x prefix is the minimal level, acting as a filter
33180 Multiple outputs can be defined, they just need to be separated by
33183 Defaults to @samp{"3:stderr"}.
33187 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
33188 Allows usage of the auditing subsystem to be altered
33192 0: disable all auditing
33195 1: enable auditing, only if enabled on host
33198 2: enable auditing, and exit if disabled on host.
33202 Defaults to @samp{1}.
33206 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
33207 Send audit messages via libvirt logging infrastructure.
33209 Defaults to @samp{#f}.
33213 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
33214 Host UUID@. UUID must not have all digits be the same.
33216 Defaults to @samp{""}.
33220 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
33221 Source to read host UUID.
33225 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
33228 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
33232 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
33235 Defaults to @samp{"smbios"}.
33239 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
33240 A keepalive message is sent to a client after @code{keepalive_interval}
33241 seconds of inactivity to check if the client is still responding. If
33242 set to -1, libvirtd will never send keepalive requests; however clients
33243 can still send them and the daemon will send responses.
33245 Defaults to @samp{5}.
33249 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
33250 Maximum number of keepalive messages that are allowed to be sent to the
33251 client without getting any response before the connection is considered
33254 In other words, the connection is automatically closed approximately
33255 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
33256 the last message received from the client. When @code{keepalive-count}
33257 is set to 0, connections will be automatically closed after
33258 @code{keepalive-interval} seconds of inactivity without sending any
33259 keepalive messages.
33261 Defaults to @samp{5}.
33265 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
33266 Same as above but for admin interface.
33268 Defaults to @samp{5}.
33272 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
33273 Same as above but for admin interface.
33275 Defaults to @samp{5}.
33279 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
33280 Timeout for Open vSwitch calls.
33282 The @code{ovs-vsctl} utility is used for the configuration and its
33283 timeout option is set by default to 5 seconds to avoid potential
33284 infinite waits blocking libvirt.
33286 Defaults to @samp{5}.
33290 @c %end of autogenerated docs
33292 @subsubheading Virtlog daemon
33293 The virtlogd service is a server side daemon component of libvirt that is
33294 used to manage logs from virtual machine consoles.
33296 This daemon is not used directly by libvirt client applications, rather it
33297 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
33298 standalone daemon, the main @code{libvirtd} daemon can be restarted without
33299 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
33300 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
33302 @deffn {Scheme Variable} virtlog-service-type
33303 This is the type of the virtlog daemon.
33304 Its value must be a @code{virtlog-configuration}.
33307 (service virtlog-service-type
33308 (virtlog-configuration
33309 (max-clients 1000)))
33313 @deftypevar {@code{libvirt} parameter} package libvirt
33317 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
33318 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
33320 Defaults to @samp{3}.
33324 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
33327 A filter allows to select a different logging level for a given category
33328 of logs The format for a filter is one of:
33339 where @code{name} is a string which is matched against the category
33340 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
33341 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
33342 be a substring of the full category name, in order to match multiple
33343 similar categories), the optional "+" prefix tells libvirt to log stack
33344 trace for each message matching name, and @code{x} is the minimal level
33345 where matching messages should be logged:
33362 Multiple filters can be defined in a single filters statement, they just
33363 need to be separated by spaces.
33365 Defaults to @samp{"3:remote 4:event"}.
33369 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
33372 An output is one of the places to save logging information The format
33373 for an output can be:
33377 output goes to stderr
33379 @item x:syslog:name
33380 use syslog for the output and use the given name as the ident
33382 @item x:file:file_path
33383 output to a file, with the given filepath
33386 output to journald logging system
33390 In all case the x prefix is the minimal level, acting as a filter
33407 Multiple outputs can be defined, they just need to be separated by
33410 Defaults to @samp{"3:stderr"}.
33414 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
33415 Maximum number of concurrent client connections to allow over all
33418 Defaults to @samp{1024}.
33422 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
33423 Maximum file size before rolling over.
33425 Defaults to @samp{2MB}
33429 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
33430 Maximum number of backup files to keep.
33432 Defaults to @samp{3}
33436 @anchor{transparent-emulation-qemu}
33437 @subsubheading Transparent Emulation with QEMU
33440 @cindex @code{binfmt_misc}
33441 @code{qemu-binfmt-service-type} provides support for transparent
33442 emulation of program binaries built for different architectures---e.g.,
33443 it allows you to transparently execute an ARMv7 program on an x86_64
33444 machine. It achieves this by combining the @uref{https://www.qemu.org,
33445 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
33446 This feature only allows you to emulate GNU/Linux on a different
33447 architecture, but see below for GNU/Hurd support.
33449 @defvr {Scheme Variable} qemu-binfmt-service-type
33450 This is the type of the QEMU/binfmt service for transparent emulation.
33451 Its value must be a @code{qemu-binfmt-configuration} object, which
33452 specifies the QEMU package to use as well as the architecture we want to
33456 (service qemu-binfmt-service-type
33457 (qemu-binfmt-configuration
33458 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
33461 In this example, we enable transparent emulation for the ARM and aarch64
33462 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
33463 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
33464 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
33467 @deftp {Data Type} qemu-binfmt-configuration
33468 This is the configuration for the @code{qemu-binfmt} service.
33471 @item @code{platforms} (default: @code{'()})
33472 The list of emulated QEMU platforms. Each item must be a @dfn{platform
33473 object} as returned by @code{lookup-qemu-platforms} (see below).
33475 For example, let's suppose you're on an x86_64 machine and you have this
33479 (service qemu-binfmt-service-type
33480 (qemu-binfmt-configuration
33481 (platforms (lookup-qemu-platforms "arm"))))
33487 guix build -s armhf-linux inkscape
33491 and it will build Inkscape for ARMv7 @emph{as if it were a native
33492 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
33493 if you'd like to test a package build for an architecture you don't have
33496 @item @code{qemu} (default: @code{qemu})
33497 The QEMU package to use.
33501 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
33502 Return the list of QEMU platform objects corresponding to
33503 @var{platforms}@dots{}. @var{platforms} must be a list of strings
33504 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
33505 @code{"mips64el"}, and so on.
33508 @deffn {Scheme Procedure} qemu-platform? @var{obj}
33509 Return true if @var{obj} is a platform object.
33512 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
33513 Return the name of @var{platform}---a string such as @code{"arm"}.
33517 @subsubheading QEMU Guest Agent
33521 The QEMU guest agent provides control over the emulated system to the
33522 host. The @code{qemu-guest-agent} service runs the agent on Guix
33523 guests. To control the agent from the host, open a socket by invoking
33524 QEMU with the following arguments:
33527 qemu-system-x86_64 \
33528 -chardev socket,path=/tmp/qga.sock,server=on,wait=off,id=qga0 \
33529 -device virtio-serial \
33530 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0 \
33534 This creates a socket at @file{/tmp/qga.sock} on the host. Once the
33535 guest agent is running, you can issue commands with @code{socat}:
33538 $ guix shell socat -- socat unix-connect:/tmp/qga.sock stdio
33539 @{"execute": "guest-get-host-name"@}
33540 @{"return": @{"host-name": "guix"@}@}
33543 See @url{https://wiki.qemu.org/Features/GuestAgent,QEMU guest agent
33544 documentation} for more options and commands.
33546 @defvr {Scheme Variable} qemu-guest-agent-service-type
33547 Service type for the QEMU guest agent service.
33550 @deftp {Data Type} qemu-guest-agent-configuration
33551 Configuration for the @code{qemu-guest-agent} service.
33554 @item @code{qemu} (default: @code{qemu-minimal})
33555 The QEMU package to use.
33557 @item @code{device} (default: @code{""})
33558 File name of the device or socket the agent uses to communicate with the
33559 host. If empty, QEMU uses a default file name.
33564 @subsubheading The Hurd in a Virtual Machine
33566 @cindex @code{hurd}
33570 Service @code{hurd-vm} provides support for running GNU/Hurd in a
33571 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
33572 to be used on GNU/Linux and the given GNU/Hurd operating system
33573 configuration is cross-compiled. The virtual machine is a Shepherd
33574 service that can be referred to by the names @code{hurd-vm} and
33575 @code{childhurd} and be controlled with commands such as:
33579 herd stop childhurd
33582 When the service is running, you can view its console by connecting to
33583 it with a VNC client, for example with:
33586 guix shell tigervnc-client -- vncviewer localhost:5900
33589 The default configuration (see @code{hurd-vm-configuration} below)
33590 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
33591 (the virtual machine emulator) redirects to port 10222 on the host.
33592 Thus, you can connect over SSH to the childhurd with:
33595 ssh root@@localhost -p 10022
33598 The childhurd is volatile and stateless: it starts with a fresh root
33599 file system every time you restart it. By default though, all the files
33600 under @file{/etc/childhurd} on the host are copied as is to the root
33601 file system of the childhurd when it boots. This allows you to
33602 initialize ``secrets'' inside the VM: SSH host keys, authorized
33603 substitute keys, and so on---see the explanation of @code{secret-root}
33606 @defvr {Scheme Variable} hurd-vm-service-type
33607 This is the type of the Hurd in a Virtual Machine service. Its value
33608 must be a @code{hurd-vm-configuration} object, which specifies the
33609 operating system (@pxref{operating-system Reference}) and the disk size
33610 for the Hurd Virtual Machine, the QEMU package to use as well as the
33611 options for running it.
33616 (service hurd-vm-service-type
33617 (hurd-vm-configuration
33618 (disk-size (* 5000 (expt 2 20))) ;5G
33619 (memory-size 1024))) ;1024MiB
33622 would create a disk image big enough to build GNU@tie{}Hello, with some
33626 @deftp {Data Type} hurd-vm-configuration
33627 The data type representing the configuration for
33628 @code{hurd-vm-service-type}.
33631 @item @code{os} (default: @var{%hurd-vm-operating-system})
33632 The operating system to instantiate. This default is bare-bones with a
33633 permissive OpenSSH secure shell daemon listening on port 2222
33634 (@pxref{Networking Services, @code{openssh-service-type}}).
33636 @item @code{qemu} (default: @code{qemu-minimal})
33637 The QEMU package to use.
33639 @item @code{image} (default: @var{hurd-vm-disk-image})
33640 The procedure used to build the disk-image built from this
33643 @item @code{disk-size} (default: @code{'guess})
33644 The size of the disk image.
33646 @item @code{memory-size} (default: @code{512})
33647 The memory size of the Virtual Machine in mebibytes.
33649 @item @code{options} (default: @code{'("--snapshot")})
33650 The extra options for running QEMU.
33652 @item @code{id} (default: @code{#f})
33653 If set, a non-zero positive integer used to parameterize Childhurd
33654 instances. It is appended to the service's name,
33655 e.g. @code{childhurd1}.
33657 @item @code{net-options} (default: @var{hurd-vm-net-options})
33658 The procedure used to produce the list of QEMU networking options.
33660 By default, it produces
33663 '("--device" "rtl8139,netdev=net0"
33664 "--netdev" (string-append
33666 "hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004,"
33667 "hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222,"
33668 "hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900"))
33671 with forwarded ports:
33674 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
33675 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
33676 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
33679 @item @code{secret-root} (default: @file{/etc/childhurd})
33680 The root directory with out-of-band secrets to be installed into the
33681 childhurd once it runs. Childhurds are volatile which means that on
33682 every startup, secrets such as the SSH host keys and Guix signing key
33685 If the @file{/etc/childhurd} directory does not exist, the
33686 @code{secret-service} running in the Childhurd will be sent an empty
33689 By default, the service automatically populates @file{/etc/childhurd}
33690 with the following non-volatile secrets, unless they already exist:
33693 /etc/childhurd/etc/guix/acl
33694 /etc/childhurd/etc/guix/signing-key.pub
33695 /etc/childhurd/etc/guix/signing-key.sec
33696 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
33697 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
33698 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
33699 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
33702 These files are automatically sent to the guest Hurd VM when it boots,
33703 including permissions.
33705 @cindex childhurd, offloading
33706 @cindex Hurd, offloading
33707 Having these files in place means that only a couple of things are
33708 missing to allow the host to offload @code{i586-gnu} builds to the
33713 Authorizing the childhurd's key on the host so that the host accepts
33714 build results coming from the childhurd, which can be done like so:
33717 guix archive --authorize < \
33718 /etc/childhurd/etc/guix/signing-key.pub
33722 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
33726 We're working towards making that happen automatically---get in touch
33727 with us at @email{guix-devel@@gnu.org} to discuss it!
33731 Note that by default the VM image is volatile, i.e., once stopped the
33732 contents are lost. If you want a stateful image instead, override the
33733 configuration's @code{image} and @code{options} without
33734 the @code{--snapshot} flag using something along these lines:
33737 (service hurd-vm-service-type
33738 (hurd-vm-configuration
33739 (image (const "/out/of/store/writable/hurd.img"))
33743 @subsubheading Ganeti
33748 This service is considered experimental. Configuration options may be changed
33749 in a backwards-incompatible manner, and not all features have been thorougly
33750 tested. Users of this service are encouraged to share their experience at
33751 @email{guix-devel@@gnu.org}.
33754 Ganeti is a virtual machine management system. It is designed to keep virtual
33755 machines running on a cluster of servers even in the event of hardware failures,
33756 and to make maintenance and recovery tasks easy. It consists of multiple
33757 services which are described later in this section. In addition to the Ganeti
33758 service, you will need the OpenSSH service (@pxref{Networking Services,
33759 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
33760 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
33761 and address (or use a DNS server).
33763 All nodes participating in a Ganeti cluster should have the same Ganeti and
33764 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
33765 cluster node that supports multiple storage backends, and installs the
33766 @code{debootstrap} and @code{guix} @dfn{OS providers}:
33769 (use-package-modules virtualization)
33770 (use-service-modules base ganeti networking ssh)
33773 (host-name "node1")
33774 (hosts-file (plain-file "hosts" (format #f "
33775 127.0.0.1 localhost
33778 192.168.1.200 ganeti.example.com
33779 192.168.1.201 node1.example.com node1
33780 192.168.1.202 node2.example.com node2
33783 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
33784 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
33785 (packages (append (map specification->package
33786 '("qemu" "lvm2" "drbd-utils" "ceph"
33787 ;; Add the debootstrap and guix OS providers.
33788 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
33791 (append (list (service static-networking-service-type
33792 (list (static-networking
33794 (list (network-address
33796 (value "192.168.1.201/24"))))
33798 (list (network-route
33799 (destination "default")
33800 (gateway "192.168.1.254"))))
33801 (name-servers '("192.168.1.252"
33802 "192.168.1.253")))))
33804 ;; Ganeti uses SSH to communicate between nodes.
33805 (service openssh-service-type
33806 (openssh-configuration
33807 (permit-root-login 'prohibit-password)))
33809 (service ganeti-service-type
33810 (ganeti-configuration
33811 ;; This list specifies allowed file system paths
33812 ;; for storing virtual machine images.
33813 (file-storage-paths '("/srv/ganeti/file-storage"))
33814 ;; This variable configures a single "variant" for
33815 ;; both Debootstrap and Guix that works with KVM.
33816 (os %default-ganeti-os))))
33820 Users are advised to read the
33821 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
33822 administrators guide} to learn about the various cluster options and
33823 day-to-day operations. There is also a
33824 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
33825 describing how to configure and initialize a small cluster.
33827 @defvr {Scheme Variable} ganeti-service-type
33828 This is a service type that includes all the various services that Ganeti
33831 Its value is a @code{ganeti-configuration} object that defines the package
33832 to use for CLI operations, as well as configuration for the various daemons.
33833 Allowed file storage paths and available guest operating systems are also
33834 configured through this data type.
33837 @deftp {Data Type} ganeti-configuration
33838 The @code{ganeti} service takes the following configuration options:
33841 @item @code{ganeti} (default: @code{ganeti})
33842 The @code{ganeti} package to use. It will be installed to the system profile
33843 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
33844 that the value specified here does not affect the other services as each refer
33845 to a specific @code{ganeti} package (see below).
33847 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
33848 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
33849 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
33850 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
33851 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
33852 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
33853 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
33854 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
33855 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
33856 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
33858 These options control the various daemons and cron jobs that are distributed
33859 with Ganeti. The possible values for these are described in detail below.
33860 To override a setting, you must use the configuration type for that service:
33863 (service ganeti-service-type
33864 (ganeti-configuration
33865 (rapi-configuration
33866 (ganeti-rapi-configuration
33867 (interface "eth1"))))
33868 (watcher-configuration
33869 (ganeti-watcher-configuration
33870 (rapi-ip "10.0.0.1"))))
33873 @item @code{file-storage-paths} (default: @code{'()})
33874 List of allowed directories for file storage backend.
33876 @item @code{os} (default: @code{%default-ganeti-os})
33877 List of @code{<ganeti-os>} records.
33880 In essence @code{ganeti-service-type} is shorthand for declaring each service
33884 (service ganeti-noded-service-type)
33885 (service ganeti-confd-service-type)
33886 (service ganeti-wconfd-service-type)
33887 (service ganeti-luxid-service-type)
33888 (service ganeti-kvmd-service-type)
33889 (service ganeti-mond-service-type)
33890 (service ganeti-metad-service-type)
33891 (service ganeti-watcher-service-type)
33892 (service ganeti-cleaner-service-type)
33895 Plus a service extension for @code{etc-service-type} that configures the file
33896 storage backend and OS variants.
33900 @deftp {Data Type} ganeti-os
33901 This data type is suitable for passing to the @code{os} parameter of
33902 @code{ganeti-configuration}. It takes the following parameters:
33906 The name for this OS provider. It is only used to specify where the
33907 configuration ends up. Setting it to ``debootstrap'' will create
33908 @file{/etc/ganeti/instance-debootstrap}.
33910 @item @code{extension}
33911 The file extension for variants of this OS type. For example
33912 @file{.conf} or @file{.scm}.
33914 @item @code{variants} (default: @code{'()})
33915 List of @code{ganeti-os-variant} objects for this OS.
33920 @deftp {Data Type} ganeti-os-variant
33921 This is the data type for a Ganeti OS variant. It takes the following
33926 The name of this variant.
33928 @item @code{configuration}
33929 A configuration file for this variant.
33933 @defvr {Scheme Variable} %default-debootstrap-hooks
33934 This variable contains hooks to configure networking and the GRUB bootloader.
33937 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
33938 This variable contains a list of packages suitable for a fully-virtualized guest.
33941 @deftp {Data Type} debootstrap-configuration
33943 This data type creates configuration files suitable for the debootstrap OS provider.
33946 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
33947 When not @code{#f}, this must be a G-expression that specifies a directory with
33948 scripts that will run when the OS is installed. It can also be a list of
33949 @code{(name . file-like)} pairs. For example:
33952 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
33955 That will create a directory with one executable named @code{99-hello-world}
33956 and run it every time this variant is installed. If set to @code{#f}, hooks
33957 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
33958 @item @code{proxy} (default: @code{#f})
33959 Optional HTTP proxy to use.
33960 @item @code{mirror} (default: @code{#f})
33961 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
33962 The default varies depending on the distribution.
33963 @item @code{arch} (default: @code{#f})
33964 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
33965 on an AArch64 host. Default is to use the current system architecture.
33966 @item @code{suite} (default: @code{"stable"})
33967 When set, this must be a Debian distribution ``suite'' such as @code{buster}
33968 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
33969 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
33970 List of extra packages that will get installed by dpkg in addition
33971 to the minimal system.
33972 @item @code{components} (default: @code{#f})
33973 When set, must be a list of Debian repository ``components''. For example
33974 @code{'("main" "contrib")}.
33975 @item @code{generate-cache?} (default: @code{#t})
33976 Whether to automatically cache the generated debootstrap archive.
33977 @item @code{clean-cache} (default: @code{14})
33978 Discard the cache after this amount of days. Use @code{#f} to never
33980 @item @code{partition-style} (default: @code{'msdos})
33981 The type of partition to create. When set, it must be one of
33982 @code{'msdos}, @code{'none} or a string.
33983 @item @code{partition-alignment} (default: @code{2048})
33984 Alignment of the partition in sectors.
33988 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
33989 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
33990 takes two parameters: a name and a @code{debootstrap-configuration} object.
33993 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
33994 This is a helper procedure that creates a @code{ganeti-os} record. It takes
33995 a list of variants created with @code{debootstrap-variant}.
33998 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
33999 This is a helper procedure that creates a @code{ganeti-os-variant} record for
34000 use with the Guix OS provider. It takes a name and a G-expression that returns
34001 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
34002 Guix System configuration.
34005 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
34006 This is a helper procedure that creates a @code{ganeti-os} record. It
34007 takes a list of variants produced by @code{guix-variant}.
34010 @defvr {Scheme Variable} %default-debootstrap-variants
34011 This is a convenience variable to make the debootstrap provider work
34012 ``out of the box'' without users having to declare variants manually. It
34013 contains a single debootstrap variant with the default configuration:
34016 (list (debootstrap-variant
34018 (debootstrap-configuration)))
34022 @defvr {Scheme Variable} %default-guix-variants
34023 This is a convenience variable to make the Guix OS provider work without
34024 additional configuration. It creates a virtual machine that has an SSH
34025 server, a serial console, and authorizes the Ganeti hosts SSH keys.
34028 (list (guix-variant
34030 (file-append ganeti-instance-guix
34031 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
34035 Users can implement support for OS providers unbeknownst to Guix by extending
34036 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
34042 (extension ".conf")
34044 (list (ganeti-os-variant
34046 (configuration (plain-file "bar" "this is fine"))))))
34049 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
34050 to a file in the store with contents @code{this is fine}. It also creates
34051 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
34053 Obviously this may not work for all OS providers out there. If you find the
34054 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
34056 The rest of this section documents the various services that are included by
34057 @code{ganeti-service-type}.
34059 @defvr {Scheme Variable} ganeti-noded-service-type
34060 @command{ganeti-noded} is the daemon responsible for node-specific functions
34061 within the Ganeti system. The value of this service must be a
34062 @code{ganeti-noded-configuration} object.
34065 @deftp {Data Type} ganeti-noded-configuration
34066 This is the configuration for the @code{ganeti-noded} service.
34069 @item @code{ganeti} (default: @code{ganeti})
34070 The @code{ganeti} package to use for this service.
34072 @item @code{port} (default: @code{1811})
34073 The TCP port on which the node daemon listens for network requests.
34075 @item @code{address} (default: @code{"0.0.0.0"})
34076 The network address that the daemon will bind to. The default address means
34077 bind to all available addresses.
34079 @item @code{interface} (default: @code{#f})
34080 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
34081 that the daemon will bind to.
34083 @item @code{max-clients} (default: @code{20})
34084 This sets a limit on the maximum number of simultaneous client connections
34085 that the daemon will handle. Connections above this count are accepted, but
34086 no responses will be sent until enough connections have closed.
34088 @item @code{ssl?} (default: @code{#t})
34089 Whether to use SSL/TLS to encrypt network communications. The certificate
34090 is automatically provisioned by the cluster and can be rotated with
34091 @command{gnt-cluster renew-crypto}.
34093 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
34094 This can be used to provide a specific encryption key for TLS communications.
34096 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
34097 This can be used to provide a specific certificate for TLS communications.
34099 @item @code{debug?} (default: @code{#f})
34100 When true, the daemon performs additional logging for debugging purposes.
34101 Note that this will leak encryption details to the log files, use with caution.
34106 @defvr {Scheme Variable} ganeti-confd-service-type
34107 @command{ganeti-confd} answers queries related to the configuration of a
34108 Ganeti cluster. The purpose of this daemon is to have a highly available
34109 and fast way to query cluster configuration values. It is automatically
34110 active on all @dfn{master candidates}. The value of this service must be a
34111 @code{ganeti-confd-configuration} object.
34115 @deftp {Data Type} ganeti-confd-configuration
34116 This is the configuration for the @code{ganeti-confd} service.
34119 @item @code{ganeti} (default: @code{ganeti})
34120 The @code{ganeti} package to use for this service.
34122 @item @code{port} (default: @code{1814})
34123 The UDP port on which to listen for network requests.
34125 @item @code{address} (default: @code{"0.0.0.0"})
34126 Network address that the daemon will bind to.
34128 @item @code{debug?} (default: @code{#f})
34129 When true, the daemon performs additional logging for debugging purposes.
34134 @defvr {Scheme Variable} ganeti-wconfd-service-type
34135 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
34136 about the cluster configuration and is the only entity that can accept
34137 changes to it. All jobs that need to modify the configuration will do so
34138 by sending appropriate requests to this daemon. It only runs on the
34139 @dfn{master node} and will automatically disable itself on other nodes.
34141 The value of this service must be a
34142 @code{ganeti-wconfd-configuration} object.
34145 @deftp {Data Type} ganeti-wconfd-configuration
34146 This is the configuration for the @code{ganeti-wconfd} service.
34149 @item @code{ganeti} (default: @code{ganeti})
34150 The @code{ganeti} package to use for this service.
34152 @item @code{no-voting?} (default: @code{#f})
34153 The daemon will refuse to start if the majority of cluster nodes does not
34154 agree that it is running on the master node. Set to @code{#t} to start
34155 even if a quorum can not be reached (dangerous, use with caution).
34157 @item @code{debug?} (default: @code{#f})
34158 When true, the daemon performs additional logging for debugging purposes.
34163 @defvr {Scheme Variable} ganeti-luxid-service-type
34164 @command{ganeti-luxid} is a daemon used to answer queries related to the
34165 configuration and the current live state of a Ganeti cluster. Additionally,
34166 it is the authoritative daemon for the Ganeti job queue. Jobs can be
34167 submitted via this daemon and it schedules and starts them.
34169 It takes a @code{ganeti-luxid-configuration} object.
34172 @deftp {Data Type} ganeti-luxid-configuration
34173 This is the configuration for the @code{ganeti-luxid} service.
34176 @item @code{ganeti} (default: @code{ganeti})
34177 The @code{ganeti} package to use for this service.
34179 @item @code{no-voting?} (default: @code{#f})
34180 The daemon will refuse to start if it cannot verify that the majority of
34181 cluster nodes believes that it is running on the master node. Set to
34182 @code{#t} to ignore such checks and start anyway (this can be dangerous).
34184 @item @code{debug?} (default: @code{#f})
34185 When true, the daemon performs additional logging for debugging purposes.
34190 @defvr {Scheme Variable} ganeti-rapi-service-type
34191 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
34192 the master node and can be used to perform cluster actions programmatically
34193 via a JSON-based RPC protocol.
34195 Most query operations are allowed without authentication (unless
34196 @var{require-authentication?} is set), whereas write operations require
34197 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
34198 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
34199 API documentation} for more information.
34201 The value of this service must be a @code{ganeti-rapi-configuration} object.
34204 @deftp {Data Type} ganeti-rapi-configuration
34205 This is the configuration for the @code{ganeti-rapi} service.
34208 @item @code{ganeti} (default: @code{ganeti})
34209 The @code{ganeti} package to use for this service.
34211 @item @code{require-authentication?} (default: @code{#f})
34212 Whether to require authentication even for read-only operations.
34214 @item @code{port} (default: @code{5080})
34215 The TCP port on which to listen to API requests.
34217 @item @code{address} (default: @code{"0.0.0.0"})
34218 The network address that the service will bind to. By default it listens
34219 on all configured addresses.
34221 @item @code{interface} (default: @code{#f})
34222 When set, it must specify a specific network interface such as @code{eth0}
34223 that the daemon will bind to.
34225 @item @code{max-clients} (default: @code{20})
34226 The maximum number of simultaneous client requests to handle. Further
34227 connections are allowed, but no responses are sent until enough connections
34230 @item @code{ssl?} (default: @code{#t})
34231 Whether to use SSL/TLS encryption on the RAPI port.
34233 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
34234 This can be used to provide a specific encryption key for TLS communications.
34236 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
34237 This can be used to provide a specific certificate for TLS communications.
34239 @item @code{debug?} (default: @code{#f})
34240 When true, the daemon performs additional logging for debugging purposes.
34241 Note that this will leak encryption details to the log files, use with caution.
34246 @defvr {Scheme Variable} ganeti-kvmd-service-type
34247 @command{ganeti-kvmd} is responsible for determining whether a given KVM
34248 instance was shut down by an administrator or a user. Normally Ganeti will
34249 restart an instance that was not stopped through Ganeti itself. If the
34250 cluster option @code{user_shutdown} is true, this daemon monitors the
34251 @code{QMP} socket provided by QEMU and listens for shutdown events, and
34252 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
34253 it shuts down gracefully by itself.
34255 It takes a @code{ganeti-kvmd-configuration} object.
34258 @deftp {Data Type} ganeti-kvmd-configuration
34261 @item @code{ganeti} (default: @code{ganeti})
34262 The @code{ganeti} package to use for this service.
34264 @item @code{debug?} (default: @code{#f})
34265 When true, the daemon performs additional logging for debugging purposes.
34270 @defvr {Scheme Variable} ganeti-mond-service-type
34271 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
34272 functionality. It is responsible for running data collectors and publish the
34273 collected information through a HTTP interface.
34275 It takes a @code{ganeti-mond-configuration} object.
34278 @deftp {Data Type} ganeti-mond-configuration
34281 @item @code{ganeti} (default: @code{ganeti})
34282 The @code{ganeti} package to use for this service.
34284 @item @code{port} (default: @code{1815})
34285 The port on which the daemon will listen.
34287 @item @code{address} (default: @code{"0.0.0.0"})
34288 The network address that the daemon will bind to. By default it binds to all
34289 available interfaces.
34291 @item @code{debug?} (default: @code{#f})
34292 When true, the daemon performs additional logging for debugging purposes.
34297 @defvr {Scheme Variable} ganeti-metad-service-type
34298 @command{ganeti-metad} is an optional daemon that can be used to provide
34299 information about the cluster to instances or OS install scripts.
34301 It takes a @code{ganeti-metad-configuration} object.
34304 @deftp {Data Type} ganeti-metad-configuration
34307 @item @code{ganeti} (default: @code{ganeti})
34308 The @code{ganeti} package to use for this service.
34310 @item @code{port} (default: @code{80})
34311 The port on which the daemon will listen.
34313 @item @code{address} (default: @code{#f})
34314 If set, the daemon will bind to this address only. If left unset, the behavior
34315 depends on the cluster configuration.
34317 @item @code{debug?} (default: @code{#f})
34318 When true, the daemon performs additional logging for debugging purposes.
34323 @defvr {Scheme Variable} ganeti-watcher-service-type
34324 @command{ganeti-watcher} is a script designed to run periodically and ensure
34325 the health of a cluster. It will automatically restart instances that have
34326 stopped without Ganeti's consent, and repairs DRBD links in case a node has
34327 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
34328 that are not running. If the cluster parameter @code{ensure_node_health}
34329 is set, the watcher will also shutdown instances and DRBD devices if the
34330 node it is running on is declared offline by known master candidates.
34332 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
34334 The service takes a @code{ganeti-watcher-configuration} object.
34337 @deftp {Data Type} ganeti-watcher-configuration
34340 @item @code{ganeti} (default: @code{ganeti})
34341 The @code{ganeti} package to use for this service.
34343 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
34344 How often to run the script. The default is every five minutes.
34346 @item @code{rapi-ip} (default: @code{#f})
34347 This option needs to be specified only if the RAPI daemon is configured to use
34348 a particular interface or address. By default the cluster address is used.
34350 @item @code{job-age} (default: @code{(* 6 3600)})
34351 Archive cluster jobs older than this age, specified in seconds. The default
34352 is 6 hours. This keeps @command{gnt-job list} manageable.
34354 @item @code{verify-disks?} (default: @code{#t})
34355 If this is @code{#f}, the watcher will not try to repair broken DRBD links
34356 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
34359 @item @code{debug?} (default: @code{#f})
34360 When @code{#t}, the script performs additional logging for debugging purposes.
34365 @defvr {Scheme Variable} ganeti-cleaner-service-type
34366 @command{ganeti-cleaner} is a script designed to run periodically and remove
34367 old files from the cluster. This service type controls two @dfn{cron jobs}:
34368 one intended for the master node that permanently purges old cluster jobs,
34369 and one intended for every node that removes expired X509 certificates, keys,
34370 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
34371 it is safe to include even on non-master nodes as it will disable itself as
34374 It takes a @code{ganeti-cleaner-configuration} object.
34377 @deftp {Data Type} ganeti-cleaner-configuration
34380 @item @code{ganeti} (default: @code{ganeti})
34381 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
34383 @item @code{master-schedule} (default: @code{"45 1 * * *"})
34384 How often to run the master cleaning job. The default is once per day, at
34387 @item @code{node-schedule} (default: @code{"45 2 * * *"})
34388 How often to run the node cleaning job. The default is once per day, at
34394 @node Version Control Services
34395 @subsection Version Control Services
34397 The @code{(gnu services version-control)} module provides a service to
34398 allow remote access to local Git repositories. There are three options:
34399 the @code{git-daemon-service}, which provides access to repositories via
34400 the @code{git://} unsecured TCP-based protocol, extending the
34401 @code{nginx} web server to proxy some requests to
34402 @code{git-http-backend}, or providing a web interface with
34403 @code{cgit-service-type}.
34405 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
34407 Return a service that runs @command{git daemon}, a simple TCP server to
34408 expose repositories over the Git protocol for anonymous access.
34410 The optional @var{config} argument should be a
34411 @code{<git-daemon-configuration>} object, by default it allows read-only
34412 access to exported@footnote{By creating the magic file
34413 @file{git-daemon-export-ok} in the repository directory.} repositories under
34418 @deftp {Data Type} git-daemon-configuration
34419 Data type representing the configuration for @code{git-daemon-service}.
34422 @item @code{package} (default: @code{git})
34423 Package object of the Git distributed version control system.
34425 @item @code{export-all?} (default: @code{#f})
34426 Whether to allow access for all Git repositories, even if they do not
34427 have the @file{git-daemon-export-ok} file.
34429 @item @code{base-path} (default: @file{/srv/git})
34430 Whether to remap all the path requests as relative to the given path.
34431 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
34432 @samp{example.com}, then if you later try to pull
34433 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
34434 path as @file{/srv/git/hello.git}.
34436 @item @code{user-path} (default: @code{#f})
34437 Whether to allow @code{~user} notation to be used in requests. When
34438 specified with empty string, requests to
34439 @indicateurl{git://host/~alice/foo} is taken as a request to access
34440 @code{foo} repository in the home directory of user @code{alice}. If
34441 @code{(user-path "@var{path}")} is specified, the same request is taken
34442 as a request to access @file{@var{path}/foo} repository in the home
34443 directory of user @code{alice}.
34445 @item @code{listen} (default: @code{'()})
34446 Whether to listen on specific IP addresses or hostnames, defaults to
34449 @item @code{port} (default: @code{#f})
34450 Whether to listen on an alternative port, which defaults to 9418.
34452 @item @code{whitelist} (default: @code{'()})
34453 If not empty, only allow access to this list of directories.
34455 @item @code{extra-options} (default: @code{'()})
34456 Extra options will be passed to @command{git daemon}, please run
34457 @command{man git-daemon} for more information.
34462 The @code{git://} protocol lacks authentication. When you pull from a
34463 repository fetched via @code{git://}, you don't know whether the data you
34464 receive was modified or is even coming from the specified host, and your
34465 connection is subject to eavesdropping. It's better to use an authenticated
34466 and encrypted transport, such as @code{https}. Although Git allows you
34467 to serve repositories using unsophisticated file-based web servers,
34468 there is a faster protocol implemented by the @code{git-http-backend}
34469 program. This program is the back-end of a proper Git web service. It
34470 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
34471 on running the necessary @code{fcgiwrap} daemon.
34473 Guix has a separate configuration data type for serving Git repositories
34476 @deftp {Data Type} git-http-configuration
34477 Data type representing the configuration for a future
34478 @code{git-http-service-type}; can currently be used to configure Nginx
34479 through @code{git-http-nginx-location-configuration}.
34482 @item @code{package} (default: @var{git})
34483 Package object of the Git distributed version control system.
34485 @item @code{git-root} (default: @file{/srv/git})
34486 Directory containing the Git repositories to expose to the world.
34488 @item @code{export-all?} (default: @code{#f})
34489 Whether to expose access for all Git repositories in @var{git-root},
34490 even if they do not have the @file{git-daemon-export-ok} file.
34492 @item @code{uri-path} (default: @samp{/git/})
34493 Path prefix for Git access. With the default @samp{/git/} prefix, this
34494 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
34495 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
34496 with this prefix are not passed on to this Git instance.
34498 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
34499 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
34504 There is no @code{git-http-service-type}, currently; instead you can
34505 create an @code{nginx-location-configuration} from a
34506 @code{git-http-configuration} and then add that location to a web
34509 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
34510 [config=(git-http-configuration)]
34511 Compute an @code{nginx-location-configuration} that corresponds to the
34512 given Git http configuration. An example nginx service definition to
34513 serve the default @file{/srv/git} over HTTPS might be:
34516 (service nginx-service-type
34517 (nginx-configuration
34520 (nginx-server-configuration
34521 (listen '("443 ssl"))
34522 (server-name "git.my-host.org")
34524 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
34525 (ssl-certificate-key
34526 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
34529 (git-http-nginx-location-configuration
34530 (git-http-configuration (uri-path "/"))))))))))
34533 This example assumes that you are using Let's Encrypt to get your TLS
34534 certificate. @xref{Certificate Services}. The default @code{certbot}
34535 service will redirect all HTTP traffic on @code{git.my-host.org} to
34536 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
34537 system services. @xref{Web Services}.
34540 @subsubheading Cgit Service
34542 @cindex Cgit service
34543 @cindex Git, web interface
34544 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
34545 repositories written in C.
34547 The following example will configure the service with default values.
34548 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
34551 (service cgit-service-type)
34554 The @code{file-object} type designates either a file-like object
34555 (@pxref{G-Expressions, file-like objects}) or a string.
34557 @c %start of fragment
34559 Available @code{cgit-configuration} fields are:
34561 @deftypevr {@code{cgit-configuration} parameter} package package
34566 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
34567 NGINX configuration.
34571 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
34572 Specifies a command which will be invoked to format the content of about
34573 pages (both top-level and for each repository).
34575 Defaults to @samp{""}.
34579 @deftypevr {@code{cgit-configuration} parameter} string agefile
34580 Specifies a path, relative to each repository path, which can be used to
34581 specify the date and time of the youngest commit in the repository.
34583 Defaults to @samp{""}.
34587 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
34588 Specifies a command that will be invoked for authenticating repository
34591 Defaults to @samp{""}.
34595 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
34596 Flag which, when set to @samp{age}, enables date ordering in the branch
34597 ref list, and when set @samp{name} enables ordering by branch name.
34599 Defaults to @samp{"name"}.
34603 @deftypevr {@code{cgit-configuration} parameter} string cache-root
34604 Path used to store the cgit cache entries.
34606 Defaults to @samp{"/var/cache/cgit"}.
34610 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
34611 Number which specifies the time-to-live, in minutes, for the cached
34612 version of repository pages accessed with a fixed SHA1.
34614 Defaults to @samp{-1}.
34618 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
34619 Number which specifies the time-to-live, in minutes, for the cached
34620 version of repository pages accessed without a fixed SHA1.
34622 Defaults to @samp{5}.
34626 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
34627 Number which specifies the time-to-live, in minutes, for the cached
34628 version of the repository summary page.
34630 Defaults to @samp{5}.
34634 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
34635 Number which specifies the time-to-live, in minutes, for the cached
34636 version of the repository index page.
34638 Defaults to @samp{5}.
34642 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
34643 Number which specifies the time-to-live, in minutes, for the result of
34644 scanning a path for Git repositories.
34646 Defaults to @samp{15}.
34650 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
34651 Number which specifies the time-to-live, in minutes, for the cached
34652 version of the repository about page.
34654 Defaults to @samp{15}.
34658 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
34659 Number which specifies the time-to-live, in minutes, for the cached
34660 version of snapshots.
34662 Defaults to @samp{5}.
34666 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
34667 The maximum number of entries in the cgit cache. When set to @samp{0},
34668 caching is disabled.
34670 Defaults to @samp{0}.
34674 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
34675 Sort items in the repo list case sensitively.
34677 Defaults to @samp{#t}.
34681 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
34682 List of common prefixes which, when combined with a repository URL,
34683 generates valid clone URLs for the repository.
34685 Defaults to @samp{()}.
34689 @deftypevr {@code{cgit-configuration} parameter} list clone-url
34690 List of @code{clone-url} templates.
34692 Defaults to @samp{()}.
34696 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
34697 Command which will be invoked to format commit messages.
34699 Defaults to @samp{""}.
34703 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
34704 Flag which, when set to @samp{date}, enables strict date ordering in the
34705 commit log, and when set to @samp{topo} enables strict topological
34708 Defaults to @samp{"git log"}.
34712 @deftypevr {@code{cgit-configuration} parameter} file-object css
34713 URL which specifies the css document to include in all cgit pages.
34715 Defaults to @samp{"/share/cgit/cgit.css"}.
34719 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
34720 Specifies a command which will be invoked to format names and email
34721 address of committers, authors, and taggers, as represented in various
34722 places throughout the cgit interface.
34724 Defaults to @samp{""}.
34728 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
34729 Flag which, when set to @samp{#t}, will make cgit generate a HTML
34730 fragment suitable for embedding in other HTML pages.
34732 Defaults to @samp{#f}.
34736 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
34737 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
34738 commit history graph to the left of the commit messages in the
34739 repository log page.
34741 Defaults to @samp{#f}.
34745 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
34746 Flag which, when set to @samp{#t}, allows all filter settings to be
34747 overridden in repository-specific cgitrc files.
34749 Defaults to @samp{#f}.
34753 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
34754 Flag which, when set to @samp{#t}, allows users to follow a file in the
34757 Defaults to @samp{#f}.
34761 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
34762 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
34765 Defaults to @samp{#t}.
34769 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
34770 Flag which, when set to @samp{#t}, will make cgit generate extra links
34771 "summary", "commit", "tree" for each repo in the repository index.
34773 Defaults to @samp{#f}.
34777 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
34778 Flag which, when set to @samp{#t}, will make cgit display the owner of
34779 each repo in the repository index.
34781 Defaults to @samp{#t}.
34785 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
34786 Flag which, when set to @samp{#t}, will make cgit print the number of
34787 modified files for each commit on the repository log page.
34789 Defaults to @samp{#f}.
34793 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
34794 Flag which, when set to @samp{#t}, will make cgit print the number of
34795 added and removed lines for each commit on the repository log page.
34797 Defaults to @samp{#f}.
34801 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
34802 Flag which, when set to @code{#t}, will make cgit display remote
34803 branches in the summary and refs views.
34805 Defaults to @samp{#f}.
34809 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
34810 Flag which, when set to @code{1}, will make cgit use the subject of the
34811 parent commit as link text when generating links to parent commits in
34814 Defaults to @samp{#f}.
34818 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
34819 Flag which, when set to @samp{#t}, will make cgit use the subject of the
34820 parent commit as link text when generating links to parent commits in
34823 Defaults to @samp{#f}.
34827 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
34828 Flag which, when set to @samp{#t}, will make cgit generate linenumber
34829 links for plaintext blobs printed in the tree view.
34831 Defaults to @samp{#t}.
34835 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
34836 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
34837 set any repo specific settings.
34839 Defaults to @samp{#f}.
34843 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
34844 URL used as link to a shortcut icon for cgit.
34846 Defaults to @samp{"/favicon.ico"}.
34850 @deftypevr {@code{cgit-configuration} parameter} string footer
34851 The content of the file specified with this option will be included
34852 verbatim at the bottom of all pages (i.e.@: it replaces the standard
34853 "generated by..."@: message).
34855 Defaults to @samp{""}.
34859 @deftypevr {@code{cgit-configuration} parameter} string head-include
34860 The content of the file specified with this option will be included
34861 verbatim in the HTML HEAD section on all pages.
34863 Defaults to @samp{""}.
34867 @deftypevr {@code{cgit-configuration} parameter} string header
34868 The content of the file specified with this option will be included
34869 verbatim at the top of all pages.
34871 Defaults to @samp{""}.
34875 @deftypevr {@code{cgit-configuration} parameter} file-object include
34876 Name of a configfile to include before the rest of the current config-
34879 Defaults to @samp{""}.
34883 @deftypevr {@code{cgit-configuration} parameter} string index-header
34884 The content of the file specified with this option will be included
34885 verbatim above the repository index.
34887 Defaults to @samp{""}.
34891 @deftypevr {@code{cgit-configuration} parameter} string index-info
34892 The content of the file specified with this option will be included
34893 verbatim below the heading on the repository index page.
34895 Defaults to @samp{""}.
34899 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
34900 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
34901 in the servers timezone.
34903 Defaults to @samp{#f}.
34907 @deftypevr {@code{cgit-configuration} parameter} file-object logo
34908 URL which specifies the source of an image which will be used as a logo
34911 Defaults to @samp{"/share/cgit/cgit.png"}.
34915 @deftypevr {@code{cgit-configuration} parameter} string logo-link
34916 URL loaded when clicking on the cgit logo image.
34918 Defaults to @samp{""}.
34922 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
34923 Command which will be invoked to format the Owner column of the main
34926 Defaults to @samp{""}.
34930 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
34931 Number of items to display in atom feeds view.
34933 Defaults to @samp{10}.
34937 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
34938 Number of entries to list per page in "log" view.
34940 Defaults to @samp{50}.
34944 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
34945 Number of commit message characters to display in "log" view.
34947 Defaults to @samp{80}.
34951 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
34952 Specifies the number of entries to list per page on the repository index
34955 Defaults to @samp{50}.
34959 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
34960 Specifies the maximum number of repo description characters to display
34961 on the repository index page.
34963 Defaults to @samp{80}.
34967 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
34968 Specifies the maximum size of a blob to display HTML for in KBytes.
34970 Defaults to @samp{0}.
34974 @deftypevr {@code{cgit-configuration} parameter} string max-stats
34975 Maximum statistics period. Valid values are @samp{week},@samp{month},
34976 @samp{quarter} and @samp{year}.
34978 Defaults to @samp{""}.
34982 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
34983 Mimetype for the specified filename extension.
34985 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
34986 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
34987 "image/png") (svg "image/svg+xml"))}.
34991 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
34992 Specifies the file to use for automatic mimetype lookup.
34994 Defaults to @samp{""}.
34998 @deftypevr {@code{cgit-configuration} parameter} string module-link
34999 Text which will be used as the formatstring for a hyperlink when a
35000 submodule is printed in a directory listing.
35002 Defaults to @samp{""}.
35006 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
35007 If set to the value @samp{#t} caching will be disabled.
35009 Defaults to @samp{#f}.
35013 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
35014 If set to @samp{#t} showing full author email addresses will be
35017 Defaults to @samp{#f}.
35021 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
35022 Flag which, when set to @samp{#t}, will make cgit omit the standard
35023 header on all pages.
35025 Defaults to @samp{#f}.
35029 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
35030 A list of subdirectories inside of @code{repository-directory}, relative
35031 to it, that should loaded as Git repositories. An empty list means that
35032 all subdirectories will be loaded.
35034 Defaults to @samp{()}.
35038 @deftypevr {@code{cgit-configuration} parameter} file-object readme
35039 Text which will be used as default value for @code{cgit-repo-readme}.
35041 Defaults to @samp{""}.
35045 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
35046 If set to @code{#t} and @code{repository-directory} is enabled, if any
35047 repositories are found with a suffix of @code{.git}, this suffix will be
35048 removed for the URL and name.
35050 Defaults to @samp{#f}.
35054 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
35055 Maximum number of files to consider when detecting renames.
35057 Defaults to @samp{-1}.
35061 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
35062 The way in which repositories in each section are sorted.
35064 Defaults to @samp{""}.
35068 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
35069 Text used as content for the @code{robots} meta-tag.
35071 Defaults to @samp{("noindex" "nofollow")}.
35075 @deftypevr {@code{cgit-configuration} parameter} string root-desc
35076 Text printed below the heading on the repository index page.
35078 Defaults to @samp{"a fast webinterface for the git dscm"}.
35082 @deftypevr {@code{cgit-configuration} parameter} string root-readme
35083 The content of the file specified with this option will be included
35084 verbatim below the ``about'' link on the repository index page.
35086 Defaults to @samp{""}.
35090 @deftypevr {@code{cgit-configuration} parameter} string root-title
35091 Text printed as heading on the repository index page.
35093 Defaults to @samp{""}.
35097 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
35098 If set to @samp{#t} and repository-directory is enabled,
35099 repository-directory will recurse into directories whose name starts
35100 with a period. Otherwise, repository-directory will stay away from such
35101 directories, considered as ``hidden''. Note that this does not apply to
35102 the @file{.git} directory in non-bare repos.
35104 Defaults to @samp{#f}.
35108 @deftypevr {@code{cgit-configuration} parameter} list snapshots
35109 Text which specifies the default set of snapshot formats that cgit
35110 generates links for.
35112 Defaults to @samp{()}.
35116 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
35117 Name of the directory to scan for repositories (represents
35120 Defaults to @samp{"/srv/git"}.
35124 @deftypevr {@code{cgit-configuration} parameter} string section
35125 The name of the current repository section - all repositories defined
35126 after this option will inherit the current section name.
35128 Defaults to @samp{""}.
35132 @deftypevr {@code{cgit-configuration} parameter} string section-sort
35133 Flag which, when set to @samp{1}, will sort the sections on the
35134 repository listing by name.
35136 Defaults to @samp{""}.
35140 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
35141 A number which, if defined prior to repository-directory, specifies how
35142 many path elements from each repo path to use as a default section name.
35144 Defaults to @samp{0}.
35148 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
35149 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
35152 Defaults to @samp{#f}.
35156 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
35157 Specifies a command which will be invoked to format plaintext blobs in
35160 Defaults to @samp{""}.
35164 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
35165 Specifies the number of branches to display in the repository ``summary''
35168 Defaults to @samp{10}.
35172 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
35173 Specifies the number of log entries to display in the repository
35176 Defaults to @samp{10}.
35180 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
35181 Specifies the number of tags to display in the repository ``summary''
35184 Defaults to @samp{10}.
35188 @deftypevr {@code{cgit-configuration} parameter} string strict-export
35189 Filename which, if specified, needs to be present within the repository
35190 for cgit to allow access to that repository.
35192 Defaults to @samp{""}.
35196 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
35197 URL which, if specified, will be used as root for all cgit links.
35199 Defaults to @samp{"/"}.
35203 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
35204 A list of @dfn{cgit-repo} records to use with config.
35206 Defaults to @samp{()}.
35208 Available @code{repository-cgit-configuration} fields are:
35210 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
35211 A mask of snapshot formats for this repo that cgit generates links for,
35212 restricted by the global @code{snapshots} setting.
35214 Defaults to @samp{()}.
35218 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
35219 Override the default @code{source-filter}.
35221 Defaults to @samp{""}.
35225 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
35226 The relative URL used to access the repository.
35228 Defaults to @samp{""}.
35232 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
35233 Override the default @code{about-filter}.
35235 Defaults to @samp{""}.
35239 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
35240 Flag which, when set to @samp{age}, enables date ordering in the branch
35241 ref list, and when set to @samp{name} enables ordering by branch name.
35243 Defaults to @samp{""}.
35247 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
35248 A list of URLs which can be used to clone repo.
35250 Defaults to @samp{()}.
35254 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
35255 Override the default @code{commit-filter}.
35257 Defaults to @samp{""}.
35261 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
35262 Flag which, when set to @samp{date}, enables strict date ordering in the
35263 commit log, and when set to @samp{topo} enables strict topological
35266 Defaults to @samp{""}.
35270 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
35271 The name of the default branch for this repository. If no such branch
35272 exists in the repository, the first branch name (when sorted) is used as
35273 default instead. By default branch pointed to by HEAD, or ``master'' if
35274 there is no suitable HEAD.
35276 Defaults to @samp{""}.
35280 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
35281 The value to show as repository description.
35283 Defaults to @samp{""}.
35287 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
35288 The value to show as repository homepage.
35290 Defaults to @samp{""}.
35294 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
35295 Override the default @code{email-filter}.
35297 Defaults to @samp{""}.
35301 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
35302 A flag which can be used to disable the global setting
35303 @code{enable-commit-graph?}.
35305 Defaults to @samp{disabled}.
35309 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
35310 A flag which can be used to disable the global setting
35311 @code{enable-log-filecount?}.
35313 Defaults to @samp{disabled}.
35317 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
35318 A flag which can be used to disable the global setting
35319 @code{enable-log-linecount?}.
35321 Defaults to @samp{disabled}.
35325 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
35326 Flag which, when set to @code{#t}, will make cgit display remote
35327 branches in the summary and refs views.
35329 Defaults to @samp{disabled}.
35333 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
35334 A flag which can be used to override the global setting
35335 @code{enable-subject-links?}.
35337 Defaults to @samp{disabled}.
35341 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
35342 A flag which can be used to override the global setting
35343 @code{enable-html-serving?}.
35345 Defaults to @samp{disabled}.
35349 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
35350 Flag which, when set to @code{#t}, hides the repository from the
35353 Defaults to @samp{#f}.
35357 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
35358 Flag which, when set to @samp{#t}, ignores the repository.
35360 Defaults to @samp{#f}.
35364 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
35365 URL which specifies the source of an image which will be used as a logo
35366 on this repo’s pages.
35368 Defaults to @samp{""}.
35372 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
35373 URL loaded when clicking on the cgit logo image.
35375 Defaults to @samp{""}.
35379 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
35380 Override the default @code{owner-filter}.
35382 Defaults to @samp{""}.
35386 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
35387 Text which will be used as the formatstring for a hyperlink when a
35388 submodule is printed in a directory listing. The arguments for the
35389 formatstring are the path and SHA1 of the submodule commit.
35391 Defaults to @samp{""}.
35395 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
35396 Text which will be used as the formatstring for a hyperlink when a
35397 submodule with the specified subdirectory path is printed in a directory
35400 Defaults to @samp{()}.
35404 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
35405 Override the default maximum statistics period.
35407 Defaults to @samp{""}.
35411 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
35412 The value to show as repository name.
35414 Defaults to @samp{""}.
35418 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
35419 A value used to identify the owner of the repository.
35421 Defaults to @samp{""}.
35425 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
35426 An absolute path to the repository directory.
35428 Defaults to @samp{""}.
35432 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
35433 A path (relative to repo) which specifies a file to include verbatim as
35434 the ``About'' page for this repo.
35436 Defaults to @samp{""}.
35440 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
35441 The name of the current repository section - all repositories defined
35442 after this option will inherit the current section name.
35444 Defaults to @samp{""}.
35448 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
35449 Extra options will be appended to cgitrc file.
35451 Defaults to @samp{()}.
35457 @deftypevr {@code{cgit-configuration} parameter} list extra-options
35458 Extra options will be appended to cgitrc file.
35460 Defaults to @samp{()}.
35465 @c %end of fragment
35467 However, it could be that you just want to get a @code{cgitrc} up and
35468 running. In that case, you can pass an @code{opaque-cgit-configuration}
35469 as a record to @code{cgit-service-type}. As its name indicates, an
35470 opaque configuration does not have easy reflective capabilities.
35472 Available @code{opaque-cgit-configuration} fields are:
35474 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
35478 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
35479 The contents of the @code{cgitrc}, as a string.
35482 For example, if your @code{cgitrc} is just the empty string, you
35483 could instantiate a cgit service like this:
35486 (service cgit-service-type
35487 (opaque-cgit-configuration
35491 @subsubheading Gitolite Service
35493 @cindex Gitolite service
35494 @cindex Git, hosting
35495 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
35496 repositories on a central server.
35498 Gitolite can handle multiple repositories and users, and supports flexible
35499 configuration of the permissions for the users on the repositories.
35501 The following example will configure Gitolite using the default @code{git}
35502 user, and the provided SSH public key.
35505 (service gitolite-service-type
35506 (gitolite-configuration
35507 (admin-pubkey (plain-file
35509 "ssh-rsa AAAA... guix@@example.com"))))
35512 Gitolite is configured through a special admin repository which you can clone,
35513 for example, if you setup Gitolite on @code{example.com}, you would run the
35514 following command to clone the admin repository.
35517 git clone git@@example.com:gitolite-admin
35520 When the Gitolite service is activated, the provided @code{admin-pubkey} will
35521 be inserted in to the @file{keydir} directory in the gitolite-admin
35522 repository. If this results in a change in the repository, it will be
35523 committed using the message ``gitolite setup by GNU Guix''.
35525 @deftp {Data Type} gitolite-configuration
35526 Data type representing the configuration for @code{gitolite-service-type}.
35529 @item @code{package} (default: @var{gitolite})
35530 Gitolite package to use.
35532 @item @code{user} (default: @var{git})
35533 User to use for Gitolite. This will be user that you use when accessing
35536 @item @code{group} (default: @var{git})
35537 Group to use for Gitolite.
35539 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
35540 Directory in which to store the Gitolite configuration and repositories.
35542 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
35543 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
35544 representing the configuration for Gitolite.
35546 @item @code{admin-pubkey} (default: @var{#f})
35547 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
35548 setup Gitolite. This will be inserted in to the @file{keydir} directory
35549 within the gitolite-admin repository.
35551 To specify the SSH key as a string, use the @code{plain-file} function.
35554 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
35560 @deftp {Data Type} gitolite-rc-file
35561 Data type representing the Gitolite RC file.
35564 @item @code{umask} (default: @code{#o0077})
35565 This controls the permissions Gitolite sets on the repositories and their
35568 A value like @code{#o0027} will give read access to the group used by Gitolite
35569 (by default: @code{git}). This is necessary when using Gitolite with software
35570 like cgit or gitweb.
35572 @item @code{unsafe-pattern} (default: @code{#f})
35573 An optional Perl regular expression for catching unsafe configurations in
35574 the configuration file. See
35575 @uref{https://gitolite.com/gitolite/git-config.html#compensating-for-unsafe_patt,
35576 Gitolite's documentation} for more information.
35578 When the value is not @code{#f}, it should be a string containing a Perl
35579 regular expression, such as @samp{"[`~#\$\&()|;<>]"}, which is the default
35580 value used by gitolite. It rejects any special character in configuration
35581 that might be interpreted by a shell, which is useful when sharing the
35582 administration burden with other people that do not otherwise have shell
35583 access on the server.
35585 @item @code{git-config-keys} (default: @code{""})
35586 Gitolite allows you to set git config values using the @samp{config}
35587 keyword. This setting allows control over the config keys to accept.
35589 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
35590 Set the role names allowed to be used by users running the perms command.
35592 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
35593 This setting controls the commands and features to enable within Gitolite.
35599 @subsubheading Gitile Service
35601 @cindex Gitile service
35603 @uref{https://git.lepiller.eu/gitile, Gitile} is a Git forge for viewing
35604 public git repository contents from a web browser.
35606 Gitile works best in collaboration with Gitolite, and will serve the public
35607 repositories from Gitolite by default. The service should listen only on
35608 a local port, and a webserver should be configured to serve static resources.
35609 The gitile service provides an easy way to extend the Nginx service for
35610 that purpose (@pxref{NGINX}).
35612 The following example will configure Gitile to serve repositories from a
35613 custom location, with some default messages for the home page and the
35617 (service gitile-service-type
35618 (gitile-configuration
35619 (repositories "/srv/git")
35620 (base-git-url "https://myweb.site/git")
35621 (index-title "My git repositories")
35622 (intro '((p "This is all my public work!")))
35623 (footer '((p "This is the end")))
35624 (nginx-server-block
35625 (nginx-server-configuration
35627 "/etc/letsencrypt/live/myweb.site/fullchain.pem")
35628 (ssl-certificate-key
35629 "/etc/letsencrypt/live/myweb.site/privkey.pem")
35630 (listen '("443 ssl http2" "[::]:443 ssl http2"))
35633 ;; Allow for https anonymous fetch on /git/ urls.
35634 (git-http-nginx-location-configuration
35635 (git-http-configuration
35637 (git-root "/var/lib/gitolite/repositories")))))))))
35640 In addition to the configuration record, you should configure your git
35641 repositories to contain some optional information. First, your public
35642 repositories need to contain the @file{git-daemon-export-ok} magic file
35643 that allows Git to export the repository. Gitile uses the presence of this
35644 file to detect public repositories it should make accessible. To do so with
35645 Gitolite for instance, modify your @file{conf/gitolite.conf} to include
35646 this in the repositories you want to make public:
35653 In addition, Gitile can read the repository configuration to display more
35654 information on the repository. Gitile uses the gitweb namespace for its
35655 configuration. As an example, you can use the following in your
35656 @file{conf/gitolite.conf}:
35661 desc = A long description, optionally with <i>HTML</i>, shown on the index page
35662 config gitweb.name = The Foo Project
35663 config gitweb.synopsis = A short description, shown on the main page of the project
35666 Do not forget to commit and push these changes once you are satisfied. You
35667 may need to change your gitolite configuration to allow the previous
35668 configuration options to be set. One way to do that is to add the
35669 following service definition:
35672 (service gitolite-service-type
35673 (gitolite-configuration
35674 (admin-pubkey (local-file "key.pub"))
35678 ;; Allow to set any configuration key
35679 (git-config-keys ".*")
35680 ;; Allow any text as a valid configuration value
35681 (unsafe-patt "^$")))))
35684 @deftp {Data Type} gitile-configuration
35685 Data type representing the configuration for @code{gitile-service-type}.
35688 @item @code{package} (default: @var{gitile})
35689 Gitile package to use.
35691 @item @code{host} (default: @code{"localhost"})
35692 The host on which gitile is listening.
35694 @item @code{port} (default: @code{8080})
35695 The port on which gitile is listening.
35697 @item @code{database} (default: @code{"/var/lib/gitile/gitile-db.sql"})
35698 The location of the database.
35700 @item @code{repositories} (default: @code{"/var/lib/gitolite/repositories"})
35701 The location of the repositories. Note that only public repositories will
35702 be shown by Gitile. To make a repository public, add an empty
35703 @file{git-daemon-export-ok} file at the root of that repository.
35705 @item @code{base-git-url}
35706 The base git url that will be used to show clone commands.
35708 @item @code{index-title} (default: @code{"Index"})
35709 The page title for the index page that lists all the available repositories.
35711 @item @code{intro} (default: @code{'()})
35712 The intro content, as a list of sxml expressions. This is shown above the list
35713 of repositories, on the index page.
35715 @item @code{footer} (default: @code{'()})
35716 The footer content, as a list of sxml expressions. This is shown on every
35717 page served by Gitile.
35719 @item @code{nginx-server-block}
35720 An nginx server block that will be extended and used as a reverse proxy by
35721 Gitile to serve its pages, and as a normal web server to serve its assets.
35723 You can use this block to add more custom URLs to your domain, such as a
35724 @code{/git/} URL for anonymous clones, or serving any other files you would
35730 @node Game Services
35731 @subsection Game Services
35733 @subsubheading The Battle for Wesnoth Service
35735 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
35736 based tactical strategy game, with several single player campaigns, and
35737 multiplayer games (both networked and local).
35739 @defvar {Scheme Variable} wesnothd-service-type
35740 Service type for the wesnothd service. Its value must be a
35741 @code{wesnothd-configuration} object. To run wesnothd in the default
35742 configuration, instantiate it as:
35745 (service wesnothd-service-type)
35749 @deftp {Data Type} wesnothd-configuration
35750 Data type representing the configuration of @command{wesnothd}.
35753 @item @code{package} (default: @code{wesnoth-server})
35754 The wesnoth server package to use.
35756 @item @code{port} (default: @code{15000})
35757 The port to bind the server to.
35762 @node PAM Mount Service
35763 @subsection PAM Mount Service
35766 The @code{(gnu services pam-mount)} module provides a service allowing
35767 users to mount volumes when they log in. It should be able to mount any
35768 volume format supported by the system.
35770 @defvar {Scheme Variable} pam-mount-service-type
35771 Service type for PAM Mount support.
35774 @deftp {Data Type} pam-mount-configuration
35775 Data type representing the configuration of PAM Mount.
35777 It takes the following parameters:
35781 The configuration rules that will be used to generate
35782 @file{/etc/security/pam_mount.conf.xml}.
35784 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
35785 Guile Reference Manual}), and the default ones don't mount anything for
35789 `((debug (@@ (enable "0")))
35790 (mntoptions (@@ (allow ,(string-join
35791 '("nosuid" "nodev" "loop"
35792 "encryption" "fsck" "nonempty"
35793 "allow_root" "allow_other")
35795 (mntoptions (@@ (require "nosuid,nodev")))
35796 (logout (@@ (wait "0")
35800 (mkmountpoint (@@ (enable "1")
35804 Some @code{volume} elements must be added to automatically mount volumes
35805 at login. Here's an example allowing the user @code{alice} to mount her
35806 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
35807 the partition where he stores his data:
35810 (define pam-mount-rules
35811 `((debug (@@ (enable "0")))
35812 (volume (@@ (user "alice")
35815 (mountpoint "/home/alice")))
35816 (volume (@@ (user "bob")
35819 (mountpoint "/home/bob/data")
35820 (options "defaults,autodefrag,compress")))
35821 (mntoptions (@@ (allow ,(string-join
35822 '("nosuid" "nodev" "loop"
35823 "encryption" "fsck" "nonempty"
35824 "allow_root" "allow_other")
35826 (mntoptions (@@ (require "nosuid,nodev")))
35827 (logout (@@ (wait "0")
35831 (mkmountpoint (@@ (enable "1")
35832 (remove "true")))))
35834 (service pam-mount-service-type
35835 (pam-mount-configuration
35836 (rules pam-mount-rules)))
35839 The complete list of possible options can be found in the man page for
35840 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
35845 @node Guix Services
35846 @subsection Guix Services
35848 @subsubheading Guix Build Coordinator
35849 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
35850 Coordinator} aids in distributing derivation builds among machines
35851 running an @dfn{agent}. The build daemon is still used to build the
35852 derivations, but the Guix Build Coordinator manages allocating builds
35853 and working with the results.
35855 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
35856 more connected @dfn{agent} processes. The coordinator process handles
35857 clients submitting builds, and allocating builds to agents. The agent
35858 processes talk to a build daemon to actually perform the builds, then
35859 send the results back to the coordinator.
35861 There is a script to run the coordinator component of the Guix Build
35862 Coordinator, but the Guix service uses a custom Guile script instead, to
35863 provide better integration with G-expressions used in the configuration.
35865 @defvar {Scheme Variable} guix-build-coordinator-service-type
35866 Service type for the Guix Build Coordinator. Its value must be a
35867 @code{guix-build-coordinator-configuration} object.
35870 @deftp {Data Type} guix-build-coordinator-configuration
35871 Data type representing the configuration of the Guix Build Coordinator.
35874 @item @code{package} (default: @code{guix-build-coordinator})
35875 The Guix Build Coordinator package to use.
35877 @item @code{user} (default: @code{"guix-build-coordinator"})
35878 The system user to run the service as.
35880 @item @code{group} (default: @code{"guix-build-coordinator"})
35881 The system group to run the service as.
35883 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
35884 The URI to use for the database.
35886 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
35887 The URI describing how to listen to requests from agent processes.
35889 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
35890 The URI describing how to listen to requests from clients. The client
35891 API allows submitting builds and currently isn't authenticated, so take
35892 care when configuring this value.
35894 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
35895 A G-expression for the allocation strategy to be used. This is a
35896 procedure that takes the datastore as an argument and populates the
35897 allocation plan in the database.
35899 @item @code{hooks} (default: @var{'()})
35900 An association list of hooks. These provide a way to execute arbitrary
35901 code upon certain events, like a build result being processed.
35903 @item @code{parallel-hooks} (default: @var{'()})
35904 Hooks can be configured to run in parallel. This parameter is an
35905 association list of hooks to do in parallel, where the key is the symbol
35906 for the hook and the value is the number of threads to run.
35908 @item @code{guile} (default: @code{guile-3.0-latest})
35909 The Guile package with which to run the Guix Build Coordinator.
35914 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
35915 Service type for a Guix Build Coordinator agent. Its value must be a
35916 @code{guix-build-coordinator-agent-configuration} object.
35919 @deftp {Data Type} guix-build-coordinator-agent-configuration
35920 Data type representing the configuration a Guix Build Coordinator agent.
35923 @item @code{package} (default: @code{guix-build-coordinator/agent-only})
35924 The Guix Build Coordinator package to use.
35926 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
35927 The system user to run the service as.
35929 @item @code{coordinator} (default: @code{"http://localhost:8745"})
35930 The URI to use when connecting to the coordinator.
35932 @item @code{authentication}
35933 Record describing how this agent should authenticate with the
35934 coordinator. Possible record types are described below.
35936 @item @code{systems} (default: @code{#f})
35937 The systems for which this agent should fetch builds. The agent process
35938 will use the current system it's running on as the default.
35940 @item @code{max-parallel-builds} (default: @code{1})
35941 The number of builds to perform in parallel.
35943 @item @code{max-allocated-builds} (default: @code{#f})
35944 The maximum number of builds this agent can be allocated.
35946 @item @code{max-1min-load-average} (default: @code{#f})
35947 Load average value to look at when considering starting new builds, if
35948 the 1 minute load average exceeds this value, the agent will wait before
35949 starting new builds.
35951 This will be unspecified if the value is @code{#f}, and the agent will
35952 use the number of cores reported by the system as the max 1 minute load
35955 @item @code{derivation-substitute-urls} (default: @code{#f})
35956 URLs from which to attempt to fetch substitutes for derivations, if the
35957 derivations aren't already available.
35959 @item @code{non-derivation-substitute-urls} (default: @code{#f})
35960 URLs from which to attempt to fetch substitutes for build inputs, if the
35961 input store items aren't already available.
35966 @deftp {Data Type} guix-build-coordinator-agent-password-auth
35967 Data type representing an agent authenticating with a coordinator via a
35972 The UUID of the agent. This should be generated by the coordinator
35973 process, stored in the coordinator database, and used by the intended
35976 @item @code{password}
35977 The password to use when connecting to the coordinator.
35982 @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
35983 Data type representing an agent authenticating with a coordinator via a
35984 UUID and password read from a file.
35988 The UUID of the agent. This should be generated by the coordinator
35989 process, stored in the coordinator database, and used by the intended
35992 @item @code{password-file}
35993 A file containing the password to use when connecting to the
35999 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
36000 Data type representing an agent authenticating with a coordinator via a
36001 dynamic auth token and agent name.
36004 @item @code{agent-name}
36005 Name of an agent, this is used to match up to an existing entry in the
36006 database if there is one. When no existing entry is found, a new entry
36007 is automatically added.
36010 Dynamic auth token, this is created and stored in the coordinator
36011 database, and is used by the agent to authenticate.
36016 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
36017 Data type representing an agent authenticating with a coordinator via a
36018 dynamic auth token read from a file and agent name.
36021 @item @code{agent-name}
36022 Name of an agent, this is used to match up to an existing entry in the
36023 database if there is one. When no existing entry is found, a new entry
36024 is automatically added.
36026 @item @code{token-file}
36027 File containing the dynamic auth token, this is created and stored in
36028 the coordinator database, and is used by the agent to authenticate.
36033 The Guix Build Coordinator package contains a script to query an
36034 instance of the Guix Data Service for derivations to build, and then
36035 submit builds for those derivations to the coordinator. The service
36036 type below assists in running this script. This is an additional tool
36037 that may be useful when building derivations contained within an
36038 instance of the Guix Data Service.
36040 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
36041 Service type for the
36042 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
36043 value must be a @code{guix-build-coordinator-queue-builds-configuration}
36047 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
36048 Data type representing the options to the queue builds from guix data
36052 @item @code{package} (default: @code{guix-build-coordinator})
36053 The Guix Build Coordinator package to use.
36055 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
36056 The system user to run the service as.
36058 @item @code{coordinator} (default: @code{"http://localhost:8746"})
36059 The URI to use when connecting to the coordinator.
36061 @item @code{systems} (default: @code{#f})
36062 The systems for which to fetch derivations to build.
36064 @item @code{systems-and-targets} (default: @code{#f})
36065 An association list of system and target pairs for which to fetch
36066 derivations to build.
36068 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
36069 The Guix Data Service instance from which to query to find out about
36070 derivations to build.
36072 @item @code{guix-data-service-build-server-id} (default: @code{#f})
36073 The Guix Data Service build server ID corresponding to the builds being
36074 submitted. Providing this speeds up the submitting of builds as
36075 derivations that have already been submitted can be skipped before
36076 asking the coordinator to build them.
36078 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
36079 A file to record which commits have been processed, to avoid needlessly
36080 processing them again if the service is restarted.
36085 @subsubheading Guix Data Service
36086 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
36087 and provides data about GNU Guix. This includes information about
36088 packages, derivations and lint warnings.
36090 The data is stored in a PostgreSQL database, and available through a web
36093 @defvar {Scheme Variable} guix-data-service-type
36094 Service type for the Guix Data Service. Its value must be a
36095 @code{guix-data-service-configuration} object. The service optionally
36096 extends the getmail service, as the guix-commits mailing list is used to
36097 find out about changes in the Guix git repository.
36100 @deftp {Data Type} guix-data-service-configuration
36101 Data type representing the configuration of the Guix Data Service.
36104 @item @code{package} (default: @code{guix-data-service})
36105 The Guix Data Service package to use.
36107 @item @code{user} (default: @code{"guix-data-service"})
36108 The system user to run the service as.
36110 @item @code{group} (default: @code{"guix-data-service"})
36111 The system group to run the service as.
36113 @item @code{port} (default: @code{8765})
36114 The port to bind the web service to.
36116 @item @code{host} (default: @code{"127.0.0.1"})
36117 The host to bind the web service to.
36119 @item @code{getmail-idle-mailboxes} (default: @code{#f})
36120 If set, this is the list of mailboxes that the getmail service will be
36121 configured to listen to.
36123 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
36124 If set, this is the @code{getmail-retriever-configuration} object with
36125 which to configure getmail to fetch mail from the guix-commits mailing
36128 @item @code{extra-options} (default: @var{'()})
36129 Extra command line options for @code{guix-data-service}.
36131 @item @code{extra-process-jobs-options} (default: @var{'()})
36132 Extra command line options for @code{guix-data-service-process-jobs}.
36137 @subsubheading Nar Herder
36138 The @uref{https://git.cbaines.net/guix/nar-herder/about/,Nar Herder} is
36139 a utility for managing a collection of nars.
36141 @defvar {Scheme Variable} nar-herder-type
36142 Service type for the Guix Data Service. Its value must be a
36143 @code{nar-herder-configuration} object. The service optionally
36144 extends the getmail service, as the guix-commits mailing list is used to
36145 find out about changes in the Guix git repository.
36148 @deftp {Data Type} nar-herder-configuration
36149 Data type representing the configuration of the Guix Data Service.
36152 @item @code{package} (default: @code{nar-herder})
36153 The Nar Herder package to use.
36155 @item @code{user} (default: @code{"nar-herder"})
36156 The system user to run the service as.
36158 @item @code{group} (default: @code{"nar-herder"})
36159 The system group to run the service as.
36161 @item @code{port} (default: @code{8734})
36162 The port to bind the server to.
36164 @item @code{host} (default: @code{"127.0.0.1"})
36165 The host to bind the server to.
36167 @item @code{mirror} (default: @code{#f})
36168 Optional URL of the other Nar Herder instance which should be mirrored.
36169 This means that this Nar Herder instance will download it's database,
36170 and keep it up to date.
36172 @item @code{database} (default: @code{"/var/lib/nar-herder/nar_herder.db"})
36173 Location for the database. If this Nar Herder instance is mirroring
36174 another, the database will be downloaded if it doesn't exist. If this
36175 Nar Herder instance isn't mirroring another, an empty database will be
36178 @item @code{database-dump} (default: @code{"/var/lib/nar-herder/nar_herder_dump.db"})
36179 Location of the database dump. This is created and regularly updated by
36180 taking a copy of the database. This is the version of the database that
36181 is available to download.
36183 @item @code{storage} (default: @code{#f})
36184 Optional location in which to store nars.
36186 @item @code{storage-limit} (default: @code{"none"})
36187 Limit in bytes for the nars stored in the storage location. This can
36188 also be set to ``none'' so that there is no limit.
36190 When the storage location exceeds this size, nars are removed according
36191 to the nar removal criteria.
36193 @item @code{storage-nar-removal-criteria} (default: @code{'()})
36194 Criteria used to remove nars from the storage location. These are used
36195 in conjunction with the storage limit.
36197 When the storage location exceeds the storage limit size, nars will be
36198 checked against the nar removal criteria and if any of the criteria
36199 match, they will be removed. This will continue until the storage
36200 location is below the storage limit size.
36202 Each criteria is specified by a string, then an equals sign, then
36203 another string. Currently, only one criteria is supported, checking if a
36204 nar is stored on another Nar Herder instance.
36206 @item @code{ttl} (default: @code{#f})
36207 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
36208 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
36209 days, @code{1m} means 1 month, and so on.
36211 This allows the user's Guix to keep substitute information in cache for
36214 @item @code{negative-ttl} (default: @code{#f})
36215 Similarly produce @code{Cache-Control} HTTP headers to advertise the
36216 time-to-live (TTL) of @emph{negative} lookups---missing store items, for
36217 which the HTTP 404 code is returned. By default, no negative TTL is
36220 @item @code{log-level} (default: @code{'DEBUG})
36221 Log level to use, specify a log level like @code{'INFO} to stop logging
36222 individual requests.
36227 @node Linux Services
36228 @subsection Linux Services
36231 @cindex out of memory killer
36233 @cindex early out of memory daemon
36234 @subsubheading Early OOM Service
36236 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
36237 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
36238 space and provides a more responsive and configurable alternative to the
36239 in-kernel OOM killer. It is useful to prevent the system from becoming
36240 unresponsive when it runs out of memory.
36242 @deffn {Scheme Variable} earlyoom-service-type
36243 The service type for running @command{earlyoom}, the Early OOM daemon.
36244 Its value must be a @code{earlyoom-configuration} object, described
36245 below. The service can be instantiated in its default configuration
36249 (service earlyoom-service-type)
36253 @deftp {Data Type} earlyoom-configuration
36254 This is the configuration record for the @code{earlyoom-service-type}.
36257 @item @code{earlyoom} (default: @var{earlyoom})
36258 The Earlyoom package to use.
36260 @item @code{minimum-available-memory} (default: @code{10})
36261 The threshold for the minimum @emph{available} memory, in percentages.
36263 @item @code{minimum-free-swap} (default: @code{10})
36264 The threshold for the minimum free swap memory, in percentages.
36266 @item @code{prefer-regexp} (default: @code{#f})
36267 A regular expression (as a string) to match the names of the processes
36268 that should be preferably killed.
36270 @item @code{avoid-regexp} (default: @code{#f})
36271 A regular expression (as a string) to match the names of the processes
36272 that should @emph{not} be killed.
36274 @item @code{memory-report-interval} (default: @code{0})
36275 The interval in seconds at which a memory report is printed. It is
36276 disabled by default.
36278 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
36279 A boolean indicating whether the positive adjustments set in
36280 @file{/proc/*/oom_score_adj} should be ignored.
36282 @item @code{show-debug-messages?} (default: @code{#f})
36283 A boolean indicating whether debug messages should be printed. The logs
36284 are saved at @file{/var/log/earlyoom.log}.
36286 @item @code{send-notification-command} (default: @code{#f})
36287 This can be used to provide a custom command used for sending
36293 @cindex kernel module loader
36294 @subsubheading Kernel Module Loader Service
36296 The kernel module loader service allows one to load loadable kernel
36297 modules at boot. This is especially useful for modules that don't
36298 autoload and need to be manually loaded, as is the case with
36301 @deffn {Scheme Variable} kernel-module-loader-service-type
36302 The service type for loading loadable kernel modules at boot with
36303 @command{modprobe}. Its value must be a list of strings representing
36304 module names. For example loading the drivers provided by
36305 @code{ddcci-driver-linux}, in debugging mode by passing some module
36306 parameters, can be done as follow:
36309 (use-modules (gnu) (gnu services))
36310 (use-package-modules linux)
36311 (use-service-modules linux)
36313 (define ddcci-config
36314 (plain-file "ddcci.conf"
36315 "options ddcci dyndbg delay=120"))
36319 (services (cons* (service kernel-module-loader-service-type
36320 '("ddcci" "ddcci_backlight"))
36321 (simple-service 'ddcci-config etc-service-type
36322 (list `("modprobe.d/ddcci.conf"
36325 (kernel-loadable-modules (list ddcci-driver-linux)))
36330 @cindex Platform Reliability, Availability and Serviceability daemon
36331 @subsubheading Rasdaemon Service
36333 The Rasdaemon service provides a daemon which monitors platform
36334 @acronym{RAS, Reliability@comma{} Availability@comma{} and Serviceability} reports from
36335 Linux kernel trace events, logging them to syslogd.
36337 Reliability, Availability and Serviceability is a concept used on servers meant
36338 to measure their robustness.
36340 @strong{Relability} is the probability that a system will produce correct
36344 @item Generally measured as Mean Time Between Failures (MTBF), and
36345 @item Enhanced by features that help to avoid, detect and repair hardware
36349 @strong{Availability} is the probability that a system is operational at a
36353 @item Generally measured as a percentage of downtime per a period of time, and
36354 @item Often uses mechanisms to detect and correct hardware faults in runtime.
36357 @strong{Serviceability} is the simplicity and speed with which a system can be
36358 repaired or maintained:
36361 @item Generally measured on Mean Time Between Repair (MTBR).
36365 Among the monitoring measures, the most usual ones include:
36368 @item CPU – detect errors at instruction execution and at L1/L2/L3 caches;
36369 @item Memory – add error correction logic (ECC) to detect and correct errors;
36370 @item I/O – add CRC checksums for transferred data;
36371 @item Storage – RAID, journal file systems, checksums, Self-Monitoring,
36372 Analysis and Reporting Technology (SMART).
36375 By monitoring the number of occurrences of error detections, it is possible to
36376 identify if the probability of hardware errors is increasing, and, on such
36377 case, do a preventive maintenance to replace a degraded component while those
36378 errors are correctable.
36380 For detailed information about the types of error events gathered and how to
36381 make sense of them, see the kernel administrator's guide at
36382 @url{https://www.kernel.org/doc/html/latest/admin-guide/ras.html}.
36384 @defvr {Scheme Variable} rasdaemon-service-type
36385 Service type for the @command{rasdaemon} service. It accepts a
36386 @code{rasdaemon-configuration} object. Instantiating like
36389 (service rasdaemon-service-type)
36392 will load with a default configuration, which monitors all events and logs to
36396 @deftp {Data Type} rasdaemon-configuration
36397 The data type representing the configuration of @command{rasdaemon}.
36400 @item @code{record?} (default: @code{#f})
36402 A boolean indicating whether to record the events in an SQLite database. This
36403 provides a more structured access to the information contained in the log file.
36404 The database location is hard-coded to @file{/var/lib/rasdaemon/ras-mc_event.db}.
36410 @cindex compressed swap
36411 @cindex Compressed RAM-based block devices
36412 @subsubheading Zram Device Service
36414 The Zram device service provides a compressed swap device in system
36415 memory. The Linux Kernel documentation has more information about
36416 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
36419 @deffn {Scheme Variable} zram-device-service-type
36420 This service creates the zram block device, formats it as swap and
36421 enables it as a swap device. The service's value is a
36422 @code{zram-device-configuration} record.
36424 @deftp {Data Type} zram-device-configuration
36425 This is the data type representing the configuration for the zram-device
36429 @item @code{size} (default @code{"1G"})
36430 This is the amount of space you wish to provide for the zram device. It
36431 accepts a string and can be a number of bytes or use a suffix, eg.:
36432 @code{"512M"} or @code{1024000}.
36433 @item @code{compression-algorithm} (default @code{'lzo})
36434 This is the compression algorithm you wish to use. It is difficult to
36435 list all the possible compression options, but common ones supported by
36436 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
36437 @item @code{memory-limit} (default @code{0})
36438 This is the maximum amount of memory which the zram device can use.
36439 Setting it to '0' disables the limit. While it is generally expected
36440 that compression will be 2:1, it is possible that uncompressable data
36441 can be written to swap and this is a method to limit how much memory can
36442 be used. It accepts a string and can be a number of bytes or use a
36443 suffix, eg.: @code{"2G"}.
36444 @item @code{priority} (default @code{#f})
36445 This is the priority of the swap device created from the zram device.
36446 @xref{Swap Space} for a description of swap priorities. You might want
36447 to set a specific priority for the zram device, otherwise it could end
36448 up not being used much for the reasons described there.
36454 @node Hurd Services
36455 @subsection Hurd Services
36457 @defvr {Scheme Variable} hurd-console-service-type
36458 This service starts the fancy @code{VGA} console client on the Hurd.
36460 The service's value is a @code{hurd-console-configuration} record.
36463 @deftp {Data Type} hurd-console-configuration
36464 This is the data type representing the configuration for the
36465 hurd-console-service.
36468 @item @code{hurd} (default: @var{hurd})
36469 The Hurd package to use.
36473 @defvr {Scheme Variable} hurd-getty-service-type
36474 This service starts a tty using the Hurd @code{getty} program.
36476 The service's value is a @code{hurd-getty-configuration} record.
36479 @deftp {Data Type} hurd-getty-configuration
36480 This is the data type representing the configuration for the
36481 hurd-getty-service.
36484 @item @code{hurd} (default: @var{hurd})
36485 The Hurd package to use.
36488 The name of the console this Getty runs on---e.g., @code{"tty1"}.
36490 @item @code{baud-rate} (default: @code{38400})
36491 An integer specifying the baud rate of the tty.
36496 @node Miscellaneous Services
36497 @subsection Miscellaneous Services
36499 @cindex fingerprint
36500 @subsubheading Fingerprint Service
36502 The @code{(gnu services authentication)} module provides a DBus service to
36503 read and identify fingerprints via a fingerprint sensor.
36505 @defvr {Scheme Variable} fprintd-service-type
36506 The service type for @command{fprintd}, which provides the fingerprint
36507 reading capability.
36510 (service fprintd-service-type)
36515 @subsubheading System Control Service
36517 The @code{(gnu services sysctl)} provides a service to configure kernel
36518 parameters at boot.
36520 @defvr {Scheme Variable} sysctl-service-type
36521 The service type for @command{sysctl}, which modifies kernel parameters
36522 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
36526 (service sysctl-service-type
36527 (sysctl-configuration
36528 (settings '(("net.ipv4.ip_forward" . "1")))))
36531 Since @code{sysctl-service-type} is used in the default lists of
36532 services, @code{%base-services} and @code{%desktop-services}, you can
36533 use @code{modify-services} to change its configuration and add the
36534 kernel parameters that you want (@pxref{Service Reference,
36535 @code{modify-services}}).
36538 (modify-services %base-services
36539 (sysctl-service-type config =>
36540 (sysctl-configuration
36541 (settings (append '(("net.ipv4.ip_forward" . "1"))
36542 %default-sysctl-settings)))))
36547 @deftp {Data Type} sysctl-configuration
36548 The data type representing the configuration of @command{sysctl}.
36551 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
36552 The @command{sysctl} executable to use.
36554 @item @code{settings} (default: @code{%default-sysctl-settings})
36555 An association list specifies kernel parameters and their values.
36559 @defvr {Scheme Variable} %default-sysctl-settings
36560 An association list specifying the default @command{sysctl} parameters
36565 @subsubheading PC/SC Smart Card Daemon Service
36567 The @code{(gnu services security-token)} module provides the following service
36568 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
36569 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
36570 manager that coordinates communications with smart card readers, smart cards
36571 and cryptographic tokens that are connected to the system.
36573 @defvr {Scheme Variable} pcscd-service-type
36574 Service type for the @command{pcscd} service. Its value must be a
36575 @code{pcscd-configuration} object. To run pcscd in the default
36576 configuration, instantiate it as:
36579 (service pcscd-service-type)
36583 @deftp {Data Type} pcscd-configuration
36584 The data type representing the configuration of @command{pcscd}.
36587 @item @code{pcsc-lite} (default: @code{pcsc-lite})
36588 The pcsc-lite package that provides pcscd.
36589 @item @code{usb-drivers} (default: @code{(list ccid)})
36590 List of packages that provide USB drivers to pcscd. Drivers are expected to be
36591 under @file{pcsc/drivers} in the store directory of the package.
36596 @subsubheading Lirc Service
36598 The @code{(gnu services lirc)} module provides the following service.
36600 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
36601 [#:device #f] [#:driver #f] [#:config-file #f] @
36602 [#:extra-options '()]
36603 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
36604 decodes infrared signals from remote controls.
36606 Optionally, @var{device}, @var{driver} and @var{config-file}
36607 (configuration file name) may be specified. See @command{lircd} manual
36610 Finally, @var{extra-options} is a list of additional command-line options
36611 passed to @command{lircd}.
36615 @subsubheading Spice Service
36617 The @code{(gnu services spice)} module provides the following service.
36619 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
36620 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
36621 that enables sharing the clipboard with a vm and setting the guest display
36622 resolution when the graphical console window resizes.
36625 @cindex inputattach
36626 @subsubheading inputattach Service
36628 @cindex tablet input, for Xorg
36629 @cindex touchscreen input, for Xorg
36630 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
36631 use input devices such as Wacom tablets, touchscreens, or joysticks with the
36632 Xorg display server.
36634 @deffn {Scheme Variable} inputattach-service-type
36635 Type of a service that runs @command{inputattach} on a device and
36636 dispatches events from it.
36639 @deftp {Data Type} inputattach-configuration
36641 @item @code{device-type} (default: @code{"wacom"})
36642 The type of device to connect to. Run @command{inputattach --help}, from the
36643 @code{inputattach} package, to see the list of supported device types.
36645 @item @code{device} (default: @code{"/dev/ttyS0"})
36646 The device file to connect to the device.
36648 @item @code{baud-rate} (default: @code{#f})
36649 Baud rate to use for the serial connection.
36650 Should be a number or @code{#f}.
36652 @item @code{log-file} (default: @code{#f})
36653 If true, this must be the name of a file to log messages to.
36657 @subsubheading Dictionary Service
36659 The @code{(gnu services dict)} module provides the following service:
36661 @defvr {Scheme Variable} dicod-service-type
36662 This is the type of the service that runs the @command{dicod} daemon, an
36663 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
36666 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
36667 Return a service that runs the @command{dicod} daemon, an implementation
36668 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
36670 The optional @var{config} argument specifies the configuration for
36671 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
36672 default it serves the GNU Collaborative International Dictionary of English.
36674 You can add @command{open localhost} to your @file{~/.dico} file to make
36675 @code{localhost} the default server for @command{dico} client
36676 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
36679 @deftp {Data Type} dicod-configuration
36680 Data type representing the configuration of dicod.
36683 @item @code{dico} (default: @var{dico})
36684 Package object of the GNU Dico dictionary server.
36686 @item @code{interfaces} (default: @var{'("localhost")})
36687 This is the list of IP addresses and ports and possibly socket file
36688 names to listen to (@pxref{Server Settings, @code{listen} directive,,
36689 dico, GNU Dico Manual}).
36691 @item @code{handlers} (default: @var{'()})
36692 List of @code{<dicod-handler>} objects denoting handlers (module instances).
36694 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
36695 List of @code{<dicod-database>} objects denoting dictionaries to be served.
36699 @deftp {Data Type} dicod-handler
36700 Data type representing a dictionary handler (module instance).
36704 Name of the handler (module instance).
36706 @item @code{module} (default: @var{#f})
36707 Name of the dicod module of the handler (instance). If it is @code{#f},
36708 the module has the same name as the handler.
36709 (@pxref{Modules,,, dico, GNU Dico Manual}).
36711 @item @code{options}
36712 List of strings or gexps representing the arguments for the module handler
36716 @deftp {Data Type} dicod-database
36717 Data type representing a dictionary database.
36721 Name of the database, will be used in DICT commands.
36723 @item @code{handler}
36724 Name of the dicod handler (module instance) used by this database
36725 (@pxref{Handlers,,, dico, GNU Dico Manual}).
36727 @item @code{complex?} (default: @var{#f})
36728 Whether the database configuration complex. The complex configuration
36729 will need a corresponding @code{<dicod-handler>} object, otherwise not.
36731 @item @code{options}
36732 List of strings or gexps representing the arguments for the database
36733 (@pxref{Databases,,, dico, GNU Dico Manual}).
36737 @defvr {Scheme Variable} %dicod-database:gcide
36738 A @code{<dicod-database>} object serving the GNU Collaborative International
36739 Dictionary of English using the @code{gcide} package.
36742 The following is an example @code{dicod-service} configuration.
36745 (dicod-service #:config
36746 (dicod-configuration
36747 (handlers (list (dicod-handler
36751 (list #~(string-append "dbdir=" #$wordnet))))))
36752 (databases (list (dicod-database
36755 (handler "wordnet")
36756 (options '("database=wn")))
36757 %dicod-database:gcide))))
36761 @subsubheading Docker Service
36763 The @code{(gnu services docker)} module provides the following services.
36765 @defvr {Scheme Variable} docker-service-type
36767 This is the type of the service that runs @url{https://www.docker.com,Docker},
36768 a daemon that can execute application bundles (sometimes referred to as
36769 ``containers'') in isolated environments.
36773 @deftp {Data Type} docker-configuration
36774 This is the data type representing the configuration of Docker and Containerd.
36778 @item @code{docker} (default: @code{docker})
36779 The Docker daemon package to use.
36781 @item @code{docker-cli} (default: @code{docker-cli})
36782 The Docker client package to use.
36784 @item @code{containerd} (default: @var{containerd})
36785 The Containerd package to use.
36787 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
36788 The Docker user-land networking proxy package to use.
36790 @item @code{enable-proxy?} (default @code{#t})
36791 Enable or disable the use of the Docker user-land networking proxy.
36793 @item @code{debug?} (default @code{#f})
36794 Enable or disable debug output.
36796 @item @code{enable-iptables?} (default @code{#t})
36797 Enable or disable the addition of iptables rules.
36799 @item @code{environment-variables} (default: @code{()})
36800 List of environment variables to set for @command{dockerd}.
36802 This must be a list of strings where each string has the form
36803 @samp{@var{key}=@var{value}} as in this example:
36806 (list "LANGUAGE=eo:ca:eu"
36807 "TMPDIR=/tmp/dockerd")
36813 @cindex Singularity, container service
36814 @defvr {Scheme Variable} singularity-service-type
36815 This is the type of the service that allows you to run
36816 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
36817 create and run application bundles (aka. ``containers''). The value for this
36818 service is the Singularity package to use.
36820 The service does not install a daemon; instead, it installs helper programs as
36821 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
36822 @command{singularity run} and similar commands.
36826 @subsubheading Auditd Service
36828 The @code{(gnu services auditd)} module provides the following service.
36830 @defvr {Scheme Variable} auditd-service-type
36832 This is the type of the service that runs
36833 @url{https://people.redhat.com/sgrubb/audit/,auditd},
36834 a daemon that tracks security-relevant information on your system.
36836 Examples of things that can be tracked:
36846 Failed login attempts
36853 @command{auditctl} from the @code{audit} package can be used in order
36854 to add or remove events to be tracked (until the next reboot).
36855 In order to permanently track events, put the command line arguments
36856 of auditctl into a file called @code{audit.rules} in the configuration
36857 directory (see below).
36858 @command{aureport} from the @code{audit} package can be used in order
36859 to view a report of all recorded events.
36860 The audit daemon by default logs into the file
36861 @file{/var/log/audit.log}.
36865 @deftp {Data Type} auditd-configuration
36866 This is the data type representing the configuration of auditd.
36870 @item @code{audit} (default: @code{audit})
36871 The audit package to use.
36873 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
36874 The directory containing the configuration file for the audit package, which
36875 must be named @code{auditd.conf}, and optionally some audit rules to
36876 instantiate on startup.
36882 @subsubheading R-Shiny service
36884 The @code{(gnu services science)} module provides the following service.
36886 @defvr {Scheme Variable} rshiny-service-type
36888 This is a type of service which is used to run a webapp created with
36889 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
36890 variable and runs the provided script to call @code{runApp}.
36892 @deftp {Data Type} rshiny-configuration
36893 This is the data type representing the configuration of rshiny.
36897 @item @code{package} (default: @code{r-shiny})
36898 The package to use.
36900 @item @code{binary} (default @code{"rshiny"})
36901 The name of the binary or shell script located at @code{package/bin/} to
36902 run when the service is run.
36904 The common way to create this file is as follows:
36908 (let* ((out (assoc-ref %outputs "out"))
36909 (targetdir (string-append out "/share/" ,name))
36910 (app (string-append out "/bin/" ,name))
36911 (Rbin (search-input-file %build-inputs "/bin/Rscript")))
36913 (mkdir-p (string-append out "/bin"))
36914 (call-with-output-file app
36920 runApp(launch.browser=0, port=4202)~%\n"
36929 @subsubheading Nix service
36931 The @code{(gnu services nix)} module provides the following service.
36933 @defvr {Scheme Variable} nix-service-type
36935 This is the type of the service that runs build daemon of the
36936 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
36940 (use-modules (gnu))
36941 (use-service-modules nix)
36942 (use-package-modules package-management)
36946 (packages (append (list nix)
36949 (services (append (list (service nix-service-type))
36953 After @command{guix system reconfigure} configure Nix for your user:
36956 @item Add a Nix channel and update it. See
36957 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
36959 @item Create a symlink to your profile and activate Nix profile:
36963 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
36964 $ source /run/current-system/profile/etc/profile.d/nix.sh
36969 @deftp {Data Type} nix-configuration
36970 This data type represents the configuration of the Nix daemon.
36973 @item @code{nix} (default: @code{nix})
36974 The Nix package to use.
36976 @item @code{sandbox} (default: @code{#t})
36977 Specifies whether builds are sandboxed by default.
36979 @item @code{build-sandbox-items} (default: @code{'()})
36980 This is a list of strings or objects appended to the
36981 @code{build-sandbox-items} field of the configuration file.
36983 @item @code{extra-config} (default: @code{'()})
36984 This is a list of strings or objects appended to the configuration file.
36985 It is used to pass extra text to be added verbatim to the configuration
36988 @item @code{extra-options} (default: @code{'()})
36989 Extra command line options for @code{nix-service-type}.
36994 @subsubheading Fail2Ban service
36996 @uref{http://www.fail2ban.org/, @code{fail2ban}} scans log files
36997 (e.g. @code{/var/log/apache/error_log}) and bans IP addresses that show
36998 malicious signs -- repeated password failures, attempts to make use of
37001 @code{fail2ban-service-type} service type is provided by the @code{(gnu
37002 services security)} module.
37004 This service type runs the @code{fail2ban} daemon. It can be configured
37005 in various ways, which are:
37008 @item Basic configuration
37009 The basic parameters of the Fail2Ban service can be configured via its
37010 @code{fail2ban} configuration, which is documented below.
37012 @item User-specified jail extensions
37013 The @code{fail2ban-jail-service} function can be used to add new
37016 @item Shepherd extension mechanism
37017 Service developers can extend the @code{fail2ban-service-type} service
37018 type itself via the usual service extension mechanism.
37021 @defvr {Scheme Variable} fail2ban-service-type
37023 This is the type of the service that runs @code{fail2ban} daemon. Below
37024 is an example of a basic, explicit configuration:
37029 (service fail2ban-service-type
37030 (fail2ban-configuration
37033 (fail2ban-jail-configuration
37036 ;; There is no implicit dependency on an actual SSH
37037 ;; service, so you need to provide one.
37038 (service openssh-service-type))
37043 @deffn {Scheme Procedure} fail2ban-jail-service @var{svc-type} @var{jail}
37044 Extend @var{svc-type}, a @code{<service-type>} object with @var{jail}, a
37045 @code{fail2ban-jail-configuration} object.
37053 ;; The 'fail2ban-jail-service' procedure can extend any service type
37054 ;; with a fail2ban jail. This removes the requirement to explicitly
37055 ;; extend services with fail2ban-service-type.
37056 (fail2ban-jail-service
37057 openssh-service-type
37058 (fail2ban-jail-configuration
37061 (openssh-configuration ...))))
37065 Below is the reference for the different @code{jail-service-type}
37066 configuration records.
37068 @c The documentation is to be auto-generated via
37069 @c 'generate-documentation'. See at the bottom of (gnu services
37072 @deftp {Data Type} fail2ban-configuration
37073 Available @code{fail2ban-configuration} fields are:
37076 @item @code{fail2ban} (default: @code{fail2ban}) (type: package)
37077 The @code{fail2ban} package to use. It is used for both binaries and as
37078 base default configuration that is to be extended with
37079 @code{<fail2ban-jail-configuration>} objects.
37081 @item @code{run-directory} (default: @code{"/var/run/fail2ban"}) (type: string)
37082 The state directory for the @code{fail2ban} daemon.
37084 @item @code{jails} (default: @code{()}) (type: list-of-fail2ban-jail-configurations)
37085 Instances of @code{<fail2ban-jail-configuration>} collected from
37088 @item @code{extra-jails} (default: @code{()}) (type: list-of-fail2ban-jail-configurations)
37089 Instances of @code{<fail2ban-jail-configuration>} explicitly provided.
37091 @item @code{extra-content} (default: @code{()}) (type: text-config)
37092 Extra raw content to add to the end of the @file{jail.local} file,
37093 provided as a list of file-like objects.
37099 @deftp {Data Type} fail2ban-ignore-cache-configuration
37100 Available @code{fail2ban-ignore-cache-configuration} fields are:
37103 @item @code{key} (type: string)
37106 @item @code{max-count} (type: integer)
37109 @item @code{max-time} (type: integer)
37116 @deftp {Data Type} fail2ban-jail-action-configuration
37117 Available @code{fail2ban-jail-action-configuration} fields are:
37120 @item @code{name} (type: string)
37123 @item @code{arguments} (default: @code{()}) (type: list-of-arguments)
37130 @deftp {Data Type} fail2ban-jail-configuration
37131 Available @code{fail2ban-jail-configuration} fields are:
37134 @item @code{name} (type: string)
37135 Required name of this jail configuration.
37137 @item @code{enabled?} (default: @code{#t}) (type: boolean)
37138 Whether this jail is enabled.
37140 @item @code{backend} (type: maybe-symbol)
37141 Backend to use to detect changes in the @code{log-path}. The default is
37142 'auto. To consult the defaults of the jail configuration, refer to the
37143 @file{/etc/fail2ban/jail.conf} file of the @code{fail2ban} package.
37145 @item @code{max-retry} (type: maybe-integer)
37146 The number of failures before a host get banned (e.g. @code{(max-retry
37149 @item @code{max-matches} (type: maybe-integer)
37150 The number of matches stored in ticket (resolvable via tag
37151 @code{<matches>}) in action.
37153 @item @code{find-time} (type: maybe-string)
37154 The time window during which the maximum retry count must be reached for
37155 an IP address to be banned. A host is banned if it has generated
37156 @code{max-retry} during the last @code{find-time} seconds (e.g.
37157 @code{(find-time "10m")}). It can be provided in seconds or using
37158 Fail2Ban's "time abbreviation format", as described in @command{man 5
37161 @item @code{ban-time} (type: maybe-string)
37162 The duration, in seconds or time abbreviated format, that a ban should
37163 last. (e.g. @code{(ban-time "10m")}).
37165 @item @code{ban-time-increment?} (type: maybe-boolean)
37166 Whether to consider past bans to compute increases to the default ban
37167 time of a specific IP address.
37169 @item @code{ban-time-factor} (type: maybe-string)
37170 The coefficient to use to compute an exponentially growing ban time.
37172 @item @code{ban-time-formula} (type: maybe-string)
37173 This is the formula used to calculate the next value of a ban time.
37175 @item @code{ban-time-multipliers} (type: maybe-string)
37176 Used to calculate next value of ban time instead of formula.
37178 @item @code{ban-time-max-time} (type: maybe-string)
37179 The maximum number of seconds a ban should last.
37181 @item @code{ban-time-rnd-time} (type: maybe-string)
37182 The maximum number of seconds a randomized ban time should last. This
37183 can be useful to stop ``clever'' botnets calculating the exact time an
37184 IP address can be unbanned again.
37186 @item @code{ban-time-overall-jails?} (type: maybe-boolean)
37187 When true, it specifies the search of an IP address in the database
37188 should be made across all jails. Otherwise, only the current jail of
37189 the ban IP address is considered.
37191 @item @code{ignore-self?} (type: maybe-boolean)
37192 Never ban the local machine's own IP address.
37194 @item @code{ignore-ip} (default: @code{()}) (type: list-of-strings)
37195 A list of IP addresses, CIDR masks or DNS hosts to ignore.
37196 @code{fail2ban} will not ban a host which matches an address in this
37199 @item @code{ignore-cache} (type: maybe-fail2ban-ignore-cache-configuration)
37200 Provide cache parameters for the ignore failure check.
37202 @item @code{filter} (type: maybe-fail2ban-jail-filter-configuration)
37203 The filter to use by the jail, specified via a
37204 @code{<fail2ban-jail-filter-configuration>} object. By default, jails
37205 have names matching their filter name.
37207 @item @code{log-time-zone} (type: maybe-string)
37208 The default time zone for log lines that do not have one.
37210 @item @code{log-encoding} (type: maybe-symbol)
37211 The encoding of the log files handled by the jail. Possible values are:
37212 @code{'ascii}, @code{'utf-8} and @code{'auto}.
37214 @item @code{log-path} (default: @code{()}) (type: list-of-strings)
37215 The file names of the log files to be monitored.
37217 @item @code{action} (default: @code{()}) (type: list-of-fail2ban-jail-actions)
37218 A list of @code{<fail2ban-jail-action-configuration>}.
37220 @item @code{extra-content} (default: @code{()}) (type: text-config)
37221 Extra content for the jail configuration, provided as a list of file-like
37228 @deftp {Data Type} fail2ban-jail-filter-configuration
37229 Available @code{fail2ban-jail-filter-configuration} fields are:
37232 @item @code{name} (type: string)
37235 @item @code{mode} (type: maybe-string)
37242 @c End of auto-generated fail2ban documentation.
37244 @node Setuid Programs
37245 @section Setuid Programs
37247 @cindex setuid programs
37248 @cindex setgid programs
37249 Some programs need to run with elevated privileges, even when they are
37250 launched by unprivileged users. A notorious example is the
37251 @command{passwd} program, which users can run to change their
37252 password, and which needs to access the @file{/etc/passwd} and
37253 @file{/etc/shadow} files---something normally restricted to root, for
37254 obvious security reasons. To address that, @command{passwd} should be
37255 @dfn{setuid-root}, meaning that it always runs with root privileges
37256 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
37257 for more info about the setuid mechanism).
37259 The store itself @emph{cannot} contain setuid programs: that would be a
37260 security issue since any user on the system can write derivations that
37261 populate the store (@pxref{The Store}). Thus, a different mechanism is
37262 used: instead of changing the setuid or setgid bits directly on files that
37263 are in the store, we let the system administrator @emph{declare} which
37264 programs should be entrusted with these additional privileges.
37266 The @code{setuid-programs} field of an @code{operating-system}
37267 declaration contains a list of @code{<setuid-program>} denoting the
37268 names of programs to have a setuid or setgid bit set (@pxref{Using the
37269 Configuration System}). For instance, the @command{mount.nfs} program,
37270 which is part of the nfs-utils package, with a setuid root can be
37271 designated like this:
37275 (program (file-append nfs-utils "/sbin/mount.nfs")))
37278 And then, to make @command{mount.nfs} setuid on your system, add the
37279 previous example to your operating system declaration by appending it to
37280 @code{%setuid-programs} like this:
37284 ;; Some fields omitted...
37286 (append (list (setuid-program
37287 (program (file-append nfs-utils "/sbin/mount.nfs"))))
37288 %setuid-programs)))
37291 @deftp {Data Type} setuid-program
37292 This data type represents a program with a setuid or setgid bit set.
37295 @item @code{program}
37296 A file-like object having its setuid and/or setgid bit set.
37298 @item @code{setuid?} (default: @code{#t})
37299 Whether to set user setuid bit.
37301 @item @code{setgid?} (default: @code{#f})
37302 Whether to set group setgid bit.
37304 @item @code{user} (default: @code{0})
37305 UID (integer) or user name (string) for the user owner of the program,
37308 @item @code{group} (default: @code{0})
37309 GID (integer) goup name (string) for the group owner of the program,
37315 A default set of setuid programs is defined by the
37316 @code{%setuid-programs} variable of the @code{(gnu system)} module.
37318 @defvr {Scheme Variable} %setuid-programs
37319 A list of @code{<setuid-program>} denoting common programs that are
37322 The list includes commands such as @command{passwd}, @command{ping},
37323 @command{su}, and @command{sudo}.
37326 Under the hood, the actual setuid programs are created in the
37327 @file{/run/setuid-programs} directory at system activation time. The
37328 files in this directory refer to the ``real'' binaries, which are in the
37331 @node X.509 Certificates
37332 @section X.509 Certificates
37334 @cindex HTTPS, certificates
37335 @cindex X.509 certificates
37337 Web servers available over HTTPS (that is, HTTP over the transport-layer
37338 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
37339 that the client can then use to @emph{authenticate} the server. To do
37340 that, clients verify that the server's certificate is signed by a
37341 so-called @dfn{certificate authority} (CA). But to verify the CA's
37342 signature, clients must have first acquired the CA's certificate.
37344 Web browsers such as GNU@tie{}IceCat include their own set of CA
37345 certificates, such that they are able to verify CA signatures
37348 However, most other programs that can talk HTTPS---@command{wget},
37349 @command{git}, @command{w3m}, etc.---need to be told where CA
37350 certificates can be found.
37352 @cindex @code{nss-certs}
37353 In Guix, this is done by adding a package that provides certificates
37354 to the @code{packages} field of the @code{operating-system} declaration
37355 (@pxref{operating-system Reference}). Guix includes one such package,
37356 @code{nss-certs}, which is a set of CA certificates provided as part of
37357 Mozilla's Network Security Services.
37359 Note that it is @emph{not} part of @code{%base-packages}, so you need to
37360 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
37361 most applications and libraries look for certificates by default, points
37362 to the certificates installed globally.
37364 Unprivileged users, including users of Guix on a foreign distro,
37365 can also install their own certificate package in
37366 their profile. A number of environment variables need to be defined so
37367 that applications and libraries know where to find them. Namely, the
37368 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
37369 variables. Some applications add their own environment variables; for
37370 instance, the Git version control system honors the certificate bundle
37371 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
37372 would typically run something like:
37375 guix install nss-certs
37376 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
37377 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
37378 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
37381 As another example, R requires the @env{CURL_CA_BUNDLE} environment
37382 variable to point to a certificate bundle, so you would have to run
37383 something like this:
37386 guix install nss-certs
37387 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
37390 For other applications you may want to look up the required environment
37391 variable in the relevant documentation.
37394 @node Name Service Switch
37395 @section Name Service Switch
37397 @cindex name service switch
37399 The @code{(gnu system nss)} module provides bindings to the
37400 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
37401 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
37402 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
37403 extended with new ``name'' lookup methods for system databases, which
37404 includes host names, service names, user accounts, and more (@pxref{Name
37405 Service Switch, System Databases and Name Service Switch,, libc, The GNU
37406 C Library Reference Manual}).
37408 The NSS configuration specifies, for each system database, which lookup
37409 method is to be used, and how the various methods are chained
37410 together---for instance, under which circumstances NSS should try the
37411 next method in the list. The NSS configuration is given in the
37412 @code{name-service-switch} field of @code{operating-system} declarations
37413 (@pxref{operating-system Reference, @code{name-service-switch}}).
37416 @cindex .local, host name lookup
37417 As an example, the declaration below configures the NSS to use the
37418 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
37419 back-end}, which supports host name lookups over multicast DNS (mDNS)
37420 for host names ending in @code{.local}:
37423 (name-service-switch
37424 (hosts (list %files ;first, check /etc/hosts
37426 ;; If the above did not succeed, try
37427 ;; with 'mdns_minimal'.
37429 (name "mdns_minimal")
37431 ;; 'mdns_minimal' is authoritative for
37432 ;; '.local'. When it returns "not found",
37433 ;; no need to try the next methods.
37434 (reaction (lookup-specification
37435 (not-found => return))))
37437 ;; Then fall back to DNS.
37441 ;; Finally, try with the "full" 'mdns'.
37446 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
37447 contains this configuration, so you will not have to type it if all you
37448 want is to have @code{.local} host lookup working.
37450 Note that, in this case, in addition to setting the
37451 @code{name-service-switch} of the @code{operating-system} declaration,
37452 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
37453 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
37454 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
37455 to the name service cache daemon (@pxref{Base Services,
37456 @code{nscd-service}}).
37458 For convenience, the following variables provide typical NSS
37461 @defvr {Scheme Variable} %default-nss
37462 This is the default name service switch configuration, a
37463 @code{name-service-switch} object.
37466 @defvr {Scheme Variable} %mdns-host-lookup-nss
37467 This is the name service switch configuration with support for host name
37468 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
37471 The reference for name service switch configuration is given below. It
37472 is a direct mapping of the configuration file format of the C library , so
37473 please refer to the C library manual for more information (@pxref{NSS
37474 Configuration File,,, libc, The GNU C Library Reference Manual}).
37475 Compared to the configuration file format of libc NSS, it has the advantage
37476 not only of adding this warm parenthetic feel that we like, but also
37477 static checks: you will know about syntax errors and typos as soon as you
37478 run @command{guix system}.
37480 @deftp {Data Type} name-service-switch
37482 This is the data type representation the configuration of libc's name
37483 service switch (NSS). Each field below represents one of the supported
37500 The system databases handled by the NSS@. Each of these fields must be a
37501 list of @code{<name-service>} objects (see below).
37505 @deftp {Data Type} name-service
37507 This is the data type representing an actual name service and the
37508 associated lookup action.
37512 A string denoting the name service (@pxref{Services in the NSS
37513 configuration,,, libc, The GNU C Library Reference Manual}).
37515 Note that name services listed here must be visible to nscd. This is
37516 achieved by passing the @code{#:name-services} argument to
37517 @code{nscd-service} the list of packages providing the needed name
37518 services (@pxref{Base Services, @code{nscd-service}}).
37521 An action specified using the @code{lookup-specification} macro
37522 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
37523 Reference Manual}). For example:
37526 (lookup-specification (unavailable => continue)
37527 (success => return))
37532 @node Initial RAM Disk
37533 @section Initial RAM Disk
37536 @cindex initial RAM disk
37537 For bootstrapping purposes, the Linux-Libre kernel is passed an
37538 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
37539 root file system as well as an initialization script. The latter is
37540 responsible for mounting the real root file system, and for loading any
37541 kernel modules that may be needed to achieve that.
37543 The @code{initrd-modules} field of an @code{operating-system}
37544 declaration allows you to specify Linux-libre kernel modules that must
37545 be available in the initrd. In particular, this is where you would list
37546 modules needed to actually drive the hard disk where your root partition
37547 is---although the default value of @code{initrd-modules} should cover
37548 most use cases. For example, assuming you need the @code{megaraid_sas}
37549 module in addition to the default modules to be able to access your root
37550 file system, you would write:
37555 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
37558 @defvr {Scheme Variable} %base-initrd-modules
37559 This is the list of kernel modules included in the initrd by default.
37562 Furthermore, if you need lower-level customization, the @code{initrd}
37563 field of an @code{operating-system} declaration allows
37564 you to specify which initrd you would like to use. The @code{(gnu
37565 system linux-initrd)} module provides three ways to build an initrd: the
37566 high-level @code{base-initrd} procedure and the low-level
37567 @code{raw-initrd} and @code{expression->initrd} procedures.
37569 The @code{base-initrd} procedure is intended to cover most common uses.
37570 For example, if you want to add a bunch of kernel modules to be loaded
37571 at boot time, you can define the @code{initrd} field of the operating
37572 system declaration like this:
37575 (initrd (lambda (file-systems . rest)
37576 ;; Create a standard initrd but set up networking
37577 ;; with the parameters QEMU expects by default.
37578 (apply base-initrd file-systems
37579 #:qemu-networking? #t
37583 The @code{base-initrd} procedure also handles common use cases that
37584 involves using the system as a QEMU guest, or as a ``live'' system with
37585 volatile root file system.
37587 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
37588 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
37589 such as trying to guess which kernel modules and packages should be included
37590 to the initrd. An example use of @code{raw-initrd} is when a user has
37591 a custom Linux kernel configuration and default kernel modules included by
37592 @code{base-initrd} are not available.
37594 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
37595 honors several options passed on the Linux kernel command line
37596 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
37597 @code{-append} option of QEMU), notably:
37600 @item gnu.load=@var{boot}
37601 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
37602 program, once it has mounted the root file system.
37604 Guix uses this option to yield control to a boot program that runs the
37605 service activation programs and then spawns the GNU@tie{}Shepherd, the
37606 initialization system.
37608 @item root=@var{root}
37609 Mount @var{root} as the root file system. @var{root} can be a device
37610 name like @code{/dev/sda1}, a file system label, or a file system UUID.
37611 When unspecified, the device name from the root file system of the
37612 operating system declaration is used.
37614 @item rootfstype=@var{type}
37615 Set the type of the root file system. It overrides the @code{type}
37616 field of the root file system specified via the @code{operating-system}
37617 declaration, if any.
37619 @item rootflags=@var{options}
37620 Set the mount @emph{options} of the root file system. It overrides the
37621 @code{options} field of the root file system specified via the
37622 @code{operating-system} declaration, if any.
37624 @item fsck.mode=@var{mode}
37625 Whether to check the @var{root} file system for errors before mounting
37626 it. @var{mode} is one of @code{skip} (never check), @code{force} (always
37627 check), or @code{auto} to respect the root @code{<file-system>} object's
37628 @code{check?} setting (@pxref{File Systems}) and run a full scan only if
37629 the file system was not cleanly shut down.
37631 @code{auto} is the default if this option is not present or if @var{mode}
37632 is not one of the above.
37634 @item fsck.repair=@var{level}
37635 The level of repairs to perform automatically if errors are found in the
37636 @var{root} file system. @var{level} is one of @code{no} (do not write to
37637 @var{root} at all if possible), @code{yes} (repair as much as possible),
37638 or @code{preen} to repair problems considered safe to repair automatically.
37640 @code{preen} is the default if this option is not present or if @var{level}
37641 is not one of the above.
37643 @item gnu.system=@var{system}
37644 Have @file{/run/booted-system} and @file{/run/current-system} point to
37647 @item modprobe.blacklist=@var{modules}@dots{}
37648 @cindex module, black-listing
37649 @cindex black list, of kernel modules
37650 Instruct the initial RAM disk as well as the @command{modprobe} command
37651 (from the kmod package) to refuse to load @var{modules}. @var{modules}
37652 must be a comma-separated list of module names---e.g.,
37653 @code{usbkbd,9pnet}.
37656 Start a read-eval-print loop (REPL) from the initial RAM disk before it
37657 tries to load kernel modules and to mount the root file system. Our
37658 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
37659 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
37660 Manual}, for more information on Guile's REPL.
37664 Now that you know all the features that initial RAM disks produced by
37665 @code{base-initrd} and @code{raw-initrd} provide,
37666 here is how to use it and customize it further.
37669 @cindex initial RAM disk
37670 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
37671 [#:linux-modules '()] [#:mapped-devices '()] @
37672 [#:keyboard-layout #f] @
37673 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
37674 Return a derivation that builds a raw initrd. @var{file-systems} is
37675 a list of file systems to be mounted by the initrd, possibly in addition to
37676 the root file system specified on the kernel command line via @option{root}.
37677 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
37678 @var{mapped-devices} is a list of device mappings to realize before
37679 @var{file-systems} are mounted (@pxref{Mapped Devices}).
37680 @var{helper-packages} is a list of packages to be copied in the initrd.
37682 include @code{e2fsck/static} or other packages needed by the initrd to check
37683 the root file system.
37685 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
37686 the desired console keyboard layout. This is done before @var{mapped-devices}
37687 are set up and before @var{file-systems} are mounted such that, should the
37688 user need to enter a passphrase or use the REPL, this happens using the
37689 intended keyboard layout.
37691 When @var{qemu-networking?} is true, set up networking with the standard QEMU
37692 parameters. When @var{virtio?} is true, load additional modules so that the
37693 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
37695 When @var{volatile-root?} is true, the root file system is writable but any changes
37699 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
37700 [#:mapped-devices '()] [#:keyboard-layout #f] @
37701 [#:qemu-networking? #f] [#:volatile-root? #f] @
37702 [#:linux-modules '()]
37703 Return as a file-like object a generic initrd, with kernel
37704 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
37705 mounted by the initrd, possibly in addition to the root file system specified
37706 on the kernel command line via @option{root}. @var{mapped-devices} is a list of device
37707 mappings to realize before @var{file-systems} are mounted.
37709 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
37710 the desired console keyboard layout. This is done before @var{mapped-devices}
37711 are set up and before @var{file-systems} are mounted such that, should the
37712 user need to enter a passphrase or use the REPL, this happens using the
37713 intended keyboard layout.
37715 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
37717 The initrd is automatically populated with all the kernel modules necessary
37718 for @var{file-systems} and for the given options. Additional kernel
37719 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
37720 loaded at boot time in the order in which they appear.
37723 Needless to say, the initrds we produce and use embed a
37724 statically-linked Guile, and the initialization program is a Guile
37725 program. That gives a lot of flexibility. The
37726 @code{expression->initrd} procedure builds such an initrd, given the
37727 program to run in that initrd.
37729 @deffn {Scheme Procedure} expression->initrd @var{exp} @
37730 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
37731 Return as a file-like object a Linux initrd (a gzipped cpio archive)
37732 containing @var{guile} and that evaluates @var{exp}, a G-expression,
37733 upon booting. All the derivations referenced by @var{exp} are
37734 automatically copied to the initrd.
37737 @node Bootloader Configuration
37738 @section Bootloader Configuration
37741 @cindex boot loader
37743 The operating system supports multiple bootloaders. The bootloader is
37744 configured using @code{bootloader-configuration} declaration. All the
37745 fields of this structure are bootloader agnostic except for one field,
37746 @code{bootloader} that indicates the bootloader to be configured and
37749 Some of the bootloaders do not honor every field of
37750 @code{bootloader-configuration}. For instance, the extlinux
37751 bootloader does not support themes and thus ignores the @code{theme}
37754 @deftp {Data Type} bootloader-configuration
37755 The type of a bootloader configuration declaration.
37759 @item @code{bootloader}
37760 @cindex EFI, bootloader
37761 @cindex UEFI, bootloader
37762 @cindex BIOS, bootloader
37763 The bootloader to use, as a @code{bootloader} object. For now
37764 @code{grub-bootloader}, @code{grub-efi-bootloader},
37765 @code{grub-efi-netboot-bootloader}, @code{grub-efi-removable-bootloader},
37766 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
37768 @cindex ARM, bootloaders
37769 @cindex AArch64, bootloaders
37770 Available bootloaders are described in @code{(gnu bootloader @dots{})}
37771 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
37772 of bootloaders for a wide range of ARM and AArch64 systems, using the
37773 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
37775 @vindex grub-efi-bootloader
37776 @code{grub-efi-bootloader} allows to boot on modern systems using the
37777 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
37778 use if the installation image contains a @file{/sys/firmware/efi} directory
37779 when you boot it on your system.
37781 @vindex grub-bootloader
37782 @code{grub-bootloader} allows you to boot in particular Intel-based machines
37783 in ``legacy'' BIOS mode.
37785 @vindex grub-efi-netboot-bootloader
37786 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
37787 through TFTP@. In combination with an NFS root file system this allows you to
37788 build a diskless Guix system.
37790 The installation of the @code{grub-efi-netboot-bootloader} generates the
37791 content of the TFTP root directory at @code{targets} (@pxref{Bootloader
37792 Configuration, @code{targets}}), to be served by a TFTP server. You may
37793 want to mount your TFTP server directories onto the @code{targets} to
37794 move the required files to the TFTP server automatically.
37796 If you plan to use an NFS root file system as well (actually if you mount the
37797 store from an NFS share), then the TFTP server needs to serve the file
37798 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
37799 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
37800 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
37801 files from the store will be accessed by GRUB through TFTP with their normal
37802 store path, for example as
37803 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
37805 Two symlinks are created to make this possible. For each target in the
37806 @code{targets} field, the first symlink is
37807 @samp{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
37808 @file{../../../boot/grub/grub.cfg}, where @samp{target} may be
37809 @file{/boot}. In this case the link is not leaving the served TFTP root
37810 directory, but otherwise it does. The second link is
37811 @samp{target}@file{/gnu/store} and points to @file{../gnu/store}. This
37812 link is leaving the served TFTP root directory.
37814 The assumption behind all this is that you have an NFS server exporting
37815 the root file system for your Guix system, and additionally a TFTP
37816 server exporting your @code{targets} directories—usually a single
37817 @file{/boot}—from that same root file system for your Guix system. In
37818 this constellation the symlinks will work.
37820 For other constellations you will have to program your own bootloader
37821 installer, which then takes care to make necessary files from the store
37822 accessible through TFTP, for example by copying them into the TFTP root
37823 directory to your @code{targets}.
37825 It is important to note that symlinks pointing outside the TFTP root directory
37826 may need to be allowed in the configuration of your TFTP server. Further the
37827 store link exposes the whole store through TFTP@. Both points need to be
37828 considered carefully for security aspects.
37830 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
37831 NFS servers, you also need a properly configured DHCP server to make the booting
37832 over netboot possible. For all this we can currently only recommend you to look
37833 for instructions about @acronym{PXE, Preboot eXecution Environment}.
37835 @vindex grub-efi-removable-bootloader
37836 @code{grub-efi-removable-bootloader} allows you to boot your system from
37837 removable media by writing the GRUB file to the UEFI-specification location of
37838 @file{/EFI/BOOT/BOOTX64.efi} of the boot directory, usually @file{/boot/efi}.
37839 This is also useful for some UEFI firmwares that ``forget'' their configuration
37840 from their non-volatile storage. Like @code{grub-efi-bootloader}, this can only
37841 be used if the @file{/sys/firmware/efi} directory is available.
37844 This @emph{will} overwrite the GRUB file from any other operating systems that
37845 also place their GRUB file in the UEFI-specification location; making them
37849 @item @code{targets}
37850 This is a list of strings denoting the targets onto which to install the
37853 The interpretation of targets depends on the bootloader in question.
37854 For @code{grub-bootloader}, for example, they should be device names
37855 understood by the bootloader @command{installer} command, such as
37856 @code{/dev/sda} or @code{(hd0)} (@pxref{Invoking grub-install,,, grub,
37857 GNU GRUB Manual}). For @code{grub-efi-bootloader} and
37858 @code{grub-efi-removable-bootloader} they should be mount
37859 points of the EFI file system, usually @file{/boot/efi}. For
37860 @code{grub-efi-netboot-bootloader}, @code{targets} should be the mount
37861 points corresponding to TFTP root directories served by your TFTP
37864 @item @code{menu-entries} (default: @code{()})
37865 A possibly empty list of @code{menu-entry} objects (see below), denoting
37866 entries to appear in the bootloader menu, in addition to the current
37867 system entry and the entry pointing to previous system generations.
37869 @item @code{default-entry} (default: @code{0})
37870 The index of the default boot menu entry. Index 0 is for the entry of the
37873 @item @code{timeout} (default: @code{5})
37874 The number of seconds to wait for keyboard input before booting. Set to
37875 0 to boot immediately, and to -1 to wait indefinitely.
37877 @cindex keyboard layout, for the bootloader
37878 @item @code{keyboard-layout} (default: @code{#f})
37879 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
37880 layout, usually US@tie{}English (``qwerty'').
37882 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
37886 This option is currently ignored by bootloaders other than @code{grub} and
37890 @item @code{theme} (default: @var{#f})
37891 The bootloader theme object describing the theme to use. If no theme
37892 is provided, some bootloaders might use a default theme, that's true
37895 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
37896 The output terminals used for the bootloader boot menu, as a list of
37897 symbols. GRUB accepts the values: @code{console}, @code{serial},
37898 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
37899 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
37900 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
37901 configuration,,, grub,GNU GRUB manual}).
37903 @item @code{terminal-inputs} (default: @code{'()})
37904 The input terminals used for the bootloader boot menu, as a list of
37905 symbols. For GRUB, the default is the native platform terminal as
37906 determined at run-time. GRUB accepts the values: @code{console},
37907 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
37908 @code{usb_keyboard}. This field corresponds to the GRUB variable
37909 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
37912 @item @code{serial-unit} (default: @code{#f})
37913 The serial unit used by the bootloader, as an integer from 0 to 3.
37914 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
37915 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
37917 @item @code{serial-speed} (default: @code{#f})
37918 The speed of the serial interface, as an integer. For GRUB, the
37919 default value is chosen at run-time; currently GRUB chooses
37920 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
37922 @item @code{device-tree-support?} (default: @code{#t})
37923 Whether to support Linux @uref{https://en.wikipedia.org/wiki/Devicetree,
37924 device tree} files loading.
37926 This option in enabled by default. In some cases involving the
37927 @code{u-boot} bootloader, where the device tree has already been loaded
37928 in RAM, it can be handy to disable the option by setting it to
37936 Should you want to list additional boot menu entries @i{via} the
37937 @code{menu-entries} field above, you will need to create them with the
37938 @code{menu-entry} form. For example, imagine you want to be able to
37939 boot another distro (hard to imagine!), you can define a menu entry
37944 (label "The Other Distro")
37945 (linux "/boot/old/vmlinux-2.6.32")
37946 (linux-arguments '("root=/dev/sda2"))
37947 (initrd "/boot/old/initrd"))
37952 @deftp {Data Type} menu-entry
37953 The type of an entry in the bootloader menu.
37958 The label to show in the menu---e.g., @code{"GNU"}.
37960 @item @code{linux} (default: @code{#f})
37961 The Linux kernel image to boot, for example:
37964 (file-append linux-libre "/bzImage")
37967 For GRUB, it is also possible to specify a device explicitly in the
37968 file path using GRUB's device naming convention (@pxref{Naming
37969 convention,,, grub, GNU GRUB manual}), for example:
37972 "(hd0,msdos1)/boot/vmlinuz"
37975 If the device is specified explicitly as above, then the @code{device}
37976 field is ignored entirely.
37978 @item @code{linux-arguments} (default: @code{()})
37979 The list of extra Linux kernel command-line arguments---e.g.,
37980 @code{("console=ttyS0")}.
37982 @item @code{initrd} (default: @code{#f})
37983 A G-Expression or string denoting the file name of the initial RAM disk
37984 to use (@pxref{G-Expressions}).
37986 @item @code{device} (default: @code{#f})
37987 The device where the kernel and initrd are to be found---i.e., for GRUB,
37988 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
37990 This may be a file system label (a string), a file system UUID (a
37991 bytevector, @pxref{File Systems}), or @code{#f}, in which case
37992 the bootloader will search the device containing the file specified by
37993 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
37994 must @emph{not} be an OS device name such as @file{/dev/sda1}.
37996 @item @code{multiboot-kernel} (default: @code{#f})
37997 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
37998 manual}). When this field is set, a Multiboot menu-entry is generated.
38002 (file-append mach "/boot/gnumach")
38005 @item @code{multiboot-arguments} (default: @code{()})
38006 The list of extra command-line arguments for the multiboot-kernel.
38008 @item @code{multiboot-modules} (default: @code{()})
38009 The list of commands for loading Multiboot modules. For example:
38012 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
38014 (list (file-append libc "/lib/ld.so.1") "exec"
38018 @item @code{chain-loader} (default: @code{#f})
38019 A string that can be accepted by @code{grub}'s @code{chainloader}
38020 directive. This has no effect if either @code{linux} or
38021 @code{multiboot-kernel} fields are specified. The following is an
38022 example of chainloading a different GNU/Linux system.
38026 (bootloader-configuration
38031 (label "GNU/Linux")
38032 (device (uuid "1C31-A17C" 'fat))
38033 (chain-loader "/EFI/GNULinux/grubx64.efi"))))))
38042 @c FIXME: Write documentation once it's stable.
38043 For now only GRUB has theme support. GRUB themes are created using
38044 the @code{grub-theme} form, which is not fully documented yet.
38046 @deftp {Data Type} grub-theme
38047 Data type representing the configuration of the GRUB theme.
38050 @item @code{gfxmode} (default: @code{'("auto")})
38051 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
38052 @pxref{gfxmode,,, grub, GNU GRUB manual}).
38056 @deffn {Scheme Procedure} grub-theme
38057 Return the default GRUB theme used by the operating system if no
38058 @code{theme} field is specified in @code{bootloader-configuration}
38061 It comes with a fancy background image displaying the GNU and Guix
38065 For example, to override the default resolution, you may use something
38070 (bootloader-configuration
38073 (inherit (grub-theme))
38074 (gfxmode '("1024x786x32" "auto"))))))
38077 @node Invoking guix system
38078 @section Invoking @command{guix system}
38080 @cindex @command{guix system}
38081 Once you have written an operating system declaration as seen in the
38082 previous section, it can be @dfn{instantiated} using the @command{guix
38083 system} command. The synopsis is:
38086 guix system @var{options}@dots{} @var{action} @var{file}
38089 @var{file} must be the name of a file containing an
38090 @code{operating-system} declaration. @var{action} specifies how the
38091 operating system is instantiated. Currently the following values are
38096 Display available service type definitions that match the given regular
38097 expressions, sorted by relevance:
38103 $ guix system search console
38104 name: console-fonts
38105 location: gnu/services/base.scm:806:2
38106 extends: shepherd-root
38107 description: Install the given fonts on the specified ttys (fonts are per
38108 + virtual console on GNU/Linux). The value of this service is a list of
38109 + tty/font pairs. The font can be the name of a font provided by the `kbd'
38110 + package or any valid argument to `setfont', as in this example:
38112 + '(("tty1" . "LatGrkCyr-8x16")
38113 + ("tty2" . (file-append
38115 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
38116 + ("tty3" . (file-append
38118 + "/share/consolefonts/ter-132n"))) ; for HDPI
38122 location: gnu/services/base.scm:1190:2
38123 extends: shepherd-root
38124 description: Provide console login using the `mingetty' program.
38128 location: gnu/services/base.scm:860:2
38130 description: Provide a console log-in service as specified by its
38131 + configuration value, a `login-configuration' object.
38137 As for @command{guix package --search}, the result is written in
38138 @code{recutils} format, which makes it easy to filter the output
38139 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
38141 @cindex service type definition, editing
38142 @cindex editing, service type definition
38144 Edit or view the definition of the given service types.
38146 For example, the command below opens your editor, as specified by the
38147 @env{EDITOR} environment variable, on the definition of the
38148 @code{openssh} service type:
38151 guix system edit openssh
38155 Build the operating system described in @var{file}, activate it, and
38156 switch to it@footnote{This action (and the related actions
38157 @code{switch-generation} and @code{roll-back}) are usable only on
38158 systems already running Guix System.}.
38161 @c The paragraph below refers to the problem discussed at
38162 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
38163 It is highly recommended to run @command{guix pull} once before you run
38164 @command{guix system reconfigure} for the first time (@pxref{Invoking
38165 guix pull}). Failing to do that you would see an older version of Guix
38166 once @command{reconfigure} has completed.
38169 This effects all the configuration specified in @var{file}: user
38170 accounts, system services, global package list, setuid programs, etc.
38171 The command starts system services specified in @var{file} that are not
38172 currently running; if a service is currently running this command will
38173 arrange for it to be upgraded the next time it is stopped (e.g.@: by
38174 @code{herd stop X} or @code{herd restart X}).
38176 This command creates a new generation whose number is one greater than
38177 the current generation (as reported by @command{guix system
38178 list-generations}). If that generation already exists, it will be
38179 overwritten. This behavior mirrors that of @command{guix package}
38180 (@pxref{Invoking guix package}).
38182 It also adds a bootloader menu entry for the new OS configuration,
38183 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
38184 entries for older configurations to a submenu, allowing you to choose
38185 an older system generation at boot time should you need it.
38187 @cindex provenance tracking, of the operating system
38188 Upon completion, the new system is deployed under
38189 @file{/run/current-system}. This directory contains @dfn{provenance
38190 meta-data}: the list of channels in use (@pxref{Channels}) and
38191 @var{file} itself, when available. You can view it by running:
38194 guix system describe
38197 This information is useful should you later want to inspect how this
38198 particular generation was built. In fact, assuming @var{file} is
38199 self-contained, you can later rebuild generation @var{n} of your
38200 operating system with:
38203 guix time-machine \
38204 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
38205 system reconfigure \
38206 /var/guix/profiles/system-@var{n}-link/configuration.scm
38209 You can think of it as some sort of built-in version control! Your
38210 system is not just a binary artifact: @emph{it carries its own source}.
38211 @xref{Service Reference, @code{provenance-service-type}}, for more
38212 information on provenance tracking.
38214 By default, @command{reconfigure} @emph{prevents you from downgrading
38215 your system}, which could (re)introduce security vulnerabilities and
38216 also cause problems with ``stateful'' services such as database
38217 management systems. You can override that behavior by passing
38218 @option{--allow-downgrades}.
38220 @item switch-generation
38221 @cindex generations
38222 Switch to an existing system generation. This action atomically
38223 switches the system profile to the specified system generation. It
38224 also rearranges the system's existing bootloader menu entries. It
38225 makes the menu entry for the specified system generation the default,
38226 and it moves the entries for the other generations to a submenu, if
38227 supported by the bootloader being used. The next time the system
38228 boots, it will use the specified system generation.
38230 The bootloader itself is not being reinstalled when using this
38231 command. Thus, the installed bootloader is used with an updated
38232 configuration file.
38234 The target generation can be specified explicitly by its generation
38235 number. For example, the following invocation would switch to system
38239 guix system switch-generation 7
38242 The target generation can also be specified relative to the current
38243 generation with the form @code{+N} or @code{-N}, where @code{+3} means
38244 ``3 generations ahead of the current generation,'' and @code{-1} means
38245 ``1 generation prior to the current generation.'' When specifying a
38246 negative value such as @code{-1}, you must precede it with @code{--} to
38247 prevent it from being parsed as an option. For example:
38250 guix system switch-generation -- -1
38253 Currently, the effect of invoking this action is @emph{only} to switch
38254 the system profile to an existing generation and rearrange the
38255 bootloader menu entries. To actually start using the target system
38256 generation, you must reboot after running this action. In the future,
38257 it will be updated to do the same things as @command{reconfigure},
38258 like activating and deactivating services.
38260 This action will fail if the specified generation does not exist.
38263 @cindex rolling back
38264 Switch to the preceding system generation. The next time the system
38265 boots, it will use the preceding system generation. This is the inverse
38266 of @command{reconfigure}, and it is exactly the same as invoking
38267 @command{switch-generation} with an argument of @code{-1}.
38269 Currently, as with @command{switch-generation}, you must reboot after
38270 running this action to actually start using the preceding system
38273 @item delete-generations
38274 @cindex deleting system generations
38275 @cindex saving space
38276 Delete system generations, making them candidates for garbage collection
38277 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
38280 This works in the same way as @samp{guix package --delete-generations}
38281 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
38282 arguments, all system generations but the current one are deleted:
38285 guix system delete-generations
38288 You can also select the generations you want to delete. The example below
38289 deletes all the system generations that are more than two months old:
38292 guix system delete-generations 2m
38295 Running this command automatically reinstalls the bootloader with an updated
38296 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
38297 longer lists the generations that have been deleted.
38300 Build the derivation of the operating system, which includes all the
38301 configuration files and programs needed to boot and run the system.
38302 This action does not actually install anything.
38305 Populate the given directory with all the files necessary to run the
38306 operating system specified in @var{file}. This is useful for first-time
38307 installations of Guix System. For instance:
38310 guix system init my-os-config.scm /mnt
38313 copies to @file{/mnt} all the store items required by the configuration
38314 specified in @file{my-os-config.scm}. This includes configuration
38315 files, packages, and so on. It also creates other essential files
38316 needed for the system to operate correctly---e.g., the @file{/etc},
38317 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
38319 This command also installs bootloader on the targets specified in
38320 @file{my-os-config}, unless the @option{--no-bootloader} option was
38324 @cindex virtual machine
38326 @anchor{guix system vm}
38327 Build a virtual machine (VM) that contains the operating system declared
38328 in @var{file}, and return a script to run that VM.
38331 The @code{vm} action and others below
38332 can use KVM support in the Linux-libre kernel. Specifically, if the
38333 machine has hardware virtualization support, the corresponding
38334 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
38335 must exist and be readable and writable by the user and by the
38336 build users of the daemon (@pxref{Build Environment Setup}).
38339 Arguments given to the script are passed to QEMU as in the example
38340 below, which enables networking and requests 1@tie{}GiB of RAM for the
38344 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -nic user,model=virtio-net-pci
38347 It's possible to combine the two steps into one:
38350 $ $(guix system vm my-config.scm) -m 1024 -smp 2 -nic user,model=virtio-net-pci
38353 The VM shares its store with the host system.
38355 By default, the root file system of the VM is mounted volatile; the
38356 @option{--persistent} option can be provided to make it persistent
38357 instead. In that case, the VM disk-image file will be copied from the
38358 store to the @env{TMPDIR} directory to make it writable.
38360 Additional file systems can be shared between the host and the VM using
38361 the @option{--share} and @option{--expose} command-line options: the former
38362 specifies a directory to be shared with write access, while the latter
38363 provides read-only access to the shared directory.
38365 The example below creates a VM in which the user's home directory is
38366 accessible read-only, and where the @file{/exchange} directory is a
38367 read-write mapping of @file{$HOME/tmp} on the host:
38370 guix system vm my-config.scm \
38371 --expose=$HOME --share=$HOME/tmp=/exchange
38374 On GNU/Linux, the default is to boot directly to the kernel; this has
38375 the advantage of requiring only a very tiny root disk image since the
38376 store of the host can then be mounted.
38378 The @option{--full-boot} option forces a complete boot sequence, starting
38379 with the bootloader. This requires more disk space since a root image
38380 containing at least the kernel, initrd, and bootloader data files must
38383 The @option{--image-size} option can be used to specify the size of the
38386 The @option{--no-graphic} option will instruct @command{guix system} to
38387 spawn a headless VM that will use the invoking tty for IO. Among other
38388 things, this enables copy-pasting, and scrollback. Use the @kbd{ctrl-a}
38389 prefix to issue QEMU commands; e.g. @kbd{ctrl-a h} prints a help,
38390 @kbd{ctrl-a x} quits the VM, and @kbd{ctrl-a c} switches between the
38391 QEMU monitor and the VM.
38393 @cindex System images, creation in various formats
38394 @cindex Creating system images in various formats
38396 @cindex image, creating disk images
38397 The @code{image} command can produce various image types. The image
38398 type can be selected using the @option{--image-type} option. It
38399 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
38400 @option{--label} option can be used to specify a volume ID with
38401 @code{image}. By default, the root file system of a disk image is
38402 mounted non-volatile; the @option{--volatile} option can be provided to
38403 make it volatile instead. When using @code{image}, the bootloader
38404 installed on the generated image is taken from the provided
38405 @code{operating-system} definition. The following example demonstrates
38406 how to generate an image that uses the @code{grub-efi-bootloader}
38407 bootloader and boot it with QEMU:
38410 image=$(guix system image --image-type=qcow2 \
38411 gnu/system/examples/lightweight-desktop.tmpl)
38412 cp $image /tmp/my-image.qcow2
38413 chmod +w /tmp/my-image.qcow2
38414 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
38415 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
38418 When using the @code{efi-raw} image type, a raw disk image is produced;
38419 it can be copied as is to a USB stick, for instance. Assuming
38420 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
38421 the image to it using the following command:
38424 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
38427 The @code{--list-image-types} command lists all the available image
38430 @cindex creating virtual machine images
38431 When using the @code{qcow2} image type, the returned image is in qcow2
38432 format, which the QEMU emulator can efficiently use. @xref{Running Guix
38433 in a VM}, for more information on how to run the image in a virtual
38434 machine. The @code{grub-bootloader} bootloader is always used
38435 independently of what is declared in the @code{operating-system} file
38436 passed as argument. This is to make it easier to work with QEMU, which
38437 uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
38438 in the Master Boot Record (MBR).
38440 @cindex docker-image, creating docker images
38441 When using the @code{docker} image type, a Docker image is produced.
38442 Guix builds the image from scratch, not from a pre-existing Docker base
38443 image. As a result, it contains @emph{exactly} what you define in the
38444 operating system configuration file. You can then load the image and
38445 launch a Docker container using commands like the following:
38448 image_id="$(docker load < guix-system-docker-image.tar.gz)"
38449 container_id="$(docker create $image_id)"
38450 docker start $container_id
38453 This command starts a new Docker container from the specified image. It
38454 will boot the Guix system in the usual manner, which means it will
38455 start any services you have defined in the operating system
38456 configuration. You can get an interactive shell running in the container
38457 using @command{docker exec}:
38460 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
38463 Depending on what you run in the Docker container, it
38464 may be necessary to give the container additional permissions. For
38465 example, if you intend to build software using Guix inside of the Docker
38466 container, you may need to pass the @option{--privileged} option to
38467 @code{docker create}.
38469 Last, the @option{--network} option applies to @command{guix system
38470 docker-image}: it produces an image where network is supposedly shared
38471 with the host, and thus without services like nscd or NetworkManager.
38474 Return a script to run the operating system declared in @var{file}
38475 within a container. Containers are a set of lightweight isolation
38476 mechanisms provided by the kernel Linux-libre. Containers are
38477 substantially less resource-demanding than full virtual machines since
38478 the kernel, shared objects, and other resources can be shared with the
38479 host system; this also means they provide thinner isolation.
38481 Currently, the script must be run as root in order to support more than
38482 a single user and group. The container shares its store with the host
38485 As with the @code{vm} action (@pxref{guix system vm}), additional file
38486 systems to be shared between the host and container can be specified
38487 using the @option{--share} and @option{--expose} options:
38490 guix system container my-config.scm \
38491 --expose=$HOME --share=$HOME/tmp=/exchange
38494 The @option{--share} and @option{--expose} options can also be passed to
38495 the generated script to bind-mount additional directories into the
38499 This option requires Linux-libre 3.19 or newer.
38504 @var{options} can contain any of the common build options (@pxref{Common
38505 Build Options}). In addition, @var{options} can contain one of the
38509 @item --expression=@var{expr}
38510 @itemx -e @var{expr}
38511 Consider the operating-system @var{expr} evaluates to.
38512 This is an alternative to specifying a file which evaluates to an
38514 This is used to generate the Guix system installer @pxref{Building the
38515 Installation Image}).
38517 @item --system=@var{system}
38518 @itemx -s @var{system}
38519 Attempt to build for @var{system} instead of the host system type.
38520 This works as per @command{guix build} (@pxref{Invoking guix build}).
38522 @item --target=@var{triplet}
38523 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
38524 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
38525 configuration triplets,, autoconf, Autoconf}).
38529 Return the derivation file name of the given operating system without
38532 @cindex provenance tracking, of the operating system
38533 @item --save-provenance
38534 As discussed above, @command{guix system init} and @command{guix system
38535 reconfigure} always save provenance information @i{via} a dedicated
38536 service (@pxref{Service Reference, @code{provenance-service-type}}).
38537 However, other commands don't do that by default. If you wish to, say,
38538 create a virtual machine image that contains provenance information, you
38542 guix system image -t qcow2 --save-provenance config.scm
38545 That way, the resulting image will effectively ``embed its own source''
38546 in the form of meta-data in @file{/run/current-system}. With that
38547 information, one can rebuild the image to make sure it really contains
38548 what it pretends to contain; or they could use that to derive a variant
38551 @item --image-type=@var{type}
38552 @itemx -t @var{type}
38553 For the @code{image} action, create an image with given @var{type}.
38555 When this option is omitted, @command{guix system} uses the
38556 @code{efi-raw} image type.
38558 @cindex ISO-9660 format
38559 @cindex CD image format
38560 @cindex DVD image format
38561 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
38562 for burning on CDs and DVDs.
38564 @item --image-size=@var{size}
38565 For the @code{image} action, create an image of the given @var{size}.
38566 @var{size} may be a number of bytes, or it may include a unit as a
38567 suffix (@pxref{Block size, size specifications,, coreutils, GNU
38570 When this option is omitted, @command{guix system} computes an estimate
38571 of the image size as a function of the size of the system declared in
38576 For the @code{container} action, allow containers to access the host network,
38577 that is, do not create a network namespace.
38579 @item --root=@var{file}
38580 @itemx -r @var{file}
38581 Make @var{file} a symlink to the result, and register it as a garbage
38584 @item --skip-checks
38585 Skip pre-installation safety checks.
38587 By default, @command{guix system init} and @command{guix system
38588 reconfigure} perform safety checks: they make sure the file systems that
38589 appear in the @code{operating-system} declaration actually exist
38590 (@pxref{File Systems}), and that any Linux kernel modules that may be
38591 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
38592 RAM Disk}). Passing this option skips these tests altogether.
38594 @item --allow-downgrades
38595 Instruct @command{guix system reconfigure} to allow system downgrades.
38597 By default, @command{reconfigure} prevents you from downgrading your
38598 system. It achieves that by comparing the provenance info of your
38599 system (shown by @command{guix system describe}) with that of your
38600 @command{guix} command (shown by @command{guix describe}). If the
38601 commits for @command{guix} are not descendants of those used for your
38602 system, @command{guix system reconfigure} errors out. Passing
38603 @option{--allow-downgrades} allows you to bypass these checks.
38606 Make sure you understand its security implications before using
38607 @option{--allow-downgrades}.
38611 @cindex on-error strategy
38612 @cindex error strategy
38613 @item --on-error=@var{strategy}
38614 Apply @var{strategy} when an error occurs when reading @var{file}.
38615 @var{strategy} may be one of the following:
38618 @item nothing-special
38619 Report the error concisely and exit. This is the default strategy.
38622 Likewise, but also display a backtrace.
38625 Report the error and enter Guile's debugger. From there, you can run
38626 commands such as @code{,bt} to get a backtrace, @code{,locals} to
38627 display local variable values, and more generally inspect the state of the
38628 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
38629 a list of available debugging commands.
38633 Once you have built, configured, re-configured, and re-re-configured
38634 your Guix installation, you may find it useful to list the operating
38635 system generations available on disk---and that you can choose from the
38636 bootloader boot menu:
38641 Describe the running system generation: its file name, the kernel and
38642 bootloader used, etc., as well as provenance information when available.
38644 The @code{--list-installed} flag is available, with the same
38645 syntax that is used in @command{guix package --list-installed}
38646 (@pxref{Invoking guix package}). When the flag is used,
38647 the description will include a list of packages that are currently
38648 installed in the system profile, with optional filtering based on a
38649 regular expression.
38652 The @emph{running} system generation---referred to by
38653 @file{/run/current-system}---is not necessarily the @emph{current}
38654 system generation---referred to by @file{/var/guix/profiles/system}: it
38655 differs when, for instance, you chose from the bootloader menu to boot
38656 an older generation.
38658 It can also differ from the @emph{booted} system generation---referred
38659 to by @file{/run/booted-system}---for instance because you reconfigured
38660 the system in the meantime.
38663 @item list-generations
38664 List a summary of each generation of the operating system available on
38665 disk, in a human-readable way. This is similar to the
38666 @option{--list-generations} option of @command{guix package}
38667 (@pxref{Invoking guix package}).
38669 Optionally, one can specify a pattern, with the same syntax that is used
38670 in @command{guix package --list-generations}, to restrict the list of
38671 generations displayed. For instance, the following command displays
38672 generations that are up to 10 days old:
38675 $ guix system list-generations 10d
38678 The @code{--list-installed} flag may also be specified, with the same
38679 syntax that is used in @command{guix package --list-installed}. This
38680 may be helpful if trying to determine when a package was added to the
38685 The @command{guix system} command has even more to offer! The following
38686 sub-commands allow you to visualize how your system services relate to
38689 @anchor{system-extension-graph}
38692 @item extension-graph
38693 Emit to standard output the @dfn{service
38694 extension graph} of the operating system defined in @var{file}
38695 (@pxref{Service Composition}, for more information on service
38696 extensions). By default the output is in Dot/Graphviz format, but you
38697 can choose a different format with @option{--graph-backend}, as with
38698 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
38703 $ guix system extension-graph @var{file} | xdot -
38706 shows the extension relations among services.
38709 The @command{dot} program is provided by the @code{graphviz} package.
38712 @anchor{system-shepherd-graph}
38713 @item shepherd-graph
38714 Emit to standard output the @dfn{dependency
38715 graph} of shepherd services of the operating system defined in
38716 @var{file}. @xref{Shepherd Services}, for more information and for an
38719 Again, the default output format is Dot/Graphviz, but you can pass
38720 @option{--graph-backend} to select a different one.
38724 @node Invoking guix deploy
38725 @section Invoking @command{guix deploy}
38727 @cindex @command{guix deploy}
38728 We've already seen @code{operating-system} declarations used to manage a
38729 machine's configuration locally. Suppose you need to configure multiple
38730 machines, though---perhaps you're managing a service on the web that's
38731 comprised of several servers. @command{guix deploy} enables you to use those
38732 same @code{operating-system} declarations to manage multiple remote hosts at
38733 once as a logical ``deployment''.
38736 The functionality described in this section is still under development
38737 and is subject to change. Get in touch with us on
38738 @email{guix-devel@@gnu.org}!
38742 guix deploy @var{file}
38745 Such an invocation will deploy the machines that the code within @var{file}
38746 evaluates to. As an example, @var{file} might contain a definition like this:
38749 ;; This is a Guix deployment of a "bare bones" setup, with
38750 ;; no X11 display server, to a machine with an SSH daemon
38751 ;; listening on localhost:2222. A configuration such as this
38752 ;; may be appropriate for virtual machine with ports
38753 ;; forwarded to the host's loopback interface.
38755 (use-service-modules networking ssh)
38756 (use-package-modules bootloaders)
38760 (host-name "gnu-deployed")
38761 (timezone "Etc/UTC")
38762 (bootloader (bootloader-configuration
38763 (bootloader grub-bootloader)
38764 (targets '("/dev/vda"))
38765 (terminal-outputs '(console))))
38766 (file-systems (cons (file-system
38768 (device "/dev/vda1")
38770 %base-file-systems))
38772 (append (list (service dhcp-client-service-type)
38773 (service openssh-service-type
38774 (openssh-configuration
38775 (permit-root-login #t)
38776 (allow-empty-passwords? #t))))
38780 (operating-system %system)
38781 (environment managed-host-environment-type)
38782 (configuration (machine-ssh-configuration
38783 (host-name "localhost")
38784 (system "x86_64-linux")
38786 (identity "./id_rsa")
38790 The file should evaluate to a list of @var{machine} objects. This example,
38791 upon being deployed, will create a new generation on the remote system
38792 realizing the @code{operating-system} declaration @code{%system}.
38793 @code{environment} and @code{configuration} specify how the machine should be
38794 provisioned---that is, how the computing resources should be created and
38795 managed. The above example does not create any resources, as a
38796 @code{'managed-host} is a machine that is already running the Guix system and
38797 available over the network. This is a particularly simple case; a more
38798 complex deployment may involve, for example, starting virtual machines through
38799 a Virtual Private Server (VPS) provider. In such a case, a different
38800 @var{environment} type would be used.
38802 Do note that you first need to generate a key pair on the coordinator machine
38803 to allow the daemon to export signed archives of files from the store
38804 (@pxref{Invoking guix archive}), though this step is automatic on Guix
38808 # guix archive --generate-key
38812 Each target machine must authorize the key of the master machine so that it
38813 accepts store items it receives from the coordinator:
38816 # guix archive --authorize < coordinator-public-key.txt
38819 @code{user}, in this example, specifies the name of the user account to log in
38820 as to perform the deployment. Its default value is @code{root}, but root
38821 login over SSH may be forbidden in some cases. To work around this,
38822 @command{guix deploy} can log in as an unprivileged user and employ
38823 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
38824 currently installed on the remote and can be invoked non-interactively as
38825 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
38826 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
38827 be accomplished with the following operating system configuration snippet:
38831 (gnu system)) ;for %sudoers-specification
38833 (define %user "username")
38838 (plain-file "sudoers"
38839 (string-append (plain-file-content %sudoers-specification)
38840 (format #f "~a ALL = NOPASSWD: ALL~%"
38845 For more information regarding the format of the @file{sudoers} file,
38846 consult @command{man sudoers}.
38848 Once you've deployed a system on a set of machines, you may find it
38849 useful to run a command on all of them. The @option{--execute} or
38850 @option{-x} option lets you do that; the example below runs
38851 @command{uname -a} on all the machines listed in the deployment file:
38854 guix deploy @var{file} -x -- uname -a
38857 One thing you may often need to do after deployment is restart specific
38858 services on all the machines, which you can do like so:
38861 guix deploy @var{file} -x -- herd restart @var{service}
38864 The @command{guix deploy -x} command returns zero if and only if the
38865 command succeeded on all the machines.
38867 @c FIXME/TODO: Separate the API doc from the CLI doc.
38869 Below are the data types you need to know about when writing a
38872 @deftp {Data Type} machine
38873 This is the data type representing a single machine in a heterogeneous Guix
38877 @item @code{operating-system}
38878 The object of the operating system configuration to deploy.
38880 @item @code{environment}
38881 An @code{environment-type} describing how the machine should be provisioned.
38883 @item @code{configuration} (default: @code{#f})
38884 An object describing the configuration for the machine's @code{environment}.
38885 If the @code{environment} has a default configuration, @code{#f} may be used.
38886 If @code{#f} is used for an environment with no default configuration,
38887 however, an error will be thrown.
38891 @deftp {Data Type} machine-ssh-configuration
38892 This is the data type representing the SSH client parameters for a machine
38893 with an @code{environment} of @code{managed-host-environment-type}.
38896 @item @code{host-name}
38897 @item @code{build-locally?} (default: @code{#t})
38898 If false, system derivations will be built on the machine being deployed to.
38899 @item @code{system}
38900 The system type describing the architecture of the machine being deployed
38901 to---e.g., @code{"x86_64-linux"}.
38902 @item @code{authorize?} (default: @code{#t})
38903 If true, the coordinator's signing key will be added to the remote's ACL
38905 @item @code{port} (default: @code{22})
38906 @item @code{user} (default: @code{"root"})
38907 @item @code{identity} (default: @code{#f})
38908 If specified, the path to the SSH private key to use to authenticate with the
38911 @item @code{host-key} (default: @code{#f})
38912 This should be the SSH host key of the machine, which looks like this:
38915 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
38918 When @code{host-key} is @code{#f}, the server is authenticated against
38919 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
38922 @item @code{allow-downgrades?} (default: @code{#f})
38923 Whether to allow potential downgrades.
38925 Like @command{guix system reconfigure}, @command{guix deploy} compares
38926 the channel commits currently deployed on the remote host (as returned
38927 by @command{guix system describe}) to those currently in use (as
38928 returned by @command{guix describe}) to determine whether commits
38929 currently in use are descendants of those deployed. When this is not
38930 the case and @code{allow-downgrades?} is false, it raises an error.
38931 This ensures you do not accidentally downgrade remote machines.
38933 @item @code{safety-checks?} (default: @code{#t})
38934 Whether to perform ``safety checks'' before deployment. This includes
38935 verifying that devices and file systems referred to in the operating
38936 system configuration actually exist on the target machine, and making
38937 sure that Linux modules required to access storage devices at boot time
38938 are listed in the @code{initrd-modules} field of the operating system.
38940 These safety checks ensure that you do not inadvertently deploy a system
38941 that would fail to boot. Be careful before turning them off!
38945 @deftp {Data Type} digital-ocean-configuration
38946 This is the data type describing the Droplet that should be created for a
38947 machine with an @code{environment} of @code{digital-ocean-environment-type}.
38950 @item @code{ssh-key}
38951 The path to the SSH private key to use to authenticate with the remote
38952 host. In the future, this field may not exist.
38954 A list of string ``tags'' that uniquely identify the machine. Must be given
38955 such that no two machines in the deployment have the same set of tags.
38956 @item @code{region}
38957 A Digital Ocean region slug, such as @code{"nyc3"}.
38959 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
38960 @item @code{enable-ipv6?}
38961 Whether or not the droplet should be created with IPv6 networking.
38965 @node Running Guix in a VM
38966 @section Running Guix in a Virtual Machine
38968 @cindex virtual machine
38969 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM
38970 image distributed at
38971 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.qcow2}.
38972 This image is a compressed image in QCOW format. You can pass it to an
38973 emulator such as @uref{https://qemu.org/, QEMU} (see below for details).
38975 This image boots the Xfce graphical environment and it contains some
38976 commonly used tools. You can install more software in the image by running
38977 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
38978 also reconfigure the system based on its initial configuration file available
38979 as @file{/run/current-system/configuration.scm} (@pxref{Using the
38980 Configuration System}).
38982 Instead of using this pre-built image, one can also build their own
38983 image using @command{guix system image} (@pxref{Invoking guix system}).
38986 If you built your own image, you must copy it out of the store
38987 (@pxref{The Store}) and give yourself permission to write to the copy
38988 before you can use it. When invoking QEMU, you must choose a system
38989 emulator that is suitable for your hardware platform. Here is a minimal
38990 QEMU invocation that will boot the result of @command{guix system
38991 image -t qcow2} on x86_64 hardware:
38994 $ qemu-system-x86_64 \
38995 -nic user,model=virtio-net-pci \
38996 -enable-kvm -m 2048 \
38997 -device virtio-blk,drive=myhd \
38998 -drive if=none,file=/tmp/qemu-image,id=myhd
39001 Here is what each of these options means:
39004 @item qemu-system-x86_64
39005 This specifies the hardware platform to emulate. This should match the
39008 @item -nic user,model=virtio-net-pci
39009 Enable the unprivileged user-mode network stack. The guest OS can
39010 access the host but not vice versa. This is the simplest way to get the
39011 guest OS online. @code{model} specifies which network device to emulate:
39012 @code{virtio-net-pci} is a special device made for virtualized operating
39013 systems and recommended for most uses. Assuming your hardware platform is
39014 x86_64, you can get a list of available NIC models by running
39015 @command{qemu-system-x86_64 -nic model=help}.
39018 If your system has hardware virtualization extensions, enabling the
39019 virtual machine support (KVM) of the Linux kernel will make things run
39022 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
39024 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
39025 which may be insufficient for some operations.
39027 @item -device virtio-blk,drive=myhd
39028 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
39029 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
39030 better performance than if it were emulating a complete disk drive. See the
39031 QEMU and KVM documentation for more info.
39033 @item -drive if=none,file=/tmp/qemu-image,id=myhd
39034 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
39035 store of the ``myhd'' drive.
39038 The default @command{run-vm.sh} script that is returned by an invocation of
39039 @command{guix system vm} does not add a @command{-nic user} flag by default.
39040 To get network access from within the vm add the @code{(dhcp-client-service)}
39041 to your system definition and start the VM using
39042 @command{$(guix system vm config.scm) -nic user}. An important caveat of using
39043 @command{-nic user} for networking is that @command{ping} will not work, because
39044 it uses the ICMP protocol. You'll have to use a different command to check for
39045 network connectivity, for example @command{guix download}.
39047 @subsection Connecting Through SSH
39051 To enable SSH inside a VM you need to add an SSH server like
39052 @code{openssh-service-type} to your VM (@pxref{Networking Services,
39053 @code{openssh-service-type}}). In addition you need to forward the SSH port,
39054 22 by default, to the host. You can do this with
39057 $(guix system vm config.scm) -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
39060 To connect to the VM you can run
39063 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022 localhost
39066 The @command{-p} tells @command{ssh} the port you want to connect to.
39067 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
39068 every time you modify your @command{config.scm} file and the
39069 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
39070 connection to an unknown host every time you connect.
39073 If you find the above @samp{hostfwd} example not to be working (e.g.,
39074 your SSH client hangs attempting to connect to the mapped port of your
39075 VM), make sure that your Guix System VM has networking support, such as
39076 by using the @code{dhcp-client-service-type} service type.
39079 @subsection Using @command{virt-viewer} with Spice
39081 As an alternative to the default @command{qemu} graphical client you can
39082 use the @command{remote-viewer} from the @command{virt-viewer} package. To
39083 connect pass the @command{-spice port=5930,disable-ticketing} flag to
39084 @command{qemu}. See previous section for further information on how to do this.
39086 Spice also allows you to do some nice stuff like share your clipboard with your
39087 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
39090 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
39091 -chardev spicevmc,name=vdagent,id=vdagent
39092 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,\
39093 name=com.redhat.spice.0
39096 You'll also need to add the @code{(spice-vdagent-service)} to your
39097 system definition (@pxref{Miscellaneous Services, Spice service}).
39099 @node Defining Services
39100 @section Defining Services
39102 The previous sections show the available services and how one can combine
39103 them in an @code{operating-system} declaration. But how do we define
39104 them in the first place? And what is a service anyway?
39107 * Service Composition:: The model for composing services.
39108 * Service Types and Services:: Types and services.
39109 * Service Reference:: API reference.
39110 * Shepherd Services:: A particular type of service.
39111 * Complex Configurations:: Defining bindings for complex configurations.
39114 @node Service Composition
39115 @subsection Service Composition
39119 Here we define a @dfn{service} as, broadly, something that extends the
39120 functionality of the operating system. Often a service is a process---a
39121 @dfn{daemon}---started when the system boots: a secure shell server, a
39122 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
39123 whose execution can be triggered by another daemon---e.g., an FTP server
39124 started by @command{inetd} or a D-Bus service activated by
39125 @command{dbus-daemon}. Occasionally, a service does not map to a
39126 daemon. For instance, the ``account'' service collects user accounts
39127 and makes sure they exist when the system runs; the ``udev'' service
39128 collects device management rules and makes them available to the eudev
39129 daemon; the @file{/etc} service populates the @file{/etc} directory
39132 @cindex service extensions
39133 Guix system services are connected by @dfn{extensions}. For instance, the
39134 secure shell service @emph{extends} the Shepherd---the
39135 initialization system, running as PID@tie{}1---by giving it the command
39136 lines to start and stop the secure shell daemon (@pxref{Networking
39137 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
39138 service by passing it its @file{.service} specification, and extends the
39139 udev service by passing it device management rules (@pxref{Desktop
39140 Services, @code{upower-service}}); the Guix daemon service extends the
39141 Shepherd by passing it the command lines to start and stop the daemon,
39142 and extends the account service by passing it a list of required build
39143 user accounts (@pxref{Base Services}).
39145 All in all, services and their ``extends'' relations form a directed
39146 acyclic graph (DAG). If we represent services as boxes and extensions
39147 as arrows, a typical system might provide something like this:
39149 @image{images/service-graph,,5in,Typical service extension graph.}
39151 @cindex system service
39152 At the bottom, we see the @dfn{system service}, which produces the
39153 directory containing everything to run and boot the system, as returned
39154 by the @command{guix system build} command. @xref{Service Reference},
39155 to learn about the other service types shown here.
39156 @xref{system-extension-graph, the @command{guix system extension-graph}
39157 command}, for information on how to generate this representation for a
39158 particular operating system definition.
39160 @cindex service types
39161 Technically, developers can define @dfn{service types} to express these
39162 relations. There can be any number of services of a given type on the
39163 system---for instance, a system running two instances of the GNU secure
39164 shell server (lsh) has two instances of @code{lsh-service-type}, with
39165 different parameters.
39167 The following section describes the programming interface for service
39168 types and services.
39170 @node Service Types and Services
39171 @subsection Service Types and Services
39173 A @dfn{service type} is a node in the DAG described above. Let us start
39174 with a simple example, the service type for the Guix build daemon
39175 (@pxref{Invoking guix-daemon}):
39178 (define guix-service-type
39182 (list (service-extension shepherd-root-service-type guix-shepherd-service)
39183 (service-extension account-service-type guix-accounts)
39184 (service-extension activation-service-type guix-activation)))
39185 (default-value (guix-configuration))))
39189 It defines three things:
39193 A name, whose sole purpose is to make inspection and debugging easier.
39196 A list of @dfn{service extensions}, where each extension designates the
39197 target service type and a procedure that, given the parameters of the
39198 service, returns a list of objects to extend the service of that type.
39200 Every service type has at least one service extension. The only
39201 exception is the @dfn{boot service type}, which is the ultimate service.
39204 Optionally, a default value for instances of this type.
39207 In this example, @code{guix-service-type} extends three services:
39210 @item shepherd-root-service-type
39211 The @code{guix-shepherd-service} procedure defines how the Shepherd
39212 service is extended. Namely, it returns a @code{<shepherd-service>}
39213 object that defines how @command{guix-daemon} is started and stopped
39214 (@pxref{Shepherd Services}).
39216 @item account-service-type
39217 This extension for this service is computed by @code{guix-accounts},
39218 which returns a list of @code{user-group} and @code{user-account}
39219 objects representing the build user accounts (@pxref{Invoking
39222 @item activation-service-type
39223 Here @code{guix-activation} is a procedure that returns a gexp, which is
39224 a code snippet to run at ``activation time''---e.g., when the service is
39228 A service of this type is instantiated like this:
39231 (service guix-service-type
39232 (guix-configuration
39234 (extra-options '("--gc-keep-derivations"))))
39237 The second argument to the @code{service} form is a value representing
39238 the parameters of this specific service instance.
39239 @xref{guix-configuration-type, @code{guix-configuration}}, for
39240 information about the @code{guix-configuration} data type. When the
39241 value is omitted, the default value specified by
39242 @code{guix-service-type} is used:
39245 (service guix-service-type)
39248 @code{guix-service-type} is quite simple because it extends other
39249 services but is not extensible itself.
39251 @c @subsubsubsection Extensible Service Types
39253 The service type for an @emph{extensible} service looks like this:
39256 (define udev-service-type
39257 (service-type (name 'udev)
39259 (list (service-extension shepherd-root-service-type
39260 udev-shepherd-service)))
39262 (compose concatenate) ;concatenate the list of rules
39263 (extend (lambda (config rules)
39265 (($ <udev-configuration> udev initial-rules)
39266 (udev-configuration
39267 (udev udev) ;the udev package to use
39268 (rules (append initial-rules rules)))))))))
39271 This is the service type for the
39272 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
39273 management daemon}. Compared to the previous example, in addition to an
39274 extension of @code{shepherd-root-service-type}, we see two new fields:
39278 This is the procedure to @dfn{compose} the list of extensions to
39279 services of this type.
39281 Services can extend the udev service by passing it lists of rules; we
39282 compose those extensions simply by concatenating them.
39285 This procedure defines how the value of the service is @dfn{extended} with
39286 the composition of the extensions.
39288 Udev extensions are composed into a list of rules, but the udev service
39289 value is itself a @code{<udev-configuration>} record. So here, we
39290 extend that record by appending the list of rules it contains to the
39291 list of contributed rules.
39294 This is a string giving an overview of the service type. The string can
39295 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
39296 @command{guix system search} command searches these strings and displays
39297 them (@pxref{Invoking guix system}).
39300 There can be only one instance of an extensible service type such as
39301 @code{udev-service-type}. If there were more, the
39302 @code{service-extension} specifications would be ambiguous.
39304 Still here? The next section provides a reference of the programming
39305 interface for services.
39307 @node Service Reference
39308 @subsection Service Reference
39310 We have seen an overview of service types (@pxref{Service Types and
39311 Services}). This section provides a reference on how to manipulate
39312 services and service types. This interface is provided by the
39313 @code{(gnu services)} module.
39315 @deffn {Scheme Procedure} service @var{type} [@var{value}]
39316 Return a new service of @var{type}, a @code{<service-type>} object (see
39317 below). @var{value} can be any object; it represents the parameters of
39318 this particular service instance.
39320 When @var{value} is omitted, the default value specified by @var{type}
39321 is used; if @var{type} does not specify a default value, an error is
39324 For instance, this:
39327 (service openssh-service-type)
39331 is equivalent to this:
39334 (service openssh-service-type
39335 (openssh-configuration))
39338 In both cases the result is an instance of @code{openssh-service-type}
39339 with the default configuration.
39342 @deffn {Scheme Procedure} service? @var{obj}
39343 Return true if @var{obj} is a service.
39346 @deffn {Scheme Procedure} service-kind @var{service}
39347 Return the type of @var{service}---i.e., a @code{<service-type>} object.
39350 @deffn {Scheme Procedure} service-value @var{service}
39351 Return the value associated with @var{service}. It represents its
39355 Here is an example of how a service is created and manipulated:
39359 (service nginx-service-type
39360 (nginx-configuration
39362 (log-directory log-directory)
39363 (run-directory run-directory)
39364 (file config-file))))
39369 (eq? (service-kind s) nginx-service-type)
39373 The @code{modify-services} form provides a handy way to change the
39374 parameters of some of the services of a list such as
39375 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
39376 evaluates to a list of services. Of course, you could always use
39377 standard list combinators such as @code{map} and @code{fold} to do that
39378 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
39379 @code{modify-services} simply provides a more concise form for this
39382 @deffn {Scheme Syntax} modify-services @var{services} @
39383 (@var{type} @var{variable} => @var{body}) @dots{}
39385 Modify the services listed in @var{services} according to the given
39386 clauses. Each clause has the form:
39389 (@var{type} @var{variable} => @var{body})
39392 where @var{type} is a service type---e.g.,
39393 @code{guix-service-type}---and @var{variable} is an identifier that is
39394 bound within the @var{body} to the service parameters---e.g., a
39395 @code{guix-configuration} instance---of the original service of that
39398 The @var{body} should evaluate to the new service parameters, which will
39399 be used to configure the new service. This new service will replace the
39400 original in the resulting list. Because a service's service parameters
39401 are created using @code{define-record-type*}, you can write a succinct
39402 @var{body} that evaluates to the new service parameters by using the
39403 @code{inherit} feature that @code{define-record-type*} provides.
39405 Clauses can also have the following form:
39408 (delete @var{type})
39411 Such a clause removes all services of the given @var{type} from
39414 @xref{Using the Configuration System}, for example usage.
39418 Next comes the programming interface for service types. This is
39419 something you want to know when writing new service definitions, but not
39420 necessarily when simply looking for ways to customize your
39421 @code{operating-system} declaration.
39423 @deftp {Data Type} service-type
39424 @cindex service type
39425 This is the representation of a @dfn{service type} (@pxref{Service Types
39430 This is a symbol, used only to simplify inspection and debugging.
39432 @item @code{extensions}
39433 A non-empty list of @code{<service-extension>} objects (see below).
39435 @item @code{compose} (default: @code{#f})
39436 If this is @code{#f}, then the service type denotes services that cannot
39437 be extended---i.e., services that do not receive ``values'' from other
39440 Otherwise, it must be a one-argument procedure. The procedure is called
39441 by @code{fold-services} and is passed a list of values collected from
39442 extensions. It may return any single value.
39444 @item @code{extend} (default: @code{#f})
39445 If this is @code{#f}, services of this type cannot be extended.
39447 Otherwise, it must be a two-argument procedure: @code{fold-services}
39448 calls it, passing it the initial value of the service as the first
39449 argument and the result of applying @code{compose} to the extension
39450 values as the second argument. It must return a value that is a valid
39451 parameter value for the service instance.
39453 @item @code{description}
39454 This is a string, possibly using Texinfo markup, describing in a couple
39455 of sentences what the service is about. This string allows users to
39456 find about the service through @command{guix system search}
39457 (@pxref{Invoking guix system}).
39459 @item @code{default-value} (default: @code{&no-default-value})
39460 The default value associated for instances of this service type. This
39461 allows users to use the @code{service} form without its second argument:
39464 (service @var{type})
39467 The returned service in this case has the default value specified by
39471 @xref{Service Types and Services}, for examples.
39474 @deffn {Scheme Procedure} service-extension @var{target-type} @
39476 Return a new extension for services of type @var{target-type}.
39477 @var{compute} must be a one-argument procedure: @code{fold-services}
39478 calls it, passing it the value associated with the service that provides
39479 the extension; it must return a valid value for the target service.
39482 @deffn {Scheme Procedure} service-extension? @var{obj}
39483 Return true if @var{obj} is a service extension.
39486 Occasionally, you might want to simply extend an existing service. This
39487 involves creating a new service type and specifying the extension of
39488 interest, which can be verbose; the @code{simple-service} procedure
39489 provides a shorthand for this.
39491 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
39492 Return a service that extends @var{target} with @var{value}. This works
39493 by creating a singleton service type @var{name}, of which the returned
39494 service is an instance.
39496 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
39500 (simple-service 'my-mcron-job mcron-service-type
39501 #~(job '(next-hour (3)) "guix gc -F 2G"))
39505 At the core of the service abstraction lies the @code{fold-services}
39506 procedure, which is responsible for ``compiling'' a list of services
39507 down to a single directory that contains everything needed to boot and
39508 run the system---the directory shown by the @command{guix system build}
39509 command (@pxref{Invoking guix system}). In essence, it propagates
39510 service extensions down the service graph, updating each node parameters
39511 on the way, until it reaches the root node.
39513 @deffn {Scheme Procedure} fold-services @var{services} @
39514 [#:target-type @var{system-service-type}]
39515 Fold @var{services} by propagating their extensions down to the root of
39516 type @var{target-type}; return the root service adjusted accordingly.
39519 Lastly, the @code{(gnu services)} module also defines several essential
39520 service types, some of which are listed below.
39522 @defvr {Scheme Variable} system-service-type
39523 This is the root of the service graph. It produces the system directory
39524 as returned by the @command{guix system build} command.
39527 @defvr {Scheme Variable} boot-service-type
39528 The type of the ``boot service'', which produces the @dfn{boot script}.
39529 The boot script is what the initial RAM disk runs when booting.
39532 @defvr {Scheme Variable} etc-service-type
39533 The type of the @file{/etc} service. This service is used to create
39534 files under @file{/etc} and can be extended by
39535 passing it name/file tuples such as:
39538 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
39541 In this example, the effect would be to add an @file{/etc/issue} file
39542 pointing to the given file.
39545 @defvr {Scheme Variable} setuid-program-service-type
39546 Type for the ``setuid-program service''. This service collects lists of
39547 executable file names, passed as gexps, and adds them to the set of
39548 setuid and setgid programs on the system (@pxref{Setuid Programs}).
39551 @defvr {Scheme Variable} profile-service-type
39552 Type of the service that populates the @dfn{system profile}---i.e., the
39553 programs under @file{/run/current-system/profile}. Other services can
39554 extend it by passing it lists of packages to add to the system profile.
39557 @cindex provenance tracking, of the operating system
39558 @anchor{provenance-service-type}
39559 @defvr {Scheme Variable} provenance-service-type
39560 This is the type of the service that records @dfn{provenance meta-data}
39561 in the system itself. It creates several files under
39562 @file{/run/current-system}:
39566 This is a ``channel file'' that can be passed to @command{guix pull -C}
39567 or @command{guix time-machine -C}, and which describes the channels used
39568 to build the system, if that information was available
39569 (@pxref{Channels}).
39571 @item configuration.scm
39572 This is the file that was passed as the value for this
39573 @code{provenance-service-type} service. By default, @command{guix
39574 system reconfigure} automatically passes the OS configuration file it
39575 received on the command line.
39578 This contains the same information as the two other files but in a
39579 format that is more readily processable.
39582 In general, these two pieces of information (channels and configuration
39583 file) are enough to reproduce the operating system ``from source''.
39586 This information is necessary to rebuild your operating system, but it
39587 is not always sufficient. In particular, @file{configuration.scm}
39588 itself is insufficient if it is not self-contained---if it refers to
39589 external Guile modules or to extra files. If you want
39590 @file{configuration.scm} to be self-contained, we recommend that modules
39591 or files it refers to be part of a channel.
39593 Besides, provenance meta-data is ``silent'' in the sense that it does
39594 not change the bits contained in your system, @emph{except for the
39595 meta-data bits themselves}. Two different OS configurations or sets of
39596 channels can lead to the same system, bit-for-bit; when
39597 @code{provenance-service-type} is used, these two systems will have
39598 different meta-data and thus different store file names, which makes
39599 comparison less trivial.
39602 This service is automatically added to your operating system
39603 configuration when you use @command{guix system reconfigure},
39604 @command{guix system init}, or @command{guix deploy}.
39607 @defvr {Scheme Variable} linux-loadable-module-service-type
39608 Type of the service that collects lists of packages containing
39609 kernel-loadable modules, and adds them to the set of kernel-loadable
39612 This service type is intended to be extended by other service types,
39616 (simple-service 'installing-module
39617 linux-loadable-module-service-type
39618 (list module-to-install-1
39619 module-to-install-2))
39622 This does not actually load modules at bootup, only adds it to the
39623 kernel profile so that it @emph{can} be loaded by other means.
39626 @node Shepherd Services
39627 @subsection Shepherd Services
39629 @cindex shepherd services
39631 @cindex init system
39632 The @code{(gnu services shepherd)} module provides a way to define
39633 services managed by the GNU@tie{}Shepherd, which is the
39634 initialization system---the first process that is started when the
39635 system boots, also known as PID@tie{}1
39636 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
39638 Services in the Shepherd can depend on each other. For instance, the
39639 SSH daemon may need to be started after the syslog daemon has been
39640 started, which in turn can only happen once all the file systems have
39641 been mounted. The simple operating system defined earlier (@pxref{Using
39642 the Configuration System}) results in a service graph like this:
39644 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
39646 You can actually generate such a graph for any operating system
39647 definition using the @command{guix system shepherd-graph} command
39648 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
39650 The @code{%shepherd-root-service} is a service object representing
39651 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
39652 by passing it lists of @code{<shepherd-service>} objects.
39654 @deftp {Data Type} shepherd-service
39655 The data type representing a service managed by the Shepherd.
39658 @item @code{provision}
39659 This is a list of symbols denoting what the service provides.
39661 These are the names that may be passed to @command{herd start},
39662 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
39663 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
39664 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
39666 @item @code{requirement} (default: @code{'()})
39667 List of symbols denoting the Shepherd services this one depends on.
39669 @cindex one-shot services, for the Shepherd
39670 @item @code{one-shot?} (default: @code{#f})
39671 Whether this service is @dfn{one-shot}. One-shot services stop immediately
39672 after their @code{start} action has completed. @xref{Slots of services,,,
39673 shepherd, The GNU Shepherd Manual}, for more info.
39675 @item @code{respawn?} (default: @code{#t})
39676 Whether to restart the service when it stops, for instance when the
39677 underlying process dies.
39680 @itemx @code{stop} (default: @code{#~(const #f)})
39681 The @code{start} and @code{stop} fields refer to the Shepherd's
39682 facilities to start and stop processes (@pxref{Service De- and
39683 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
39684 G-expressions that get expanded in the Shepherd configuration file
39685 (@pxref{G-Expressions}).
39687 @item @code{actions} (default: @code{'()})
39688 @cindex actions, of Shepherd services
39689 This is a list of @code{shepherd-action} objects (see below) defining
39690 @dfn{actions} supported by the service, in addition to the standard
39691 @code{start} and @code{stop} actions. Actions listed here become available as
39692 @command{herd} sub-commands:
39695 herd @var{action} @var{service} [@var{arguments}@dots{}]
39698 @item @code{auto-start?} (default: @code{#t})
39699 Whether this service should be started automatically by the Shepherd. If it
39700 is @code{#f} the service has to be started manually with @code{herd start}.
39702 @item @code{documentation}
39703 A documentation string, as shown when running:
39706 herd doc @var{service-name}
39709 where @var{service-name} is one of the symbols in @code{provision}
39710 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
39712 @item @code{modules} (default: @code{%default-modules})
39713 This is the list of modules that must be in scope when @code{start} and
39714 @code{stop} are evaluated.
39719 The example below defines a Shepherd service that spawns
39720 @command{syslogd}, the system logger from the GNU Networking Utilities
39721 (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
39725 (let ((config (plain-file "syslogd.conf" "@dots{}")))
39727 (documentation "Run the syslog daemon (syslogd).")
39728 (provision '(syslogd))
39729 (requirement '(user-processes))
39730 (start #~(make-forkexec-constructor
39731 (list #$(file-append inetutils "/libexec/syslogd")
39732 "--rcfile" #$config)
39733 #:pid-file "/var/run/syslog.pid"))
39734 (stop #~(make-kill-destructor))))
39737 Key elements in this example are the @code{start} and @code{stop}
39738 fields: they are @dfn{staged} code snippets that use the
39739 @code{make-forkexec-constructor} procedure provided by the Shepherd and
39740 its dual, @code{make-kill-destructor} (@pxref{Service De- and
39741 Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
39742 field will have @command{shepherd} spawn @command{syslogd} with the
39743 given option; note that we pass @code{config} after @option{--rcfile},
39744 which is a configuration file declared above (contents of this file are
39745 omitted). Likewise, the @code{stop} field tells how this service is to
39746 be stopped; in this case, it is stopped by making the @code{kill} system
39747 call on its PID@. Code staging is achieved using G-expressions:
39748 @code{#~} stages code, while @code{#$} ``escapes'' back to host code
39749 (@pxref{G-Expressions}).
39751 @deftp {Data Type} shepherd-action
39752 This is the data type that defines additional actions implemented by a
39753 Shepherd service (see above).
39757 Symbol naming the action.
39759 @item documentation
39760 This is a documentation string for the action. It can be viewed by running:
39763 herd doc @var{service} action @var{action}
39767 This should be a gexp that evaluates to a procedure of at least one argument,
39768 which is the ``running value'' of the service (@pxref{Slots of services,,,
39769 shepherd, The GNU Shepherd Manual}).
39772 The following example defines an action called @code{say-hello} that kindly
39778 (documentation "Say hi!")
39779 (procedure #~(lambda (running . args)
39780 (format #t "Hello, friend! arguments: ~s\n"
39785 Assuming this action is added to the @code{example} service, then you can do:
39788 # herd say-hello example
39789 Hello, friend! arguments: ()
39790 # herd say-hello example a b c
39791 Hello, friend! arguments: ("a" "b" "c")
39794 This, as you can see, is a fairly sophisticated way to say hello.
39795 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
39799 @defvr {Scheme Variable} shepherd-root-service-type
39800 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
39802 This is the service type that extensions target when they want to create
39803 shepherd services (@pxref{Service Types and Services}, for an example).
39804 Each extension must pass a list of @code{<shepherd-service>}. Its
39805 value must be a @code{shepherd-configuration}, as described below.
39808 @deftp {Data Type} shepherd-configuration
39809 This data type represents the Shepherd's configuration.
39812 @item shepherd (default: @code{shepherd})
39813 The Shepherd package to use.
39815 @item services (default: @code{'()})
39816 A list of @code{<shepherd-service>} to start.
39817 You should probably use the service extension
39818 mechanism instead (@pxref{Shepherd Services}).
39822 The following example specifies the Shepherd package for the operating
39828 (services (append (list openssh-service-type))
39832 ;; Use own Shepherd package.
39833 (essential-services
39834 (modify-services (operating-system-default-essential-services
39835 this-operating-system)
39836 (shepherd-root-service-type config => (shepherd-configuration
39838 (shepherd my-shepherd))))))
39841 @defvr {Scheme Variable} %shepherd-root-service
39842 This service represents PID@tie{}1.
39845 @node Complex Configurations
39846 @subsection Complex Configurations
39847 @cindex complex configurations
39848 Some programs might have rather complex configuration files or formats,
39849 and to make it easier to create Scheme bindings for these configuration
39850 files, you can use the utilities defined in the @code{(gnu services
39851 configuration)} module.
39853 The main utility is the @code{define-configuration} macro, which you
39854 will use to define a Scheme record type (@pxref{Record Overview,,,
39855 guile, GNU Guile Reference Manual}). The Scheme record will be
39856 serialized to a configuration file by using @dfn{serializers}, which are
39857 procedures that take some kind of Scheme value and returns a
39858 G-expression (@pxref{G-Expressions}), which should, once serialized to
39859 the disk, return a string. More details are listed below.
39861 @deffn {Scheme Syntax} define-configuration @var{name} @var{clause1} @
39863 Create a record type named @code{@var{name}} that contains the
39864 fields found in the clauses.
39866 A clause can have one of the following forms:
39870 (@var{type} @var{default-value})
39871 @var{documentation})
39874 (@var{type} @var{default-value})
39875 @var{documentation}
39880 @var{documentation})
39884 @var{documentation}
39888 @var{field-name} is an identifier that denotes the name of the field in
39889 the generated record.
39891 @var{type} is the type of the value corresponding to @var{field-name};
39892 since Guile is untyped, a predicate
39893 procedure---@code{@var{type}?}---will be called on the value
39894 corresponding to the field to ensure that the value is of the correct
39895 type. This means that if say, @var{type} is @code{package}, then a
39896 procedure named @code{package?} will be applied on the value to make
39897 sure that it is indeed a @code{<package>} object.
39899 @var{default-value} is the default value corresponding to the field; if
39900 none is specified, the user is forced to provide a value when creating
39901 an object of the record type.
39903 @c XXX: Should these be full sentences or are they allow to be very
39904 @c short like package synopses?
39905 @var{documentation} is a string formatted with Texinfo syntax which
39906 should provide a description of what setting this field does.
39908 @var{serializer} is the name of a procedure which takes two arguments,
39909 the first is the name of the field, and the second is the value
39910 corresponding to the field. The procedure should return a string or
39911 G-expression (@pxref{G-Expressions}) that represents the content that
39912 will be serialized to the configuration file. If none is specified, a
39913 procedure of the name @code{serialize-@var{type}} will be used.
39915 A simple serializer procedure could look like this:
39918 (define (serialize-boolean field-name value)
39919 (let ((value (if value "true" "false")))
39920 #~(string-append #$field-name #$value)))
39923 In some cases multiple different configuration records might be defined
39924 in the same file, but their serializers for the same type might have to
39925 be different, because they have different configuration formats. For
39926 example, the @code{serialize-boolean} procedure for the Getmail service
39927 would have to be different from the one for the Transmission service. To
39928 make it easier to deal with this situation, one can specify a serializer
39929 prefix by using the @code{prefix} literal in the
39930 @code{define-configuration} form. This means that one doesn't have to
39931 manually specify a custom @var{serializer} for every field.
39934 (define (foo-serialize-string field-name value)
39937 (define (bar-serialize-string field-name value)
39940 (define-configuration foo-configuration
39943 "The name of label.")
39946 (define-configuration bar-configuration
39949 "The IPv4 address for this device.")
39953 However, in some cases you might not want to serialize any of the values
39954 of the record, to do this, you can use the @code{no-serialization}
39955 literal. There is also the @code{define-configuration/no-serialization}
39956 macro which is a shorthand of this.
39959 ;; Nothing will be serialized to disk.
39960 (define-configuration foo-configuration
39963 "Some documentation.")
39964 (no-serialization))
39966 ;; The same thing as above.
39967 (define-configuration/no-serialization bar-configuration
39970 "Some documentation."))
39974 @deffn {Scheme Syntax} define-maybe @var{type}
39975 Sometimes a field should not be serialized if the user doesn’t specify a
39976 value. To achieve this, you can use the @code{define-maybe} macro to
39977 define a ``maybe type''; if the value of a maybe type is left unset, or
39978 is set to the @code{%unset-value} value, then it will not be serialized.
39980 When defining a ``maybe type'', the corresponding serializer for the
39981 regular type will be used by default. For example, a field of type
39982 @code{maybe-string} will be serialized using the @code{serialize-string}
39983 procedure by default, you can of course change this by specifying a
39984 custom serializer procedure. Likewise, the type of the value would have
39985 to be a string, or left unspecified.
39988 (define-maybe string)
39990 (define (serialize-string field-name value)
39993 (define-configuration baz-configuration
39995 ;; If set to a string, the `serialize-string' procedure will be used
39996 ;; to serialize the string. Otherwise this field is not serialized.
39998 "The name of this module."))
40001 Like with @code{define-configuration}, one can set a prefix for the
40002 serializer name by using the @code{prefix} literal.
40005 (define-maybe integer
40008 (define (baz-serialize-integer field-name value)
40012 There is also the @code{no-serialization} literal, which when set means
40013 that no serializer will be defined for the ``maybe type'', regardless of
40014 whether its value is set or not.
40015 @code{define-maybe/no-serialization} is a shorthand for specifying the
40016 @code{no-serialization} literal.
40019 (define-maybe/no-serialization symbol)
40021 (define-configuration/no-serialization test-configuration
40028 @deffn (Scheme Procedure) maybe-value-set? @var{value}
40029 Predicate to check whether a user explicitly specified the value of a
40033 @deffn {Scheme Procedure} serialize-configuration @var{configuration} @
40035 Return a G-expression that contains the values corresponding to the
40036 @var{fields} of @var{configuration}, a record that has been generated by
40037 @code{define-configuration}. The G-expression can then be serialized to
40038 disk by using something like @code{mixed-text-file}.
40041 @deffn {Scheme Procedure} empty-serializer @var{field-name} @var{value}
40042 A serializer that just returns an empty string. The
40043 @code{serialize-package} procedure is an alias for this.
40046 Once you have defined a configuration record, you will most likely also
40047 want to document it so that other people know to use it. To help with
40048 that, there are two procedures, both of which are documented below.
40050 @deffn {Scheme Procedure} generate-documentation @var{documentation} @
40051 @var{documentation-name}
40052 Generate a Texinfo fragment from the docstrings in @var{documentation},
40053 a list of @code{(@var{label} @var{fields} @var{sub-documentation} ...)}.
40054 @var{label} should be a symbol and should be the name of the
40055 configuration record. @var{fields} should be a list of all the fields
40056 available for the configuration record.
40058 @var{sub-documentation} is a @code{(@var{field-name}
40059 @var{configuration-name})} tuple. @var{field-name} is the name of the
40060 field which takes another configuration record as its value, and
40061 @var{configuration-name} is the name of that configuration record.
40063 @var{sub-documentation} is only needed if there are nested configuration
40064 records. For example, the @code{getmail-configuration} record
40065 (@pxref{Mail Services}) accepts a @code{getmail-configuration-file}
40066 record in one of its @code{rcfile} field, therefore documentation for
40067 @code{getmail-configuration-file} is nested in
40068 @code{getmail-configuration}.
40071 (generate-documentation
40072 `((getmail-configuration ,getmail-configuration-fields
40073 (rcfile getmail-configuration-file))
40075 'getmail-configuration)
40078 @var{documentation-name} should be a symbol and should be the name of
40079 the configuration record.
40083 @deffn {Scheme Procedure} configuration->documentation
40084 @var{configuration-symbol}
40085 Take @var{configuration-symbol}, the symbol corresponding to the name
40086 used when defining a configuration record with
40087 @code{define-configuration}, and print the Texinfo documentation of its
40088 fields. This is useful if there aren’t any nested configuration records
40089 since it only prints the documentation for the top-level fields.
40092 As of right now, there is no automated way to generate documentation for
40093 configuration records and put them in the manual. Instead, every
40094 time you make a change to the docstrings of a configuration record, you
40095 have to manually call @code{generate-documentation} or
40096 @code{configuration->documentation}, and paste the output into the
40097 @file{doc/guix.texi} file.
40099 @c TODO: Actually test this
40100 Below is an example of a record type created using
40101 @code{define-configuration} and friends.
40104 (use-modules (gnu services)
40106 (gnu services configuration)
40110 ;; Turn field names, which are Scheme symbols into strings
40111 (define (uglify-field-name field-name)
40112 (let ((str (symbol->string field-name)))
40113 ;; field? -> is-field
40114 (if (string-suffix? "?" str)
40115 (string-append "is-" (string-drop-right str 1))
40118 (define (serialize-string field-name value)
40119 #~(string-append #$(uglify-field-name field-name) " = " #$value "\n"))
40121 (define (serialize-integer field-name value)
40122 (serialize-string field-name (number->string value)))
40124 (define (serialize-boolean field-name value)
40125 (serialize-string field-name (if value "true" "false")))
40127 (define (serialize-contact-name field-name value)
40128 #~(string-append "\n[" #$value "]\n"))
40130 (define (list-of-contact-configurations? lst)
40131 (every contact-configuration? lst))
40133 (define (serialize-list-of-contact-configurations field-name value)
40134 #~(string-append #$@@(map (cut serialize-configuration <>
40135 contact-configuration-fields)
40138 (define (serialize-contacts-list-configuration configuration)
40141 #~(string-append "[Owner]\n"
40142 #$(serialize-configuration
40143 configuration contacts-list-configuration-fields))))
40145 (define-maybe integer)
40146 (define-maybe string)
40148 (define-configuration contact-configuration
40151 "The name of the contact."
40152 serialize-contact-name)
40155 "The person's phone number.")
40158 "The person's email address.")
40161 "Whether the person is married."))
40163 (define-configuration contacts-list-configuration
40166 "The name of the owner of this contact list.")
40169 "The owner's email address.")
40171 (list-of-contact-configurations '())
40172 "A list of @@code@{contact-configuation@} records which contain
40173 information about all your contacts."))
40176 A contacts list configuration could then be created like this:
40179 (define my-contacts
40180 (contacts-list-configuration
40182 (email "alice@@example.org")
40184 (list (contact-configuration
40186 (phone-number 1234)
40187 (email "bob@@gnu.org")
40189 (contact-configuration
40191 (phone-number 0000)
40195 After serializing the configuration to disk, the resulting file would
40201 email = alice@@example.org
40204 phone-number = 1234
40205 email = bob@@gnu.org
40214 @node Home Configuration
40215 @chapter Home Configuration
40216 @cindex home configuration
40217 Guix supports declarative configuration of @dfn{home environments} by
40218 utilizing the configuration mechanism described in the previous chapter
40219 (@pxref{Defining Services}), but for user's dotfiles and packages. It
40220 works both on Guix System and foreign distros and allows users to
40221 declare all the packages and services that should be installed and
40222 configured for the user. Once a user has written a file containing
40223 @code{home-environment} record, such a configuration can be
40224 @dfn{instantiated} by an unprivileged user with the @command{guix home}
40225 command (@pxref{Invoking guix home}).
40226 @c Maybe later, it will be possible to make home configuration a part of
40227 @c system configuration to make everything managed by guix system.
40230 The functionality described in this section is still under development
40231 and is subject to change. Get in touch with us on
40232 @email{guix-devel@@gnu.org}!
40235 The user's home environment usually consists of three basic parts:
40236 software, configuration, and state. Software in mainstream distros are
40237 usually installed system-wide, but with GNU Guix most software packages
40238 can be installed on a per-user basis without needing root privileges,
40239 and are thus considered part of the user’s @dfn{home environment}.
40240 Packages on their own are not very useful in many cases, because often they
40241 require some additional configuration, usually config files that reside
40242 in @env{XDG_CONFIG_HOME} (@file{~/.config} by default) or other
40243 directories. Everything else can be considered state, like media files,
40244 application databases, and logs.
40246 Using Guix for managing home environments provides a number of
40251 @item All software can be configured in one language (Guile Scheme),
40252 this gives users the ability to share values between configurations of
40253 different programs.
40255 @item A well-defined home environment is self-contained and can be
40256 created in a declarative and reproducible way---there is no need to grab
40257 external binaries or manually edit some configuration file.
40259 @item After every @command{guix home reconfigure} invocation, a new home
40260 environment generation will be created. This means that users can
40261 rollback to a previous home environment generation so they don’t have to
40262 worry about breaking their configuration.
40264 @item It is possible to manage stateful data with Guix Home, this
40265 includes the ability to automatically clone Git repositories on the
40266 initial setup of the machine, and periodically running commands like
40267 @command{rsync} to sync data with another host. This functionality is
40268 still in an experimental stage, though.
40273 * Declaring the Home Environment:: Customizing your Home.
40274 * Configuring the Shell:: Enabling home environment.
40275 * Home Services:: Specifying home services.
40276 * Invoking guix home:: Instantiating a home configuration.
40279 @node Declaring the Home Environment
40280 @section Declaring the Home Environment
40281 The home environment is configured by providing a
40282 @code{home-environment} declaration in a file that can be passed to the
40283 @command{guix home} command (@pxref{Invoking guix home}). The easiest
40284 way to get started is by generating an initial configuration with
40285 @command{guix home import}:
40288 guix home import ~/src/guix-config
40291 The @command{guix home import} command reads some of the ``dot files''
40292 such as @file{~/.bashrc} found in your home directory and copies them to
40293 the given directory, @file{~/src/guix-config} in this case; it also
40294 reads the contents of your profile, @file{~/.guix-profile}, and, based
40295 on that, it populates @file{~/src/guix-config/home-configuration.scm}
40296 with a Home configuration that resembles your current configuration.
40298 A simple setup can include Bash and a custom text configuration, like in
40299 the example below. Don't be afraid to declare home environment parts,
40300 which overlaps with your current dot files: before installing any
40301 configuration files, Guix Home will back up existing config files to a
40302 separate place in the home directory.
40305 It is highly recommended that you manage your shell or shells with Guix
40306 Home, because it will make sure that all the necessary scripts are
40307 sourced by the shell configuration file. Otherwise you will need to do
40308 it manually. (@pxref{Configuring the Shell}).
40311 @findex home-environment
40313 @include he-config-bare-bones.scm
40316 The @code{packages} field should be self-explanatory, it will install
40317 the list of packages into the user's profile. The most important field
40318 is @code{services}, it contains a list of @dfn{home services}, which are
40319 the basic building blocks of a home environment.
40321 There is no daemon (at least not necessarily) related to a home service,
40322 a home service is just an element that is used to declare part of home
40323 environment and extend other parts of it. The extension mechanism
40324 discussed in the previous chapter (@pxref{Defining Services}) should not
40325 be confused with Shepherd services (@pxref{Shepherd Services}). Using this extension
40326 mechanism and some Scheme code that glues things together gives the user
40327 the freedom to declare their own, very custom, home environments.
40329 @cindex container, for @command{guix home}
40330 Once the configuration looks good, you can first test it in a throw-away
40334 guix home container config.scm
40337 The command above spawns a shell where your home environment is running.
40338 The shell runs in a container, meaning it's isolated from the rest of
40339 the system, so it's a good way to try out your configuration---you can
40340 see if configuration bits are missing or misbehaving, if daemons get
40341 started, and so on. Once you exit that shell, you're back to the prompt
40342 of your original shell ``in the real world''.
40344 Once you have a configuration file that suits your needs, you can
40345 reconfigure your home by running:
40348 guix home reconfigure config.scm
40351 This ``builds'' your home environment and creates @file{~/.guix-home}
40352 pointing to it. Voilà!
40355 Make sure the operating system has elogind, systemd, or a similar
40356 mechanism to create the XDG run-time directory and has the
40357 @env{XDG_RUNTIME_DIR} variable set. Failing that, the
40358 @file{on-first-login} script will not execute anything, and processes
40359 like user Shepherd and its descendants will not start.
40362 @node Configuring the Shell
40363 @section Configuring the Shell
40364 This section is safe to skip if your shell or shells are managed by
40365 Guix Home. Otherwise, read it carefully.
40367 There are a few scripts that must be evaluated by a login shell to
40368 activate the home environment. The shell startup files only read by
40369 login shells often have @code{profile} suffix. For more information
40370 about login shells see @ref{Invoking Bash,,, bash, The GNU Bash
40371 Reference Manual} and see @ref{Bash Startup Files,,, bash, The GNU Bash
40374 The first script that needs to be sourced is @file{setup-environment},
40375 which sets all the necessary environment variables (including variables
40376 declared by the user) and the second one is @file{on-first-login}, which
40377 starts Shepherd for the current user and performs actions declared by
40378 other home services that extends
40379 @code{home-run-on-first-login-service-type}.
40381 Guix Home will always create @file{~/.profile}, which contains the
40385 HOME_ENVIRONMENT=$HOME/.guix-home
40386 . $HOME_ENVIRONMENT/setup-environment
40387 $HOME_ENVIRONMENT/on-first-login
40390 This makes POSIX compliant login shells activate the home environment.
40391 However, in most cases this file won't be read by most modern shells,
40392 because they are run in non POSIX mode by default and have their own
40393 @file{*profile} startup files. For example Bash will prefer
40394 @file{~/.bash_profile} in case it exists and only if it doesn't will it
40395 fallback to @file{~/.profile}. Zsh (if no additional options are
40396 specified) will ignore @file{~/.profile}, even if @file{~/.zprofile}
40399 To make your shell respect @file{~/.profile}, add @code{. ~/.profile} or
40400 @code{source ~/.profile} to the startup file for the login shell. In
40401 case of Bash, it is @file{~/.bash_profile}, and in case of Zsh, it is
40402 @file{~/.zprofile}.
40405 This step is only required if your shell is @emph{not} managed by Guix Home.
40406 Otherwise, everything will be done automatically.
40409 @node Home Services
40410 @section Home Services
40411 @cindex home services
40413 A @dfn{home service} is not necessarily something that has a daemon and
40414 is managed by Shepherd (@pxref{Jump Start,,, shepherd, The GNU Shepherd
40415 Manual}), in most cases it doesn't. It's a simple building block of the
40416 home environment, often declaring a set of packages to be installed in
40417 the home environment profile, a set of config files to be symlinked into
40418 @env{XDG_CONFIG_HOME} (@file{~/.config} by default), and environment
40419 variables to be set by a login shell.
40421 There is a service extension mechanism (@pxref{Service Composition})
40422 which allows home services to extend other home services and utilize
40423 capabilities they provide; for example: declare mcron jobs
40424 (@pxref{Top,,, mcron, GNU@tie{}Mcron}) by extending @ref{Mcron Home
40425 Service}; declare daemons by extending @ref{Shepherd Home Service}; add
40426 commands, which will be invoked on by the Bash by extending
40427 @ref{Shells Home Services, @code{home-bash-service-type}}.
40429 A good way to discover available home services is using the
40430 @command{guix home search} command (@pxref{Invoking guix home}). After
40431 the required home services are found, include its module with the
40432 @code{use-modules} form (@pxref{use-modules,, Using Guile Modules,
40433 guile, The GNU Guile Reference Manual}), or the @code{#:use-modules}
40434 directive (@pxref{define-module,, Creating Guile Modules, guile, The GNU
40435 Guile Reference Manual}) and declare a home service using the
40436 @code{service} function, or extend a service type by declaring a new
40437 service with the @code{simple-service} procedure from @code{(gnu
40441 * Essential Home Services:: Environment variables, packages, on-* scripts.
40442 * Shells: Shells Home Services. POSIX shells, Bash, Zsh.
40443 * Mcron: Mcron Home Service. Scheduled User's Job Execution.
40444 * Power Management: Power Management Home Services. Services for battery power.
40445 * Shepherd: Shepherd Home Service. Managing User's Daemons.
40446 * SSH: Secure Shell. Setting up the secure shell client.
40447 * Desktop: Desktop Home Services. Services for graphical environments.
40448 * Guix: Guix Home Services. Services for Guix.
40450 @c In addition to that Home Services can provide
40452 @node Essential Home Services
40453 @subsection Essential Home Services
40454 There are a few essential home services defined in
40455 @code{(gnu services)}, they are mostly for internal use and are required
40456 to build a home environment, but some of them will be useful for the end
40459 @cindex environment variables
40461 @defvr {Scheme Variable} home-environment-variables-service-type
40462 The service of this type will be instantiated by every home environment
40463 automatically by default, there is no need to define it, but someone may
40464 want to extend it with a list of pairs to set some environment
40468 (list ("ENV_VAR1" . "value1")
40469 ("ENV_VAR2" . "value2"))
40472 The easiest way to extend a service type, without defining a new service
40473 type is to use the @code{simple-service} helper from @code{(gnu
40477 (simple-service 'some-useful-env-vars-service
40478 home-environment-variables-service-type
40479 `(("LESSHISTFILE" . "$XDG_CACHE_HOME/.lesshst")
40480 ("SHELL" . ,(file-append zsh "/bin/zsh"))
40481 ("USELESS_VAR" . #f)
40482 ("_JAVA_AWT_WM_NONREPARENTING" . #t)))
40485 If you include such a service in you home environment definition, it
40486 will add the following content to the @file{setup-environment} script
40487 (which is expected to be sourced by the login shell):
40490 export LESSHISTFILE=$XDG_CACHE_HOME/.lesshst
40491 export SHELL=/gnu/store/2hsg15n644f0glrcbkb1kqknmmqdar03-zsh-5.8/bin/zsh
40492 export _JAVA_AWT_WM_NONREPARENTING
40496 Make sure that module @code{(gnu packages shells)} is imported with
40497 @code{use-modules} or any other way, this namespace contains the
40498 definition of the @code{zsh} package, which is used in the example
40502 The association list (@pxref{Association Lists, alists, Association
40503 Lists, guile, The GNU Guile Reference manual}) is a data structure
40504 containing key-value pairs, for
40505 @code{home-environment-variables-service-type} the key is always a
40506 string, the value can be a string, string-valued gexp
40507 (@pxref{G-Expressions}), file-like object (@pxref{G-Expressions,
40508 file-like object}) or boolean. For gexps, the variable will be set to
40509 the value of the gexp; for file-like objects, it will be set to the path
40510 of the file in the store (@pxref{The Store}); for @code{#t}, it will
40511 export the variable without any value; and for @code{#f}, it will omit
40516 @defvr {Scheme Variable} home-profile-service-type
40517 The service of this type will be instantiated by every home environment
40518 automatically, there is no need to define it, but you may want to extend
40519 it with a list of packages if you want to install additional packages
40520 into your profile. Other services, which need to make some programs
40521 available to the user will also extend this service type.
40523 The extension value is just a list of packages:
40526 (list htop vim emacs)
40529 The same approach as @code{simple-service} (@pxref{Service Reference,
40530 simple-service}) for @code{home-environment-variables-service-type} can
40531 be used here, too. Make sure that modules containing the specified
40532 packages are imported with @code{use-modules}. To find a package or
40533 information about its module use @command{guix search} (@pxref{Invoking
40534 guix package}). Alternatively, @code{specification->package} can be
40535 used to get the package record from string without importing related
40539 There are few more essential services, but users are not expected to
40542 @defvr {Scheme Variable} home-service-type
40543 The root of home services DAG, it generates a folder, which later will be
40544 symlinked to @file{~/.guix-home}, it contains configurations,
40545 profile with binaries and libraries, and some necessary scripts to glue
40549 @defvr {Scheme Variable} home-run-on-first-login-service-type
40550 The service of this type generates a Guile script, which is expected to
40551 be executed by the login shell. It is only executed if the special flag
40552 file inside @env{XDG_RUNTIME_DIR} hasn't been created, this prevents
40553 redundant executions of the script if multiple login shells are spawned.
40555 It can be extended with a gexp. However, to autostart an application,
40556 users @emph{should not} use this service, in most cases it's better to extend
40557 @code{home-shepherd-service-type} with a Shepherd service
40558 (@pxref{Shepherd Services}), or extend the shell's startup file with
40559 the required command using the appropriate service type.
40562 @defvr {Scheme Variable} home-files-service-type
40563 The service of this type allows to specify a list of files, which will
40564 go to @file{~/.guix-home/files}, usually this directory contains
40565 configuration files (to be more precise it contains symlinks to files in
40566 @file{/gnu/store}), which should be placed in @file{$XDG_CONFIG_DIR} or
40567 in rare cases in @file{$HOME}. It accepts extension values in the
40571 `((".sway/config" ,sway-file-like-object)
40572 (".tmux.conf" ,(local-file "./tmux.conf")))
40575 Each nested list contains two values: a subdirectory and file-like
40576 object. After building a home environment @file{~/.guix-home/files}
40577 will be populated with apropiate content and all nested directories will
40578 be created accordingly, however, those files won't go any further until
40579 some other service will do it. By default a
40580 @code{home-symlink-manager-service-type}, which creates necessary
40581 symlinks in home folder to files from @file{~/.guix-home/files} and
40582 backs up already existing, but clashing configs and other things, is a
40583 part of essential home services (enabled by default), but it's possible
40584 to use alternative services to implement more advanced use cases like
40585 read-only home. Feel free to experiment and share your results.
40588 @defvr {Scheme Variable} home-xdg-configuration-files-service-type
40589 The service is very similiar to @code{home-files-service-type} (and
40590 actually extends it), but used for defining files, which will go to
40591 @file{~/.guix-home/files/.config}, which will be symlinked to
40592 @file{$XDG_CONFIG_DIR} by @code{home-symlink-manager-service-type} (for
40593 example) during activation. It accepts extension values in the
40597 `(("sway/config" ,sway-file-like-object)
40598 ;; -> ~/.guix-home/files/.config/sway/config
40599 ;; -> $XDG_CONFIG_DIR/sway/config (by symlink-manager)
40600 ("tmux/tmux.conf" ,(local-file "./tmux.conf")))
40604 @defvr {Scheme Variable} home-activation-service-type
40605 The service of this type generates a guile script, which runs on every
40606 @command{guix home reconfigure} invocation or any other action, which
40607 leads to the activation of the home environment.
40610 @defvr {Scheme Variable} home-symlink-manager-service-type
40611 The service of this type generates a guile script, which will be
40612 executed during activation of home environment, and do a few following
40617 Reads the content of @file{files/} directory of current and pending home
40621 Cleans up all symlinks created by symlink-manager on previous
40622 activation. Also, sub-directories, which become empty also will be
40626 Creates new symlinks the following way: It looks @file{files/} directory
40627 (usually defined with @code{home-files-service-type},
40628 @code{home-xdg-configuration-files-service-type} and maybe some others),
40629 takes the files from @file{files/.config/} subdirectory and put
40630 respective links in @env{XDG_CONFIG_DIR}. For example symlink for
40631 @file{files/.config/sway/config} will end up in
40632 @file{$XDG_CONFIG_DIR/sway/config}. The rest files in @file{files/}
40633 outside of @file{files/.config/} subdirectory will be treated slightly
40634 different: symlink will just go to @file{$HOME}.
40635 @file{files/.some-program/config} will end up in
40636 @file{$HOME/.some-program/config}.
40639 If some sub-directories are missing, they will be created.
40642 If there is a clashing files on the way, they will be backed up.
40646 symlink-manager is a part of essential home services and is enabled and
40651 @node Shells Home Services
40655 @cindex login shell
40656 @cindex interactive shell
40660 Shells play a quite important role in the environment initialization
40661 process, you can configure them manually as described in section
40662 @ref{Configuring the Shell}, but the recommended way is to use home services
40663 listed below. It's both easier and more reliable.
40665 Each home environment instantiates
40666 @code{home-shell-profile-service-type}, which creates a
40667 @file{~/.profile} startup file for all POSIX-compatible shells. This
40668 file contains all the necessary steps to properly initialize the
40669 environment, but many modern shells like Bash or Zsh prefer their own
40670 startup files, that's why the respective home services
40671 (@code{home-bash-service-type} and @code{home-zsh-service-type}) ensure
40672 that @file{~/.profile} is sourced by @file{~/.bash_profile} and
40673 @file{~/.zprofile}, respectively.
40675 @subsubheading Shell Profile Service
40677 @deftp {Data Type} home-shell-profile-configuration
40678 Available @code{home-shell-profile-configuration} fields are:
40681 @item @code{profile} (default: @code{()}) (type: text-config)
40682 @code{home-shell-profile} is instantiated automatically by
40683 @code{home-environment}, DO NOT create this service manually, it can
40684 only be extended. @code{profile} is a list of file-like objects, which
40685 will go to @file{~/.profile}. By default @file{~/.profile} contains the
40686 initialization code which must be evaluated by the login shell to make
40687 home-environment's profile available to the user, but other commands can
40688 be added to the file if it is really necessary. In most cases shell's
40689 configuration files are preferred places for user's customizations.
40690 Extend home-shell-profile service only if you really know what you do.
40696 @subsubheading Bash Home Service
40698 @anchor{home-bash-configuration}
40699 @deftp {Data Type} home-bash-configuration
40700 Available @code{home-bash-configuration} fields are:
40703 @item @code{package} (default: @code{bash}) (type: package)
40704 The Bash package to use.
40706 @item @code{guix-defaults?} (default: @code{#t}) (type: boolean)
40707 Add sane defaults like reading @file{/etc/bashrc} and coloring the output of
40708 @command{ls} to the top of the @file{.bashrc} file.
40710 @item @code{environment-variables} (default: @code{()}) (type: alist)
40711 Association list of environment variables to set for the Bash session. The
40712 rules for the @code{home-environment-variables-service-type} apply
40713 here (@pxref{Essential Home Services}). The contents of this field will be
40714 added after the contents of the @code{bash-profile} field.
40716 @item @code{aliases} (default: @code{()}) (type: alist)
40717 Association list of aliases to set for the Bash session. The aliases
40718 will be defined after the contents of the @code{bashrc} field has been
40719 put in the @file{.bashrc} file. The alias will automatically be quoted,
40720 so something like this:
40723 '(("ls" . "ls -alF"))
40732 @item @code{bash-profile} (default: @code{()}) (type: text-config)
40733 List of file-like objects, which will be added to @file{.bash_profile}.
40734 Used for executing user's commands at start of login shell (In most
40735 cases the shell started on tty just after login). @file{.bash_login}
40736 won't be ever read, because @file{.bash_profile} always present.
40738 @item @code{bashrc} (default: @code{()}) (type: text-config)
40739 List of file-like objects, which will be added to @file{.bashrc}. Used
40740 for executing user's commands at start of interactive shell (The shell
40741 for interactive usage started by typing @code{bash} or by terminal app
40742 or any other program).
40744 @item @code{bash-logout} (default: @code{()}) (type: text-config)
40745 List of file-like objects, which will be added to @file{.bash_logout}.
40746 Used for executing user's commands at the exit of login shell. It won't
40747 be read in some cases (if the shell terminates by exec'ing another
40748 process for example).
40753 You can extend the Bash service by using the @code{home-bash-extension}
40754 configuration record, whose fields must mirror that of
40755 @code{home-bash-configuration} (@pxref{home-bash-configuration}). The
40756 contents of the extensions will be added to the end of the corresponding
40757 Bash configuration files (@pxref{Bash Startup Files,,, bash, The GNU
40758 Bash Reference Manual}.
40760 For example, here is how you would define a service that extends the
40761 Bash service such that @file{~/.bash_profile} defines an additional
40762 environment variable, @env{PS1}:
40765 (define bash-fancy-prompt-service
40766 (simple-service 'bash-fancy-prompt
40767 home-bash-service-type
40768 (home-bash-extension
40769 (environment-variables
40770 '(("PS1" . "\\u \\wλ "))))))
40773 You would then add @code{bash-fancy-prompt-service} to the list in the
40774 @code{services} field of your @code{home-environment}. The reference of
40775 @code{home-bash-extension} follows.
40777 @deftp {Data Type} home-bash-extension
40778 Available @code{home-bash-extension} fields are:
40781 @item @code{environment-variables} (default: @code{()}) (type: alist)
40782 Additional environment variables to set. These will be combined with the
40783 environment variables from other extensions and the base service to form one
40784 coherent block of environment variables.
40786 @item @code{aliases} (default: @code{()}) (type: alist)
40787 Additional aliases to set. These will be combined with the aliases from
40788 other extensions and the base service.
40790 @item @code{bash-profile} (default: @code{()}) (type: text-config)
40791 Additional text blocks to add to @file{.bash_profile}, which will be combined
40792 with text blocks from other extensions and the base service.
40794 @item @code{bashrc} (default: @code{()}) (type: text-config)
40795 Additional text blocks to add to @file{.bashrc}, which will be combined
40796 with text blocks from other extensions and the base service.
40798 @item @code{bash-logout} (default: @code{()}) (type: text-config)
40799 Additional text blocks to add to @file{.bash_logout}, which will be combined
40800 with text blocks from other extensions and the base service.
40805 @subsubheading Zsh Home Service
40807 @deftp {Data Type} home-zsh-configuration
40808 Available @code{home-zsh-configuration} fields are:
40811 @item @code{package} (default: @code{zsh}) (type: package)
40812 The Zsh package to use.
40814 @item @code{xdg-flavor?} (default: @code{#t}) (type: boolean)
40815 Place all the configs to @file{$XDG_CONFIG_HOME/zsh}. Makes
40816 @file{~/.zshenv} to set @env{ZDOTDIR} to @file{$XDG_CONFIG_HOME/zsh}.
40817 Shell startup process will continue with
40818 @file{$XDG_CONFIG_HOME/zsh/.zshenv}.
40820 @item @code{environment-variables} (default: @code{()}) (type: alist)
40821 Association list of environment variables to set for the Zsh session.
40823 @item @code{zshenv} (default: @code{()}) (type: text-config)
40824 List of file-like objects, which will be added to @file{.zshenv}. Used
40825 for setting user's shell environment variables. Must not contain
40826 commands assuming the presence of tty or producing output. Will be read
40827 always. Will be read before any other file in @env{ZDOTDIR}.
40829 @item @code{zprofile} (default: @code{()}) (type: text-config)
40830 List of file-like objects, which will be added to @file{.zprofile}. Used
40831 for executing user's commands at start of login shell (In most cases the
40832 shell started on tty just after login). Will be read before
40835 @item @code{zshrc} (default: @code{()}) (type: text-config)
40836 List of file-like objects, which will be added to @file{.zshrc}. Used
40837 for executing user's commands at start of interactive shell (The shell
40838 for interactive usage started by typing @code{zsh} or by terminal app or
40839 any other program).
40841 @item @code{zlogin} (default: @code{()}) (type: text-config)
40842 List of file-like objects, which will be added to @file{.zlogin}. Used
40843 for executing user's commands at the end of starting process of login
40846 @item @code{zlogout} (default: @code{()}) (type: text-config)
40847 List of file-like objects, which will be added to @file{.zlogout}. Used
40848 for executing user's commands at the exit of login shell. It won't be
40849 read in some cases (if the shell terminates by exec'ing another process
40856 @node Mcron Home Service
40857 @subsection Scheduled User's Job Execution
40861 @cindex scheduling jobs
40863 The @code{(gnu home services mcron)} module provides an interface to
40864 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
40865 mcron, GNU@tie{}mcron}). The information about system's mcron is
40866 applicable here (@pxref{Scheduled Job Execution}), the only difference
40867 for home services is that they have to be declared in a
40868 @code{home-environment} record instead of an @code{operating-system}
40871 @defvr {Scheme Variable} home-mcron-service-type
40872 This is the type of the @code{mcron} home service, whose value is an
40873 @code{home-mcron-configuration} object. It allows to manage scheduled
40876 This service type can be the target of a service extension that provides
40877 additional job specifications (@pxref{Service Composition}). In other
40878 words, it is possible to define services that provide additional mcron
40882 @deftp {Data Type} home-mcron-configuration
40883 Data type representing the configuration of mcron.
40886 @item @code{mcron} (default: @var{mcron})
40887 The mcron package to use.
40890 This is a list of gexps (@pxref{G-Expressions}), where each gexp
40891 corresponds to an mcron job specification (@pxref{Syntax, mcron job
40892 specifications,, mcron, GNU@tie{}mcron}).
40896 @node Power Management Home Services
40897 @subsection Power Management Home Services
40899 @cindex power management
40900 The @code{(gnu home services pm)} module provides home services
40901 pertaining to battery power.
40903 @defvr {Scheme Variable} home-batsignal-service-type
40904 Service for @code{batsignal}, a program that monitors battery levels
40905 and warns the user through desktop notifications when their battery
40906 is getting low. You can also configure a command to be run when the
40907 battery level passes a point deemed ``dangerous''. This service is
40908 configured with the @code{home-batsignal-configuration} record.
40911 @deftp {Data Type} home-batsignal-configuration
40912 Data type representing the configuration for batsignal.
40915 @item @code{warning-level} (default: @code{15})
40916 The battery level to send a warning message at.
40918 @item @code{warning-message} (default: @code{#f})
40919 The message to send as a notification when the battery level reaches
40920 the @code{warning-level}. Setting to @code{#f} uses the default
40923 @item @code{critical-level} (default: @code{5})
40924 The battery level to send a critical message at.
40926 @item @code{critical-message} (default: @code{#f})
40927 The message to send as a notification when the battery level reaches
40928 the @code{critical-level}. Setting to @code{#f} uses the default
40931 @item @code{danger-level} (default: @code{2})
40932 The battery level to run the @code{danger-command} at.
40934 @item @code{danger-command} (default: @code{#f})
40935 The command to run when the battery level reaches the @code{danger-level}.
40936 Setting to @code{#f} disables running the command entirely.
40938 @item @code{full-level} (default: @code{#f})
40939 The battery level to send a full message at. Setting to @code{#f}
40940 disables sending the full message entirely.
40942 @item @code{full-message} (default: @code{#f})
40943 The message to send as a notification when the battery level reaches
40944 the @code{full-level}. Setting to @code{#f} uses the default message.
40946 @item @code{batteries} (default: @code{'()})
40947 The batteries to monitor. Setting to @code{'()} tries to find batteries
40950 @item @code{poll-delay} (default: @code{60})
40951 The time in seconds to wait before checking the batteries again.
40953 @item @code{icon} (default: @code{#f})
40954 A file-like object to use as the icon for battery notifications. Setting
40955 to @code{#f} disables notification icons entirely.
40957 @item @code{notifications?} (default: @code{#t})
40958 Whether to send any notifications.
40960 @item @code{notifications-expire?} (default: @code{#f})
40961 Whether notifications sent expire after a time.
40963 @item @code{notification-command} (default: @code{#f})
40964 Command to use to send messages. Setting to @code{#f} sends a notification
40965 through @code{libnotify}.
40967 @item @code{ignore-missing?} (default: @code{#f})
40968 Whether to ignore missing battery errors.
40972 @node Shepherd Home Service
40973 @subsection Managing User Daemons
40975 @cindex shepherd services, for users
40976 The @code{(gnu home services shepherd)} module supports the definitions
40977 of per-user Shepherd services (@pxref{Introduction,,, shepherd, The GNU
40978 Shepherd Manual}). You extend @code{home-shepherd-service-type} with
40979 new services; Guix Home then takes care of starting the @code{shepherd}
40980 daemon for you when you log in, which in turns starts the services you
40983 @defvr {Scheme Variable} home-shepherd-service-type
40984 The service type for the userland Shepherd, which allows one to manage
40985 long-running processes or one-shot tasks. User's Shepherd is not an
40986 init process (PID 1), but almost all other information described in
40987 (@pxref{Shepherd Services}) is applicable here too.
40989 This is the service type that extensions target when they want to create
40990 shepherd services (@pxref{Service Types and Services}, for an example).
40991 Each extension must pass a list of @code{<shepherd-service>}. Its
40992 value must be a @code{home-shepherd-configuration}, as described below.
40995 @deftp {Data Type} home-shepherd-configuration
40996 This data type represents the Shepherd's configuration.
40999 @item shepherd (default: @code{shepherd})
41000 The Shepherd package to use.
41002 @item auto-start? (default: @code{#t})
41003 Whether or not to start Shepherd on first login.
41005 @item services (default: @code{'()})
41006 A list of @code{<shepherd-service>} to start.
41007 You should probably use the service extension
41008 mechanism instead (@pxref{Shepherd Services}).
41013 @subsection Secure Shell
41015 @cindex secure shell client, configuration
41016 @cindex SSH client, configuration
41017 The @uref{https://www.openssh.com, OpenSSH package} includes a client,
41018 the @command{ssh} command, that allows you to connect to remote machines
41019 using the @acronym{SSH, secure shell} protocol. With the @code{(gnu
41020 home services ssh)} module, you can set up OpenSSH so that it works in a
41021 predictable fashion, almost independently of state on the local machine.
41022 To do that, you instantiate @code{home-openssh-service-type} in your
41023 Home configuration, as explained below.
41025 @defvr {Scheme Variable} home-openssh-service-type
41026 This is the type of the service to set up the OpenSSH client. It takes
41027 care of several things:
41031 providing a @file{~/.ssh/config} file based on your configuration so
41032 that @command{ssh} knows about hosts you regularly connect to and their
41033 associated parameters;
41036 providing a @file{~/.ssh/authorized_keys}, which lists public keys that
41037 the local SSH server, @command{sshd}, may accept to connect to this user
41041 optionally providing a @file{~/.ssh/known_hosts} file so that @file{ssh}
41042 can authenticate hosts you connect to.
41045 Here is an example of a service and its configuration that you could add
41046 to the @code{services} field of your @code{home-environment}:
41049 (service home-openssh-service-type
41050 (home-openssh-configuration
41052 (list (openssh-host (name "ci.guix.gnu.org")
41054 (openssh-host (name "chbouib")
41055 (host-name "chbouib.example.org")
41056 (user "supercharlie")
41058 (authorized-keys (list (local-file "alice.pub")))))
41061 The example above lists two hosts and their parameters. For instance,
41062 running @command{ssh chbouib} will automatically connect to
41063 @code{chbouib.example.org} on port 10022, logging in as user
41064 @samp{supercharlie}. Further, it marks the public key in
41065 @file{alice.pub} as authorized for incoming connections.
41067 The value associated with a @code{home-openssh-service-type} instance
41068 must be a @code{home-openssh-configuration} record, as describe below.
41071 @deftp {Data Type} home-openssh-configuration
41072 This is the datatype representing the OpenSSH client and server
41073 configuration in one's home environment. It contains the following
41077 @item @code{hosts} (default: @code{'()})
41078 A list of @code{openssh-host} records specifying host names and
41079 associated connection parameters (see below). This host list goes into
41080 @file{~/.ssh/config}, which @command{ssh} reads at startup.
41082 @item @code{known-hosts} (default: @code{*unspecified*})
41083 This must be either:
41087 @code{*unspecified*}, in which case @code{home-openssh-service-type}
41088 leaves it up to @command{ssh} and to the user to maintain the list of
41089 known hosts at @file{~/.ssh/known_hosts}, or
41092 a list of file-like objects, in which case those are concatenated and
41093 emitted as @file{~/.ssh/known_hosts}.
41096 The @file{~/.ssh/known_hosts} contains a list of host name/host key
41097 pairs that allow @command{ssh} to authenticate hosts you connect to and
41098 to detect possible impersonation attacks. By default, @command{ssh}
41099 updates it in a @dfn{TOFU, trust-on-first-use} fashion, meaning that it
41100 records the host's key in that file the first time you connect to it.
41101 This behavior is preserved when @code{known-hosts} is set to
41102 @code{*unspecified*}.
41104 If you instead provide a list of host keys upfront in the
41105 @code{known-hosts} field, your configuration becomes self-contained and
41106 stateless: it can be replicated elsewhere or at another point in time.
41107 Preparing this list can be relatively tedious though, which is why
41108 @code{*unspecified*} is kept as a default.
41110 @item @code{authorized-keys} (default: @code{'()})
41111 This must be a list of file-like objects, each of which containing an
41112 SSH public key that should be authorized to connect to this machine.
41114 Concretely, these files are concatenated and made available as
41115 @file{~/.ssh/authorized_keys}. If an OpenSSH server, @command{sshd}, is
41116 running on this machine, then it @emph{may} take this file into account:
41117 this is what @command{sshd} does by default, but be aware that it can
41118 also be configured to ignore it.
41122 @c %start of fragment
41124 @deftp {Data Type} openssh-host
41125 Available @code{openssh-host} fields are:
41128 @item @code{name} (type: string)
41129 Name of this host declaration.
41131 @item @code{host-name} (type: maybe-string)
41132 Host name---e.g., @code{"foo.example.org"} or @code{"192.168.1.2"}.
41134 @item @code{address-family} (type: address-family)
41135 Address family to use when connecting to this host: one of
41136 @code{AF_INET} (for IPv4 only), @code{AF_INET6} (for IPv6 only), or
41137 @code{*unspecified*} (allowing any address family).
41139 @item @code{identity-file} (type: maybe-string)
41140 The identity file to use---e.g., @code{"/home/charlie/.ssh/id_ed25519"}.
41142 @item @code{port} (type: maybe-natural-number)
41143 TCP port number to connect to.
41145 @item @code{user} (type: maybe-string)
41146 User name on the remote host.
41148 @item @code{forward-x11?} (default: @code{#f}) (type: boolean)
41149 Whether to forward remote client connections to the local X11 graphical
41152 @item @code{forward-x11-trusted?} (default: @code{#f}) (type: boolean)
41153 Whether remote X11 clients have full access to the original X11
41156 @item @code{forward-agent?} (default: @code{#f}) (type: boolean)
41157 Whether the authentication agent (if any) is forwarded to the remote
41160 @item @code{compression?} (default: @code{#f}) (type: boolean)
41161 Whether to compress data in transit.
41163 @item @code{proxy-command} (type: maybe-string)
41164 The command to use to connect to the server. As an example, a command
41165 to connect via an HTTP proxy at 192.0.2.0 would be: @code{"nc -X connect
41166 -x 192.0.2.0:8080 %h %p"}.
41168 @item @code{host-key-algorithms} (type: maybe-string-list)
41169 The list of accepted host key algorithms---e.g.,
41170 @code{'("ssh-ed25519")}.
41172 @item @code{accepted-key-types} (type: maybe-string-list)
41173 The list of accepted user public key types.
41175 @item @code{extra-content} (default: @code{""}) (type: raw-configuration-string)
41176 Extra content appended as-is to this @code{Host} block in
41177 @file{~/.ssh/config}.
41184 @c %end of fragment
41187 @node Desktop Home Services
41188 @subsection Desktop Home Services
41190 The @code{(gnu home services desktop)} module provides services that you
41191 may find useful on ``desktop'' systems running a graphical user
41192 environment such as Xorg.
41194 @defvr {Scheme Variable} home-redshift-service-type
41195 This is the service type for @uref{https://github.com/jonls/redshift,
41196 Redshift}, a program that adjusts the display color temperature
41197 according to the time of day. Its associated value must be a
41198 @code{home-redshift-configuration} record, as shown below.
41200 A typical configuration, where we manually specify the latitude and
41201 longitude, might look like this:
41204 (service home-redshift-service-type
41205 (home-redshift-configuration
41206 (location-provider 'manual)
41207 (latitude 35.81) ;northern hemisphere
41208 (longitude -0.80))) ;west of Greenwich
41212 @deftp {Data Type} home-redshift-configuration
41213 Available @code{home-redshift-configuration} fields are:
41216 @item @code{redshift} (default: @code{redshift}) (type: file-like)
41217 Redshift package to use.
41219 @item @code{location-provider} (default: @code{geoclue2}) (type: symbol)
41220 Geolocation provider---@code{'manual} or @code{'geoclue2}. In the
41221 former case, you must also specify the @code{latitude} and
41222 @code{longitude} fields so Redshift can determine daytime at your place.
41223 In the latter case, the Geoclue system service must be running; it will
41224 be queried for location information.
41226 @item @code{adjustment-method} (default: @code{randr}) (type: symbol)
41227 Color adjustment method.
41229 @item @code{daytime-temperature} (default: @code{6500}) (type: integer)
41230 Daytime color temperature (kelvins).
41232 @item @code{nighttime-temperature} (default: @code{4500}) (type: integer)
41233 Nighttime color temperature (kelvins).
41235 @item @code{daytime-brightness} (type: maybe-inexact-number)
41236 Daytime screen brightness, between 0.1 and 1.0, or left unspecified.
41238 @item @code{nighttime-brightness} (type: maybe-inexact-number)
41239 Nighttime screen brightness, between 0.1 and 1.0, or left unspecified.
41241 @item @code{latitude} (type: maybe-inexact-number)
41242 Latitude, when @code{location-provider} is @code{'manual}.
41244 @item @code{longitude} (type: maybe-inexact-number)
41245 Longitude, when @code{location-provider} is @code{'manual}.
41247 @item @code{dawn-time} (type: maybe-string)
41248 Custom time for the transition from night to day in the
41249 morning---@code{"HH:MM"} format. When specified, solar elevation is not
41250 used to determine the daytime/nighttime period.
41252 @item @code{dusk-time} (type: maybe-string)
41253 Likewise, custom time for the transition from day to night in the
41256 @item @code{extra-content} (default: @code{""}) (type: raw-configuration-string)
41257 Extra content appended as-is to the Redshift configuration file. Run
41258 @command{man redshift} for more information about the configuration file
41265 @node Guix Home Services
41266 @subsection Guix Home Services
41268 The @code{(gnu home services guix)} module provides services for
41269 user-specific Guix configuration.
41271 @defvr {Scheme Variable} home-channels-service-type
41272 This is the service type for managing
41273 @file{$XDG_CONFIG_HOME/guix/channels.scm}, the file that controls the
41274 channels received on @command{guix pull} (@pxref{Channels}). Its
41275 associated value is a list of @code{channel} records, defined in the
41276 @code{(guix channels)} module.
41278 Generally, it is better to extend this service than to directly
41279 configure it, as its default value is the default guix channel(s)
41280 defined by @code{%default-channels}. If you configure this service
41281 directly, be sure to include a guix channel. @xref{Specifying
41282 Additional Channels} and @ref{Using a Custom Guix Channel} for more
41285 A typical extension for adding a channel might look like this:
41288 (simple-service 'variant-packages-service
41289 home-channels-service-type
41292 (name 'variant-packages)
41293 (url "https://example.org/variant-packages.git")))
41297 @node Invoking guix home
41298 @section Invoking @command{guix home}
41300 @cindex @command{guix home}
41302 Once you have written a home environment declaration (@pxref{Declaring
41303 the Home Environment,,,,}, it can be @dfn{instantiated} using the
41304 @command{guix home} command. The synopsis is:
41307 guix home @var{options}@dots{} @var{action} @var{file}
41310 @var{file} must be the name of a file containing a
41311 @code{home-environment} declaration. @var{action} specifies how the
41312 home environment is instantiated, but there are few auxiliary actions
41313 which don't instantiate it. Currently the following values are
41318 Display available home service type definitions that match the given
41319 regular expressions, sorted by relevance:
41322 @cindex shell-profile
41326 $ guix home search shell
41327 name: home-shell-profile
41328 location: gnu/home/services/shells.scm:100:2
41329 extends: home-files
41330 description: Create `~/.profile', which is used for environment initialization of POSIX compliant login shells.
41331 + This service type can be extended with a list of file-like objects.
41335 location: gnu/home/services/shells.scm:640:2
41336 extends: home-files home-profile
41337 description: Install and configure Fish, the friendly interactive shell.
41341 location: gnu/home/services/shells.scm:290:2
41342 extends: home-files home-profile
41343 description: Install and configure Zsh.
41347 location: gnu/home/services/shells.scm:508:2
41348 extends: home-files home-profile
41349 description: Install and configure GNU Bash.
41355 As for @command{guix search}, the result is written in
41356 @code{recutils} format, which makes it easy to filter the output
41357 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
41359 @cindex container, for @command{guix home}
41361 Spawn a shell in an isolated environment---a
41362 @dfn{container}---containing your home as specified by @var{file}.
41364 For example, this is how you would start an interactive shell in a
41365 container with your home:
41368 guix home container config.scm
41371 This is a throw-away container where you can lightheartedly fiddle with
41372 files; any changes made within the container, any process started---all
41373 this disappears as soon as you exit that shell.
41375 As with @command{guix shell}, several options control that container:
41380 Enable networking within the container (it is disabled by default).
41382 @item --expose=@var{source}[=@var{target}]
41383 @itemx --share=@var{source}[=@var{target}]
41384 As with @command{guix shell}, make directory @var{source} of the host
41385 system available as @var{target} inside the container---read-only if you
41386 pass @option{--expose}, and writable if you pass @option{--share}
41387 (@pxref{Invoking guix shell, @option{--expose} and @option{--share}}).
41390 Additionally, you can run a command in that container, instead of
41391 spawning an interactive shell. For instance, here is how you would
41392 check which Shepherd services are started in a throw-away home
41396 guix home container config.scm -- herd status
41399 The command to run in the container must come after @code{--} (double
41402 @cindex service type definition, editing
41403 @cindex editing, service type definition
41405 Edit or view the definition of the given Home service types.
41407 For example, the command below opens your editor, as specified by the
41408 @env{EDITOR} environment variable, on the definition of the
41409 @code{home-mcron} service type:
41412 guix home edit home-mcron
41416 Build the home environment described in @var{file}, and switch to it.
41417 Switching means that the activation script will be evaluated and (in
41418 basic scenario) symlinks to configuration files generated from
41419 @code{home-environment} declaration will be created in @file{~}. If the
41420 file with the same path already exists in home folder it will be moved
41421 to @file{~/@var{timestamp}-guix-home-legacy-configs-backup}, where @var{timestamp}
41422 is a current UNIX epoch time.
41425 It is highly recommended to run @command{guix pull} once before you run
41426 @command{guix home reconfigure} for the first time (@pxref{Invoking guix
41430 This effects all the configuration specified in @var{file}. The command
41431 starts Shepherd services specified in @var{file} that are not currently
41432 running; if a service is currently running, this command will arrange
41433 for it to be upgraded the next time it is stopped (e.g.@: by @code{herd
41434 stop @var{service}} or @code{herd restart @var{service}}).
41436 This command creates a new generation whose number is one greater than
41437 the current generation (as reported by @command{guix home
41438 list-generations}). If that generation already exists, it will be
41439 overwritten. This behavior mirrors that of @command{guix package}
41440 (@pxref{Invoking guix package}).
41442 @cindex provenance tracking, of the home environment
41443 Upon completion, the new home is deployed under @file{~/.guix-home}.
41444 This directory contains @dfn{provenance meta-data}: the list of channels
41445 in use (@pxref{Channels}) and @var{file} itself, when available. You
41446 can view the provenance information by running:
41452 This information is useful should you later want to inspect how this
41453 particular generation was built. In fact, assuming @var{file} is
41454 self-contained, you can later rebuild generation @var{n} of your
41455 home environment with:
41458 guix time-machine \
41459 -C /var/guix/profiles/per-user/@var{USER}/guix-home-@var{n}-link/channels.scm -- \
41461 /var/guix/profiles/per-user/@var{USER}/guix-home-@var{n}-link/configuration.scm
41465 You can think of it as some sort of built-in version control! Your
41466 home is not just a binary artifact: @emph{it carries its own source}.
41467 @c @xref{Service Reference, @code{provenance-service-type}}, for more
41468 @c information on provenance tracking.
41470 @c @footnote{This action (and the related actions
41471 @c @code{switch-generation} and @code{roll-back}) are usable after the
41472 @c home environment is initialized.}.
41474 @item switch-generation
41475 @cindex home generations
41476 Switch to an existing home generation. This action atomically switches
41477 the home profile to the specified home generation.
41479 The target generation can be specified explicitly by its generation
41480 number. For example, the following invocation would switch to home
41484 guix home switch-generation 7
41487 The target generation can also be specified relative to the current
41488 generation with the form @code{+N} or @code{-N}, where @code{+3} means
41489 ``3 generations ahead of the current generation,'' and @code{-1} means
41490 ``1 generation prior to the current generation.'' When specifying a
41491 negative value such as @code{-1}, you must precede it with @code{--} to
41492 prevent it from being parsed as an option. For example:
41495 guix home switch-generation -- -1
41498 This action will fail if the specified generation does not exist.
41501 @cindex rolling back
41502 Switch to the preceding home generation. This is the inverse
41503 of @command{reconfigure}, and it is exactly the same as invoking
41504 @command{switch-generation} with an argument of @code{-1}.
41506 @item delete-generations
41507 @cindex deleting home generations
41508 @cindex saving space
41509 Delete home generations, making them candidates for garbage collection
41510 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
41513 This works in the same way as @samp{guix package --delete-generations}
41514 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
41515 arguments, all home generations but the current one are deleted:
41518 guix home delete-generations
41521 You can also select the generations you want to delete. The example below
41522 deletes all the home generations that are more than two months old:
41525 guix home delete-generations 2m
41529 Build the derivation of the home environment, which includes all the
41530 configuration files and programs needed. This action does not actually
41534 Describe the current home generation: its file name, as well as
41535 provenance information when available.
41537 To show installed packages in the current home generation's profile, the
41538 @code{--list-installed} flag is provided, with the same syntax that is
41539 used in @command{guix package --list-installed} (@pxref{Invoking guix
41540 package}). For instance, the following command shows a table of all the
41541 packages with ``emacs'' in their name that are installed in the current
41542 home generation's profile:
41545 guix home describe --list-installed=emacs
41548 @item list-generations
41549 List a summary of each generation of the home environment available on
41550 disk, in a human-readable way. This is similar to the
41551 @option{--list-generations} option of @command{guix package}
41552 (@pxref{Invoking guix package}).
41554 Optionally, one can specify a pattern, with the same syntax that is used
41555 in @command{guix package --list-generations}, to restrict the list of
41556 generations displayed. For instance, the following command displays
41557 generations that are up to 10 days old:
41560 guix home list-generations 10d
41563 The @code{--list-installed} flag may also be specified, with the same
41564 syntax that is used in @command{guix home describe}. This may be
41565 helpful if trying to determine when a package was added to the home
41569 Generate a @dfn{home environment} from the packages in the default
41570 profile and configuration files found in the user's home directory. The
41571 configuration files will be copied to the specified directory, and a
41572 @file{home-configuration.scm} will be populated with the home
41573 environment. Note that not every home service that exists is supported
41574 (@pxref{Home Services}).
41577 $ guix home import ~/guix-config
41578 guix home: '/home/alice/guix-config' populated with all the Home configuration files
41582 And there's more! @command{guix home} also provides the following
41583 sub-commands to visualize how the services of your home environment
41584 relate to one another:
41587 @cindex service extension graph, of a home environment
41588 @item extension-graph
41589 Emit to standard output the @dfn{service extension graph} of the home
41590 environment defined in @var{file} (@pxref{Service Composition}, for more
41591 information on service extensions). By default the output is in
41592 Dot/Graphviz format, but you can choose a different format with
41593 @option{--graph-backend}, as with @command{guix graph} (@pxref{Invoking
41594 guix graph, @option{--backend}}):
41599 guix home extension-graph @var{file} | xdot -
41602 shows the extension relations among services.
41604 @cindex Shepherd dependency graph, for a home environment
41605 @item shepherd-graph
41606 Emit to standard output the @dfn{dependency graph} of shepherd services
41607 of the home environment defined in @var{file}. @xref{Shepherd
41608 Services}, for more information and for an example graph.
41610 Again, the default output format is Dot/Graphviz, but you can pass
41611 @option{--graph-backend} to select a different one.
41614 @var{options} can contain any of the common build options (@pxref{Common
41615 Build Options}). In addition, @var{options} can contain one of the
41620 @item --expression=@var{expr}
41621 @itemx -e @var{expr}
41622 Consider the home-environment @var{expr} evaluates to.
41623 This is an alternative to specifying a file which evaluates to a home
41626 @item --allow-downgrades
41627 Instruct @command{guix home reconfigure} to allow system downgrades.
41629 Just like @command{guix system}, @command{guix home reconfigure}, by
41630 default, prevents you from downgrading your home to older or unrelated
41631 revisions compared to the channel revisions that were used to deploy
41632 it---those shown by @command{guix home describe}. Using
41633 @option{--allow-downgrades} allows you to bypass that check, at the risk
41634 of downgrading your home---be careful!
41638 @node Documentation
41639 @chapter Documentation
41641 @cindex documentation, searching for
41642 @cindex searching for documentation
41643 @cindex Info, documentation format
41645 @cindex manual pages
41646 In most cases packages installed with Guix come with documentation.
41647 There are two main documentation formats: ``Info'', a browsable
41648 hypertext format used for GNU software, and ``manual pages'' (or ``man
41649 pages''), the linear documentation format traditionally found on Unix.
41650 Info manuals are accessed with the @command{info} command or with Emacs,
41651 and man pages are accessed using @command{man}.
41653 You can look for documentation of software installed on your system by
41654 keyword. For example, the following command searches for information
41655 about ``TLS'' in Info manuals:
41659 "(emacs)Network Security" -- STARTTLS
41660 "(emacs)Network Security" -- TLS
41661 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
41662 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
41667 The command below searches for the same keyword in man
41668 pages@footnote{The database searched by @command{man -k} is only created
41669 in profiles that contain the @code{man-db} package.}:
41673 SSL (7) - OpenSSL SSL/TLS library
41674 certtool (1) - GnuTLS certificate tool
41678 These searches are purely local to your computer so you have the
41679 guarantee that documentation you find corresponds to what you have
41680 actually installed, you can access it off-line, and your privacy is
41683 Once you have these results, you can view the relevant documentation by
41687 $ info "(gnutls)Core TLS API"
41697 Info manuals contain sections and indices as well as hyperlinks like
41698 those found in Web pages. The @command{info} reader (@pxref{Top, Info
41699 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
41700 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
41701 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
41702 Introduction}, for an introduction to Info navigation.
41707 The packages and systems built by Guix are intended, like most computer
41708 programs, to run on a CPU with a specific instruction set, and under a
41709 specific operating system. Those programs are often also targeting a
41710 specific kernel and system library. Those constraints are captured by
41711 Guix in @code{platform} records.
41714 * platform Reference:: Detail of platform declarations.
41715 * Supported Platforms:: Description of the supported platforms.
41718 @node platform Reference
41719 @section @code{platform} Reference
41721 The @code{platform} data type describes a @dfn{platform}: an
41722 @acronym{ISA, instruction set architecture}, combined with an operating
41723 system and possibly additional system-wide settings such as the
41724 @acronym{ABI, application binary interface}.
41726 @deftp {Data Type} platform
41727 This is the data type representing a platform.
41730 @item @code{target}
41731 This field specifies the platform's GNU triplet as a string
41732 (@pxref{Specifying Target Triplets, GNU configuration triplets,,
41733 autoconf, Autoconf}).
41735 @item @code{system}
41736 This string is the system type as it is known to Guix and passed,
41737 for instance, to the @option{--system} option of most commands.
41739 It usually has the form @code{"@var{cpu}-@var{kernel}"}, where
41740 @var{cpu} is the target CPU and @var{kernel} the target operating
41743 It can be for instance @code{"aarch64-linux"} or @code{"armhf-linux"}.
41744 You will encounter system types when you perform native builds
41745 (@pxref{Native Builds}).
41747 @item @code{linux-architecture} (default: @code{#false})
41748 This optional string field is only relevant if the kernel is Linux. In
41749 that case, it corresponds to the ARCH variable used when building Linux,
41750 @code{"mips"} for instance.
41752 @item @code{glibc-dynamic-linker}
41753 This field is the name of the GNU C Library dynamic linker for the
41754 corresponding system, as a string. It can be
41755 @code{"/lib/ld-linux-armhf.so.3"}.
41760 @node Supported Platforms
41761 @section Supported Platforms
41763 The @code{(guix platforms @dots{})} modules export the following
41764 variables, each of which is bound to a @code{platform} record.
41766 @defvr {Scheme Variable} armv7-linux
41767 Platform targeting ARM v7 CPU running GNU/Linux.
41770 @defvr {Scheme Variable} aarch64-linux
41771 Platform targeting ARM v8 CPU running GNU/Linux.
41774 @defvr {Scheme Variable} mips64-linux
41775 Platform targeting MIPS little-endian 64-bit CPU running GNU/Linux.
41778 @defvr {Scheme Variable} powerpc-linux
41779 Platform targeting PowerPC big-endian 32-bit CPU running GNU/Linux.
41782 @defvr {Scheme Variable} powerpc64le-linux
41783 Platform targeting PowerPC little-endian 64-bit CPU running GNU/Linux.
41786 @defvr {Scheme Variable} riscv64-linux
41787 Platform targeting RISC-V 64-bit CPU running GNU/Linux.
41790 @defvr {Scheme Variable} i686-linux
41791 Platform targeting x86 CPU running GNU/Linux.
41794 @defvr {Scheme Variable} x86_64-linux
41795 Platform targeting x86 64-bit CPU running GNU/Linux.
41798 @defvr {Scheme Variable} i686-mingw
41799 Platform targeting x86 CPU running Windows, with run-time support from
41803 @defvr {Scheme Variable} x86_64-mingw
41804 Platform targeting x86 64-bit CPU running Windows, with run-time support
41808 @defvr {Scheme Variable} i586-gnu
41809 Platform targeting x86 CPU running GNU/Hurd (also referred to as
41813 @node System Images
41814 @chapter Creating System Images
41816 @cindex system images
41817 When it comes to installing Guix System for the first time on a new
41818 machine, you can basically proceed in three different ways. The first
41819 one is to use an existing operating system on the machine to run the
41820 @command{guix system init} command (@pxref{Invoking guix system}). The
41821 second one, is to produce an installation image (@pxref{Building the
41822 Installation Image}). This is a bootable system which role is to
41823 eventually run @command{guix system init}. Finally, the third option
41824 would be to produce an image that is a direct instantiation of the
41825 system you wish to run. That image can then be copied on a bootable
41826 device such as an USB drive or a memory card. The target machine would
41827 then directly boot from it, without any kind of installation procedure.
41829 The @command{guix system image} command is able to turn an operating
41830 system definition into a bootable image. This command supports
41831 different image types, such as @code{efi-raw}, @code{iso9660} and
41832 @code{docker}. Any modern @code{x86_64} machine will probably be able
41833 to boot from an @code{iso9660} image. However, there are a few machines
41834 out there that require specific image types. Those machines, in general
41835 using @code{ARM} processors, may expect specific partitions at specific
41838 This chapter explains how to define customized system images and how to
41839 turn them into actual bootable images.
41842 * image Reference:: Detail of image declarations.
41843 * Instantiate an Image:: How to instantiate an image record.
41844 * image-type Reference:: Detail of image types declaration.
41845 * Image Modules:: Definition of image modules.
41848 @node image Reference
41849 @section @code{image} Reference
41851 The @code{image} record, described right after, allows you to define a
41852 customized bootable system image.
41854 @deftp {Data Type} image
41855 This is the data type representing a system image.
41858 @item @code{name} (default: @code{#false})
41859 The image name as a symbol, @code{'my-iso9660} for instance. The name
41860 is optional and it defaults to @code{#false}.
41862 @item @code{format}
41863 The image format as a symbol. The following formats are supported:
41866 @item @code{disk-image}, a raw disk image composed of one or multiple
41869 @item @code{compressed-qcow2}, a compressed qcow2 image composed of
41870 one or multiple partitions.
41872 @item @code{docker}, a Docker image.
41874 @item @code{iso9660}, an ISO-9660 image.
41876 @item @code{tarball}, a tar.gz image archive.
41878 @item @code{wsl2}, a WSL2 image.
41882 @item @code{platform} (default: @code{#false})
41883 The @code{platform} record the image is targeting (@pxref{Platforms}),
41884 @code{aarch64-linux} for instance. By default, this field is set to
41885 @code{#false} and the image will target the host platform.
41887 @item @code{size} (default: @code{'guess})
41888 The image size in bytes or @code{'guess}. The @code{'guess} symbol,
41889 which is the default, means that the image size will be inferred based
41890 on the image content.
41892 @item @code{operating-system}
41893 The image's @code{operating-system} record that is instanciated.
41895 @item @code{partition-table-type} (default: @code{'mbr})
41896 The image partition table type as a symbol. Possible values are
41897 @code{'mbr} and @code{'gpt}. It default to @code{'mbr}.
41899 @item @code{partitions} (default: @code{'()})
41900 The image partitions as a list of @code{partition} records
41901 (@pxref{partition Reference}).
41903 @item @code{compression?} (default: @code{#true})
41904 Whether the image content should be compressed, as a boolean. It
41905 defaults to @code{#true} and only applies to @code{'iso9660} image
41908 @item @code{volatile-root?} (default: @code{#true})
41909 Whether the image root partition should be made volatile, as a boolean.
41911 This is achieved by using a RAM backed file system (overlayfs) that is
41912 mounted on top of the root partition by the initrd. It defaults to
41913 @code{#true}. When set to @code{#false}, the image root partition is
41914 mounted as read-write partition by the initrd.
41916 @item @code{shared-store?} (default: @code{#false})
41917 Whether the image's store should be shared with the host system, as a
41918 boolean. This can be useful when creating images dedicated to virtual
41919 machines. When set to @code{#false}, which is the default, the image's
41920 @code{operating-system} closure is copied to the image. Otherwise, when
41921 set to @code{#true}, it is assumed that the host store will be made
41922 available at boot, using a @code{9p} mount for instance.
41924 @item @code{shared-network?} (default: @code{#false})
41925 Whether to use the host network interfaces within the image, as a
41926 boolean. This is only used for the @code{'docker} image format. It
41927 defaults to @code{#false}.
41929 @item @code{substitutable?} (default: @code{#true})
41930 Whether the image derivation should be substitutable, as a boolean. It
41931 defaults to @code{true}.
41936 @node partition Reference
41937 @subsection @code{partition} Reference
41939 In @code{image} record may contain some partitions.
41941 @deftp {Data Type} partition
41942 This is the data type representing an image partition.
41945 @item @code{size} (default: @code{'guess})
41946 The partition size in bytes or @code{'guess}. The @code{'guess} symbol,
41947 which is the default, means that the partition size will be inferred
41948 based on the partition content.
41950 @item @code{offset} (default: @code{0})
41951 The partition's start offset in bytes, relative to the image start or
41952 the previous partition end. It defaults to @code{0} which means that
41953 there is no offset applied.
41955 @item @code{file-system} (default: @code{"ext4"})
41956 The partition file system as a string, defaulting to @code{"ext4"}. The
41957 supported values are @code{"vfat"}, @code{"fat16"}, @code{"fat32"} and
41960 @item @code{file-system-options} (default: @code{'()})
41961 The partition file system creation options that should be passed to the
41962 partition creation tool, as a list of strings. This is only supported
41963 when creating @code{"ext4"} partitions.
41965 See the @code{"extended-options"} man page section of the
41966 @code{"mke2fs"} tool for a more complete reference.
41969 The partition label as a mandatory string, @code{"my-root"} for
41972 @item @code{uuid} (default: @code{#false})
41973 The partition UUID as an @code{uuid} record (@pxref{File Systems}). By
41974 default it is @code{#false}, which means that the partition creation
41975 tool will attribute a random UUID to the partition.
41977 @item @code{flags} (default: @code{'()})
41978 The partition flags as a list of symbols. Possible values are
41979 @code{'boot} and @code{'esp}. The @code{'boot} flags should be set if
41980 you want to boot from this partition. Exactly one partition should have
41981 this flag set, usually the root one. The @code{'esp} flag identifies a
41982 UEFI System Partition.
41984 @item @code{initializer} (default: @code{#false})
41985 The partition initializer procedure as a gexp. This procedure is called
41986 to populate a partition. If no initializer is passed, the
41987 @code{initialize-root-partition} procedure from the @code{(gnu build
41988 image)} module is used.
41993 @node Instantiate an Image
41994 @section Instantiate an Image
41996 Let's say you would like to create an MBR image with three distinct
42000 @item The @acronym{ESP, EFI System Partition}, a partition of
42001 40@tie{}MiB at offset 1024@tie{}KiB with a vfat file system.
42003 @item an ext4 partition of 50@tie{}MiB data file, and labeled ``data''.
42005 @item an ext4 bootable partition containing the @code{%simple-os}
42009 You would then write the following image definition in a
42010 @code{my-image.scm} file for instance.
42019 (define MiB (expt 2 20))
42022 (format 'disk-image)
42023 (operating-system %simple-os)
42028 (offset (* 1024 1024))
42030 (file-system "vfat")
42032 (initializer (gexp initialize-efi-partition)))
42036 (file-system "ext4")
42037 (initializer #~(lambda* (root . rest)
42039 (call-with-output-file
42040 (string-append root "/data")
42042 (format port "my-data"))))))
42046 (file-system "ext4")
42048 (initializer (gexp initialize-root-partition))))))
42051 Note that the first and third partitions use generic initializers
42052 procedures, initialize-efi-partition and initialize-root-partition
42053 respectively. The initialize-efi-partition installs a GRUB EFI loader
42054 that is loading the GRUB bootloader located in the root partition. The
42055 initialize-root-partition instantiates a complete system as defined by
42056 the @code{%simple-os} operating-system.
42061 guix system image my-image.scm
42064 to instantiate the @code{image} definition. That produces a disk image
42065 which has the expected structure:
42068 $ parted $(guix system image my-image.scm) print
42071 Disk /gnu/store/yhylv1bp5b2ypb97pd3bbhz6jk5nbhxw-disk-image: 1714MB
42072 Sector size (logical/physical): 512B/512B
42073 Partition Table: msdos
42076 Number Start End Size Type File system Flags
42077 1 1049kB 43.0MB 41.9MB primary fat16 esp
42078 2 43.0MB 95.4MB 52.4MB primary ext4
42079 3 95.4MB 1714MB 1619MB primary ext4 boot
42082 The size of the @code{boot} partition has been inferred to @code{1619MB}
42083 so that it is large enough to host the @code{%simple-os}
42086 You can also use existing @code{image} record definitions and inherit
42087 from them to simplify the @code{image} definition. The @code{(gnu
42088 system image)} module provides the following @code{image} definition
42091 @defvr {Scheme Variable} efi-disk-image
42092 A MBR disk-image composed of two partitions: a 64 bits ESP partition and
42093 a ROOT boot partition. This image can be used on most @code{x86_64} and
42094 @code{i686} machines, supporting BIOS or UEFI booting.
42097 @defvr {Scheme Variable} efi32-disk-image
42098 Same as @code{efi-disk-image} but with a 32 bits EFI partition.
42101 @defvr {Scheme Variable} iso9660-image
42102 An ISO-9660 image composed of a single bootable partition. This image
42103 can also be used on most @code{x86_64} and @code{i686} machines.
42106 @defvr {Scheme Variable} docker-image
42107 A Docker image that can be used to spawn a Docker container.
42110 Using the @code{efi-disk-image} we can simplify our previous
42111 @code{image} declaration this way:
42121 (define MiB (expt 2 20))
42127 (file-system "ext4")
42128 (initializer #~(lambda* (root . rest)
42130 (call-with-output-file
42131 (string-append root "/data")
42133 (format port "my-data")))))))
42136 (inherit efi-disk-image)
42137 (operating-system %simple-os)
42139 (match (image-partitions efi-disk-image)
42141 (list esp data root)))))
42144 This will give the exact same @code{image} instantiation but the
42145 @code{image} declaration is simpler.
42147 @node image-type Reference
42148 @section image-type Reference
42150 The @command{guix system image} command can, as we saw above, take a
42151 file containing an @code{image} declaration as argument and produce an
42152 actual disk image from it. The same command can also handle a file
42153 containing an @code{operating-system} declaration as argument. In that
42154 case, how is the @code{operating-system} turned into an image?
42156 That's where the @code{image-type} record intervenes. This record
42157 defines how to transform an @code{operating-system} record into an
42158 @code{image} record.
42160 @deftp {Data Type} image-type
42161 This is the data type representing an image-type.
42165 The image-type name as a mandatory symbol, @code{'efi32-raw} for
42168 @item @code{constructor}
42169 The image-type constructor, as a mandatory procedure that takes an
42170 @code{operating-system} record as argument and returns an @code{image}
42176 There are several @code{image-type} records provided by the @code{(gnu
42177 system image)} and the @code{(gnu system images @dots{})} modules.
42179 @defvr {Scheme Variable} efi-raw-image-type
42180 Build an image based on the @code{efi-disk-image} image.
42183 @defvr {Scheme Variable} efi32-raw-image-type
42184 Build an image based on the @code{efi32-disk-image} image.
42187 @defvr {Scheme Variable} qcow2-image-type
42188 Build an image based on the @code{efi-disk-image} image but with the
42189 @code{compressed-qcow2} image format.
42192 @defvr {Scheme Variable} iso-image-type
42193 Build a compressed image based on the @code{iso9660-image} image.
42196 @defvr {Scheme Variable} uncompressed-iso-image-type
42197 Build an image based on the @code{iso9660-image} image but with the
42198 @code{compression?} field set to @code{#false}.
42201 @defvr {Scheme Variable} docker-image-type
42202 Build an image based on the @code{docker-image} image.
42205 @defvr {Scheme Variable} raw-with-offset-image-type
42206 Build an MBR image with a single partition starting at a @code{1024KiB}
42207 offset. This is useful to leave some room to install a bootloader in
42211 @defvr {Scheme Variable} pinebook-pro-image-type
42212 Build an image that is targeting the Pinebook Pro machine. The MBR
42213 image contains a single partition starting at a @code{9MiB} offset. The
42214 @code{u-boot-pinebook-pro-rk3399-bootloader} bootloader will be
42215 installed in this gap.
42218 @defvr {Scheme Variable} rock64-image-type
42219 Build an image that is targeting the Rock64 machine. The MBR image
42220 contains a single partition starting at a @code{16MiB} offset. The
42221 @code{u-boot-rock64-rk3328-bootloader} bootloader will be installed in
42225 @defvr {Scheme Variable} novena-image-type
42226 Build an image that is targeting the Novena machine. It has the same
42227 characteristics as @code{raw-with-offset-image-type}.
42230 @defvr {Scheme Variable} pine64-image-type
42231 Build an image that is targeting the Pine64 machine. It has the same
42232 characteristics as @code{raw-with-offset-image-type}.
42235 @defvr {Scheme Variable} hurd-image-type
42236 Build an image that is targeting a @code{i386} machine running the Hurd
42237 kernel. The MBR image contains a single ext2 partitions with specific
42238 @code{file-system-options} flags.
42241 @defvr {Scheme Variable} hurd-qcow2-image-type
42242 Build an image similar to the one built by the @code{hurd-image-type}
42243 but with the @code{format} set to @code{'compressed-qcow2}.
42246 @defvr {Scheme Variable} wsl2-image-type
42247 Build an image for the @acronym{WSL2, Windows Subsystem for Linux 2}.
42248 It can be imported by running:
42251 wsl --import Guix ./guix ./wsl2-image.tar.gz
42257 So, if we get back to the @code{guix system image} command taking an
42258 @code{operating-system} declaration as argument. By default, the
42259 @code{efi-raw-image-type} is used to turn the provided
42260 @code{operating-system} into an actual bootable image.
42262 To use a different @code{image-type}, the @code{--image-type} option can
42263 be used. The @code{--list-image-types} option will list all the
42264 supported image types. It turns out to be a textual listing of all the
42265 @code{image-types} variables described just above (@pxref{Invoking guix
42268 @node Image Modules
42269 @section Image Modules
42271 Let's take the example of the Pine64, an ARM based machine. To be able
42272 to produce an image targeting this board, we need the following
42276 @item An @code{operating-system} record containing at least
42277 an appropriate kernel (@code{linux-libre-arm64-generic}) and bootloader
42278 @code{u-boot-pine64-lts-bootloader}) for the Pine64.
42280 @item Possibly, an @code{image-type} record providing a way to
42281 turn an @code{operating-system} record to an @code{image} record
42282 suitable for the Pine64.
42284 @item An actual @code{image} that can be instantiated with the
42285 @command{guix system image} command.
42289 The @code{(gnu system images pine64)} module provides all those
42290 elements: @code{pine64-barebones-os}, @code{pine64-image-type} and
42291 @code{pine64-barebones-raw-image} respectively.
42293 The module returns the @code{pine64-barebones-raw-image} in order for
42294 users to be able to run:
42297 guix system image gnu/system/images/pine64.scm
42300 Now, thanks to the @code{pine64-image-type} record declaring the
42301 @code{'pine64-raw} @code{image-type}, one could also prepare a
42302 @code{my-pine.scm} file with the following content:
42305 (use-modules (gnu system images pine64))
42307 (inherit pine64-barebones-os)
42308 (timezone "Europe/Athens"))
42311 to customize the @code{pine64-barebones-os}, and run:
42314 $ guix system image --image-type=pine64-raw my-pine.scm
42317 Note that there are other modules in the @code{gnu/system/images}
42318 directory targeting @code{Novena}, @code{Pine64}, @code{PinebookPro} and
42319 @code{Rock64} machines.
42321 @node Installing Debugging Files
42322 @chapter Installing Debugging Files
42324 @cindex debugging files
42325 Program binaries, as produced by the GCC compilers for instance, are
42326 typically written in the ELF format, with a section containing
42327 @dfn{debugging information}. Debugging information is what allows the
42328 debugger, GDB, to map binary code to source code; it is required to
42329 debug a compiled program in good conditions.
42331 This chapter explains how to use separate debug info when packages
42332 provide it, and how to rebuild packages with debug info when it's
42336 * Separate Debug Info:: Installing 'debug' outputs.
42337 * Rebuilding Debug Info:: Building missing debug info.
42340 @node Separate Debug Info
42341 @section Separate Debug Info
42343 The problem with debugging information is that is takes up a fair amount
42344 of disk space. For example, debugging information for the GNU C Library
42345 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
42346 debugging info of all the installed programs is usually not an option.
42347 Yet, space savings should not come at the cost of an impediment to
42348 debugging---especially in the GNU system, which should make it easier
42349 for users to exert their computing freedom (@pxref{GNU Distribution}).
42351 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
42352 mechanism that allows users to get the best of both worlds: debugging
42353 information can be stripped from the binaries and stored in separate
42354 files. GDB is then able to load debugging information from those files,
42355 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
42358 The GNU distribution takes advantage of this by storing debugging
42359 information in the @code{lib/debug} sub-directory of a separate package
42360 output unimaginatively called @code{debug} (@pxref{Packages with
42361 Multiple Outputs}). Users can choose to install the @code{debug} output
42362 of a package when they need it. For instance, the following command
42363 installs the debugging information for the GNU C Library and for GNU
42367 guix install glibc:debug guile:debug
42370 GDB must then be told to look for debug files in the user's profile, by
42371 setting the @code{debug-file-directory} variable (consider setting it
42372 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
42376 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
42379 From there on, GDB will pick up debugging information from the
42380 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
42382 Below is an alternative GDB script which is useful when working with
42383 other profiles. It takes advantage of the optional Guile integration in
42384 GDB. This snippet is included by default on Guix System in the
42385 @file{~/.gdbinit} file.
42389 (use-modules (gdb))
42390 (execute (string-append "set debug-file-directory "
42391 (or (getenv "GDB_DEBUG_FILE_DIRECTORY")
42392 "~/.guix-profile/lib/debug")))
42396 In addition, you will most likely want GDB to be able to show the source
42397 code being debugged. To do that, you will have to unpack the source
42398 code of the package of interest (obtained with @code{guix build
42399 --source}, @pxref{Invoking guix build}), and to point GDB to that source
42400 directory using the @code{directory} command (@pxref{Source Path,
42401 @code{directory},, gdb, Debugging with GDB}).
42403 @c XXX: keep me up-to-date
42404 The @code{debug} output mechanism in Guix is implemented by the
42405 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
42406 opt-in---debugging information is available only for the packages with
42407 definitions explicitly declaring a @code{debug} output. To check
42408 whether a package has a @code{debug} output, use @command{guix package
42409 --list-available} (@pxref{Invoking guix package}).
42411 Read on for how to deal with packages lacking a @code{debug} output.
42413 @node Rebuilding Debug Info
42414 @section Rebuilding Debug Info
42416 @cindex debugging info, rebuilding
42417 As we saw above, some packages, but not all, provide debugging info in a
42418 @code{debug} output. What can you do when debugging info is missing?
42419 The @option{--with-debug-info} option provides a solution to that: it
42420 allows you to rebuild the package(s) for which debugging info is
42421 missing---and only those---and to graft those onto the application
42422 you're debugging. Thus, while it's not as fast as installing a
42423 @code{debug} output, it is relatively inexpensive.
42425 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
42426 and would like to see what's going on in GLib, a library that's deep
42427 down in its dependency graph. As it turns out, GLib does not have a
42428 @code{debug} output and the backtrace GDB shows is all sadness:
42432 #0 0x00007ffff5f92190 in g_getenv ()
42433 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
42434 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
42435 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
42436 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
42437 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
42438 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
42442 To address that, you install Inkscape linked against a variant GLib that
42443 contains debug info:
42446 guix install inkscape --with-debug-info=glib
42449 This time, debugging will be a whole lot nicer:
42452 $ gdb --args sh -c 'exec inkscape'
42455 Function "g_getenv" not defined.
42456 Make breakpoint pending on future shared library load? (y or [n]) y
42457 Breakpoint 1 (g_getenv) pending.
42459 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
42462 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
42463 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
42464 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
42465 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
42466 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
42472 Note that there can be packages for which @option{--with-debug-info}
42473 will not have the desired effect. @xref{Package Transformation Options,
42474 @option{--with-debug-info}}, for more information.
42476 @node Using TeX and LaTeX
42477 @chapter Using @TeX{} and @LaTeX{}
42479 @cindex @TeX{} packages
42480 @cindex @LaTeX{} packages
42481 Guix provides packages for the @TeX{}, @LaTeX{}, ConTeXt, LuaTeX, and
42482 related typesetting systems, taken from the
42483 @uref{https://www.tug.org/texlive/, @TeX{} Live distribution}. However,
42484 because @TeX{} Live is so huge and because finding your way in this maze
42485 is tricky, we thought that you, dear user, would welcome guidance on how
42486 to deploy the relevant packages so you can compile your @TeX{} and
42487 @LaTeX{} documents.
42489 @TeX{} Live currently comes in two flavors in Guix:
42493 The ``monolithic'' @code{texlive} package: it comes with @emph{every
42494 single @TeX{} Live package} (more than 7,000 of them), but it is huge
42495 (more than 4@tie{}GiB for a single package!).
42498 The ``modular'' @code{texlive-} packages: you install
42499 @code{texlive-base}, which provides core functionality and the main
42500 commands---@command{pdflatex}, @command{dvips}, @command{luatex},
42501 @command{mf}, etc.---together with individual packages that provide just
42502 the features you need---@code{texlive-listings} for the
42503 @code{listings} package, @code{texlive-hyperref} for @code{hyperref},
42504 @code{texlive-beamer} for Beamer, @code{texlive-pgf} for PGF/TikZ,
42508 We recommend using the modular package set because it is much less
42509 resource-hungry. To build your documents, you would use commands such
42513 guix shell texlive-base texlive-wrapfig \
42514 texlive-hyperref texlive-cm-super -- pdflatex doc.tex
42517 You can quickly end up with unreasonably long command lines though. The
42518 solution is to instead write a manifest, for example like this one:
42521 (specifications->manifest
42527 "texlive-microtype"
42528 "texlive-listings" "texlive-hyperref"
42533 ;; Additional fonts.
42534 "texlive-cm-super" "texlive-amsfonts"
42535 "texlive-times" "texlive-helvetic" "texlive-courier"))
42538 You can then pass it to any command with the @option{-m} option:
42541 guix shell -m manifest.scm -- pdflatex doc.tex
42544 @xref{Writing Manifests}, for more on
42545 manifests. In the future, we plan to provide packages for @TeX{} Live
42546 @dfn{collections}---``meta-packages'' such as @code{fontsrecommended},
42547 @code{humanities}, or @code{langarabic} that provide the set of packages
42548 needed in this particular domain. That will allow you to list fewer
42551 The main difficulty here is that using the modular package set forces
42552 you to select precisely the packages that you need. You can use
42553 @command{guix search}, but finding the right package can prove to be
42554 tedious. When a package is missing, @command{pdflatex} and similar
42555 commands fail with an obscure message along the lines of:
42558 doc.tex: File `tikz.sty' not found.
42559 doc.tex:7: Emergency stop.
42563 or, for a missing font:
42566 kpathsea: Running mktexmf phvr7t
42567 ! I can't find file `phvr7t'.
42570 How do you determine what the missing package is? In the first case,
42571 you'll find the answer by running:
42574 $ guix search texlive tikz
42580 In the second case, @command{guix search} turns up nothing. Instead,
42581 you can search the @TeX{} Live package database using the @command{tlmgr}
42585 $ guix shell texlive-base -- tlmgr info phvr7t
42586 tlmgr: cannot find package phvr7t, searching for other matches:
42588 Packages containing `phvr7t' in their title/description:
42590 Packages containing files matching `phvr7t':
42592 texmf-dist/fonts/tfm/adobe/helvetic/phvr7t.tfm
42593 texmf-dist/fonts/tfm/adobe/helvetic/phvr7tn.tfm
42594 texmf-dist/fonts/vf/adobe/helvetic/phvr7t.vf
42595 texmf-dist/fonts/vf/adobe/helvetic/phvr7tn.vf
42597 texmf-dist/tex4ht/ht-fonts/alias/adobe/helvetic/phvr7t.htf
42600 The file is available in the @TeX{} Live @code{helvetic} package, which is
42601 known in Guix as @code{texlive-helvetic}. Quite a ride, but we found
42604 There is one important limitation though: Guix currently provides a
42605 subset of the @TeX{} Live packages. If you stumble upon a missing
42606 package, you can try and import it (@pxref{Invoking guix import}):
42609 guix import texlive @var{package}
42612 Additional options include:
42617 Traverse the dependency graph of the given upstream package recursively
42618 and generate package expressions for all those packages that are not yet
42623 @TeX{} Live packaging is still very much work in progress, but you can
42624 help! @xref{Contributing}, for more information.
42627 @node Security Updates
42628 @chapter Security Updates
42630 @cindex security updates
42631 @cindex security vulnerabilities
42632 Occasionally, important security vulnerabilities are discovered in software
42633 packages and must be patched. Guix developers try hard to keep track of
42634 known vulnerabilities and to apply fixes as soon as possible in the
42635 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
42636 containing only security updates). The @command{guix lint} tool helps
42637 developers find out about vulnerable versions of software packages in the
42642 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
42643 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
42644 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
42648 @xref{Invoking guix lint}, for more information.
42650 Guix follows a functional
42651 package management discipline (@pxref{Introduction}), which implies
42652 that, when a package is changed, @emph{every package that depends on it}
42653 must be rebuilt. This can significantly slow down the deployment of
42654 fixes in core packages such as libc or Bash, since basically the whole
42655 distribution would need to be rebuilt. Using pre-built binaries helps
42656 (@pxref{Substitutes}), but deployment may still take more time than
42660 To address this, Guix implements @dfn{grafts}, a mechanism that allows
42661 for fast deployment of critical updates without the costs associated
42662 with a whole-distribution rebuild. The idea is to rebuild only the
42663 package that needs to be patched, and then to ``graft'' it onto packages
42664 explicitly installed by the user and that were previously referring to
42665 the original package. The cost of grafting is typically very low, and
42666 order of magnitudes lower than a full rebuild of the dependency chain.
42668 @cindex replacements of packages, for grafts
42669 For instance, suppose a security update needs to be applied to Bash.
42670 Guix developers will provide a package definition for the ``fixed''
42671 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
42672 Packages}). Then, the original package definition is augmented with a
42673 @code{replacement} field pointing to the package containing the bug fix:
42680 (replacement bash-fixed)))
42683 From there on, any package depending directly or indirectly on Bash---as
42684 reported by @command{guix gc --requisites} (@pxref{Invoking guix
42685 gc})---that is installed is automatically ``rewritten'' to refer to
42686 @code{bash-fixed} instead of @code{bash}. This grafting process takes
42687 time proportional to the size of the package, usually less than a
42688 minute for an ``average'' package on a recent machine. Grafting is
42689 recursive: when an indirect dependency requires grafting, then grafting
42690 ``propagates'' up to the package that the user is installing.
42692 Currently, the length of the name and version of the graft and that of
42693 the package it replaces (@code{bash-fixed} and @code{bash} in the example
42694 above) must be equal. This restriction mostly comes from the fact that
42695 grafting works by patching files, including binary files, directly.
42696 Other restrictions may apply: for instance, when adding a graft to a
42697 package providing a shared library, the original shared library and its
42698 replacement must have the same @code{SONAME} and be binary-compatible.
42700 The @option{--no-grafts} command-line option allows you to forcefully
42701 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
42705 guix build bash --no-grafts
42709 returns the store file name of the original Bash, whereas:
42716 returns the store file name of the ``fixed'', replacement Bash. This
42717 allows you to distinguish between the two variants of Bash.
42719 To verify which Bash your whole profile refers to, you can run
42720 (@pxref{Invoking guix gc}):
42723 guix gc -R $(readlink -f ~/.guix-profile) | grep bash
42727 @dots{} and compare the store file names that you get with those above.
42728 Likewise for a complete Guix system generation:
42731 guix gc -R $(guix system build my-config.scm) | grep bash
42734 Lastly, to check which Bash running processes are using, you can use the
42735 @command{lsof} command:
42738 lsof | grep /gnu/store/.*bash
42742 @node Bootstrapping
42743 @chapter Bootstrapping
42745 @c Adapted from the ELS 2013 paper.
42747 @cindex bootstrapping
42749 Bootstrapping in our context refers to how the distribution gets built
42750 ``from nothing''. Remember that the build environment of a derivation
42751 contains nothing but its declared inputs (@pxref{Introduction}). So
42752 there's an obvious chicken-and-egg problem: how does the first package
42753 get built? How does the first compiler get compiled?
42755 It is tempting to think of this question as one that only die-hard
42756 hackers may care about. However, while the answer to that question is
42757 technical in nature, its implications are wide-ranging. How the
42758 distribution is bootstrapped defines the extent to which we, as
42759 individuals and as a collective of users and hackers, can trust the
42760 software we run. It is a central concern from the standpoint of
42761 @emph{security} and from a @emph{user freedom} viewpoint.
42763 @cindex bootstrap binaries
42764 The GNU system is primarily made of C code, with libc at its core. The
42765 GNU build system itself assumes the availability of a Bourne shell and
42766 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
42767 `grep'. Furthermore, build programs---programs that run
42768 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
42769 (@pxref{Derivations}). Consequently, to be able to build anything at
42770 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
42771 Binutils, libc, and the other packages mentioned above---the
42772 @dfn{bootstrap binaries}.
42774 These bootstrap binaries are ``taken for granted'', though we can also
42775 re-create them if needed (@pxref{Preparing to Use the Bootstrap
42779 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
42780 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
42783 @node Reduced Binary Seed Bootstrap
42784 @section The Reduced Binary Seed Bootstrap
42786 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
42787 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
42788 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
42789 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
42790 ``taken for granted.''
42792 Taking the bootstrap binaries for granted means that we consider them to
42793 be a correct and trustworthy ``seed'' for building the complete system.
42794 Therein lies a problem: the combined size of these bootstrap binaries is
42795 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
42796 or even inspecting these is next to impossible.
42798 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
42799 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
42800 Source Bootstrap'' and while we are working towards that goal it would
42801 be hyperbole to use that term for what we do now.}.
42803 The Reduced Binary Seed bootstrap removes the most critical tools---from a
42804 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
42805 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
42806 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
42807 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
42809 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
42810 C Library are built from source. From here on the more traditional
42811 bootstrap process resumes. This approach has reduced the bootstrap
42812 binaries in size to about 145MB in Guix v1.1.
42814 The next step that Guix has taken is to replace the shell and all its
42815 utilities with implementations in Guile Scheme, the @emph{Scheme-only
42816 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
42817 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
42818 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
42819 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
42820 removed are now built from source.
42822 Building the GNU System from source is currently only possible by adding
42823 some historical GNU packages as intermediate steps@footnote{Packages
42824 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
42825 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
42826 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
42827 and GNU packages become more bootstrappable again (e.g., new releases of
42828 GNU Sed will also ship as gzipped tarballs again, as alternative to the
42829 hard to bootstrap @code{xz}-compression), this set of added packages can
42830 hopefully be reduced again.
42832 The graph below shows the resulting dependency graph for
42833 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
42834 traditional bootstrap of the rest of the Guix System.
42836 @c ./pre-inst-env guix graph -e '(@@ (gnu packages commencement) gcc-core-mesboot0)' | sed -re 's,((bootstrap-mescc-tools|bootstrap-mes|guile-bootstrap).*shape =) box,\1 ellipse,' > doc/images/gcc-core-mesboot0-graph.dot
42837 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
42839 The only significant binary bootstrap seeds that remain@footnote{
42840 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
42841 together with @code{mes}.} are a Scheme interpreter and a Scheme
42842 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
42843 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
42844 to get Guile running.}.
42846 This further reduction has brought down the size of the binary seed to
42847 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
42849 Work is ongoing to remove all binary blobs from our free software
42850 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
42851 is work to bring these bootstraps to the @code{arm-linux} and
42852 @code{aarch64-linux} architectures and to the Hurd.
42854 If you are interested, join us on @samp{#bootstrappable} on the Freenode
42855 IRC network or discuss on @email{bug-mes@@gnu.org} or
42856 @email{gash-devel@@nongnu.org}.
42858 @node Preparing to Use the Bootstrap Binaries
42859 @section Preparing to Use the Bootstrap Binaries
42861 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
42862 @c large image, it's hard to scroll. Oh well.
42863 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
42865 The figure above shows the very beginning of the dependency graph of the
42866 distribution, corresponding to the package definitions of the @code{(gnu
42867 packages bootstrap)} module. A similar figure can be generated with
42868 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
42871 guix graph -t derivation \
42872 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
42873 | dot -Tps > gcc.ps
42876 or, for the further Reduced Binary Seed bootstrap
42879 guix graph -t derivation \
42880 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
42881 | dot -Tps > mes.ps
42884 At this level of detail, things are
42885 slightly complex. First, Guile itself consists of an ELF executable,
42886 along with many source and compiled Scheme files that are dynamically
42887 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
42888 tarball shown in this graph. This tarball is part of Guix's ``source''
42889 distribution, and gets inserted into the store with @code{add-to-store}
42890 (@pxref{The Store}).
42892 But how do we write a derivation that unpacks this tarball and adds it
42893 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
42894 derivation---the first one that gets built---uses @code{bash} as its
42895 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
42896 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
42897 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
42898 the Guix source distribution, whose sole purpose is to allow the Guile
42899 tarball to be unpacked.
42901 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
42902 Guile that can be used to run subsequent build programs. Its first task
42903 is to download tarballs containing the other pre-built binaries---this
42904 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
42905 @code{ftp-client.scm} are used for this purpose. The
42906 @code{module-import.drv} derivations import those modules in a directory
42907 in the store, using the original layout. The
42908 @code{module-import-compiled.drv} derivations compile those modules, and
42909 write them in an output directory with the right layout. This
42910 corresponds to the @code{#:modules} argument of
42911 @code{build-expression->derivation} (@pxref{Derivations}).
42913 Finally, the various tarballs are unpacked by the derivations
42914 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
42915 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
42916 point we have a working C tool chain.
42918 @unnumberedsec Building the Build Tools
42920 Bootstrapping is complete when we have a full tool chain that does not
42921 depend on the pre-built bootstrap tools discussed above. This
42922 no-dependency requirement is verified by checking whether the files of
42923 the final tool chain contain references to the @file{/gnu/store}
42924 directories of the bootstrap inputs. The process that leads to this
42925 ``final'' tool chain is described by the package definitions found in
42926 the @code{(gnu packages commencement)} module.
42928 The @command{guix graph} command allows us to ``zoom out'' compared to
42929 the graph above, by looking at the level of package objects instead of
42930 individual derivations---remember that a package may translate to
42931 several derivations, typically one derivation to download its source,
42932 one to build the Guile modules it needs, and one to actually build the
42933 package from source. The command:
42936 guix graph -t bag \
42937 -e '(@@@@ (gnu packages commencement)
42938 glibc-final-with-bootstrap-bash)' | xdot -
42942 displays the dependency graph leading to the ``final'' C
42943 library@footnote{You may notice the @code{glibc-intermediate} label,
42944 suggesting that it is not @emph{quite} final, but as a good
42945 approximation, we will consider it final.}, depicted below.
42947 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
42949 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
42950 The first tool that gets built with the bootstrap binaries is
42951 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
42952 for all the following packages. From there Findutils and Diffutils get
42955 Then come the first-stage Binutils and GCC, built as pseudo cross
42956 tools---i.e., with @option{--target} equal to @option{--host}. They are
42957 used to build libc. Thanks to this cross-build trick, this libc is
42958 guaranteed not to hold any reference to the initial tool chain.
42960 From there the final Binutils and GCC (not shown above) are built. GCC
42961 uses @command{ld} from the final Binutils, and links programs against
42962 the just-built libc. This tool chain is used to build the other
42963 packages used by Guix and by the GNU Build System: Guile, Bash,
42966 And voilà! At this point we have the complete set of build tools that
42967 the GNU Build System expects. These are in the @code{%final-inputs}
42968 variable of the @code{(gnu packages commencement)} module, and are
42969 implicitly used by any package that uses @code{gnu-build-system}
42970 (@pxref{Build Systems, @code{gnu-build-system}}).
42973 @unnumberedsec Building the Bootstrap Binaries
42975 @cindex bootstrap binaries
42976 Because the final tool chain does not depend on the bootstrap binaries,
42977 those rarely need to be updated. Nevertheless, it is useful to have an
42978 automated way to produce them, should an update occur, and this is what
42979 the @code{(gnu packages make-bootstrap)} module provides.
42981 The following command builds the tarballs containing the bootstrap binaries
42982 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
42983 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
42984 and Guile, and a tarball containing a mixture of Coreutils and other basic
42985 command-line tools):
42988 guix build bootstrap-tarballs
42991 The generated tarballs are those that should be referred to in the
42992 @code{(gnu packages bootstrap)} module mentioned at the beginning of
42995 Still here? Then perhaps by now you've started to wonder: when do we
42996 reach a fixed point? That is an interesting question! The answer is
42997 unknown, but if you would like to investigate further (and have
42998 significant computational and storage resources to do so), then let us
43001 @unnumberedsec Reducing the Set of Bootstrap Binaries
43003 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
43004 binary code! Why is that a problem? It's a problem because these big chunks
43005 of binary code are practically non-auditable, which makes it hard to establish
43006 what source code produced them. Every unauditable binary also leaves us
43007 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
43008 paper @emph{Reflections on Trusting Trust}.
43010 This is mitigated by the fact that our bootstrap binaries were generated
43011 from an earlier Guix revision. Nevertheless it lacks the level of
43012 transparency that we get in the rest of the package dependency graph,
43013 where Guix always gives us a source-to-binary mapping. Thus, our goal
43014 is to reduce the set of bootstrap binaries to the bare minimum.
43016 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
43017 on-going projects to do that. One of these is about replacing the
43018 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
43019 of increasing complexity, which could be built from source starting from
43020 a simple and auditable assembler.
43022 Our first major achievement is the replacement of of GCC, the GNU C Library
43023 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
43024 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
43025 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
43026 bootstrapped yet and thus we inject them as binary seeds. We call this the
43027 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
43028 binaries! Also, it has eliminated the C compiler binary; i686-linux and
43029 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
43031 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
43032 also looking at any other bootstrap binaries. Your help is welcome!
43035 @chapter Porting to a New Platform
43037 As discussed above, the GNU distribution is self-contained, and
43038 self-containment is achieved by relying on pre-built ``bootstrap
43039 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
43040 operating system kernel, CPU architecture, and application binary
43041 interface (ABI). Thus, to port the distribution to a platform that is
43042 not yet supported, one must build those bootstrap binaries, and update
43043 the @code{(gnu packages bootstrap)} module to use them on that platform.
43045 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
43046 When everything goes well, and assuming the GNU tool chain supports the
43047 target platform, this can be as simple as running a command like this
43051 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
43054 For this to work, it is first required to register a new platform as
43055 defined in the @code{(guix platform)} module. A platform is making the
43056 connection between a GNU triplet (@pxref{Specifying Target Triplets, GNU
43057 configuration triplets,, autoconf, Autoconf}), the equivalent
43058 @var{system} in Nix notation, the name of the
43059 @var{glibc-dynamic-linker}, and the corresponding Linux architecture
43060 name if applicable (@pxref{Platforms}).
43062 Once the bootstrap tarball are built, the @code{(gnu packages
43063 bootstrap)} module needs to be updated to refer to these binaries on the
43064 target platform. That is, the hashes and URLs of the bootstrap tarballs
43065 for the new platform must be added alongside those of the currently
43066 supported platforms. The bootstrap Guile tarball is treated specially:
43067 it is expected to be available locally, and @file{gnu/local.mk} has
43068 rules to download it for the supported architectures; a rule for the new
43069 platform must be added as well.
43071 In practice, there may be some complications. First, it may be that the
43072 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
43073 above) is not recognized by all the GNU tools. Typically, glibc
43074 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
43075 configure flag (see @code{gcc.scm} for examples of how to handle this).
43076 Second, some of the required packages could fail to build for that
43077 platform. Lastly, the generated binaries could be broken for some
43080 @c *********************************************************************
43081 @include contributing.texi
43083 @c *********************************************************************
43084 @node Acknowledgments
43085 @chapter Acknowledgments
43087 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
43088 which was designed and
43089 implemented by Eelco Dolstra, with contributions from other people (see
43090 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
43091 management, and promoted unprecedented features, such as transactional
43092 package upgrades and rollbacks, per-user profiles, and referentially
43093 transparent build processes. Without this work, Guix would not exist.
43095 The Nix-based software distributions, Nixpkgs and NixOS, have also been
43096 an inspiration for Guix.
43098 GNU@tie{}Guix itself is a collective work with contributions from a
43099 number of people. See the @file{AUTHORS} file in Guix for more
43100 information on these fine people. The @file{THANKS} file lists people
43101 who have helped by reporting bugs, taking care of the infrastructure,
43102 providing artwork and themes, making suggestions, and more---thank you!
43105 @c *********************************************************************
43106 @node GNU Free Documentation License
43107 @appendix GNU Free Documentation License
43108 @cindex license, GNU Free Documentation License
43109 @include fdl-1.3.texi
43111 @c *********************************************************************
43112 @node Concept Index
43113 @unnumbered Concept Index
43116 @node Programming Index
43117 @unnumbered Programming Index
43118 @syncodeindex tp fn
43119 @syncodeindex vr fn
43124 @c Local Variables:
43125 @c ispell-local-dictionary: "american";