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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 @node Scheduled Job Execution
18685 @subsection Scheduled Job Execution
18689 @cindex scheduling jobs
18690 The @code{(gnu services mcron)} module provides an interface to
18691 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
18692 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
18693 Unix @command{cron} daemon; the main difference is that it is
18694 implemented in Guile Scheme, which provides a lot of flexibility when
18695 specifying the scheduling of jobs and their actions.
18697 The example below defines an operating system that runs the
18698 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
18699 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
18700 well as the @command{mkid} command on behalf of an unprivileged user
18701 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
18702 gexps to introduce job definitions that are passed to mcron
18703 (@pxref{G-Expressions}).
18706 (use-modules (guix) (gnu) (gnu services mcron))
18707 (use-package-modules base idutils)
18709 (define updatedb-job
18710 ;; Run 'updatedb' at 3AM every day. Here we write the
18711 ;; job's action as a Scheme procedure.
18712 #~(job '(next-hour '(3))
18714 (execl (string-append #$findutils "/bin/updatedb")
18716 "--prunepaths=/tmp /var/tmp /gnu/store"))
18719 (define garbage-collector-job
18720 ;; Collect garbage 5 minutes after midnight every day.
18721 ;; The job's action is a shell command.
18722 #~(job "5 0 * * *" ;Vixie cron syntax
18725 (define idutils-job
18726 ;; Update the index database as user "charlie" at 12:15PM
18727 ;; and 19:15PM. This runs from the user's home directory.
18728 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
18729 (string-append #$idutils "/bin/mkid src")
18735 ;; %BASE-SERVICES already includes an instance of
18736 ;; 'mcron-service-type', which we extend with additional
18737 ;; jobs using 'simple-service'.
18738 (services (cons (simple-service 'my-cron-jobs
18740 (list garbage-collector-job
18747 When providing the action of a job specification as a procedure, you
18748 should provide an explicit name for the job via the optional 3rd
18749 argument as done in the @code{updatedb-job} example above. Otherwise,
18750 the job would appear as ``Lambda function'' in the output of
18751 @command{herd schedule mcron}, which is not nearly descriptive enough!
18754 For more complex jobs defined in Scheme where you need control over the top
18755 level, for instance to introduce a @code{use-modules} form, you can move your
18756 code to a separate program using the @code{program-file} procedure of the
18757 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
18761 (define %battery-alert-job
18762 ;; Beep when the battery percentage falls below %MIN-LEVEL.
18764 '(next-minute (range 0 60 1))
18766 "battery-alert.scm"
18767 (with-imported-modules (source-module-closure
18768 '((guix build utils)))
18770 (use-modules (guix build utils)
18773 (ice-9 textual-ports)
18776 (define %min-level 20)
18778 (setenv "LC_ALL" "C") ;ensure English output
18779 (and-let* ((input-pipe (open-pipe*
18781 #$(file-append acpi "/bin/acpi")))
18782 (output (get-string-all input-pipe))
18783 (m (string-match "Discharging, ([0-9]+)%" output))
18784 (level (string->number (match:substring m 1)))
18785 ((< level %min-level)))
18786 (format #t "warning: Battery level is low (~a%)~%" level)
18787 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
18790 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
18791 for more information on mcron job specifications. Below is the
18792 reference of the mcron service.
18794 On a running system, you can use the @code{schedule} action of the service to
18795 visualize the mcron jobs that will be executed next:
18798 # herd schedule mcron
18802 The example above lists the next five tasks that will be executed, but you can
18803 also specify the number of tasks to display:
18806 # herd schedule mcron 10
18809 @defvr {Scheme Variable} mcron-service-type
18810 This is the type of the @code{mcron} service, whose value is an
18811 @code{mcron-configuration} object.
18813 This service type can be the target of a service extension that provides
18814 additional job specifications (@pxref{Service Composition}). In other
18815 words, it is possible to define services that provide additional mcron
18819 @deftp {Data Type} mcron-configuration
18820 Data type representing the configuration of mcron.
18823 @item @code{mcron} (default: @var{mcron})
18824 The mcron package to use.
18827 This is a list of gexps (@pxref{G-Expressions}), where each gexp
18828 corresponds to an mcron job specification (@pxref{Syntax, mcron job
18829 specifications,, mcron, GNU@tie{}mcron}).
18835 @subsection Log Rotation
18838 @cindex log rotation
18840 Log files such as those found in @file{/var/log} tend to grow endlessly,
18841 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
18842 their contents in separate files, possibly compressed. The @code{(gnu
18843 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
18844 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
18846 This service is part of @code{%base-services}, and thus enabled by
18847 default, with the default settings, for commonly encountered log files.
18848 The example below shows how to extend it with an additional
18849 @dfn{rotation}, should you need to do that (usually, services that
18850 produce log files already take care of that):
18853 (use-modules (guix) (gnu))
18854 (use-service-modules admin)
18856 (define my-log-files
18857 ;; Log files that I want to rotate.
18858 '("/var/log/something.log" "/var/log/another.log"))
18862 (services (cons (simple-service 'rotate-my-stuff
18863 rottlog-service-type
18864 (list (log-rotation
18866 (files my-log-files))))
18870 @defvr {Scheme Variable} rottlog-service-type
18871 This is the type of the Rottlog service, whose value is a
18872 @code{rottlog-configuration} object.
18874 Other services can extend this one with new @code{log-rotation} objects
18875 (see below), thereby augmenting the set of files to be rotated.
18877 This service type can define mcron jobs (@pxref{Scheduled Job
18878 Execution}) to run the rottlog service.
18881 @deftp {Data Type} rottlog-configuration
18882 Data type representing the configuration of rottlog.
18885 @item @code{rottlog} (default: @code{rottlog})
18886 The Rottlog package to use.
18888 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
18889 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
18890 rottlog, GNU Rot[t]log Manual}).
18892 @item @code{rotations} (default: @code{%default-rotations})
18893 A list of @code{log-rotation} objects as defined below.
18896 This is a list of gexps where each gexp corresponds to an mcron job
18897 specification (@pxref{Scheduled Job Execution}).
18901 @deftp {Data Type} log-rotation
18902 Data type representing the rotation of a group of log files.
18904 Taking an example from the Rottlog manual (@pxref{Period Related File
18905 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
18911 (files '("/var/log/apache/*"))
18912 (options '("storedir apache-archives"
18918 The list of fields is as follows:
18921 @item @code{frequency} (default: @code{'weekly})
18922 The log rotation frequency, a symbol.
18925 The list of files or file glob patterns to rotate.
18927 @vindex %default-log-rotation-options
18928 @item @code{options} (default: @code{%default-log-rotation-options})
18929 The list of rottlog options for this rotation (@pxref{Configuration
18930 parameters,,, rottlog, GNU Rot[t]log Manual}).
18932 @item @code{post-rotate} (default: @code{#f})
18933 Either @code{#f} or a gexp to execute once the rotation has completed.
18937 @defvr {Scheme Variable} %default-rotations
18938 Specifies weekly rotation of @code{%rotated-files} and of
18939 @file{/var/log/guix-daemon.log}.
18942 @defvr {Scheme Variable} %rotated-files
18943 The list of syslog-controlled files to be rotated. By default it is:
18944 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
18945 "/var/log/maillog")}.
18948 Some log files just need to be deleted periodically once they are old,
18949 without any other criterion and without any archival step. This is the
18950 case of build logs stored by @command{guix-daemon} under
18951 @file{/var/log/guix/drvs} (@pxref{Invoking guix-daemon}). The
18952 @code{log-cleanup} service addresses this use case. For example,
18953 @code{%base-services} (@pxref{Base Services}) includes the following:
18956 ;; Periodically delete old build logs.
18957 (service log-cleanup-service-type
18958 (log-cleanup-configuration
18959 (directory "/var/log/guix/drvs")))
18962 That ensures build logs do not accumulate endlessly.
18964 @defvr {Scheme Variable} log-cleanup-service-type
18965 This is the type of the service to delete old logs. Its value must be a
18966 @code{log-cleanup-configuration} record as described below.
18969 @deftp {Data Type} log-cleanup-configuration
18970 Data type representing the log cleanup configuration
18973 @item @code{directory}
18974 Name of the directory containing log files.
18976 @item @code{expiry} (default: @code{(* 6 30 24 3600)})
18977 Age in seconds after which a file is subject to deletion (six months by
18980 @item @code{schedule} (default: @code{"30 12 01,08,15,22 * *"})
18981 String or gexp denoting the corresponding mcron job schedule
18982 (@pxref{Scheduled Job Execution}).
18986 @cindex logging, anonymization
18987 @subheading Anonip Service
18989 Anonip is a privacy filter that removes IP address from web server logs.
18990 This service creates a FIFO and filters any written lines with anonip
18991 before writing the filtered log to a target file.
18993 The following example sets up the FIFO
18994 @file{/var/run/anonip/https.access.log} and writes the filtered log file
18995 @file{/var/log/anonip/https.access.log}.
18998 (service anonip-service-type
18999 (anonip-configuration
19000 (input "/var/run/anonip/https.access.log")
19001 (output "/var/log/anonip/https.access.log")))
19004 Configure your web server to write its logs to the FIFO at
19005 @file{/var/run/anonip/https.access.log} and collect the anonymized log
19006 file at @file{/var/web-logs/https.access.log}.
19008 @deftp {Data Type} anonip-configuration
19009 This data type represents the configuration of anonip.
19010 It has the following parameters:
19013 @item @code{anonip} (default: @code{anonip})
19014 The anonip package to use.
19017 The file name of the input log file to process. The service creates a
19018 FIFO of this name. The web server should write its logs to this FIFO.
19020 @item @code{output}
19021 The file name of the processed log file.
19024 The following optional settings may be provided:
19027 @item @code{skip-private?}
19028 When @code{#true} do not mask addresses in private ranges.
19030 @item @code{column}
19031 A 1-based indexed column number. Assume IP address is in the specified
19032 column (default is 1).
19034 @item @code{replacement}
19035 Replacement string in case address parsing fails, e.g. @code{"0.0.0.0"}.
19037 @item @code{ipv4mask}
19038 Number of bits to mask in IPv4 addresses.
19040 @item @code{ipv6mask}
19041 Number of bits to mask in IPv6 addresses.
19043 @item @code{increment}
19044 Increment the IP address by the given number. By default this is zero.
19046 @item @code{delimiter}
19047 Log delimiter string.
19050 Regular expression for detecting IP addresses. Use this instead of @code{column}.
19055 @node Networking Setup
19056 @subsection Networking Setup
19058 The @code{(gnu services networking)} module provides services to
19059 configure network interfaces and set up networking on your machine.
19060 Those services provide different ways for you to set up your machine: by
19061 declaring a static network configuration, by running a Dynamic Host
19062 Configuration Protocol (DHCP) client, or by running daemons such as
19063 NetworkManager and Connman that automate the whole process,
19064 automatically adapt to connectivity changes, and provide a high-level
19067 On a laptop, NetworkManager and Connman are by far the most convenient
19068 options, which is why the default desktop services include
19069 NetworkManager (@pxref{Desktop Services, @code{%desktop-services}}).
19070 For a server, or for a virtual machine or a container, static network
19071 configuration or a simple DHCP client are often more appropriate.
19073 This section describes the various network setup services available,
19074 starting with static network configuration.
19076 @defvr {Scheme Variable} static-networking-service-type
19077 This is the type for statically-configured network interfaces. Its
19078 value must be a list of @code{static-networking} records. Each of them
19079 declares a set of @dfn{addresses}, @dfn{routes}, and @dfn{links}, as
19082 @cindex network interface controller (NIC)
19083 @cindex NIC, networking interface controller
19084 Here is the simplest configuration, with only one network interface
19085 controller (NIC) and only IPv4 connectivity:
19088 ;; Static networking for one NIC, IPv4-only.
19089 (service static-networking-service-type
19090 (list (static-networking
19092 (list (network-address
19094 (value "10.0.2.15/24"))))
19096 (list (network-route
19097 (destination "default")
19098 (gateway "10.0.2.2"))))
19099 (name-servers '("10.0.2.3")))))
19102 The snippet above can be added to the @code{services} field of your
19103 operating system configuration (@pxref{Using the Configuration System}).
19104 It will configure your machine to have 10.0.2.15 as its IP address, with
19105 a 24-bit netmask for the local network---meaning that any 10.0.2.@var{x}
19106 address is on the local area network (LAN). Traffic to addresses
19107 outside the local network is routed @i{via} 10.0.2.2. Host names are
19108 resolved by sending domain name system (DNS) queries to 10.0.2.3.
19111 @deftp {Data Type} static-networking
19112 This is the data type representing a static network configuration.
19114 As an example, here is how you would declare the configuration of a
19115 machine with a single network interface controller (NIC) available as
19116 @code{eno1}, and with one IPv4 and one IPv6 address:
19119 ;; Network configuration for one NIC, IPv4 + IPv6.
19121 (addresses (list (network-address
19123 (value "10.0.2.15/24"))
19126 (value "2001:123:4567:101::1/64"))))
19127 (routes (list (network-route
19128 (destination "default")
19129 (gateway "10.0.2.2"))
19131 (destination "default")
19132 (gateway "2020:321:4567:42::1"))))
19133 (name-servers '("10.0.2.3")))
19136 If you are familiar with the @command{ip} command of the
19137 @uref{https://wiki.linuxfoundation.org/networking/iproute2,
19138 @code{iproute2} package} found on Linux-based systems, the declaration
19139 above is equivalent to typing:
19142 ip address add 10.0.2.15/24 dev eno1
19143 ip address add 2001:123:4567:101::1/64 dev eno1
19144 ip route add default via inet 10.0.2.2
19145 ip route add default via inet6 2020:321:4567:42::1
19148 Run @command{man 8 ip} for more info. Venerable GNU/Linux users will
19149 certainly know how to do it with @command{ifconfig} and @command{route},
19150 but we'll spare you that.
19152 The available fields of this data type are as follows:
19155 @item @code{addresses}
19156 @itemx @code{links} (default: @code{'()})
19157 @itemx @code{routes} (default: @code{'()})
19158 The list of @code{network-address}, @code{network-link}, and
19159 @code{network-route} records for this network (see below).
19161 @item @code{name-servers} (default: @code{'()})
19162 The list of IP addresses (strings) of domain name servers. These IP
19163 addresses go to @file{/etc/resolv.conf}.
19165 @item @code{provision} (default: @code{'(networking)})
19166 If true, this should be a list of symbols for the Shepherd service
19167 corresponding to this network configuration.
19169 @item @code{requirement} (default @code{'()})
19170 The list of Shepherd services depended on.
19174 @deftp {Data Type} network-address
19175 This is the data type representing the IP address of a network
19180 The name of the network interface for this address---e.g.,
19184 The actual IP address and network mask, in
19185 @uref{https://en.wikipedia.org/wiki/CIDR#CIDR_notation, @acronym{CIDR,
19186 Classless Inter-Domain Routing} notation}, as a string.
19188 For example, @code{"10.0.2.15/24"} denotes IPv4 address 10.0.2.15 on a
19189 24-bit sub-network---all 10.0.2.@var{x} addresses are on the same local
19193 Whether @code{value} denotes an IPv6 address. By default this is
19194 automatically determined.
19198 @deftp {Data Type} network-route
19199 This is the data type representing a network route.
19202 @item @code{destination}
19203 The route destination (a string), either an IP address and network mask
19204 or @code{"default"} to denote the default route.
19206 @item @code{source} (default: @code{#f})
19209 @item @code{device} (default: @code{#f})
19210 The device used for this route---e.g., @code{"eno2"}.
19212 @item @code{ipv6?} (default: auto)
19213 Whether this is an IPv6 route. By default this is automatically
19214 determined based on @code{destination} or @code{gateway}.
19216 @item @code{gateway} (default: @code{#f})
19217 IP address (a string) through which traffic is routed.
19221 @deftp {Data Type} network-link
19222 Data type for a network link (@pxref{Link,,, guile-netlink,
19223 Guile-Netlink Manual}).
19227 The name of the link---e.g., @code{"v0p0"}.
19230 A symbol denoting the type of the link---e.g., @code{'veth}.
19233 List of arguments for this type of link.
19237 @cindex loopback device
19238 @defvr {Scheme Variable} %loopback-static-networking
19239 This is the @code{static-networking} record representing the ``loopback
19240 device'', @code{lo}, for IP addresses 127.0.0.1 and ::1, and providing
19241 the @code{loopback} Shepherd service.
19244 @cindex networking, with QEMU
19245 @cindex QEMU, networking
19246 @defvr {Scheme Variable} %qemu-static-networking
19247 This is the @code{static-networking} record representing network setup
19248 when using QEMU's user-mode network stack on @code{eth0} (@pxref{Using
19249 the user mode network stack,,, QEMU, QEMU Documentation}).
19252 @cindex DHCP, networking service
19253 @defvr {Scheme Variable} dhcp-client-service-type
19254 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
19255 Protocol (DHCP) client.
19258 @deftp {Data Type} dhcp-client-configuration
19259 Data type representing the configuration of the DHCP client service.
19262 @item @code{package} (default: @code{isc-dhcp})
19263 DHCP client package to use.
19265 @item @code{interfaces} (default: @code{'all})
19266 Either @code{'all} or the list of interface names that the DHCP client
19267 should listen on---e.g., @code{'("eno1")}.
19269 When set to @code{'all}, the DHCP client listens on all the available
19270 non-loopback interfaces that can be activated. Otherwise the DHCP
19271 client listens only on the specified interfaces.
19275 @cindex NetworkManager
19277 @defvr {Scheme Variable} network-manager-service-type
19278 This is the service type for the
19279 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
19280 service. The value for this service type is a
19281 @code{network-manager-configuration} record.
19283 This service is part of @code{%desktop-services} (@pxref{Desktop
19287 @deftp {Data Type} network-manager-configuration
19288 Data type representing the configuration of NetworkManager.
19291 @item @code{network-manager} (default: @code{network-manager})
19292 The NetworkManager package to use.
19294 @item @code{dns} (default: @code{"default"})
19295 Processing mode for DNS, which affects how NetworkManager uses the
19296 @code{resolv.conf} configuration file.
19300 NetworkManager will update @code{resolv.conf} to reflect the nameservers
19301 provided by currently active connections.
19304 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
19305 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
19306 then update @code{resolv.conf} to point to the local nameserver.
19308 With this setting, you can share your network connection. For example when
19309 you want to share your network connection to another laptop @i{via} an
19310 Ethernet cable, you can open @command{nm-connection-editor} and configure the
19311 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
19312 and reestablish the connection (or reboot).
19314 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
19315 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
19316 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
19317 browser on your host system, or connect to the VM @i{via} SSH
19318 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
19319 host-to-guest connection, run this command once:
19322 nmcli connection add type tun \
19323 connection.interface-name tap0 \
19324 tun.mode tap tun.owner $(id -u) \
19325 ipv4.method shared \
19326 ipv4.addresses 172.28.112.1/24
19329 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
19330 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
19331 @command{qemu-system-...}.
19334 NetworkManager will not modify @code{resolv.conf}.
19337 @item @code{vpn-plugins} (default: @code{'()})
19338 This is the list of available plugins for virtual private networks
19339 (VPNs). An example of this is the @code{network-manager-openvpn}
19340 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
19346 @deffn {Scheme Variable} connman-service-type
19347 This is the service type to run @url{https://01.org/connman,Connman},
19348 a network connection manager.
19350 Its value must be an
19351 @code{connman-configuration} record as in this example:
19354 (service connman-service-type
19355 (connman-configuration
19356 (disable-vpn? #t)))
19359 See below for details about @code{connman-configuration}.
19362 @deftp {Data Type} connman-configuration
19363 Data Type representing the configuration of connman.
19366 @item @code{connman} (default: @var{connman})
19367 The connman package to use.
19369 @item @code{disable-vpn?} (default: @code{#f})
19370 When true, disable connman's vpn plugin.
19374 @cindex WPA Supplicant
19375 @defvr {Scheme Variable} wpa-supplicant-service-type
19376 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
19377 supplicant}, an authentication daemon required to authenticate against
19378 encrypted WiFi or ethernet networks.
19381 @deftp {Data Type} wpa-supplicant-configuration
19382 Data type representing the configuration of WPA Supplicant.
19384 It takes the following parameters:
19387 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
19388 The WPA Supplicant package to use.
19390 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
19391 List of services that should be started before WPA Supplicant starts.
19393 @item @code{dbus?} (default: @code{#t})
19394 Whether to listen for requests on D-Bus.
19396 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
19397 Where to store the PID file.
19399 @item @code{interface} (default: @code{#f})
19400 If this is set, it must specify the name of a network interface that
19401 WPA supplicant will control.
19403 @item @code{config-file} (default: @code{#f})
19404 Optional configuration file to use.
19406 @item @code{extra-options} (default: @code{'()})
19407 List of additional command-line arguments to pass to the daemon.
19411 @cindex ModemManager
19412 Some networking devices such as modems require special care, and this is
19413 what the services below focus on.
19415 @defvr {Scheme Variable} modem-manager-service-type
19416 This is the service type for the
19417 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
19418 service. The value for this service type is a
19419 @code{modem-manager-configuration} record.
19421 This service is part of @code{%desktop-services} (@pxref{Desktop
19425 @deftp {Data Type} modem-manager-configuration
19426 Data type representing the configuration of ModemManager.
19429 @item @code{modem-manager} (default: @code{modem-manager})
19430 The ModemManager package to use.
19435 @cindex USB_ModeSwitch
19436 @cindex Modeswitching
19438 @defvr {Scheme Variable} usb-modeswitch-service-type
19439 This is the service type for the
19440 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
19441 service. The value for this service type is
19442 a @code{usb-modeswitch-configuration} record.
19444 When plugged in, some USB modems (and other USB devices) initially present
19445 themselves as a read-only storage medium and not as a modem. They need to be
19446 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
19447 installs udev rules to automatically modeswitch these devices when they are
19450 This service is part of @code{%desktop-services} (@pxref{Desktop
19454 @deftp {Data Type} usb-modeswitch-configuration
19455 Data type representing the configuration of USB_ModeSwitch.
19458 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
19459 The USB_ModeSwitch package providing the binaries for modeswitching.
19461 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
19462 The package providing the device data and udev rules file used by
19465 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
19466 Which config file to use for the USB_ModeSwitch dispatcher. By default the
19467 config file shipped with USB_ModeSwitch is used which disables logging to
19468 @file{/var/log} among other default settings. If set to @code{#f}, no config
19475 @node Networking Services
19476 @subsection Networking Services
19478 The @code{(gnu services networking)} module discussed in the previous
19479 section provides services for more advanced setups: providing a DHCP
19480 service for others to use, filtering packets with iptables or nftables,
19481 running a WiFi access point with @command{hostapd}, running the
19482 @command{inetd} ``superdaemon'', and more. This section describes
19485 @deffn {Scheme Procedure} dhcpd-service-type
19486 This type defines a service that runs a DHCP daemon. To create a
19487 service of this type, you must supply a @code{<dhcpd-configuration>}.
19491 (service dhcpd-service-type
19492 (dhcpd-configuration
19493 (config-file (local-file "my-dhcpd.conf"))
19494 (interfaces '("enp0s25"))))
19498 @deftp {Data Type} dhcpd-configuration
19500 @item @code{package} (default: @code{isc-dhcp})
19501 The package that provides the DHCP daemon. This package is expected to
19502 provide the daemon at @file{sbin/dhcpd} relative to its output
19503 directory. The default package is the
19504 @uref{https://www.isc.org/dhcp/, ISC's DHCP server}.
19505 @item @code{config-file} (default: @code{#f})
19506 The configuration file to use. This is required. It will be passed to
19507 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
19508 object (@pxref{G-Expressions, file-like objects}). See @code{man
19509 dhcpd.conf} for details on the configuration file syntax.
19510 @item @code{version} (default: @code{"4"})
19511 The DHCP version to use. The ISC DHCP server supports the values ``4'',
19512 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
19513 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
19515 @item @code{run-directory} (default: @code{"/run/dhcpd"})
19516 The run directory to use. At service activation time, this directory
19517 will be created if it does not exist.
19518 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
19519 The PID file to use. This corresponds to the @code{-pf} option of
19520 @code{dhcpd}. See @code{man dhcpd} for details.
19521 @item @code{interfaces} (default: @code{'()})
19522 The names of the network interfaces on which dhcpd should listen for
19523 broadcasts. If this list is not empty, then its elements (which must be
19524 strings) will be appended to the @code{dhcpd} invocation when starting
19525 the daemon. It may not be necessary to explicitly specify any
19526 interfaces here; see @code{man dhcpd} for details.
19530 @cindex hostapd service, for Wi-Fi access points
19531 @cindex Wi-Fi access points, hostapd service
19532 @defvr {Scheme Variable} hostapd-service-type
19533 This is the service type to run the @uref{https://w1.fi/hostapd/,
19534 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
19535 authentication servers. Its associated value must be a
19536 @code{hostapd-configuration} as shown below:
19539 ;; Use wlan1 to run the access point for "My Network".
19540 (service hostapd-service-type
19541 (hostapd-configuration
19542 (interface "wlan1")
19543 (ssid "My Network")
19548 @deftp {Data Type} hostapd-configuration
19549 This data type represents the configuration of the hostapd service, with
19550 the following fields:
19553 @item @code{package} (default: @code{hostapd})
19554 The hostapd package to use.
19556 @item @code{interface} (default: @code{"wlan0"})
19557 The network interface to run the WiFi access point.
19560 The SSID (@dfn{service set identifier}), a string that identifies this
19563 @item @code{broadcast-ssid?} (default: @code{#t})
19564 Whether to broadcast this SSID.
19566 @item @code{channel} (default: @code{1})
19567 The WiFi channel to use.
19569 @item @code{driver} (default: @code{"nl80211"})
19570 The driver interface type. @code{"nl80211"} is used with all Linux
19571 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
19572 RADIUS server that does # not control any wireless/wired driver.
19574 @item @code{extra-settings} (default: @code{""})
19575 Extra settings to append as-is to the hostapd configuration file. See
19576 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
19577 configuration file reference.
19581 @defvr {Scheme Variable} simulated-wifi-service-type
19582 This is the type of a service to simulate WiFi networking, which can be
19583 useful in virtual machines for testing purposes. The service loads the
19585 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
19586 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
19587 network that can be seen on @code{wlan0}, by default.
19589 The service's value is a @code{hostapd-configuration} record.
19594 @defvr {Scheme Variable} iptables-service-type
19595 This is the service type to set up an iptables configuration. iptables is a
19596 packet filtering framework supported by the Linux kernel. This service
19597 supports configuring iptables for both IPv4 and IPv6. A simple example
19598 configuration rejecting all incoming connections except those to the ssh port
19602 (service iptables-service-type
19603 (iptables-configuration
19604 (ipv4-rules (plain-file "iptables.rules" "*filter
19608 -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
19609 -A INPUT -p tcp --dport 22 -j ACCEPT
19610 -A INPUT -j REJECT --reject-with icmp-port-unreachable
19613 (ipv6-rules (plain-file "ip6tables.rules" "*filter
19617 -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
19618 -A INPUT -p tcp --dport 22 -j ACCEPT
19619 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
19625 @deftp {Data Type} iptables-configuration
19626 The data type representing the configuration of iptables.
19629 @item @code{iptables} (default: @code{iptables})
19630 The iptables package that provides @code{iptables-restore} and
19631 @code{ip6tables-restore}.
19632 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
19633 The iptables rules to use. It will be passed to @code{iptables-restore}.
19634 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
19636 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
19637 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
19638 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
19644 @defvr {Scheme Variable} nftables-service-type
19645 This is the service type to set up a nftables configuration. nftables is a
19646 netfilter project that aims to replace the existing iptables, ip6tables,
19647 arptables and ebtables framework. It provides a new packet filtering
19648 framework, a new user-space utility @command{nft}, and a compatibility layer
19649 for iptables. This service comes with a default ruleset
19650 @code{%default-nftables-ruleset} that rejecting all incoming connections
19651 except those to the ssh port 22. To use it, simply write:
19654 (service nftables-service-type)
19658 @deftp {Data Type} nftables-configuration
19659 The data type representing the configuration of nftables.
19662 @item @code{package} (default: @code{nftables})
19663 The nftables package that provides @command{nft}.
19664 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
19665 The nftables ruleset to use. This may be any ``file-like'' object
19666 (@pxref{G-Expressions, file-like objects}).
19670 @cindex NTP (Network Time Protocol), service
19671 @cindex ntpd, service for the Network Time Protocol daemon
19672 @cindex real time clock
19673 @defvr {Scheme Variable} ntp-service-type
19674 This is the type of the service running the @uref{https://www.ntp.org,
19675 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
19676 system clock synchronized with that of the specified NTP servers.
19678 The value of this service is an @code{ntpd-configuration} object, as described
19682 @deftp {Data Type} ntp-configuration
19683 This is the data type for the NTP service configuration.
19686 @item @code{servers} (default: @code{%ntp-servers})
19687 This is the list of servers (@code{<ntp-server>} records) with which
19688 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
19691 @item @code{allow-large-adjustment?} (default: @code{#t})
19692 This determines whether @command{ntpd} is allowed to make an initial
19693 adjustment of more than 1,000 seconds.
19695 @item @code{ntp} (default: @code{ntp})
19696 The NTP package to use.
19700 @defvr {Scheme Variable} %ntp-servers
19701 List of host names used as the default NTP servers. These are servers of the
19702 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
19705 @deftp {Data Type} ntp-server
19706 The data type representing the configuration of a NTP server.
19709 @item @code{type} (default: @code{'server})
19710 The type of the NTP server, given as a symbol. One of @code{'pool},
19711 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
19713 @item @code{address}
19714 The address of the server, as a string.
19716 @item @code{options}
19717 NTPD options to use with that specific server, given as a list of option names
19718 and/or of option names and values tuples. The following example define a server
19719 to use with the options @option{iburst} and @option{prefer}, as well as
19720 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
19725 (address "some.ntp.server.org")
19726 (options `(iburst (version 3) (maxpoll 16) prefer))))
19732 @deffn {Scheme Procedure} openntpd-service-type
19733 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
19734 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
19735 clock synchronized with that of the given servers.
19739 openntpd-service-type
19740 (openntpd-configuration
19741 (listen-on '("127.0.0.1" "::1"))
19742 (sensor '("udcf0 correction 70000"))
19743 (constraint-from '("www.gnu.org"))
19744 (constraints-from '("https://www.google.com/"))))
19749 @defvr {Scheme Variable} %openntpd-servers
19750 This variable is a list of the server addresses defined in
19751 @code{%ntp-servers}.
19754 @deftp {Data Type} openntpd-configuration
19756 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
19757 The openntpd executable to use.
19758 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
19759 A list of local IP addresses or hostnames the ntpd daemon should listen on.
19760 @item @code{query-from} (default: @code{'()})
19761 A list of local IP address the ntpd daemon should use for outgoing queries.
19762 @item @code{sensor} (default: @code{'()})
19763 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
19764 will listen to each sensor that actually exists and ignore non-existent ones.
19765 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
19767 @item @code{server} (default: @code{'()})
19768 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
19769 @item @code{servers} (default: @code{%openntp-servers})
19770 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
19771 @item @code{constraint-from} (default: @code{'()})
19772 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
19773 This time information is not used for precision but acts as an authenticated
19774 constraint, thereby reducing the impact of unauthenticated NTP
19775 man-in-the-middle attacks.
19776 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
19778 @item @code{constraints-from} (default: @code{'()})
19779 As with constraint from, specify a list of URLs, IP addresses or hostnames of
19780 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
19781 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
19786 @deffn {Scheme variable} inetd-service-type
19787 This service runs the @command{inetd} (@pxref{inetd invocation,,,
19788 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
19789 connections on internet sockets, and lazily starts the specified server
19790 program when a connection is made on one of these sockets.
19792 The value of this service is an @code{inetd-configuration} object. The
19793 following example configures the @command{inetd} daemon to provide the
19794 built-in @command{echo} service, as well as an smtp service which
19795 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
19796 gateway @code{hostname}:
19801 (inetd-configuration
19805 (socket-type 'stream)
19812 (socket-type 'stream)
19816 (program (file-append openssh "/bin/ssh"))
19818 '("ssh" "-qT" "-i" "/path/to/ssh_key"
19819 "-W" "smtp-server:25" "user@@hostname")))))))
19822 See below for more details about @code{inetd-configuration}.
19825 @deftp {Data Type} inetd-configuration
19826 Data type representing the configuration of @command{inetd}.
19829 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
19830 The @command{inetd} executable to use.
19832 @item @code{entries} (default: @code{'()})
19833 A list of @command{inetd} service entries. Each entry should be created
19834 by the @code{inetd-entry} constructor.
19838 @deftp {Data Type} inetd-entry
19839 Data type representing an entry in the @command{inetd} configuration.
19840 Each entry corresponds to a socket where @command{inetd} will listen for
19844 @item @code{node} (default: @code{#f})
19845 Optional string, a comma-separated list of local addresses
19846 @command{inetd} should use when listening for this service.
19847 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
19848 description of all options.
19850 A string, the name must correspond to an entry in @code{/etc/services}.
19851 @item @code{socket-type}
19852 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
19854 @item @code{protocol}
19855 A string, must correspond to an entry in @code{/etc/protocols}.
19856 @item @code{wait?} (default: @code{#t})
19857 Whether @command{inetd} should wait for the server to exit before
19858 listening to new service requests.
19860 A string containing the user (and, optionally, group) name of the user
19861 as whom the server should run. The group name can be specified in a
19862 suffix, separated by a colon or period, i.e.@: @code{"user"},
19863 @code{"user:group"} or @code{"user.group"}.
19864 @item @code{program} (default: @code{"internal"})
19865 The server program which will serve the requests, or @code{"internal"}
19866 if @command{inetd} should use a built-in service.
19867 @item @code{arguments} (default: @code{'()})
19868 A list strings or file-like objects, which are the server program's
19869 arguments, starting with the zeroth argument, i.e.@: the name of the
19870 program itself. For @command{inetd}'s internal services, this entry
19871 must be @code{'()} or @code{'("internal")}.
19874 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
19875 detailed discussion of each configuration field.
19878 @cindex opendht, distributed hash table network service
19879 @cindex dhtproxy, for use with jami
19880 @defvr {Scheme Variable} opendht-service-type
19881 This is the type of the service running a @uref{https://opendht.net,
19882 OpenDHT} node, @command{dhtnode}. The daemon can be used to host your
19883 own proxy service to the distributed hash table (DHT), for example to
19884 connect to with Jami, among other applications.
19886 @quotation Important
19887 When using the OpenDHT proxy server, the IP addresses it ``sees'' from
19888 the clients should be addresses reachable from other peers. In practice
19889 this means that a publicly reachable address is best suited for a proxy
19890 server, outside of your private network. For example, hosting the proxy
19891 server on a IPv4 private local network and exposing it via port
19892 forwarding could work for external peers, but peers local to the proxy
19893 would have their private addresses shared with the external peers,
19894 leading to connectivity problems.
19897 The value of this service is a @code{opendht-configuration} object, as
19901 @c The fields documentation has been auto-generated using the
19902 @c configuration->documentation procedure from
19903 @c (gnu services configuration).
19904 @deftp {Data Type} opendht-configuration
19905 Available @code{opendht-configuration} fields are:
19908 @item @code{opendht} (default: @code{opendht}) (type: file-like)
19909 The @code{opendht} package to use.
19911 @item @code{peer-discovery?} (default: @code{#f}) (type: boolean)
19912 Whether to enable the multicast local peer discovery mechanism.
19914 @item @code{enable-logging?} (default: @code{#f}) (type: boolean)
19915 Whether to enable logging messages to syslog. It is disabled by default
19916 as it is rather verbose.
19918 @item @code{debug?} (default: @code{#f}) (type: boolean)
19919 Whether to enable debug-level logging messages. This has no effect if
19920 logging is disabled.
19922 @item @code{bootstrap-host} (default: @code{"bootstrap.jami.net:4222"}) (type: maybe-string)
19923 The node host name that is used to make the first connection to the
19924 network. A specific port value can be provided by appending the
19925 @code{:PORT} suffix. By default, it uses the Jami bootstrap nodes, but
19926 any host can be specified here. It's also possible to disable
19927 bootstrapping by explicitly setting this field to the
19928 @code{%unset-value} value.
19930 @item @code{port} (default: @code{4222}) (type: maybe-number)
19931 The UDP port to bind to. When left unspecified, an available port is
19932 automatically selected.
19934 @item @code{proxy-server-port} (type: maybe-number)
19935 Spawn a proxy server listening on the specified port.
19937 @item @code{proxy-server-port-tls} (type: maybe-number)
19938 Spawn a proxy server listening to TLS connections on the specified port.
19944 @defvr {Scheme Variable} tor-service-type
19945 This is the type for a service that runs the @uref{https://torproject.org,
19946 Tor} anonymous networking daemon. The service is configured using a
19947 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
19948 @code{tor} unprivileged user, which is a member of the @code{tor} group.
19952 @deftp {Data Type} tor-configuration
19954 @item @code{tor} (default: @code{tor})
19955 The package that provides the Tor daemon. This package is expected to provide
19956 the daemon at @file{bin/tor} relative to its output directory. The default
19957 package is the @uref{https://www.torproject.org, Tor Project's}
19960 @item @code{config-file} (default: @code{(plain-file "empty" "")})
19961 The configuration file to use. It will be appended to a default configuration
19962 file, and the final configuration file will be passed to @code{tor} via its
19963 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
19964 file-like objects}). See @code{man tor} for details on the configuration file
19967 @item @code{hidden-services} (default: @code{'()})
19968 The list of @code{<hidden-service>} records to use. For any hidden service
19969 you include in this list, appropriate configuration to enable the hidden
19970 service will be automatically added to the default configuration file. You
19971 may conveniently create @code{<hidden-service>} records using the
19972 @code{tor-hidden-service} procedure described below.
19974 @item @code{socks-socket-type} (default: @code{'tcp})
19975 The default socket type that Tor should use for its SOCKS socket. This must
19976 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
19977 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
19978 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
19979 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
19982 If you want to customize the SOCKS socket in more detail, leave
19983 @code{socks-socket-type} at its default value of @code{'tcp} and use
19984 @code{config-file} to override the default by providing your own
19985 @code{SocksPort} option.
19987 @item @code{control-socket?} (default: @code{#f})
19988 Whether or not to provide a ``control socket'' by which Tor can be
19989 controlled to, for instance, dynamically instantiate tor onion services.
19990 If @code{#t}, Tor will listen for control commands on the UNIX domain socket
19991 @file{/var/run/tor/control-sock}, which will be made writable by members of the
19997 @cindex hidden service
19998 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
19999 Define a new Tor @dfn{hidden service} called @var{name} and implementing
20000 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
20003 '((22 "127.0.0.1:22")
20004 (80 "127.0.0.1:8080"))
20007 In this example, port 22 of the hidden service is mapped to local port 22, and
20008 port 80 is mapped to local port 8080.
20010 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
20011 the @file{hostname} file contains the @code{.onion} host name for the hidden
20014 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
20015 project's documentation} for more information.
20018 The @code{(gnu services rsync)} module provides the following services:
20020 You might want an rsync daemon if you have files that you want available
20021 so anyone (or just yourself) can download existing files or upload new
20024 @deffn {Scheme Variable} rsync-service-type
20025 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
20026 The value for this service type is a
20027 @command{rsync-configuration} record as in this example:
20030 ;; Export two directories over rsync. By default rsync listens on
20031 ;; all the network interfaces.
20032 (service rsync-service-type
20033 (rsync-configuration
20034 (modules (list (rsync-module
20036 (file-name "/srv/zik")
20040 (file-name "/home/charlie/movies"))))))
20043 See below for details about @code{rsync-configuration}.
20046 @deftp {Data Type} rsync-configuration
20047 Data type representing the configuration for @code{rsync-service}.
20050 @item @code{package} (default: @var{rsync})
20051 @code{rsync} package to use.
20053 @item @code{address} (default: @code{#f})
20054 IP address on which @command{rsync} listens for incoming connections.
20055 If unspecified, it defaults to listening on all available addresses.
20057 @item @code{port-number} (default: @code{873})
20058 TCP port on which @command{rsync} listens for incoming connections. If port
20059 is less than @code{1024} @command{rsync} needs to be started as the
20060 @code{root} user and group.
20062 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
20063 Name of the file where @command{rsync} writes its PID.
20065 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
20066 Name of the file where @command{rsync} writes its lock file.
20068 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
20069 Name of the file where @command{rsync} writes its log file.
20071 @item @code{user} (default: @code{"root"})
20072 Owner of the @code{rsync} process.
20074 @item @code{group} (default: @code{"root"})
20075 Group of the @code{rsync} process.
20077 @item @code{uid} (default: @code{"rsyncd"})
20078 User name or user ID that file transfers to and from that module should take
20079 place as when the daemon was run as @code{root}.
20081 @item @code{gid} (default: @code{"rsyncd"})
20082 Group name or group ID that will be used when accessing the module.
20084 @item @code{modules} (default: @code{%default-modules})
20085 List of ``modules''---i.e., directories exported over rsync. Each
20086 element must be a @code{rsync-module} record, as described below.
20090 @deftp {Data Type} rsync-module
20091 This is the data type for rsync ``modules''. A module is a directory
20092 exported over the rsync protocol. The available fields are as follows:
20096 The module name. This is the name that shows up in URLs. For example,
20097 if the module is called @code{music}, the corresponding URL will be
20098 @code{rsync://host.example.org/music}.
20100 @item @code{file-name}
20101 Name of the directory being exported.
20103 @item @code{comment} (default: @code{""})
20104 Comment associated with the module. Client user interfaces may display
20105 it when they obtain the list of available modules.
20107 @item @code{read-only?} (default: @code{#t})
20108 Whether or not client will be able to upload files. If this is false,
20109 the uploads will be authorized if permissions on the daemon side permit
20112 @item @code{chroot?} (default: @code{#t})
20113 When this is true, the rsync daemon changes root to the module's
20114 directory before starting file transfers with the client. This improves
20115 security, but requires rsync to run as root.
20117 @item @code{timeout} (default: @code{300})
20118 Idle time in seconds after which the daemon closes a connection with the
20123 The @code{(gnu services syncthing)} module provides the following services:
20126 You might want a syncthing daemon if you have files between two or more
20127 computers and want to sync them in real time, safely protected from
20130 @deffn {Scheme Variable} syncthing-service-type
20131 This is the service type for the @uref{https://syncthing.net/,
20132 syncthing} daemon, The value for this service type is a
20133 @command{syncthing-configuration} record as in this example:
20136 (service syncthing-service-type
20137 (syncthing-configuration (user "alice")))
20140 See below for details about @code{syncthing-configuration}.
20142 @deftp {Data Type} syncthing-configuration
20143 Data type representing the configuration for @code{syncthing-service-type}.
20146 @item @code{syncthing} (default: @var{syncthing})
20147 @code{syncthing} package to use.
20149 @item @code{arguments} (default: @var{'()})
20150 List of command-line arguments passing to @code{syncthing} binary.
20152 @item @code{logflags} (default: @var{0})
20153 Sum of logging flags, see
20154 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
20156 @item @code{user} (default: @var{#f})
20157 The user as which the Syncthing service is to be run.
20158 This assumes that the specified user exists.
20160 @item @code{group} (default: @var{"users"})
20161 The group as which the Syncthing service is to be run.
20162 This assumes that the specified group exists.
20164 @item @code{home} (default: @var{#f})
20165 Common configuration and data directory. The default configuration
20166 directory is @file{$HOME} of the specified Syncthing @code{user}.
20172 Furthermore, @code{(gnu services ssh)} provides the following services.
20176 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
20177 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
20178 [#:allow-empty-passwords? #f] [#:root-login? #f] @
20179 [#:syslog-output? #t] [#:x11-forwarding? #t] @
20180 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
20181 [#:public-key-authentication? #t] [#:initialize? #t]
20182 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
20183 @var{host-key} must designate a file containing the host key, and readable
20186 When @var{daemonic?} is true, @command{lshd} will detach from the
20187 controlling terminal and log its output to syslogd, unless one sets
20188 @var{syslog-output?} to false. Obviously, it also makes lsh-service
20189 depend on existence of syslogd service. When @var{pid-file?} is true,
20190 @command{lshd} writes its PID to the file called @var{pid-file}.
20192 When @var{initialize?} is true, automatically create the seed and host key
20193 upon service activation if they do not exist yet. This may take long and
20194 require interaction.
20196 When @var{initialize?} is false, it is up to the user to initialize the
20197 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
20198 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
20199 basics,,, lsh, LSH Manual}).
20201 When @var{interfaces} is empty, lshd listens for connections on all the
20202 network interfaces; otherwise, @var{interfaces} must be a list of host names
20205 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
20206 passwords, and @var{root-login?} specifies whether to accept log-ins as
20209 The other options should be self-descriptive.
20214 @deffn {Scheme Variable} openssh-service-type
20215 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
20216 shell daemon, @command{sshd}. Its value must be an
20217 @code{openssh-configuration} record as in this example:
20220 (service openssh-service-type
20221 (openssh-configuration
20222 (x11-forwarding? #t)
20223 (permit-root-login 'prohibit-password)
20225 `(("alice" ,(local-file "alice.pub"))
20226 ("bob" ,(local-file "bob.pub"))))))
20229 See below for details about @code{openssh-configuration}.
20231 This service can be extended with extra authorized keys, as in this
20235 (service-extension openssh-service-type
20236 (const `(("charlie"
20237 ,(local-file "charlie.pub")))))
20241 @deftp {Data Type} openssh-configuration
20242 This is the configuration record for OpenSSH's @command{sshd}.
20245 @item @code{openssh} (default @var{openssh})
20246 The OpenSSH package to use.
20248 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
20249 Name of the file where @command{sshd} writes its PID.
20251 @item @code{port-number} (default: @code{22})
20252 TCP port on which @command{sshd} listens for incoming connections.
20254 @item @code{max-connections} (default: @code{200})
20255 Hard limit on the maximum number of simultaneous client connections,
20256 enforced by the inetd-style Shepherd service (@pxref{Service De- and
20257 Constructors, @code{make-inetd-constructor},, shepherd, The GNU Shepherd
20260 @item @code{permit-root-login} (default: @code{#f})
20261 This field determines whether and when to allow logins as root. If
20262 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
20263 If it's the symbol @code{'prohibit-password}, then root logins are
20264 permitted but not with password-based authentication.
20266 @item @code{allow-empty-passwords?} (default: @code{#f})
20267 When true, users with empty passwords may log in. When false, they may
20270 @item @code{password-authentication?} (default: @code{#t})
20271 When true, users may log in with their password. When false, they have
20272 other authentication methods.
20274 @item @code{public-key-authentication?} (default: @code{#t})
20275 When true, users may log in using public key authentication. When
20276 false, users have to use other authentication method.
20278 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
20279 This is used only by protocol version 2.
20281 @item @code{x11-forwarding?} (default: @code{#f})
20282 When true, forwarding of X11 graphical client connections is
20283 enabled---in other words, @command{ssh} options @option{-X} and
20284 @option{-Y} will work.
20286 @item @code{allow-agent-forwarding?} (default: @code{#t})
20287 Whether to allow agent forwarding.
20289 @item @code{allow-tcp-forwarding?} (default: @code{#t})
20290 Whether to allow TCP forwarding.
20292 @item @code{gateway-ports?} (default: @code{#f})
20293 Whether to allow gateway ports.
20295 @item @code{challenge-response-authentication?} (default: @code{#f})
20296 Specifies whether challenge response authentication is allowed (e.g.@: via
20299 @item @code{use-pam?} (default: @code{#t})
20300 Enables the Pluggable Authentication Module interface. If set to
20301 @code{#t}, this will enable PAM authentication using
20302 @code{challenge-response-authentication?} and
20303 @code{password-authentication?}, in addition to PAM account and session
20304 module processing for all authentication types.
20306 Because PAM challenge response authentication usually serves an
20307 equivalent role to password authentication, you should disable either
20308 @code{challenge-response-authentication?} or
20309 @code{password-authentication?}.
20311 @item @code{print-last-log?} (default: @code{#t})
20312 Specifies whether @command{sshd} should print the date and time of the
20313 last user login when a user logs in interactively.
20315 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
20316 Configures external subsystems (e.g.@: file transfer daemon).
20318 This is a list of two-element lists, each of which containing the
20319 subsystem name and a command (with optional arguments) to execute upon
20322 The command @command{internal-sftp} implements an in-process SFTP
20323 server. Alternatively, one can specify the @command{sftp-server} command:
20325 (service openssh-service-type
20326 (openssh-configuration
20328 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
20331 @item @code{accepted-environment} (default: @code{'()})
20332 List of strings describing which environment variables may be exported.
20334 Each string gets on its own line. See the @code{AcceptEnv} option in
20335 @code{man sshd_config}.
20337 This example allows ssh-clients to export the @env{COLORTERM} variable.
20338 It is set by terminal emulators, which support colors. You can use it in
20339 your shell's resource file to enable colors for the prompt and commands
20340 if this variable is set.
20343 (service openssh-service-type
20344 (openssh-configuration
20345 (accepted-environment '("COLORTERM"))))
20348 @item @code{authorized-keys} (default: @code{'()})
20349 @cindex authorized keys, SSH
20350 @cindex SSH authorized keys
20351 This is the list of authorized keys. Each element of the list is a user
20352 name followed by one or more file-like objects that represent SSH public
20356 (openssh-configuration
20358 `(("rekado" ,(local-file "rekado.pub"))
20359 ("chris" ,(local-file "chris.pub"))
20360 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
20364 registers the specified public keys for user accounts @code{rekado},
20365 @code{chris}, and @code{root}.
20367 Additional authorized keys can be specified @i{via}
20368 @code{service-extension}.
20370 Note that this does @emph{not} interfere with the use of
20371 @file{~/.ssh/authorized_keys}.
20373 @item @code{generate-host-keys?} (default: @code{#t})
20374 Whether to generate host key pairs with @command{ssh-keygen -A} under
20375 @file{/etc/ssh} if there are none.
20377 Generating key pairs takes a few seconds when enough entropy is
20378 available and is only done once. You might want to turn it off for
20379 instance in a virtual machine that does not need it because host keys
20380 are provided in some other way, and where the extra boot time is a
20383 @item @code{log-level} (default: @code{'info})
20384 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
20385 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
20386 page for @file{sshd_config} for the full list of level names.
20388 @item @code{extra-content} (default: @code{""})
20389 This field can be used to append arbitrary text to the configuration file. It
20390 is especially useful for elaborate configurations that cannot be expressed
20391 otherwise. This configuration, for example, would generally disable root
20392 logins, but permit them from one specific IP address:
20395 (openssh-configuration
20397 Match Address 192.168.0.1
20398 PermitRootLogin yes"))
20404 @deffn {Scheme Procedure} dropbear-service [@var{config}]
20405 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
20406 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
20409 For example, to specify a Dropbear service listening on port 1234, add
20410 this call to the operating system's @code{services} field:
20413 (dropbear-service (dropbear-configuration
20414 (port-number 1234)))
20418 @deftp {Data Type} dropbear-configuration
20419 This data type represents the configuration of a Dropbear SSH daemon.
20422 @item @code{dropbear} (default: @var{dropbear})
20423 The Dropbear package to use.
20425 @item @code{port-number} (default: 22)
20426 The TCP port where the daemon waits for incoming connections.
20428 @item @code{syslog-output?} (default: @code{#t})
20429 Whether to enable syslog output.
20431 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
20432 File name of the daemon's PID file.
20434 @item @code{root-login?} (default: @code{#f})
20435 Whether to allow @code{root} logins.
20437 @item @code{allow-empty-passwords?} (default: @code{#f})
20438 Whether to allow empty passwords.
20440 @item @code{password-authentication?} (default: @code{#t})
20441 Whether to enable password-based authentication.
20446 @deffn {Scheme Variable} autossh-service-type
20447 This is the type for the @uref{https://www.harding.motd.ca/autossh,
20448 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
20449 restarting it as necessary should it die or stop passing traffic.
20450 AutoSSH can be run manually from the command-line by passing arguments
20451 to the binary @command{autossh} from the package @code{autossh}, but it
20452 can also be run as a Guix service. This latter use case is documented
20455 AutoSSH can be used to forward local traffic to a remote machine using
20456 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
20459 For example, to specify a service running autossh as the user
20460 @code{pino} and forwarding all local connections to port @code{8081} to
20461 @code{remote:8081} using an SSH tunnel, add this call to the operating
20462 system's @code{services} field:
20465 (service autossh-service-type
20466 (autossh-configuration
20468 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
20472 @deftp {Data Type} autossh-configuration
20473 This data type represents the configuration of an AutoSSH service.
20477 @item @code{user} (default @code{"autossh"})
20478 The user as which the AutoSSH service is to be run.
20479 This assumes that the specified user exists.
20481 @item @code{poll} (default @code{600})
20482 Specifies the connection poll time in seconds.
20484 @item @code{first-poll} (default @code{#f})
20485 Specifies how many seconds AutoSSH waits before the first connection
20486 test. After this first test, polling is resumed at the pace defined in
20487 @code{poll}. When set to @code{#f}, the first poll is not treated
20488 specially and will also use the connection poll specified in
20491 @item @code{gate-time} (default @code{30})
20492 Specifies how many seconds an SSH connection must be active before it is
20493 considered successful.
20495 @item @code{log-level} (default @code{1})
20496 The log level, corresponding to the levels used by syslog---so @code{0}
20497 is the most silent while @code{7} is the chattiest.
20499 @item @code{max-start} (default @code{#f})
20500 The maximum number of times SSH may be (re)started before AutoSSH exits.
20501 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
20503 @item @code{message} (default @code{""})
20504 The message to append to the echo message sent when testing connections.
20506 @item @code{port} (default @code{"0"})
20507 The ports used for monitoring the connection. When set to @code{"0"},
20508 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
20509 a positive integer, ports @var{n} and @var{n}+1 are used for
20510 monitoring the connection, such that port @var{n} is the base
20511 monitoring port and @code{n+1} is the echo port. When set to
20512 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
20513 integers, the ports @var{n} and @var{m} are used for monitoring the
20514 connection, such that port @var{n} is the base monitoring port and
20515 @var{m} is the echo port.
20517 @item @code{ssh-options} (default @code{'()})
20518 The list of command-line arguments to pass to @command{ssh} when it is
20519 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
20520 may cause undefined behaviour.
20526 @deffn {Scheme Variable} webssh-service-type
20527 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
20528 program that runs a web SSH client. WebSSH can be run manually from the
20529 command-line by passing arguments to the binary @command{wssh} from the
20530 package @code{webssh}, but it can also be run as a Guix service. This
20531 latter use case is documented here.
20533 For example, to specify a service running WebSSH on loopback interface
20534 on port @code{8888} with reject policy with a list of allowed to
20535 connection hosts, and NGINX as a reverse-proxy to this service listening
20536 for HTTPS connection, add this call to the operating system's
20537 @code{services} field:
20540 (service webssh-service-type
20541 (webssh-configuration (address "127.0.0.1")
20544 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
20545 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
20547 (service nginx-service-type
20548 (nginx-configuration
20551 (nginx-server-configuration
20552 (inherit %webssh-configuration-nginx)
20553 (server-name '("webssh.example.com"))
20554 (listen '("443 ssl"))
20555 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
20556 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
20558 (cons (nginx-location-configuration
20559 (uri "/.well-known")
20560 (body '("root /var/www;")))
20561 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
20565 @deftp {Data Type} webssh-configuration
20566 Data type representing the configuration for @code{webssh-service}.
20569 @item @code{package} (default: @var{webssh})
20570 @code{webssh} package to use.
20572 @item @code{user-name} (default: @var{"webssh"})
20573 User name or user ID that file transfers to and from that module should take
20576 @item @code{group-name} (default: @var{"webssh"})
20577 Group name or group ID that will be used when accessing the module.
20579 @item @code{address} (default: @var{#f})
20580 IP address on which @command{webssh} listens for incoming connections.
20582 @item @code{port} (default: @var{8888})
20583 TCP port on which @command{webssh} listens for incoming connections.
20585 @item @code{policy} (default: @var{#f})
20586 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
20588 @item @code{known-hosts} (default: @var{'()})
20589 List of hosts which allowed for SSH connection from @command{webssh}.
20591 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
20592 Name of the file where @command{webssh} writes its log file.
20594 @item @code{log-level} (default: @var{#f})
20600 @defvr {Scheme Variable} %facebook-host-aliases
20601 This variable contains a string for use in @file{/etc/hosts}
20602 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
20603 line contains a entry that maps a known server name of the Facebook
20604 on-line service---e.g., @code{www.facebook.com}---to the local
20605 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
20607 This variable is typically used in the @code{hosts-file} field of an
20608 @code{operating-system} declaration (@pxref{operating-system Reference,
20609 @file{/etc/hosts}}):
20612 (use-modules (gnu) (guix))
20615 (host-name "mymachine")
20618 ;; Create a /etc/hosts file with aliases for "localhost"
20619 ;; and "mymachine", as well as for Facebook servers.
20620 (plain-file "hosts"
20621 (string-append (local-host-aliases host-name)
20622 %facebook-host-aliases))))
20625 This mechanism can prevent programs running locally, such as Web
20626 browsers, from accessing Facebook.
20629 The @code{(gnu services avahi)} provides the following definition.
20631 @defvr {Scheme Variable} avahi-service-type
20632 This is the service that runs @command{avahi-daemon}, a system-wide
20633 mDNS/DNS-SD responder that allows for service discovery and
20634 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
20635 Its value must be an @code{avahi-configuration} record---see below.
20637 This service extends the name service cache daemon (nscd) so that it can
20638 resolve @code{.local} host names using
20639 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
20640 Service Switch}, for information on host name resolution.
20642 Additionally, add the @var{avahi} package to the system profile so that
20643 commands such as @command{avahi-browse} are directly usable.
20646 @deftp {Data Type} avahi-configuration
20647 Data type representation the configuration for Avahi.
20651 @item @code{host-name} (default: @code{#f})
20652 If different from @code{#f}, use that as the host name to
20653 publish for this machine; otherwise, use the machine's actual host name.
20655 @item @code{publish?} (default: @code{#t})
20656 When true, allow host names and services to be published (broadcast) over the
20659 @item @code{publish-workstation?} (default: @code{#t})
20660 When true, @command{avahi-daemon} publishes the machine's host name and IP
20661 address via mDNS on the local network. To view the host names published on
20662 your local network, you can run:
20665 avahi-browse _workstation._tcp
20668 @item @code{wide-area?} (default: @code{#f})
20669 When true, DNS-SD over unicast DNS is enabled.
20671 @item @code{ipv4?} (default: @code{#t})
20672 @itemx @code{ipv6?} (default: @code{#t})
20673 These fields determine whether to use IPv4/IPv6 sockets.
20675 @item @code{domains-to-browse} (default: @code{'()})
20676 This is a list of domains to browse.
20680 @deffn {Scheme Variable} openvswitch-service-type
20681 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
20682 service, whose value should be an @code{openvswitch-configuration}
20686 @deftp {Data Type} openvswitch-configuration
20687 Data type representing the configuration of Open vSwitch, a multilayer
20688 virtual switch which is designed to enable massive network automation
20689 through programmatic extension.
20692 @item @code{package} (default: @var{openvswitch})
20693 Package object of the Open vSwitch.
20698 @defvr {Scheme Variable} pagekite-service-type
20699 This is the service type for the @uref{https://pagekite.net, PageKite} service,
20700 a tunneling solution for making localhost servers publicly visible, even from
20701 behind restrictive firewalls or NAT without forwarded ports. The value for
20702 this service type is a @code{pagekite-configuration} record.
20704 Here's an example exposing the local HTTP and SSH daemons:
20707 (service pagekite-service-type
20708 (pagekite-configuration
20709 (kites '("http:@@kitename:localhost:80:@@kitesecret"
20710 "raw/22:@@kitename:localhost:22:@@kitesecret"))
20711 (extra-file "/etc/pagekite.rc")))
20715 @deftp {Data Type} pagekite-configuration
20716 Data type representing the configuration of PageKite.
20719 @item @code{package} (default: @var{pagekite})
20720 Package object of PageKite.
20722 @item @code{kitename} (default: @code{#f})
20723 PageKite name for authenticating to the frontend server.
20725 @item @code{kitesecret} (default: @code{#f})
20726 Shared secret for authenticating to the frontend server. You should probably
20727 put this inside @code{extra-file} instead.
20729 @item @code{frontend} (default: @code{#f})
20730 Connect to the named PageKite frontend server instead of the
20731 @uref{https://pagekite.net,,pagekite.net} service.
20733 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
20734 List of service kites to use. Exposes HTTP on port 80 by default. The format
20735 is @code{proto:kitename:host:port:secret}.
20737 @item @code{extra-file} (default: @code{#f})
20738 Extra configuration file to read, which you are expected to create manually.
20739 Use this to add additional options and manage shared secrets out-of-band.
20744 @defvr {Scheme Variable} yggdrasil-service-type
20745 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
20746 Yggdrasil network}, an early-stage implementation of a fully end-to-end
20747 encrypted IPv6 network.
20750 Yggdrasil provides name-independent routing with cryptographically generated
20751 addresses. Static addressing means you can keep the same address as long as
20752 you want, even if you move to a new location, or generate a new address (by
20753 generating new keys) whenever you want.
20754 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
20757 Pass it a value of @code{yggdrasil-configuration} to connect it to public
20758 peers and/or local peers.
20760 Here is an example using public peers and a static address. The static
20761 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
20762 (the default value for @code{config-file}).
20765 ;; part of the operating-system declaration
20766 (service yggdrasil-service-type
20767 (yggdrasil-configuration
20768 (autoconf? #f) ;; use only the public peers
20771 ;; https://github.com/yggdrasil-network/public-peers
20772 '((peers . #("tcp://1.2.3.4:1337"))))
20773 ;; /etc/yggdrasil-private.conf is the default value for config-file
20777 # sample content for /etc/yggdrasil-private.conf
20779 # Your public key. Your peers may ask you for this to put
20780 # into their AllowedPublicKeys configuration.
20781 PublicKey: 64277...
20783 # Your private key. DO NOT share this with anyone!
20784 PrivateKey: 5c750...
20789 @deftp {Data Type} yggdrasil-configuration
20790 Data type representing the configuration of Yggdrasil.
20793 @item @code{package} (default: @code{yggdrasil})
20794 Package object of Yggdrasil.
20796 @item @code{json-config} (default: @code{'()})
20797 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
20798 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
20799 the Guix store, which is readable to all users. @strong{Do not store your
20800 private keys in it}. See the output of @code{yggdrasil -genconf} for a
20801 quick overview of valid keys and their default values.
20803 @item @code{autoconf?} (default: @code{#f})
20804 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
20805 and peer with IPv6 neighbors.
20807 @item @code{log-level} (default: @code{'info})
20808 How much detail to include in logs. Use @code{'debug} for more detail.
20810 @item @code{log-to} (default: @code{'stdout})
20811 Where to send logs. By default, the service logs standard output to
20812 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
20813 sends output to the running syslog service.
20815 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
20816 What HJSON file to load sensitive data from. This is where private keys
20817 should be stored, which are necessary to specify if you don't want a
20818 randomized address after each restart. Use @code{#f} to disable. Options
20819 defined in this file take precedence over @code{json-config}. Use the output
20820 of @code{yggdrasil -genconf} as a starting point. To configure a static
20821 address, delete everything except these options:
20824 @item @code{EncryptionPublicKey}
20825 @item @code{EncryptionPrivateKey}
20826 @item @code{SigningPublicKey}
20827 @item @code{SigningPrivateKey}
20833 @defvr {Scheme Variable} ipfs-service-type
20834 The service type for connecting to the @uref{https://ipfs.io,IPFS network},
20835 a global, versioned, peer-to-peer file system. Pass it a
20836 @code{ipfs-configuration} to change the ports used for the gateway and API.
20838 Here's an example configuration, using some non-standard ports:
20841 (service ipfs-service-type
20842 (ipfs-configuration
20843 (gateway "/ip4/127.0.0.1/tcp/8880")
20844 (api "/ip4/127.0.0.1/tcp/8881")))
20848 @deftp {Data Type} ipfs-configuration
20849 Data type representing the configuration of IPFS.
20852 @item @code{package} (default: @code{go-ipfs})
20853 Package object of IPFS.
20855 @item @code{gateway} (default: @code{"/ip4/127.0.0.1/tcp/8082"})
20856 Address of the gateway, in ‘multiaddress’ format.
20858 @item @code{api} (default: @code{"/ip4/127.0.0.1/tcp/5001"})
20859 Address of the API endpoint, in ‘multiaddress’ format.
20864 @deffn {Scheme Variable} keepalived-service-type
20865 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
20866 routing software, @command{keepalived}. Its value must be an
20867 @code{keepalived-configuration} record as in this example for master
20871 (service keepalived-service-type
20872 (keepalived-configuration
20873 (config-file (local-file "keepalived-master.conf"))))
20876 where @file{keepalived-master.conf}:
20879 vrrp_instance my-group @{
20882 virtual_router_id 100
20884 unicast_peer @{ 10.0.0.2 @}
20885 virtual_ipaddress @{
20891 and for backup machine:
20894 (service keepalived-service-type
20895 (keepalived-configuration
20896 (config-file (local-file "keepalived-backup.conf"))))
20899 where @file{keepalived-backup.conf}:
20902 vrrp_instance my-group @{
20905 virtual_router_id 100
20907 unicast_peer @{ 10.0.0.3 @}
20908 virtual_ipaddress @{
20915 @node Unattended Upgrades
20916 @subsection Unattended Upgrades
20918 @cindex unattended upgrades
20919 @cindex upgrades, unattended
20920 Guix provides a service to perform @emph{unattended upgrades}:
20921 periodically, the system automatically reconfigures itself from the
20922 latest Guix. Guix System has several properties that make unattended
20927 upgrades are transactional (either the upgrade succeeds or it fails, but
20928 you cannot end up with an ``in-between'' system state);
20930 the upgrade log is kept---you can view it with @command{guix system
20931 list-generations}---and you can roll back to any previous generation,
20932 should the upgraded system fail to behave as intended;
20934 channel code is authenticated so you know you can only run genuine code
20935 (@pxref{Channels});
20937 @command{guix system reconfigure} prevents downgrades, which makes it
20938 immune to @dfn{downgrade attacks}.
20941 To set up unattended upgrades, add an instance of
20942 @code{unattended-upgrade-service-type} like the one below to the list of
20943 your operating system services:
20946 (service unattended-upgrade-service-type)
20949 The defaults above set up weekly upgrades: every Sunday at midnight.
20950 You do not need to provide the operating system configuration file: it
20951 uses @file{/run/current-system/configuration.scm}, which ensures it
20952 always uses your latest configuration---@pxref{provenance-service-type},
20953 for more information about this file.
20955 There are several things that can be configured, in particular the
20956 periodicity and services (daemons) to be restarted upon completion.
20957 When the upgrade is successful, the service takes care of deleting
20958 system generations older that some threshold, as per @command{guix
20959 system delete-generations}. See the reference below for details.
20961 To ensure that upgrades are actually happening, you can run
20962 @command{guix system describe}. To investigate upgrade failures, visit
20963 the unattended upgrade log file (see below).
20965 @defvr {Scheme Variable} unattended-upgrade-service-type
20966 This is the service type for unattended upgrades. It sets up an mcron
20967 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
20968 reconfigure} from the latest version of the specified channels.
20970 Its value must be a @code{unattended-upgrade-configuration} record (see
20974 @deftp {Data Type} unattended-upgrade-configuration
20975 This data type represents the configuration of the unattended upgrade
20976 service. The following fields are available:
20979 @item @code{schedule} (default: @code{"30 01 * * 0"})
20980 This is the schedule of upgrades, expressed as a gexp containing an
20981 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
20982 mcron, GNU@tie{}mcron}).
20984 @item @code{channels} (default: @code{#~%default-channels})
20985 This gexp specifies the channels to use for the upgrade
20986 (@pxref{Channels}). By default, the tip of the official @code{guix}
20989 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
20990 This field specifies the operating system configuration file to use.
20991 The default is to reuse the config file of the current configuration.
20993 There are cases, though, where referring to
20994 @file{/run/current-system/configuration.scm} is not enough, for instance
20995 because that file refers to extra files (SSH public keys, extra
20996 configuration files, etc.) @i{via} @code{local-file} and similar
20997 constructs. For those cases, we recommend something along these lines:
21000 (unattended-upgrade-configuration
21001 (operating-system-file
21002 (file-append (local-file "." "config-dir" #:recursive? #t)
21006 The effect here is to import all of the current directory into the
21007 store, and to refer to @file{config.scm} within that directory.
21008 Therefore, uses of @code{local-file} within @file{config.scm} will work
21009 as expected. @xref{G-Expressions}, for information about
21010 @code{local-file} and @code{file-append}.
21012 @item @code{services-to-restart} (default: @code{'(mcron)})
21013 This field specifies the Shepherd services to restart when the upgrade
21016 Those services are restarted right away upon completion, as with
21017 @command{herd restart}, which ensures that the latest version is
21018 running---remember that by default @command{guix system reconfigure}
21019 only restarts services that are not currently running, which is
21020 conservative: it minimizes disruption but leaves outdated services
21023 Use @command{herd status} to find out candidates for restarting.
21024 @xref{Services}, for general information about services. Common
21025 services to restart would include @code{ntpd} and @code{ssh-daemon}.
21027 By default, the @code{mcron} service is restarted. This ensures that
21028 the latest version of the unattended upgrade job will be used next time.
21030 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
21031 This is the expiration time in seconds for system generations. System
21032 generations older that this amount of time are deleted with
21033 @command{guix system delete-generations} when an upgrade completes.
21036 The unattended upgrade service does not run the garbage collector. You
21037 will probably want to set up your own mcron job to run @command{guix gc}
21041 @item @code{maximum-duration} (default: @code{3600})
21042 Maximum duration in seconds for the upgrade; past that time, the upgrade
21045 This is primarily useful to ensure the upgrade does not end up
21046 rebuilding or re-downloading ``the world''.
21048 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
21049 File where unattended upgrades are logged.
21054 @subsection X Window
21057 @cindex X Window System
21058 @cindex login manager
21059 Support for the X Window graphical display system---specifically
21060 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
21061 there is no @code{xorg-service} procedure. Instead, the X server is
21062 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
21065 @cindex GNOME, login manager
21067 GDM of course allows users to log in into window managers and desktop
21068 environments other than GNOME; for those using GNOME, GDM is required for
21069 features such as automatic screen locking.
21071 @cindex window manager
21072 To use X11, you must install at least one @dfn{window manager}---for
21073 example the @code{windowmaker} or @code{openbox} packages---preferably
21074 by adding it to the @code{packages} field of your operating system
21075 definition (@pxref{operating-system Reference, system-wide packages}).
21077 @anchor{wayland-gdm}
21078 GDM also supports Wayland: it can itself use Wayland instead of X11 for
21079 its user interface, and it can also start Wayland sessions. The former is
21080 required for the latter, to enable, set @code{wayland?} to @code{#t} in
21081 @code{gdm-configuration}.
21083 @defvr {Scheme Variable} gdm-service-type
21084 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
21085 Desktop Manager} (GDM), a program that manages graphical display servers and
21086 handles graphical user logins. Its value must be a @code{gdm-configuration}
21089 @cindex session types
21090 GDM looks for @dfn{session types} described by the @file{.desktop} files in
21091 @file{/run/current-system/profile/share/xsessions} (for X11 sessions) and
21092 @file{/run/current-system/profile/share/wayland-sessions} (for Wayland
21093 sessions) and allows users to choose a session from the log-in screen.
21094 Packages such as @code{gnome}, @code{xfce}, @code{i3} and @code{sway} provide
21095 @file{.desktop} files; adding them to the system-wide set of packages
21096 automatically makes them available at the log-in screen.
21098 In addition, @file{~/.xsession} files are honored. When available,
21099 @file{~/.xsession} must be an executable that starts a window manager
21100 and/or other X clients.
21103 @deftp {Data Type} gdm-configuration
21105 @item @code{auto-login?} (default: @code{#f})
21106 @itemx @code{default-user} (default: @code{#f})
21107 When @code{auto-login?} is false, GDM presents a log-in screen.
21109 When @code{auto-login?} is true, GDM logs in directly as
21110 @code{default-user}.
21112 @item @code{auto-suspend?} (default @code{#t})
21113 When true, GDM will automatically suspend to RAM when nobody is
21114 physically connected. When a machine is used via remote desktop or SSH,
21115 this should be set to false to avoid GDM interrupting remote sessions or
21116 rendering the machine unavailable.
21118 @item @code{debug?} (default: @code{#f})
21119 When true, GDM writes debug messages to its log.
21121 @item @code{gnome-shell-assets} (default: ...)
21122 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
21124 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
21125 Configuration of the Xorg graphical server.
21127 @item @code{x-session} (default: @code{(xinitrc)})
21128 Script to run before starting a X session.
21130 @item @code{xdmcp?} (default: @code{#f})
21131 When true, enable the X Display Manager Control Protocol (XDMCP). This
21132 should only be enabled in trusted environments, as the protocol is not
21133 secure. When enabled, GDM listens for XDMCP queries on the UDP port
21136 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
21137 File name of the @code{dbus-daemon} executable.
21139 @item @code{gdm} (default: @code{gdm})
21140 The GDM package to use.
21142 @item @code{wayland?} (default: @code{#f})
21143 When true, enables Wayland in GDM, necessary to use Wayland sessions.
21145 @item @code{wayland-session} (default: @code{gdm-wayland-session-wrapper})
21146 The Wayland session wrapper to use, needed to setup the
21151 @defvr {Scheme Variable} slim-service-type
21152 This is the type for the SLiM graphical login manager for X11.
21154 Like GDM, SLiM looks for session types described by @file{.desktop} files and
21155 allows users to choose a session from the log-in screen using @kbd{F1}. It
21156 also honors @file{~/.xsession} files.
21158 Unlike GDM, SLiM does not spawn the user session on a different VT after
21159 logging in, which means that you can only start one graphical session. If you
21160 want to be able to run multiple graphical sessions at the same time you have
21161 to add multiple SLiM services to your system services. The following example
21162 shows how to replace the default GDM service with two SLiM services on tty7
21166 (use-modules (gnu services)
21167 (gnu services desktop)
21168 (gnu services xorg))
21172 (services (cons* (service slim-service-type (slim-configuration
21175 (service slim-service-type (slim-configuration
21178 (modify-services %desktop-services
21179 (delete gdm-service-type)))))
21184 @deftp {Data Type} slim-configuration
21185 Data type representing the configuration of @code{slim-service-type}.
21188 @item @code{allow-empty-passwords?} (default: @code{#t})
21189 Whether to allow logins with empty passwords.
21191 @item @code{gnupg?} (default: @code{#f})
21192 If enabled, @code{pam-gnupg} will attempt to automatically unlock the
21193 user's GPG keys with the login password via @code{gpg-agent}. The
21194 keygrips of all keys to be unlocked should be written to
21195 @file{~/.pam-gnupg}, and can be queried with @code{gpg -K
21196 --with-keygrip}. Presetting passphrases must be enabled by adding
21197 @code{allow-preset-passphrase} in @file{~/.gnupg/gpg-agent.conf}.
21199 @item @code{auto-login?} (default: @code{#f})
21200 @itemx @code{default-user} (default: @code{""})
21201 When @code{auto-login?} is false, SLiM presents a log-in screen.
21203 When @code{auto-login?} is true, SLiM logs in directly as
21204 @code{default-user}.
21206 @item @code{theme} (default: @code{%default-slim-theme})
21207 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
21208 The graphical theme to use and its name.
21210 @item @code{auto-login-session} (default: @code{#f})
21211 If true, this must be the name of the executable to start as the default
21212 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
21214 If false, a session described by one of the available @file{.desktop}
21215 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
21219 You must install at least one window manager in the system profile or in
21220 your user profile. Failing to do that, if @code{auto-login-session} is
21221 false, you will be unable to log in.
21224 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
21225 Configuration of the Xorg graphical server.
21227 @item @code{display} (default @code{":0"})
21228 The display on which to start the Xorg graphical server.
21230 @item @code{vt} (default @code{"vt7"})
21231 The VT on which to start the Xorg graphical server.
21233 @item @code{xauth} (default: @code{xauth})
21234 The XAuth package to use.
21236 @item @code{shepherd} (default: @code{shepherd})
21237 The Shepherd package used when invoking @command{halt} and
21240 @item @code{sessreg} (default: @code{sessreg})
21241 The sessreg package used in order to register the session.
21243 @item @code{slim} (default: @code{slim})
21244 The SLiM package to use.
21248 @defvr {Scheme Variable} %default-theme
21249 @defvrx {Scheme Variable} %default-theme-name
21250 The default SLiM theme and its name.
21254 @cindex login manager
21256 @defvr {Scheme Variable} sddm-service-type
21257 This is the type of the service to run the
21258 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
21259 must be a @code{sddm-configuration} record (see below).
21261 Here's an example use:
21264 (service sddm-service-type
21265 (sddm-configuration
21266 (auto-login-user "alice")
21267 (auto-login-session "xfce.desktop")))
21271 @deftp {Data Type} sddm-configuration
21272 This data type represents the configuration of the SDDM login manager.
21273 The available fields are:
21276 @item @code{sddm} (default: @code{sddm})
21277 The SDDM package to use.
21279 @item @code{display-server} (default: "x11")
21280 Select display server to use for the greeter. Valid values are
21281 @samp{"x11"} or @samp{"wayland"}.
21283 @item @code{numlock} (default: "on")
21284 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
21286 @item @code{halt-command} (default @code{#~(string-append #$shepherd "/sbin/halt")})
21287 Command to run when halting.
21289 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
21290 Command to run when rebooting.
21292 @item @code{theme} (default "maldives")
21293 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
21294 @samp{"maldives"} or @samp{"maya"}.
21296 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
21297 Directory to look for themes.
21299 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
21300 Directory to look for faces.
21302 @item @code{default-path} (default "/run/current-system/profile/bin")
21303 Default PATH to use.
21305 @item @code{minimum-uid} (default: 1000)
21306 Minimum UID displayed in SDDM and allowed for log-in.
21308 @item @code{maximum-uid} (default: 2000)
21309 Maximum UID to display in SDDM.
21311 @item @code{remember-last-user?} (default #t)
21312 Remember last user.
21314 @item @code{remember-last-session?} (default #t)
21315 Remember last session.
21317 @item @code{hide-users} (default "")
21318 Usernames to hide from SDDM greeter.
21320 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
21321 Users with shells listed will be hidden from the SDDM greeter.
21323 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
21324 Script to run before starting a wayland session.
21326 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
21327 Directory to look for desktop files starting wayland sessions.
21329 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
21330 Configuration of the Xorg graphical server.
21332 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
21335 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
21338 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
21339 Script to run after starting xorg-server.
21341 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
21342 Script to run before stopping xorg-server.
21344 @item @code{xsession-command} (default: @code{xinitrc})
21345 Script to run before starting a X session.
21347 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
21348 Directory to look for desktop files starting X sessions.
21350 @item @code{minimum-vt} (default: 7)
21353 @item @code{auto-login-user} (default "")
21354 User account that will be automatically logged in.
21355 Setting this to the empty string disables auto-login.
21357 @item @code{auto-login-session} (default "")
21358 The @file{.desktop} file name to use as the auto-login session, or the empty string.
21360 @item @code{relogin?} (default #f)
21361 Relogin after logout.
21366 @cindex lightdm, graphical login manager
21367 @cindex display manager, lightdm
21369 @defvr {Scheme Variable} lightdm-service-type
21370 This is the type of the service to run the
21371 @url{https://github.com/canonical/lightdm,LightDM display manager}. Its
21372 value must be a @code{lightdm-configuration} record, which is documented
21373 below. Among its distinguishing features are TigerVNC integration for
21374 easily remoting your desktop as well as support for the XDMCP protocol,
21375 which can be used by remote clients to start a session from the login
21378 In its most basic form, it can be used simply as:
21381 (service lightdm-service-type)
21384 A more elaborate example making use of the VNC capabilities and enabling
21385 more features and verbose logs could look like:
21388 (service lightdm-service-type
21389 (lightdm-configuration
21390 (allow-empty-passwords? #t)
21393 (vnc-server-command
21394 (file-append tigervnc-server "/bin/Xvnc"
21395 " -SecurityTypes None"))
21397 (list (lightdm-seat-configuration
21399 (user-session "ratpoison"))))))
21403 @c The LightDM service documentation can be auto-generated via the
21404 @c 'generate-doc' procedure at the bottom of the (gnu services lightdm)
21406 @c %start of fragment
21407 @deftp {Data Type} lightdm-configuration
21408 Available @code{lightdm-configuration} fields are:
21411 @item @code{lightdm} (default: @code{lightdm}) (type: file-like)
21412 The lightdm package to use.
21414 @item @code{allow-empty-passwords?} (default: @code{#f}) (type: boolean)
21415 Whether users not having a password set can login.
21417 @item @code{debug?} (default: @code{#f}) (type: boolean)
21418 Enable verbose output.
21420 @item @code{xorg-configuration} (type: xorg-configuration)
21421 The default Xorg server configuration to use to generate the Xorg server
21422 start script. It can be refined per seat via the @code{xserver-command}
21423 of the @code{<lightdm-seat-configuration>} record, if desired.
21425 @item @code{greeters} (type: list-of-greeter-configurations)
21426 The LightDM greeter configurations specifying the greeters to use.
21428 @item @code{seats} (type: list-of-seat-configurations)
21429 The seat configurations to use. A LightDM seat is akin to a user.
21431 @item @code{xdmcp?} (default: @code{#f}) (type: boolean)
21432 Whether a XDMCP server should listen on port UDP 177.
21434 @item @code{xdmcp-listen-address} (type: maybe-string)
21435 The host or IP address the XDMCP server listens for incoming
21436 connections. When unspecified, listen on for any hosts/IP addresses.
21438 @item @code{vnc-server?} (default: @code{#f}) (type: boolean)
21439 Whether a VNC server is started.
21441 @item @code{vnc-server-command} (type: file-like)
21442 The Xvnc command to use for the VNC server, it's possible to provide
21443 extra options not otherwise exposed along the command, for example to
21447 (vnc-server-command (file-append tigervnc-server "/bin/Xvnc"
21448 " -SecurityTypes None" ))
21451 Or to set a PasswordFile for the classic (unsecure) VncAuth
21455 (vnc-server-command (file-append tigervnc-server "/bin/Xvnc"
21456 " -PasswordFile /var/lib/lightdm/.vnc/passwd"))
21459 The password file should be manually created using the
21460 @command{vncpasswd} command. Note that LightDM will create new sessions
21461 for VNC users, which means they need to authenticate in the same way as
21464 @item @code{vnc-server-listen-address} (type: maybe-string)
21465 The host or IP address the VNC server listens for incoming connections.
21466 When unspecified, listen for any hosts/IP addresses.
21468 @item @code{vnc-server-port} (default: @code{5900}) (type: number)
21469 The TCP port the VNC server should listen to.
21471 @item @code{extra-config} (default: @code{()}) (type: list-of-strings)
21472 Extra configuration values to append to the LightDM configuration file.
21478 @c %end of fragment
21479 @c %start of fragment
21481 @deftp {Data Type} lightdm-gtk-greeter-configuration
21482 Available @code{lightdm-gtk-greeter-configuration} fields are:
21485 @item @code{lightdm-gtk-greeter} (default: @code{lightdm-gtk-greeter}) (type: file-like)
21486 The lightdm-gtk-greeter package to use.
21488 @item @code{assets} @
21489 (default: @code{(adwaita-icon-theme gnome-themes-extrahicolor-icon-theme)}) @
21490 (type: list-of-file-likes)
21491 The list of packages complementing the greeter, such as package
21492 providing icon themes.
21494 @item @code{theme-name} (default: @code{"Adwaita"}) (type: string)
21495 The name of the theme to use.
21497 @item @code{icon-theme-name} (default: @code{"Adwaita"}) (type: string)
21498 The name of the icon theme to use.
21500 @item @code{cursor-theme-name} (default: @code{"Adwaita"}) (type: string)
21501 The name of the cursor theme to use.
21503 @item @code{cursor-theme-size} (default: @code{16}) (type: number)
21504 The size to use for the the cursor theme.
21506 @item @code{allow-debugging?} (type: maybe-boolean)
21507 Set to #t to enable debug log level.
21509 @item @code{background} (type: file-like)
21510 The background image to use.
21512 @item @code{at-spi-enabled?} (default: @code{#f}) (type: boolean)
21513 Enable accessibility support through the Assistive Technology Service
21514 Provider Interface (AT-SPI).
21516 @item @code{a11y-states} @
21517 (default: @code{(contrast font keyboard reader)}) (type: list-of-a11y-states)
21518 The accessibility features to enable, given as list of symbols.
21520 @item @code{reader} (type: maybe-file-like)
21521 The command to use to launch a screen reader.
21523 @item @code{extra-config} (default: @code{()}) (type: list-of-strings)
21524 Extra configuration values to append to the LightDM GTK Greeter
21525 configuration file.
21530 @c %end of fragment
21531 @c %start of fragment
21533 @deftp {Data Type} lightdm-seat-configuration
21534 Available @code{lightdm-seat-configuration} fields are:
21537 @item @code{name} (type: seat-name)
21538 The name of the seat. An asterisk (*) can be used in the name to apply
21539 the seat configuration to all the seat names it matches.
21541 @item @code{user-session} (type: maybe-string)
21542 The session to use by default. The session name must be provided as a
21543 lowercase string, such as @code{"gnome"}, @code{"ratpoison"}, etc.
21545 @item @code{type} (default: @code{local}) (type: seat-type)
21546 The type of the seat, either the @code{local} or @code{xremote} symbol.
21548 @item @code{autologin-user} (type: maybe-string)
21549 The username to automatically log in with by default.
21551 @item @code{greeter-session} @
21552 (default: @code{lightdm-gtk-greeter}) (type: greeter-session)
21553 The greeter session to use, specified as a symbol. Currently, only
21554 @code{lightdm-gtk-greeter} is supported.
21556 @item @code{xserver-command} (type: maybe-file-like)
21557 The Xorg server command to run.
21559 @item @code{session-wrapper} (type: file-like)
21560 The xinitrc session wrapper to use.
21562 @item @code{extra-config} (default: @code{()}) (type: list-of-strings)
21563 Extra configuration values to append to the seat configuration section.
21567 @c %end of fragment
21570 @cindex Xorg, configuration
21571 @deftp {Data Type} xorg-configuration
21572 This data type represents the configuration of the Xorg graphical
21573 display server. Note that there is no Xorg service; instead, the X
21574 server is started by a ``display manager'' such as GDM, SDDM, LightDM or
21575 SLiM@. Thus, the configuration of these display managers aggregates an
21576 @code{xorg-configuration} record.
21579 @item @code{modules} (default: @code{%default-xorg-modules})
21580 This is a list of @dfn{module packages} loaded by the Xorg
21581 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
21583 @item @code{fonts} (default: @code{%default-xorg-fonts})
21584 This is a list of font directories to add to the server's @dfn{font path}.
21586 @item @code{drivers} (default: @code{'()})
21587 This must be either the empty list, in which case Xorg chooses a graphics
21588 driver automatically, or a list of driver names that will be tried in this
21589 order---e.g., @code{("modesetting" "vesa")}.
21591 @item @code{resolutions} (default: @code{'()})
21592 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
21593 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
21596 @cindex keyboard layout, for Xorg
21597 @cindex keymap, for Xorg
21598 @item @code{keyboard-layout} (default: @code{#f})
21599 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
21600 English (``qwerty'') for a 105-key PC keyboard.
21602 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
21603 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
21604 information on how to specify the keyboard layout.
21606 @item @code{extra-config} (default: @code{'()})
21607 This is a list of strings or objects appended to the configuration file. It
21608 is used to pass extra text to be added verbatim to the configuration file.
21610 @item @code{server} (default: @code{xorg-server})
21611 This is the package providing the Xorg server.
21613 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
21614 This is the list of command-line arguments to pass to the X server. The
21615 default is @code{-nolisten tcp}.
21619 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
21620 [@var{login-manager-service-type}]
21621 Tell the log-in manager (of type @var{login-manager-service-type}) to use
21622 @var{config}, an @code{<xorg-configuration>} record.
21624 Since the Xorg configuration is embedded in the log-in manager's
21625 configuration---e.g., @code{gdm-configuration}---this procedure provides a
21626 shorthand to set the Xorg configuration.
21629 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
21630 Return a @code{startx} script in which the modules, fonts, etc. specified
21631 in @var{config}, are available. The result should be used in place of
21634 Usually the X server is started by a login manager.
21638 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
21639 Add @var{package}, a package for a screen locker or screen saver whose
21640 command is @var{program}, to the set of setuid programs and add a PAM entry
21641 for it. For example:
21644 (screen-locker-service xlockmore "xlock")
21647 makes the good ol' XlockMore usable.
21651 @node Printing Services
21652 @subsection Printing Services
21654 @cindex printer support with CUPS
21655 The @code{(gnu services cups)} module provides a Guix service definition
21656 for the CUPS printing service. To add printer support to a Guix
21657 system, add a @code{cups-service} to the operating system definition:
21659 @deffn {Scheme Variable} cups-service-type
21660 The service type for the CUPS print server. Its value should be a valid
21661 CUPS configuration (see below). To use the default settings, simply
21664 (service cups-service-type)
21668 The CUPS configuration controls the basic things about your CUPS
21669 installation: what interfaces it listens on, what to do if a print job
21670 fails, how much logging to do, and so on. To actually add a printer,
21671 you have to visit the @url{http://localhost:631} URL, or use a tool such
21672 as GNOME's printer configuration services. By default, configuring a
21673 CUPS service will generate a self-signed certificate if needed, for
21674 secure connections to the print server.
21676 Suppose you want to enable the Web interface of CUPS and also add
21677 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
21678 package and for HP printers @i{via} the @code{hplip-minimal} package.
21679 You can do that directly, like this (you need to use the
21680 @code{(gnu packages cups)} module):
21683 (service cups-service-type
21684 (cups-configuration
21685 (web-interface? #t)
21687 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
21691 If you wish to use the Qt5 based GUI which comes with the hplip
21692 package then it is suggested that you install the @code{hplip} package,
21693 either in your OS configuration file or as your user.
21696 The available configuration parameters follow. Each parameter
21697 definition is preceded by its type; for example, @samp{string-list foo}
21698 indicates that the @code{foo} parameter should be specified as a list of
21699 strings. There is also a way to specify the configuration as a string,
21700 if you have an old @code{cupsd.conf} file that you want to port over
21701 from some other system; see the end for more details.
21703 @c The following documentation was initially generated by
21704 @c (generate-documentation) in (gnu services cups). Manually maintained
21705 @c documentation is better, so we shouldn't hesitate to edit below as
21706 @c needed. However if the change you want to make to this documentation
21707 @c can be done in an automated way, it's probably easier to change
21708 @c (generate-documentation) than to make it below and have to deal with
21709 @c the churn as CUPS updates.
21712 Available @code{cups-configuration} fields are:
21714 @deftypevr {@code{cups-configuration} parameter} package cups
21718 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
21719 Drivers and other extensions to the CUPS package.
21722 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
21723 Configuration of where to write logs, what directories to use for print
21724 spools, and related privileged configuration parameters.
21726 Available @code{files-configuration} fields are:
21728 @deftypevr {@code{files-configuration} parameter} log-location access-log
21729 Defines the access log filename. Specifying a blank filename disables
21730 access log generation. The value @code{stderr} causes log entries to be
21731 sent to the standard error file when the scheduler is running in the
21732 foreground, or to the system log daemon when run in the background. The
21733 value @code{syslog} causes log entries to be sent to the system log
21734 daemon. The server name may be included in filenames using the string
21735 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
21737 Defaults to @samp{"/var/log/cups/access_log"}.
21740 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
21741 Where CUPS should cache data.
21743 Defaults to @samp{"/var/cache/cups"}.
21746 @deftypevr {@code{files-configuration} parameter} string config-file-perm
21747 Specifies the permissions for all configuration files that the scheduler
21750 Note that the permissions for the printers.conf file are currently
21751 masked to only allow access from the scheduler user (typically root).
21752 This is done because printer device URIs sometimes contain sensitive
21753 authentication information that should not be generally known on the
21754 system. There is no way to disable this security feature.
21756 Defaults to @samp{"0640"}.
21759 @deftypevr {@code{files-configuration} parameter} log-location error-log
21760 Defines the error log filename. Specifying a blank filename disables
21761 error log generation. The value @code{stderr} causes log entries to be
21762 sent to the standard error file when the scheduler is running in the
21763 foreground, or to the system log daemon when run in the background. The
21764 value @code{syslog} causes log entries to be sent to the system log
21765 daemon. The server name may be included in filenames using the string
21766 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
21768 Defaults to @samp{"/var/log/cups/error_log"}.
21771 @deftypevr {@code{files-configuration} parameter} string fatal-errors
21772 Specifies which errors are fatal, causing the scheduler to exit. The
21777 No errors are fatal.
21780 All of the errors below are fatal.
21783 Browsing initialization errors are fatal, for example failed connections
21784 to the DNS-SD daemon.
21787 Configuration file syntax errors are fatal.
21790 Listen or Port errors are fatal, except for IPv6 failures on the
21791 loopback or @code{any} addresses.
21794 Log file creation or write errors are fatal.
21797 Bad startup file permissions are fatal, for example shared TLS
21798 certificate and key files with world-read permissions.
21801 Defaults to @samp{"all -browse"}.
21804 @deftypevr {@code{files-configuration} parameter} boolean file-device?
21805 Specifies whether the file pseudo-device can be used for new printer
21806 queues. The URI @uref{file:///dev/null} is always allowed.
21808 Defaults to @samp{#f}.
21811 @deftypevr {@code{files-configuration} parameter} string group
21812 Specifies the group name or ID that will be used when executing external
21815 Defaults to @samp{"lp"}.
21818 @deftypevr {@code{files-configuration} parameter} string log-file-group
21819 Specifies the group name or ID that will be used for log files.
21821 Defaults to @samp{"lpadmin"}.
21824 @deftypevr {@code{files-configuration} parameter} string log-file-perm
21825 Specifies the permissions for all log files that the scheduler writes.
21827 Defaults to @samp{"0644"}.
21830 @deftypevr {@code{files-configuration} parameter} log-location page-log
21831 Defines the page log filename. Specifying a blank filename disables
21832 page log generation. The value @code{stderr} causes log entries to be
21833 sent to the standard error file when the scheduler is running in the
21834 foreground, or to the system log daemon when run in the background. The
21835 value @code{syslog} causes log entries to be sent to the system log
21836 daemon. The server name may be included in filenames using the string
21837 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
21839 Defaults to @samp{"/var/log/cups/page_log"}.
21842 @deftypevr {@code{files-configuration} parameter} string remote-root
21843 Specifies the username that is associated with unauthenticated accesses
21844 by clients claiming to be the root user. The default is @code{remroot}.
21846 Defaults to @samp{"remroot"}.
21849 @deftypevr {@code{files-configuration} parameter} file-name request-root
21850 Specifies the directory that contains print jobs and other HTTP request
21853 Defaults to @samp{"/var/spool/cups"}.
21856 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
21857 Specifies the level of security sandboxing that is applied to print
21858 filters, backends, and other child processes of the scheduler; either
21859 @code{relaxed} or @code{strict}. This directive is currently only
21860 used/supported on macOS.
21862 Defaults to @samp{strict}.
21865 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
21866 Specifies the location of TLS certificates and private keys. CUPS will
21867 look for public and private keys in this directory: @file{.crt} files
21868 for PEM-encoded certificates and corresponding @file{.key} files for
21869 PEM-encoded private keys.
21871 Defaults to @samp{"/etc/cups/ssl"}.
21874 @deftypevr {@code{files-configuration} parameter} file-name server-root
21875 Specifies the directory containing the server configuration files.
21877 Defaults to @samp{"/etc/cups"}.
21880 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
21881 Specifies whether the scheduler calls fsync(2) after writing
21882 configuration or state files.
21884 Defaults to @samp{#f}.
21887 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
21888 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
21891 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
21892 Specifies the directory where temporary files are stored.
21894 Defaults to @samp{"/var/spool/cups/tmp"}.
21897 @deftypevr {@code{files-configuration} parameter} string user
21898 Specifies the user name or ID that is used when running external
21901 Defaults to @samp{"lp"}.
21904 @deftypevr {@code{files-configuration} parameter} string set-env
21905 Set the specified environment variable to be passed to child processes.
21907 Defaults to @samp{"variable value"}.
21911 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
21912 Specifies the logging level for the AccessLog file. The @code{config}
21913 level logs when printers and classes are added, deleted, or modified and
21914 when configuration files are accessed or updated. The @code{actions}
21915 level logs when print jobs are submitted, held, released, modified, or
21916 canceled, and any of the conditions for @code{config}. The @code{all}
21917 level logs all requests.
21919 Defaults to @samp{actions}.
21922 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
21923 Specifies whether to purge job history data automatically when it is no
21924 longer required for quotas.
21926 Defaults to @samp{#f}.
21929 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
21930 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
21931 For example, @samp{"_cups" "_print"} will tell network clients that both
21932 CUPS sharing and IPP Everywhere are supported.
21934 Defaults to @samp{"_cups"}.
21937 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
21938 Specifies which protocols to use for local printer sharing.
21940 Defaults to @samp{dnssd}.
21943 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
21944 Specifies whether the CUPS web interface is advertised.
21946 Defaults to @samp{#f}.
21949 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
21950 Specifies whether shared printers are advertised.
21952 Defaults to @samp{#f}.
21955 @deftypevr {@code{cups-configuration} parameter} string classification
21956 Specifies the security classification of the server. Any valid banner
21957 name can be used, including @samp{"classified"}, @samp{"confidential"},
21958 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
21959 banner can be omitted to disable secure printing functions.
21961 Defaults to @samp{""}.
21964 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
21965 Specifies whether users may override the classification (cover page) of
21966 individual print jobs using the @code{job-sheets} option.
21968 Defaults to @samp{#f}.
21971 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
21972 Specifies the default type of authentication to use.
21974 Defaults to @samp{Basic}.
21977 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
21978 Specifies whether encryption will be used for authenticated requests.
21980 Defaults to @samp{Required}.
21983 @deftypevr {@code{cups-configuration} parameter} string default-language
21984 Specifies the default language to use for text and web content.
21986 Defaults to @samp{"en"}.
21989 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
21990 Specifies the default paper size for new print queues. @samp{"Auto"}
21991 uses a locale-specific default, while @samp{"None"} specifies there is
21992 no default paper size. Specific size names are typically
21993 @samp{"Letter"} or @samp{"A4"}.
21995 Defaults to @samp{"Auto"}.
21998 @deftypevr {@code{cups-configuration} parameter} string default-policy
21999 Specifies the default access policy to use.
22001 Defaults to @samp{"default"}.
22004 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
22005 Specifies whether local printers are shared by default.
22007 Defaults to @samp{#t}.
22010 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
22011 Specifies the delay for updating of configuration and state files, in
22012 seconds. A value of 0 causes the update to happen as soon as possible,
22013 typically within a few milliseconds.
22015 Defaults to @samp{30}.
22018 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
22019 Specifies what to do when an error occurs. Possible values are
22020 @code{abort-job}, which will discard the failed print job;
22021 @code{retry-job}, which will retry the job at a later time;
22022 @code{retry-current-job}, which retries the failed job immediately; and
22023 @code{stop-printer}, which stops the printer.
22025 Defaults to @samp{stop-printer}.
22028 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
22029 Specifies the maximum cost of filters that are run concurrently, which
22030 can be used to minimize disk, memory, and CPU resource problems. A
22031 limit of 0 disables filter limiting. An average print to a
22032 non-PostScript printer needs a filter limit of about 200. A PostScript
22033 printer needs about half that (100). Setting the limit below these
22034 thresholds will effectively limit the scheduler to printing a single job
22037 Defaults to @samp{0}.
22040 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
22041 Specifies the scheduling priority of filters that are run to print a
22042 job. The nice value ranges from 0, the highest priority, to 19, the
22045 Defaults to @samp{0}.
22048 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
22049 Specifies whether to do reverse lookups on connecting clients. The
22050 @code{double} setting causes @code{cupsd} to verify that the hostname
22051 resolved from the address matches one of the addresses returned for that
22052 hostname. Double lookups also prevent clients with unregistered
22053 addresses from connecting to your server. Only set this option to
22054 @code{#t} or @code{double} if absolutely required.
22056 Defaults to @samp{#f}.
22059 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
22060 Specifies the number of seconds to wait before killing the filters and
22061 backend associated with a canceled or held job.
22063 Defaults to @samp{30}.
22066 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
22067 Specifies the interval between retries of jobs in seconds. This is
22068 typically used for fax queues but can also be used with normal print
22069 queues whose error policy is @code{retry-job} or
22070 @code{retry-current-job}.
22072 Defaults to @samp{30}.
22075 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
22076 Specifies the number of retries that are done for jobs. This is
22077 typically used for fax queues but can also be used with normal print
22078 queues whose error policy is @code{retry-job} or
22079 @code{retry-current-job}.
22081 Defaults to @samp{5}.
22084 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
22085 Specifies whether to support HTTP keep-alive connections.
22087 Defaults to @samp{#t}.
22090 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
22091 Specifies the maximum size of print files, IPP requests, and HTML form
22092 data. A limit of 0 disables the limit check.
22094 Defaults to @samp{0}.
22097 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
22098 Listens on the specified interfaces for connections. Valid values are
22099 of the form @var{address}:@var{port}, where @var{address} is either an
22100 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
22101 indicate all addresses. Values can also be file names of local UNIX
22102 domain sockets. The Listen directive is similar to the Port directive
22103 but allows you to restrict access to specific interfaces or networks.
22106 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
22107 Specifies the number of pending connections that will be allowed. This
22108 normally only affects very busy servers that have reached the MaxClients
22109 limit, but can also be triggered by large numbers of simultaneous
22110 connections. When the limit is reached, the operating system will
22111 refuse additional connections until the scheduler can accept the pending
22114 Defaults to @samp{128}.
22117 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
22118 Specifies a set of additional access controls.
22120 Available @code{location-access-controls} fields are:
22122 @deftypevr {@code{location-access-controls} parameter} file-name path
22123 Specifies the URI path to which the access control applies.
22126 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
22127 Access controls for all access to this path, in the same format as the
22128 @code{access-controls} of @code{operation-access-control}.
22130 Defaults to @samp{()}.
22133 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
22134 Access controls for method-specific access to this path.
22136 Defaults to @samp{()}.
22138 Available @code{method-access-controls} fields are:
22140 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
22141 If @code{#t}, apply access controls to all methods except the listed
22142 methods. Otherwise apply to only the listed methods.
22144 Defaults to @samp{#f}.
22147 @deftypevr {@code{method-access-controls} parameter} method-list methods
22148 Methods to which this access control applies.
22150 Defaults to @samp{()}.
22153 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
22154 Access control directives, as a list of strings. Each string should be
22155 one directive, such as @samp{"Order allow,deny"}.
22157 Defaults to @samp{()}.
22162 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
22163 Specifies the number of debugging messages that are retained for logging
22164 if an error occurs in a print job. Debug messages are logged regardless
22165 of the LogLevel setting.
22167 Defaults to @samp{100}.
22170 @deftypevr {@code{cups-configuration} parameter} log-level log-level
22171 Specifies the level of logging for the ErrorLog file. The value
22172 @code{none} stops all logging while @code{debug2} logs everything.
22174 Defaults to @samp{info}.
22177 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
22178 Specifies the format of the date and time in the log files. The value
22179 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
22181 Defaults to @samp{standard}.
22184 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
22185 Specifies the maximum number of simultaneous clients that are allowed by
22188 Defaults to @samp{100}.
22191 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
22192 Specifies the maximum number of simultaneous clients that are allowed
22193 from a single address.
22195 Defaults to @samp{100}.
22198 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
22199 Specifies the maximum number of copies that a user can print of each
22202 Defaults to @samp{9999}.
22205 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
22206 Specifies the maximum time a job may remain in the @code{indefinite}
22207 hold state before it is canceled. A value of 0 disables cancellation of
22210 Defaults to @samp{0}.
22213 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
22214 Specifies the maximum number of simultaneous jobs that are allowed. Set
22215 to 0 to allow an unlimited number of jobs.
22217 Defaults to @samp{500}.
22220 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
22221 Specifies the maximum number of simultaneous jobs that are allowed per
22222 printer. A value of 0 allows up to MaxJobs jobs per printer.
22224 Defaults to @samp{0}.
22227 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
22228 Specifies the maximum number of simultaneous jobs that are allowed per
22229 user. A value of 0 allows up to MaxJobs jobs per user.
22231 Defaults to @samp{0}.
22234 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
22235 Specifies the maximum time a job may take to print before it is
22236 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
22238 Defaults to @samp{10800}.
22241 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
22242 Specifies the maximum size of the log files before they are rotated, in
22243 bytes. The value 0 disables log rotation.
22245 Defaults to @samp{1048576}.
22248 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
22249 Specifies the maximum amount of time to allow between files in a
22250 multiple file print job, in seconds.
22252 Defaults to @samp{900}.
22255 @deftypevr {@code{cups-configuration} parameter} string page-log-format
22256 Specifies the format of PageLog lines. Sequences beginning with percent
22257 (@samp{%}) characters are replaced with the corresponding information,
22258 while all other characters are copied literally. The following percent
22259 sequences are recognized:
22263 insert a single percent character
22266 insert the value of the specified IPP attribute
22269 insert the number of copies for the current page
22272 insert the current page number
22275 insert the current date and time in common log format
22281 insert the printer name
22284 insert the username
22287 A value of the empty string disables page logging. The string @code{%p
22288 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
22289 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
22292 Defaults to @samp{""}.
22295 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
22296 Passes the specified environment variable(s) to child processes; a list
22299 Defaults to @samp{()}.
22302 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
22303 Specifies named access control policies.
22305 Available @code{policy-configuration} fields are:
22307 @deftypevr {@code{policy-configuration} parameter} string name
22308 Name of the policy.
22311 @deftypevr {@code{policy-configuration} parameter} string job-private-access
22312 Specifies an access list for a job's private values. @code{@@ACL} maps
22313 to the printer's requesting-user-name-allowed or
22314 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
22315 owner. @code{@@SYSTEM} maps to the groups listed for the
22316 @code{system-group} field of the @code{files-configuration},
22317 which is reified into the @code{cups-files.conf(5)} file. Other
22318 possible elements of the access list include specific user names, and
22319 @code{@@@var{group}} to indicate members of a specific group. The
22320 access list may also be simply @code{all} or @code{default}.
22322 Defaults to @samp{"@@OWNER @@SYSTEM"}.
22325 @deftypevr {@code{policy-configuration} parameter} string job-private-values
22326 Specifies the list of job values to make private, or @code{all},
22327 @code{default}, or @code{none}.
22329 Defaults to @samp{"job-name job-originating-host-name
22330 job-originating-user-name phone"}.
22333 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
22334 Specifies an access list for a subscription's private values.
22335 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
22336 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
22337 owner. @code{@@SYSTEM} maps to the groups listed for the
22338 @code{system-group} field of the @code{files-configuration},
22339 which is reified into the @code{cups-files.conf(5)} file. Other
22340 possible elements of the access list include specific user names, and
22341 @code{@@@var{group}} to indicate members of a specific group. The
22342 access list may also be simply @code{all} or @code{default}.
22344 Defaults to @samp{"@@OWNER @@SYSTEM"}.
22347 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
22348 Specifies the list of job values to make private, or @code{all},
22349 @code{default}, or @code{none}.
22351 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
22352 notify-subscriber-user-name notify-user-data"}.
22355 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
22356 Access control by IPP operation.
22358 Defaults to @samp{()}.
22362 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
22363 Specifies whether job files (documents) are preserved after a job is
22364 printed. If a numeric value is specified, job files are preserved for
22365 the indicated number of seconds after printing. Otherwise a boolean
22366 value applies indefinitely.
22368 Defaults to @samp{86400}.
22371 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
22372 Specifies whether the job history is preserved after a job is printed.
22373 If a numeric value is specified, the job history is preserved for the
22374 indicated number of seconds after printing. If @code{#t}, the job
22375 history is preserved until the MaxJobs limit is reached.
22377 Defaults to @samp{#t}.
22380 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
22381 Specifies the amount of time to wait for job completion before
22382 restarting the scheduler.
22384 Defaults to @samp{30}.
22387 @deftypevr {@code{cups-configuration} parameter} string rip-cache
22388 Specifies the maximum amount of memory to use when converting documents
22389 into bitmaps for a printer.
22391 Defaults to @samp{"128m"}.
22394 @deftypevr {@code{cups-configuration} parameter} string server-admin
22395 Specifies the email address of the server administrator.
22397 Defaults to @samp{"root@@localhost.localdomain"}.
22400 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
22401 The ServerAlias directive is used for HTTP Host header validation when
22402 clients connect to the scheduler from external interfaces. Using the
22403 special name @code{*} can expose your system to known browser-based DNS
22404 rebinding attacks, even when accessing sites through a firewall. If the
22405 auto-discovery of alternate names does not work, we recommend listing
22406 each alternate name with a ServerAlias directive instead of using
22409 Defaults to @samp{*}.
22412 @deftypevr {@code{cups-configuration} parameter} string server-name
22413 Specifies the fully-qualified host name of the server.
22415 Defaults to @samp{"localhost"}.
22418 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
22419 Specifies what information is included in the Server header of HTTP
22420 responses. @code{None} disables the Server header. @code{ProductOnly}
22421 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
22422 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
22423 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
22424 the output of the @code{uname} command. @code{Full} reports @code{CUPS
22425 2.0.0 (@var{uname}) IPP/2.0}.
22427 Defaults to @samp{Minimal}.
22430 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
22431 Listens on the specified interfaces for encrypted connections. Valid
22432 values are of the form @var{address}:@var{port}, where @var{address} is
22433 either an IPv6 address enclosed in brackets, an IPv4 address, or
22434 @code{*} to indicate all addresses.
22436 Defaults to @samp{()}.
22439 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
22440 Sets encryption options. By default, CUPS only supports encryption
22441 using TLS v1.0 or higher using known secure cipher suites. Security is
22442 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
22443 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
22444 suites, which are required for some older clients. The @code{AllowSSL3} option
22445 enables SSL v3.0, which is required for some older clients that do not support
22446 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
22447 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
22448 protocol version to TLS v1.1.
22450 Defaults to @samp{()}.
22453 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
22454 Specifies whether the scheduler requires clients to strictly adhere to
22455 the IPP specifications.
22457 Defaults to @samp{#f}.
22460 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
22461 Specifies the HTTP request timeout, in seconds.
22463 Defaults to @samp{900}.
22467 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
22468 Specifies whether the web interface is enabled.
22470 Defaults to @samp{#f}.
22473 At this point you're probably thinking ``oh dear, Guix manual, I like
22474 you but you can stop already with the configuration options''. Indeed.
22475 However, one more point: it could be that you have an existing
22476 @code{cupsd.conf} that you want to use. In that case, you can pass an
22477 @code{opaque-cups-configuration} as the configuration of a
22478 @code{cups-service-type}.
22480 Available @code{opaque-cups-configuration} fields are:
22482 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
22486 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
22487 The contents of the @code{cupsd.conf}, as a string.
22490 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
22491 The contents of the @code{cups-files.conf} file, as a string.
22494 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
22495 strings of the same name, you could instantiate a CUPS service like
22499 (service cups-service-type
22500 (opaque-cups-configuration
22501 (cupsd.conf cupsd.conf)
22502 (cups-files.conf cups-files.conf)))
22506 @node Desktop Services
22507 @subsection Desktop Services
22509 The @code{(gnu services desktop)} module provides services that are
22510 usually useful in the context of a ``desktop'' setup---that is, on a
22511 machine running a graphical display server, possibly with graphical user
22512 interfaces, etc. It also defines services that provide specific desktop
22513 environments like GNOME, Xfce or MATE.
22515 To simplify things, the module defines a variable containing the set of
22516 services that users typically expect on a machine with a graphical
22517 environment and networking:
22519 @defvr {Scheme Variable} %desktop-services
22520 This is a list of services that builds upon @code{%base-services} and
22521 adds or adjusts services for a typical ``desktop'' setup.
22523 In particular, it adds a graphical login manager (@pxref{X Window,
22524 @code{gdm-service-type}}), screen lockers, a network management tool
22525 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
22526 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
22527 energy and color management services, the @code{elogind} login and seat
22528 manager, the Polkit privilege service, the GeoClue location service, the
22529 AccountsService daemon that allows authorized users change system passwords,
22530 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
22531 name service switch service configured to be able to use @code{nss-mdns}
22532 (@pxref{Name Service Switch, mDNS}).
22535 The @code{%desktop-services} variable can be used as the @code{services}
22536 field of an @code{operating-system} declaration (@pxref{operating-system
22537 Reference, @code{services}}).
22539 Additionally, the @code{gnome-desktop-service-type},
22540 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
22541 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
22542 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
22543 ``add GNOME'' means that system-level services like the backlight adjustment
22544 helpers and the power management utilities are added to the system, extending
22545 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
22546 elevated privileges on a limited number of special-purpose system interfaces.
22547 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
22548 the GNOME metapackage to the system profile. Likewise, adding the Xfce
22549 service not only adds the @code{xfce} metapackage to the system profile, but
22550 it also gives the Thunar file manager the ability to open a ``root-mode'' file
22551 management window, if the user authenticates using the administrator's
22552 password via the standard polkit graphical interface. To ``add MATE'' means
22553 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
22554 to operate with elevated privileges on a limited number of special-purpose
22555 system interfaces. Additionally, adding a service of type
22556 @code{mate-desktop-service-type} adds the MATE metapackage to the system
22557 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
22558 appropriately, and several of Enlightenment's binaries are set as setuid,
22559 allowing Enlightenment's screen locker and other functionality to work as
22562 The desktop environments in Guix use the Xorg display server by
22563 default. If you'd like to use the newer display server protocol
22564 called Wayland, you need to enable Wayland support in GDM
22565 (@pxref{wayland-gdm}). Another solution is to use the
22566 @code{sddm-service} instead of GDM as the graphical login manager.
22567 You should then select the ``GNOME (Wayland)'' session in SDDM@.
22568 Alternatively you can also try starting GNOME on Wayland manually from a
22569 TTY with the command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
22570 gnome-session``. Currently only GNOME has support for Wayland.
22572 @defvr {Scheme Variable} gnome-desktop-service-type
22573 This is the type of the service that adds the @uref{https://www.gnome.org,
22574 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
22575 object (see below).
22577 This service adds the @code{gnome} package to the system profile, and extends
22578 polkit with the actions from @code{gnome-settings-daemon}.
22581 @deftp {Data Type} gnome-desktop-configuration
22582 Configuration record for the GNOME desktop environment.
22585 @item @code{gnome} (default: @code{gnome})
22586 The GNOME package to use.
22590 @defvr {Scheme Variable} xfce-desktop-service-type
22591 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
22592 desktop environment. Its value is an @code{xfce-desktop-configuration} object
22595 This service adds the @code{xfce} package to the system profile, and
22596 extends polkit with the ability for @code{thunar} to manipulate the file
22597 system as root from within a user session, after the user has authenticated
22598 with the administrator's password.
22600 Note that @code{xfce4-panel} and its plugin packages should be installed in
22601 the same profile to ensure compatibility. When using this service, you should
22602 add extra plugins (@code{xfce4-whiskermenu-plugin},
22603 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
22604 @code{operating-system}.
22607 @deftp {Data Type} xfce-desktop-configuration
22608 Configuration record for the Xfce desktop environment.
22611 @item @code{xfce} (default: @code{xfce})
22612 The Xfce package to use.
22616 @deffn {Scheme Variable} mate-desktop-service-type
22617 This is the type of the service that runs the @uref{https://mate-desktop.org/,
22618 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
22619 object (see below).
22621 This service adds the @code{mate} package to the system
22622 profile, and extends polkit with the actions from
22623 @code{mate-settings-daemon}.
22626 @deftp {Data Type} mate-desktop-configuration
22627 Configuration record for the MATE desktop environment.
22630 @item @code{mate} (default: @code{mate})
22631 The MATE package to use.
22635 @deffn {Scheme Variable} lxqt-desktop-service-type
22636 This is the type of the service that runs the @uref{https://lxqt-project.org,
22637 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
22638 object (see below).
22640 This service adds the @code{lxqt} package to the system
22644 @deftp {Data Type} lxqt-desktop-configuration
22645 Configuration record for the LXQt desktop environment.
22648 @item @code{lxqt} (default: @code{lxqt})
22649 The LXQT package to use.
22653 @deffn {Scheme Variable} enlightenment-desktop-service-type
22654 Return a service that adds the @code{enlightenment} package to the system
22655 profile, and extends dbus with actions from @code{efl}.
22658 @deftp {Data Type} enlightenment-desktop-service-configuration
22660 @item @code{enlightenment} (default: @code{enlightenment})
22661 The enlightenment package to use.
22665 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
22666 the default @code{%desktop-services} variable doesn't include any of
22667 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
22668 @code{%desktop-services} in the @code{services} field of your
22669 @code{operating-system}:
22672 (use-modules (gnu))
22673 (use-service-modules desktop)
22676 ;; cons* adds items to the list given as its last argument.
22677 (services (cons* (service gnome-desktop-service-type)
22678 (service xfce-desktop-service)
22679 %desktop-services))
22683 These desktop environments will then be available as options in the
22684 graphical login window.
22686 The actual service definitions included in @code{%desktop-services} and
22687 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
22688 are described below.
22690 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()] @
22692 Return a service that runs the ``system bus'', using @var{dbus}, with
22693 support for @var{services}. When @var{verbose?} is true, it causes the
22694 @samp{DBUS_VERBOSE} environment variable to be set to @samp{1}; a
22695 verbose-enabled D-Bus package such as @code{dbus-verbose} should be
22696 provided as @var{dbus} in this scenario. The verbose output is logged
22697 to @file{/var/log/dbus-daemon.log}.
22699 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
22700 facility. Its system bus is used to allow system services to communicate
22701 and to be notified of system-wide events.
22703 @var{services} must be a list of packages that provide an
22704 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
22705 and policy files. For example, to allow avahi-daemon to use the system bus,
22706 @var{services} must be equal to @code{(list avahi)}.
22709 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
22710 Return a service that runs the @code{elogind} login and
22711 seat management daemon. @uref{https://github.com/elogind/elogind,
22712 Elogind} exposes a D-Bus interface that can be used to know which users
22713 are logged in, know what kind of sessions they have open, suspend the
22714 system, inhibit system suspend, reboot the system, and other tasks.
22716 Elogind handles most system-level power events for a computer, for
22717 example suspending the system when a lid is closed, or shutting it down
22718 when the power button is pressed.
22720 The @var{config} keyword argument specifies the configuration for
22721 elogind, and should be the result of an @code{(elogind-configuration
22722 (@var{parameter} @var{value})...)} invocation. Available parameters and
22723 their default values are:
22726 @item kill-user-processes?
22728 @item kill-only-users
22730 @item kill-exclude-users
22732 @item inhibit-delay-max-seconds
22734 @item handle-power-key
22736 @item handle-suspend-key
22738 @item handle-hibernate-key
22740 @item handle-lid-switch
22742 @item handle-lid-switch-docked
22744 @item handle-lid-switch-external-power
22745 @code{*unspecified*}
22746 @item power-key-ignore-inhibited?
22748 @item suspend-key-ignore-inhibited?
22750 @item hibernate-key-ignore-inhibited?
22752 @item lid-switch-ignore-inhibited?
22754 @item holdoff-timeout-seconds
22758 @item idle-action-seconds
22760 @item runtime-directory-size-percent
22762 @item runtime-directory-size
22766 @item suspend-state
22767 @code{("mem" "standby" "freeze")}
22770 @item hibernate-state
22772 @item hibernate-mode
22773 @code{("platform" "shutdown")}
22774 @item hybrid-sleep-state
22776 @item hybrid-sleep-mode
22777 @code{("suspend" "platform" "shutdown")}
22781 @deffn {Scheme Procedure} accountsservice-service @
22782 [#:accountsservice @var{accountsservice}]
22783 Return a service that runs AccountsService, a system service that can
22784 list available accounts, change their passwords, and so on.
22785 AccountsService integrates with PolicyKit to enable unprivileged users
22786 to acquire the capability to modify their system configuration.
22787 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
22788 accountsservice web site} for more information.
22790 The @var{accountsservice} keyword argument is the @code{accountsservice}
22791 package to expose as a service.
22794 @deffn {Scheme Procedure} polkit-service @
22795 [#:polkit @var{polkit}]
22796 Return a service that runs the
22797 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
22798 management service}, which allows system administrators to grant access to
22799 privileged operations in a structured way. By querying the Polkit service, a
22800 privileged system component can know when it should grant additional
22801 capabilities to ordinary users. For example, an ordinary user can be granted
22802 the capability to suspend the system if the user is logged in locally.
22805 @defvr {Scheme Variable} polkit-wheel-service
22806 Service that adds the @code{wheel} group as admins to the Polkit
22807 service. This makes it so that users in the @code{wheel} group are queried
22808 for their own passwords when performing administrative actions instead of
22809 @code{root}'s, similar to the behaviour used by @code{sudo}.
22812 @defvr {Scheme Variable} upower-service-type
22813 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
22814 system-wide monitor for power consumption and battery levels, with the given
22815 configuration settings.
22817 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
22818 notably used by GNOME.
22821 @deftp {Data Type} upower-configuration
22822 Data type representation the configuration for UPower.
22826 @item @code{upower} (default: @var{upower})
22827 Package to use for @code{upower}.
22829 @item @code{watts-up-pro?} (default: @code{#f})
22830 Enable the Watts Up Pro device.
22832 @item @code{poll-batteries?} (default: @code{#t})
22833 Enable polling the kernel for battery level changes.
22835 @item @code{ignore-lid?} (default: @code{#f})
22836 Ignore the lid state, this can be useful if it's incorrect on a device.
22838 @item @code{use-percentage-for-policy?} (default: @code{#t})
22839 Whether a to use a policy based on battery percentage rather than on
22840 estimated time left. A policy based on battery percentage is usually
22843 @item @code{percentage-low} (default: @code{20})
22844 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
22845 at which the battery is considered low.
22847 @item @code{percentage-critical} (default: @code{5})
22848 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
22849 at which the battery is considered critical.
22851 @item @code{percentage-action} (default: @code{2})
22852 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
22853 at which action will be taken.
22855 @item @code{time-low} (default: @code{1200})
22856 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
22857 seconds at which the battery is considered low.
22859 @item @code{time-critical} (default: @code{300})
22860 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
22861 seconds at which the battery is considered critical.
22863 @item @code{time-action} (default: @code{120})
22864 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
22865 seconds at which action will be taken.
22867 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
22868 The action taken when @code{percentage-action} or @code{time-action} is
22869 reached (depending on the configuration of @code{use-percentage-for-policy?}).
22871 Possible values are:
22881 @code{'hybrid-sleep}.
22887 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
22888 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
22889 UDisks}, a @dfn{disk management} daemon that provides user interfaces
22890 with notifications and ways to mount/unmount disks. Programs that talk
22891 to UDisks include the @command{udisksctl} command, part of UDisks, and
22892 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
22893 it will only be able to use the file-system utilities installed in the
22894 system profile. For example if you want to be able to mount NTFS
22895 file-systems in read and write fashion, you'll need to have
22896 @code{ntfs-3g} installed system-wide.
22899 @deffn {Scheme Variable} colord-service-type
22900 This is the type of the service that runs @command{colord}, a system
22901 service with a D-Bus
22902 interface to manage the color profiles of input and output devices such as
22903 screens and scanners. It is notably used by the GNOME Color Manager graphical
22904 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
22905 site} for more information.
22908 @cindex scanner access
22909 @defvr {Scheme Variable} sane-service-type
22910 This service provides access to scanners @i{via}
22911 @uref{http://www.sane-project.org, SANE} by installing the necessary
22912 udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
22913 Services}) and relies by default on @code{sane-backends-minimal} package
22914 (see below) for hardware support.
22917 @defvr {Scheme Variable} sane-backends-minimal
22918 The default package which the @code{sane-service-type} installs. It
22919 supports many recent scanners.
22922 @defvr {Scheme Variable} sane-backends
22923 This package includes support for all scanners that
22924 @code{sane-backends-minimal} supports, plus older Hewlett-Packard
22925 scanners supported by @code{hplip} package. In order to use this on
22926 a system which relies on @code{%desktop-services}, you may use
22927 @code{modify-services} (@pxref{Service Reference,
22928 @code{modify-services}}) as illustrated below:
22931 (use-modules (gnu))
22932 (use-service-modules
22935 (use-package-modules
22939 (define %my-desktop-services
22940 ;; List of desktop services that supports a broader range of scanners.
22941 (modify-services %desktop-services
22942 (sane-service-type _ => sane-backends)))
22946 (services %my-desktop-services))
22950 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
22951 Return a configuration allowing an application to access GeoClue
22952 location data. @var{name} is the Desktop ID of the application, without
22953 the @code{.desktop} part. If @var{allowed?} is true, the application
22954 will have access to location information by default. The boolean
22955 @var{system?} value indicates whether an application is a system component
22956 or not. Finally @var{users} is a list of UIDs of all users for which
22957 this application is allowed location info access. An empty users list
22958 means that all users are allowed.
22961 @defvr {Scheme Variable} %standard-geoclue-applications
22962 The standard list of well-known GeoClue application configurations,
22963 granting authority to the GNOME date-and-time utility to ask for the
22964 current location in order to set the time zone, and allowing the
22965 IceCat and Epiphany web browsers to request location information.
22966 IceCat and Epiphany both query the user before allowing a web page to
22967 know the user's location.
22970 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
22971 [#:whitelist '()] @
22972 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
22973 [#:submit-data? #f]
22974 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
22975 [#:submission-nick "geoclue"] @
22976 [#:applications %standard-geoclue-applications]
22977 Return a service that runs the GeoClue location service. This service
22978 provides a D-Bus interface to allow applications to request access to a
22979 user's physical location, and optionally to add information to online
22980 location databases. See
22981 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
22982 web site} for more information.
22985 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
22986 [@w{#:auto-enable? #f}]
22987 Return a service that runs the @command{bluetoothd} daemon, which
22988 manages all the Bluetooth devices and provides a number of D-Bus
22989 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
22990 powered automatically at boot, which can be useful when using a
22991 bluetooth keyboard or mouse.
22993 Users need to be in the @code{lp} group to access the D-Bus service.
22996 @deffn {Scheme Variable} bluetooth-service-type
22997 This is the type for the @uref{https://bluez.org/, Linux Bluetooth Protocol
22998 Stack} (BlueZ) system, which generates the @file{/etc/bluetooth/main.conf}
22999 configuration file. The value for this type is a @command{bluetooth-configuration}
23000 record as in this example:
23003 (service bluetooth-service-type)
23006 See below for details about @code{bluetooth-configuration}.
23009 @deftp {Data Type} bluetooth-configuration
23010 Data type representing the configuration for @code{bluetooth-service}.
23013 @item @code{bluez} (default: @code{bluez})
23014 @code{bluez} package to use.
23016 @item @code{name} (default: @code{"BlueZ"})
23017 Default adapter name.
23019 @item @code{class} (default: @code{#x000000})
23020 Default device class. Only the major and minor device class bits are considered.
23022 @item @code{discoverable-timeout} (default: @code{180})
23023 How long to stay in discoverable mode before going back to non-discoverable. The
23024 value is in seconds.
23026 @item @code{always-pairable?} (default: @code{#f})
23027 Always allow pairing even if there are no agents registered.
23029 @item @code{pairable-timeout} (default: @code{0})
23030 How long to stay in pairable mode before going back to non-discoverable. The
23031 value is in seconds.
23033 @item @code{device-id} (default: @code{#f})
23034 Use vendor id source (assigner), vendor, product and version information for
23035 DID profile support. The values are separated by ":" and @var{assigner}, @var{VID},
23036 @var{PID} and @var{version}.
23038 Possible values are:
23042 @code{#f} to disable it,
23045 @code{"assigner:1234:5678:abcd"}, where @var{assigner} is either @code{usb} (default)
23046 or @code{bluetooth}.
23050 @item @code{reverse-service-discovery?} (default: @code{#t})
23051 Do reverse service discovery for previously unknown devices that connect to
23052 us. For BR/EDR this option is really only needed for qualification since the
23053 BITE tester doesn't like us doing reverse SDP for some test cases, for LE
23054 this disables the GATT client functionally so it can be used in system which
23055 can only operate as peripheral.
23057 @item @code{name-resolving?} (default: @code{#t})
23058 Enable name resolving after inquiry. Set it to @code{#f} if you don't need
23059 remote devices name and want shorter discovery cycle.
23061 @item @code{debug-keys?} (default: @code{#f})
23062 Enable runtime persistency of debug link keys. Default is false which makes
23063 debug link keys valid only for the duration of the connection that they were
23066 @item @code{controller-mode} (default: @code{'dual})
23067 Restricts all controllers to the specified transport. @code{'dual} means both
23068 BR/EDR and LE are enabled (if supported by the hardware).
23070 Possible values are:
23084 @item @code{multi-profile} (default: @code{'off})
23085 Enables Multi Profile Specification support. This allows to specify if system
23086 supports only Multiple Profiles Single Device (MPSD) configuration or both
23087 Multiple Profiles Single Device (MPSD) and Multiple Profiles Multiple Devices
23088 (MPMD) configurations.
23090 Possible values are:
23104 @item @code{fast-connectable?} (default: @code{#f})
23105 Permanently enables the Fast Connectable setting for adapters that support
23106 it. When enabled other devices can connect faster to us, however the
23107 tradeoff is increased power consumptions. This feature will fully work only
23108 on kernel version 4.1 and newer.
23110 @item @code{privacy} (default: @code{'off})
23111 Default privacy settings.
23115 @code{'off}: Disable local privacy
23118 @code{'network/on}: A device will only accept advertising packets from peer
23119 devices that contain private addresses. It may not be compatible with some
23120 legacy devices since it requires the use of RPA(s) all the time
23123 @code{'device}: A device in device privacy mode is only concerned about the
23124 privacy of the device and will accept advertising packets from peer devices
23125 that contain their Identity Address as well as ones that contain a private
23126 address, even if the peer device has distributed its IRK in the past
23130 and additionally, if @var{controller-mode} is set to @code{'dual}:
23134 @code{'limited-network}: Apply Limited Discoverable Mode to advertising, which
23135 follows the same policy as to BR/EDR that publishes the identity address when
23136 discoverable, and Network Privacy Mode for scanning
23139 @code{'limited-device}: Apply Limited Discoverable Mode to advertising, which
23140 follows the same policy as to BR/EDR that publishes the identity address when
23141 discoverable, and Device Privacy Mode for scanning.
23145 @item @code{just-works-repairing} (default: @code{'never})
23146 Specify the policy to the JUST-WORKS repairing initiated by peer.
23161 @item @code{temporary-timeout} (default: @code{30})
23162 How long to keep temporary devices around. The value is in seconds. @code{0}
23163 disables the timer completely.
23165 @item @code{refresh-discovery?} (default: @code{#t})
23166 Enables the device to issue an SDP request to update known services when
23167 profile is connected.
23169 @item @code{experimental} (default: @code{#f})
23170 Enables experimental features and interfaces, alternatively a list of UUIDs
23183 @code{(list (uuid <uuid-1>) (uuid <uuid-2>) ...)}.
23186 List of possible UUIDs:
23189 @code{d4992530-b9ec-469f-ab01-6c481c47da1c}: BlueZ Experimental Debug,
23192 @code{671b10b5-42c0-4696-9227-eb28d1b049d6}: BlueZ Experimental Simultaneous Central and Peripheral,
23195 @code{"15c0a148-c273-11ea-b3de-0242ac130004}: BlueZ Experimental LL privacy,
23198 @code{330859bc-7506-492d-9370-9a6f0614037f}: BlueZ Experimental Bluetooth Quality Report,
23201 @code{a6695ace-ee7f-4fb9-881a-5fac66c629af}: BlueZ Experimental Offload Codecs.
23204 @item @code{remote-name-request-retry-delay} (default: @code{300})
23205 The duration to avoid retrying to resolve a peer's name, if the previous
23208 @item @code{page-scan-type} (default: @code{#f})
23209 BR/EDR Page scan activity type.
23211 @item @code{page-scan-interval} (default: @code{#f})
23212 BR/EDR Page scan activity interval.
23214 @item @code{page-scan-window} (default: @code{#f})
23215 BR/EDR Page scan activity window.
23217 @item @code{inquiry-scan-type} (default: @code{#f})
23218 BR/EDR Inquiry scan activity type.
23220 @item @code{inquiry-scan-interval} (default: @code{#f})
23221 BR/EDR Inquiry scan activity interval.
23223 @item @code{inquiry-scan-window} (default: @code{#f})
23224 BR/EDR Inquiry scan activity window.
23226 @item @code{link-supervision-timeout} (default: @code{#f})
23227 BR/EDR Link supervision timeout.
23229 @item @code{page-timeout} (default: @code{#f})
23230 BR/EDR Page timeout.
23232 @item @code{min-sniff-interval} (default: @code{#f})
23233 BR/EDR minimum sniff interval.
23235 @item @code{max-sniff-interval} (default: @code{#f})
23236 BR/EDR maximum sniff interval.
23238 @item @code{min-advertisement-interval} (default: @code{#f})
23239 LE minimum advertisement interval (used for legacy advertisement only).
23241 @item @code{max-advertisement-interval} (default: @code{#f})
23242 LE maximum advertisement interval (used for legacy advertisement only).
23244 @item @code{multi-advertisement-rotation-interval} (default: @code{#f})
23245 LE multiple advertisement rotation interval.
23247 @item @code{scan-interval-auto-connect} (default: @code{#f})
23248 LE scanning interval used for passive scanning supporting auto connect.
23250 @item @code{scan-window-auto-connect} (default: @code{#f})
23251 LE scanning window used for passive scanning supporting auto connect.
23253 @item @code{scan-interval-suspend} (default: @code{#f})
23254 LE scanning interval used for active scanning supporting wake from suspend.
23256 @item @code{scan-window-suspend} (default: @code{#f})
23257 LE scanning window used for active scanning supporting wake from suspend.
23259 @item @code{scan-interval-discovery} (default: @code{#f})
23260 LE scanning interval used for active scanning supporting discovery.
23262 @item @code{scan-window-discovery} (default: @code{#f})
23263 LE scanning window used for active scanning supporting discovery.
23265 @item @code{scan-interval-adv-monitor} (default: @code{#f})
23266 LE scanning interval used for passive scanning supporting the advertisement monitor APIs.
23268 @item @code{scan-window-adv-monitor} (default: @code{#f})
23269 LE scanning window used for passive scanning supporting the advertisement monitor APIs.
23271 @item @code{scan-interval-connect} (default: @code{#f})
23272 LE scanning interval used for connection establishment.
23274 @item @code{scan-window-connect} (default: @code{#f})
23275 LE scanning window used for connection establishment.
23277 @item @code{min-connection-interval} (default: @code{#f})
23278 LE default minimum connection interval. This value is superseded by any specific
23279 value provided via the Load Connection Parameters interface.
23281 @item @code{max-connection-interval} (default: @code{#f})
23282 LE default maximum connection interval. This value is superseded by any specific
23283 value provided via the Load Connection Parameters interface.
23285 @item @code{connection-latency} (default: @code{#f})
23286 LE default connection latency. This value is superseded by any specific
23287 value provided via the Load Connection Parameters interface.
23289 @item @code{connection-supervision-timeout} (default: @code{#f})
23290 LE default connection supervision timeout. This value is superseded by any specific
23291 value provided via the Load Connection Parameters interface.
23293 @item @code{autoconnect-timeout} (default: @code{#f})
23294 LE default autoconnect timeout. This value is superseded by any specific
23295 value provided via the Load Connection Parameters interface.
23297 @item @code{adv-mon-allowlist-scan-duration} (default: @code{300})
23298 Allowlist scan duration during interleaving scan. Only used when scanning for ADV
23299 monitors. The units are msec.
23301 @item @code{adv-mon-no-filter-scan-duration} (default: @code{500})
23302 No filter scan duration during interleaving scan. Only used when scanning for ADV
23303 monitors. The units are msec.
23305 @item @code{enable-adv-mon-interleave-scan?} (default: @code{#t})
23306 Enable/Disable Advertisement Monitor interleave scan for power saving.
23308 @item @code{cache} (default: @code{'always})
23309 GATT attribute cache.
23311 Possible values are:
23314 @code{'always}: Always cache attributes even for devices not paired, this is
23315 recommended as it is best for interoperability, with more consistent
23316 reconnection times and enables proper tracking of notifications for all
23320 @code{'yes}: Only cache attributes of paired devices
23323 @code{'no}: Never cache attributes.
23326 @item @code{key-size} (default: @code{0})
23327 Minimum required Encryption Key Size for accessing secured characteristics.
23329 Possible values are:
23332 @code{0}: Don't care
23335 @code{7 <= N <= 16}
23338 @item @code{exchange-mtu} (default: @code{517})
23339 Exchange MTU size. Possible values are:
23343 @code{23 <= N <= 517}
23346 @item @code{att-channels} (default: @code{3})
23347 Number of ATT channels. Possible values are:
23351 @code{1}: Disables EATT
23357 @item @code{session-mode} (default: @code{'basic})
23358 AVDTP L2CAP signalling channel mode.
23360 Possible values are:
23364 @code{'basic}: Use L2CAP basic mode
23367 @code{'ertm}: Use L2CAP enhanced retransmission mode.
23370 @item @code{stream-mode} (default: @code{'basic})
23371 AVDTP L2CAP transport channel mode.
23373 Possible values are:
23377 @code{'basic}: Use L2CAP basic mode
23380 @code{'streaming}: Use L2CAP streaming mode.
23383 @item @code{reconnect-uuids} (default: @code{'()})
23384 The ReconnectUUIDs defines the set of remote services that should try
23385 to be reconnected to in case of a link loss (link supervision
23386 timeout). The policy plugin should contain a sane set of values by
23387 default, but this list can be overridden here. By setting the list to
23388 empty the reconnection feature gets disabled.
23397 @code{(list (uuid <uuid-1>) (uuid <uuid-2>) ...)}.
23400 @item @code{reconnect-attempts} (default: @code{7})
23401 Defines the number of attempts to reconnect after a link lost. Setting
23402 the value to 0 disables reconnecting feature.
23404 @item @code{reconnect-intervals} (default: @code{'(1 2 4 8 16 32 64)})
23405 Defines a list of intervals in seconds to use in between attempts. If
23406 the number of attempts defined in @var{reconnect-attempts} is bigger than
23407 the list of intervals the last interval is repeated until the last attempt.
23409 @item @code{auto-enable?} (default: @code{#f})
23410 Defines option to enable all controllers when they are found. This includes
23411 adapters present on start as well as adapters that are plugged in later on.
23413 @item @code{resume-delay} (default: @code{2})
23414 Audio devices that were disconnected due to suspend will be reconnected on
23415 resume. @var{resume-delay} determines the delay between when the controller
23416 resumes from suspend and a connection attempt is made. A longer delay is
23417 better for better co-existence with Wi-Fi. The value is in seconds.
23419 @item @code{rssi-sampling-period} (default: @code{#xFF})
23420 Default RSSI Sampling Period. This is used when a client registers an
23421 advertisement monitor and leaves the RSSISamplingPeriod unset.
23423 Possible values are:
23426 @code{#x0}: Report all advertisements
23429 @code{N = #xXX}: Report advertisements every N x 100 msec (range: #x01 to #xFE)
23432 @code{#xFF}: Report only one advertisement per device during monitoring period.
23438 @defvr {Scheme Variable} gnome-keyring-service-type
23439 This is the type of the service that adds the
23440 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
23441 value is a @code{gnome-keyring-configuration} object (see below).
23443 This service adds the @code{gnome-keyring} package to the system profile
23444 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
23445 a user's login keyring when they log in or setting its password with passwd.
23448 @deftp {Data Type} gnome-keyring-configuration
23449 Configuration record for the GNOME Keyring service.
23452 @item @code{keyring} (default: @code{gnome-keyring})
23453 The GNOME keyring package to use.
23455 @item @code{pam-services}
23456 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
23457 services to extend, where @var{service} is the name of an existing
23458 service to extend and @var{kind} is one of @code{login} or
23461 If @code{login} is given, it adds an optional
23462 @code{pam_gnome_keyring.so} to the auth block without arguments and to
23463 the session block with @code{auto_start}. If @code{passwd} is given, it
23464 adds an optional @code{pam_gnome_keyring.so} to the password block
23467 By default, this field contains ``gdm-password'' with the value @code{login}
23468 and ``passwd'' is with the value @code{passwd}.
23472 @defvr {Scheme Variable} seatd-service-type
23473 @uref{https://sr.ht/~kennylevinsen/seatd/, seatd} is a minimal seat
23476 Seat management takes care of mediating access to shared devices (graphics,
23477 input), without requiring the applications needing access to be root.
23482 ;; make sure seatd is running
23483 (service seatd-service-type))
23485 ;; normally one would want %base-services
23490 @code{seatd} operates over a UNIX domain socket, with @code{libseat}
23491 providing the client side of the protocol. Applications that acquire
23492 access to the shared resources via @code{seatd} (e.g. @code{sway})
23493 need to be able to talk to this socket.
23494 This can be achieved by adding the user they run under to the group
23495 owning @code{seatd}'s socket (usually ``seat''), like so:
23501 (supplementary-groups '("wheel" ; allow use of sudo, etc.
23502 "seat" ; seat management
23503 "audio" ; sound card
23504 "video" ; video devices such as webcams
23505 "cdrom")) ; the good ol' CD-ROM
23506 (comment "Bob's sister"))
23509 Depending on your setup, you will have to not only add regular users,
23510 but also system users to this group. For instance, some greetd greeters
23511 require graphics and therefore also need to negotiate with seatd.
23515 @deftp {Data Type} seatd-configuration
23516 Configuration record for the seatd daemon service.
23519 @item @code{seatd} (default: @code{seatd})
23520 The seatd package to use.
23522 @item @code{group} (default: @samp{"seat"})
23523 Group to own the seatd socket.
23525 @item @code{socket} (default: @samp{"/run/seatd.sock"})
23526 Where to create the seatd socket.
23528 @item @code{logfile} (default: @samp{"/var/log/seatd.log"})
23529 Log file to write to.
23531 @item @code{loglevel} (default: @samp{"error"})
23532 Log level to output logs. Possible values: @samp{"silent"}, @samp{"error"},
23533 @samp{"info"} and @samp{"debug"}.
23539 @node Sound Services
23540 @subsection Sound Services
23542 @cindex sound support
23544 @cindex PulseAudio, sound support
23546 The @code{(gnu services sound)} module provides a service to configure the
23547 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
23548 preferred ALSA output driver.
23550 @deffn {Scheme Variable} alsa-service-type
23551 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
23552 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
23553 configuration file. The value for this type is a @command{alsa-configuration}
23554 record as in this example:
23557 (service alsa-service-type)
23560 See below for details about @code{alsa-configuration}.
23563 @deftp {Data Type} alsa-configuration
23564 Data type representing the configuration for @code{alsa-service}.
23567 @item @code{alsa-plugins} (default: @var{alsa-plugins})
23568 @code{alsa-plugins} package to use.
23570 @item @code{pulseaudio?} (default: @var{#t})
23571 Whether ALSA applications should transparently be made to use the
23572 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
23574 Using PulseAudio allows you to run several sound-producing applications
23575 at the same time and to individual control them @i{via}
23576 @command{pavucontrol}, among other things.
23578 @item @code{extra-options} (default: @var{""})
23579 String to append to the @file{/etc/asound.conf} file.
23584 Individual users who want to override the system configuration of ALSA can do
23585 it with the @file{~/.asoundrc} file:
23588 # In guix, we have to specify the absolute path for plugins.
23590 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
23593 # Routing ALSA to jack:
23594 # <http://jackaudio.org/faq/routing_alsa.html>.
23598 0 system:playback_1
23599 1 system:playback_2
23616 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
23619 @deffn {Scheme Variable} pulseaudio-service-type
23620 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
23621 sound server. It exists to allow system overrides of the default settings
23622 via @code{pulseaudio-configuration}, see below.
23625 This service overrides per-user configuration files. If you want
23626 PulseAudio to honor configuration files in @file{~/.config/pulse} you
23627 have to unset the environment variables @env{PULSE_CONFIG} and
23628 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
23632 This service on its own does not ensure, that the @code{pulseaudio} package
23633 exists on your machine. It merely adds configuration files for it, as
23634 detailed below. In the (admittedly unlikely) case, that you find yourself
23635 without a @code{pulseaudio} package, consider enabling it through the
23636 @code{alsa-service-type} above.
23640 @deftp {Data Type} pulseaudio-configuration
23641 Data type representing the configuration for @code{pulseaudio-service}.
23644 @item @code{client-conf} (default: @code{'()})
23645 List of settings to set in @file{client.conf}.
23646 Accepts a list of strings or symbol-value pairs. A string will be
23647 inserted as-is with a newline added. A pair will be formatted as
23648 ``key = value'', again with a newline added.
23650 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
23651 List of settings to set in @file{daemon.conf}, formatted just like
23654 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
23655 Script file to use as @file{default.pa}. In case the
23656 @code{extra-script-files} field below is used, an @code{.include}
23657 directive pointing to @file{/etc/pulse/default.pa.d} is appended to the
23660 @item @code{extra-script-files} (default: @code{'()})
23661 A list of file-like objects defining extra PulseAudio scripts to run at
23662 the initialization of the @command{pulseaudio} daemon, after the main
23663 @code{script-file}. The scripts are deployed to the
23664 @file{/etc/pulse/default.pa.d} directory; they should have the
23665 @samp{.pa} file name extension. For a reference of the available
23666 commands, refer to @command{man pulse-cli-syntax}.
23668 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
23669 Script file to use as @file{system.pa}.
23672 The example below sets the default PulseAudio card profile, the default
23673 sink and the default source to use for a old SoundBlaster Audigy sound
23676 (pulseaudio-configuration
23677 (extra-script-files
23678 (list (plain-file "audigy.pa"
23680 set-card-profile alsa_card.pci-0000_01_01.0 \
23681 output:analog-surround-40+input:analog-mono
23682 set-default-source alsa_input.pci-0000_01_01.0.analog-mono
23683 set-default-sink alsa_output.pci-0000_01_01.0.analog-surround-40\n")))))
23686 Note that @code{pulseaudio-service-type} is part of
23687 @code{%desktop-services}; if your operating system declaration was
23688 derived from one of the desktop templates, you'll want to adjust the
23689 above example to modify the existing @code{pulseaudio-service-type} via
23690 @code{modify-services} (@pxref{Service Reference,
23691 @code{modify-services}}), instead of defining a new one.
23695 @deffn {Scheme Variable} ladspa-service-type
23696 This service sets the @var{LADSPA_PATH} variable, so that programs, which
23697 respect it, e.g. PulseAudio, can load LADSPA plugins.
23699 The following example will setup the service to enable modules from the
23700 @code{swh-plugins} package:
23703 (service ladspa-service-type
23704 (ladspa-configuration (plugins (list swh-plugins))))
23707 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
23712 @node Database Services
23713 @subsection Database Services
23717 The @code{(gnu services databases)} module provides the following services.
23719 @subsubheading PostgreSQL
23721 The following example describes a PostgreSQL service with the default
23725 (service postgresql-service-type
23726 (postgresql-configuration
23727 (postgresql postgresql-10)))
23730 If the services fails to start, it may be due to an incompatible
23731 cluster already present in @var{data-directory}. Adjust it (or, if you
23732 don't need the cluster anymore, delete @var{data-directory}), then
23733 restart the service.
23735 Peer authentication is used by default and the @code{postgres} user
23736 account has no shell, which prevents the direct execution of @code{psql}
23737 commands as this user. To use @code{psql}, you can temporarily log in
23738 as @code{postgres} using a shell, create a PostgreSQL superuser with the
23739 same name as one of the system users and then create the associated
23743 sudo -u postgres -s /bin/sh
23744 createuser --interactive
23745 createdb $MY_USER_LOGIN # Replace appropriately.
23748 @deftp {Data Type} postgresql-configuration
23749 Data type representing the configuration for the
23750 @code{postgresql-service-type}.
23753 @item @code{postgresql}
23754 PostgreSQL package to use for the service.
23756 @item @code{port} (default: @code{5432})
23757 Port on which PostgreSQL should listen.
23759 @item @code{locale} (default: @code{"en_US.utf8"})
23760 Locale to use as the default when creating the database cluster.
23762 @item @code{config-file} (default: @code{(postgresql-config-file)})
23763 The configuration file to use when running PostgreSQL@. The default
23764 behaviour uses the postgresql-config-file record with the default values
23767 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
23768 The directory where @command{pg_ctl} output will be written in a file
23769 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
23770 configuration errors for instance.
23772 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
23773 Directory in which to store the data.
23775 @item @code{extension-packages} (default: @code{'()})
23776 @cindex postgresql extension-packages
23777 Additional extensions are loaded from packages listed in
23778 @var{extension-packages}. Extensions are available at runtime. For instance,
23779 to create a geographic database using the @code{postgis} extension, a user can
23780 configure the postgresql-service as in this example:
23784 (use-package-modules databases geo)
23788 ;; postgresql is required to run `psql' but postgis is not required for
23789 ;; proper operation.
23790 (packages (cons* postgresql %base-packages))
23793 (service postgresql-service-type
23794 (postgresql-configuration
23795 (postgresql postgresql-10)
23796 (extension-packages (list postgis))))
23800 Then the extension becomes visible and you can initialise an empty geographic
23801 database in this way:
23805 > create database postgistest;
23806 > \connect postgistest;
23807 > create extension postgis;
23808 > create extension postgis_topology;
23811 There is no need to add this field for contrib extensions such as hstore or
23812 dblink as they are already loadable by postgresql. This field is only
23813 required to add extensions provided by other packages.
23818 @deftp {Data Type} postgresql-config-file
23819 Data type representing the PostgreSQL configuration file. As shown in
23820 the following example, this can be used to customize the configuration
23821 of PostgreSQL@. Note that you can use any G-expression or filename in
23822 place of this record, if you already have a configuration file you'd
23823 like to use for example.
23826 (service postgresql-service-type
23827 (postgresql-configuration
23829 (postgresql-config-file
23830 (log-destination "stderr")
23832 (plain-file "pg_hba.conf"
23834 local all all trust
23835 host all all 127.0.0.1/32 md5
23836 host all all ::1/128 md5"))
23838 '(("session_preload_libraries" "auto_explain")
23839 ("random_page_cost" 2)
23840 ("auto_explain.log_min_duration" "100 ms")
23841 ("work_mem" "500 MB")
23842 ("logging_collector" #t)
23843 ("log_directory" "/var/log/postgresql")))))))
23847 @item @code{log-destination} (default: @code{"syslog"})
23848 The logging method to use for PostgreSQL@. Multiple values are accepted,
23849 separated by commas.
23851 @item @code{hba-file} (default: @code{%default-postgres-hba})
23852 Filename or G-expression for the host-based authentication
23855 @item @code{ident-file} (default: @code{%default-postgres-ident})
23856 Filename or G-expression for the user name mapping configuration.
23858 @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
23859 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
23860 is to listen for connections from client applications. If set to
23861 @code{""} PostgreSQL does not listen on any Unix-domain sockets, in
23862 which case only TCP/IP sockets can be used to connect to the server.
23864 By default, the @code{#false} value means the PostgreSQL default value
23865 will be used, which is currently @samp{/tmp}.
23867 @item @code{extra-config} (default: @code{'()})
23868 List of additional keys and values to include in the PostgreSQL config
23869 file. Each entry in the list should be a list where the first element
23870 is the key, and the remaining elements are the values.
23872 The values can be numbers, booleans or strings and will be mapped to
23873 PostgreSQL parameters types @code{Boolean}, @code{String},
23874 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
23875 @uref{https://www.postgresql.org/docs/current/config-setting.html,
23881 @deffn {Scheme Variable} postgresql-role-service-type
23882 This service allows to create PostgreSQL roles and databases after
23883 PostgreSQL service start. Here is an example of its use.
23886 (service postgresql-role-service-type
23887 (postgresql-role-configuration
23889 (list (postgresql-role
23891 (create-database? #t))))))
23894 This service can be extended with extra roles, as in this
23898 (service-extension postgresql-role-service-type
23899 (const (postgresql-role
23901 (create-database? #t))))
23905 @deftp {Data Type} postgresql-role
23906 PostgreSQL manages database access permissions using the concept of
23907 roles. A role can be thought of as either a database user, or a group
23908 of database users, depending on how the role is set up. Roles can own
23909 database objects (for example, tables) and can assign privileges on
23910 those objects to other roles to control who has access to which objects.
23916 @item @code{permissions} (default: @code{'(createdb login)})
23917 The role permissions list. Supported permissions are @code{bypassrls},
23918 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
23921 @item @code{create-database?} (default: @code{#f})
23922 Whether to create a database with the same name as the role.
23927 @deftp {Data Type} postgresql-role-configuration
23928 Data type representing the configuration of
23929 @var{postgresql-role-service-type}.
23932 @item @code{host} (default: @code{"/var/run/postgresql"})
23933 The PostgreSQL host to connect to.
23935 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
23936 File name of the log file.
23938 @item @code{roles} (default: @code{'()})
23939 The initial PostgreSQL roles to create.
23943 @subsubheading MariaDB/MySQL
23945 @defvr {Scheme Variable} mysql-service-type
23946 This is the service type for a MySQL or MariaDB database server. Its value
23947 is a @code{mysql-configuration} object that specifies which package to use,
23948 as well as various settings for the @command{mysqld} daemon.
23951 @deftp {Data Type} mysql-configuration
23952 Data type representing the configuration of @var{mysql-service-type}.
23955 @item @code{mysql} (default: @var{mariadb})
23956 Package object of the MySQL database server, can be either @var{mariadb}
23959 For MySQL, a temporary root password will be displayed at activation time.
23960 For MariaDB, the root password is empty.
23962 @item @code{bind-address} (default: @code{"127.0.0.1"})
23963 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
23964 to bind to all available network interfaces.
23966 @item @code{port} (default: @code{3306})
23967 TCP port on which the database server listens for incoming connections.
23969 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
23970 Socket file to use for local (non-network) connections.
23972 @item @code{extra-content} (default: @code{""})
23973 Additional settings for the @file{my.cnf} configuration file.
23975 @item @code{extra-environment} (default: @code{#~'()})
23976 List of environment variables passed to the @command{mysqld} process.
23978 @item @code{auto-upgrade?} (default: @code{#t})
23979 Whether to automatically run @command{mysql_upgrade} after starting the
23980 service. This is necessary to upgrade the @dfn{system schema} after
23981 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
23982 be disabled if you would rather do that manually.
23987 @subsubheading Memcached
23989 @defvr {Scheme Variable} memcached-service-type
23990 This is the service type for the @uref{https://memcached.org/,
23991 Memcached} service, which provides a distributed in memory cache. The
23992 value for the service type is a @code{memcached-configuration} object.
23996 (service memcached-service-type)
23999 @deftp {Data Type} memcached-configuration
24000 Data type representing the configuration of memcached.
24003 @item @code{memcached} (default: @code{memcached})
24004 The Memcached package to use.
24006 @item @code{interfaces} (default: @code{'("0.0.0.0")})
24007 Network interfaces on which to listen.
24009 @item @code{tcp-port} (default: @code{11211})
24010 Port on which to accept connections.
24012 @item @code{udp-port} (default: @code{11211})
24013 Port on which to accept UDP connections on, a value of 0 will disable
24014 listening on a UDP socket.
24016 @item @code{additional-options} (default: @code{'()})
24017 Additional command line options to pass to @code{memcached}.
24021 @subsubheading Redis
24023 @defvr {Scheme Variable} redis-service-type
24024 This is the service type for the @uref{https://redis.io/, Redis}
24025 key/value store, whose value is a @code{redis-configuration} object.
24028 @deftp {Data Type} redis-configuration
24029 Data type representing the configuration of redis.
24032 @item @code{redis} (default: @code{redis})
24033 The Redis package to use.
24035 @item @code{bind} (default: @code{"127.0.0.1"})
24036 Network interface on which to listen.
24038 @item @code{port} (default: @code{6379})
24039 Port on which to accept connections on, a value of 0 will disable
24040 listening on a TCP socket.
24042 @item @code{working-directory} (default: @code{"/var/lib/redis"})
24043 Directory in which to store the database and related files.
24047 @node Mail Services
24048 @subsection Mail Services
24052 The @code{(gnu services mail)} module provides Guix service definitions
24053 for email services: IMAP, POP3, and LMTP servers, as well as mail
24054 transport agents (MTAs). Lots of acronyms! These services are detailed
24055 in the subsections below.
24057 @subsubheading Dovecot Service
24059 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
24060 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
24063 By default, Dovecot does not need much configuration; the default
24064 configuration object created by @code{(dovecot-configuration)} will
24065 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
24066 certificate will be generated for TLS-protected connections, though
24067 Dovecot will also listen on cleartext ports by default. There are a
24068 number of options, though, which mail administrators might need to change,
24069 and as is the case with other services, Guix allows the system
24070 administrator to specify these parameters via a uniform Scheme interface.
24072 For example, to specify that mail is located at @code{maildir~/.mail},
24073 one would instantiate the Dovecot service like this:
24076 (dovecot-service #:config
24077 (dovecot-configuration
24078 (mail-location "maildir:~/.mail")))
24081 The available configuration parameters follow. Each parameter
24082 definition is preceded by its type; for example, @samp{string-list foo}
24083 indicates that the @code{foo} parameter should be specified as a list of
24084 strings. There is also a way to specify the configuration as a string,
24085 if you have an old @code{dovecot.conf} file that you want to port over
24086 from some other system; see the end for more details.
24088 @c The following documentation was initially generated by
24089 @c (generate-documentation) in (gnu services mail). Manually maintained
24090 @c documentation is better, so we shouldn't hesitate to edit below as
24091 @c needed. However if the change you want to make to this documentation
24092 @c can be done in an automated way, it's probably easier to change
24093 @c (generate-documentation) than to make it below and have to deal with
24094 @c the churn as dovecot updates.
24096 Available @code{dovecot-configuration} fields are:
24098 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
24099 The dovecot package.
24102 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
24103 A list of IPs or hosts where to listen for connections. @samp{*}
24104 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
24105 interfaces. If you want to specify non-default ports or anything more
24106 complex, customize the address and port fields of the
24107 @samp{inet-listener} of the specific services you are interested in.
24110 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
24111 List of protocols we want to serve. Available protocols include
24112 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
24114 Available @code{protocol-configuration} fields are:
24116 @deftypevr {@code{protocol-configuration} parameter} string name
24117 The name of the protocol.
24120 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
24121 UNIX socket path to the master authentication server to find users.
24122 This is used by imap (for shared users) and lda.
24123 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
24126 @deftypevr {@code{protocol-configuration} parameter} boolean imap-metadata?
24127 Whether to enable the @code{IMAP METADATA} extension as defined in
24128 @uref{https://tools.ietf.org/html/rfc5464,RFC@tie{}5464}, which provides
24129 a means for clients to set and retrieve per-mailbox, per-user metadata
24130 and annotations over IMAP.
24132 If this is @samp{#t}, you must also specify a dictionary @i{via} the
24133 @code{mail-attribute-dict} setting.
24135 Defaults to @samp{#f}.
24139 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list managesieve-notify-capabilities
24140 Which NOTIFY capabilities to report to clients that first connect to
24141 the ManageSieve service, before authentication. These may differ from the
24142 capabilities offered to authenticated users. If this field is left empty,
24143 report what the Sieve interpreter supports by default.
24145 Defaults to @samp{()}.
24148 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list managesieve-sieve-capability
24149 Which SIEVE capabilities to report to clients that first connect to
24150 the ManageSieve service, before authentication. These may differ from the
24151 capabilities offered to authenticated users. If this field is left empty,
24152 report what the Sieve interpreter supports by default.
24154 Defaults to @samp{()}.
24158 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
24159 Space separated list of plugins to load.
24162 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
24163 Maximum number of IMAP connections allowed for a user from each IP
24164 address. NOTE: The username is compared case-sensitively.
24165 Defaults to @samp{10}.
24170 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
24171 List of services to enable. Available services include @samp{imap},
24172 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
24175 Available @code{service-configuration} fields are:
24177 @deftypevr {@code{service-configuration} parameter} string kind
24178 The service kind. Valid values include @code{director},
24179 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
24180 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
24181 @code{tcpwrap}, @code{quota-warning}, or anything else.
24184 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
24185 Listeners for the service. A listener is either a
24186 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
24187 an @code{inet-listener-configuration}.
24188 Defaults to @samp{()}.
24190 Available @code{unix-listener-configuration} fields are:
24192 @deftypevr {@code{unix-listener-configuration} parameter} string path
24193 Path to the file, relative to @code{base-dir} field. This is also used as
24197 @deftypevr {@code{unix-listener-configuration} parameter} string mode
24198 The access mode for the socket.
24199 Defaults to @samp{"0600"}.
24202 @deftypevr {@code{unix-listener-configuration} parameter} string user
24203 The user to own the socket.
24204 Defaults to @samp{""}.
24207 @deftypevr {@code{unix-listener-configuration} parameter} string group
24208 The group to own the socket.
24209 Defaults to @samp{""}.
24213 Available @code{fifo-listener-configuration} fields are:
24215 @deftypevr {@code{fifo-listener-configuration} parameter} string path
24216 Path to the file, relative to @code{base-dir} field. This is also used as
24220 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
24221 The access mode for the socket.
24222 Defaults to @samp{"0600"}.
24225 @deftypevr {@code{fifo-listener-configuration} parameter} string user
24226 The user to own the socket.
24227 Defaults to @samp{""}.
24230 @deftypevr {@code{fifo-listener-configuration} parameter} string group
24231 The group to own the socket.
24232 Defaults to @samp{""}.
24236 Available @code{inet-listener-configuration} fields are:
24238 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
24239 The protocol to listen for.
24242 @deftypevr {@code{inet-listener-configuration} parameter} string address
24243 The address on which to listen, or empty for all addresses.
24244 Defaults to @samp{""}.
24247 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
24248 The port on which to listen.
24251 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
24252 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
24254 Defaults to @samp{#t}.
24259 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
24260 Maximum number of simultaneous client connections per process. Once
24261 this number of connections is received, the next incoming connection
24262 will prompt Dovecot to spawn another process. If set to 0,
24263 @code{default-client-limit} is used instead.
24265 Defaults to @samp{0}.
24269 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
24270 Number of connections to handle before starting a new process.
24271 Typically the only useful values are 0 (unlimited) or 1. 1 is more
24272 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
24273 Defaults to @samp{1}.
24277 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
24278 Maximum number of processes that can exist for this service. If set to
24279 0, @code{default-process-limit} is used instead.
24281 Defaults to @samp{0}.
24285 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
24286 Number of processes to always keep waiting for more connections.
24287 Defaults to @samp{0}.
24290 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
24291 If you set @samp{service-count 0}, you probably need to grow
24293 Defaults to @samp{256000000}.
24298 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
24299 Dict configuration, as created by the @code{dict-configuration}
24302 Available @code{dict-configuration} fields are:
24304 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
24305 A list of key-value pairs that this dict should hold.
24306 Defaults to @samp{()}.
24311 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
24312 A list of passdb configurations, each one created by the
24313 @code{passdb-configuration} constructor.
24315 Available @code{passdb-configuration} fields are:
24317 @deftypevr {@code{passdb-configuration} parameter} string driver
24318 The driver that the passdb should use. Valid values include
24319 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
24321 Defaults to @samp{"pam"}.
24324 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
24325 Space separated list of arguments to the passdb driver.
24326 Defaults to @samp{""}.
24331 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
24332 List of userdb configurations, each one created by the
24333 @code{userdb-configuration} constructor.
24335 Available @code{userdb-configuration} fields are:
24337 @deftypevr {@code{userdb-configuration} parameter} string driver
24338 The driver that the userdb should use. Valid values include
24339 @samp{passwd} and @samp{static}.
24340 Defaults to @samp{"passwd"}.
24343 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
24344 Space separated list of arguments to the userdb driver.
24345 Defaults to @samp{""}.
24348 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
24349 Override fields from passwd.
24350 Defaults to @samp{()}.
24355 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
24356 Plug-in configuration, created by the @code{plugin-configuration}
24360 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
24361 List of namespaces. Each item in the list is created by the
24362 @code{namespace-configuration} constructor.
24364 Available @code{namespace-configuration} fields are:
24366 @deftypevr {@code{namespace-configuration} parameter} string name
24367 Name for this namespace.
24370 @deftypevr {@code{namespace-configuration} parameter} string type
24371 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
24372 Defaults to @samp{"private"}.
24375 @deftypevr {@code{namespace-configuration} parameter} string separator
24376 Hierarchy separator to use. You should use the same separator for
24377 all namespaces or some clients get confused. @samp{/} is usually a good
24378 one. The default however depends on the underlying mail storage
24380 Defaults to @samp{""}.
24383 @deftypevr {@code{namespace-configuration} parameter} string prefix
24384 Prefix required to access this namespace. This needs to be
24385 different for all namespaces. For example @samp{Public/}.
24386 Defaults to @samp{""}.
24389 @deftypevr {@code{namespace-configuration} parameter} string location
24390 Physical location of the mailbox. This is in the same format as
24391 mail_location, which is also the default for it.
24392 Defaults to @samp{""}.
24395 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
24396 There can be only one INBOX, and this setting defines which
24398 Defaults to @samp{#f}.
24401 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
24402 If namespace is hidden, it's not advertised to clients via NAMESPACE
24403 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
24404 useful when converting from another server with different namespaces
24405 which you want to deprecate but still keep working. For example you can
24406 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
24408 Defaults to @samp{#f}.
24411 @deftypevr {@code{namespace-configuration} parameter} boolean list?
24412 Show the mailboxes under this namespace with the LIST command. This
24413 makes the namespace visible for clients that do not support the NAMESPACE
24414 extension. The special @code{children} value lists child mailboxes, but
24415 hides the namespace prefix.
24416 Defaults to @samp{#t}.
24419 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
24420 Namespace handles its own subscriptions. If set to @code{#f}, the
24421 parent namespace handles them. The empty prefix should always have this
24423 Defaults to @samp{#t}.
24426 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
24427 List of predefined mailboxes in this namespace.
24428 Defaults to @samp{()}.
24430 Available @code{mailbox-configuration} fields are:
24432 @deftypevr {@code{mailbox-configuration} parameter} string name
24433 Name for this mailbox.
24436 @deftypevr {@code{mailbox-configuration} parameter} string auto
24437 @samp{create} will automatically create this mailbox.
24438 @samp{subscribe} will both create and subscribe to the mailbox.
24439 Defaults to @samp{"no"}.
24442 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
24443 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
24444 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
24445 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
24446 Defaults to @samp{()}.
24453 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
24454 Base directory where to store runtime data.
24455 Defaults to @samp{"/var/run/dovecot/"}.
24458 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
24459 Greeting message for clients.
24460 Defaults to @samp{"Dovecot ready."}.
24463 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
24464 List of trusted network ranges. Connections from these IPs are
24465 allowed to override their IP addresses and ports (for logging and for
24466 authentication checks). @samp{disable-plaintext-auth} is also ignored
24467 for these networks. Typically you would specify your IMAP proxy servers
24469 Defaults to @samp{()}.
24472 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
24473 List of login access check sockets (e.g.@: tcpwrap).
24474 Defaults to @samp{()}.
24477 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
24478 Show more verbose process titles (in ps). Currently shows user name
24479 and IP address. Useful for seeing who is actually using the IMAP
24480 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
24482 Defaults to @samp{#f}.
24485 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
24486 Should all processes be killed when Dovecot master process shuts down.
24487 Setting this to @code{#f} means that Dovecot can be upgraded without
24488 forcing existing client connections to close (although that could also
24489 be a problem if the upgrade is e.g.@: due to a security fix).
24490 Defaults to @samp{#t}.
24493 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
24494 If non-zero, run mail commands via this many connections to doveadm
24495 server, instead of running them directly in the same process.
24496 Defaults to @samp{0}.
24499 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
24500 UNIX socket or host:port used for connecting to doveadm server.
24501 Defaults to @samp{"doveadm-server"}.
24504 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
24505 List of environment variables that are preserved on Dovecot startup
24506 and passed down to all of its child processes. You can also give
24507 key=value pairs to always set specific settings.
24510 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
24511 Disable LOGIN command and all other plaintext authentications unless
24512 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
24513 matches the local IP (i.e.@: you're connecting from the same computer),
24514 the connection is considered secure and plaintext authentication is
24515 allowed. See also ssl=required setting.
24516 Defaults to @samp{#t}.
24519 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
24520 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
24521 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
24522 for caching to be used.
24523 Defaults to @samp{0}.
24526 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
24527 Time to live for cached data. After TTL expires the cached record
24528 is no longer used, *except* if the main database lookup returns internal
24529 failure. We also try to handle password changes automatically: If
24530 user's previous authentication was successful, but this one wasn't, the
24531 cache isn't used. For now this works only with plaintext
24533 Defaults to @samp{"1 hour"}.
24536 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
24537 TTL for negative hits (user not found, password mismatch).
24538 0 disables caching them completely.
24539 Defaults to @samp{"1 hour"}.
24542 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
24543 List of realms for SASL authentication mechanisms that need them.
24544 You can leave it empty if you don't want to support multiple realms.
24545 Many clients simply use the first one listed here, so keep the default
24547 Defaults to @samp{()}.
24550 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
24551 Default realm/domain to use if none was specified. This is used for
24552 both SASL realms and appending @@domain to username in plaintext
24554 Defaults to @samp{""}.
24557 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
24558 List of allowed characters in username. If the user-given username
24559 contains a character not listed in here, the login automatically fails.
24560 This is just an extra check to make sure user can't exploit any
24561 potential quote escaping vulnerabilities with SQL/LDAP databases. If
24562 you want to allow all characters, set this value to empty.
24563 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
24566 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
24567 Username character translations before it's looked up from
24568 databases. The value contains series of from -> to characters. For
24569 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
24570 translated to @samp{@@}.
24571 Defaults to @samp{""}.
24574 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
24575 Username formatting before it's looked up from databases. You can
24576 use the standard variables here, e.g.@: %Lu would lowercase the username,
24577 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
24578 change the @samp{@@} into @samp{-AT-}. This translation is done after
24579 @samp{auth-username-translation} changes.
24580 Defaults to @samp{"%Lu"}.
24583 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
24584 If you want to allow master users to log in by specifying the master
24585 username within the normal username string (i.e.@: not using SASL
24586 mechanism's support for it), you can specify the separator character
24587 here. The format is then <username><separator><master username>.
24588 UW-IMAP uses @samp{*} as the separator, so that could be a good
24590 Defaults to @samp{""}.
24593 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
24594 Username to use for users logging in with ANONYMOUS SASL
24596 Defaults to @samp{"anonymous"}.
24599 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
24600 Maximum number of dovecot-auth worker processes. They're used to
24601 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
24602 They're automatically created and destroyed as needed.
24603 Defaults to @samp{30}.
24606 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
24607 Host name to use in GSSAPI principal names. The default is to use
24608 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
24609 allow all keytab entries.
24610 Defaults to @samp{""}.
24613 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
24614 Kerberos keytab to use for the GSSAPI mechanism. Will use the
24615 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
24616 need to change the auth service to run as root to be able to read this
24618 Defaults to @samp{""}.
24621 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
24622 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
24623 and @samp{ntlm-auth} helper.
24624 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
24625 Defaults to @samp{#f}.
24628 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
24629 Path for Samba's @samp{ntlm-auth} helper binary.
24630 Defaults to @samp{"/usr/bin/ntlm_auth"}.
24633 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
24634 Time to delay before replying to failed authentications.
24635 Defaults to @samp{"2 secs"}.
24638 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
24639 Require a valid SSL client certificate or the authentication
24641 Defaults to @samp{#f}.
24644 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
24645 Take the username from client's SSL certificate, using
24646 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
24648 Defaults to @samp{#f}.
24651 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
24652 List of wanted authentication mechanisms. Supported mechanisms are:
24653 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
24654 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
24655 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
24656 @samp{disable-plaintext-auth} setting.
24659 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
24660 List of IPs or hostnames to all director servers, including ourself.
24661 Ports can be specified as ip:port. The default port is the same as what
24662 director service's @samp{inet-listener} is using.
24663 Defaults to @samp{()}.
24666 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
24667 List of IPs or hostnames to all backend mail servers. Ranges are
24668 allowed too, like 10.0.0.10-10.0.0.30.
24669 Defaults to @samp{()}.
24672 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
24673 How long to redirect users to a specific server after it no longer
24674 has any connections.
24675 Defaults to @samp{"15 min"}.
24678 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
24679 How the username is translated before being hashed. Useful values
24680 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
24681 are shared within domain.
24682 Defaults to @samp{"%Lu"}.
24685 @deftypevr {@code{dovecot-configuration} parameter} string log-path
24686 Log file to use for error messages. @samp{syslog} logs to syslog,
24687 @samp{/dev/stderr} logs to stderr.
24688 Defaults to @samp{"syslog"}.
24691 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
24692 Log file to use for informational messages. Defaults to
24694 Defaults to @samp{""}.
24697 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
24698 Log file to use for debug messages. Defaults to
24699 @samp{info-log-path}.
24700 Defaults to @samp{""}.
24703 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
24704 Syslog facility to use if you're logging to syslog. Usually if you
24705 don't want to use @samp{mail}, you'll use local0..local7. Also other
24706 standard facilities are supported.
24707 Defaults to @samp{"mail"}.
24710 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
24711 Log unsuccessful authentication attempts and the reasons why they
24713 Defaults to @samp{#f}.
24716 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
24717 In case of password mismatches, log the attempted password. Valid
24718 values are no, plain and sha1. sha1 can be useful for detecting brute
24719 force password attempts vs. user simply trying the same password over
24720 and over again. You can also truncate the value to n chars by appending
24721 ":n" (e.g.@: sha1:6).
24722 Defaults to @samp{"no"}.
24725 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
24726 Even more verbose logging for debugging purposes. Shows for example
24728 Defaults to @samp{#f}.
24731 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
24732 In case of password mismatches, log the passwords and used scheme so
24733 the problem can be debugged. Enabling this also enables
24735 Defaults to @samp{#f}.
24738 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
24739 Enable mail process debugging. This can help you figure out why
24740 Dovecot isn't finding your mails.
24741 Defaults to @samp{#f}.
24744 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
24745 Show protocol level SSL errors.
24746 Defaults to @samp{#f}.
24749 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
24750 Prefix for each line written to log file. % codes are in
24751 strftime(3) format.
24752 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
24755 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
24756 List of elements we want to log. The elements which have a
24757 non-empty variable value are joined together to form a comma-separated
24761 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
24762 Login log format. %s contains @samp{login-log-format-elements}
24763 string, %$ contains the data we want to log.
24764 Defaults to @samp{"%$: %s"}.
24767 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
24768 Log prefix for mail processes. See doc/wiki/Variables.txt for list
24769 of possible variables you can use.
24770 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
24773 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
24774 Format to use for logging mail deliveries. You can use variables:
24777 Delivery status message (e.g.@: @samp{saved to INBOX})
24789 Defaults to @samp{"msgid=%m: %$"}.
24792 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
24793 Location for users' mailboxes. The default is empty, which means
24794 that Dovecot tries to find the mailboxes automatically. This won't work
24795 if the user doesn't yet have any mail, so you should explicitly tell
24796 Dovecot the full location.
24798 If you're using mbox, giving a path to the INBOX
24799 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
24800 where the other mailboxes are kept. This is called the @emph{root mail
24801 directory}, and it must be the first path given in the
24802 @samp{mail-location} setting.
24804 There are a few special variables you can use, e.g.:
24810 user part in user@@domain, same as %u if there's no domain
24812 domain part in user@@domain, empty if there's no domain
24817 See doc/wiki/Variables.txt for full list. Some examples:
24819 @item maildir:~/Maildir
24820 @item mbox:~/mail:INBOX=/var/mail/%u
24821 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
24823 Defaults to @samp{""}.
24826 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
24827 System user and group used to access mails. If you use multiple,
24828 userdb can override these by returning uid or gid fields. You can use
24829 either numbers or names. <doc/wiki/UserIds.txt>.
24830 Defaults to @samp{""}.
24833 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
24835 Defaults to @samp{""}.
24838 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
24839 Group to enable temporarily for privileged operations. Currently
24840 this is used only with INBOX when either its initial creation or
24841 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
24843 Defaults to @samp{""}.
24846 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
24847 Grant access to these supplementary groups for mail processes.
24848 Typically these are used to set up access to shared mailboxes. Note
24849 that it may be dangerous to set these if users can create symlinks
24850 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
24851 could allow a user to delete others' mailboxes, or @code{ln -s
24852 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
24856 @deftypevr {@code{dovecot-configuration} parameter} string mail-attribute-dict
24857 The location of a dictionary used to store @code{IMAP METADATA}
24858 as defined by @uref{https://tools.ietf.org/html/rfc5464, RFC@tie{}5464}.
24860 The IMAP METADATA commands are available only if the ``imap''
24861 protocol configuration's @code{imap-metadata?} field is @samp{#t}.
24863 Defaults to @samp{""}.
24867 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
24868 Allow full file system access to clients. There's no access checks
24869 other than what the operating system does for the active UID/GID@. It
24870 works with both maildir and mboxes, allowing you to prefix mailboxes
24871 names with e.g.@: @file{/path/} or @file{~user/}.
24872 Defaults to @samp{#f}.
24875 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
24876 Don't use @code{mmap()} at all. This is required if you store indexes to
24877 shared file systems (NFS or clustered file system).
24878 Defaults to @samp{#f}.
24881 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
24882 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
24883 supports @samp{O_EXCL} since version 3, so this should be safe to use
24884 nowadays by default.
24885 Defaults to @samp{#t}.
24888 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
24889 When to use fsync() or fdatasync() calls:
24892 Whenever necessary to avoid losing important data
24894 Useful with e.g.@: NFS when @code{write()}s are delayed
24896 Never use it (best performance, but crashes can lose data).
24898 Defaults to @samp{"optimized"}.
24901 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
24902 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
24903 NFS caches whenever needed. If you're using only a single mail server
24905 Defaults to @samp{#f}.
24908 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
24909 Mail index files also exist in NFS@. Setting this to yes requires
24910 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
24911 Defaults to @samp{#f}.
24914 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
24915 Locking method for index files. Alternatives are fcntl, flock and
24916 dotlock. Dotlocking uses some tricks which may create more disk I/O
24917 than other locking methods. NFS users: flock doesn't work, remember to
24918 change @samp{mmap-disable}.
24919 Defaults to @samp{"fcntl"}.
24922 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
24923 Directory in which LDA/LMTP temporarily stores incoming mails >128
24925 Defaults to @samp{"/tmp"}.
24928 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
24929 Valid UID range for users. This is mostly to make sure that users can't
24930 log in as daemons or other system users. Note that denying root logins is
24931 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
24933 Defaults to @samp{500}.
24936 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
24938 Defaults to @samp{0}.
24941 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
24942 Valid GID range for users. Users having non-valid GID as primary group ID
24943 aren't allowed to log in. If user belongs to supplementary groups with
24944 non-valid GIDs, those groups are not set.
24945 Defaults to @samp{1}.
24948 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
24950 Defaults to @samp{0}.
24953 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
24954 Maximum allowed length for mail keyword name. It's only forced when
24955 trying to create new keywords.
24956 Defaults to @samp{50}.
24959 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
24960 List of directories under which chrooting is allowed for mail
24961 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
24962 too). This setting doesn't affect @samp{login-chroot}
24963 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
24964 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
24965 which local users can modify, that may lead to root exploit. Usually
24966 this should be done only if you don't allow shell access for users.
24967 <doc/wiki/Chrooting.txt>.
24968 Defaults to @samp{()}.
24971 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
24972 Default chroot directory for mail processes. This can be overridden
24973 for specific users in user database by giving @samp{/./} in user's home
24974 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
24975 there is no real need to do chrooting, Dovecot doesn't allow users to
24976 access files outside their mail directory anyway. If your home
24977 directories are prefixed with the chroot directory, append @samp{/.} to
24978 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
24979 Defaults to @samp{""}.
24982 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
24983 UNIX socket path to master authentication server to find users.
24984 This is used by imap (for shared users) and lda.
24985 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
24988 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
24989 Directory where to look up mail plugins.
24990 Defaults to @samp{"/usr/lib/dovecot"}.
24993 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
24994 List of plugins to load for all services. Plugins specific to IMAP,
24995 LDA, etc.@: are added to this list in their own .conf files.
24996 Defaults to @samp{()}.
24999 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
25000 The minimum number of mails in a mailbox before updates are done to
25001 cache file. This allows optimizing Dovecot's behavior to do less disk
25002 writes at the cost of more disk reads.
25003 Defaults to @samp{0}.
25006 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
25007 When IDLE command is running, mailbox is checked once in a while to
25008 see if there are any new mails or other changes. This setting defines
25009 the minimum time to wait between those checks. Dovecot can also use
25010 dnotify, inotify and kqueue to find out immediately when changes
25012 Defaults to @samp{"30 secs"}.
25015 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
25016 Save mails with CR+LF instead of plain LF@. This makes sending those
25017 mails take less CPU, especially with sendfile() syscall with Linux and
25018 FreeBSD@. But it also creates a bit more disk I/O which may just make it
25019 slower. Also note that if other software reads the mboxes/maildirs,
25020 they may handle the extra CRs wrong and cause problems.
25021 Defaults to @samp{#f}.
25024 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
25025 By default LIST command returns all entries in maildir beginning
25026 with a dot. Enabling this option makes Dovecot return only entries
25027 which are directories. This is done by stat()ing each entry, so it
25028 causes more disk I/O.
25029 (For systems setting struct @samp{dirent->d_type} this check is free
25030 and it's done always regardless of this setting).
25031 Defaults to @samp{#f}.
25034 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
25035 When copying a message, do it with hard links whenever possible.
25036 This makes the performance much better, and it's unlikely to have any
25038 Defaults to @samp{#t}.
25041 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
25042 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
25043 directory only when its mtime changes unexpectedly or when we can't find
25044 the mail otherwise.
25045 Defaults to @samp{#f}.
25048 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
25049 Which locking methods to use for locking mbox. There are four
25054 Create <mailbox>.lock file. This is the oldest and most NFS-safe
25055 solution. If you want to use /var/mail/ like directory, the users will
25056 need write access to that directory.
25058 Same as dotlock, but if it fails because of permissions or because there
25059 isn't enough disk space, just skip it.
25061 Use this if possible. Works with NFS too if lockd is used.
25063 May not exist in all systems. Doesn't work with NFS.
25065 May not exist in all systems. Doesn't work with NFS.
25068 You can use multiple locking methods; if you do the order they're declared
25069 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
25070 locking methods as well. Some operating systems don't allow using some of
25071 them simultaneously.
25074 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
25078 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
25079 Maximum time to wait for lock (all of them) before aborting.
25080 Defaults to @samp{"5 mins"}.
25083 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
25084 If dotlock exists but the mailbox isn't modified in any way,
25085 override the lock file after this much time.
25086 Defaults to @samp{"2 mins"}.
25089 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
25090 When mbox changes unexpectedly we have to fully read it to find out
25091 what changed. If the mbox is large this can take a long time. Since
25092 the change is usually just a newly appended mail, it'd be faster to
25093 simply read the new mails. If this setting is enabled, Dovecot does
25094 this but still safely fallbacks to re-reading the whole mbox file
25095 whenever something in mbox isn't how it's expected to be. The only real
25096 downside to this setting is that if some other MUA changes message
25097 flags, Dovecot doesn't notice it immediately. Note that a full sync is
25098 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
25099 Defaults to @samp{#t}.
25102 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
25103 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
25104 EXAMINE, EXPUNGE or CHECK commands. If this is set,
25105 @samp{mbox-dirty-syncs} is ignored.
25106 Defaults to @samp{#f}.
25109 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
25110 Delay writing mbox headers until doing a full write sync (EXPUNGE
25111 and CHECK commands and when closing the mailbox). This is especially
25112 useful for POP3 where clients often delete all mails. The downside is
25113 that our changes aren't immediately visible to other MUAs.
25114 Defaults to @samp{#t}.
25117 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
25118 If mbox size is smaller than this (e.g.@: 100k), don't write index
25119 files. If an index file already exists it's still read, just not
25121 Defaults to @samp{0}.
25124 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
25125 Maximum dbox file size until it's rotated.
25126 Defaults to @samp{10000000}.
25129 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
25130 Maximum dbox file age until it's rotated. Typically in days. Day
25131 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
25133 Defaults to @samp{"1d"}.
25136 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
25137 When creating new mdbox files, immediately preallocate their size to
25138 @samp{mdbox-rotate-size}. This setting currently works only in Linux
25139 with some file systems (ext4, xfs).
25140 Defaults to @samp{#f}.
25143 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
25144 sdbox and mdbox support saving mail attachments to external files,
25145 which also allows single instance storage for them. Other backends
25146 don't support this for now.
25148 WARNING: This feature hasn't been tested much yet. Use at your own risk.
25150 Directory root where to store mail attachments. Disabled, if empty.
25151 Defaults to @samp{""}.
25154 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
25155 Attachments smaller than this aren't saved externally. It's also
25156 possible to write a plugin to disable saving specific attachments
25158 Defaults to @samp{128000}.
25161 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
25162 File system backend to use for saving attachments:
25165 No SiS done by Dovecot (but this might help FS's own deduplication)
25167 SiS with immediate byte-by-byte comparison during saving
25168 @item sis-queue posix
25169 SiS with delayed comparison and deduplication.
25171 Defaults to @samp{"sis posix"}.
25174 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
25175 Hash format to use in attachment filenames. You can add any text and
25176 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
25177 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
25178 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
25179 Defaults to @samp{"%@{sha1@}"}.
25182 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
25184 Defaults to @samp{100}.
25187 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
25189 Defaults to @samp{1000}.
25192 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
25193 Default VSZ (virtual memory size) limit for service processes.
25194 This is mainly intended to catch and kill processes that leak memory
25195 before they eat up everything.
25196 Defaults to @samp{256000000}.
25199 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
25200 Login user is internally used by login processes. This is the most
25201 untrusted user in Dovecot system. It shouldn't have access to anything
25203 Defaults to @samp{"dovenull"}.
25206 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
25207 Internal user is used by unprivileged processes. It should be
25208 separate from login user, so that login processes can't disturb other
25210 Defaults to @samp{"dovecot"}.
25213 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
25214 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
25215 Defaults to @samp{"required"}.
25218 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
25219 PEM encoded X.509 SSL/TLS certificate (public key).
25220 Defaults to @samp{"</etc/dovecot/default.pem"}.
25223 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
25224 PEM encoded SSL/TLS private key. The key is opened before
25225 dropping root privileges, so keep the key file unreadable by anyone but
25227 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
25230 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
25231 If key file is password protected, give the password here.
25232 Alternatively give it when starting dovecot with -p parameter. Since
25233 this file is often world-readable, you may want to place this setting
25234 instead to a different.
25235 Defaults to @samp{""}.
25238 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
25239 PEM encoded trusted certificate authority. Set this only if you
25240 intend to use @samp{ssl-verify-client-cert? #t}. The file should
25241 contain the CA certificate(s) followed by the matching
25242 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
25243 Defaults to @samp{""}.
25246 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
25247 Require that CRL check succeeds for client certificates.
25248 Defaults to @samp{#t}.
25251 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
25252 Request client to send a certificate. If you also want to require
25253 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
25254 Defaults to @samp{#f}.
25257 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
25258 Which field from certificate to use for username. commonName and
25259 x500UniqueIdentifier are the usual choices. You'll also need to set
25260 @samp{auth-ssl-username-from-cert? #t}.
25261 Defaults to @samp{"commonName"}.
25264 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
25265 Minimum SSL protocol version to accept.
25266 Defaults to @samp{"TLSv1"}.
25269 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
25270 SSL ciphers to use.
25271 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
25274 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
25275 SSL crypto device to use, for valid values run "openssl engine".
25276 Defaults to @samp{""}.
25279 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
25280 Address to use when sending rejection mails.
25281 %d expands to recipient domain.
25282 Defaults to @samp{"postmaster@@%d"}.
25285 @deftypevr {@code{dovecot-configuration} parameter} string hostname
25286 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
25287 and in LMTP replies. Default is the system's real hostname@@domain.
25288 Defaults to @samp{""}.
25291 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
25292 If user is over quota, return with temporary failure instead of
25294 Defaults to @samp{#f}.
25297 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
25298 Binary to use for sending mails.
25299 Defaults to @samp{"/usr/sbin/sendmail"}.
25302 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
25303 If non-empty, send mails via this SMTP host[:port] instead of
25305 Defaults to @samp{""}.
25308 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
25309 Subject: header to use for rejection mails. You can use the same
25310 variables as for @samp{rejection-reason} below.
25311 Defaults to @samp{"Rejected: %s"}.
25314 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
25315 Human readable error message for rejection mails. You can use
25328 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
25331 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
25332 Delimiter character between local-part and detail in email
25334 Defaults to @samp{"+"}.
25337 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
25338 Header where the original recipient address (SMTP's RCPT TO:
25339 address) is taken from if not available elsewhere. With dovecot-lda -a
25340 parameter overrides this. A commonly used header for this is
25342 Defaults to @samp{""}.
25345 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
25346 Should saving a mail to a nonexistent mailbox automatically create
25348 Defaults to @samp{#f}.
25351 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
25352 Should automatically created mailboxes be also automatically
25354 Defaults to @samp{#f}.
25357 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
25358 Maximum IMAP command line length. Some clients generate very long
25359 command lines with huge mailboxes, so you may need to raise this if you
25360 get "Too long argument" or "IMAP command line too large" errors
25362 Defaults to @samp{64000}.
25365 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
25366 IMAP logout format string:
25369 total number of bytes read from client
25371 total number of bytes sent to client.
25373 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
25374 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@}"}.
25377 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
25378 Override the IMAP CAPABILITY response. If the value begins with '+',
25379 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
25380 Defaults to @samp{""}.
25383 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
25384 How long to wait between "OK Still here" notifications when client
25386 Defaults to @samp{"2 mins"}.
25389 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
25390 ID field names and values to send to clients. Using * as the value
25391 makes Dovecot use the default value. The following fields have default
25392 values currently: name, version, os, os-version, support-url,
25394 Defaults to @samp{""}.
25397 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
25398 ID fields sent by client to log. * means everything.
25399 Defaults to @samp{""}.
25402 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
25403 Workarounds for various client bugs:
25406 @item delay-newmail
25407 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
25408 CHECK commands. Some clients ignore them otherwise, for example OSX
25409 Mail (<v2.1). Outlook Express breaks more badly though, without this it
25410 may show user "Message no longer in server" errors. Note that OE6
25411 still breaks even with this workaround if synchronization is set to
25414 @item tb-extra-mailbox-sep
25415 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
25416 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
25417 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
25419 @item tb-lsub-flags
25420 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
25421 This makes Thunderbird realize they aren't selectable and show them
25422 greyed out, instead of only later giving "not selectable" popup error.
25424 Defaults to @samp{()}.
25427 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
25428 Host allowed in URLAUTH URLs sent by client. "*" allows all.
25429 Defaults to @samp{""}.
25433 Whew! Lots of configuration options. The nice thing about it though is
25434 that Guix has a complete interface to Dovecot's configuration
25435 language. This allows not only a nice way to declare configurations,
25436 but also offers reflective capabilities as well: users can write code to
25437 inspect and transform configurations from within Scheme.
25439 However, it could be that you just want to get a @code{dovecot.conf} up
25440 and running. In that case, you can pass an
25441 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
25442 @code{dovecot-service}. As its name indicates, an opaque configuration
25443 does not have easy reflective capabilities.
25445 Available @code{opaque-dovecot-configuration} fields are:
25447 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
25448 The dovecot package.
25451 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
25452 The contents of the @code{dovecot.conf}, as a string.
25455 For example, if your @code{dovecot.conf} is just the empty string, you
25456 could instantiate a dovecot service like this:
25459 (dovecot-service #:config
25460 (opaque-dovecot-configuration
25464 @subsubheading OpenSMTPD Service
25466 @deffn {Scheme Variable} opensmtpd-service-type
25467 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
25468 service, whose value should be an @code{opensmtpd-configuration} object
25469 as in this example:
25472 (service opensmtpd-service-type
25473 (opensmtpd-configuration
25474 (config-file (local-file "./my-smtpd.conf"))))
25478 @deftp {Data Type} opensmtpd-configuration
25479 Data type representing the configuration of opensmtpd.
25482 @item @code{package} (default: @var{opensmtpd})
25483 Package object of the OpenSMTPD SMTP server.
25485 @item @code{config-file} (default: @code{%default-opensmtpd-config-file})
25486 File-like object of the OpenSMTPD configuration file to use. By default
25487 it listens on the loopback network interface, and allows for mail from
25488 users and daemons on the local machine, as well as permitting email to
25489 remote servers. Run @command{man smtpd.conf} for more information.
25491 @item @code{setgid-commands?} (default: @code{#t})
25492 Make the following commands setgid to @code{smtpq} so they can be
25493 executed: @command{smtpctl}, @command{sendmail}, @command{send-mail},
25494 @command{makemap}, @command{mailq}, and @command{newaliases}.
25495 @xref{Setuid Programs}, for more information on setgid programs.
25499 @subsubheading Exim Service
25501 @cindex mail transfer agent (MTA)
25502 @cindex MTA (mail transfer agent)
25505 @deffn {Scheme Variable} exim-service-type
25506 This is the type of the @uref{https://exim.org, Exim} mail transfer
25507 agent (MTA), whose value should be an @code{exim-configuration} object
25508 as in this example:
25511 (service exim-service-type
25512 (exim-configuration
25513 (config-file (local-file "./my-exim.conf"))))
25517 In order to use an @code{exim-service-type} service you must also have a
25518 @code{mail-aliases-service-type} service present in your
25519 @code{operating-system} (even if it has no aliases).
25521 @deftp {Data Type} exim-configuration
25522 Data type representing the configuration of exim.
25525 @item @code{package} (default: @var{exim})
25526 Package object of the Exim server.
25528 @item @code{config-file} (default: @code{#f})
25529 File-like object of the Exim configuration file to use. If its value is
25530 @code{#f} then use the default configuration file from the package
25531 provided in @code{package}. The resulting configuration file is loaded
25532 after setting the @code{exim_user} and @code{exim_group} configuration
25538 @subsubheading Getmail service
25543 @deffn {Scheme Variable} getmail-service-type
25544 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
25545 mail retriever, whose value should be an @code{getmail-configuration}.
25548 Available @code{getmail-configuration} fields are:
25550 @deftypevr {@code{getmail-configuration} parameter} symbol name
25551 A symbol to identify the getmail service.
25553 Defaults to @samp{"unset"}.
25557 @deftypevr {@code{getmail-configuration} parameter} package package
25558 The getmail package to use.
25562 @deftypevr {@code{getmail-configuration} parameter} string user
25563 The user to run getmail as.
25565 Defaults to @samp{"getmail"}.
25569 @deftypevr {@code{getmail-configuration} parameter} string group
25570 The group to run getmail as.
25572 Defaults to @samp{"getmail"}.
25576 @deftypevr {@code{getmail-configuration} parameter} string directory
25577 The getmail directory to use.
25579 Defaults to @samp{"/var/lib/getmail/default"}.
25583 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
25584 The getmail configuration file to use.
25586 Available @code{getmail-configuration-file} fields are:
25588 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
25589 What mail account to retrieve mail from, and how to access that account.
25591 Available @code{getmail-retriever-configuration} fields are:
25593 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
25594 The type of mail retriever to use. Valid values include @samp{passwd}
25597 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
25601 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
25602 Username to login to the mail server with.
25604 Defaults to @samp{unset}.
25608 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
25609 Username to login to the mail server with.
25611 Defaults to @samp{unset}.
25615 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
25616 Port number to connect to.
25618 Defaults to @samp{#f}.
25622 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
25623 Override fields from passwd.
25625 Defaults to @samp{""}.
25629 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
25630 Override fields from passwd.
25632 Defaults to @samp{()}.
25636 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
25637 PEM-formatted key file to use for the TLS negotiation.
25639 Defaults to @samp{""}.
25643 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
25644 PEM-formatted certificate file to use for the TLS negotiation.
25646 Defaults to @samp{""}.
25650 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
25651 CA certificates to use.
25653 Defaults to @samp{""}.
25657 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
25658 Extra retriever parameters.
25660 Defaults to @samp{()}.
25666 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
25667 What to do with retrieved messages.
25669 Available @code{getmail-destination-configuration} fields are:
25671 @deftypevr {@code{getmail-destination-configuration} parameter} string type
25672 The type of mail destination. Valid values include @samp{Maildir},
25673 @samp{Mboxrd} and @samp{MDA_external}.
25675 Defaults to @samp{unset}.
25679 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
25680 The path option for the mail destination. The behaviour depends on the
25683 Defaults to @samp{""}.
25687 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
25688 Extra destination parameters
25690 Defaults to @samp{()}.
25696 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
25699 Available @code{getmail-options-configuration} fields are:
25701 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
25702 If set to @samp{0}, getmail will only print warnings and errors. A
25703 value of @samp{1} means that messages will be printed about retrieving
25704 and deleting messages. If set to @samp{2}, getmail will print messages
25705 about each of its actions.
25707 Defaults to @samp{1}.
25711 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
25712 If true, getmail will retrieve all available messages. Otherwise it
25713 will only retrieve messages it hasn't seen previously.
25715 Defaults to @samp{#t}.
25719 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
25720 If set to true, messages will be deleted from the server after
25721 retrieving and successfully delivering them. Otherwise, messages will
25722 be left on the server.
25724 Defaults to @samp{#f}.
25728 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
25729 Getmail will delete messages this number of days after seeing them, if
25730 they have been delivered. This means messages will be left on the
25731 server this number of days after delivering them. A value of @samp{0}
25732 disabled this feature.
25734 Defaults to @samp{0}.
25738 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
25739 Delete messages larger than this of bytes after retrieving them, even if
25740 the delete and delete-after options are disabled. A value of @samp{0}
25741 disables this feature.
25743 Defaults to @samp{0}.
25747 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
25748 Retrieve messages totalling up to this number of bytes before closing
25749 the session with the server. A value of @samp{0} disables this feature.
25751 Defaults to @samp{0}.
25755 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
25756 Don't retrieve messages larger than this number of bytes. A value of
25757 @samp{0} disables this feature.
25759 Defaults to @samp{0}.
25763 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
25764 If true, getmail will add a Delivered-To header to messages.
25766 Defaults to @samp{#t}.
25770 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
25771 If set, getmail adds a Received header to the messages.
25773 Defaults to @samp{#t}.
25777 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
25778 Getmail will record a log of its actions to the named file. A value of
25779 @samp{""} disables this feature.
25781 Defaults to @samp{""}.
25785 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
25786 If true, getmail will record a log of its actions using the system
25789 Defaults to @samp{#f}.
25793 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
25794 If true, getmail will log information about messages not retrieved and
25795 the reason for not retrieving them, as well as starting and ending
25798 Defaults to @samp{#f}.
25802 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
25803 Extra options to include.
25805 Defaults to @samp{()}.
25813 @deftypevr {@code{getmail-configuration} parameter} list idle
25814 A list of mailboxes that getmail should wait on the server for new mail
25815 notifications. This depends on the server supporting the IDLE
25818 Defaults to @samp{()}.
25822 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
25823 Environment variables to set for getmail.
25825 Defaults to @samp{()}.
25829 @subsubheading Mail Aliases Service
25831 @cindex email aliases
25832 @cindex aliases, for email addresses
25834 @deffn {Scheme Variable} mail-aliases-service-type
25835 This is the type of the service which provides @code{/etc/aliases},
25836 specifying how to deliver mail to users on this system.
25839 (service mail-aliases-service-type
25840 '(("postmaster" "bob")
25841 ("bob" "bob@@example.com" "bob@@example2.com")))
25845 The configuration for a @code{mail-aliases-service-type} service is an
25846 association list denoting how to deliver mail that comes to this
25847 system. Each entry is of the form @code{(alias addresses ...)}, with
25848 @code{alias} specifying the local alias and @code{addresses} specifying
25849 where to deliver this user's mail.
25851 The aliases aren't required to exist as users on the local system. In
25852 the above example, there doesn't need to be a @code{postmaster} entry in
25853 the @code{operating-system}'s @code{user-accounts} in order to deliver
25854 the @code{postmaster} mail to @code{bob} (which subsequently would
25855 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
25857 @subsubheading GNU Mailutils IMAP4 Daemon
25858 @cindex GNU Mailutils IMAP4 Daemon
25860 @deffn {Scheme Variable} imap4d-service-type
25861 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
25862 mailutils, GNU Mailutils Manual}), whose value should be an
25863 @code{imap4d-configuration} object as in this example:
25866 (service imap4d-service-type
25867 (imap4d-configuration
25868 (config-file (local-file "imap4d.conf"))))
25872 @deftp {Data Type} imap4d-configuration
25873 Data type representing the configuration of @command{imap4d}.
25876 @item @code{package} (default: @code{mailutils})
25877 The package that provides @command{imap4d}.
25879 @item @code{config-file} (default: @code{%default-imap4d-config-file})
25880 File-like object of the configuration file to use, by default it will listen
25881 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
25882 Mailutils Manual}, for details.
25887 @subsubheading Radicale Service
25891 @deffn {Scheme Variable} radicale-service-type
25892 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
25893 server whose value should be a @code{radicale-configuration}.
25896 @deftp {Data Type} radicale-configuration
25897 Data type representing the configuration of @command{radicale}.
25900 @item @code{package} (default: @code{radicale})
25901 The package that provides @command{radicale}.
25903 @item @code{config-file} (default: @code{%default-radicale-config-file})
25904 File-like object of the configuration file to use, by default it will listen
25905 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
25906 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
25911 @node Messaging Services
25912 @subsection Messaging Services
25917 The @code{(gnu services messaging)} module provides Guix service
25918 definitions for messaging services. Currently it provides the following
25921 @subsubheading Prosody Service
25923 @deffn {Scheme Variable} prosody-service-type
25924 This is the type for the @uref{https://prosody.im, Prosody XMPP
25925 communication server}. Its value must be a @code{prosody-configuration}
25926 record as in this example:
25929 (service prosody-service-type
25930 (prosody-configuration
25931 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
25934 (int-component-configuration
25935 (hostname "conference.example.net")
25937 (mod-muc (mod-muc-configuration)))))
25940 (virtualhost-configuration
25941 (domain "example.net"))))))
25944 See below for details about @code{prosody-configuration}.
25948 By default, Prosody does not need much configuration. Only one
25949 @code{virtualhosts} field is needed: it specifies the domain you wish
25952 You can perform various sanity checks on the generated configuration
25953 with the @code{prosodyctl check} command.
25955 Prosodyctl will also help you to import certificates from the
25956 @code{letsencrypt} directory so that the @code{prosody} user can access
25957 them. See @url{https://prosody.im/doc/letsencrypt}.
25960 prosodyctl --root cert import /etc/letsencrypt/live
25963 The available configuration parameters follow. Each parameter
25964 definition is preceded by its type; for example, @samp{string-list foo}
25965 indicates that the @code{foo} parameter should be specified as a list of
25966 strings. Types starting with @code{maybe-} denote parameters that won't
25967 show up in @code{prosody.cfg.lua} when their value is left unspecified.
25969 There is also a way to specify the configuration as a string, if you
25970 have an old @code{prosody.cfg.lua} file that you want to port over from
25971 some other system; see the end for more details.
25973 The @code{file-object} type designates either a file-like object
25974 (@pxref{G-Expressions, file-like objects}) or a file name.
25976 @c The following documentation was initially generated by
25977 @c (generate-documentation) in (gnu services messaging). Manually maintained
25978 @c documentation is better, so we shouldn't hesitate to edit below as
25979 @c needed. However if the change you want to make to this documentation
25980 @c can be done in an automated way, it's probably easier to change
25981 @c (generate-documentation) than to make it below and have to deal with
25982 @c the churn as Prosody updates.
25984 Available @code{prosody-configuration} fields are:
25986 @deftypevr {@code{prosody-configuration} parameter} package prosody
25987 The Prosody package.
25990 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
25991 Location of the Prosody data storage directory. See
25992 @url{https://prosody.im/doc/configure}.
25993 Defaults to @samp{"/var/lib/prosody"}.
25996 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
25997 Additional plugin directories. They are searched in all the specified
25998 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
25999 Defaults to @samp{()}.
26002 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
26003 Every virtual host and component needs a certificate so that clients and
26004 servers can securely verify its identity. Prosody will automatically load
26005 certificates/keys from the directory specified here.
26006 Defaults to @samp{"/etc/prosody/certs"}.
26009 @deftypevr {@code{prosody-configuration} parameter} string-list admins
26010 This is a list of accounts that are admins for the server. Note that you
26011 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
26012 @url{https://prosody.im/doc/creating_accounts}.
26013 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
26014 Defaults to @samp{()}.
26017 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
26018 Enable use of libevent for better performance under high load. See
26019 @url{https://prosody.im/doc/libevent}.
26020 Defaults to @samp{#f}.
26023 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
26024 This is the list of modules Prosody will load on startup. It looks for
26025 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
26026 Documentation on modules can be found at:
26027 @url{https://prosody.im/doc/modules}.
26028 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
26031 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
26032 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
26033 should you want to disable them then add them to this list.
26034 Defaults to @samp{()}.
26037 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
26038 Path to a text file where the shared groups are defined. If this path is
26039 empty then @samp{mod_groups} does nothing. See
26040 @url{https://prosody.im/doc/modules/mod_groups}.
26041 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
26044 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
26045 Disable account creation by default, for security. See
26046 @url{https://prosody.im/doc/creating_accounts}.
26047 Defaults to @samp{#f}.
26050 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
26051 These are the SSL/TLS-related settings. Most of them are disabled so to
26052 use Prosody's defaults. If you do not completely understand these options, do
26053 not add them to your config, it is easy to lower the security of your server
26054 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
26056 Available @code{ssl-configuration} fields are:
26058 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
26059 This determines what handshake to use.
26062 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
26063 Path to your private key file.
26066 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
26067 Path to your certificate file.
26070 @deftypevr {@code{ssl-configuration} parameter} file-object capath
26071 Path to directory containing root certificates that you wish Prosody to
26072 trust when verifying the certificates of remote servers.
26073 Defaults to @samp{"/etc/ssl/certs"}.
26076 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
26077 Path to a file containing root certificates that you wish Prosody to trust.
26078 Similar to @code{capath} but with all certificates concatenated together.
26081 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
26082 A list of verification options (these mostly map to OpenSSL's
26083 @code{set_verify()} flags).
26086 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
26087 A list of general options relating to SSL/TLS@. These map to OpenSSL's
26088 @code{set_options()}. For a full list of options available in LuaSec, see the
26092 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
26093 How long a chain of certificate authorities to check when looking for a
26094 trusted root certificate.
26097 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
26098 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
26099 clients, and in what order.
26102 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
26103 A path to a file containing parameters for Diffie-Hellman key exchange. You
26104 can create such a file with:
26105 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
26108 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
26109 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
26110 @samp{"secp384r1"}.
26113 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
26114 A list of ``extra'' verification options.
26117 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
26118 Password for encrypted private keys.
26123 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
26124 Whether to force all client-to-server connections to be encrypted or not.
26125 See @url{https://prosody.im/doc/modules/mod_tls}.
26126 Defaults to @samp{#f}.
26129 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
26130 Set of mechanisms that will never be offered. See
26131 @url{https://prosody.im/doc/modules/mod_saslauth}.
26132 Defaults to @samp{("DIGEST-MD5")}.
26135 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
26136 Whether to force all server-to-server connections to be encrypted or not.
26137 See @url{https://prosody.im/doc/modules/mod_tls}.
26138 Defaults to @samp{#f}.
26141 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
26142 Whether to require encryption and certificate authentication. This
26143 provides ideal security, but requires servers you communicate with to support
26144 encryption AND present valid, trusted certificates. See
26145 @url{https://prosody.im/doc/s2s#security}.
26146 Defaults to @samp{#f}.
26149 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
26150 Many servers don't support encryption or have invalid or self-signed
26151 certificates. You can list domains here that will not be required to
26152 authenticate using certificates. They will be authenticated using DNS@. See
26153 @url{https://prosody.im/doc/s2s#security}.
26154 Defaults to @samp{()}.
26157 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
26158 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
26159 valid certificates for some domains by specifying a list here. See
26160 @url{https://prosody.im/doc/s2s#security}.
26161 Defaults to @samp{()}.
26164 @deftypevr {@code{prosody-configuration} parameter} string authentication
26165 Select the authentication backend to use. The default provider stores
26166 passwords in plaintext and uses Prosody's configured data storage to store the
26167 authentication data. If you do not trust your server please see
26168 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
26169 about using the hashed backend. See also
26170 @url{https://prosody.im/doc/authentication}
26171 Defaults to @samp{"internal_plain"}.
26174 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
26175 Set logging options. Advanced logging configuration is not yet supported
26176 by the Prosody service. See @url{https://prosody.im/doc/logging}.
26177 Defaults to @samp{"*syslog"}.
26180 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
26181 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
26182 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
26185 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
26186 Maximum allowed size of the HTTP body (in bytes).
26189 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
26190 Some modules expose their own URL in various ways. This URL is built
26191 from the protocol, host and port used. If Prosody sits behind a proxy, the
26192 public URL will be @code{http-external-url} instead. See
26193 @url{https://prosody.im/doc/http#external_url}.
26196 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
26197 A host in Prosody is a domain on which user accounts can be created. For
26198 example if you want your users to have addresses like
26199 @samp{"john.smith@@example.com"} then you need to add a host
26200 @samp{"example.com"}. All options in this list will apply only to this host.
26203 The name @emph{virtual} host is used in configuration to avoid confusion with
26204 the actual physical host that Prosody is installed on. A single Prosody
26205 instance can serve many domains, each one defined as a VirtualHost entry in
26206 Prosody's configuration. Conversely a server that hosts a single domain would
26207 have just one VirtualHost entry.
26209 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
26212 Available @code{virtualhost-configuration} fields are:
26214 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:
26215 @deftypevr {@code{virtualhost-configuration} parameter} string domain
26216 Domain you wish Prosody to serve.
26221 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
26222 Components are extra services on a server which are available to clients,
26223 usually on a subdomain of the main server (such as
26224 @samp{"mycomponent.example.com"}). Example components might be chatroom
26225 servers, user directories, or gateways to other protocols.
26227 Internal components are implemented with Prosody-specific plugins. To add an
26228 internal component, you simply fill the hostname field, and the plugin you wish
26229 to use for the component.
26231 See @url{https://prosody.im/doc/components}.
26232 Defaults to @samp{()}.
26234 Available @code{int-component-configuration} fields are:
26236 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:
26237 @deftypevr {@code{int-component-configuration} parameter} string hostname
26238 Hostname of the component.
26241 @deftypevr {@code{int-component-configuration} parameter} string plugin
26242 Plugin you wish to use for the component.
26245 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
26246 Multi-user chat (MUC) is Prosody's module for allowing you to create
26247 hosted chatrooms/conferences for XMPP users.
26249 General information on setting up and using multi-user chatrooms can be found
26250 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
26251 which you should read if you are new to XMPP chatrooms.
26253 See also @url{https://prosody.im/doc/modules/mod_muc}.
26255 Available @code{mod-muc-configuration} fields are:
26257 @deftypevr {@code{mod-muc-configuration} parameter} string name
26258 The name to return in service discovery responses.
26259 Defaults to @samp{"Prosody Chatrooms"}.
26262 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
26263 If @samp{#t}, this will only allow admins to create new chatrooms.
26264 Otherwise anyone can create a room. The value @samp{"local"} restricts room
26265 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
26266 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
26267 restricts to service administrators only.
26268 Defaults to @samp{#f}.
26271 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
26272 Maximum number of history messages that will be sent to the member that has
26273 just joined the room.
26274 Defaults to @samp{20}.
26281 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
26282 External components use XEP-0114, which most standalone components
26283 support. To add an external component, you simply fill the hostname field. See
26284 @url{https://prosody.im/doc/components}.
26285 Defaults to @samp{()}.
26287 Available @code{ext-component-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{ext-component-configuration} parameter} string component-secret
26291 Password which the component will use to log in.
26294 @deftypevr {@code{ext-component-configuration} parameter} string hostname
26295 Hostname of the component.
26300 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
26301 Port(s) Prosody listens on for component connections.
26302 Defaults to @samp{(5347)}.
26305 @deftypevr {@code{prosody-configuration} parameter} string component-interface
26306 Interface Prosody listens on for component connections.
26307 Defaults to @samp{"127.0.0.1"}.
26310 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
26311 Raw content that will be added to the configuration file.
26314 It could be that you just want to get a @code{prosody.cfg.lua}
26315 up and running. In that case, you can pass an
26316 @code{opaque-prosody-configuration} record as the value of
26317 @code{prosody-service-type}. As its name indicates, an opaque configuration
26318 does not have easy reflective capabilities.
26319 Available @code{opaque-prosody-configuration} fields are:
26321 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
26322 The prosody package.
26325 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
26326 The contents of the @code{prosody.cfg.lua} to use.
26329 For example, if your @code{prosody.cfg.lua} is just the empty
26330 string, you could instantiate a prosody service like this:
26333 (service prosody-service-type
26334 (opaque-prosody-configuration
26335 (prosody.cfg.lua "")))
26338 @c end of Prosody auto-generated documentation
26340 @subsubheading BitlBee Service
26342 @cindex IRC (Internet Relay Chat)
26343 @cindex IRC gateway
26344 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
26345 interface to a variety of messaging protocols such as XMPP.
26347 @defvr {Scheme Variable} bitlbee-service-type
26348 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
26349 gateway daemon. Its value is a @code{bitlbee-configuration} (see
26352 To have BitlBee listen on port 6667 on localhost, add this line to your
26356 (service bitlbee-service-type)
26360 @deftp {Data Type} bitlbee-configuration
26361 This is the configuration for BitlBee, with the following fields:
26364 @item @code{interface} (default: @code{"127.0.0.1"})
26365 @itemx @code{port} (default: @code{6667})
26366 Listen on the network interface corresponding to the IP address
26367 specified in @var{interface}, on @var{port}.
26369 When @var{interface} is @code{127.0.0.1}, only local clients can
26370 connect; when it is @code{0.0.0.0}, connections can come from any
26371 networking interface.
26373 @item @code{bitlbee} (default: @code{bitlbee})
26374 The BitlBee package to use.
26376 @item @code{plugins} (default: @code{'()})
26377 List of plugin packages to use---e.g., @code{bitlbee-discord}.
26379 @item @code{extra-settings} (default: @code{""})
26380 Configuration snippet added as-is to the BitlBee configuration file.
26384 @subsubheading Quassel Service
26386 @cindex IRC (Internet Relay Chat)
26387 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
26388 meaning that one or more clients can attach to and detach from the
26391 @defvr {Scheme Variable} quassel-service-type
26392 This is the service type for the @url{https://quassel-irc.org/,Quassel}
26393 IRC backend daemon. Its value is a @code{quassel-configuration}
26397 @deftp {Data Type} quassel-configuration
26398 This is the configuration for Quassel, with the following fields:
26401 @item @code{quassel} (default: @code{quassel})
26402 The Quassel package to use.
26404 @item @code{interface} (default: @code{"::,0.0.0.0"})
26405 @item @code{port} (default: @code{4242})
26406 Listen on the network interface(s) corresponding to the IPv4 or IPv6
26407 interfaces specified in the comma delimited @var{interface}, on
26410 @item @code{loglevel} (default: @code{"Info"})
26411 The level of logging desired. Accepted values are Debug, Info, Warning
26416 @node Telephony Services
26417 @subsection Telephony Services
26419 @cindex telephony, services
26420 The @code{(gnu services telephony)} module contains Guix service
26421 definitions for telephony services. Currently it provides the following
26424 @subsubheading Jami
26426 @cindex jami, service
26428 This section describes how to configure a Jami server that can be used
26429 to host video (or audio) conferences, among other uses. The following
26430 example demonstrates how to specify Jami account archives (backups) to
26431 be provisioned automatically:
26434 (service jami-service-type
26435 (jami-configuration
26437 (list (jami-account
26438 (archive "/etc/jami/unencrypted-account-1.gz"))
26440 (archive "/etc/jami/unencrypted-account-2.gz"))))))
26443 When the accounts field is specified, the Jami account files of the
26444 service found under @file{/var/lib/jami} are recreated every time the
26447 Jami accounts and their corresponding backup archives can be generated
26448 using the @code{jami} or @code{jami-gnome} Jami clients. The accounts
26449 should not be password-protected, but it is wise to ensure their files
26450 are only readable by @samp{root}.
26452 The next example shows how to declare that only some contacts should be
26453 allowed to communicate with a given account:
26456 (service jami-service-type
26457 (jami-configuration
26459 (list (jami-account
26460 (archive "/etc/jami/unencrypted-account-1.gz")
26461 (peer-discovery? #t)
26462 (rendezvous-point? #t)
26464 '("1dbcb0f5f37324228235564b79f2b9737e9a008f"
26465 "2dbcb0f5f37324228235564b79f2b9737e9a008f")))))))
26468 In this mode, only the declared @code{allowed-contacts} can initiate
26469 communication with the Jami account. This can be used, for example,
26470 with rendezvous point accounts to create a private video conferencing
26473 To put the system administrator in full control of the conferences
26474 hosted on their system, the Jami service supports the following actions:
26477 # herd doc jami list-actions
26479 list-account-details
26480 list-banned-contacts
26489 The above actions aim to provide the most valuable actions for
26490 moderation purposes, not to cover the whole Jami API. Users wanting to
26491 interact with the Jami daemon from Guile may be interested in
26492 experimenting with the @code{(gnu build jami-service)} module, which
26493 powers the above Shepherd actions.
26495 @c TODO: This should be auto-generated from the doc already defined on
26496 @c the shepherd-actions themselves in (gnu services telephony).
26497 The @code{add-moderator} and @code{ban-contact} actions accept a contact
26498 @emph{fingerprint} (40 characters long hash) as first argument and an
26499 account fingerprint or username as second argument:
26502 # herd add-moderator jami 1dbcb0f5f37324228235564b79f2b9737e9a008f \
26503 f3345f2775ddfe07a4b0d95daea111d15fbc1199
26505 # herd list-moderators jami
26506 Moderators for account f3345f2775ddfe07a4b0d95daea111d15fbc1199:
26507 - 1dbcb0f5f37324228235564b79f2b9737e9a008f
26511 In the case of @code{ban-contact}, the second username argument is
26512 optional; when omitted, the account is banned from all Jami accounts:
26515 # herd ban-contact jami 1dbcb0f5f37324228235564b79f2b9737e9a008f
26517 # herd list-banned-contacts jami
26518 Banned contacts for account f3345f2775ddfe07a4b0d95daea111d15fbc1199:
26519 - 1dbcb0f5f37324228235564b79f2b9737e9a008f
26523 Banned contacts are also stripped from their moderation privileges.
26525 The @code{disable-account} action allows to completely disconnect an
26526 account from the network, making it unreachable, while
26527 @code{enable-account} does the inverse. They accept a single account
26528 username or fingerprint as first argument:
26531 # herd disable-account jami f3345f2775ddfe07a4b0d95daea111d15fbc1199
26533 # herd list-accounts jami
26534 The following Jami accounts are available:
26535 - f3345f2775ddfe07a4b0d95daea111d15fbc1199 (dummy) [disabled]
26539 The @code{list-account-details} action prints the detailed parameters of
26540 each accounts in the Recutils format, which means the @command{recsel}
26541 command can be used to select accounts of interest (@pxref{Selection
26542 Expressions,,,recutils, GNU recutils manual}). Note that period
26543 characters (@samp{.}) found in the account parameter keys are mapped to
26544 underscores (@samp{_}) in the output, to meet the requirements of the
26545 Recutils format. The following example shows how to print the account
26546 fingerprints for all accounts operating in the rendezvous point mode:
26549 # herd list-account-details jami | \
26550 recsel -p Account.username -e 'Account.rendezVous ~ "true"'
26551 Account_username: f3345f2775ddfe07a4b0d95daea111d15fbc1199
26554 The remaining actions should be self-explanatory.
26556 The complete set of available configuration options is detailed below.
26558 @c TODO: Ideally, the following fragments would be auto-generated at
26559 @c build time, so that they needn't be manually duplicated.
26560 @c Auto-generated via (configuration->documentation 'jami-configuration)
26561 @deftp {Data Type} jami-configuration
26562 Available @code{jami-configuration} fields are:
26565 @item @code{libjami} (default: @code{libjami}) (type: package)
26566 The Jami daemon package to use.
26568 @item @code{dbus} (default: @code{dbus-for-jami}) (type: package)
26569 The D-Bus package to use to start the required D-Bus session.
26571 @item @code{nss-certs} (default: @code{nss-certs}) (type: package)
26572 The nss-certs package to use to provide TLS certificates.
26574 @item @code{enable-logging?} (default: @code{#t}) (type: boolean)
26575 Whether to enable logging to syslog.
26577 @item @code{debug?} (default: @code{#f}) (type: boolean)
26578 Whether to enable debug level messages.
26580 @item @code{auto-answer?} (default: @code{#f}) (type: boolean)
26581 Whether to force automatic answer to incoming calls.
26583 @item @code{accounts} (type: maybe-jami-account-list)
26584 A list of Jami accounts to be (re-)provisioned every time the Jami
26585 daemon service starts. When providing this field, the account
26586 directories under @file{/var/lib/jami/} are recreated every time the
26587 service starts, ensuring a consistent state.
26593 @c Auto-generated via (configuration->documentation 'jami-account)
26594 @deftp {Data Type} jami-account
26595 Available @code{jami-account} fields are:
26598 @item @code{archive} (type: string-or-computed-file)
26599 The account archive (backup) file name of the account. This is used to
26600 provision the account when the service starts. The account archive
26601 should @emph{not} be encrypted. It is highly recommended to make it
26602 readable only to the @samp{root} user (i.e., not in the store), to guard
26603 against leaking the secret key material of the Jami account it contains.
26605 @item @code{allowed-contacts} (type: maybe-account-fingerprint-list)
26606 The list of allowed contacts for the account, entered as their 40
26607 characters long fingerprint. Messages or calls from accounts not in
26608 that list will be rejected. When left specified, the configuration of
26609 the account archive is used as-is with respect to contacts and public
26610 inbound calls/messaging allowance, which typically defaults to allow any
26611 contact to communicate with the account.
26613 @item @code{moderators} (type: maybe-account-fingerprint-list)
26614 The list of contacts that should have moderation privileges (to ban,
26615 mute, etc. other users) in rendezvous conferences, entered as their 40
26616 characters long fingerprint. When left unspecified, the configuration
26617 of the account archive is used as-is with respect to moderation, which
26618 typically defaults to allow anyone to moderate.
26620 @item @code{rendezvous-point?} (type: maybe-boolean)
26621 Whether the account should operate in the rendezvous mode. In this
26622 mode, all the incoming audio/video calls are mixed into a conference.
26623 When left unspecified, the value from the account archive prevails.
26625 @item @code{peer-discovery?} (type: maybe-boolean)
26626 Whether peer discovery should be enabled. Peer discovery is used to
26627 discover other OpenDHT nodes on the local network, which can be useful
26628 to maintain communication between devices on such network even when the
26629 connection to the the Internet has been lost. When left unspecified,
26630 the value from the account archive prevails.
26632 @item @code{bootstrap-hostnames} (type: maybe-string-list)
26633 A list of hostnames or IPs pointing to OpenDHT nodes, that should be
26634 used to initially join the OpenDHT network. When left unspecified, the
26635 value from the account archive prevails.
26637 @item @code{name-server-uri} (type: maybe-string)
26638 The URI of the name server to use, that can be used to retrieve the
26639 account fingerprint for a registered username.
26645 @subsubheading Mumble server
26649 @cindex VoIP server
26650 This section describes how to set up and run a
26651 @uref{https://mumble.info, Mumble} server (formerly known as Murmur).
26653 @deftp {Data Type} mumble-server-configuration
26654 The service type for the Mumble server. An example configuration can
26658 (service mumble-server-service-type
26659 (mumble-server-configuration
26661 "Welcome to this Mumble server running on Guix!")
26662 (cert-required? #t) ;disallow text password logins
26663 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
26664 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
26667 After reconfiguring your system, you can manually set the mumble-server
26669 password with the command that is printed during the activation phase.
26671 It is recommended to register a normal Mumble user account
26672 and grant it admin or moderator rights.
26673 You can use the @code{mumble} client to
26674 login as new normal user, register yourself, and log out.
26675 For the next step login with the name @code{SuperUser} use
26676 the @code{SuperUser} password that you set previously,
26677 and grant your newly registered mumble user administrator or moderator
26678 rights and create some channels.
26680 Available @code{mumble-server-configuration} fields are:
26683 @item @code{package} (default: @code{mumble})
26684 Package that contains @code{bin/mumble-server}.
26686 @item @code{user} (default: @code{"mumble-server"})
26687 User who will run the Mumble-Server server.
26689 @item @code{group} (default: @code{"mumble-server"})
26690 Group of the user who will run the mumble-server server.
26692 @item @code{port} (default: @code{64738})
26693 Port on which the server will listen.
26695 @item @code{welcome-text} (default: @code{""})
26696 Welcome text sent to clients when they connect.
26698 @item @code{server-password} (default: @code{""})
26699 Password the clients have to enter in order to connect.
26701 @item @code{max-users} (default: @code{100})
26702 Maximum of users that can be connected to the server at once.
26704 @item @code{max-user-bandwidth} (default: @code{#f})
26705 Maximum voice traffic a user can send per second.
26707 @item @code{database-file} (default: @code{"/var/lib/mumble-server/db.sqlite"})
26708 File name of the sqlite database.
26709 The service's user will become the owner of the directory.
26711 @item @code{log-file} (default: @code{"/var/log/mumble-server/mumble-server.log"})
26712 File name of the log file.
26713 The service's user will become the owner of the directory.
26715 @item @code{autoban-attempts} (default: @code{10})
26716 Maximum number of logins a user can make in @code{autoban-timeframe}
26717 without getting auto banned for @code{autoban-time}.
26719 @item @code{autoban-timeframe} (default: @code{120})
26720 Timeframe for autoban in seconds.
26722 @item @code{autoban-time} (default: @code{300})
26723 Amount of time in seconds for which a client gets banned
26724 when violating the autoban limits.
26726 @item @code{opus-threshold} (default: @code{100})
26727 Percentage of clients that need to support opus
26728 before switching over to opus audio codec.
26730 @item @code{channel-nesting-limit} (default: @code{10})
26731 How deep channels can be nested at maximum.
26733 @item @code{channelname-regex} (default: @code{#f})
26734 A string in form of a Qt regular expression that channel names must conform to.
26736 @item @code{username-regex} (default: @code{#f})
26737 A string in form of a Qt regular expression that user names must conform to.
26739 @item @code{text-message-length} (default: @code{5000})
26740 Maximum size in bytes that a user can send in one text chat message.
26742 @item @code{image-message-length} (default: @code{(* 128 1024)})
26743 Maximum size in bytes that a user can send in one image message.
26745 @item @code{cert-required?} (default: @code{#f})
26746 If it is set to @code{#t} clients that use weak password authentication
26747 will not be accepted. Users must have completed the certificate wizard to join.
26749 @item @code{remember-channel?} (default: @code{#f})
26750 Should mumble-server remember the last channel each user was in when
26751 they disconnected and put them into the remembered channel when they
26754 @item @code{allow-html?} (default: @code{#f})
26755 Should html be allowed in text messages, user comments, and channel descriptions.
26757 @item @code{allow-ping?} (default: @code{#f})
26758 Setting to true exposes the current user count, the maximum user count, and
26759 the server's maximum bandwidth per client to unauthenticated users. In the
26760 Mumble client, this information is shown in the Connect dialog.
26762 Disabling this setting will prevent public listing of the server.
26764 @item @code{bonjour?} (default: @code{#f})
26765 Should the server advertise itself in the local network through the bonjour protocol.
26767 @item @code{send-version?} (default: @code{#f})
26768 Should the mumble-server server version be exposed in ping requests.
26770 @item @code{log-days} (default: @code{31})
26771 Mumble also stores logs in the database, which are accessible via RPC.
26772 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
26773 or -1 to disable logging to the database.
26775 @item @code{obfuscate-ips?} (default: @code{#t})
26776 Should logged ips be obfuscated to protect the privacy of users.
26778 @item @code{ssl-cert} (default: @code{#f})
26779 File name of the SSL/TLS certificate used for encrypted connections.
26782 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
26784 @item @code{ssl-key} (default: @code{#f})
26785 Filepath to the ssl private key used for encrypted connections.
26787 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
26790 @item @code{ssl-dh-params} (default: @code{#f})
26791 File name of a PEM-encoded file with Diffie-Hellman parameters
26792 for the SSL/TLS encryption. Alternatively you set it to
26793 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
26794 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
26796 @item @code{ssl-ciphers} (default: @code{#f})
26797 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
26800 This option is specified using
26801 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
26802 OpenSSL cipher list notation}.
26804 It is recommended that you try your cipher string using
26805 'openssl ciphers <string>' before setting it here, to get a feel for
26806 which cipher suites you will get.
26807 After setting this option, it is recommend that you inspect your Mumble
26808 server log to ensure that Mumble is using the cipher suites that you
26812 Changing this option may impact the backwards compatibility of your
26813 Mumble-Server server, and can remove the ability for older Mumble clients to be able to connect to it.
26816 @item @code{public-registration} (default: @code{#f})
26817 Must be a @code{<mumble-server-public-registration-configuration>}
26818 record or @code{#f}.
26820 You can optionally register your server in the public server list that the
26821 @code{mumble} client shows on startup.
26822 You cannot register your server if you have set a @code{server-password},
26823 or set @code{allow-ping} to @code{#f}.
26825 It might take a few hours until it shows up in the public list.
26827 @item @code{file} (default: @code{#f})
26828 Optional alternative override for this configuration.
26832 @deftp {Data Type} mumble-server-public-registration-configuration
26833 Configuration for public registration of a mumble-server service.
26837 This is a display name for your server. Not to be confused with the hostname.
26839 @item @code{password}
26840 A password to identify your registration.
26841 Subsequent updates will need the same password. Don't lose your password.
26844 This should be a @code{http://} or @code{https://} link to your web
26847 @item @code{hostname} (default: @code{#f})
26848 By default your server will be listed by its IP address.
26849 If it is set your server will be linked by this host name instead.
26853 @quotation Deprecation notice
26854 Due to historical reasons, all of the above @code{mumble-server-}
26855 procedures are also exported with the @code{murmur-} prefix.
26856 It is recommended that you switch to using @code{mumble-server-}
26860 @node File-Sharing Services
26861 @subsection File-Sharing Services
26863 The @code{(gnu services file-sharing)} module provides services that
26864 assist with transferring files over peer-to-peer file-sharing networks.
26866 @subsubheading Transmission Daemon Service
26868 @uref{https://transmissionbt.com/, Transmission} is a flexible
26869 BitTorrent client that offers a variety of graphical and command-line
26870 interfaces. A @code{transmission-daemon-service-type} service provides
26871 Transmission's headless variant, @command{transmission-daemon}, as a
26872 system service, allowing users to share files via BitTorrent even when
26873 they are not logged in.
26875 @deffn {Scheme Variable} transmission-daemon-service-type
26876 The service type for the Transmission Daemon BitTorrent client. Its
26877 value must be a @code{transmission-daemon-configuration} object as in
26881 (service transmission-daemon-service-type
26882 (transmission-daemon-configuration
26883 ;; Restrict access to the RPC ("control") interface
26884 (rpc-authentication-required? #t)
26885 (rpc-username "transmission")
26887 (transmission-password-hash
26888 "transmission" ; desired password
26889 "uKd1uMs9")) ; arbitrary salt value
26891 ;; Accept requests from this and other hosts on the
26893 (rpc-whitelist-enabled? #t)
26894 (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
26896 ;; Limit bandwidth use during work hours
26897 (alt-speed-down (* 1024 2)) ; 2 MB/s
26898 (alt-speed-up 512) ; 512 kB/s
26900 (alt-speed-time-enabled? #t)
26901 (alt-speed-time-day 'weekdays)
26902 (alt-speed-time-begin
26903 (+ (* 60 8) 30)) ; 8:30 am
26904 (alt-speed-time-end
26905 (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
26909 Once the service is started, users can interact with the daemon through
26910 its Web interface (at @code{http://localhost:9091/}) or by using the
26911 @command{transmission-remote} command-line tool, available in the
26912 @code{transmission} package. (Emacs users may want to also consider the
26913 @code{emacs-transmission} package.) Both communicate with the daemon
26914 through its remote procedure call (RPC) interface, which by default is
26915 available to all users on the system; you may wish to change this by
26916 assigning values to the @code{rpc-authentication-required?},
26917 @code{rpc-username} and @code{rpc-password} settings, as shown in the
26918 example above and documented further below.
26920 The value for @code{rpc-password} must be a password hash of the type
26921 generated and used by Transmission clients. This can be copied verbatim
26922 from an existing @file{settings.json} file, if another Transmission
26923 client is already being used. Otherwise, the
26924 @code{transmission-password-hash} and @code{transmission-random-salt}
26925 procedures provided by this module can be used to obtain a suitable hash
26928 @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
26929 Returns a string containing the result of hashing @var{password}
26930 together with @var{salt}, in the format recognized by Transmission
26931 clients for their @code{rpc-password} configuration setting.
26933 @var{salt} must be an eight-character string. The
26934 @code{transmission-random-salt} procedure can be used to generate a
26935 suitable salt value at random.
26938 @deffn {Scheme Procedure} transmission-random-salt
26939 Returns a string containing a random, eight-character salt value of the
26940 type generated and used by Transmission clients, suitable for passing to
26941 the @code{transmission-password-hash} procedure.
26944 These procedures are accessible from within a Guile REPL started with
26945 the @command{guix repl} command (@pxref{Invoking guix repl}). This is
26946 useful for obtaining a random salt value to provide as the second
26947 parameter to `transmission-password-hash`, as in this example session:
26951 scheme@@(guix-user)> ,use (gnu services file-sharing)
26952 scheme@@(guix-user)> (transmission-random-salt)
26956 Alternatively, a complete password hash can generated in a single step:
26959 scheme@@(guix-user)> (transmission-password-hash "transmission"
26960 (transmission-random-salt))
26961 $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
26964 The resulting string can be used as-is for the value of
26965 @code{rpc-password}, allowing the password to be kept hidden even in the
26966 operating-system configuration.
26968 Torrent files downloaded by the daemon are directly accessible only to
26969 users in the ``transmission'' user group, who receive read-only access
26970 to the directory specified by the @code{download-dir} configuration
26971 setting (and also the directory specified by @code{incomplete-dir}, if
26972 @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
26973 moved to another directory or deleted altogether using
26974 @command{transmission-remote} with its @code{--move} and
26975 @code{--remove-and-delete} options.
26977 If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
26978 the ``transmission'' group are able also to place @file{.torrent} files
26979 in the directory specified by @code{watch-dir} to have the corresponding
26980 torrents added by the daemon. (The @code{trash-original-torrent-files?}
26981 setting controls whether the daemon deletes these files after processing
26984 Some of the daemon's configuration settings can be changed temporarily
26985 by @command{transmission-remote} and similar tools. To undo these
26986 changes, use the service's @code{reload} action to have the daemon
26987 reload its settings from disk:
26990 # herd reload transmission-daemon
26993 The full set of available configuration settings is defined by the
26994 @code{transmission-daemon-configuration} data type.
26996 @deftp {Data Type} transmission-daemon-configuration
26997 The data type representing configuration settings for Transmission
26998 Daemon. These correspond directly to the settings recognized by
26999 Transmission clients in their @file{settings.json} file.
27002 @c The following documentation was initially generated by
27003 @c (generate-transmission-daemon-documentation) in (gnu services
27004 @c file-sharing). Manually maintained documentation is better, so we
27005 @c shouldn't hesitate to edit below as needed. However if the change
27006 @c you want to make to this documentation can be done in an automated
27007 @c way, it's probably easier to change (generate-documentation) than to
27008 @c make it below and have to deal with the churn as Transmission Daemon
27011 @c %start of fragment
27013 Available @code{transmission-daemon-configuration} fields are:
27015 @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
27016 The Transmission package to use.
27020 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
27021 The period, in seconds, to wait when stopping the service for
27022 @command{transmission-daemon} to exit before killing its process. This
27023 allows the daemon time to complete its housekeeping and send a final
27024 update to trackers as it shuts down. On slow hosts, or hosts with a
27025 slow network connection, this value may need to be increased.
27027 Defaults to @samp{10}.
27031 @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
27032 The directory to which torrent files are downloaded.
27034 Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
27038 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
27039 If @code{#t}, files will be held in @code{incomplete-dir} while their
27040 torrent is being downloaded, then moved to @code{download-dir} once the
27041 torrent is complete. Otherwise, files for all torrents (including those
27042 still being downloaded) will be placed in @code{download-dir}.
27044 Defaults to @samp{#f}.
27048 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
27049 The directory in which files from incompletely downloaded torrents will
27050 be held when @code{incomplete-dir-enabled?} is @code{#t}.
27052 Defaults to @samp{disabled}.
27056 @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
27057 The file mode creation mask used for downloaded files. (See the
27058 @command{umask} man page for more information.)
27060 Defaults to @samp{18}.
27064 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
27065 When @code{#t}, ``.part'' is appended to the name of partially
27068 Defaults to @samp{#t}.
27072 @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
27073 The mode by which space should be preallocated for downloaded files, one
27074 of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
27075 Specifying @code{full} will minimize disk fragmentation at a cost to
27076 file-creation speed.
27078 Defaults to @samp{fast}.
27082 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
27083 If @code{#t}, the directory specified by @code{watch-dir} will be
27084 watched for new @file{.torrent} files and the torrents they describe
27085 added automatically (and the original files removed, if
27086 @code{trash-original-torrent-files?} is @code{#t}).
27088 Defaults to @samp{#f}.
27092 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
27093 The directory to be watched for @file{.torrent} files indicating new
27094 torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
27096 Defaults to @samp{disabled}.
27100 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
27101 When @code{#t}, @file{.torrent} files will be deleted from the watch
27102 directory once their torrent has been added (see
27103 @code{watch-directory-enabled?}).
27105 Defaults to @samp{#f}.
27109 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
27110 When @code{#t}, the daemon's download speed will be limited to the rate
27111 specified by @code{speed-limit-down}.
27113 Defaults to @samp{#f}.
27117 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
27118 The default global-maximum download speed, in kilobytes per second.
27120 Defaults to @samp{100}.
27124 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
27125 When @code{#t}, the daemon's upload speed will be limited to the rate
27126 specified by @code{speed-limit-up}.
27128 Defaults to @samp{#f}.
27132 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
27133 The default global-maximum upload speed, in kilobytes per second.
27135 Defaults to @samp{100}.
27139 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
27140 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
27141 @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
27142 @code{speed-limit-up}, if they are enabled) to constrain the daemon's
27143 bandwidth usage. This can be scheduled to occur automatically at
27144 certain times during the week; see @code{alt-speed-time-enabled?}.
27146 Defaults to @samp{#f}.
27150 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
27151 The alternate global-maximum download speed, in kilobytes per second.
27153 Defaults to @samp{50}.
27157 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
27158 The alternate global-maximum upload speed, in kilobytes per second.
27160 Defaults to @samp{50}.
27164 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
27165 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
27166 @code{alt-speed-up} will be enabled automatically during the periods
27167 specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
27168 @code{alt-time-speed-end}.
27170 Defaults to @samp{#f}.
27174 @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
27175 The days of the week on which the alternate-speed schedule should be
27176 used, specified either as a list of days (@code{sunday}, @code{monday},
27177 and so on) or using one of the symbols @code{weekdays}, @code{weekends}
27180 Defaults to @samp{all}.
27184 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
27185 The time of day at which to enable the alternate speed limits, expressed
27186 as a number of minutes since midnight.
27188 Defaults to @samp{540}.
27192 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
27193 The time of day at which to disable the alternate speed limits,
27194 expressed as a number of minutes since midnight.
27196 Defaults to @samp{1020}.
27200 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
27201 The IP address at which to listen for peer connections, or ``0.0.0.0''
27202 to listen at all available IP addresses.
27204 Defaults to @samp{"0.0.0.0"}.
27208 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
27209 The IPv6 address at which to listen for peer connections, or ``::'' to
27210 listen at all available IPv6 addresses.
27212 Defaults to @samp{"::"}.
27216 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
27217 If @code{#t}, when the daemon starts it will select a port at random on
27218 which to listen for peer connections, from the range specified
27219 (inclusively) by @code{peer-port-random-low} and
27220 @code{peer-port-random-high}. Otherwise, it listens on the port
27221 specified by @code{peer-port}.
27223 Defaults to @samp{#f}.
27227 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
27228 The lowest selectable port number when @code{peer-port-random-on-start?}
27231 Defaults to @samp{49152}.
27235 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
27236 The highest selectable port number when @code{peer-port-random-on-start}
27239 Defaults to @samp{65535}.
27243 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
27244 The port on which to listen for peer connections when
27245 @code{peer-port-random-on-start?} is @code{#f}.
27247 Defaults to @samp{51413}.
27251 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
27252 If @code{#t}, the daemon will attempt to configure port-forwarding on an
27253 upstream gateway automatically using @acronym{UPnP} and
27256 Defaults to @samp{#t}.
27260 @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
27261 The encryption preference for peer connections, one of
27262 @code{prefer-unencrypted-connections},
27263 @code{prefer-encrypted-connections} or
27264 @code{require-encrypted-connections}.
27266 Defaults to @samp{prefer-encrypted-connections}.
27270 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
27271 The TCP congestion-control algorithm to use for peer connections,
27272 specified using a string recognized by the operating system in calls to
27273 @code{setsockopt}. When left unspecified, the operating-system default
27276 Note that on GNU/Linux systems, the kernel must be configured to allow
27277 processes to use a congestion-control algorithm not in the default set;
27278 otherwise, it will deny these requests with ``Operation not permitted''.
27279 To see which algorithms are available on your system and which are
27280 currently permitted for use, look at the contents of the files
27281 @file{tcp_available_congestion_control} and
27282 @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
27285 As an example, to have Transmission Daemon use
27286 @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
27287 congestion-control algorithm}, you'll need to modify your kernel
27288 configuration to build in support for the algorithm, then update your
27289 operating-system configuration to allow its use by adding a
27290 @code{sysctl-service-type} service (or updating the existing one's
27291 configuration) with lines like the following:
27294 (service sysctl-service-type
27295 (sysctl-configuration
27297 ("net.ipv4.tcp_allowed_congestion_control" .
27298 "reno cubic lp"))))
27301 The Transmission Daemon configuration can then be updated with
27304 (peer-congestion-algorithm "lp")
27307 and the system reconfigured to have the changes take effect.
27309 Defaults to @samp{disabled}.
27313 @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
27314 The type of service to request in outgoing @acronym{TCP} packets, one of
27315 @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
27316 @code{reliability}.
27318 Defaults to @samp{default}.
27322 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
27323 The global limit on the number of connected peers.
27325 Defaults to @samp{200}.
27329 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
27330 The per-torrent limit on the number of connected peers.
27332 Defaults to @samp{50}.
27336 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
27337 The maximum number of peers to which the daemon will upload data
27338 simultaneously for each torrent.
27340 Defaults to @samp{14}.
27344 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
27345 The maximum lifespan, in hours, of the peer ID associated with each
27346 public torrent before it is regenerated.
27348 Defaults to @samp{6}.
27352 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
27353 When @code{#t}, the daemon will ignore peers mentioned in the blocklist
27354 it has most recently downloaded from @code{blocklist-url}.
27356 Defaults to @samp{#f}.
27360 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
27361 The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
27362 @file{.dat} format) to be periodically downloaded and applied when
27363 @code{blocklist-enabled?} is @code{#t}.
27365 Defaults to @samp{disabled}.
27369 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
27370 If @code{#t}, the daemon will be limited to downloading at most
27371 @code{download-queue-size} non-stalled torrents simultaneously.
27373 Defaults to @samp{#t}.
27377 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
27378 The size of the daemon's download queue, which limits the number of
27379 non-stalled torrents it will download at any one time when
27380 @code{download-queue-enabled?} is @code{#t}.
27382 Defaults to @samp{5}.
27386 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
27387 If @code{#t}, the daemon will be limited to seeding at most
27388 @code{seed-queue-size} non-stalled torrents simultaneously.
27390 Defaults to @samp{#f}.
27394 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
27395 The size of the daemon's seed queue, which limits the number of
27396 non-stalled torrents it will seed at any one time when
27397 @code{seed-queue-enabled?} is @code{#t}.
27399 Defaults to @samp{10}.
27403 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
27404 When @code{#t}, the daemon will consider torrents for which it has not
27405 shared data in the past @code{queue-stalled-minutes} minutes to be
27406 stalled and not count them against its @code{download-queue-size} and
27407 @code{seed-queue-size} limits.
27409 Defaults to @samp{#t}.
27413 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
27414 The maximum period, in minutes, a torrent may be idle before it is
27415 considered to be stalled, when @code{queue-stalled-enabled?} is
27418 Defaults to @samp{30}.
27422 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
27423 When @code{#t}, a torrent being seeded will automatically be paused once
27424 it reaches the ratio specified by @code{ratio-limit}.
27426 Defaults to @samp{#f}.
27430 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
27431 The ratio at which a torrent being seeded will be paused, when
27432 @code{ratio-limit-enabled?} is @code{#t}.
27434 Defaults to @samp{2.0}.
27438 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
27439 When @code{#t}, a torrent being seeded will automatically be paused once
27440 it has been idle for @code{idle-seeding-limit} minutes.
27442 Defaults to @samp{#f}.
27446 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
27447 The maximum period, in minutes, a torrent being seeded may be idle
27448 before it is paused, when @code{idle-seeding-limit-enabled?} is
27451 Defaults to @samp{30}.
27455 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
27456 Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
27457 hash table (@acronym{DHT}) protocol}, which supports the use of
27458 trackerless torrents.
27460 Defaults to @samp{#t}.
27464 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
27465 Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
27466 peer discovery} (@acronym{LPD}), which allows the discovery of peers on
27467 the local network and may reduce the amount of data sent over the public
27470 Defaults to @samp{#f}.
27474 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
27475 Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
27476 (@acronym{PEX}), which reduces the daemon's reliance on external
27477 trackers and may improve its performance.
27479 Defaults to @samp{#t}.
27483 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
27484 Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
27485 transport protocol} (@acronym{uTP}), which aims to reduce the impact of
27486 BitTorrent traffic on other users of the local network while maintaining
27487 full utilization of the available bandwidth.
27489 Defaults to @samp{#t}.
27493 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
27494 If @code{#t}, enable the remote procedure call (@acronym{RPC})
27495 interface, which allows remote control of the daemon via its Web
27496 interface, the @command{transmission-remote} command-line client, and
27499 Defaults to @samp{#t}.
27503 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
27504 The IP address at which to listen for @acronym{RPC} connections, or
27505 ``0.0.0.0'' to listen at all available IP addresses.
27507 Defaults to @samp{"0.0.0.0"}.
27511 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
27512 The port on which to listen for @acronym{RPC} connections.
27514 Defaults to @samp{9091}.
27518 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
27519 The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
27521 Defaults to @samp{"/transmission/"}.
27525 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
27526 When @code{#t}, clients must authenticate (see @code{rpc-username} and
27527 @code{rpc-password}) when using the @acronym{RPC} interface. Note this
27528 has the side effect of disabling host-name whitelisting (see
27529 @code{rpc-host-whitelist-enabled?}.
27531 Defaults to @samp{#f}.
27535 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
27536 The username required by clients to access the @acronym{RPC} interface
27537 when @code{rpc-authentication-required?} is @code{#t}.
27539 Defaults to @samp{disabled}.
27543 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
27544 The password required by clients to access the @acronym{RPC} interface
27545 when @code{rpc-authentication-required?} is @code{#t}. This must be
27546 specified using a password hash in the format recognized by Transmission
27547 clients, either copied from an existing @file{settings.json} file or
27548 generated using the @code{transmission-password-hash} procedure.
27550 Defaults to @samp{disabled}.
27554 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
27555 When @code{#t}, @acronym{RPC} requests will be accepted only when they
27556 originate from an address specified in @code{rpc-whitelist}.
27558 Defaults to @samp{#t}.
27562 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
27563 The list of IP and IPv6 addresses from which @acronym{RPC} requests will
27564 be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
27565 may be specified using @samp{*}.
27567 Defaults to @samp{("127.0.0.1" "::1")}.
27571 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
27572 When @code{#t}, @acronym{RPC} requests will be accepted only when they
27573 are addressed to a host named in @code{rpc-host-whitelist}. Note that
27574 requests to ``localhost'' or ``localhost.'', or to a numeric address,
27575 are always accepted regardless of these settings.
27577 Note also this functionality is disabled when
27578 @code{rpc-authentication-required?} is @code{#t}.
27580 Defaults to @samp{#t}.
27584 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
27585 The list of host names recognized by the @acronym{RPC} server when
27586 @code{rpc-host-whitelist-enabled?} is @code{#t}.
27588 Defaults to @samp{()}.
27592 @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
27593 The minimum severity level of messages to be logged (to
27594 @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
27595 logging), @code{error}, @code{info} and @code{debug}.
27597 Defaults to @samp{info}.
27601 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
27602 When @code{#t}, torrents are started as soon as they are added;
27603 otherwise, they are added in ``paused'' state.
27605 Defaults to @samp{#t}.
27609 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
27610 When @code{#t}, the script specified by
27611 @code{script-torrent-done-filename} will be invoked each time a torrent
27614 Defaults to @samp{#f}.
27618 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
27619 A file name or file-like object specifying a script to run each time a
27620 torrent completes, when @code{script-torrent-done-enabled?} is
27623 Defaults to @samp{disabled}.
27627 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
27628 When @code{#t}, the daemon will scrape trackers for a torrent even when
27629 the torrent is paused.
27631 Defaults to @samp{#t}.
27635 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
27636 The amount of memory, in megabytes, to allocate for the daemon's
27637 in-memory cache. A larger value may increase performance by reducing
27638 the frequency of disk I/O.
27640 Defaults to @samp{4}.
27644 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
27645 When @code{#t}, the daemon will try to improve I/O performance by
27646 hinting to the operating system which data is likely to be read next
27647 from disk to satisfy requests from peers.
27649 Defaults to @samp{#t}.
27654 @c %end of fragment
27658 @node Monitoring Services
27659 @subsection Monitoring Services
27661 @subsubheading Tailon Service
27663 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
27664 viewing and searching log files.
27666 The following example will configure the service with default values.
27667 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
27670 (service tailon-service-type)
27673 The following example customises more of the Tailon configuration,
27674 adding @command{sed} to the list of allowed commands.
27677 (service tailon-service-type
27678 (tailon-configuration
27680 (tailon-configuration-file
27681 (allowed-commands '("tail" "grep" "awk" "sed"))))))
27685 @deftp {Data Type} tailon-configuration
27686 Data type representing the configuration of Tailon.
27687 This type has the following parameters:
27690 @item @code{config-file} (default: @code{(tailon-configuration-file)})
27691 The configuration file to use for Tailon. This can be set to a
27692 @dfn{tailon-configuration-file} record value, or any gexp
27693 (@pxref{G-Expressions}).
27695 For example, to instead use a local file, the @code{local-file} function
27699 (service tailon-service-type
27700 (tailon-configuration
27701 (config-file (local-file "./my-tailon.conf"))))
27704 @item @code{package} (default: @code{tailon})
27705 The tailon package to use.
27710 @deftp {Data Type} tailon-configuration-file
27711 Data type representing the configuration options for Tailon.
27712 This type has the following parameters:
27715 @item @code{files} (default: @code{(list "/var/log")})
27716 List of files to display. The list can include strings for a single file
27717 or directory, or a list, where the first item is the name of a
27718 subsection, and the remaining items are the files or directories in that
27721 @item @code{bind} (default: @code{"localhost:8080"})
27722 Address and port to which Tailon should bind on.
27724 @item @code{relative-root} (default: @code{#f})
27725 URL path to use for Tailon, set to @code{#f} to not use a path.
27727 @item @code{allow-transfers?} (default: @code{#t})
27728 Allow downloading the log files in the web interface.
27730 @item @code{follow-names?} (default: @code{#t})
27731 Allow tailing of not-yet existent files.
27733 @item @code{tail-lines} (default: @code{200})
27734 Number of lines to read initially from each file.
27736 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
27737 Commands to allow running. By default, @code{sed} is disabled.
27739 @item @code{debug?} (default: @code{#f})
27740 Set @code{debug?} to @code{#t} to show debug messages.
27742 @item @code{wrap-lines} (default: @code{#t})
27743 Initial line wrapping state in the web interface. Set to @code{#t} to
27744 initially wrap lines (the default), or to @code{#f} to initially not
27747 @item @code{http-auth} (default: @code{#f})
27748 HTTP authentication type to use. Set to @code{#f} to disable
27749 authentication (the default). Supported values are @code{"digest"} or
27752 @item @code{users} (default: @code{#f})
27753 If HTTP authentication is enabled (see @code{http-auth}), access will be
27754 restricted to the credentials provided here. To configure users, use a
27755 list of pairs, where the first element of the pair is the username, and
27756 the 2nd element of the pair is the password.
27759 (tailon-configuration-file
27760 (http-auth "basic")
27761 (users '(("user1" . "password1")
27762 ("user2" . "password2"))))
27769 @subsubheading Darkstat Service
27771 Darkstat is a packet sniffer that captures network traffic, calculates
27772 statistics about usage, and serves reports over HTTP.
27774 @defvar {Scheme Variable} darkstat-service-type
27775 This is the service type for the
27776 @uref{https://unix4lyfe.org/darkstat/, darkstat}
27777 service, its value must be a @code{darkstat-configuration} record as in
27781 (service darkstat-service-type
27782 (darkstat-configuration
27783 (interface "eno1")))
27787 @deftp {Data Type} darkstat-configuration
27788 Data type representing the configuration of @command{darkstat}.
27791 @item @code{package} (default: @code{darkstat})
27792 The darkstat package to use.
27794 @item @code{interface}
27795 Capture traffic on the specified network interface.
27797 @item @code{port} (default: @code{"667"})
27798 Bind the web interface to the specified port.
27800 @item @code{bind-address} (default: @code{"127.0.0.1"})
27801 Bind the web interface to the specified address.
27803 @item @code{base} (default: @code{"/"})
27804 Specify the path of the base URL@. This can be useful if
27805 @command{darkstat} is accessed via a reverse proxy.
27810 @anchor{prometheus-node-exporter}
27811 @subsubheading Prometheus Node Exporter Service
27812 @cindex prometheus-node-exporter
27814 The Prometheus ``node exporter'' makes hardware and operating system statistics
27815 provided by the Linux kernel available for the Prometheus monitoring system.
27816 This service should be deployed on all physical nodes and virtual machines,
27817 where monitoring these statistics is desirable.
27819 @defvar {Scheme variable} prometheus-node-exporter-service-type
27820 This is the service type for the
27821 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
27822 service, its value must be a @code{prometheus-node-exporter-configuration}.
27825 (service prometheus-node-exporter-service-type)
27829 @deftp {Data Type} prometheus-node-exporter-configuration
27830 Data type representing the configuration of @command{node_exporter}.
27833 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
27834 The prometheus-node-exporter package to use.
27836 @item @code{web-listen-address} (default: @code{":9100"})
27837 Bind the web interface to the specified address.
27839 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
27840 This directory can be used to export metrics specific to this machine.
27841 Files containing metrics in the text format, with the filename ending in
27842 @code{.prom} should be placed in this directory.
27844 @item @code{extra-options} (default: @code{'()})
27845 Extra options to pass to the Prometheus node exporter.
27850 @subsubheading Zabbix server
27851 @cindex zabbix zabbix-server
27852 Zabbix is a high performance monitoring system that can collect data from a
27853 variety of sources and provide the results in a web-based interface. Alerting
27854 and reporting is built-in, as well as @dfn{templates} for common operating
27855 system metrics such as network utilization, CPU load, and disk space consumption.
27857 This service provides the central Zabbix monitoring service; you also need
27858 @ref{zabbix-front-end,@code{zabbix-front-end-service-type}} to configure Zabbix
27859 and display results, and optionally @ref{zabbix-agent,
27860 @code{zabbix-agent-service-type}} on machines that should be monitored (other
27861 data sources are supported, such as @ref{prometheus-node-exporter,
27862 Prometheus Node Exporter}).
27864 @defvar {Scheme variable} zabbix-server-service-type
27865 This is the service type for the Zabbix server service. Its value must be a
27866 @code{zabbix-server-configuration} record, shown below.
27869 @c %start of fragment
27871 @deftp {Data Type} zabbix-server-configuration
27872 Available @code{zabbix-server-configuration} fields are:
27875 @item @code{zabbix-server} (default: @code{zabbix-server}) (type: file-like)
27876 The zabbix-server package.
27878 @item @code{user} (default: @code{"zabbix"}) (type: string)
27879 User who will run the Zabbix server.
27881 @item @code{group} (default: @code{"zabbix"}) (type: group)
27882 Group who will run the Zabbix server.
27884 @item @code{db-host} (default: @code{"127.0.0.1"}) (type: string)
27885 Database host name.
27887 @item @code{db-name} (default: @code{"zabbix"}) (type: string)
27890 @item @code{db-user} (default: @code{"zabbix"}) (type: string)
27893 @item @code{db-password} (default: @code{""}) (type: string)
27894 Database password. Please, use @code{include-files} with
27895 @code{DBPassword=SECRET} inside a specified file instead.
27897 @item @code{db-port} (default: @code{5432}) (type: number)
27900 @item @code{log-type} (default: @code{""}) (type: string)
27901 Specifies where log messages are written to:
27905 @item @code{system} - syslog.
27907 @item @code{file} - file specified with @code{log-file} parameter.
27909 @item @code{console} - standard output.
27913 @item @code{log-file} (default: @code{"/var/log/zabbix/server.log"}) (type: string)
27914 Log file name for @code{log-type} @code{file} parameter.
27916 @item @code{pid-file} (default: @code{"/var/run/zabbix/zabbix_server.pid"}) (type: string)
27919 @item @code{ssl-ca-location} (default: @code{"/etc/ssl/certs/ca-certificates.crt"}) (type: string)
27920 The location of certificate authority (CA) files for SSL server
27921 certificate verification.
27923 @item @code{ssl-cert-location} (default: @code{"/etc/ssl/certs"}) (type: string)
27924 Location of SSL client certificates.
27926 @item @code{extra-options} (default: @code{""}) (type: extra-options)
27927 Extra options will be appended to Zabbix server configuration file.
27929 @item @code{include-files} (default: @code{()}) (type: include-files)
27930 You may include individual files or all files in a directory in the
27931 configuration file.
27938 @c %end of fragment
27940 @anchor{zabbix-agent}
27941 @subsubheading Zabbix agent
27942 @cindex zabbix zabbix-agent
27944 The Zabbix agent gathers information about the running system for the Zabbix
27945 monitoring server. It has a variety of built-in checks, and can be extended
27947 @uref{https://www.zabbix.com/documentation/current/en/manual/config/items/userparameters,
27948 @dfn{user parameters}}.
27950 @defvar {Scheme variable} zabbix-agent-service-type
27951 This is the service type for the Zabbix agent service. Its value must be a
27952 @code{zabbix-agent-configuration} record, shown below.
27955 @c %start of fragment
27957 @deftp {Data Type} zabbix-agent-configuration
27958 Available @code{zabbix-agent-configuration} fields are:
27961 @item @code{zabbix-agent} (default: @code{zabbix-agentd}) (type: file-like)
27962 The zabbix-agent package.
27964 @item @code{user} (default: @code{"zabbix"}) (type: string)
27965 User who will run the Zabbix agent.
27967 @item @code{group} (default: @code{"zabbix"}) (type: group)
27968 Group who will run the Zabbix agent.
27970 @item @code{hostname} (default: @code{""}) (type: string)
27971 Unique, case sensitive hostname which is required for active checks and
27972 must match hostname as configured on the server.
27974 @item @code{log-type} (default: @code{""}) (type: string)
27975 Specifies where log messages are written to:
27979 @code{system} - syslog.
27981 @item @code{file} - file specified with
27982 @code{log-file} parameter.
27984 @item @code{console} - standard output.
27988 @item @code{log-file} (default: @code{"/var/log/zabbix/agent.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_agent.pid"}) (type: string)
27994 @item @code{server} (default: @code{("127.0.0.1")}) (type: list)
27995 List of IP addresses, optionally in CIDR notation, or hostnames of
27996 Zabbix servers and Zabbix proxies. Incoming connections will be
27997 accepted only from the hosts listed here.
27999 @item @code{server-active} (default: @code{("127.0.0.1")}) (type: list)
28000 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
28001 proxies for active checks. If port is not specified, default port is
28002 used. If this parameter is not specified, active checks are disabled.
28004 @item @code{extra-options} (default: @code{""}) (type: extra-options)
28005 Extra options will be appended to Zabbix server configuration file.
28007 @item @code{include-files} (default: @code{()}) (type: include-files)
28008 You may include individual files or all files in a directory in the
28009 configuration file.
28016 @c %end of fragment
28018 @anchor{zabbix-front-end}
28019 @subsubheading Zabbix front-end
28020 @cindex zabbix zabbix-front-end
28022 The Zabbix front-end provides a web interface to Zabbix. It does not need
28023 to run on the same machine as the Zabbix server. This service works by
28024 extending the @ref{PHP-FPM} and @ref{NGINX} services with the configuration
28025 necessary for loading the Zabbix user interface.
28027 @defvar {Scheme variable} zabbix-front-end-service-type
28028 This is the service type for the Zabbix web frontend. Its value must be a
28029 @code{zabbix-front-end-configuration} record, shown below.
28032 @c %start of fragment
28034 @deftp {Data Type} zabbix-front-end-configuration
28035 Available @code{zabbix-front-end-configuration} fields are:
28038 @item @code{zabbix-server} (default: @code{zabbix-server}) (type: file-like)
28039 The Zabbix server package to use.
28041 @item @code{nginx} (default: @code{()}) (type: list)
28042 List of @ref{nginx-server-configuration,@code{nginx-server-configuration}}
28043 blocks for the Zabbix front-end. When empty, a default that listens on
28046 @item @code{db-host} (default: @code{"localhost"}) (type: string)
28047 Database host name.
28049 @item @code{db-port} (default: @code{5432}) (type: number)
28052 @item @code{db-name} (default: @code{"zabbix"}) (type: string)
28055 @item @code{db-user} (default: @code{"zabbix"}) (type: string)
28058 @item @code{db-password} (default: @code{""}) (type: string)
28059 Database password. Please, use @code{db-secret-file} instead.
28061 @item @code{db-secret-file} (default: @code{""}) (type: string)
28062 Secret file which will be appended to @file{zabbix.conf.php} file. This
28063 file contains credentials for use by Zabbix front-end. You are expected
28064 to create it manually.
28066 @item @code{zabbix-host} (default: @code{"localhost"}) (type: string)
28067 Zabbix server hostname.
28069 @item @code{zabbix-port} (default: @code{10051}) (type: number)
28070 Zabbix server port.
28077 @c %end of fragment
28079 @node Kerberos Services
28080 @subsection Kerberos Services
28083 The @code{(gnu services kerberos)} module provides services relating to
28084 the authentication protocol @dfn{Kerberos}.
28086 @subsubheading Krb5 Service
28088 Programs using a Kerberos client library normally
28089 expect a configuration file in @file{/etc/krb5.conf}.
28090 This service generates such a file from a definition provided in the
28091 operating system declaration.
28092 It does not cause any daemon to be started.
28094 No ``keytab'' files are provided by this service---you must explicitly create them.
28095 This service is known to work with the MIT client library, @code{mit-krb5}.
28096 Other implementations have not been tested.
28098 @defvr {Scheme Variable} krb5-service-type
28099 A service type for Kerberos 5 clients.
28103 Here is an example of its use:
28105 (service krb5-service-type
28106 (krb5-configuration
28107 (default-realm "EXAMPLE.COM")
28108 (allow-weak-crypto? #t)
28111 (name "EXAMPLE.COM")
28112 (admin-server "groucho.example.com")
28113 (kdc "karl.example.com"))
28116 (admin-server "kerb-admin.argrx.edu")
28117 (kdc "keys.argrx.edu"))))))
28121 This example provides a Kerberos@tie{}5 client configuration which:
28123 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
28124 of which have distinct administration servers and key distribution centers;
28125 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
28126 specified by clients;
28127 @item Accepts services which only support encryption types known to be weak.
28130 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
28131 Only the most commonly used ones are described here.
28132 For a full list, and more detailed explanation of each, see the MIT
28133 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
28137 @deftp {Data Type} krb5-realm
28138 @cindex realm, kerberos
28141 This field is a string identifying the name of the realm.
28142 A common convention is to use the fully qualified DNS name of your organization,
28143 converted to upper case.
28145 @item @code{admin-server}
28146 This field is a string identifying the host where the administration server is
28150 This field is a string identifying the key distribution center
28155 @deftp {Data Type} krb5-configuration
28158 @item @code{allow-weak-crypto?} (default: @code{#f})
28159 If this flag is @code{#t} then services which only offer encryption algorithms
28160 known to be weak will be accepted.
28162 @item @code{default-realm} (default: @code{#f})
28163 This field should be a string identifying the default Kerberos
28164 realm for the client.
28165 You should set this field to the name of your Kerberos realm.
28166 If this value is @code{#f}
28167 then a realm must be specified with every Kerberos principal when invoking programs
28168 such as @command{kinit}.
28170 @item @code{realms}
28171 This should be a non-empty list of @code{krb5-realm} objects, which clients may
28173 Normally, one of them will have a @code{name} field matching the @code{default-realm}
28179 @subsubheading PAM krb5 Service
28182 The @code{pam-krb5} service allows for login authentication and password
28183 management via Kerberos.
28184 You will need this service if you want PAM enabled applications to authenticate
28185 users using Kerberos.
28187 @defvr {Scheme Variable} pam-krb5-service-type
28188 A service type for the Kerberos 5 PAM module.
28191 @deftp {Data Type} pam-krb5-configuration
28192 Data type representing the configuration of the Kerberos 5 PAM module.
28193 This type has the following parameters:
28195 @item @code{pam-krb5} (default: @code{pam-krb5})
28196 The pam-krb5 package to use.
28198 @item @code{minimum-uid} (default: @code{1000})
28199 The smallest user ID for which Kerberos authentications should be attempted.
28200 Local accounts with lower values will silently fail to authenticate.
28205 @node LDAP Services
28206 @subsection LDAP Services
28208 @cindex nslcd, LDAP service
28210 The @code{(gnu services authentication)} module provides the
28211 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
28212 server. In addition to configuring the service itself, you may want to add
28213 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
28214 Switch} for detailed information.
28216 Here is a simple operating system declaration with a default configuration of
28217 the @code{nslcd-service-type} and a Name Service Switch configuration that
28218 consults the @code{ldap} name service last:
28221 (use-service-modules authentication)
28222 (use-modules (gnu system nss))
28228 (service nslcd-service-type)
28229 (service dhcp-client-service-type)
28231 (name-service-switch
28232 (let ((services (list (name-service (name "db"))
28233 (name-service (name "files"))
28234 (name-service (name "ldap")))))
28235 (name-service-switch
28236 (inherit %mdns-host-lookup-nss)
28237 (password services)
28240 (netgroup services)
28241 (gshadow services)))))
28244 @c %start of generated documentation for nslcd-configuration
28246 Available @code{nslcd-configuration} fields are:
28248 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
28249 The @code{nss-pam-ldapd} package to use.
28253 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
28254 The number of threads to start that can handle requests and perform LDAP
28255 queries. Each thread opens a separate connection to the LDAP server.
28256 The default is to start 5 threads.
28258 Defaults to @samp{disabled}.
28262 @deftypevr {@code{nslcd-configuration} parameter} string uid
28263 This specifies the user id with which the daemon should be run.
28265 Defaults to @samp{"nslcd"}.
28269 @deftypevr {@code{nslcd-configuration} parameter} string gid
28270 This specifies the group id with which the daemon should be run.
28272 Defaults to @samp{"nslcd"}.
28276 @deftypevr {@code{nslcd-configuration} parameter} log-option log
28277 This option controls the way logging is done via a list containing
28278 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
28279 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
28280 argument is optional and specifies the log level. The log level may be
28281 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
28282 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
28283 specified log level or higher are logged.
28285 Defaults to @samp{("/var/log/nslcd" info)}.
28289 @deftypevr {@code{nslcd-configuration} parameter} list uri
28290 The list of LDAP server URIs. Normally, only the first server will be
28291 used with the following servers as fall-back.
28293 Defaults to @samp{("ldap://localhost:389/")}.
28297 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
28298 The version of the LDAP protocol to use. The default is to use the
28299 maximum version supported by the LDAP library.
28301 Defaults to @samp{disabled}.
28305 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
28306 Specifies the distinguished name with which to bind to the directory
28307 server for lookups. The default is to bind anonymously.
28309 Defaults to @samp{disabled}.
28313 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
28314 Specifies the credentials with which to bind. This option is only
28315 applicable when used with binddn.
28317 Defaults to @samp{disabled}.
28321 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
28322 Specifies the distinguished name to use when the root user tries to
28323 modify a user's password using the PAM module.
28325 Defaults to @samp{disabled}.
28329 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
28330 Specifies the credentials with which to bind if the root user tries to
28331 change a user's password. This option is only applicable when used with
28334 Defaults to @samp{disabled}.
28338 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
28339 Specifies the SASL mechanism to be used when performing SASL
28342 Defaults to @samp{disabled}.
28346 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
28347 Specifies the SASL realm to be used when performing SASL authentication.
28349 Defaults to @samp{disabled}.
28353 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
28354 Specifies the authentication identity to be used when performing SASL
28357 Defaults to @samp{disabled}.
28361 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
28362 Specifies the authorization identity to be used when performing SASL
28365 Defaults to @samp{disabled}.
28369 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
28370 Determines whether the LDAP server host name should be canonicalised. If
28371 this is enabled the LDAP library will do a reverse host name lookup. By
28372 default, it is left up to the LDAP library whether this check is
28375 Defaults to @samp{disabled}.
28379 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
28380 Set the name for the GSS-API Kerberos credentials cache.
28382 Defaults to @samp{disabled}.
28386 @deftypevr {@code{nslcd-configuration} parameter} string base
28387 The directory search base.
28389 Defaults to @samp{"dc=example,dc=com"}.
28393 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
28394 Specifies the search scope (subtree, onelevel, base or children). The
28395 default scope is subtree; base scope is almost never useful for name
28396 service lookups; children scope is not supported on all servers.
28398 Defaults to @samp{(subtree)}.
28402 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
28403 Specifies the policy for dereferencing aliases. The default policy is
28404 to never dereference aliases.
28406 Defaults to @samp{disabled}.
28410 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
28411 Specifies whether automatic referral chasing should be enabled. The
28412 default behaviour is to chase referrals.
28414 Defaults to @samp{disabled}.
28418 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
28419 This option allows for custom attributes to be looked up instead of the
28420 default RFC 2307 attributes. It is a list of maps, each consisting of
28421 the name of a map, the RFC 2307 attribute to match and the query
28422 expression for the attribute as it is available in the directory.
28424 Defaults to @samp{()}.
28428 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
28429 A list of filters consisting of the name of a map to which the filter
28430 applies and an LDAP search filter expression.
28432 Defaults to @samp{()}.
28436 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
28437 Specifies the time limit in seconds to use when connecting to the
28438 directory server. The default value is 10 seconds.
28440 Defaults to @samp{disabled}.
28444 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
28445 Specifies the time limit (in seconds) to wait for a response from the
28446 LDAP server. A value of zero, which is the default, is to wait
28447 indefinitely for searches to be completed.
28449 Defaults to @samp{disabled}.
28453 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
28454 Specifies the period if inactivity (in seconds) after which the con‐
28455 nection to the LDAP server will be closed. The default is not to time
28458 Defaults to @samp{disabled}.
28462 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
28463 Specifies the number of seconds to sleep when connecting to all LDAP
28464 servers fails. By default one second is waited between the first
28465 failure and the first retry.
28467 Defaults to @samp{disabled}.
28471 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
28472 Specifies the time after which the LDAP server is considered to be
28473 permanently unavailable. Once this time is reached retries will be done
28474 only once per this time period. The default value is 10 seconds.
28476 Defaults to @samp{disabled}.
28480 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
28481 Specifies whether to use SSL/TLS or not (the default is not to). If
28482 'start-tls is specified then StartTLS is used rather than raw LDAP over
28485 Defaults to @samp{disabled}.
28489 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
28490 Specifies what checks to perform on a server-supplied certificate. The
28491 meaning of the values is described in the ldap.conf(5) manual page.
28493 Defaults to @samp{disabled}.
28497 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
28498 Specifies the directory containing X.509 certificates for peer authen‐
28499 tication. This parameter is ignored when using GnuTLS.
28501 Defaults to @samp{disabled}.
28505 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
28506 Specifies the path to the X.509 certificate for peer authentication.
28508 Defaults to @samp{disabled}.
28512 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
28513 Specifies the path to an entropy source. This parameter is ignored when
28516 Defaults to @samp{disabled}.
28520 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
28521 Specifies the ciphers to use for TLS as a string.
28523 Defaults to @samp{disabled}.
28527 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
28528 Specifies the path to the file containing the local certificate for
28529 client TLS authentication.
28531 Defaults to @samp{disabled}.
28535 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
28536 Specifies the path to the file containing the private key for client TLS
28539 Defaults to @samp{disabled}.
28543 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
28544 Set this to a number greater than 0 to request paged results from the
28545 LDAP server in accordance with RFC2696. The default (0) is to not
28546 request paged results.
28548 Defaults to @samp{disabled}.
28552 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
28553 This option prevents group membership lookups through LDAP for the
28554 specified users. Alternatively, the value 'all-local may be used. With
28555 that value nslcd builds a full list of non-LDAP users on startup.
28557 Defaults to @samp{disabled}.
28561 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
28562 This option ensures that LDAP users with a numeric user id lower than
28563 the specified value are ignored.
28565 Defaults to @samp{disabled}.
28569 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
28570 This option specifies an offset that is added to all LDAP numeric user
28571 ids. This can be used to avoid user id collisions with local users.
28573 Defaults to @samp{disabled}.
28577 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
28578 This option specifies an offset that is added to all LDAP numeric group
28579 ids. This can be used to avoid user id collisions with local groups.
28581 Defaults to @samp{disabled}.
28585 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
28586 If this option is set, the member attribute of a group may point to
28587 another group. Members of nested groups are also returned in the higher
28588 level group and parent groups are returned when finding groups for a
28589 specific user. The default is not to perform extra searches for nested
28592 Defaults to @samp{disabled}.
28596 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
28597 If this option is set, the group member list is not retrieved when
28598 looking up groups. Lookups for finding which groups a user belongs to
28599 will remain functional so the user will likely still get the correct
28600 groups assigned on login.
28602 Defaults to @samp{disabled}.
28606 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
28607 If this option is set, functions which cause all user/group entries to
28608 be loaded from the directory will not succeed in doing so. This can
28609 dramatically reduce LDAP server load in situations where there are a
28610 great number of users and/or groups. This option is not recommended for
28611 most configurations.
28613 Defaults to @samp{disabled}.
28617 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
28618 This option can be used to specify how user and group names are verified
28619 within the system. This pattern is used to check all user and group
28620 names that are requested and returned from LDAP.
28622 Defaults to @samp{disabled}.
28626 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
28627 This specifies whether or not to perform searches using case-insensitive
28628 matching. Enabling this could open up the system to authorization
28629 bypass vulnerabilities and introduce nscd cache poisoning
28630 vulnerabilities which allow denial of service.
28632 Defaults to @samp{disabled}.
28636 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
28637 This option specifies whether password policy controls are requested and
28638 handled from the LDAP server when performing user authentication.
28640 Defaults to @samp{disabled}.
28644 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
28645 By default nslcd performs an LDAP search with the user's credentials
28646 after BIND (authentication) to ensure that the BIND operation was
28647 successful. The default search is a simple check to see if the user's
28648 DN exists. A search filter can be specified that will be used instead.
28649 It should return at least one entry.
28651 Defaults to @samp{disabled}.
28655 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
28656 This option allows flexible fine tuning of the authorisation check that
28657 should be performed. The search filter specified is executed and if any
28658 entries match, access is granted, otherwise access is denied.
28660 Defaults to @samp{disabled}.
28664 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
28665 If this option is set password modification using pam_ldap will be
28666 denied and the specified message will be presented to the user instead.
28667 The message can be used to direct the user to an alternative means of
28668 changing their password.
28670 Defaults to @samp{disabled}.
28674 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
28675 List of pam service names for which LDAP authentication should suffice.
28677 Defaults to @samp{()}.
28681 @c %end of generated documentation for nslcd-configuration
28685 @subsection Web Services
28690 The @code{(gnu services web)} module provides the Apache HTTP Server,
28691 the nginx web server, and also a fastcgi wrapper daemon.
28693 @subsubheading Apache HTTP Server
28695 @deffn {Scheme Variable} httpd-service-type
28696 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
28697 (@dfn{httpd}). The value for this service type is a
28698 @code{httpd-configuration} record.
28700 A simple example configuration is given below.
28703 (service httpd-service-type
28704 (httpd-configuration
28707 (server-name "www.example.com")
28708 (document-root "/srv/http/www.example.com")))))
28711 Other services can also extend the @code{httpd-service-type} to add to
28715 (simple-service 'www.example.com-server httpd-service-type
28719 (list (string-join '("ServerName www.example.com"
28720 "DocumentRoot /srv/http/www.example.com")
28725 The details for the @code{httpd-configuration}, @code{httpd-module},
28726 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
28729 @deffn {Data Type} httpd-configuration
28730 This data type represents the configuration for the httpd service.
28733 @item @code{package} (default: @code{httpd})
28734 The httpd package to use.
28736 @item @code{pid-file} (default: @code{"/var/run/httpd"})
28737 The pid file used by the shepherd-service.
28739 @item @code{config} (default: @code{(httpd-config-file)})
28740 The configuration file to use with the httpd service. The default value
28741 is a @code{httpd-config-file} record, but this can also be a different
28742 G-expression that generates a file, for example a @code{plain-file}. A
28743 file outside of the store can also be specified through a string.
28748 @deffn {Data Type} httpd-module
28749 This data type represents a module for the httpd service.
28753 The name of the module.
28756 The file for the module. This can be relative to the httpd package being
28757 used, the absolute location of a file, or a G-expression for a file
28758 within the store, for example @code{(file-append mod-wsgi
28759 "/modules/mod_wsgi.so")}.
28764 @defvr {Scheme Variable} %default-httpd-modules
28765 A default list of @code{httpd-module} objects.
28768 @deffn {Data Type} httpd-config-file
28769 This data type represents a configuration file for the httpd service.
28772 @item @code{modules} (default: @code{%default-httpd-modules})
28773 The modules to load. Additional modules can be added here, or loaded by
28774 additional configuration.
28776 For example, in order to handle requests for PHP files, you can use Apache’s
28777 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
28780 (service httpd-service-type
28781 (httpd-configuration
28786 (name "proxy_module")
28787 (file "modules/mod_proxy.so"))
28789 (name "proxy_fcgi_module")
28790 (file "modules/mod_proxy_fcgi.so"))
28791 %default-httpd-modules))
28792 (extra-config (list "\
28793 <FilesMatch \\.php$>
28794 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
28795 </FilesMatch>"))))))
28796 (service php-fpm-service-type
28797 (php-fpm-configuration
28798 (socket "/var/run/php-fpm.sock")
28799 (socket-group "httpd")))
28802 @item @code{server-root} (default: @code{httpd})
28803 The @code{ServerRoot} in the configuration file, defaults to the httpd
28804 package. Directives including @code{Include} and @code{LoadModule} are
28805 taken as relative to the server root.
28807 @item @code{server-name} (default: @code{#f})
28808 The @code{ServerName} in the configuration file, used to specify the
28809 request scheme, hostname and port that the server uses to identify
28812 This doesn't need to be set in the server config, and can be specified
28813 in virtual hosts. The default is @code{#f} to not specify a
28816 @item @code{document-root} (default: @code{"/srv/http"})
28817 The @code{DocumentRoot} from which files will be served.
28819 @item @code{listen} (default: @code{'("80")})
28820 The list of values for the @code{Listen} directives in the config
28821 file. The value should be a list of strings, when each string can
28822 specify the port number to listen on, and optionally the IP address and
28825 @item @code{pid-file} (default: @code{"/var/run/httpd"})
28826 The @code{PidFile} to use. This should match the @code{pid-file} set in
28827 the @code{httpd-configuration} so that the Shepherd service is
28828 configured correctly.
28830 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
28831 The @code{ErrorLog} to which the server will log errors.
28833 @item @code{user} (default: @code{"httpd"})
28834 The @code{User} which the server will answer requests as.
28836 @item @code{group} (default: @code{"httpd"})
28837 The @code{Group} which the server will answer requests as.
28839 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
28840 A flat list of strings and G-expressions which will be added to the end
28841 of the configuration file.
28843 Any values which the service is extended with will be appended to this
28849 @deffn {Data Type} httpd-virtualhost
28850 This data type represents a virtualhost configuration block for the httpd service.
28852 These should be added to the extra-config for the httpd-service.
28855 (simple-service 'www.example.com-server httpd-service-type
28859 (list (string-join '("ServerName www.example.com"
28860 "DocumentRoot /srv/http/www.example.com")
28865 @item @code{addresses-and-ports}
28866 The addresses and ports for the @code{VirtualHost} directive.
28868 @item @code{contents}
28869 The contents of the @code{VirtualHost} directive, this should be a list
28870 of strings and G-expressions.
28876 @subsubheading NGINX
28878 @deffn {Scheme Variable} nginx-service-type
28879 Service type for the @uref{https://nginx.org/,NGinx} web server. The
28880 value for this service type is a @code{<nginx-configuration>} record.
28882 A simple example configuration is given below.
28885 (service nginx-service-type
28886 (nginx-configuration
28888 (list (nginx-server-configuration
28889 (server-name '("www.example.com"))
28890 (root "/srv/http/www.example.com"))))))
28893 In addition to adding server blocks to the service configuration
28894 directly, this service can be extended by other services to add server
28895 blocks, as in this example:
28898 (simple-service 'my-extra-server nginx-service-type
28899 (list (nginx-server-configuration
28900 (root "/srv/http/extra-website")
28901 (try-files (list "$uri" "$uri/index.html")))))
28905 At startup, @command{nginx} has not yet read its configuration file, so
28906 it uses a default file to log error messages. If it fails to load its
28907 configuration file, that is where error messages are logged. After the
28908 configuration file is loaded, the default error log file changes as per
28909 configuration. In our case, startup error messages can be found in
28910 @file{/var/run/nginx/logs/error.log}, and after configuration in
28911 @file{/var/log/nginx/error.log}. The second location can be changed
28912 with the @var{log-directory} configuration option.
28914 @deffn {Data Type} nginx-configuration
28915 This data type represents the configuration for NGinx. Some
28916 configuration can be done through this and the other provided record
28917 types, or alternatively, a config file can be provided.
28920 @item @code{nginx} (default: @code{nginx})
28921 The nginx package to use.
28923 @item @code{shepherd-requirement} (default: @code{'()})
28924 This is a list of symbols naming Shepherd services the nginx service
28927 This is useful if you would like @command{nginx} to be started after a
28928 back-end web server or a logging service such as Anonip has been
28931 @item @code{log-directory} (default: @code{"/var/log/nginx"})
28932 The directory to which NGinx will write log files.
28934 @item @code{run-directory} (default: @code{"/var/run/nginx"})
28935 The directory in which NGinx will create a pid file, and write temporary
28938 @item @code{server-blocks} (default: @code{'()})
28939 A list of @dfn{server blocks} to create in the generated configuration
28940 file, the elements should be of type
28941 @code{<nginx-server-configuration>}.
28943 The following example would setup NGinx to serve @code{www.example.com}
28944 from the @code{/srv/http/www.example.com} directory, without using
28947 (service nginx-service-type
28948 (nginx-configuration
28950 (list (nginx-server-configuration
28951 (server-name '("www.example.com"))
28952 (root "/srv/http/www.example.com"))))))
28955 @item @code{upstream-blocks} (default: @code{'()})
28956 A list of @dfn{upstream blocks} to create in the generated configuration
28957 file, the elements should be of type
28958 @code{<nginx-upstream-configuration>}.
28960 Configuring upstreams through the @code{upstream-blocks} can be useful
28961 when combined with @code{locations} in the
28962 @code{<nginx-server-configuration>} records. The following example
28963 creates a server configuration with one location configuration, that
28964 will proxy requests to a upstream configuration, which will handle
28965 requests with two servers.
28970 (nginx-configuration
28972 (list (nginx-server-configuration
28973 (server-name '("www.example.com"))
28974 (root "/srv/http/www.example.com")
28977 (nginx-location-configuration
28979 (body '("proxy_pass http://server-proxy;"))))))))
28981 (list (nginx-upstream-configuration
28982 (name "server-proxy")
28983 (servers (list "server1.example.com"
28984 "server2.example.com")))))))
28987 @item @code{file} (default: @code{#f})
28988 If a configuration @var{file} is provided, this will be used, rather than
28989 generating a configuration file from the provided @code{log-directory},
28990 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
28991 proper operation, these arguments should match what is in @var{file} to ensure
28992 that the directories are created when the service is activated.
28994 This can be useful if you have an existing configuration file, or it's
28995 not possible to do what is required through the other parts of the
28996 nginx-configuration record.
28998 @item @code{server-names-hash-bucket-size} (default: @code{#f})
28999 Bucket size for the server names hash tables, defaults to @code{#f} to
29000 use the size of the processors cache line.
29002 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
29003 Maximum bucket size for the server names hash tables.
29005 @item @code{modules} (default: @code{'()})
29006 List of nginx dynamic modules to load. This should be a list of file
29007 names of loadable modules, as in this example:
29012 (file-append nginx-accept-language-module "\
29013 /etc/nginx/modules/ngx_http_accept_language_module.so")
29014 (file-append nginx-lua-module "\
29015 /etc/nginx/modules/ngx_http_lua_module.so")))
29018 @item @code{lua-package-path} (default: @code{'()})
29019 List of nginx lua packages to load. This should be a list of package
29020 names of loadable lua modules, as in this example:
29023 (lua-package-path (list lua-resty-core
29030 @item @code{lua-package-cpath} (default: @code{'()})
29031 List of nginx lua C packages to load. This should be a list of package
29032 names of loadable lua C modules, as in this example:
29035 (lua-package-cpath (list lua-resty-signal))
29038 @item @code{global-directives} (default: @code{'((events . ()))})
29039 Association list of global directives for the top level of the nginx
29040 configuration. Values may themselves be association lists.
29044 `((worker_processes . 16)
29046 (events . ((worker_connections . 1024)))))
29049 @item @code{extra-content} (default: @code{""})
29050 Extra content for the @code{http} block. Should be string or a string
29051 valued G-expression.
29056 @anchor{nginx-server-configuration}
29057 @deftp {Data Type} nginx-server-configuration
29058 Data type representing the configuration of an nginx server block.
29059 This type has the following parameters:
29062 @item @code{listen} (default: @code{'("80" "443 ssl")})
29063 Each @code{listen} directive sets the address and port for IP, or the
29064 path for a UNIX-domain socket on which the server will accept requests.
29065 Both address and port, or only address or only port can be specified.
29066 An address may also be a hostname, for example:
29069 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
29072 @item @code{server-name} (default: @code{(list 'default)})
29073 A list of server names this server represents. @code{'default} represents the
29074 default server for connections matching no other server.
29076 @item @code{root} (default: @code{"/srv/http"})
29077 Root of the website nginx will serve.
29079 @item @code{locations} (default: @code{'()})
29080 A list of @dfn{nginx-location-configuration} or
29081 @dfn{nginx-named-location-configuration} records to use within this
29084 @item @code{index} (default: @code{(list "index.html")})
29085 Index files to look for when clients ask for a directory. If it cannot be found,
29086 Nginx will send the list of files in the directory.
29088 @item @code{try-files} (default: @code{'()})
29089 A list of files whose existence is checked in the specified order.
29090 @code{nginx} will use the first file it finds to process the request.
29092 @item @code{ssl-certificate} (default: @code{#f})
29093 Where to find the certificate for secure connections. Set it to @code{#f} if
29094 you don't have a certificate or you don't want to use HTTPS.
29096 @item @code{ssl-certificate-key} (default: @code{#f})
29097 Where to find the private key for secure connections. Set it to @code{#f} if
29098 you don't have a key or you don't want to use HTTPS.
29100 @item @code{server-tokens?} (default: @code{#f})
29101 Whether the server should add its configuration to response.
29103 @item @code{raw-content} (default: @code{'()})
29104 A list of raw lines added to the server block.
29109 @deftp {Data Type} nginx-upstream-configuration
29110 Data type representing the configuration of an nginx @code{upstream}
29111 block. This type has the following parameters:
29115 Name for this group of servers.
29117 @item @code{servers}
29118 Specify the addresses of the servers in the group. The address can be
29119 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
29120 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
29121 prefix @samp{unix:}. For addresses using an IP address or domain name,
29122 the default port is 80, and a different port can be specified
29125 @item @code{extra-content}
29126 A string or list of strings to add to the upstream block.
29131 @deftp {Data Type} nginx-location-configuration
29132 Data type representing the configuration of an nginx @code{location}
29133 block. This type has the following parameters:
29137 URI which this location block matches.
29139 @anchor{nginx-location-configuration body}
29141 Body of the location block, specified as a list of strings. This can contain
29143 configuration directives. For example, to pass requests to a upstream
29144 server group defined using an @code{nginx-upstream-configuration} block,
29145 the following directive would be specified in the body @samp{(list "proxy_pass
29146 http://upstream-name;")}.
29151 @deftp {Data Type} nginx-named-location-configuration
29152 Data type representing the configuration of an nginx named location
29153 block. Named location blocks are used for request redirection, and not
29154 used for regular request processing. This type has the following
29159 Name to identify this location block.
29162 @xref{nginx-location-configuration body}, as the body for named location
29163 blocks can be used in a similar way to the
29164 @code{nginx-location-configuration body}. One restriction is that the
29165 body of a named location block cannot contain location blocks.
29170 @subsubheading Varnish Cache
29172 Varnish is a fast cache server that sits in between web applications
29173 and end users. It proxies requests from clients and caches the
29174 accessed URLs such that multiple requests for the same resource only
29175 creates one request to the back-end.
29177 @defvr {Scheme Variable} varnish-service-type
29178 Service type for the Varnish daemon.
29181 @deftp {Data Type} varnish-configuration
29182 Data type representing the @code{varnish} service configuration.
29183 This type has the following parameters:
29186 @item @code{package} (default: @code{varnish})
29187 The Varnish package to use.
29189 @item @code{name} (default: @code{"default"})
29190 A name for this Varnish instance. Varnish will create a directory in
29191 @file{/var/varnish/} with this name and keep temporary files there. If
29192 the name starts with a forward slash, it is interpreted as an absolute
29195 Pass the @code{-n} argument to other Varnish programs to connect to the
29196 named instance, e.g.@: @command{varnishncsa -n default}.
29198 @item @code{backend} (default: @code{"localhost:8080"})
29199 The backend to use. This option has no effect if @code{vcl} is set.
29201 @item @code{vcl} (default: #f)
29202 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
29203 is @code{#f}, Varnish will proxy @code{backend} using the default
29204 configuration. Otherwise this must be a file-like object with valid
29207 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
29208 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
29209 can do something along these lines:
29212 (define %gnu-mirror
29213 (plain-file "gnu.vcl"
29215 backend gnu @{ .host = \"www.gnu.org\"; @}"))
29219 (services (cons (service varnish-service-type
29220 (varnish-configuration
29222 (vcl %gnu-mirror)))
29226 The configuration of an already running Varnish instance can be inspected
29227 and changed using the @command{varnishadm} program.
29229 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
29230 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
29231 comprehensive documentation on Varnish and its configuration language.
29233 @item @code{listen} (default: @code{'("localhost:80")})
29234 List of addresses Varnish will listen on.
29236 @item @code{storage} (default: @code{'("malloc,128m")})
29237 List of storage backends that will be available in VCL.
29239 @item @code{parameters} (default: @code{'()})
29240 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
29242 @item @code{extra-options} (default: @code{'()})
29243 Additional arguments to pass to the @command{varnishd} process.
29248 @subsubheading Patchwork
29250 Patchwork is a patch tracking system. It can collect patches sent to a
29251 mailing list, and display them in a web interface.
29253 @defvr {Scheme Variable} patchwork-service-type
29254 Service type for Patchwork.
29257 The following example is an example of a minimal service for Patchwork, for
29258 the @code{patchwork.example.com} domain.
29261 (service patchwork-service-type
29262 (patchwork-configuration
29263 (domain "patchwork.example.com")
29265 (patchwork-settings-module
29266 (allowed-hosts (list domain))
29267 (default-from-email "patchwork@@patchwork.example.com")))
29268 (getmail-retriever-config
29269 (getmail-retriever-configuration
29270 (type "SimpleIMAPSSLRetriever")
29271 (server "imap.example.com")
29273 (username "patchwork")
29275 (list (file-append coreutils "/bin/cat")
29276 "/etc/getmail-patchwork-imap-password"))
29278 '((mailboxes . ("Patches"))))))))
29282 There are three records for configuring the Patchwork service. The
29283 @code{<patchwork-configuration>} relates to the configuration for Patchwork
29284 within the HTTPD service.
29286 The @code{settings-module} field within the @code{<patchwork-configuration>}
29287 record can be populated with the @code{<patchwork-settings-module>} record,
29288 which describes a settings module that is generated within the Guix store.
29290 For the @code{database-configuration} field within the
29291 @code{<patchwork-settings-module>}, the
29292 @code{<patchwork-database-configuration>} must be used.
29294 @deftp {Data Type} patchwork-configuration
29295 Data type representing the Patchwork service configuration. This type has the
29296 following parameters:
29299 @item @code{patchwork} (default: @code{patchwork})
29300 The Patchwork package to use.
29302 @item @code{domain}
29303 The domain to use for Patchwork, this is used in the HTTPD service virtual
29306 @item @code{settings-module}
29307 The settings module to use for Patchwork. As a Django application, Patchwork
29308 is configured with a Python module containing the settings. This can either be
29309 an instance of the @code{<patchwork-settings-module>} record, any other record
29310 that represents the settings in the store, or a directory outside of the
29313 @item @code{static-path} (default: @code{"/static/"})
29314 The path under which the HTTPD service should serve the static files.
29316 @item @code{getmail-retriever-config}
29317 The getmail-retriever-configuration record value to use with
29318 Patchwork. Getmail will be configured with this value, the messages will be
29319 delivered to Patchwork.
29324 @deftp {Data Type} patchwork-settings-module
29325 Data type representing a settings module for Patchwork. Some of these
29326 settings relate directly to Patchwork, but others relate to Django, the web
29327 framework used by Patchwork, or the Django Rest Framework library. This type
29328 has the following parameters:
29331 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
29332 The database connection settings used for Patchwork. See the
29333 @code{<patchwork-database-configuration>} record type for more information.
29335 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
29336 Patchwork, as a Django web application uses a secret key for cryptographically
29337 signing values. This file should contain a unique unpredictable value.
29339 If this file does not exist, it will be created and populated with a random
29340 value by the patchwork-setup shepherd service.
29342 This setting relates to Django.
29344 @item @code{allowed-hosts}
29345 A list of valid hosts for this Patchwork service. This should at least include
29346 the domain specified in the @code{<patchwork-configuration>} record.
29348 This is a Django setting.
29350 @item @code{default-from-email}
29351 The email address from which Patchwork should send email by default.
29353 This is a Patchwork setting.
29355 @item @code{static-url} (default: @code{#f})
29356 The URL to use when serving static assets. It can be part of a URL, or a full
29357 URL, but must end in a @code{/}.
29359 If the default value is used, the @code{static-path} value from the
29360 @code{<patchwork-configuration>} record will be used.
29362 This is a Django setting.
29364 @item @code{admins} (default: @code{'()})
29365 Email addresses to send the details of errors that occur. Each value should
29366 be a list containing two elements, the name and then the email address.
29368 This is a Django setting.
29370 @item @code{debug?} (default: @code{#f})
29371 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
29372 messages will be shown.
29374 This is a Django setting.
29376 @item @code{enable-rest-api?} (default: @code{#t})
29377 Whether to enable the Patchwork REST API.
29379 This is a Patchwork setting.
29381 @item @code{enable-xmlrpc?} (default: @code{#t})
29382 Whether to enable the XML RPC API.
29384 This is a Patchwork setting.
29386 @item @code{force-https-links?} (default: @code{#t})
29387 Whether to use HTTPS links on Patchwork pages.
29389 This is a Patchwork setting.
29391 @item @code{extra-settings} (default: @code{""})
29392 Extra code to place at the end of the Patchwork settings module.
29397 @deftp {Data Type} patchwork-database-configuration
29398 Data type representing the database configuration for Patchwork.
29401 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
29402 The database engine to use.
29404 @item @code{name} (default: @code{"patchwork"})
29405 The name of the database to use.
29407 @item @code{user} (default: @code{"httpd"})
29408 The user to connect to the database as.
29410 @item @code{password} (default: @code{""})
29411 The password to use when connecting to the database.
29413 @item @code{host} (default: @code{""})
29414 The host to make the database connection to.
29416 @item @code{port} (default: @code{""})
29417 The port on which to connect to the database.
29422 @subsubheading Mumi
29424 @cindex Mumi, Debbugs Web interface
29425 @cindex Debbugs, Mumi Web interface
29426 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
29427 Web interface to the Debbugs bug tracker, by default for
29428 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
29429 but it also fetches and indexes mail retrieved from Debbugs.
29431 @defvr {Scheme Variable} mumi-service-type
29432 This is the service type for Mumi.
29435 @deftp {Data Type} mumi-configuration
29436 Data type representing the Mumi service configuration. This type has the
29440 @item @code{mumi} (default: @code{mumi})
29441 The Mumi package to use.
29443 @item @code{mailer?} (default: @code{#true})
29444 Whether to enable or disable the mailer component.
29446 @item @code{mumi-configuration-sender}
29447 The email address used as the sender for comments.
29449 @item @code{mumi-configuration-smtp}
29450 A URI to configure the SMTP settings for Mailutils. This could be
29451 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
29452 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
29453 mailutils, GNU@tie{}Mailutils}.
29459 @subsubheading FastCGI
29462 FastCGI is an interface between the front-end and the back-end of a web
29463 service. It is a somewhat legacy facility; new web services should
29464 generally just talk HTTP between the front-end and the back-end.
29465 However there are a number of back-end services such as PHP or the
29466 optimized HTTP Git repository access that use FastCGI, so we have
29467 support for it in Guix.
29469 To use FastCGI, you configure the front-end web server (e.g., nginx) to
29470 dispatch some subset of its requests to the fastcgi backend, which
29471 listens on a local TCP or UNIX socket. There is an intermediary
29472 @code{fcgiwrap} program that sits between the actual backend process and
29473 the web server. The front-end indicates which backend program to run,
29474 passing that information to the @code{fcgiwrap} process.
29476 @defvr {Scheme Variable} fcgiwrap-service-type
29477 A service type for the @code{fcgiwrap} FastCGI proxy.
29480 @deftp {Data Type} fcgiwrap-configuration
29481 Data type representing the configuration of the @code{fcgiwrap} service.
29482 This type has the following parameters:
29484 @item @code{package} (default: @code{fcgiwrap})
29485 The fcgiwrap package to use.
29487 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
29488 The socket on which the @code{fcgiwrap} process should listen, as a
29489 string. Valid @var{socket} values include
29490 @code{unix:@var{/path/to/unix/socket}},
29491 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
29492 @code{tcp6:[@var{ipv6_addr}]:port}.
29494 @item @code{user} (default: @code{fcgiwrap})
29495 @itemx @code{group} (default: @code{fcgiwrap})
29496 The user and group names, as strings, under which to run the
29497 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
29498 the user asks for the specific user or group names @code{fcgiwrap} that
29499 the corresponding user and/or group is present on the system.
29501 It is possible to configure a FastCGI-backed web service to pass HTTP
29502 authentication information from the front-end to the back-end, and to
29503 allow @code{fcgiwrap} to run the back-end process as a corresponding
29504 local user. To enable this capability on the back-end, run
29505 @code{fcgiwrap} as the @code{root} user and group. Note that this
29506 capability also has to be configured on the front-end as well.
29511 @subsubheading PHP-FPM
29513 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
29514 with some additional features useful for sites of any size.
29516 These features include:
29518 @item Adaptive process spawning
29519 @item Basic statistics (similar to Apache's mod_status)
29520 @item Advanced process management with graceful stop/start
29521 @item Ability to start workers with different uid/gid/chroot/environment
29522 and different php.ini (replaces safe_mode)
29523 @item Stdout & stderr logging
29524 @item Emergency restart in case of accidental opcode cache destruction
29525 @item Accelerated upload support
29526 @item Support for a "slowlog"
29527 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
29528 a special function to finish request & flush all data while continuing to do
29529 something time-consuming (video converting, stats processing, etc.)
29531 ...@: and much more.
29533 @defvr {Scheme Variable} php-fpm-service-type
29534 A Service type for @code{php-fpm}.
29537 @deftp {Data Type} php-fpm-configuration
29538 Data Type for php-fpm service configuration.
29540 @item @code{php} (default: @code{php})
29541 The php package to use.
29542 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
29543 The address on which to accept FastCGI requests. Valid syntaxes are:
29545 @item @code{"ip.add.re.ss:port"}
29546 Listen on a TCP socket to a specific address on a specific port.
29547 @item @code{"port"}
29548 Listen on a TCP socket to all addresses on a specific port.
29549 @item @code{"/path/to/unix/socket"}
29550 Listen on a unix socket.
29553 @item @code{user} (default: @code{php-fpm})
29554 User who will own the php worker processes.
29555 @item @code{group} (default: @code{php-fpm})
29556 Group of the worker processes.
29557 @item @code{socket-user} (default: @code{php-fpm})
29558 User who can speak to the php-fpm socket.
29559 @item @code{socket-group} (default: @code{nginx})
29560 Group that can speak to the php-fpm socket.
29561 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
29562 The process id of the php-fpm process is written to this file
29563 once the service has started.
29564 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
29565 Log for the php-fpm master process.
29566 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
29567 Detailed settings for the php-fpm process manager.
29570 @item @code{<php-fpm-dynamic-process-manager-configuration>}
29571 @item @code{<php-fpm-static-process-manager-configuration>}
29572 @item @code{<php-fpm-on-demand-process-manager-configuration>}
29574 @item @code{display-errors} (default @code{#f})
29575 Determines whether php errors and warning should be sent to clients
29576 and displayed in their browsers.
29577 This is useful for local php development, but a security risk for public sites,
29578 as error messages can reveal passwords and personal data.
29579 @item @code{timezone} (default @code{#f})
29580 Specifies @code{php_admin_value[date.timezone]} parameter.
29581 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
29582 This file will log the @code{stderr} outputs of php worker processes.
29583 Can be set to @code{#f} to disable logging.
29584 @item @code{file} (default @code{#f})
29585 An optional override of the whole configuration.
29586 You can use the @code{mixed-text-file} function or an absolute filepath for it.
29587 @item @code{php-ini-file} (default @code{#f})
29588 An optional override of the default php settings.
29589 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
29590 You can use the @code{mixed-text-file} function or an absolute filepath for it.
29592 For local development it is useful to set a higher timeout and memory
29593 limit for spawned php processes. This be accomplished with the
29594 following operating system configuration snippet:
29596 (define %local-php-ini
29597 (plain-file "php.ini"
29599 max_execution_time = 1800"))
29603 (services (cons (service php-fpm-service-type
29604 (php-fpm-configuration
29605 (php-ini-file %local-php-ini)))
29609 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
29610 directives} for comprehensive documentation on the acceptable
29611 @file{php.ini} directives.
29615 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
29616 Data Type for the @code{dynamic} php-fpm process manager. With the
29617 @code{dynamic} process manager, spare worker processes are kept around
29618 based on its configured limits.
29620 @item @code{max-children} (default: @code{5})
29621 Maximum of worker processes.
29622 @item @code{start-servers} (default: @code{2})
29623 How many worker processes should be started on start-up.
29624 @item @code{min-spare-servers} (default: @code{1})
29625 How many spare worker processes should be kept around at minimum.
29626 @item @code{max-spare-servers} (default: @code{3})
29627 How many spare worker processes should be kept around at maximum.
29631 @deftp {Data type} php-fpm-static-process-manager-configuration
29632 Data Type for the @code{static} php-fpm process manager. With the
29633 @code{static} process manager, an unchanging number of worker processes
29636 @item @code{max-children} (default: @code{5})
29637 Maximum of worker processes.
29641 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
29642 Data Type for the @code{on-demand} php-fpm process manager. With the
29643 @code{on-demand} process manager, worker processes are only created as
29646 @item @code{max-children} (default: @code{5})
29647 Maximum of worker processes.
29648 @item @code{process-idle-timeout} (default: @code{10})
29649 The time in seconds after which a process with no requests is killed.
29654 @deffn {Scheme Procedure} nginx-php-location @
29655 [#:nginx-package nginx] @
29656 [socket (string-append "/var/run/php" @
29657 (version-major (package-version php)) @
29659 A helper function to quickly add php to an @code{nginx-server-configuration}.
29662 A simple services setup for nginx with php can look like this:
29664 (services (cons* (service dhcp-client-service-type)
29665 (service php-fpm-service-type)
29666 (service nginx-service-type
29667 (nginx-server-configuration
29668 (server-name '("example.com"))
29669 (root "/srv/http/")
29671 (list (nginx-php-location)))
29673 (ssl-certificate #f)
29674 (ssl-certificate-key #f)))
29678 @cindex cat-avatar-generator
29679 The cat avatar generator is a simple service to demonstrate the use of php-fpm
29680 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
29681 the hash of a user's email address.
29683 @deffn {Scheme Procedure} cat-avatar-generator-service @
29684 [#:cache-dir "/var/cache/cat-avatar-generator"] @
29685 [#:package cat-avatar-generator] @
29686 [#:configuration (nginx-server-configuration)]
29687 Returns an nginx-server-configuration that inherits @code{configuration}. It
29688 extends the nginx configuration to add a server block that serves @code{package},
29689 a version of cat-avatar-generator. During execution, cat-avatar-generator will
29690 be able to use @code{cache-dir} as its cache directory.
29693 A simple setup for cat-avatar-generator can look like this:
29695 (services (cons* (cat-avatar-generator-service
29697 (nginx-server-configuration
29698 (server-name '("example.com"))))
29703 @subsubheading Hpcguix-web
29705 @cindex hpcguix-web
29706 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
29707 program is a customizable web interface to browse Guix packages,
29708 initially designed for users of high-performance computing (HPC)
29711 @defvr {Scheme Variable} hpcguix-web-service-type
29712 The service type for @code{hpcguix-web}.
29715 @deftp {Data Type} hpcguix-web-configuration
29716 Data type for the hpcguix-web service configuration.
29720 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
29721 configuration. The main items available in this spec are:
29724 @item @code{title-prefix} (default: @code{"hpcguix | "})
29725 The page title prefix.
29727 @item @code{guix-command} (default: @code{"guix"})
29728 The @command{guix} command.
29730 @item @code{package-filter-proc} (default: @code{(const #t)})
29731 A procedure specifying how to filter packages that are displayed.
29733 @item @code{package-page-extension-proc} (default: @code{(const '())})
29734 Extension package for @code{hpcguix-web}.
29736 @item @code{menu} (default: @code{'()})
29737 Additional entry in page @code{menu}.
29739 @item @code{channels} (default: @code{%default-channels})
29740 List of channels from which the package list is built (@pxref{Channels}).
29742 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
29743 The expiration time, in seconds, after which the package list is rebuilt from
29744 the latest instances of the given channels.
29747 See the hpcguix-web repository for a
29748 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
29751 @item @code{package} (default: @code{hpcguix-web})
29752 The hpcguix-web package to use.
29754 @item @code{address} (default: @code{"127.0.0.1"})
29755 The IP address to listen to.
29757 @item @code{port} (default: @code{5000})
29758 The port number to listen to.
29762 A typical hpcguix-web service declaration looks like this:
29765 (service hpcguix-web-service-type
29766 (hpcguix-web-configuration
29768 #~(define site-config
29769 (hpcweb-configuration
29770 (title-prefix "Guix-HPC - ")
29771 (menu '(("/about" "ABOUT"))))))))
29775 The hpcguix-web service periodically updates the package list it publishes by
29776 pulling channels from Git. To that end, it needs to access X.509 certificates
29777 so that it can authenticate Git servers when communicating over HTTPS, and it
29778 assumes that @file{/etc/ssl/certs} contains those certificates.
29780 Thus, make sure to add @code{nss-certs} or another certificate package to the
29781 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
29782 more information on X.509 certificates.
29785 @subsubheading gmnisrv
29788 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
29789 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
29791 @deffn {Scheme Variable} gmnisrv-service-type
29792 This is the type of the gmnisrv service, whose value should be a
29793 @code{gmnisrv-configuration} object, as in this example:
29796 (service gmnisrv-service-type
29797 (gmnisrv-configuration
29798 (config-file (local-file "./my-gmnisrv.ini"))))
29802 @deftp {Data Type} gmnisrv-configuration
29803 Data type representing the configuration of gmnisrv.
29806 @item @code{package} (default: @var{gmnisrv})
29807 Package object of the gmnisrv server.
29809 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
29810 File-like object of the gmnisrv configuration file to use. The default
29811 configuration listens on port 1965 and serves files from
29812 @file{/srv/gemini}. Certificates are stored in
29813 @file{/var/lib/gemini/certs}. For more information, run @command{man
29814 gmnisrv} and @command{man gmnisrv.ini}.
29819 @subsubheading Agate
29822 The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
29823 (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
29824 program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
29825 protocol server written in Rust.
29827 @deffn {Scheme Variable} agate-service-type
29828 This is the type of the agate service, whose value should be an
29829 @code{agate-service-type} object, as in this example:
29832 (service agate-service-type
29833 (agate-configuration
29834 (content "/srv/gemini")
29835 (cert "/srv/cert.pem")
29836 (key "/srv/key.rsa")))
29839 The example above represents the minimal tweaking necessary to get Agate
29840 up and running. Specifying the path to the certificate and key is
29841 always necessary, as the Gemini protocol requires TLS by default.
29843 To obtain a certificate and a key, you could, for example, use OpenSSL,
29844 running a command similar to the following example:
29847 openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
29848 -days 3650 -nodes -subj "/CN=example.com"
29851 Of course, you'll have to replace @i{example.com} with your own domain
29852 name, and then point the Agate configuration towards the path of the
29853 generated key and certificate.
29857 @deftp {Data Type} agate-configuration
29858 Data type representing the configuration of Agate.
29861 @item @code{package} (default: @code{agate})
29862 The package object of the Agate server.
29864 @item @code{content} (default: @file{"/srv/gemini"})
29865 The directory from which Agate will serve files.
29867 @item @code{cert} (default: @code{#f})
29868 The path to the TLS certificate PEM file to be used for encrypted
29869 connections. Must be filled in with a value from the user.
29871 @item @code{key} (default: @code{#f})
29872 The path to the PKCS8 private key file to be used for encrypted
29873 connections. Must be filled in with a value from the user.
29875 @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
29876 A list of the addresses to listen on.
29878 @item @code{hostname} (default: @code{#f})
29879 The domain name of this Gemini server. Optional.
29881 @item @code{lang} (default: @code{#f})
29882 RFC 4646 language code(s) for text/gemini documents. Optional.
29884 @item @code{silent?} (default: @code{#f})
29885 Set to @code{#t} to disable logging output.
29887 @item @code{serve-secret?} (default: @code{#f})
29888 Set to @code{#t} to serve secret files (files/directories starting with
29891 @item @code{log-ip?} (default: @code{#t})
29892 Whether or not to output IP addresses when logging.
29894 @item @code{user} (default: @code{"agate"})
29895 Owner of the @code{agate} process.
29897 @item @code{group} (default: @code{"agate"})
29898 Owner's group of the @code{agate} process.
29900 @item @code{log-file} (default: @file{"/var/log/agate.log"})
29901 The file which should store the logging output of Agate.
29906 @node Certificate Services
29907 @subsection Certificate Services
29910 @cindex HTTP, HTTPS
29911 @cindex Let's Encrypt
29912 @cindex TLS certificates
29913 The @code{(gnu services certbot)} module provides a service to
29914 automatically obtain a valid TLS certificate from the Let's Encrypt
29915 certificate authority. These certificates can then be used to serve
29916 content securely over HTTPS or other TLS-based protocols, with the
29917 knowledge that the client will be able to verify the server's
29920 @url{https://letsencrypt.org/, Let's Encrypt} provides the
29921 @code{certbot} tool to automate the certification process. This tool
29922 first securely generates a key on the server. It then makes a request
29923 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
29924 checks that the request originates from the host in question by using a
29925 challenge-response protocol, requiring the server to provide its
29926 response over HTTP@. If that protocol completes successfully, the CA
29927 signs the key, resulting in a certificate. That certificate is valid
29928 for a limited period of time, and therefore to continue to provide TLS
29929 services, the server needs to periodically ask the CA to renew its
29932 The certbot service automates this process: the initial key
29933 generation, the initial certification request to the Let's Encrypt
29934 service, the web server challenge/response integration, writing the
29935 certificate to disk, the automated periodic renewals, and the deployment
29936 tasks associated with the renewal (e.g.@: reloading services, copying keys
29937 with different permissions).
29939 Certbot is run twice a day, at a random minute within the hour. It
29940 won't do anything until your certificates are due for renewal or
29941 revoked, but running it regularly would give your service a chance of
29942 staying online in case a Let's Encrypt-initiated revocation happened for
29945 By using this service, you agree to the ACME Subscriber Agreement, which
29946 can be found there:
29947 @url{https://acme-v01.api.letsencrypt.org/directory}.
29949 @defvr {Scheme Variable} certbot-service-type
29950 A service type for the @code{certbot} Let's Encrypt client. Its value
29951 must be a @code{certbot-configuration} record as in this example:
29954 (define %nginx-deploy-hook
29956 "nginx-deploy-hook"
29957 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
29958 (kill pid SIGHUP))))
29960 (service certbot-service-type
29961 (certbot-configuration
29962 (email "foo@@example.net")
29965 (certificate-configuration
29966 (domains '("example.net" "www.example.net"))
29967 (deploy-hook %nginx-deploy-hook))
29968 (certificate-configuration
29969 (domains '("bar.example.net")))))))
29972 See below for details about @code{certbot-configuration}.
29975 @deftp {Data Type} certbot-configuration
29976 Data type representing the configuration of the @code{certbot} service.
29977 This type has the following parameters:
29980 @item @code{package} (default: @code{certbot})
29981 The certbot package to use.
29983 @item @code{webroot} (default: @code{/var/www})
29984 The directory from which to serve the Let's Encrypt challenge/response
29987 @item @code{certificates} (default: @code{()})
29988 A list of @code{certificates-configuration}s for which to generate
29989 certificates and request signatures. Each certificate has a @code{name}
29990 and several @code{domains}.
29992 @item @code{email} (default: @code{#f})
29993 Optional email address used for registration and recovery contact.
29994 Setting this is encouraged as it allows you to receive important
29995 notifications about the account and issued certificates.
29997 @item @code{server} (default: @code{#f})
29998 Optional URL of ACME server. Setting this overrides certbot's default,
29999 which is the Let's Encrypt server.
30001 @item @code{rsa-key-size} (default: @code{2048})
30002 Size of the RSA key.
30004 @item @code{default-location} (default: @i{see below})
30005 The default @code{nginx-location-configuration}. Because @code{certbot}
30006 needs to be able to serve challenges and responses, it needs to be able
30007 to run a web server. It does so by extending the @code{nginx} web
30008 service with an @code{nginx-server-configuration} listening on the
30009 @var{domains} on port 80, and which has a
30010 @code{nginx-location-configuration} for the @code{/.well-known/} URI
30011 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
30012 these nginx configuration data types.
30014 Requests to other URL paths will be matched by the
30015 @code{default-location}, which if present is added to all
30016 @code{nginx-server-configuration}s.
30018 By default, the @code{default-location} will issue a redirect from
30019 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
30020 you to define what to serve on your site via @code{https}.
30022 Pass @code{#f} to not issue a default location.
30026 @deftp {Data Type} certificate-configuration
30027 Data type representing the configuration of a certificate.
30028 This type has the following parameters:
30031 @item @code{name} (default: @i{see below})
30032 This name is used by Certbot for housekeeping and in file paths; it
30033 doesn't affect the content of the certificate itself. To see
30034 certificate names, run @code{certbot certificates}.
30036 Its default is the first provided domain.
30038 @item @code{domains} (default: @code{()})
30039 The first domain provided will be the subject CN of the certificate, and
30040 all domains will be Subject Alternative Names on the certificate.
30042 @item @code{challenge} (default: @code{#f})
30043 The challenge type that has to be run by certbot. If @code{#f} is specified,
30044 default to the HTTP challenge. If a value is specified, defaults to the
30045 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
30046 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
30047 and gives Let's Encrypt permission to log the public IP address of the
30048 requesting machine.
30050 @item @code{csr} (default: @code{#f})
30051 File name of Certificate Signing Request (CSR) in DER or PEM format.
30052 If @code{#f} is specified, this argument will not be passed to certbot.
30053 If a value is specified, certbot will use it to obtain a certificate, instead of
30054 using a self-generated CSR.
30055 The domain-name(s) mentioned in @code{domains}, must be consistent with the
30056 domain-name(s) mentioned in CSR file.
30058 @item @code{authentication-hook} (default: @code{#f})
30059 Command to be run in a shell once for each certificate challenge to be
30060 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
30061 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
30062 contains the validation string and @code{$CERTBOT_TOKEN} contains the
30063 file name of the resource requested when performing an HTTP-01 challenge.
30065 @item @code{cleanup-hook} (default: @code{#f})
30066 Command to be run in a shell once for each certificate challenge that
30067 have been answered by the @code{auth-hook}. For this command, the shell
30068 variables available in the @code{auth-hook} script are still available, and
30069 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
30070 of the @code{auth-hook} script.
30072 @item @code{deploy-hook} (default: @code{#f})
30073 Command to be run in a shell once for each successfully issued
30074 certificate. For this command, the shell variable
30075 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
30076 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
30077 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
30078 contain a space-delimited list of renewed certificate domains (for
30079 example, @samp{"example.com www.example.com"}.
30084 For each @code{certificate-configuration}, the certificate is saved to
30085 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
30086 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
30088 @subsection DNS Services
30089 @cindex DNS (domain name system)
30090 @cindex domain name system (DNS)
30092 The @code{(gnu services dns)} module provides services related to the
30093 @dfn{domain name system} (DNS). It provides a server service for hosting
30094 an @emph{authoritative} DNS server for multiple zones, slave or master.
30095 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
30096 caching and forwarding DNS server for the LAN, which uses
30097 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
30099 @subsubheading Knot Service
30101 An example configuration of an authoritative server for two zones, one master
30105 (define-zone-entries example.org.zone
30106 ;; Name TTL Class Type Data
30107 ("@@" "" "IN" "A" "127.0.0.1")
30108 ("@@" "" "IN" "NS" "ns")
30109 ("ns" "" "IN" "A" "127.0.0.1"))
30111 (define master-zone
30112 (knot-zone-configuration
30113 (domain "example.org")
30115 (origin "example.org")
30116 (entries example.org.zone)))))
30119 (knot-zone-configuration
30120 (domain "plop.org")
30121 (dnssec-policy "default")
30122 (master (list "plop-master"))))
30124 (define plop-master
30125 (knot-remote-configuration
30127 (address (list "208.76.58.171"))))
30131 (services (cons* (service knot-service-type
30132 (knot-configuration
30133 (remotes (list plop-master))
30134 (zones (list master-zone slave-zone))))
30139 @deffn {Scheme Variable} knot-service-type
30140 This is the type for the Knot DNS server.
30142 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
30143 zones, that is to say domain names you would buy from a registrar. This server
30144 is not a resolver, meaning that it can only resolve names for which it is
30145 authoritative. This server can be configured to serve zones as a master server
30146 or a slave server as a per-zone basis. Slave zones will get their data from
30147 masters, and will serve it as an authoritative server. From the point of view
30148 of a resolver, there is no difference between master and slave.
30150 The following data types are used to configure the Knot DNS server:
30153 @deftp {Data Type} knot-key-configuration
30154 Data type representing a key.
30155 This type has the following parameters:
30158 @item @code{id} (default: @code{""})
30159 An identifier for other configuration fields to refer to this key. IDs must
30160 be unique and must not be empty.
30162 @item @code{algorithm} (default: @code{#f})
30163 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
30164 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
30165 and @code{'hmac-sha512}.
30167 @item @code{secret} (default: @code{""})
30168 The secret key itself.
30173 @deftp {Data Type} knot-acl-configuration
30174 Data type representing an Access Control List (ACL) configuration.
30175 This type has the following parameters:
30178 @item @code{id} (default: @code{""})
30179 An identifier for other configuration fields to refer to this key. IDs must be
30180 unique and must not be empty.
30182 @item @code{address} (default: @code{'()})
30183 An ordered list of IP addresses, network subnets, or network ranges represented
30184 with strings. The query must match one of them. Empty value means that
30185 address match is not required.
30187 @item @code{key} (default: @code{'()})
30188 An ordered list of references to keys represented with strings. The string
30189 must match a key ID defined in a @code{knot-key-configuration}. No key means
30190 that a key is not require to match that ACL.
30192 @item @code{action} (default: @code{'()})
30193 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
30194 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
30195 and @code{'update}.
30197 @item @code{deny?} (default: @code{#f})
30198 When true, the ACL defines restrictions. Listed actions are forbidden. When
30199 false, listed actions are allowed.
30204 @deftp {Data Type} zone-entry
30205 Data type representing a record entry in a zone file.
30206 This type has the following parameters:
30209 @item @code{name} (default: @code{"@@"})
30210 The name of the record. @code{"@@"} refers to the origin of the zone. Names
30211 are relative to the origin of the zone. For example, in the @code{example.org}
30212 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
30213 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
30214 refers to @code{ns.example.org}.
30216 @item @code{ttl} (default: @code{""})
30217 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
30219 @item @code{class} (default: @code{"IN"})
30220 The class of the record. Knot currently supports only @code{"IN"} and
30221 partially @code{"CH"}.
30223 @item @code{type} (default: @code{"A"})
30224 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
30225 address), NS (Name Server) and MX (Mail eXchange). Many other types are
30228 @item @code{data} (default: @code{""})
30229 The data contained in the record. For instance an IP address associated with
30230 an A record, or a domain name associated with an NS record. Remember that
30231 domain names are relative to the origin unless they end with a dot.
30236 @deftp {Data Type} zone-file
30237 Data type representing the content of a zone file.
30238 This type has the following parameters:
30241 @item @code{entries} (default: @code{'()})
30242 The list of entries. The SOA record is taken care of, so you don't need to
30243 put it in the list of entries. This list should probably contain an entry
30244 for your primary authoritative DNS server. Other than using a list of entries
30245 directly, you can use @code{define-zone-entries} to define a object containing
30246 the list of entries more easily, that you can later pass to the @code{entries}
30247 field of the @code{zone-file}.
30249 @item @code{origin} (default: @code{""})
30250 The name of your zone. This parameter cannot be empty.
30252 @item @code{ns} (default: @code{"ns"})
30253 The domain of your primary authoritative DNS server. The name is relative to
30254 the origin, unless it ends with a dot. It is mandatory that this primary
30255 DNS server corresponds to an NS record in the zone and that it is associated
30256 to an IP address in the list of entries.
30258 @item @code{mail} (default: @code{"hostmaster"})
30259 An email address people can contact you at, as the owner of the zone. This
30260 is translated as @code{<mail>@@<origin>}.
30262 @item @code{serial} (default: @code{1})
30263 The serial number of the zone. As this is used to keep track of changes by
30264 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
30265 Always increment it when you make a change in your zone.
30267 @item @code{refresh} (default: @code{(* 2 24 3600)})
30268 The frequency at which slaves will do a zone transfer. This value is a number
30269 of seconds. It can be computed by multiplications or with
30270 @code{(string->duration)}.
30272 @item @code{retry} (default: @code{(* 15 60)})
30273 The period after which a slave will retry to contact its master when it fails
30274 to do so a first time.
30276 @item @code{expiry} (default: @code{(* 14 24 3600)})
30277 Default TTL of records. Existing records are considered correct for at most
30278 this amount of time. After this period, resolvers will invalidate their cache
30279 and check again that it still exists.
30281 @item @code{nx} (default: @code{3600})
30282 Default TTL of inexistent records. This delay is usually short because you want
30283 your new domains to reach everyone quickly.
30288 @deftp {Data Type} knot-remote-configuration
30289 Data type representing a remote configuration.
30290 This type has the following parameters:
30293 @item @code{id} (default: @code{""})
30294 An identifier for other configuration fields to refer to this remote. IDs must
30295 be unique and must not be empty.
30297 @item @code{address} (default: @code{'()})
30298 An ordered list of destination IP addresses. Addresses are tried in sequence.
30299 An optional port can be given with the @@ separator. For instance:
30300 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
30302 @item @code{via} (default: @code{'()})
30303 An ordered list of source IP addresses. An empty list will have Knot choose
30304 an appropriate source IP@. An optional port can be given with the @@ separator.
30305 The default is to choose at random.
30307 @item @code{key} (default: @code{#f})
30308 A reference to a key, that is a string containing the identifier of a key
30309 defined in a @code{knot-key-configuration} field.
30314 @deftp {Data Type} knot-keystore-configuration
30315 Data type representing a keystore to hold dnssec keys.
30316 This type has the following parameters:
30319 @item @code{id} (default: @code{""})
30320 The id of the keystore. It must not be empty.
30322 @item @code{backend} (default: @code{'pem})
30323 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
30325 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
30326 The configuration string of the backend. An example for the PKCS#11 is:
30327 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
30328 For the pem backend, the string represents a path in the file system.
30333 @deftp {Data Type} knot-policy-configuration
30334 Data type representing a dnssec policy. Knot DNS is able to automatically
30335 sign your zones. It can either generate and manage your keys automatically or
30336 use keys that you generate.
30338 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
30339 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
30340 zone. In order to be trusted, the KSK needs to be present in the parent zone
30341 (usually a top-level domain). If your registrar supports dnssec, you will
30342 have to send them your KSK's hash so they can add a DS record in their zone.
30343 This is not automated and need to be done each time you change your KSK.
30345 The policy also defines the lifetime of keys. Usually, ZSK can be changed
30346 easily and use weaker cryptographic functions (they use lower parameters) in
30347 order to sign records quickly, so they are changed often. The KSK however
30348 requires manual interaction with the registrar, so they are changed less often
30349 and use stronger parameters because they sign only one record.
30351 This type has the following parameters:
30354 @item @code{id} (default: @code{""})
30355 The id of the policy. It must not be empty.
30357 @item @code{keystore} (default: @code{"default"})
30358 A reference to a keystore, that is a string containing the identifier of a
30359 keystore defined in a @code{knot-keystore-configuration} field. The
30360 @code{"default"} identifier means the default keystore (a kasp database that
30361 was setup by this service).
30363 @item @code{manual?} (default: @code{#f})
30364 Whether the key management is manual or automatic.
30366 @item @code{single-type-signing?} (default: @code{#f})
30367 When @code{#t}, use the Single-Type Signing Scheme.
30369 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
30370 An algorithm of signing keys and issued signatures.
30372 @item @code{ksk-size} (default: @code{256})
30373 The length of the KSK@. Note that this value is correct for the default
30374 algorithm, but would be unsecure for other algorithms.
30376 @item @code{zsk-size} (default: @code{256})
30377 The length of the ZSK@. Note that this value is correct for the default
30378 algorithm, but would be unsecure for other algorithms.
30380 @item @code{dnskey-ttl} (default: @code{'default})
30381 The TTL value for DNSKEY records added into zone apex. The special
30382 @code{'default} value means same as the zone SOA TTL.
30384 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
30385 The period between ZSK publication and the next rollover initiation.
30387 @item @code{propagation-delay} (default: @code{(* 24 3600)})
30388 An extra delay added for each key rollover step. This value should be high
30389 enough to cover propagation of data from the master server to all slaves.
30391 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
30392 A validity period of newly issued signatures.
30394 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
30395 A period how long before a signature expiration the signature will be refreshed.
30397 @item @code{nsec3?} (default: @code{#f})
30398 When @code{#t}, NSEC3 will be used instead of NSEC.
30400 @item @code{nsec3-iterations} (default: @code{5})
30401 The number of additional times the hashing is performed.
30403 @item @code{nsec3-salt-length} (default: @code{8})
30404 The length of a salt field in octets, which is appended to the original owner
30405 name before hashing.
30407 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
30408 The validity period of newly issued salt field.
30413 @deftp {Data Type} knot-zone-configuration
30414 Data type representing a zone served by Knot.
30415 This type has the following parameters:
30418 @item @code{domain} (default: @code{""})
30419 The domain served by this configuration. It must not be empty.
30421 @item @code{file} (default: @code{""})
30422 The file where this zone is saved. This parameter is ignored by master zones.
30423 Empty means default location that depends on the domain name.
30425 @item @code{zone} (default: @code{(zone-file)})
30426 The content of the zone file. This parameter is ignored by slave zones. It
30427 must contain a zone-file record.
30429 @item @code{master} (default: @code{'()})
30430 A list of master remotes. When empty, this zone is a master. When set, this
30431 zone is a slave. This is a list of remotes identifiers.
30433 @item @code{ddns-master} (default: @code{#f})
30434 The main master. When empty, it defaults to the first master in the list of
30437 @item @code{notify} (default: @code{'()})
30438 A list of slave remote identifiers.
30440 @item @code{acl} (default: @code{'()})
30441 A list of acl identifiers.
30443 @item @code{semantic-checks?} (default: @code{#f})
30444 When set, this adds more semantic checks to the zone.
30446 @item @code{zonefile-sync} (default: @code{0})
30447 The delay between a modification in memory and on disk. 0 means immediate
30450 @item @code{zonefile-load} (default: @code{#f})
30451 The way the zone file contents are applied during zone load. Possible values
30455 @item @code{#f} for using the default value from Knot,
30456 @item @code{'none} for not using the zone file at all,
30457 @item @code{'difference} for computing the difference between already available
30458 contents and zone contents and applying it to the current zone contents,
30459 @item @code{'difference-no-serial} for the same as @code{'difference}, but
30460 ignoring the SOA serial in the zone file, while the server takes care of it
30462 @item @code{'whole} for loading zone contents from the zone file.
30465 @item @code{journal-content} (default: @code{#f})
30466 The way the journal is used to store zone and its changes. Possible values
30467 are @code{'none} to not use it at all, @code{'changes} to store changes and
30468 @code{'all} to store contents. @code{#f} does not set this option, so the
30469 default value from Knot is used.
30471 @item @code{max-journal-usage} (default: @code{#f})
30472 The maximum size for the journal on disk. @code{#f} does not set this option,
30473 so the default value from Knot is used.
30475 @item @code{max-journal-depth} (default: @code{#f})
30476 The maximum size of the history. @code{#f} does not set this option, so the
30477 default value from Knot is used.
30479 @item @code{max-zone-size} (default: @code{#f})
30480 The maximum size of the zone file. This limit is enforced for incoming
30481 transfer and updates. @code{#f} does not set this option, so the default
30482 value from Knot is used.
30484 @item @code{dnssec-policy} (default: @code{#f})
30485 A reference to a @code{knot-policy-configuration} record, or the special
30486 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
30489 @item @code{serial-policy} (default: @code{'increment})
30490 A policy between @code{'increment} and @code{'unixtime}.
30495 @deftp {Data Type} knot-configuration
30496 Data type representing the Knot configuration.
30497 This type has the following parameters:
30500 @item @code{knot} (default: @code{knot})
30503 @item @code{run-directory} (default: @code{"/var/run/knot"})
30504 The run directory. This directory will be used for pid file and sockets.
30506 @item @code{includes} (default: @code{'()})
30507 A list of strings or file-like objects denoting other files that must be
30508 included at the top of the configuration file.
30510 @cindex secrets, Knot service
30511 This can be used to manage secrets out-of-band. For example, secret
30512 keys may be stored in an out-of-band file not managed by Guix, and
30513 thus not visible in @file{/gnu/store}---e.g., you could store secret
30514 key configuration in @file{/etc/knot/secrets.conf} and add this file
30515 to the @code{includes} list.
30517 One can generate a secret tsig key (for nsupdate and zone transfers with the
30518 keymgr command from the knot package. Note that the package is not automatically
30519 installed by the service. The following example shows how to generate a new
30523 keymgr -t mysecret > /etc/knot/secrets.conf
30524 chmod 600 /etc/knot/secrets.conf
30527 Also note that the generated key will be named @var{mysecret}, so it is the
30528 name that needs to be used in the @var{key} field of the
30529 @code{knot-acl-configuration} record and in other places that need to refer
30532 It can also be used to add configuration not supported by this interface.
30534 @item @code{listen-v4} (default: @code{"0.0.0.0"})
30535 An ip address on which to listen.
30537 @item @code{listen-v6} (default: @code{"::"})
30538 An ip address on which to listen.
30540 @item @code{listen-port} (default: @code{53})
30541 A port on which to listen.
30543 @item @code{keys} (default: @code{'()})
30544 The list of knot-key-configuration used by this configuration.
30546 @item @code{acls} (default: @code{'()})
30547 The list of knot-acl-configuration used by this configuration.
30549 @item @code{remotes} (default: @code{'()})
30550 The list of knot-remote-configuration used by this configuration.
30552 @item @code{zones} (default: @code{'()})
30553 The list of knot-zone-configuration used by this configuration.
30558 @subsubheading Knot Resolver Service
30560 @deffn {Scheme Variable} knot-resolver-service-type
30561 This is the type of the knot resolver service, whose value should be
30562 an @code{knot-resolver-configuration} object as in this example:
30565 (service knot-resolver-service-type
30566 (knot-resolver-configuration
30567 (kresd-config-file (plain-file "kresd.conf" "
30568 net.listen('192.168.0.1', 5353)
30569 user('knot-resolver', 'knot-resolver')
30570 modules = @{ 'hints > iterate', 'stats', 'predict' @}
30571 cache.size = 100 * MB
30575 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
30578 @deftp {Data Type} knot-resolver-configuration
30579 Data type representing the configuration of knot-resolver.
30582 @item @code{package} (default: @var{knot-resolver})
30583 Package object of the knot DNS resolver.
30585 @item @code{kresd-config-file} (default: %kresd.conf)
30586 File-like object of the kresd configuration file to use, by default it
30587 will listen on @code{127.0.0.1} and @code{::1}.
30589 @item @code{garbage-collection-interval} (default: 1000)
30590 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
30596 @subsubheading Dnsmasq Service
30598 @deffn {Scheme Variable} dnsmasq-service-type
30599 This is the type of the dnsmasq service, whose value should be an
30600 @code{dnsmasq-configuration} object as in this example:
30603 (service dnsmasq-service-type
30604 (dnsmasq-configuration
30606 (servers '("192.168.1.1"))))
30610 @deftp {Data Type} dnsmasq-configuration
30611 Data type representing the configuration of dnsmasq.
30614 @item @code{package} (default: @var{dnsmasq})
30615 Package object of the dnsmasq server.
30617 @item @code{no-hosts?} (default: @code{#f})
30618 When true, don't read the hostnames in /etc/hosts.
30620 @item @code{port} (default: @code{53})
30621 The port to listen on. Setting this to zero completely disables DNS
30622 responses, leaving only DHCP and/or TFTP functions.
30624 @item @code{local-service?} (default: @code{#t})
30625 Accept DNS queries only from hosts whose address is on a local subnet,
30626 ie a subnet for which an interface exists on the server.
30628 @item @code{listen-addresses} (default: @code{'()})
30629 Listen on the given IP addresses.
30631 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
30632 The file to read the IP address of the upstream nameservers from.
30634 @item @code{no-resolv?} (default: @code{#f})
30635 When true, don't read @var{resolv-file}.
30637 @item @code{forward-private-reverse-lookup?} (default: @code{#t})
30638 When false, all reverse lookups for private IP ranges are answered with
30639 "no such domain" rather than being forwarded upstream.
30641 @item @code{query-servers-in-order?} (default: @code{#f})
30642 When true, dnsmasq queries the servers in the same order as they appear
30645 @item @code{servers} (default: @code{'()})
30646 Specify IP address of upstream servers directly.
30648 @item @code{addresses} (default: @code{'()})
30649 For each entry, specify an IP address to return for any host in the
30650 given domains. Queries in the domains are never forwarded and always
30651 replied to with the specified IP address.
30653 This is useful for redirecting hosts locally, for example:
30656 (service dnsmasq-service-type
30657 (dnsmasq-configuration
30659 '(; Redirect to a local web-server.
30660 "/example.org/127.0.0.1"
30661 ; Redirect subdomain to a specific IP.
30662 "/subdomain.example.org/192.168.1.42"))))
30665 Note that rules in @file{/etc/hosts} take precedence over this.
30667 @item @code{cache-size} (default: @code{150})
30668 Set the size of dnsmasq's cache. Setting the cache size to zero
30671 @item @code{negative-cache?} (default: @code{#t})
30672 When false, disable negative caching.
30674 @item @code{cpe-id} (default: @code{#f})
30675 If set, add a CPE (Customer-Premises Equipment) identifier to DNS
30676 queries which are forwarded upstream.
30678 @item @code{tftp-enable?} (default: @code{#f})
30679 Whether to enable the built-in TFTP server.
30681 @item @code{tftp-no-fail?} (default: @code{#f})
30682 If true, does not fail dnsmasq if the TFTP server could not start up.
30684 @item @code{tftp-single-port?} (default: @code{#f})
30685 Whether to use only one single port for TFTP.
30687 @item @code{tftp-secure?} (default: @code{#f})
30688 If true, only files owned by the user running the dnsmasq process are accessible.
30690 If dnsmasq is being run as root, different rules apply:
30691 @code{tftp-secure?} has no effect, but only files which have the
30692 world-readable bit set are accessible.
30694 @item @code{tftp-max} (default: @code{#f})
30695 If set, sets the maximal number of concurrent connections allowed.
30697 @item @code{tftp-mtu} (default: @code{#f})
30698 If set, sets the MTU for TFTP packets to that value.
30700 @item @code{tftp-no-blocksize?} (default: @code{#f})
30701 If true, stops the TFTP server from negotiating the blocksize with a client.
30703 @item @code{tftp-lowercase?} (default: @code{#f})
30704 Whether to convert all filenames in TFTP requests to lowercase.
30706 @item @code{tftp-port-range} (default: @code{#f})
30707 If set, fixes the dynamical ports (one per client) to the given range
30708 (@code{"<start>,<end>"}).
30710 @item @code{tftp-root} (default: @code{/var/empty,lo})
30711 Look for files to transfer using TFTP relative to the given directory.
30712 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
30713 getting outside the specified root. Absolute paths (starting with @samp{/}) are
30714 allowed, but they must be within the TFTP-root. If the optional interface
30715 argument is given, the directory is only used for TFTP requests via that
30718 @item @code{tftp-unique-root} (default: @code{#f})
30719 If set, add the IP or hardware address of the TFTP client as a path component
30720 on the end of the TFTP-root. Only valid if a TFTP root is set and the
30721 directory exists. Defaults to adding IP address (in standard dotted-quad
30724 For instance, if @option{--tftp-root} is @samp{/tftp} and client
30725 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
30726 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
30727 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
30728 append the MAC address instead, using lowercase zero padded digits
30729 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
30730 resolving MAC addresses is only possible if the client is in the local
30731 network or obtained a DHCP lease from dnsmasq.
30736 @subsubheading ddclient Service
30739 The ddclient service described below runs the ddclient daemon, which takes
30740 care of automatically updating DNS entries for service providers such as
30741 @uref{https://dyn.com/dns/, Dyn}.
30743 The following example show instantiates the service with its default
30747 (service ddclient-service-type)
30750 Note that ddclient needs to access credentials that are stored in a
30751 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
30752 @code{secret-file} below). You are expected to create this file manually, in
30753 an ``out-of-band'' fashion (you @emph{could} make this file part of the
30754 service configuration, for instance by using @code{plain-file}, but it will be
30755 world-readable @i{via} @file{/gnu/store}). See the examples in the
30756 @file{share/ddclient} directory of the @code{ddclient} package.
30758 @c %start of fragment
30760 Available @code{ddclient-configuration} fields are:
30762 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
30763 The ddclient package.
30767 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
30768 The period after which ddclient will retry to check IP and domain name.
30770 Defaults to @samp{300}.
30774 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
30775 Use syslog for the output.
30777 Defaults to @samp{#t}.
30781 @deftypevr {@code{ddclient-configuration} parameter} string mail
30784 Defaults to @samp{"root"}.
30788 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
30789 Mail failed update to user.
30791 Defaults to @samp{"root"}.
30795 @deftypevr {@code{ddclient-configuration} parameter} string pid
30796 The ddclient PID file.
30798 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
30802 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
30803 Enable SSL support.
30805 Defaults to @samp{#t}.
30809 @deftypevr {@code{ddclient-configuration} parameter} string user
30810 Specifies the user name or ID that is used when running ddclient
30813 Defaults to @samp{"ddclient"}.
30817 @deftypevr {@code{ddclient-configuration} parameter} string group
30818 Group of the user who will run the ddclient program.
30820 Defaults to @samp{"ddclient"}.
30824 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
30825 Secret file which will be appended to @file{ddclient.conf} file. This
30826 file contains credentials for use by ddclient. You are expected to
30827 create it manually.
30829 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
30833 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
30834 Extra options will be appended to @file{ddclient.conf} file.
30836 Defaults to @samp{()}.
30841 @c %end of fragment
30844 @subsection VNC Services
30845 @cindex VNC (virtual network computing)
30846 @cindex XDMCP (x display manager control protocol)
30848 The @code{(gnu services vnc)} module provides services related to
30849 @dfn{Virtual Network Computing} (VNC), which makes it possible to
30850 locally use graphical Xorg applications running on a remote machine.
30851 Combined with a graphical manager that supports the @dfn{X Display
30852 Manager Control Protocol}, such as GDM (@pxref{gdm}) or LightDM
30853 (@pxref{lightdm}), it is possible to remote an entire desktop for a
30854 multi-user environment.
30856 @subsubheading Xvnc
30858 Xvnc is a VNC server that spawns its own X window server; which means it
30859 can run on headless servers. The Xvnc implementations provided by the
30860 @code{tigervnc-server} and @code{turbovnc} aim to be fast and efficient.
30862 @defvar {Scheme Variable} xvnc-service-type
30864 The @code{xvnc-server-type} service can be configured via the
30865 @code{xvnc-configuration} record, documented below. A second virtual
30866 display could be made available on a remote machine for via the
30867 following configuration:
30871 (service xvnc-service-type (xvnc-configuration (display-number 10)
30874 As a demonstration, the @command{xclock} command could then be started
30875 on the remote machine on display number 10, and it could be display
30876 locally via the @command{vncviewer} command:
30878 # Start xclock on the remote machine.
30879 ssh -L5910:localhost:5910 -- guix shell xclock -- env DISPLAY=:10 xclock
30880 # Access it via VNC.
30881 guix shell tigervnc-client -- vncviewer localhost:5910
30884 The following configuration combines XDMCP and Inetd to allow multiple
30885 users to concurrently use the remote system, login in graphically via
30886 the GDM display manager:
30893 (service xvnc-service-type (xvnc-configuration
30898 (modify-services %desktop-services
30899 (gdm-service-type config => (gdm-configuration
30905 A remote user could then connect to it by using the @command{vncviewer}
30906 command or a compatible VNC client and start a desktop session of their
30909 vncviewer remote-host:5905
30913 Unless your machine is in a controlled environment, for security
30914 reasons, the @code{localhost?} configuration of the
30915 @code{xvnc-configuration} record should be left to its default @code{#t}
30916 value and exposed via a secure means such as an SSH port forward. The
30917 XDMCP port, UDP 177 should also be blocked from the outside by a
30918 firewall, as it is not a secure protocol and can expose login
30919 credentials in clear.
30922 @c Use (configuration->documentation 'xvnc-configuration) to regenerate
30923 @c the documentation.
30924 @c %start of fragment
30925 @deftp {Data Type} xvnc-configuration
30926 Available @code{xvnc-configuration} fields are:
30929 @item @code{xvnc} (default: @code{tigervnc-server}) (type: file-like)
30930 The package that provides the Xvnc binary.
30932 @item @code{display-number} (default: @code{0}) (type: number)
30933 The display number used by Xvnc. You should set this to a number not
30934 already used a Xorg server.
30936 @item @code{geometry} (default: @code{"1024x768"}) (type: string)
30937 The size of the desktop to be created.
30939 @item @code{depth} (default: @code{24}) (type: color-depth)
30940 The pixel depth in bits of the desktop to be created. Accepted values
30943 @item @code{port} (type: maybe-port)
30944 The port on which to listen for connections from viewers. When left
30945 unspecified, it defaults to 5900 plus the display number.
30947 @item @code{ipv4?} (default: @code{#t}) (type: boolean)
30948 Use IPv4 for incoming and outgoing connections.
30950 @item @code{ipv6?} (default: @code{#t}) (type: boolean)
30951 Use IPv6 for incoming and outgoing connections.
30953 @item @code{password-file} (type: maybe-string)
30954 The password file to use, if any. Refer to vncpasswd(1) to learn how to
30955 generate such a file.
30957 @item @code{xdmcp?} (default: @code{#f}) (type: boolean)
30958 Query the XDMCP server for a session. This enables users to log in a
30959 desktop session from the login manager screen. For a multiple users
30960 scenario, you'll want to enable the @code{inetd?} option as well, so
30961 that each connection to the VNC server is handled separately rather than
30964 @item @code{inetd?} (default: @code{#f}) (type: boolean)
30965 Use an Inetd-style service, which runs the Xvnc server on demand.
30967 @item @code{frame-rate} (default: @code{60}) (type: number)
30968 The maximum number of updates per second sent to each client.
30970 @item @code{security-types} (default: @code{("None")}) (type: security-types)
30971 The allowed security schemes to use for incoming connections. The
30972 default is "None", which is safe given that Xvnc is configured to
30973 authenticate the user via the display manager, and only for local
30974 connections. Accepted values are any of the following: ("None"
30975 "VncAuth" "Plain" "TLSNone" "TLSVnc" "TLSPlain" "X509None" "X509Vnc")
30977 @item @code{localhost?} (default: @code{#t}) (type: boolean)
30978 Only allow connections from the same machine. It is set to #true by
30979 default for security, which means SSH or another secure means should be
30980 used to expose the remote port.
30982 @item @code{log-level} (default: @code{30}) (type: log-level)
30983 The log level, a number between 0 and 100, 100 meaning most verbose
30984 output. The log messages are output to syslog.
30986 @item @code{extra-options} (default: @code{()}) (type: strings)
30987 This can be used to provide extra Xvnc options not exposed via this
30988 <xvnc-configuration> record.
30993 @c %end of fragment
30996 @subsection VPN Services
30997 @cindex VPN (virtual private network)
30998 @cindex virtual private network (VPN)
31000 The @code{(gnu services vpn)} module provides services related to
31001 @dfn{virtual private networks} (VPNs).
31003 @subsubheading Bitmask
31005 @defvr {Scheme Variable} bitmask-service-type
31006 A service type for the @uref{https://bitmask.net, Bitmask} VPN client. It makes
31007 the client available in the system and loads its polkit policy. Please note that
31008 the client expects an active polkit-agent, which is either run by your
31009 desktop-environment or should be run manually.
31012 @subsubheading OpenVPN
31014 It provides a @emph{client} service for your machine to connect to a
31015 VPN, and a @emph{server} service for your machine to host a VPN@.
31017 @deffn {Scheme Procedure} openvpn-client-service @
31018 [#:config (openvpn-client-configuration)]
31020 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
31023 @deffn {Scheme Procedure} openvpn-server-service @
31024 [#:config (openvpn-server-configuration)]
31026 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
31028 Both can be run simultaneously.
31031 @c %automatically generated documentation
31033 @deftp {Data Type} openvpn-client-configuration
31034 Available @code{openvpn-client-configuration} fields are:
31037 @item @code{openvpn} (default: @code{openvpn}) (type: file-like)
31038 The OpenVPN package.
31040 @item @code{pid-file} (default: @code{"/var/run/openvpn/openvpn.pid"}) (type: string)
31041 The OpenVPN pid file.
31043 @item @code{proto} (default: @code{udp}) (type: proto)
31044 The protocol (UDP or TCP) used to open a channel between clients and
31047 @item @code{dev} (default: @code{tun}) (type: dev)
31048 The device type used to represent the VPN connection.
31050 @item @code{ca} (default: @code{"/etc/openvpn/ca.crt"}) (type: maybe-string)
31051 The certificate authority to check connections against.
31053 @item @code{cert} (default: @code{"/etc/openvpn/client.crt"}) (type: maybe-string)
31054 The certificate of the machine the daemon is running on. It should be
31055 signed by the authority given in @code{ca}.
31057 @item @code{key} (default: @code{"/etc/openvpn/client.key"}) (type: maybe-string)
31058 The key of the machine the daemon is running on. It must be the key
31059 whose certificate is @code{cert}.
31061 @item @code{comp-lzo?} (default: @code{#t}) (type: boolean)
31062 Whether to use the lzo compression algorithm.
31064 @item @code{persist-key?} (default: @code{#t}) (type: boolean)
31065 Don't re-read key files across SIGUSR1 or --ping-restart.
31067 @item @code{persist-tun?} (default: @code{#t}) (type: boolean)
31068 Don't close and reopen TUN/TAP device or run up/down scripts across
31069 SIGUSR1 or --ping-restart restarts.
31071 @item @code{fast-io?} (default: @code{#f}) (type: boolean)
31072 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
31073 poll/epoll/select prior to the write operation.
31075 @item @code{verbosity} (default: @code{3}) (type: number)
31078 @item @code{tls-auth} (default: @code{#f}) (type: tls-auth-client)
31079 Add an additional layer of HMAC authentication on top of the TLS control
31080 channel to protect against DoS attacks.
31082 @item @code{auth-user-pass} (type: maybe-string)
31083 Authenticate with server using username/password. The option is a file
31084 containing username/password on 2 lines. Do not use a file-like object
31085 as it would be added to the store and readable by any user.
31087 @item @code{verify-key-usage?} (default: @code{#t}) (type: key-usage)
31088 Whether to check the server certificate has server usage extension.
31090 @item @code{bind?} (default: @code{#f}) (type: bind)
31091 Bind to a specific local port number.
31093 @item @code{resolv-retry?} (default: @code{#t}) (type: resolv-retry)
31094 Retry resolving server address.
31096 @item @code{remote} (default: @code{()}) (type: openvpn-remote-list)
31097 A list of remote servers to connect to.
31099 @deftp {Data Type} openvpn-remote-configuration
31100 Available @code{openvpn-remote-configuration} fields are:
31103 @item @code{name} (default: @code{"my-server"}) (type: string)
31106 @item @code{port} (default: @code{1194}) (type: number)
31107 Port number the server listens to.
31117 @c %end of automatic openvpn-client documentation
31119 @c %automatically generated documentation
31121 @deftp {Data Type} openvpn-server-configuration
31122 Available @code{openvpn-server-configuration} fields are:
31125 @item @code{openvpn} (default: @code{openvpn}) (type: file-like)
31126 The OpenVPN package.
31128 @item @code{pid-file} (default: @code{"/var/run/openvpn/openvpn.pid"}) (type: string)
31129 The OpenVPN pid file.
31131 @item @code{proto} (default: @code{udp}) (type: proto)
31132 The protocol (UDP or TCP) used to open a channel between clients and
31135 @item @code{dev} (default: @code{tun}) (type: dev)
31136 The device type used to represent the VPN connection.
31138 @item @code{ca} (default: @code{"/etc/openvpn/ca.crt"}) (type: maybe-string)
31139 The certificate authority to check connections against.
31141 @item @code{cert} (default: @code{"/etc/openvpn/client.crt"}) (type: maybe-string)
31142 The certificate of the machine the daemon is running on. It should be
31143 signed by the authority given in @code{ca}.
31145 @item @code{key} (default: @code{"/etc/openvpn/client.key"}) (type: maybe-string)
31146 The key of the machine the daemon is running on. It must be the key
31147 whose certificate is @code{cert}.
31149 @item @code{comp-lzo?} (default: @code{#t}) (type: boolean)
31150 Whether to use the lzo compression algorithm.
31152 @item @code{persist-key?} (default: @code{#t}) (type: boolean)
31153 Don't re-read key files across SIGUSR1 or --ping-restart.
31155 @item @code{persist-tun?} (default: @code{#t}) (type: boolean)
31156 Don't close and reopen TUN/TAP device or run up/down scripts across
31157 SIGUSR1 or --ping-restart restarts.
31159 @item @code{fast-io?} (default: @code{#f}) (type: boolean)
31160 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
31161 poll/epoll/select prior to the write operation.
31163 @item @code{verbosity} (default: @code{3}) (type: number)
31166 @item @code{tls-auth} (default: @code{#f}) (type: tls-auth-server)
31167 Add an additional layer of HMAC authentication on top of the TLS control
31168 channel to protect against DoS attacks.
31170 @item @code{port} (default: @code{1194}) (type: number)
31171 Specifies the port number on which the server listens.
31173 @item @code{server} (default: @code{"10.8.0.0 255.255.255.0"}) (type: ip-mask)
31174 An ip and mask specifying the subnet inside the virtual network.
31176 @item @code{server-ipv6} (default: @code{#f}) (type: cidr6)
31177 A CIDR notation specifying the IPv6 subnet inside the virtual network.
31179 @item @code{dh} (default: @code{"/etc/openvpn/dh2048.pem"}) (type: string)
31180 The Diffie-Hellman parameters file.
31182 @item @code{ifconfig-pool-persist} (default: @code{"/etc/openvpn/ipp.txt"}) (type: string)
31183 The file that records client IPs.
31185 @item @code{redirect-gateway?} (default: @code{#f}) (type: gateway)
31186 When true, the server will act as a gateway for its clients.
31188 @item @code{client-to-client?} (default: @code{#f}) (type: boolean)
31189 When true, clients are allowed to talk to each other inside the VPN.
31191 @item @code{keepalive} (default: @code{(10 120)}) (type: keepalive)
31192 Causes ping-like messages to be sent back and forth over the link so
31193 that each side knows when the other side has gone down. @code{keepalive}
31194 requires a pair. The first element is the period of the ping sending,
31195 and the second element is the timeout before considering the other side
31198 @item @code{max-clients} (default: @code{100}) (type: number)
31199 The maximum number of clients.
31201 @item @code{status} (default: @code{"/var/run/openvpn/status"}) (type: string)
31202 The status file. This file shows a small report on current connection.
31203 It is truncated and rewritten every minute.
31205 @item @code{client-config-dir} (default: @code{()}) (type: openvpn-ccd-list)
31206 The list of configuration for some clients.
31212 @c %end of automatic openvpn-server documentation
31214 @subheading strongSwan
31216 Currently, the strongSwan service only provides legacy-style configuration with
31217 @file{ipsec.conf} and @file{ipsec.secrets} files.
31219 @defvr {Scheme Variable} strongswan-service-type
31220 A service type for configuring strongSwan for IPsec @acronym{VPN,
31221 Virtual Private Networking}. Its value must be a
31222 @code{strongswan-configuration} record as in this example:
31225 (service strongswan-service-type
31226 (strongswan-configuration
31227 (ipsec-conf "/etc/ipsec.conf")
31228 (ipsec-secrets "/etc/ipsec.secrets")))
31233 @deftp {Data Type} strongswan-configuration
31234 Data type representing the configuration of the StrongSwan service.
31237 @item @code{strongswan}
31238 The strongSwan package to use for this service.
31240 @item @code{ipsec-conf} (default: @code{#f})
31241 The file name of your @file{ipsec.conf}. If not @code{#f}, then this and
31242 @code{ipsec-secrets} must both be strings.
31244 @item @code{ipsec-secrets} (default @code{#f})
31245 The file name of your @file{ipsec.secrets}. If not @code{#f}, then this and
31246 @code{ipsec-conf} must both be strings.
31251 @subsubheading Wireguard
31253 @defvr {Scheme Variable} wireguard-service-type
31254 A service type for a Wireguard tunnel interface. Its value must be a
31255 @code{wireguard-configuration} record as in this example:
31258 (service wireguard-service-type
31259 (wireguard-configuration
31264 (endpoint "my.wireguard.com:51820")
31265 (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
31266 (allowed-ips '("10.0.0.2/32")))))))
31271 @deftp {Data Type} wireguard-configuration
31272 Data type representing the configuration of the Wireguard service.
31275 @item @code{wireguard}
31276 The wireguard package to use for this service.
31278 @item @code{interface} (default: @code{"wg0"})
31279 The interface name for the VPN.
31281 @item @code{addresses} (default: @code{'("10.0.0.1/32")})
31282 The IP addresses to be assigned to the above interface.
31284 @item @code{port} (default: @code{51820})
31285 The port on which to listen for incoming connections.
31287 @item @code{dns} (default: @code{#f})
31288 The DNS server(s) to announce to VPN clients via DHCP.
31290 @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
31291 The private key file for the interface. It is automatically generated if
31292 the file does not exist.
31294 @item @code{peers} (default: @code{'()})
31295 The authorized peers on this interface. This is a list of
31296 @var{wireguard-peer} records.
31301 @deftp {Data Type} wireguard-peer
31302 Data type representing a Wireguard peer attached to a given interface.
31308 @item @code{endpoint} (default: @code{#f})
31309 The optional endpoint for the peer, such as
31310 @code{"demo.wireguard.com:51820"}.
31312 @item @code{public-key}
31313 The peer public-key represented as a base64 string.
31315 @item @code{allowed-ips}
31316 A list of IP addresses from which incoming traffic for this peer is
31317 allowed and to which incoming traffic for this peer is directed.
31319 @item @code{keep-alive} (default: @code{#f})
31320 An optional time interval in seconds. A packet will be sent to the
31321 server endpoint once per time interval. This helps receiving
31322 incoming connections from this peer when you are behind a NAT or
31328 @node Network File System
31329 @subsection Network File System
31332 The @code{(gnu services nfs)} module provides the following services,
31333 which are most commonly used in relation to mounting or exporting
31334 directory trees as @dfn{network file systems} (NFS).
31336 While it is possible to use the individual components that together make
31337 up a Network File System service, we recommended to configure an NFS
31338 server with the @code{nfs-service-type}.
31340 @subsubheading NFS Service
31341 @cindex NFS, server
31343 The NFS service takes care of setting up all NFS component services,
31344 kernel configuration file systems, and installs configuration files in
31345 the locations that NFS expects.
31347 @defvr {Scheme Variable} nfs-service-type
31348 A service type for a complete NFS server.
31351 @deftp {Data Type} nfs-configuration
31352 This data type represents the configuration of the NFS service and all
31355 It has the following parameters:
31357 @item @code{nfs-utils} (default: @code{nfs-utils})
31358 The nfs-utils package to use.
31360 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
31361 If a list of string values is provided, the @command{rpc.nfsd} daemon
31362 will be limited to supporting the given versions of the NFS protocol.
31364 @item @code{exports} (default: @code{'()})
31365 This is a list of directories the NFS server should export. Each entry
31366 is a list consisting of two elements: a directory name and a string
31367 containing all options. This is an example in which the directory
31368 @file{/export} is served to all NFS clients as a read-only share:
31374 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
31377 @item @code{rpcmountd-port} (default: @code{#f})
31378 The network port that the @command{rpc.mountd} daemon should use.
31380 @item @code{rpcstatd-port} (default: @code{#f})
31381 The network port that the @command{rpc.statd} daemon should use.
31383 @item @code{rpcbind} (default: @code{rpcbind})
31384 The rpcbind package to use.
31386 @item @code{idmap-domain} (default: @code{"localdomain"})
31387 The local NFSv4 domain name.
31389 @item @code{nfsd-port} (default: @code{2049})
31390 The network port that the @command{nfsd} daemon should use.
31392 @item @code{nfsd-threads} (default: @code{8})
31393 The number of threads used by the @command{nfsd} daemon.
31395 @item @code{nfsd-tcp?} (default: @code{#t})
31396 Whether the @command{nfsd} daemon should listen on a TCP socket.
31398 @item @code{nfsd-udp?} (default: @code{#f})
31399 Whether the @command{nfsd} daemon should listen on a UDP socket.
31401 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31402 The directory where the pipefs file system is mounted.
31404 @item @code{debug} (default: @code{'()"})
31405 A list of subsystems for which debugging output should be enabled. This
31406 is a list of symbols. Any of these symbols are valid: @code{nfsd},
31407 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
31411 If you don't need a complete NFS service or prefer to build it yourself
31412 you can use the individual component services that are documented below.
31414 @subsubheading RPC Bind Service
31417 The RPC Bind service provides a facility to map program numbers into
31418 universal addresses.
31419 Many NFS related services use this facility. Hence it is automatically
31420 started when a dependent service starts.
31422 @defvr {Scheme Variable} rpcbind-service-type
31423 A service type for the RPC portmapper daemon.
31427 @deftp {Data Type} rpcbind-configuration
31428 Data type representing the configuration of the RPC Bind Service.
31429 This type has the following parameters:
31431 @item @code{rpcbind} (default: @code{rpcbind})
31432 The rpcbind package to use.
31434 @item @code{warm-start?} (default: @code{#t})
31435 If this parameter is @code{#t}, then the daemon will read a
31436 state file on startup thus reloading state information saved by a previous
31442 @subsubheading Pipefs Pseudo File System
31446 The pipefs file system is used to transfer NFS related data
31447 between the kernel and user space programs.
31449 @defvr {Scheme Variable} pipefs-service-type
31450 A service type for the pipefs pseudo file system.
31453 @deftp {Data Type} pipefs-configuration
31454 Data type representing the configuration of the pipefs pseudo file system service.
31455 This type has the following parameters:
31457 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31458 The directory to which the file system is to be attached.
31463 @subsubheading GSS Daemon Service
31466 @cindex global security system
31468 The @dfn{global security system} (GSS) daemon provides strong security for RPC
31470 Before exchanging RPC requests an RPC client must establish a security
31471 context. Typically this is done using the Kerberos command @command{kinit}
31472 or automatically at login time using PAM services (@pxref{Kerberos Services}).
31474 @defvr {Scheme Variable} gss-service-type
31475 A service type for the Global Security System (GSS) daemon.
31478 @deftp {Data Type} gss-configuration
31479 Data type representing the configuration of the GSS daemon service.
31480 This type has the following parameters:
31482 @item @code{nfs-utils} (default: @code{nfs-utils})
31483 The package in which the @command{rpc.gssd} command is to be found.
31485 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31486 The directory where the pipefs file system is mounted.
31492 @subsubheading IDMAP Daemon Service
31494 @cindex name mapper
31496 The idmap daemon service provides mapping between user IDs and user names.
31497 Typically it is required in order to access file systems mounted via NFSv4.
31499 @defvr {Scheme Variable} idmap-service-type
31500 A service type for the Identity Mapper (IDMAP) daemon.
31503 @deftp {Data Type} idmap-configuration
31504 Data type representing the configuration of the IDMAP daemon service.
31505 This type has the following parameters:
31507 @item @code{nfs-utils} (default: @code{nfs-utils})
31508 The package in which the @command{rpc.idmapd} command is to be found.
31510 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
31511 The directory where the pipefs file system is mounted.
31513 @item @code{domain} (default: @code{#f})
31514 The local NFSv4 domain name.
31515 This must be a string or @code{#f}.
31516 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
31518 @item @code{verbosity} (default: @code{0})
31519 The verbosity level of the daemon.
31524 @node Samba Services, Continuous Integration, Network File System, Services
31525 @subsection Samba Services
31529 The @code{(gnu services samba)} module provides service definitions for
31530 Samba as well as additional helper services. Currently it provides the
31531 following services.
31533 @subsubheading Samba
31535 @uref{https://www.samba.org, Samba} provides network shares for folders
31536 and printers using the SMB/CIFS protocol commonly used on Windows. It
31537 can also act as an Active Directory Domain Controller (AD DC) for other
31538 hosts in an heterougenious network with different types of Computer
31541 @defvar {Scheme variable} samba-service-type
31543 The service type to enable the samba services @code{samba}, @code{nmbd},
31544 @code{smbd} and @code{winbindd}. By default this service type does not
31545 run any of the Samba daemons; they must be enabled individually.
31547 Below is a basic example that configures a simple, anonymous
31548 (unauthenticated) Samba file share exposing the @file{/public}
31552 The @file{/public} directory and its contents must be world
31553 readable/writable, so you'll want to run @samp{chmod -R 777 /public} on
31558 Such a Samba configuration should only be used in controlled
31559 environments, and you should not share any private files using it, as
31560 anyone connecting to your network would be able to access them.
31564 (service samba-service-type (samba-configuration
31566 (config-file (plain-file "smb.conf" "\
31568 map to guest = Bad User
31569 logging = syslog@@1
31576 guest only = yes\n"))))
31581 @deftp{Data Type} samba-service-configuration
31582 Configuration record for the Samba suite.
31585 @item @code{package} (default: @code{samba})
31586 The samba package to use.
31588 @item @code{config-file} (default: @code{#f})
31589 The config file to use. To learn about its syntax, run @samp{man
31592 @item @code{enable-samba?} (default: @code{#f})
31593 Enable the @code{samba} daemon.
31595 @item @code{enable-smbd?} (default: @code{#f})
31596 Enable the @code{smbd} daemon.
31598 @item @code{enable-nmbd?} (default: @code{#f})
31599 Enable the @code{nmbd} daemon.
31601 @item @code{enable-winbindd?} (default: @code{#f})
31602 Enable the @code{winbindd} daemon.
31607 @cindex wsdd, Web service discovery daemon
31608 @subsubheading Web Service Discovery Daemon
31610 The @acronym{WSDD, Web Service Discovery daemon} implements the
31611 @uref{http://docs.oasis-open.org/ws-dd/discovery/1.1/os/wsdd-discovery-1.1-spec-os.html,
31612 Web Services Dynamic Discovery} protocol that enables host discovery
31613 over Multicast DNS, similar to what Avahi does. It is a drop-in
31614 replacement for SMB hosts that have had SMBv1 disabled for security
31617 @defvr {Scheme Variable} wsdd-service-type
31618 Service type for the WSD host daemon. The value for
31619 this service type is a @code{wsdd-configuration} record. The details
31620 for the @code{wsdd-configuration} record type are given below.
31623 @deftp {Data Type} wsdd-configuration
31624 This data type represents the configuration for the wsdd service.
31628 @item @code{package} (default: @code{wsdd})
31629 The wsdd package to use.
31631 @item @code{ipv4only?} (default: @code{#f})
31632 Only listen to IPv4 addresses.
31634 @item @code{ipv6only} (default: @code{#f})
31635 Only listen to IPv6 addresses. Please note: Activating both options is
31636 not possible, since there would be no IP versions to listen to.
31638 @item @code{chroot} (default: @code{#f})
31639 Chroot into a separate directory to prevent access to other directories.
31640 This is to increase security in case there is a vulnerability in
31643 @item @code{hop-limit} (default: @code{1})
31644 Limit to the level of hops for multicast packets. The default is
31645 @var{1} which should prevent packets from leaving the local network.
31647 @item @code{interface} (default: @code{'()})
31648 Limit to the given list of interfaces to listen to. By default wsdd
31649 will listen to all interfaces. Except the loopback interface is never
31652 @item @code{uuid-device} (default: @code{#f})
31653 The WSD protocol requires a device to have a UUID. Set this to manually
31654 assign the service a UUID.
31656 @item @code{domain} (default: @code{#f})
31657 Notify this host is a member of an Active Directory.
31659 @item @code{host-name} (default: @code{#f})
31660 Manually set the hostname rather than letting @command{wsdd} inherit
31661 this host's hostname. Only the host name part of a possible FQDN will
31662 be used in the default case.
31664 @item @code{preserve-case?} (default: @code{#f})
31665 By default @command{wsdd} will convert the hostname in workgroup to all
31666 uppercase. The opposite is true for hostnames in domains. Setting this
31667 parameter will preserve case.
31669 @item @code{workgroup} (default: @var{"WORKGROUP"})
31670 Change the name of the workgroup. By default @command{wsdd} reports
31671 this host being member of a workgroup.
31676 @node Continuous Integration
31677 @subsection Continuous Integration
31679 @cindex continuous integration
31680 @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
31681 integration tool for Guix. It can be used both for development and for
31682 providing substitutes to others (@pxref{Substitutes}).
31684 The @code{(gnu services cuirass)} module provides the following service.
31686 @defvr {Scheme Procedure} cuirass-service-type
31687 The type of the Cuirass service. Its value must be a
31688 @code{cuirass-configuration} object, as described below.
31691 To add build jobs, you have to set the @code{specifications} field of
31692 the configuration. For instance, the following example will build all
31693 the packages provided by the @code{my-channel} channel.
31696 (define %cuirass-specs
31697 #~(list (specification
31698 (name "my-channel")
31699 (build '(channels my-channel))
31703 (url "https://my-channel.git"))
31704 %default-channels)))))
31706 (service cuirass-service-type
31707 (cuirass-configuration
31708 (specifications %cuirass-specs)))
31711 To build the @code{linux-libre} package defined by the default Guix
31712 channel, one can use the following configuration.
31715 (define %cuirass-specs
31716 #~(list (specification
31718 (build '(packages "linux-libre")))))
31720 (service cuirass-service-type
31721 (cuirass-configuration
31722 (specifications %cuirass-specs)))
31725 The other configuration possibilities, as well as the specification
31726 record itself are described in the Cuirass manual
31727 (@pxref{Specifications,,, cuirass, Cuirass}).
31729 While information related to build jobs is located directly in the
31730 specifications, global settings for the @command{cuirass} process are
31731 accessible in other @code{cuirass-configuration} fields.
31733 @deftp {Data Type} cuirass-configuration
31734 Data type representing the configuration of Cuirass.
31737 @item @code{cuirass} (default: @code{cuirass})
31738 The Cuirass package to use.
31740 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
31741 Location of the log file.
31743 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
31744 Location of the log file used by the web interface.
31746 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
31747 Location of the repository cache.
31749 @item @code{user} (default: @code{"cuirass"})
31750 Owner of the @code{cuirass} process.
31752 @item @code{group} (default: @code{"cuirass"})
31753 Owner's group of the @code{cuirass} process.
31755 @item @code{interval} (default: @code{60})
31756 Number of seconds between the poll of the repositories followed by the
31759 @item @code{parameters} (default: @code{#f})
31760 Read parameters from the given @var{parameters} file. The supported
31761 parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
31763 @item @code{remote-server} (default: @code{#f})
31764 A @code{cuirass-remote-server-configuration} record to use the build
31765 remote mechanism or @code{#f} to use the default build mechanism.
31767 @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
31768 Use @var{database} as the database containing the jobs and the past
31769 build results. Since Cuirass uses PostgreSQL as a database engine,
31770 @var{database} must be a string such as @code{"dbname=cuirass
31773 @item @code{port} (default: @code{8081})
31774 Port number used by the HTTP server.
31776 @item @code{host} (default: @code{"localhost"})
31777 Listen on the network interface for @var{host}. The default is to
31778 accept connections from localhost.
31780 @item @code{specifications} (default: @code{#~'()})
31781 A gexp (@pxref{G-Expressions}) that evaluates to a list of
31782 specifications records. The specification record is described in the
31783 Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
31785 @item @code{use-substitutes?} (default: @code{#f})
31786 This allows using substitutes to avoid building every dependencies of a job
31789 @item @code{one-shot?} (default: @code{#f})
31790 Only evaluate specifications and build derivations once.
31792 @item @code{fallback?} (default: @code{#f})
31793 When substituting a pre-built binary fails, fall back to building
31796 @item @code{extra-options} (default: @code{'()})
31797 Extra options to pass when running the Cuirass processes.
31802 @cindex remote build
31803 @subsubheading Cuirass remote building
31805 Cuirass supports two mechanisms to build derivations.
31808 @item Using the local Guix daemon.
31809 This is the default build mechanism. Once the build jobs are
31810 evaluated, they are sent to the local Guix daemon. Cuirass then
31811 listens to the Guix daemon output to detect the various build events.
31813 @item Using the remote build mechanism.
31814 The build jobs are not submitted to the local Guix daemon. Instead, a
31815 remote server dispatches build requests to the connect remote workers,
31816 according to the build priorities.
31820 To enable this build mode a @code{cuirass-remote-server-configuration}
31821 record must be passed as @code{remote-server} argument of the
31822 @code{cuirass-configuration} record. The
31823 @code{cuirass-remote-server-configuration} record is described below.
31825 This build mode scales way better than the default build mode. This is
31826 the build mode that is used on the GNU Guix build farm at
31827 @url{https://ci.guix.gnu.org}. It should be preferred when using
31828 Cuirass to build large amount of packages.
31830 @deftp {Data Type} cuirass-remote-server-configuration
31831 Data type representing the configuration of the Cuirass remote-server.
31834 @item @code{backend-port} (default: @code{5555})
31835 The TCP port for communicating with @code{remote-worker} processes
31836 using ZMQ. It defaults to @code{5555}.
31838 @item @code{log-port} (default: @code{5556})
31839 The TCP port of the log server. It defaults to @code{5556}.
31841 @item @code{publish-port} (default: @code{5557})
31842 The TCP port of the publish server. It defaults to @code{5557}.
31844 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
31845 Location of the log file.
31847 @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
31848 Use @var{cache} directory to cache build log files.
31850 @item @code{trigger-url} (default: @code{#f})
31851 Once a substitute is successfully fetched, trigger substitute baking at
31854 @item @code{publish?} (default: @code{#t})
31855 If set to false, do not start a publish server and ignore the
31856 @code{publish-port} argument. This can be useful if there is already a
31857 standalone publish server standing next to the remote server.
31859 @item @code{public-key}
31860 @item @code{private-key}
31861 Use the specific @var{file}s as the public/private key pair used to sign
31862 the store items being published.
31867 At least one remote worker must also be started on any machine of the
31868 local network to actually perform the builds and report their status.
31870 @deftp {Data Type} cuirass-remote-worker-configuration
31871 Data type representing the configuration of the Cuirass remote-worker.
31874 @item @code{cuirass} (default: @code{cuirass})
31875 The Cuirass package to use.
31877 @item @code{workers} (default: @code{1})
31878 Start @var{workers} parallel workers.
31880 @item @code{server} (default: @code{#f})
31881 Do not use Avahi discovery and connect to the given @code{server} IP
31884 @item @code{systems} (default: @code{(list (%current-system))})
31885 Only request builds for the given @var{systems}.
31887 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
31888 Location of the log file.
31890 @item @code{publish-port} (default: @code{5558})
31891 The TCP port of the publish server. It defaults to @code{5558}.
31893 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
31894 The list of URLs where to look for substitutes by default.
31896 @item @code{public-key}
31897 @item @code{private-key}
31898 Use the specific @var{file}s as the public/private key pair used to sign
31899 the store items being published.
31904 @subsubheading Laminar
31906 @uref{https://laminar.ohwg.net/, Laminar} is a lightweight and modular
31907 Continuous Integration service. It doesn't have a configuration web UI
31908 instead uses version-controllable configuration files and scripts.
31910 Laminar encourages the use of existing tools such as bash and cron
31911 instead of reinventing them.
31913 @defvr {Scheme Procedure} laminar-service-type
31914 The type of the Laminar service. Its value must be a
31915 @code{laminar-configuration} object, as described below.
31917 All configuration values have defaults, a minimal configuration to get
31918 Laminar running is shown below. By default, the web interface is
31919 available on port 8080.
31922 (service laminar-service-type)
31926 @deftp {Data Type} laminar-configuration
31927 Data type representing the configuration of Laminar.
31930 @item @code{laminar} (default: @code{laminar})
31931 The Laminar package to use.
31933 @item @code{home-directory} (default: @code{"/var/lib/laminar"})
31934 The directory for job configurations and run directories.
31936 @item @code{bind-http} (default: @code{"*:8080"})
31937 The interface/port or unix socket on which laminard should listen for
31938 incoming connections to the web frontend.
31940 @item @code{bind-rpc} (default: @code{"unix-abstract:laminar"})
31941 The interface/port or unix socket on which laminard should listen for
31942 incoming commands such as build triggers.
31944 @item @code{title} (default: @code{"Laminar"})
31945 The page title to show in the web frontend.
31947 @item @code{keep-rundirs} (default: @code{0})
31948 Set to an integer defining how many rundirs to keep per job. The
31949 lowest-numbered ones will be deleted. The default is 0, meaning all run
31950 dirs will be immediately deleted.
31952 @item @code{archive-url} (default: @code{#f})
31953 The web frontend served by laminard will use this URL to form links to
31954 artefacts archived jobs.
31956 @item @code{base-url} (default: @code{#f})
31957 Base URL to use for links to laminar itself.
31962 @node Power Management Services
31963 @subsection Power Management Services
31966 @cindex power management with TLP
31967 @subsubheading TLP daemon
31969 The @code{(gnu services pm)} module provides a Guix service definition
31970 for the Linux power management tool TLP.
31972 TLP enables various powersaving modes in userspace and kernel.
31973 Contrary to @code{upower-service}, it is not a passive,
31974 monitoring tool, as it will apply custom settings each time a new power
31975 source is detected. More information can be found at
31976 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
31978 @deffn {Scheme Variable} tlp-service-type
31979 The service type for the TLP tool. The default settings are optimised
31980 for battery life on most systems, but you can tweak them to your heart's
31981 content by adding a valid @code{tlp-configuration}:
31983 (service tlp-service-type
31985 (cpu-scaling-governor-on-ac (list "performance"))
31986 (sched-powersave-on-bat? #t)))
31990 Each parameter definition is preceded by its type; for example,
31991 @samp{boolean foo} indicates that the @code{foo} parameter should be
31992 specified as a boolean. Types starting with @code{maybe-} denote
31993 parameters that won't show up in TLP config file when their value is
31994 left unset, or is explicitly set to the @code{%unset-value} value.
31996 @c The following documentation was initially generated by
31997 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
31998 @c documentation is better, so we shouldn't hesitate to edit below as
31999 @c needed. However if the change you want to make to this documentation
32000 @c can be done in an automated way, it's probably easier to change
32001 @c (generate-documentation) than to make it below and have to deal with
32002 @c the churn as TLP updates.
32004 Available @code{tlp-configuration} fields are:
32006 @deftypevr {@code{tlp-configuration} parameter} package tlp
32011 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
32012 Set to true if you wish to enable TLP.
32014 Defaults to @samp{#t}.
32018 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
32019 Default mode when no power supply can be detected. Alternatives are AC
32022 Defaults to @samp{"AC"}.
32026 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
32027 Number of seconds Linux kernel has to wait after the disk goes idle,
32028 before syncing on AC.
32030 Defaults to @samp{0}.
32034 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
32035 Same as @code{disk-idle-ac} but on BAT mode.
32037 Defaults to @samp{2}.
32041 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
32042 Dirty pages flushing periodicity, expressed in seconds.
32044 Defaults to @samp{15}.
32048 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
32049 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
32051 Defaults to @samp{60}.
32055 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
32056 CPU frequency scaling governor on AC mode. With intel_pstate driver,
32057 alternatives are powersave and performance. With acpi-cpufreq driver,
32058 alternatives are ondemand, powersave, performance and conservative.
32060 Defaults to @samp{disabled}.
32064 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
32065 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
32067 Defaults to @samp{disabled}.
32071 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
32072 Set the min available frequency for the scaling governor on AC.
32074 Defaults to @samp{disabled}.
32078 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
32079 Set the max available frequency for the scaling governor on AC.
32081 Defaults to @samp{disabled}.
32085 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
32086 Set the min available frequency for the scaling governor on BAT.
32088 Defaults to @samp{disabled}.
32092 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
32093 Set the max available frequency for the scaling governor on BAT.
32095 Defaults to @samp{disabled}.
32099 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
32100 Limit the min P-state to control the power dissipation of the CPU, in AC
32101 mode. Values are stated as a percentage of the available performance.
32103 Defaults to @samp{disabled}.
32107 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
32108 Limit the max P-state to control the power dissipation of the CPU, in AC
32109 mode. Values are stated as a percentage of the available performance.
32111 Defaults to @samp{disabled}.
32115 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
32116 Same as @code{cpu-min-perf-on-ac} on BAT mode.
32118 Defaults to @samp{disabled}.
32122 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
32123 Same as @code{cpu-max-perf-on-ac} on BAT mode.
32125 Defaults to @samp{disabled}.
32129 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
32130 Enable CPU turbo boost feature on AC mode.
32132 Defaults to @samp{disabled}.
32136 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
32137 Same as @code{cpu-boost-on-ac?} on BAT mode.
32139 Defaults to @samp{disabled}.
32143 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
32144 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
32145 used under light load conditions.
32147 Defaults to @samp{#f}.
32151 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
32152 Same as @code{sched-powersave-on-ac?} but on BAT mode.
32154 Defaults to @samp{#t}.
32158 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
32159 Enable Linux kernel NMI watchdog.
32161 Defaults to @samp{#f}.
32165 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
32166 For Linux kernels with PHC patch applied, change CPU voltages. An
32167 example value would be @samp{"F:V F:V F:V F:V"}.
32169 Defaults to @samp{disabled}.
32173 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
32174 Set CPU performance versus energy saving policy on AC@. Alternatives are
32175 performance, normal, powersave.
32177 Defaults to @samp{"performance"}.
32181 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
32182 Same as @code{energy-perf-policy-ac} but on BAT mode.
32184 Defaults to @samp{"powersave"}.
32188 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
32193 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
32194 Hard disk advanced power management level.
32198 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
32199 Same as @code{disk-apm-bat} but on BAT mode.
32203 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
32204 Hard disk spin down timeout. One value has to be specified for each
32205 declared hard disk.
32207 Defaults to @samp{disabled}.
32211 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
32212 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
32214 Defaults to @samp{disabled}.
32218 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
32219 Select IO scheduler for disk devices. One value has to be specified for
32220 each declared hard disk. Example alternatives are cfq, deadline and
32223 Defaults to @samp{disabled}.
32227 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
32228 SATA aggressive link power management (ALPM) level. Alternatives are
32229 min_power, medium_power, max_performance.
32231 Defaults to @samp{"max_performance"}.
32235 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
32236 Same as @code{sata-linkpwr-ac} but on BAT mode.
32238 Defaults to @samp{"min_power"}.
32242 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
32243 Exclude specified SATA host devices for link power management.
32245 Defaults to @samp{disabled}.
32249 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
32250 Enable Runtime Power Management for AHCI controller and disks on AC
32253 Defaults to @samp{disabled}.
32257 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
32258 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
32260 Defaults to @samp{disabled}.
32264 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
32265 Seconds of inactivity before disk is suspended.
32267 Defaults to @samp{15}.
32271 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
32272 PCI Express Active State Power Management level. Alternatives are
32273 default, performance, powersave.
32275 Defaults to @samp{"performance"}.
32279 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
32280 Same as @code{pcie-aspm-ac} but on BAT mode.
32282 Defaults to @samp{"powersave"}.
32286 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer start-charge-thresh-bat0
32287 Percentage when battery 0 should begin charging. Only supported on some laptops.
32289 Defaults to @samp{disabled}.
32293 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer stop-charge-thresh-bat0
32294 Percentage when battery 0 should stop charging. Only supported on some laptops.
32296 Defaults to @samp{disabled}.
32300 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer start-charge-thresh-bat1
32301 Percentage when battery 1 should begin charging. Only supported on some laptops.
32303 Defaults to @samp{disabled}.
32307 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer stop-charge-thresh-bat1
32308 Percentage when battery 1 should stop charging. Only supported on some laptops.
32310 Defaults to @samp{disabled}.
32314 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
32315 Radeon graphics clock speed level. Alternatives are low, mid, high,
32318 Defaults to @samp{"high"}.
32322 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
32323 Same as @code{radeon-power-ac} but on BAT mode.
32325 Defaults to @samp{"low"}.
32329 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
32330 Radeon dynamic power management method (DPM). Alternatives are battery,
32333 Defaults to @samp{"performance"}.
32337 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
32338 Same as @code{radeon-dpm-state-ac} but on BAT mode.
32340 Defaults to @samp{"battery"}.
32344 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
32345 Radeon DPM performance level. Alternatives are auto, low, high.
32347 Defaults to @samp{"auto"}.
32351 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
32352 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
32354 Defaults to @samp{"auto"}.
32358 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
32359 Wifi power saving mode.
32361 Defaults to @samp{#f}.
32365 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
32366 Same as @code{wifi-power-ac?} but on BAT mode.
32368 Defaults to @samp{#t}.
32372 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
32373 Disable wake on LAN.
32375 Defaults to @samp{#t}.
32379 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
32380 Timeout duration in seconds before activating audio power saving on
32381 Intel HDA and AC97 devices. A value of 0 disables power saving.
32383 Defaults to @samp{0}.
32387 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
32388 Same as @code{sound-powersave-ac} but on BAT mode.
32390 Defaults to @samp{1}.
32394 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
32395 Disable controller in powersaving mode on Intel HDA devices.
32397 Defaults to @samp{#t}.
32401 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
32402 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
32403 powered on again by releasing (and reinserting) the eject lever or by
32404 pressing the disc eject button on newer models.
32406 Defaults to @samp{#f}.
32410 @deftypevr {@code{tlp-configuration} parameter} string bay-device
32411 Name of the optical drive device to power off.
32413 Defaults to @samp{"sr0"}.
32417 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
32418 Runtime Power Management for PCI(e) bus devices. Alternatives are on
32421 Defaults to @samp{"on"}.
32425 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
32426 Same as @code{runtime-pm-ac} but on BAT mode.
32428 Defaults to @samp{"auto"}.
32432 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
32433 Runtime Power Management for all PCI(e) bus devices, except blacklisted
32436 Defaults to @samp{#t}.
32440 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
32441 Exclude specified PCI(e) device addresses from Runtime Power Management.
32443 Defaults to @samp{disabled}.
32447 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
32448 Exclude PCI(e) devices assigned to the specified drivers from Runtime
32453 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
32454 Enable USB autosuspend feature.
32456 Defaults to @samp{#t}.
32460 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
32461 Exclude specified devices from USB autosuspend.
32463 Defaults to @samp{disabled}.
32467 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
32468 Exclude WWAN devices from USB autosuspend.
32470 Defaults to @samp{#t}.
32474 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
32475 Include specified devices into USB autosuspend, even if they are already
32476 excluded by the driver or via @code{usb-blacklist-wwan?}.
32478 Defaults to @samp{disabled}.
32482 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
32483 Enable USB autosuspend before shutdown.
32485 Defaults to @samp{disabled}.
32489 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
32490 Restore radio device state (bluetooth, wifi, wwan) from previous
32491 shutdown on system startup.
32493 Defaults to @samp{#f}.
32498 @cindex CPU frequency scaling with thermald
32499 @subsubheading Thermald daemon
32501 The @code{(gnu services pm)} module provides an interface to
32502 thermald, a CPU frequency scaling service which helps prevent overheating.
32504 @defvr {Scheme Variable} thermald-service-type
32505 This is the service type for
32506 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
32507 Thermal Daemon, which is responsible for controlling the thermal state
32508 of processors and preventing overheating.
32511 @deftp {Data Type} thermald-configuration
32512 Data type representing the configuration of @code{thermald-service-type}.
32515 @item @code{adaptive?} (default: @code{#f})
32516 Use @acronym{DPTF, Dynamic Power and Thermal Framework} adaptive tables
32519 @item @code{ignore-cpuid-check?} (default: @code{#f})
32520 Ignore cpuid check for supported CPU models.
32522 @item @code{thermald} (default: @var{thermald})
32523 Package object of thermald.
32528 @node Audio Services
32529 @subsection Audio Services
32531 The @code{(gnu services audio)} module provides a service to start MPD
32532 (the Music Player Daemon).
32535 @subsubheading Music Player Daemon
32537 The Music Player Daemon (MPD) is a service that can play music while
32538 being controlled from the local machine or over the network by a variety
32541 The following example shows how one might run @code{mpd} as user
32542 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
32545 (service mpd-service-type
32551 @defvr {Scheme Variable} mpd-service-type
32552 The service type for @command{mpd}
32555 @deftp {Data Type} mpd-configuration
32556 Data type representing the configuration of @command{mpd}.
32559 @item @code{user} (default: @code{"mpd"})
32560 The user to run mpd as.
32562 @item @code{music-dir} (default: @code{"~/Music"})
32563 The directory to scan for music files.
32565 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
32566 The directory to store playlists.
32568 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
32569 The location of the music database.
32571 @item @code{state-file} (default: @code{"~/.mpd/state"})
32572 The location of the file that stores current MPD's state.
32574 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
32575 The location of the sticker database.
32577 @item @code{port} (default: @code{"6600"})
32578 The port to run mpd on.
32580 @item @code{address} (default: @code{"any"})
32581 The address that mpd will bind to. To use a Unix domain socket,
32582 an absolute path can be specified here.
32584 @item @code{outputs} (default: @code{"(list (mpd-output))"})
32585 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
32590 @deftp {Data Type} mpd-output
32591 Data type representing an @command{mpd} audio output.
32594 @item @code{name} (default: @code{"MPD"})
32595 The name of the audio output.
32597 @item @code{type} (default: @code{"pulse"})
32598 The type of audio output.
32600 @item @code{enabled?} (default: @code{#t})
32601 Specifies whether this audio output is enabled when MPD is started. By
32602 default, all audio outputs are enabled. This is just the default
32603 setting when there is no state file; with a state file, the previous
32606 @item @code{tags?} (default: @code{#t})
32607 If set to @code{#f}, then MPD will not send tags to this output. This
32608 is only useful for output plugins that can receive tags, for example the
32609 @code{httpd} output plugin.
32611 @item @code{always-on?} (default: @code{#f})
32612 If set to @code{#t}, then MPD attempts to keep this audio output always
32613 open. This may be useful for streaming servers, when you don’t want to
32614 disconnect all listeners even when playback is accidentally stopped.
32616 @item @code{mixer-type}
32617 This field accepts a symbol that specifies which mixer should be used
32618 for this audio output: the @code{hardware} mixer, the @code{software}
32619 mixer, the @code{null} mixer (allows setting the volume, but with no
32620 effect; this can be used as a trick to implement an external mixer
32621 External Mixer) or no mixer (@code{none}).
32623 @item @code{extra-options} (default: @code{'()})
32624 An association list of option symbols to string values to be appended to
32625 the audio output configuration.
32630 The following example shows a configuration of @code{mpd} that provides
32631 an HTTP audio streaming output.
32634 (service mpd-service-type
32642 `((encoder . "vorbis")
32643 (port . "8080"))))))))
32647 @node Virtualization Services
32648 @subsection Virtualization Services
32650 The @code{(gnu services virtualization)} module provides services for
32651 the libvirt and virtlog daemons, as well as other virtualization-related
32654 @subsubheading Libvirt daemon
32656 @code{libvirtd} is the server side daemon component of the libvirt
32657 virtualization management system. This daemon runs on host servers
32658 and performs required management tasks for virtualized guests.
32660 @deffn {Scheme Variable} libvirt-service-type
32661 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
32662 Its value must be a @code{libvirt-configuration}.
32665 (service libvirt-service-type
32666 (libvirt-configuration
32667 (unix-sock-group "libvirt")
32668 (tls-port "16555")))
32672 @c Auto-generated with (generate-libvirt-documentation)
32673 Available @code{libvirt-configuration} fields are:
32675 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
32680 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
32681 Flag listening for secure TLS connections on the public TCP/IP port.
32682 You must set @code{listen} for this to have any effect.
32684 It is necessary to setup a CA and issue server certificates before using
32687 Defaults to @samp{#t}.
32691 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
32692 Listen for unencrypted TCP connections on the public TCP/IP port. You must
32693 set @code{listen} for this to have any effect.
32695 Using the TCP socket requires SASL authentication by default. Only SASL
32696 mechanisms which support data encryption are allowed. This is
32697 DIGEST_MD5 and GSSAPI (Kerberos5).
32699 Defaults to @samp{#f}.
32703 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
32704 Port for accepting secure TLS connections. This can be a port number,
32707 Defaults to @samp{"16514"}.
32711 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
32712 Port for accepting insecure TCP connections. This can be a port number,
32715 Defaults to @samp{"16509"}.
32719 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
32720 IP address or hostname used for client connections.
32722 Defaults to @samp{"0.0.0.0"}.
32726 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
32727 Flag toggling mDNS advertisement of the libvirt service.
32729 Alternatively can disable for all services on a host by stopping the
32732 Defaults to @samp{#f}.
32736 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
32737 Default mDNS advertisement name. This must be unique on the immediate
32740 Defaults to @samp{"Virtualization Host <hostname>"}.
32744 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
32745 UNIX domain socket group ownership. This can be used to allow a
32746 'trusted' set of users access to management capabilities without
32749 Defaults to @samp{"root"}.
32753 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
32754 UNIX socket permissions for the R/O socket. This is used for monitoring
32757 Defaults to @samp{"0777"}.
32761 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
32762 UNIX socket permissions for the R/W socket. Default allows only root.
32763 If PolicyKit is enabled on the socket, the default will change to allow
32764 everyone (eg, 0777)
32766 Defaults to @samp{"0770"}.
32770 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
32771 UNIX socket permissions for the admin socket. Default allows only owner
32772 (root), do not change it unless you are sure to whom you are exposing
32775 Defaults to @samp{"0777"}.
32779 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
32780 The directory in which sockets will be found/created.
32782 Defaults to @samp{"/var/run/libvirt"}.
32786 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
32787 Authentication scheme for UNIX read-only sockets. By default socket
32788 permissions allow anyone to connect
32790 Defaults to @samp{"polkit"}.
32794 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
32795 Authentication scheme for UNIX read-write sockets. By default socket
32796 permissions only allow root. If PolicyKit support was compiled into
32797 libvirt, the default will be to use 'polkit' auth.
32799 Defaults to @samp{"polkit"}.
32803 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
32804 Authentication scheme for TCP sockets. If you don't enable SASL, then
32805 all TCP traffic is cleartext. Don't do this outside of a dev/test
32808 Defaults to @samp{"sasl"}.
32812 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
32813 Authentication scheme for TLS sockets. TLS sockets already have
32814 encryption provided by the TLS layer, and limited authentication is done
32817 It is possible to make use of any SASL authentication mechanism as well,
32818 by using 'sasl' for this option
32820 Defaults to @samp{"none"}.
32824 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
32825 API access control scheme.
32827 By default an authenticated user is allowed access to all APIs. Access
32828 drivers can place restrictions on this.
32830 Defaults to @samp{()}.
32834 @deftypevr {@code{libvirt-configuration} parameter} string key-file
32835 Server key file path. If set to an empty string, then no private key is
32838 Defaults to @samp{""}.
32842 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
32843 Server key file path. If set to an empty string, then no certificate is
32846 Defaults to @samp{""}.
32850 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
32851 Server key file path. If set to an empty string, then no CA certificate
32854 Defaults to @samp{""}.
32858 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
32859 Certificate revocation list path. If set to an empty string, then no
32862 Defaults to @samp{""}.
32866 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
32867 Disable verification of our own server certificates.
32869 When libvirtd starts it performs some sanity checks against its own
32872 Defaults to @samp{#f}.
32876 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
32877 Disable verification of client certificates.
32879 Client certificate verification is the primary authentication mechanism.
32880 Any client which does not present a certificate signed by the CA will be
32883 Defaults to @samp{#f}.
32887 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
32888 Whitelist of allowed x509 Distinguished Name.
32890 Defaults to @samp{()}.
32894 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
32895 Whitelist of allowed SASL usernames. The format for username depends on
32896 the SASL authentication mechanism.
32898 Defaults to @samp{()}.
32902 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
32903 Override the compile time default TLS priority string. The default is
32904 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
32905 is desired for libvirt to deviate from the global default settings.
32907 Defaults to @samp{"NORMAL"}.
32911 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
32912 Maximum number of concurrent client connections to allow over all
32915 Defaults to @samp{5000}.
32919 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
32920 Maximum length of queue of connections waiting to be accepted by the
32921 daemon. Note, that some protocols supporting retransmission may obey
32922 this so that a later reattempt at connection succeeds.
32924 Defaults to @samp{1000}.
32928 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
32929 Maximum length of queue of accepted but not yet authenticated clients.
32930 Set this to zero to turn this feature off
32932 Defaults to @samp{20}.
32936 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
32937 Number of workers to start up initially.
32939 Defaults to @samp{5}.
32943 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
32944 Maximum number of worker threads.
32946 If the number of active clients exceeds @code{min-workers}, then more
32947 threads are spawned, up to max_workers limit. Typically you'd want
32948 max_workers to equal maximum number of clients allowed.
32950 Defaults to @samp{20}.
32954 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
32955 Number of priority workers. If all workers from above pool are stuck,
32956 some calls marked as high priority (notably domainDestroy) can be
32957 executed in this pool.
32959 Defaults to @samp{5}.
32963 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
32964 Total global limit on concurrent RPC calls.
32966 Defaults to @samp{20}.
32970 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
32971 Limit on concurrent requests from a single client connection. To avoid
32972 one client monopolizing the server this should be a small fraction of
32973 the global max_requests and max_workers parameter.
32975 Defaults to @samp{5}.
32979 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
32980 Same as @code{min-workers} but for the admin interface.
32982 Defaults to @samp{1}.
32986 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
32987 Same as @code{max-workers} but for the admin interface.
32989 Defaults to @samp{5}.
32993 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
32994 Same as @code{max-clients} but for the admin interface.
32996 Defaults to @samp{5}.
33000 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
33001 Same as @code{max-queued-clients} but for the admin interface.
33003 Defaults to @samp{5}.
33007 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
33008 Same as @code{max-client-requests} but for the admin interface.
33010 Defaults to @samp{5}.
33014 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
33015 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
33017 Defaults to @samp{3}.
33021 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
33024 A filter allows to select a different logging level for a given category
33025 of logs. The format for a filter is one of:
33036 where @code{name} is a string which is matched against the category
33037 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
33038 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
33039 name in the filter can be a substring of the full category name, in
33040 order to match multiple similar categories), the optional @samp{"+"}
33041 prefix tells libvirt to log stack trace for each message matching name,
33042 and @code{x} is the minimal level where matching messages should be
33060 Multiple filters can be defined in a single filters statement, they just
33061 need to be separated by spaces.
33063 Defaults to @samp{"3:remote 4:event"}.
33067 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
33070 An output is one of the places to save logging information. The format
33071 for an output can be:
33075 output goes to stderr
33077 @item x:syslog:name
33078 use syslog for the output and use the given name as the ident
33080 @item x:file:file_path
33081 output to a file, with the given filepath
33084 output to journald logging system
33088 In all case the x prefix is the minimal level, acting as a filter
33105 Multiple outputs can be defined, they just need to be separated by
33108 Defaults to @samp{"3:stderr"}.
33112 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
33113 Allows usage of the auditing subsystem to be altered
33117 0: disable all auditing
33120 1: enable auditing, only if enabled on host
33123 2: enable auditing, and exit if disabled on host.
33127 Defaults to @samp{1}.
33131 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
33132 Send audit messages via libvirt logging infrastructure.
33134 Defaults to @samp{#f}.
33138 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
33139 Host UUID@. UUID must not have all digits be the same.
33141 Defaults to @samp{""}.
33145 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
33146 Source to read host UUID.
33150 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
33153 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
33157 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
33160 Defaults to @samp{"smbios"}.
33164 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
33165 A keepalive message is sent to a client after @code{keepalive_interval}
33166 seconds of inactivity to check if the client is still responding. If
33167 set to -1, libvirtd will never send keepalive requests; however clients
33168 can still send them and the daemon will send responses.
33170 Defaults to @samp{5}.
33174 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
33175 Maximum number of keepalive messages that are allowed to be sent to the
33176 client without getting any response before the connection is considered
33179 In other words, the connection is automatically closed approximately
33180 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
33181 the last message received from the client. When @code{keepalive-count}
33182 is set to 0, connections will be automatically closed after
33183 @code{keepalive-interval} seconds of inactivity without sending any
33184 keepalive messages.
33186 Defaults to @samp{5}.
33190 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
33191 Same as above but for admin interface.
33193 Defaults to @samp{5}.
33197 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
33198 Same as above but for admin interface.
33200 Defaults to @samp{5}.
33204 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
33205 Timeout for Open vSwitch calls.
33207 The @code{ovs-vsctl} utility is used for the configuration and its
33208 timeout option is set by default to 5 seconds to avoid potential
33209 infinite waits blocking libvirt.
33211 Defaults to @samp{5}.
33215 @c %end of autogenerated docs
33217 @subsubheading Virtlog daemon
33218 The virtlogd service is a server side daemon component of libvirt that is
33219 used to manage logs from virtual machine consoles.
33221 This daemon is not used directly by libvirt client applications, rather it
33222 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
33223 standalone daemon, the main @code{libvirtd} daemon can be restarted without
33224 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
33225 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
33227 @deffn {Scheme Variable} virtlog-service-type
33228 This is the type of the virtlog daemon.
33229 Its value must be a @code{virtlog-configuration}.
33232 (service virtlog-service-type
33233 (virtlog-configuration
33234 (max-clients 1000)))
33238 @deftypevar {@code{libvirt} parameter} package libvirt
33242 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
33243 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
33245 Defaults to @samp{3}.
33249 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
33252 A filter allows to select a different logging level for a given category
33253 of logs The format for a filter is one of:
33264 where @code{name} is a string which is matched against the category
33265 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
33266 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
33267 be a substring of the full category name, in order to match multiple
33268 similar categories), the optional "+" prefix tells libvirt to log stack
33269 trace for each message matching name, and @code{x} is the minimal level
33270 where matching messages should be logged:
33287 Multiple filters can be defined in a single filters statement, they just
33288 need to be separated by spaces.
33290 Defaults to @samp{"3:remote 4:event"}.
33294 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
33297 An output is one of the places to save logging information The format
33298 for an output can be:
33302 output goes to stderr
33304 @item x:syslog:name
33305 use syslog for the output and use the given name as the ident
33307 @item x:file:file_path
33308 output to a file, with the given filepath
33311 output to journald logging system
33315 In all case the x prefix is the minimal level, acting as a filter
33332 Multiple outputs can be defined, they just need to be separated by
33335 Defaults to @samp{"3:stderr"}.
33339 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
33340 Maximum number of concurrent client connections to allow over all
33343 Defaults to @samp{1024}.
33347 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
33348 Maximum file size before rolling over.
33350 Defaults to @samp{2MB}
33354 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
33355 Maximum number of backup files to keep.
33357 Defaults to @samp{3}
33361 @anchor{transparent-emulation-qemu}
33362 @subsubheading Transparent Emulation with QEMU
33365 @cindex @code{binfmt_misc}
33366 @code{qemu-binfmt-service-type} provides support for transparent
33367 emulation of program binaries built for different architectures---e.g.,
33368 it allows you to transparently execute an ARMv7 program on an x86_64
33369 machine. It achieves this by combining the @uref{https://www.qemu.org,
33370 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
33371 This feature only allows you to emulate GNU/Linux on a different
33372 architecture, but see below for GNU/Hurd support.
33374 @defvr {Scheme Variable} qemu-binfmt-service-type
33375 This is the type of the QEMU/binfmt service for transparent emulation.
33376 Its value must be a @code{qemu-binfmt-configuration} object, which
33377 specifies the QEMU package to use as well as the architecture we want to
33381 (service qemu-binfmt-service-type
33382 (qemu-binfmt-configuration
33383 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
33386 In this example, we enable transparent emulation for the ARM and aarch64
33387 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
33388 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
33389 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
33392 @deftp {Data Type} qemu-binfmt-configuration
33393 This is the configuration for the @code{qemu-binfmt} service.
33396 @item @code{platforms} (default: @code{'()})
33397 The list of emulated QEMU platforms. Each item must be a @dfn{platform
33398 object} as returned by @code{lookup-qemu-platforms} (see below).
33400 For example, let's suppose you're on an x86_64 machine and you have this
33404 (service qemu-binfmt-service-type
33405 (qemu-binfmt-configuration
33406 (platforms (lookup-qemu-platforms "arm"))))
33412 guix build -s armhf-linux inkscape
33416 and it will build Inkscape for ARMv7 @emph{as if it were a native
33417 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
33418 if you'd like to test a package build for an architecture you don't have
33421 @item @code{qemu} (default: @code{qemu})
33422 The QEMU package to use.
33426 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
33427 Return the list of QEMU platform objects corresponding to
33428 @var{platforms}@dots{}. @var{platforms} must be a list of strings
33429 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
33430 @code{"mips64el"}, and so on.
33433 @deffn {Scheme Procedure} qemu-platform? @var{obj}
33434 Return true if @var{obj} is a platform object.
33437 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
33438 Return the name of @var{platform}---a string such as @code{"arm"}.
33442 @subsubheading QEMU Guest Agent
33446 The QEMU guest agent provides control over the emulated system to the
33447 host. The @code{qemu-guest-agent} service runs the agent on Guix
33448 guests. To control the agent from the host, open a socket by invoking
33449 QEMU with the following arguments:
33452 qemu-system-x86_64 \
33453 -chardev socket,path=/tmp/qga.sock,server=on,wait=off,id=qga0 \
33454 -device virtio-serial \
33455 -device virtserialport,chardev=qga0,name=org.qemu.guest_agent.0 \
33459 This creates a socket at @file{/tmp/qga.sock} on the host. Once the
33460 guest agent is running, you can issue commands with @code{socat}:
33463 $ guix shell socat -- socat unix-connect:/tmp/qga.sock stdio
33464 @{"execute": "guest-get-host-name"@}
33465 @{"return": @{"host-name": "guix"@}@}
33468 See @url{https://wiki.qemu.org/Features/GuestAgent,QEMU guest agent
33469 documentation} for more options and commands.
33471 @defvr {Scheme Variable} qemu-guest-agent-service-type
33472 Service type for the QEMU guest agent service.
33475 @deftp {Data Type} qemu-guest-agent-configuration
33476 Configuration for the @code{qemu-guest-agent} service.
33479 @item @code{qemu} (default: @code{qemu-minimal})
33480 The QEMU package to use.
33482 @item @code{device} (default: @code{""})
33483 File name of the device or socket the agent uses to communicate with the
33484 host. If empty, QEMU uses a default file name.
33489 @subsubheading The Hurd in a Virtual Machine
33491 @cindex @code{hurd}
33495 Service @code{hurd-vm} provides support for running GNU/Hurd in a
33496 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
33497 to be used on GNU/Linux and the given GNU/Hurd operating system
33498 configuration is cross-compiled. The virtual machine is a Shepherd
33499 service that can be referred to by the names @code{hurd-vm} and
33500 @code{childhurd} and be controlled with commands such as:
33504 herd stop childhurd
33507 When the service is running, you can view its console by connecting to
33508 it with a VNC client, for example with:
33511 guix shell tigervnc-client -- vncviewer localhost:5900
33514 The default configuration (see @code{hurd-vm-configuration} below)
33515 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
33516 (the virtual machine emulator) redirects to port 10222 on the host.
33517 Thus, you can connect over SSH to the childhurd with:
33520 ssh root@@localhost -p 10022
33523 The childhurd is volatile and stateless: it starts with a fresh root
33524 file system every time you restart it. By default though, all the files
33525 under @file{/etc/childhurd} on the host are copied as is to the root
33526 file system of the childhurd when it boots. This allows you to
33527 initialize ``secrets'' inside the VM: SSH host keys, authorized
33528 substitute keys, and so on---see the explanation of @code{secret-root}
33531 @defvr {Scheme Variable} hurd-vm-service-type
33532 This is the type of the Hurd in a Virtual Machine service. Its value
33533 must be a @code{hurd-vm-configuration} object, which specifies the
33534 operating system (@pxref{operating-system Reference}) and the disk size
33535 for the Hurd Virtual Machine, the QEMU package to use as well as the
33536 options for running it.
33541 (service hurd-vm-service-type
33542 (hurd-vm-configuration
33543 (disk-size (* 5000 (expt 2 20))) ;5G
33544 (memory-size 1024))) ;1024MiB
33547 would create a disk image big enough to build GNU@tie{}Hello, with some
33551 @deftp {Data Type} hurd-vm-configuration
33552 The data type representing the configuration for
33553 @code{hurd-vm-service-type}.
33556 @item @code{os} (default: @var{%hurd-vm-operating-system})
33557 The operating system to instantiate. This default is bare-bones with a
33558 permissive OpenSSH secure shell daemon listening on port 2222
33559 (@pxref{Networking Services, @code{openssh-service-type}}).
33561 @item @code{qemu} (default: @code{qemu-minimal})
33562 The QEMU package to use.
33564 @item @code{image} (default: @var{hurd-vm-disk-image})
33565 The procedure used to build the disk-image built from this
33568 @item @code{disk-size} (default: @code{'guess})
33569 The size of the disk image.
33571 @item @code{memory-size} (default: @code{512})
33572 The memory size of the Virtual Machine in mebibytes.
33574 @item @code{options} (default: @code{'("--snapshot")})
33575 The extra options for running QEMU.
33577 @item @code{id} (default: @code{#f})
33578 If set, a non-zero positive integer used to parameterize Childhurd
33579 instances. It is appended to the service's name,
33580 e.g. @code{childhurd1}.
33582 @item @code{net-options} (default: @var{hurd-vm-net-options})
33583 The procedure used to produce the list of QEMU networking options.
33585 By default, it produces
33588 '("--device" "rtl8139,netdev=net0"
33589 "--netdev" (string-append
33591 "hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004,"
33592 "hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222,"
33593 "hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900"))
33596 with forwarded ports:
33599 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
33600 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
33601 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
33604 @item @code{secret-root} (default: @file{/etc/childhurd})
33605 The root directory with out-of-band secrets to be installed into the
33606 childhurd once it runs. Childhurds are volatile which means that on
33607 every startup, secrets such as the SSH host keys and Guix signing key
33610 If the @file{/etc/childhurd} directory does not exist, the
33611 @code{secret-service} running in the Childhurd will be sent an empty
33614 By default, the service automatically populates @file{/etc/childhurd}
33615 with the following non-volatile secrets, unless they already exist:
33618 /etc/childhurd/etc/guix/acl
33619 /etc/childhurd/etc/guix/signing-key.pub
33620 /etc/childhurd/etc/guix/signing-key.sec
33621 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
33622 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
33623 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
33624 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
33627 These files are automatically sent to the guest Hurd VM when it boots,
33628 including permissions.
33630 @cindex childhurd, offloading
33631 @cindex Hurd, offloading
33632 Having these files in place means that only a couple of things are
33633 missing to allow the host to offload @code{i586-gnu} builds to the
33638 Authorizing the childhurd's key on the host so that the host accepts
33639 build results coming from the childhurd, which can be done like so:
33642 guix archive --authorize < \
33643 /etc/childhurd/etc/guix/signing-key.pub
33647 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
33651 We're working towards making that happen automatically---get in touch
33652 with us at @email{guix-devel@@gnu.org} to discuss it!
33656 Note that by default the VM image is volatile, i.e., once stopped the
33657 contents are lost. If you want a stateful image instead, override the
33658 configuration's @code{image} and @code{options} without
33659 the @code{--snapshot} flag using something along these lines:
33662 (service hurd-vm-service-type
33663 (hurd-vm-configuration
33664 (image (const "/out/of/store/writable/hurd.img"))
33668 @subsubheading Ganeti
33673 This service is considered experimental. Configuration options may be changed
33674 in a backwards-incompatible manner, and not all features have been thorougly
33675 tested. Users of this service are encouraged to share their experience at
33676 @email{guix-devel@@gnu.org}.
33679 Ganeti is a virtual machine management system. It is designed to keep virtual
33680 machines running on a cluster of servers even in the event of hardware failures,
33681 and to make maintenance and recovery tasks easy. It consists of multiple
33682 services which are described later in this section. In addition to the Ganeti
33683 service, you will need the OpenSSH service (@pxref{Networking Services,
33684 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
33685 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
33686 and address (or use a DNS server).
33688 All nodes participating in a Ganeti cluster should have the same Ganeti and
33689 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
33690 cluster node that supports multiple storage backends, and installs the
33691 @code{debootstrap} and @code{guix} @dfn{OS providers}:
33694 (use-package-modules virtualization)
33695 (use-service-modules base ganeti networking ssh)
33698 (host-name "node1")
33699 (hosts-file (plain-file "hosts" (format #f "
33700 127.0.0.1 localhost
33703 192.168.1.200 ganeti.example.com
33704 192.168.1.201 node1.example.com node1
33705 192.168.1.202 node2.example.com node2
33708 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
33709 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
33710 (packages (append (map specification->package
33711 '("qemu" "lvm2" "drbd-utils" "ceph"
33712 ;; Add the debootstrap and guix OS providers.
33713 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
33716 (append (list (service static-networking-service-type
33717 (list (static-networking
33719 (list (network-address
33721 (value "192.168.1.201/24"))))
33723 (list (network-route
33724 (destination "default")
33725 (gateway "192.168.1.254"))))
33726 (name-servers '("192.168.1.252"
33727 "192.168.1.253")))))
33729 ;; Ganeti uses SSH to communicate between nodes.
33730 (service openssh-service-type
33731 (openssh-configuration
33732 (permit-root-login 'prohibit-password)))
33734 (service ganeti-service-type
33735 (ganeti-configuration
33736 ;; This list specifies allowed file system paths
33737 ;; for storing virtual machine images.
33738 (file-storage-paths '("/srv/ganeti/file-storage"))
33739 ;; This variable configures a single "variant" for
33740 ;; both Debootstrap and Guix that works with KVM.
33741 (os %default-ganeti-os))))
33745 Users are advised to read the
33746 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
33747 administrators guide} to learn about the various cluster options and
33748 day-to-day operations. There is also a
33749 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
33750 describing how to configure and initialize a small cluster.
33752 @defvr {Scheme Variable} ganeti-service-type
33753 This is a service type that includes all the various services that Ganeti
33756 Its value is a @code{ganeti-configuration} object that defines the package
33757 to use for CLI operations, as well as configuration for the various daemons.
33758 Allowed file storage paths and available guest operating systems are also
33759 configured through this data type.
33762 @deftp {Data Type} ganeti-configuration
33763 The @code{ganeti} service takes the following configuration options:
33766 @item @code{ganeti} (default: @code{ganeti})
33767 The @code{ganeti} package to use. It will be installed to the system profile
33768 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
33769 that the value specified here does not affect the other services as each refer
33770 to a specific @code{ganeti} package (see below).
33772 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
33773 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
33774 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
33775 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
33776 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
33777 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
33778 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
33779 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
33780 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
33781 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
33783 These options control the various daemons and cron jobs that are distributed
33784 with Ganeti. The possible values for these are described in detail below.
33785 To override a setting, you must use the configuration type for that service:
33788 (service ganeti-service-type
33789 (ganeti-configuration
33790 (rapi-configuration
33791 (ganeti-rapi-configuration
33792 (interface "eth1"))))
33793 (watcher-configuration
33794 (ganeti-watcher-configuration
33795 (rapi-ip "10.0.0.1"))))
33798 @item @code{file-storage-paths} (default: @code{'()})
33799 List of allowed directories for file storage backend.
33801 @item @code{os} (default: @code{%default-ganeti-os})
33802 List of @code{<ganeti-os>} records.
33805 In essence @code{ganeti-service-type} is shorthand for declaring each service
33809 (service ganeti-noded-service-type)
33810 (service ganeti-confd-service-type)
33811 (service ganeti-wconfd-service-type)
33812 (service ganeti-luxid-service-type)
33813 (service ganeti-kvmd-service-type)
33814 (service ganeti-mond-service-type)
33815 (service ganeti-metad-service-type)
33816 (service ganeti-watcher-service-type)
33817 (service ganeti-cleaner-service-type)
33820 Plus a service extension for @code{etc-service-type} that configures the file
33821 storage backend and OS variants.
33825 @deftp {Data Type} ganeti-os
33826 This data type is suitable for passing to the @code{os} parameter of
33827 @code{ganeti-configuration}. It takes the following parameters:
33831 The name for this OS provider. It is only used to specify where the
33832 configuration ends up. Setting it to ``debootstrap'' will create
33833 @file{/etc/ganeti/instance-debootstrap}.
33835 @item @code{extension}
33836 The file extension for variants of this OS type. For example
33837 @file{.conf} or @file{.scm}.
33839 @item @code{variants} (default: @code{'()})
33840 List of @code{ganeti-os-variant} objects for this OS.
33845 @deftp {Data Type} ganeti-os-variant
33846 This is the data type for a Ganeti OS variant. It takes the following
33851 The name of this variant.
33853 @item @code{configuration}
33854 A configuration file for this variant.
33858 @defvr {Scheme Variable} %default-debootstrap-hooks
33859 This variable contains hooks to configure networking and the GRUB bootloader.
33862 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
33863 This variable contains a list of packages suitable for a fully-virtualized guest.
33866 @deftp {Data Type} debootstrap-configuration
33868 This data type creates configuration files suitable for the debootstrap OS provider.
33871 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
33872 When not @code{#f}, this must be a G-expression that specifies a directory with
33873 scripts that will run when the OS is installed. It can also be a list of
33874 @code{(name . file-like)} pairs. For example:
33877 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
33880 That will create a directory with one executable named @code{99-hello-world}
33881 and run it every time this variant is installed. If set to @code{#f}, hooks
33882 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
33883 @item @code{proxy} (default: @code{#f})
33884 Optional HTTP proxy to use.
33885 @item @code{mirror} (default: @code{#f})
33886 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
33887 The default varies depending on the distribution.
33888 @item @code{arch} (default: @code{#f})
33889 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
33890 on an AArch64 host. Default is to use the current system architecture.
33891 @item @code{suite} (default: @code{"stable"})
33892 When set, this must be a Debian distribution ``suite'' such as @code{buster}
33893 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
33894 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
33895 List of extra packages that will get installed by dpkg in addition
33896 to the minimal system.
33897 @item @code{components} (default: @code{#f})
33898 When set, must be a list of Debian repository ``components''. For example
33899 @code{'("main" "contrib")}.
33900 @item @code{generate-cache?} (default: @code{#t})
33901 Whether to automatically cache the generated debootstrap archive.
33902 @item @code{clean-cache} (default: @code{14})
33903 Discard the cache after this amount of days. Use @code{#f} to never
33905 @item @code{partition-style} (default: @code{'msdos})
33906 The type of partition to create. When set, it must be one of
33907 @code{'msdos}, @code{'none} or a string.
33908 @item @code{partition-alignment} (default: @code{2048})
33909 Alignment of the partition in sectors.
33913 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
33914 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
33915 takes two parameters: a name and a @code{debootstrap-configuration} object.
33918 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
33919 This is a helper procedure that creates a @code{ganeti-os} record. It takes
33920 a list of variants created with @code{debootstrap-variant}.
33923 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
33924 This is a helper procedure that creates a @code{ganeti-os-variant} record for
33925 use with the Guix OS provider. It takes a name and a G-expression that returns
33926 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
33927 Guix System configuration.
33930 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
33931 This is a helper procedure that creates a @code{ganeti-os} record. It
33932 takes a list of variants produced by @code{guix-variant}.
33935 @defvr {Scheme Variable} %default-debootstrap-variants
33936 This is a convenience variable to make the debootstrap provider work
33937 ``out of the box'' without users having to declare variants manually. It
33938 contains a single debootstrap variant with the default configuration:
33941 (list (debootstrap-variant
33943 (debootstrap-configuration)))
33947 @defvr {Scheme Variable} %default-guix-variants
33948 This is a convenience variable to make the Guix OS provider work without
33949 additional configuration. It creates a virtual machine that has an SSH
33950 server, a serial console, and authorizes the Ganeti hosts SSH keys.
33953 (list (guix-variant
33955 (file-append ganeti-instance-guix
33956 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
33960 Users can implement support for OS providers unbeknownst to Guix by extending
33961 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
33967 (extension ".conf")
33969 (list (ganeti-os-variant
33971 (configuration (plain-file "bar" "this is fine"))))))
33974 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
33975 to a file in the store with contents @code{this is fine}. It also creates
33976 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
33978 Obviously this may not work for all OS providers out there. If you find the
33979 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
33981 The rest of this section documents the various services that are included by
33982 @code{ganeti-service-type}.
33984 @defvr {Scheme Variable} ganeti-noded-service-type
33985 @command{ganeti-noded} is the daemon responsible for node-specific functions
33986 within the Ganeti system. The value of this service must be a
33987 @code{ganeti-noded-configuration} object.
33990 @deftp {Data Type} ganeti-noded-configuration
33991 This is the configuration for the @code{ganeti-noded} service.
33994 @item @code{ganeti} (default: @code{ganeti})
33995 The @code{ganeti} package to use for this service.
33997 @item @code{port} (default: @code{1811})
33998 The TCP port on which the node daemon listens for network requests.
34000 @item @code{address} (default: @code{"0.0.0.0"})
34001 The network address that the daemon will bind to. The default address means
34002 bind to all available addresses.
34004 @item @code{interface} (default: @code{#f})
34005 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
34006 that the daemon will bind to.
34008 @item @code{max-clients} (default: @code{20})
34009 This sets a limit on the maximum number of simultaneous client connections
34010 that the daemon will handle. Connections above this count are accepted, but
34011 no responses will be sent until enough connections have closed.
34013 @item @code{ssl?} (default: @code{#t})
34014 Whether to use SSL/TLS to encrypt network communications. The certificate
34015 is automatically provisioned by the cluster and can be rotated with
34016 @command{gnt-cluster renew-crypto}.
34018 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
34019 This can be used to provide a specific encryption key for TLS communications.
34021 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
34022 This can be used to provide a specific certificate for TLS communications.
34024 @item @code{debug?} (default: @code{#f})
34025 When true, the daemon performs additional logging for debugging purposes.
34026 Note that this will leak encryption details to the log files, use with caution.
34031 @defvr {Scheme Variable} ganeti-confd-service-type
34032 @command{ganeti-confd} answers queries related to the configuration of a
34033 Ganeti cluster. The purpose of this daemon is to have a highly available
34034 and fast way to query cluster configuration values. It is automatically
34035 active on all @dfn{master candidates}. The value of this service must be a
34036 @code{ganeti-confd-configuration} object.
34040 @deftp {Data Type} ganeti-confd-configuration
34041 This is the configuration for the @code{ganeti-confd} service.
34044 @item @code{ganeti} (default: @code{ganeti})
34045 The @code{ganeti} package to use for this service.
34047 @item @code{port} (default: @code{1814})
34048 The UDP port on which to listen for network requests.
34050 @item @code{address} (default: @code{"0.0.0.0"})
34051 Network address that the daemon will bind to.
34053 @item @code{debug?} (default: @code{#f})
34054 When true, the daemon performs additional logging for debugging purposes.
34059 @defvr {Scheme Variable} ganeti-wconfd-service-type
34060 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
34061 about the cluster configuration and is the only entity that can accept
34062 changes to it. All jobs that need to modify the configuration will do so
34063 by sending appropriate requests to this daemon. It only runs on the
34064 @dfn{master node} and will automatically disable itself on other nodes.
34066 The value of this service must be a
34067 @code{ganeti-wconfd-configuration} object.
34070 @deftp {Data Type} ganeti-wconfd-configuration
34071 This is the configuration for the @code{ganeti-wconfd} service.
34074 @item @code{ganeti} (default: @code{ganeti})
34075 The @code{ganeti} package to use for this service.
34077 @item @code{no-voting?} (default: @code{#f})
34078 The daemon will refuse to start if the majority of cluster nodes does not
34079 agree that it is running on the master node. Set to @code{#t} to start
34080 even if a quorum can not be reached (dangerous, use with caution).
34082 @item @code{debug?} (default: @code{#f})
34083 When true, the daemon performs additional logging for debugging purposes.
34088 @defvr {Scheme Variable} ganeti-luxid-service-type
34089 @command{ganeti-luxid} is a daemon used to answer queries related to the
34090 configuration and the current live state of a Ganeti cluster. Additionally,
34091 it is the authoritative daemon for the Ganeti job queue. Jobs can be
34092 submitted via this daemon and it schedules and starts them.
34094 It takes a @code{ganeti-luxid-configuration} object.
34097 @deftp {Data Type} ganeti-luxid-configuration
34098 This is the configuration for the @code{ganeti-luxid} service.
34101 @item @code{ganeti} (default: @code{ganeti})
34102 The @code{ganeti} package to use for this service.
34104 @item @code{no-voting?} (default: @code{#f})
34105 The daemon will refuse to start if it cannot verify that the majority of
34106 cluster nodes believes that it is running on the master node. Set to
34107 @code{#t} to ignore such checks and start anyway (this can be dangerous).
34109 @item @code{debug?} (default: @code{#f})
34110 When true, the daemon performs additional logging for debugging purposes.
34115 @defvr {Scheme Variable} ganeti-rapi-service-type
34116 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
34117 the master node and can be used to perform cluster actions programmatically
34118 via a JSON-based RPC protocol.
34120 Most query operations are allowed without authentication (unless
34121 @var{require-authentication?} is set), whereas write operations require
34122 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
34123 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
34124 API documentation} for more information.
34126 The value of this service must be a @code{ganeti-rapi-configuration} object.
34129 @deftp {Data Type} ganeti-rapi-configuration
34130 This is the configuration for the @code{ganeti-rapi} service.
34133 @item @code{ganeti} (default: @code{ganeti})
34134 The @code{ganeti} package to use for this service.
34136 @item @code{require-authentication?} (default: @code{#f})
34137 Whether to require authentication even for read-only operations.
34139 @item @code{port} (default: @code{5080})
34140 The TCP port on which to listen to API requests.
34142 @item @code{address} (default: @code{"0.0.0.0"})
34143 The network address that the service will bind to. By default it listens
34144 on all configured addresses.
34146 @item @code{interface} (default: @code{#f})
34147 When set, it must specify a specific network interface such as @code{eth0}
34148 that the daemon will bind to.
34150 @item @code{max-clients} (default: @code{20})
34151 The maximum number of simultaneous client requests to handle. Further
34152 connections are allowed, but no responses are sent until enough connections
34155 @item @code{ssl?} (default: @code{#t})
34156 Whether to use SSL/TLS encryption on the RAPI port.
34158 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
34159 This can be used to provide a specific encryption key for TLS communications.
34161 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
34162 This can be used to provide a specific certificate for TLS communications.
34164 @item @code{debug?} (default: @code{#f})
34165 When true, the daemon performs additional logging for debugging purposes.
34166 Note that this will leak encryption details to the log files, use with caution.
34171 @defvr {Scheme Variable} ganeti-kvmd-service-type
34172 @command{ganeti-kvmd} is responsible for determining whether a given KVM
34173 instance was shut down by an administrator or a user. Normally Ganeti will
34174 restart an instance that was not stopped through Ganeti itself. If the
34175 cluster option @code{user_shutdown} is true, this daemon monitors the
34176 @code{QMP} socket provided by QEMU and listens for shutdown events, and
34177 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
34178 it shuts down gracefully by itself.
34180 It takes a @code{ganeti-kvmd-configuration} object.
34183 @deftp {Data Type} ganeti-kvmd-configuration
34186 @item @code{ganeti} (default: @code{ganeti})
34187 The @code{ganeti} package to use for this service.
34189 @item @code{debug?} (default: @code{#f})
34190 When true, the daemon performs additional logging for debugging purposes.
34195 @defvr {Scheme Variable} ganeti-mond-service-type
34196 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
34197 functionality. It is responsible for running data collectors and publish the
34198 collected information through a HTTP interface.
34200 It takes a @code{ganeti-mond-configuration} object.
34203 @deftp {Data Type} ganeti-mond-configuration
34206 @item @code{ganeti} (default: @code{ganeti})
34207 The @code{ganeti} package to use for this service.
34209 @item @code{port} (default: @code{1815})
34210 The port on which the daemon will listen.
34212 @item @code{address} (default: @code{"0.0.0.0"})
34213 The network address that the daemon will bind to. By default it binds to all
34214 available interfaces.
34216 @item @code{debug?} (default: @code{#f})
34217 When true, the daemon performs additional logging for debugging purposes.
34222 @defvr {Scheme Variable} ganeti-metad-service-type
34223 @command{ganeti-metad} is an optional daemon that can be used to provide
34224 information about the cluster to instances or OS install scripts.
34226 It takes a @code{ganeti-metad-configuration} object.
34229 @deftp {Data Type} ganeti-metad-configuration
34232 @item @code{ganeti} (default: @code{ganeti})
34233 The @code{ganeti} package to use for this service.
34235 @item @code{port} (default: @code{80})
34236 The port on which the daemon will listen.
34238 @item @code{address} (default: @code{#f})
34239 If set, the daemon will bind to this address only. If left unset, the behavior
34240 depends on the cluster configuration.
34242 @item @code{debug?} (default: @code{#f})
34243 When true, the daemon performs additional logging for debugging purposes.
34248 @defvr {Scheme Variable} ganeti-watcher-service-type
34249 @command{ganeti-watcher} is a script designed to run periodically and ensure
34250 the health of a cluster. It will automatically restart instances that have
34251 stopped without Ganeti's consent, and repairs DRBD links in case a node has
34252 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
34253 that are not running. If the cluster parameter @code{ensure_node_health}
34254 is set, the watcher will also shutdown instances and DRBD devices if the
34255 node it is running on is declared offline by known master candidates.
34257 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
34259 The service takes a @code{ganeti-watcher-configuration} object.
34262 @deftp {Data Type} ganeti-watcher-configuration
34265 @item @code{ganeti} (default: @code{ganeti})
34266 The @code{ganeti} package to use for this service.
34268 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
34269 How often to run the script. The default is every five minutes.
34271 @item @code{rapi-ip} (default: @code{#f})
34272 This option needs to be specified only if the RAPI daemon is configured to use
34273 a particular interface or address. By default the cluster address is used.
34275 @item @code{job-age} (default: @code{(* 6 3600)})
34276 Archive cluster jobs older than this age, specified in seconds. The default
34277 is 6 hours. This keeps @command{gnt-job list} manageable.
34279 @item @code{verify-disks?} (default: @code{#t})
34280 If this is @code{#f}, the watcher will not try to repair broken DRBD links
34281 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
34284 @item @code{debug?} (default: @code{#f})
34285 When @code{#t}, the script performs additional logging for debugging purposes.
34290 @defvr {Scheme Variable} ganeti-cleaner-service-type
34291 @command{ganeti-cleaner} is a script designed to run periodically and remove
34292 old files from the cluster. This service type controls two @dfn{cron jobs}:
34293 one intended for the master node that permanently purges old cluster jobs,
34294 and one intended for every node that removes expired X509 certificates, keys,
34295 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
34296 it is safe to include even on non-master nodes as it will disable itself as
34299 It takes a @code{ganeti-cleaner-configuration} object.
34302 @deftp {Data Type} ganeti-cleaner-configuration
34305 @item @code{ganeti} (default: @code{ganeti})
34306 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
34308 @item @code{master-schedule} (default: @code{"45 1 * * *"})
34309 How often to run the master cleaning job. The default is once per day, at
34312 @item @code{node-schedule} (default: @code{"45 2 * * *"})
34313 How often to run the node cleaning job. The default is once per day, at
34319 @node Version Control Services
34320 @subsection Version Control Services
34322 The @code{(gnu services version-control)} module provides a service to
34323 allow remote access to local Git repositories. There are three options:
34324 the @code{git-daemon-service}, which provides access to repositories via
34325 the @code{git://} unsecured TCP-based protocol, extending the
34326 @code{nginx} web server to proxy some requests to
34327 @code{git-http-backend}, or providing a web interface with
34328 @code{cgit-service-type}.
34330 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
34332 Return a service that runs @command{git daemon}, a simple TCP server to
34333 expose repositories over the Git protocol for anonymous access.
34335 The optional @var{config} argument should be a
34336 @code{<git-daemon-configuration>} object, by default it allows read-only
34337 access to exported@footnote{By creating the magic file
34338 @file{git-daemon-export-ok} in the repository directory.} repositories under
34343 @deftp {Data Type} git-daemon-configuration
34344 Data type representing the configuration for @code{git-daemon-service}.
34347 @item @code{package} (default: @code{git})
34348 Package object of the Git distributed version control system.
34350 @item @code{export-all?} (default: @code{#f})
34351 Whether to allow access for all Git repositories, even if they do not
34352 have the @file{git-daemon-export-ok} file.
34354 @item @code{base-path} (default: @file{/srv/git})
34355 Whether to remap all the path requests as relative to the given path.
34356 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
34357 @samp{example.com}, then if you later try to pull
34358 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
34359 path as @file{/srv/git/hello.git}.
34361 @item @code{user-path} (default: @code{#f})
34362 Whether to allow @code{~user} notation to be used in requests. When
34363 specified with empty string, requests to
34364 @indicateurl{git://host/~alice/foo} is taken as a request to access
34365 @code{foo} repository in the home directory of user @code{alice}. If
34366 @code{(user-path "@var{path}")} is specified, the same request is taken
34367 as a request to access @file{@var{path}/foo} repository in the home
34368 directory of user @code{alice}.
34370 @item @code{listen} (default: @code{'()})
34371 Whether to listen on specific IP addresses or hostnames, defaults to
34374 @item @code{port} (default: @code{#f})
34375 Whether to listen on an alternative port, which defaults to 9418.
34377 @item @code{whitelist} (default: @code{'()})
34378 If not empty, only allow access to this list of directories.
34380 @item @code{extra-options} (default: @code{'()})
34381 Extra options will be passed to @command{git daemon}, please run
34382 @command{man git-daemon} for more information.
34387 The @code{git://} protocol lacks authentication. When you pull from a
34388 repository fetched via @code{git://}, you don't know whether the data you
34389 receive was modified or is even coming from the specified host, and your
34390 connection is subject to eavesdropping. It's better to use an authenticated
34391 and encrypted transport, such as @code{https}. Although Git allows you
34392 to serve repositories using unsophisticated file-based web servers,
34393 there is a faster protocol implemented by the @code{git-http-backend}
34394 program. This program is the back-end of a proper Git web service. It
34395 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
34396 on running the necessary @code{fcgiwrap} daemon.
34398 Guix has a separate configuration data type for serving Git repositories
34401 @deftp {Data Type} git-http-configuration
34402 Data type representing the configuration for a future
34403 @code{git-http-service-type}; can currently be used to configure Nginx
34404 through @code{git-http-nginx-location-configuration}.
34407 @item @code{package} (default: @var{git})
34408 Package object of the Git distributed version control system.
34410 @item @code{git-root} (default: @file{/srv/git})
34411 Directory containing the Git repositories to expose to the world.
34413 @item @code{export-all?} (default: @code{#f})
34414 Whether to expose access for all Git repositories in @var{git-root},
34415 even if they do not have the @file{git-daemon-export-ok} file.
34417 @item @code{uri-path} (default: @samp{/git/})
34418 Path prefix for Git access. With the default @samp{/git/} prefix, this
34419 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
34420 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
34421 with this prefix are not passed on to this Git instance.
34423 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
34424 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
34429 There is no @code{git-http-service-type}, currently; instead you can
34430 create an @code{nginx-location-configuration} from a
34431 @code{git-http-configuration} and then add that location to a web
34434 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
34435 [config=(git-http-configuration)]
34436 Compute an @code{nginx-location-configuration} that corresponds to the
34437 given Git http configuration. An example nginx service definition to
34438 serve the default @file{/srv/git} over HTTPS might be:
34441 (service nginx-service-type
34442 (nginx-configuration
34445 (nginx-server-configuration
34446 (listen '("443 ssl"))
34447 (server-name "git.my-host.org")
34449 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
34450 (ssl-certificate-key
34451 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
34454 (git-http-nginx-location-configuration
34455 (git-http-configuration (uri-path "/"))))))))))
34458 This example assumes that you are using Let's Encrypt to get your TLS
34459 certificate. @xref{Certificate Services}. The default @code{certbot}
34460 service will redirect all HTTP traffic on @code{git.my-host.org} to
34461 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
34462 system services. @xref{Web Services}.
34465 @subsubheading Cgit Service
34467 @cindex Cgit service
34468 @cindex Git, web interface
34469 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
34470 repositories written in C.
34472 The following example will configure the service with default values.
34473 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
34476 (service cgit-service-type)
34479 The @code{file-object} type designates either a file-like object
34480 (@pxref{G-Expressions, file-like objects}) or a string.
34482 @c %start of fragment
34484 Available @code{cgit-configuration} fields are:
34486 @deftypevr {@code{cgit-configuration} parameter} package package
34491 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
34492 NGINX configuration.
34496 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
34497 Specifies a command which will be invoked to format the content of about
34498 pages (both top-level and for each repository).
34500 Defaults to @samp{""}.
34504 @deftypevr {@code{cgit-configuration} parameter} string agefile
34505 Specifies a path, relative to each repository path, which can be used to
34506 specify the date and time of the youngest commit in the repository.
34508 Defaults to @samp{""}.
34512 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
34513 Specifies a command that will be invoked for authenticating repository
34516 Defaults to @samp{""}.
34520 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
34521 Flag which, when set to @samp{age}, enables date ordering in the branch
34522 ref list, and when set @samp{name} enables ordering by branch name.
34524 Defaults to @samp{"name"}.
34528 @deftypevr {@code{cgit-configuration} parameter} string cache-root
34529 Path used to store the cgit cache entries.
34531 Defaults to @samp{"/var/cache/cgit"}.
34535 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
34536 Number which specifies the time-to-live, in minutes, for the cached
34537 version of repository pages accessed with a fixed SHA1.
34539 Defaults to @samp{-1}.
34543 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
34544 Number which specifies the time-to-live, in minutes, for the cached
34545 version of repository pages accessed without a fixed SHA1.
34547 Defaults to @samp{5}.
34551 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
34552 Number which specifies the time-to-live, in minutes, for the cached
34553 version of the repository summary page.
34555 Defaults to @samp{5}.
34559 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
34560 Number which specifies the time-to-live, in minutes, for the cached
34561 version of the repository index page.
34563 Defaults to @samp{5}.
34567 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
34568 Number which specifies the time-to-live, in minutes, for the result of
34569 scanning a path for Git repositories.
34571 Defaults to @samp{15}.
34575 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
34576 Number which specifies the time-to-live, in minutes, for the cached
34577 version of the repository about page.
34579 Defaults to @samp{15}.
34583 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
34584 Number which specifies the time-to-live, in minutes, for the cached
34585 version of snapshots.
34587 Defaults to @samp{5}.
34591 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
34592 The maximum number of entries in the cgit cache. When set to @samp{0},
34593 caching is disabled.
34595 Defaults to @samp{0}.
34599 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
34600 Sort items in the repo list case sensitively.
34602 Defaults to @samp{#t}.
34606 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
34607 List of common prefixes which, when combined with a repository URL,
34608 generates valid clone URLs for the repository.
34610 Defaults to @samp{()}.
34614 @deftypevr {@code{cgit-configuration} parameter} list clone-url
34615 List of @code{clone-url} templates.
34617 Defaults to @samp{()}.
34621 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
34622 Command which will be invoked to format commit messages.
34624 Defaults to @samp{""}.
34628 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
34629 Flag which, when set to @samp{date}, enables strict date ordering in the
34630 commit log, and when set to @samp{topo} enables strict topological
34633 Defaults to @samp{"git log"}.
34637 @deftypevr {@code{cgit-configuration} parameter} file-object css
34638 URL which specifies the css document to include in all cgit pages.
34640 Defaults to @samp{"/share/cgit/cgit.css"}.
34644 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
34645 Specifies a command which will be invoked to format names and email
34646 address of committers, authors, and taggers, as represented in various
34647 places throughout the cgit interface.
34649 Defaults to @samp{""}.
34653 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
34654 Flag which, when set to @samp{#t}, will make cgit generate a HTML
34655 fragment suitable for embedding in other HTML pages.
34657 Defaults to @samp{#f}.
34661 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
34662 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
34663 commit history graph to the left of the commit messages in the
34664 repository log page.
34666 Defaults to @samp{#f}.
34670 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
34671 Flag which, when set to @samp{#t}, allows all filter settings to be
34672 overridden in repository-specific cgitrc files.
34674 Defaults to @samp{#f}.
34678 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
34679 Flag which, when set to @samp{#t}, allows users to follow a file in the
34682 Defaults to @samp{#f}.
34686 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
34687 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
34690 Defaults to @samp{#t}.
34694 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
34695 Flag which, when set to @samp{#t}, will make cgit generate extra links
34696 "summary", "commit", "tree" for each repo in the repository index.
34698 Defaults to @samp{#f}.
34702 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
34703 Flag which, when set to @samp{#t}, will make cgit display the owner of
34704 each repo in the repository index.
34706 Defaults to @samp{#t}.
34710 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
34711 Flag which, when set to @samp{#t}, will make cgit print the number of
34712 modified files for each commit on the repository log page.
34714 Defaults to @samp{#f}.
34718 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
34719 Flag which, when set to @samp{#t}, will make cgit print the number of
34720 added and removed lines for each commit on the repository log page.
34722 Defaults to @samp{#f}.
34726 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
34727 Flag which, when set to @code{#t}, will make cgit display remote
34728 branches in the summary and refs views.
34730 Defaults to @samp{#f}.
34734 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
34735 Flag which, when set to @code{1}, will make cgit use the subject of the
34736 parent commit as link text when generating links to parent commits in
34739 Defaults to @samp{#f}.
34743 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
34744 Flag which, when set to @samp{#t}, will make cgit use the subject of the
34745 parent commit as link text when generating links to parent commits in
34748 Defaults to @samp{#f}.
34752 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
34753 Flag which, when set to @samp{#t}, will make cgit generate linenumber
34754 links for plaintext blobs printed in the tree view.
34756 Defaults to @samp{#t}.
34760 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
34761 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
34762 set any repo specific settings.
34764 Defaults to @samp{#f}.
34768 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
34769 URL used as link to a shortcut icon for cgit.
34771 Defaults to @samp{"/favicon.ico"}.
34775 @deftypevr {@code{cgit-configuration} parameter} string footer
34776 The content of the file specified with this option will be included
34777 verbatim at the bottom of all pages (i.e.@: it replaces the standard
34778 "generated by..."@: message).
34780 Defaults to @samp{""}.
34784 @deftypevr {@code{cgit-configuration} parameter} string head-include
34785 The content of the file specified with this option will be included
34786 verbatim in the HTML HEAD section on all pages.
34788 Defaults to @samp{""}.
34792 @deftypevr {@code{cgit-configuration} parameter} string header
34793 The content of the file specified with this option will be included
34794 verbatim at the top of all pages.
34796 Defaults to @samp{""}.
34800 @deftypevr {@code{cgit-configuration} parameter} file-object include
34801 Name of a configfile to include before the rest of the current config-
34804 Defaults to @samp{""}.
34808 @deftypevr {@code{cgit-configuration} parameter} string index-header
34809 The content of the file specified with this option will be included
34810 verbatim above the repository index.
34812 Defaults to @samp{""}.
34816 @deftypevr {@code{cgit-configuration} parameter} string index-info
34817 The content of the file specified with this option will be included
34818 verbatim below the heading on the repository index page.
34820 Defaults to @samp{""}.
34824 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
34825 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
34826 in the servers timezone.
34828 Defaults to @samp{#f}.
34832 @deftypevr {@code{cgit-configuration} parameter} file-object logo
34833 URL which specifies the source of an image which will be used as a logo
34836 Defaults to @samp{"/share/cgit/cgit.png"}.
34840 @deftypevr {@code{cgit-configuration} parameter} string logo-link
34841 URL loaded when clicking on the cgit logo image.
34843 Defaults to @samp{""}.
34847 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
34848 Command which will be invoked to format the Owner column of the main
34851 Defaults to @samp{""}.
34855 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
34856 Number of items to display in atom feeds view.
34858 Defaults to @samp{10}.
34862 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
34863 Number of entries to list per page in "log" view.
34865 Defaults to @samp{50}.
34869 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
34870 Number of commit message characters to display in "log" view.
34872 Defaults to @samp{80}.
34876 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
34877 Specifies the number of entries to list per page on the repository index
34880 Defaults to @samp{50}.
34884 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
34885 Specifies the maximum number of repo description characters to display
34886 on the repository index page.
34888 Defaults to @samp{80}.
34892 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
34893 Specifies the maximum size of a blob to display HTML for in KBytes.
34895 Defaults to @samp{0}.
34899 @deftypevr {@code{cgit-configuration} parameter} string max-stats
34900 Maximum statistics period. Valid values are @samp{week},@samp{month},
34901 @samp{quarter} and @samp{year}.
34903 Defaults to @samp{""}.
34907 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
34908 Mimetype for the specified filename extension.
34910 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
34911 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
34912 "image/png") (svg "image/svg+xml"))}.
34916 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
34917 Specifies the file to use for automatic mimetype lookup.
34919 Defaults to @samp{""}.
34923 @deftypevr {@code{cgit-configuration} parameter} string module-link
34924 Text which will be used as the formatstring for a hyperlink when a
34925 submodule is printed in a directory listing.
34927 Defaults to @samp{""}.
34931 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
34932 If set to the value @samp{#t} caching will be disabled.
34934 Defaults to @samp{#f}.
34938 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
34939 If set to @samp{#t} showing full author email addresses will be
34942 Defaults to @samp{#f}.
34946 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
34947 Flag which, when set to @samp{#t}, will make cgit omit the standard
34948 header on all pages.
34950 Defaults to @samp{#f}.
34954 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
34955 A list of subdirectories inside of @code{repository-directory}, relative
34956 to it, that should loaded as Git repositories. An empty list means that
34957 all subdirectories will be loaded.
34959 Defaults to @samp{()}.
34963 @deftypevr {@code{cgit-configuration} parameter} file-object readme
34964 Text which will be used as default value for @code{cgit-repo-readme}.
34966 Defaults to @samp{""}.
34970 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
34971 If set to @code{#t} and @code{repository-directory} is enabled, if any
34972 repositories are found with a suffix of @code{.git}, this suffix will be
34973 removed for the URL and name.
34975 Defaults to @samp{#f}.
34979 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
34980 Maximum number of files to consider when detecting renames.
34982 Defaults to @samp{-1}.
34986 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
34987 The way in which repositories in each section are sorted.
34989 Defaults to @samp{""}.
34993 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
34994 Text used as content for the @code{robots} meta-tag.
34996 Defaults to @samp{("noindex" "nofollow")}.
35000 @deftypevr {@code{cgit-configuration} parameter} string root-desc
35001 Text printed below the heading on the repository index page.
35003 Defaults to @samp{"a fast webinterface for the git dscm"}.
35007 @deftypevr {@code{cgit-configuration} parameter} string root-readme
35008 The content of the file specified with this option will be included
35009 verbatim below the ``about'' link on the repository index page.
35011 Defaults to @samp{""}.
35015 @deftypevr {@code{cgit-configuration} parameter} string root-title
35016 Text printed as heading on the repository index page.
35018 Defaults to @samp{""}.
35022 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
35023 If set to @samp{#t} and repository-directory is enabled,
35024 repository-directory will recurse into directories whose name starts
35025 with a period. Otherwise, repository-directory will stay away from such
35026 directories, considered as ``hidden''. Note that this does not apply to
35027 the @file{.git} directory in non-bare repos.
35029 Defaults to @samp{#f}.
35033 @deftypevr {@code{cgit-configuration} parameter} list snapshots
35034 Text which specifies the default set of snapshot formats that cgit
35035 generates links for.
35037 Defaults to @samp{()}.
35041 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
35042 Name of the directory to scan for repositories (represents
35045 Defaults to @samp{"/srv/git"}.
35049 @deftypevr {@code{cgit-configuration} parameter} string section
35050 The name of the current repository section - all repositories defined
35051 after this option will inherit the current section name.
35053 Defaults to @samp{""}.
35057 @deftypevr {@code{cgit-configuration} parameter} string section-sort
35058 Flag which, when set to @samp{1}, will sort the sections on the
35059 repository listing by name.
35061 Defaults to @samp{""}.
35065 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
35066 A number which, if defined prior to repository-directory, specifies how
35067 many path elements from each repo path to use as a default section name.
35069 Defaults to @samp{0}.
35073 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
35074 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
35077 Defaults to @samp{#f}.
35081 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
35082 Specifies a command which will be invoked to format plaintext blobs in
35085 Defaults to @samp{""}.
35089 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
35090 Specifies the number of branches to display in the repository ``summary''
35093 Defaults to @samp{10}.
35097 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
35098 Specifies the number of log entries to display in the repository
35101 Defaults to @samp{10}.
35105 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
35106 Specifies the number of tags to display in the repository ``summary''
35109 Defaults to @samp{10}.
35113 @deftypevr {@code{cgit-configuration} parameter} string strict-export
35114 Filename which, if specified, needs to be present within the repository
35115 for cgit to allow access to that repository.
35117 Defaults to @samp{""}.
35121 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
35122 URL which, if specified, will be used as root for all cgit links.
35124 Defaults to @samp{"/"}.
35128 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
35129 A list of @dfn{cgit-repo} records to use with config.
35131 Defaults to @samp{()}.
35133 Available @code{repository-cgit-configuration} fields are:
35135 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
35136 A mask of snapshot formats for this repo that cgit generates links for,
35137 restricted by the global @code{snapshots} setting.
35139 Defaults to @samp{()}.
35143 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
35144 Override the default @code{source-filter}.
35146 Defaults to @samp{""}.
35150 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
35151 The relative URL used to access the repository.
35153 Defaults to @samp{""}.
35157 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
35158 Override the default @code{about-filter}.
35160 Defaults to @samp{""}.
35164 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
35165 Flag which, when set to @samp{age}, enables date ordering in the branch
35166 ref list, and when set to @samp{name} enables ordering by branch name.
35168 Defaults to @samp{""}.
35172 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
35173 A list of URLs which can be used to clone repo.
35175 Defaults to @samp{()}.
35179 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
35180 Override the default @code{commit-filter}.
35182 Defaults to @samp{""}.
35186 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
35187 Flag which, when set to @samp{date}, enables strict date ordering in the
35188 commit log, and when set to @samp{topo} enables strict topological
35191 Defaults to @samp{""}.
35195 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
35196 The name of the default branch for this repository. If no such branch
35197 exists in the repository, the first branch name (when sorted) is used as
35198 default instead. By default branch pointed to by HEAD, or ``master'' if
35199 there is no suitable HEAD.
35201 Defaults to @samp{""}.
35205 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
35206 The value to show as repository description.
35208 Defaults to @samp{""}.
35212 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
35213 The value to show as repository homepage.
35215 Defaults to @samp{""}.
35219 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
35220 Override the default @code{email-filter}.
35222 Defaults to @samp{""}.
35226 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
35227 A flag which can be used to disable the global setting
35228 @code{enable-commit-graph?}.
35230 Defaults to @samp{disabled}.
35234 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
35235 A flag which can be used to disable the global setting
35236 @code{enable-log-filecount?}.
35238 Defaults to @samp{disabled}.
35242 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
35243 A flag which can be used to disable the global setting
35244 @code{enable-log-linecount?}.
35246 Defaults to @samp{disabled}.
35250 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
35251 Flag which, when set to @code{#t}, will make cgit display remote
35252 branches in the summary and refs views.
35254 Defaults to @samp{disabled}.
35258 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
35259 A flag which can be used to override the global setting
35260 @code{enable-subject-links?}.
35262 Defaults to @samp{disabled}.
35266 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
35267 A flag which can be used to override the global setting
35268 @code{enable-html-serving?}.
35270 Defaults to @samp{disabled}.
35274 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
35275 Flag which, when set to @code{#t}, hides the repository from the
35278 Defaults to @samp{#f}.
35282 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
35283 Flag which, when set to @samp{#t}, ignores the repository.
35285 Defaults to @samp{#f}.
35289 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
35290 URL which specifies the source of an image which will be used as a logo
35291 on this repo’s pages.
35293 Defaults to @samp{""}.
35297 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
35298 URL loaded when clicking on the cgit logo image.
35300 Defaults to @samp{""}.
35304 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
35305 Override the default @code{owner-filter}.
35307 Defaults to @samp{""}.
35311 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
35312 Text which will be used as the formatstring for a hyperlink when a
35313 submodule is printed in a directory listing. The arguments for the
35314 formatstring are the path and SHA1 of the submodule commit.
35316 Defaults to @samp{""}.
35320 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
35321 Text which will be used as the formatstring for a hyperlink when a
35322 submodule with the specified subdirectory path is printed in a directory
35325 Defaults to @samp{()}.
35329 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
35330 Override the default maximum statistics period.
35332 Defaults to @samp{""}.
35336 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
35337 The value to show as repository name.
35339 Defaults to @samp{""}.
35343 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
35344 A value used to identify the owner of the repository.
35346 Defaults to @samp{""}.
35350 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
35351 An absolute path to the repository directory.
35353 Defaults to @samp{""}.
35357 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
35358 A path (relative to repo) which specifies a file to include verbatim as
35359 the ``About'' page for this repo.
35361 Defaults to @samp{""}.
35365 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
35366 The name of the current repository section - all repositories defined
35367 after this option will inherit the current section name.
35369 Defaults to @samp{""}.
35373 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
35374 Extra options will be appended to cgitrc file.
35376 Defaults to @samp{()}.
35382 @deftypevr {@code{cgit-configuration} parameter} list extra-options
35383 Extra options will be appended to cgitrc file.
35385 Defaults to @samp{()}.
35390 @c %end of fragment
35392 However, it could be that you just want to get a @code{cgitrc} up and
35393 running. In that case, you can pass an @code{opaque-cgit-configuration}
35394 as a record to @code{cgit-service-type}. As its name indicates, an
35395 opaque configuration does not have easy reflective capabilities.
35397 Available @code{opaque-cgit-configuration} fields are:
35399 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
35403 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
35404 The contents of the @code{cgitrc}, as a string.
35407 For example, if your @code{cgitrc} is just the empty string, you
35408 could instantiate a cgit service like this:
35411 (service cgit-service-type
35412 (opaque-cgit-configuration
35416 @subsubheading Gitolite Service
35418 @cindex Gitolite service
35419 @cindex Git, hosting
35420 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
35421 repositories on a central server.
35423 Gitolite can handle multiple repositories and users, and supports flexible
35424 configuration of the permissions for the users on the repositories.
35426 The following example will configure Gitolite using the default @code{git}
35427 user, and the provided SSH public key.
35430 (service gitolite-service-type
35431 (gitolite-configuration
35432 (admin-pubkey (plain-file
35434 "ssh-rsa AAAA... guix@@example.com"))))
35437 Gitolite is configured through a special admin repository which you can clone,
35438 for example, if you setup Gitolite on @code{example.com}, you would run the
35439 following command to clone the admin repository.
35442 git clone git@@example.com:gitolite-admin
35445 When the Gitolite service is activated, the provided @code{admin-pubkey} will
35446 be inserted in to the @file{keydir} directory in the gitolite-admin
35447 repository. If this results in a change in the repository, it will be
35448 committed using the message ``gitolite setup by GNU Guix''.
35450 @deftp {Data Type} gitolite-configuration
35451 Data type representing the configuration for @code{gitolite-service-type}.
35454 @item @code{package} (default: @var{gitolite})
35455 Gitolite package to use.
35457 @item @code{user} (default: @var{git})
35458 User to use for Gitolite. This will be user that you use when accessing
35461 @item @code{group} (default: @var{git})
35462 Group to use for Gitolite.
35464 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
35465 Directory in which to store the Gitolite configuration and repositories.
35467 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
35468 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
35469 representing the configuration for Gitolite.
35471 @item @code{admin-pubkey} (default: @var{#f})
35472 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
35473 setup Gitolite. This will be inserted in to the @file{keydir} directory
35474 within the gitolite-admin repository.
35476 To specify the SSH key as a string, use the @code{plain-file} function.
35479 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
35485 @deftp {Data Type} gitolite-rc-file
35486 Data type representing the Gitolite RC file.
35489 @item @code{umask} (default: @code{#o0077})
35490 This controls the permissions Gitolite sets on the repositories and their
35493 A value like @code{#o0027} will give read access to the group used by Gitolite
35494 (by default: @code{git}). This is necessary when using Gitolite with software
35495 like cgit or gitweb.
35497 @item @code{unsafe-pattern} (default: @code{#f})
35498 An optional Perl regular expression for catching unsafe configurations in
35499 the configuration file. See
35500 @uref{https://gitolite.com/gitolite/git-config.html#compensating-for-unsafe_patt,
35501 Gitolite's documentation} for more information.
35503 When the value is not @code{#f}, it should be a string containing a Perl
35504 regular expression, such as @samp{"[`~#\$\&()|;<>]"}, which is the default
35505 value used by gitolite. It rejects any special character in configuration
35506 that might be interpreted by a shell, which is useful when sharing the
35507 administration burden with other people that do not otherwise have shell
35508 access on the server.
35510 @item @code{git-config-keys} (default: @code{""})
35511 Gitolite allows you to set git config values using the @samp{config}
35512 keyword. This setting allows control over the config keys to accept.
35514 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
35515 Set the role names allowed to be used by users running the perms command.
35517 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
35518 This setting controls the commands and features to enable within Gitolite.
35524 @subsubheading Gitile Service
35526 @cindex Gitile service
35528 @uref{https://git.lepiller.eu/gitile, Gitile} is a Git forge for viewing
35529 public git repository contents from a web browser.
35531 Gitile works best in collaboration with Gitolite, and will serve the public
35532 repositories from Gitolite by default. The service should listen only on
35533 a local port, and a webserver should be configured to serve static resources.
35534 The gitile service provides an easy way to extend the Nginx service for
35535 that purpose (@pxref{NGINX}).
35537 The following example will configure Gitile to serve repositories from a
35538 custom location, with some default messages for the home page and the
35542 (service gitile-service-type
35543 (gitile-configuration
35544 (repositories "/srv/git")
35545 (base-git-url "https://myweb.site/git")
35546 (index-title "My git repositories")
35547 (intro '((p "This is all my public work!")))
35548 (footer '((p "This is the end")))
35549 (nginx-server-block
35550 (nginx-server-configuration
35552 "/etc/letsencrypt/live/myweb.site/fullchain.pem")
35553 (ssl-certificate-key
35554 "/etc/letsencrypt/live/myweb.site/privkey.pem")
35555 (listen '("443 ssl http2" "[::]:443 ssl http2"))
35558 ;; Allow for https anonymous fetch on /git/ urls.
35559 (git-http-nginx-location-configuration
35560 (git-http-configuration
35562 (git-root "/var/lib/gitolite/repositories")))))))))
35565 In addition to the configuration record, you should configure your git
35566 repositories to contain some optional information. First, your public
35567 repositories need to contain the @file{git-daemon-export-ok} magic file
35568 that allows Git to export the repository. Gitile uses the presence of this
35569 file to detect public repositories it should make accessible. To do so with
35570 Gitolite for instance, modify your @file{conf/gitolite.conf} to include
35571 this in the repositories you want to make public:
35578 In addition, Gitile can read the repository configuration to display more
35579 information on the repository. Gitile uses the gitweb namespace for its
35580 configuration. As an example, you can use the following in your
35581 @file{conf/gitolite.conf}:
35586 desc = A long description, optionally with <i>HTML</i>, shown on the index page
35587 config gitweb.name = The Foo Project
35588 config gitweb.synopsis = A short description, shown on the main page of the project
35591 Do not forget to commit and push these changes once you are satisfied. You
35592 may need to change your gitolite configuration to allow the previous
35593 configuration options to be set. One way to do that is to add the
35594 following service definition:
35597 (service gitolite-service-type
35598 (gitolite-configuration
35599 (admin-pubkey (local-file "key.pub"))
35603 ;; Allow to set any configuration key
35604 (git-config-keys ".*")
35605 ;; Allow any text as a valid configuration value
35606 (unsafe-patt "^$")))))
35609 @deftp {Data Type} gitile-configuration
35610 Data type representing the configuration for @code{gitile-service-type}.
35613 @item @code{package} (default: @var{gitile})
35614 Gitile package to use.
35616 @item @code{host} (default: @code{"localhost"})
35617 The host on which gitile is listening.
35619 @item @code{port} (default: @code{8080})
35620 The port on which gitile is listening.
35622 @item @code{database} (default: @code{"/var/lib/gitile/gitile-db.sql"})
35623 The location of the database.
35625 @item @code{repositories} (default: @code{"/var/lib/gitolite/repositories"})
35626 The location of the repositories. Note that only public repositories will
35627 be shown by Gitile. To make a repository public, add an empty
35628 @file{git-daemon-export-ok} file at the root of that repository.
35630 @item @code{base-git-url}
35631 The base git url that will be used to show clone commands.
35633 @item @code{index-title} (default: @code{"Index"})
35634 The page title for the index page that lists all the available repositories.
35636 @item @code{intro} (default: @code{'()})
35637 The intro content, as a list of sxml expressions. This is shown above the list
35638 of repositories, on the index page.
35640 @item @code{footer} (default: @code{'()})
35641 The footer content, as a list of sxml expressions. This is shown on every
35642 page served by Gitile.
35644 @item @code{nginx-server-block}
35645 An nginx server block that will be extended and used as a reverse proxy by
35646 Gitile to serve its pages, and as a normal web server to serve its assets.
35648 You can use this block to add more custom URLs to your domain, such as a
35649 @code{/git/} URL for anonymous clones, or serving any other files you would
35655 @node Game Services
35656 @subsection Game Services
35658 @subsubheading The Battle for Wesnoth Service
35660 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
35661 based tactical strategy game, with several single player campaigns, and
35662 multiplayer games (both networked and local).
35664 @defvar {Scheme Variable} wesnothd-service-type
35665 Service type for the wesnothd service. Its value must be a
35666 @code{wesnothd-configuration} object. To run wesnothd in the default
35667 configuration, instantiate it as:
35670 (service wesnothd-service-type)
35674 @deftp {Data Type} wesnothd-configuration
35675 Data type representing the configuration of @command{wesnothd}.
35678 @item @code{package} (default: @code{wesnoth-server})
35679 The wesnoth server package to use.
35681 @item @code{port} (default: @code{15000})
35682 The port to bind the server to.
35687 @node PAM Mount Service
35688 @subsection PAM Mount Service
35691 The @code{(gnu services pam-mount)} module provides a service allowing
35692 users to mount volumes when they log in. It should be able to mount any
35693 volume format supported by the system.
35695 @defvar {Scheme Variable} pam-mount-service-type
35696 Service type for PAM Mount support.
35699 @deftp {Data Type} pam-mount-configuration
35700 Data type representing the configuration of PAM Mount.
35702 It takes the following parameters:
35706 The configuration rules that will be used to generate
35707 @file{/etc/security/pam_mount.conf.xml}.
35709 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
35710 Guile Reference Manual}), and the default ones don't mount anything for
35714 `((debug (@@ (enable "0")))
35715 (mntoptions (@@ (allow ,(string-join
35716 '("nosuid" "nodev" "loop"
35717 "encryption" "fsck" "nonempty"
35718 "allow_root" "allow_other")
35720 (mntoptions (@@ (require "nosuid,nodev")))
35721 (logout (@@ (wait "0")
35725 (mkmountpoint (@@ (enable "1")
35729 Some @code{volume} elements must be added to automatically mount volumes
35730 at login. Here's an example allowing the user @code{alice} to mount her
35731 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
35732 the partition where he stores his data:
35735 (define pam-mount-rules
35736 `((debug (@@ (enable "0")))
35737 (volume (@@ (user "alice")
35740 (mountpoint "/home/alice")))
35741 (volume (@@ (user "bob")
35744 (mountpoint "/home/bob/data")
35745 (options "defaults,autodefrag,compress")))
35746 (mntoptions (@@ (allow ,(string-join
35747 '("nosuid" "nodev" "loop"
35748 "encryption" "fsck" "nonempty"
35749 "allow_root" "allow_other")
35751 (mntoptions (@@ (require "nosuid,nodev")))
35752 (logout (@@ (wait "0")
35756 (mkmountpoint (@@ (enable "1")
35757 (remove "true")))))
35759 (service pam-mount-service-type
35760 (pam-mount-configuration
35761 (rules pam-mount-rules)))
35764 The complete list of possible options can be found in the man page for
35765 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
35770 @node Guix Services
35771 @subsection Guix Services
35773 @subsubheading Guix Build Coordinator
35774 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
35775 Coordinator} aids in distributing derivation builds among machines
35776 running an @dfn{agent}. The build daemon is still used to build the
35777 derivations, but the Guix Build Coordinator manages allocating builds
35778 and working with the results.
35780 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
35781 more connected @dfn{agent} processes. The coordinator process handles
35782 clients submitting builds, and allocating builds to agents. The agent
35783 processes talk to a build daemon to actually perform the builds, then
35784 send the results back to the coordinator.
35786 There is a script to run the coordinator component of the Guix Build
35787 Coordinator, but the Guix service uses a custom Guile script instead, to
35788 provide better integration with G-expressions used in the configuration.
35790 @defvar {Scheme Variable} guix-build-coordinator-service-type
35791 Service type for the Guix Build Coordinator. Its value must be a
35792 @code{guix-build-coordinator-configuration} object.
35795 @deftp {Data Type} guix-build-coordinator-configuration
35796 Data type representing the configuration of the Guix Build Coordinator.
35799 @item @code{package} (default: @code{guix-build-coordinator})
35800 The Guix Build Coordinator package to use.
35802 @item @code{user} (default: @code{"guix-build-coordinator"})
35803 The system user to run the service as.
35805 @item @code{group} (default: @code{"guix-build-coordinator"})
35806 The system group to run the service as.
35808 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
35809 The URI to use for the database.
35811 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
35812 The URI describing how to listen to requests from agent processes.
35814 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
35815 The URI describing how to listen to requests from clients. The client
35816 API allows submitting builds and currently isn't authenticated, so take
35817 care when configuring this value.
35819 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
35820 A G-expression for the allocation strategy to be used. This is a
35821 procedure that takes the datastore as an argument and populates the
35822 allocation plan in the database.
35824 @item @code{hooks} (default: @var{'()})
35825 An association list of hooks. These provide a way to execute arbitrary
35826 code upon certain events, like a build result being processed.
35828 @item @code{parallel-hooks} (default: @var{'()})
35829 Hooks can be configured to run in parallel. This parameter is an
35830 association list of hooks to do in parallel, where the key is the symbol
35831 for the hook and the value is the number of threads to run.
35833 @item @code{guile} (default: @code{guile-3.0-latest})
35834 The Guile package with which to run the Guix Build Coordinator.
35839 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
35840 Service type for a Guix Build Coordinator agent. Its value must be a
35841 @code{guix-build-coordinator-agent-configuration} object.
35844 @deftp {Data Type} guix-build-coordinator-agent-configuration
35845 Data type representing the configuration a Guix Build Coordinator agent.
35848 @item @code{package} (default: @code{guix-build-coordinator/agent-only})
35849 The Guix Build Coordinator package to use.
35851 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
35852 The system user to run the service as.
35854 @item @code{coordinator} (default: @code{"http://localhost:8745"})
35855 The URI to use when connecting to the coordinator.
35857 @item @code{authentication}
35858 Record describing how this agent should authenticate with the
35859 coordinator. Possible record types are described below.
35861 @item @code{systems} (default: @code{#f})
35862 The systems for which this agent should fetch builds. The agent process
35863 will use the current system it's running on as the default.
35865 @item @code{max-parallel-builds} (default: @code{1})
35866 The number of builds to perform in parallel.
35868 @item @code{max-allocated-builds} (default: @code{#f})
35869 The maximum number of builds this agent can be allocated.
35871 @item @code{max-1min-load-average} (default: @code{#f})
35872 Load average value to look at when considering starting new builds, if
35873 the 1 minute load average exceeds this value, the agent will wait before
35874 starting new builds.
35876 This will be unspecified if the value is @code{#f}, and the agent will
35877 use the number of cores reported by the system as the max 1 minute load
35880 @item @code{derivation-substitute-urls} (default: @code{#f})
35881 URLs from which to attempt to fetch substitutes for derivations, if the
35882 derivations aren't already available.
35884 @item @code{non-derivation-substitute-urls} (default: @code{#f})
35885 URLs from which to attempt to fetch substitutes for build inputs, if the
35886 input store items aren't already available.
35891 @deftp {Data Type} guix-build-coordinator-agent-password-auth
35892 Data type representing an agent authenticating with a coordinator via a
35897 The UUID of the agent. This should be generated by the coordinator
35898 process, stored in the coordinator database, and used by the intended
35901 @item @code{password}
35902 The password to use when connecting to the coordinator.
35907 @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
35908 Data type representing an agent authenticating with a coordinator via a
35909 UUID and password read from a file.
35913 The UUID of the agent. This should be generated by the coordinator
35914 process, stored in the coordinator database, and used by the intended
35917 @item @code{password-file}
35918 A file containing the password to use when connecting to the
35924 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
35925 Data type representing an agent authenticating with a coordinator via a
35926 dynamic auth token and agent name.
35929 @item @code{agent-name}
35930 Name of an agent, this is used to match up to an existing entry in the
35931 database if there is one. When no existing entry is found, a new entry
35932 is automatically added.
35935 Dynamic auth token, this is created and stored in the coordinator
35936 database, and is used by the agent to authenticate.
35941 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
35942 Data type representing an agent authenticating with a coordinator via a
35943 dynamic auth token read from a file and agent name.
35946 @item @code{agent-name}
35947 Name of an agent, this is used to match up to an existing entry in the
35948 database if there is one. When no existing entry is found, a new entry
35949 is automatically added.
35951 @item @code{token-file}
35952 File containing the dynamic auth token, this is created and stored in
35953 the coordinator database, and is used by the agent to authenticate.
35958 The Guix Build Coordinator package contains a script to query an
35959 instance of the Guix Data Service for derivations to build, and then
35960 submit builds for those derivations to the coordinator. The service
35961 type below assists in running this script. This is an additional tool
35962 that may be useful when building derivations contained within an
35963 instance of the Guix Data Service.
35965 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
35966 Service type for the
35967 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
35968 value must be a @code{guix-build-coordinator-queue-builds-configuration}
35972 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
35973 Data type representing the options to the queue builds from guix data
35977 @item @code{package} (default: @code{guix-build-coordinator})
35978 The Guix Build Coordinator package to use.
35980 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
35981 The system user to run the service as.
35983 @item @code{coordinator} (default: @code{"http://localhost:8746"})
35984 The URI to use when connecting to the coordinator.
35986 @item @code{systems} (default: @code{#f})
35987 The systems for which to fetch derivations to build.
35989 @item @code{systems-and-targets} (default: @code{#f})
35990 An association list of system and target pairs for which to fetch
35991 derivations to build.
35993 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
35994 The Guix Data Service instance from which to query to find out about
35995 derivations to build.
35997 @item @code{guix-data-service-build-server-id} (default: @code{#f})
35998 The Guix Data Service build server ID corresponding to the builds being
35999 submitted. Providing this speeds up the submitting of builds as
36000 derivations that have already been submitted can be skipped before
36001 asking the coordinator to build them.
36003 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
36004 A file to record which commits have been processed, to avoid needlessly
36005 processing them again if the service is restarted.
36010 @subsubheading Guix Data Service
36011 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
36012 and provides data about GNU Guix. This includes information about
36013 packages, derivations and lint warnings.
36015 The data is stored in a PostgreSQL database, and available through a web
36018 @defvar {Scheme Variable} guix-data-service-type
36019 Service type for the Guix Data Service. Its value must be a
36020 @code{guix-data-service-configuration} object. The service optionally
36021 extends the getmail service, as the guix-commits mailing list is used to
36022 find out about changes in the Guix git repository.
36025 @deftp {Data Type} guix-data-service-configuration
36026 Data type representing the configuration of the Guix Data Service.
36029 @item @code{package} (default: @code{guix-data-service})
36030 The Guix Data Service package to use.
36032 @item @code{user} (default: @code{"guix-data-service"})
36033 The system user to run the service as.
36035 @item @code{group} (default: @code{"guix-data-service"})
36036 The system group to run the service as.
36038 @item @code{port} (default: @code{8765})
36039 The port to bind the web service to.
36041 @item @code{host} (default: @code{"127.0.0.1"})
36042 The host to bind the web service to.
36044 @item @code{getmail-idle-mailboxes} (default: @code{#f})
36045 If set, this is the list of mailboxes that the getmail service will be
36046 configured to listen to.
36048 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
36049 If set, this is the @code{getmail-retriever-configuration} object with
36050 which to configure getmail to fetch mail from the guix-commits mailing
36053 @item @code{extra-options} (default: @var{'()})
36054 Extra command line options for @code{guix-data-service}.
36056 @item @code{extra-process-jobs-options} (default: @var{'()})
36057 Extra command line options for @code{guix-data-service-process-jobs}.
36062 @subsubheading Nar Herder
36063 The @uref{https://git.cbaines.net/guix/nar-herder/about/,Nar Herder} is
36064 a utility for managing a collection of nars.
36066 @defvar {Scheme Variable} nar-herder-type
36067 Service type for the Guix Data Service. Its value must be a
36068 @code{nar-herder-configuration} object. The service optionally
36069 extends the getmail service, as the guix-commits mailing list is used to
36070 find out about changes in the Guix git repository.
36073 @deftp {Data Type} nar-herder-configuration
36074 Data type representing the configuration of the Guix Data Service.
36077 @item @code{package} (default: @code{nar-herder})
36078 The Nar Herder package to use.
36080 @item @code{user} (default: @code{"nar-herder"})
36081 The system user to run the service as.
36083 @item @code{group} (default: @code{"nar-herder"})
36084 The system group to run the service as.
36086 @item @code{port} (default: @code{8734})
36087 The port to bind the server to.
36089 @item @code{host} (default: @code{"127.0.0.1"})
36090 The host to bind the server to.
36092 @item @code{mirror} (default: @code{#f})
36093 Optional URL of the other Nar Herder instance which should be mirrored.
36094 This means that this Nar Herder instance will download it's database,
36095 and keep it up to date.
36097 @item @code{database} (default: @code{"/var/lib/nar-herder/nar_herder.db"})
36098 Location for the database. If this Nar Herder instance is mirroring
36099 another, the database will be downloaded if it doesn't exist. If this
36100 Nar Herder instance isn't mirroring another, an empty database will be
36103 @item @code{database-dump} (default: @code{"/var/lib/nar-herder/nar_herder_dump.db"})
36104 Location of the database dump. This is created and regularly updated by
36105 taking a copy of the database. This is the version of the database that
36106 is available to download.
36108 @item @code{storage} (default: @code{#f})
36109 Optional location in which to store nars.
36111 @item @code{storage-limit} (default: @code{"none"})
36112 Limit in bytes for the nars stored in the storage location. This can
36113 also be set to ``none'' so that there is no limit.
36115 When the storage location exceeds this size, nars are removed according
36116 to the nar removal criteria.
36118 @item @code{storage-nar-removal-criteria} (default: @code{'()})
36119 Criteria used to remove nars from the storage location. These are used
36120 in conjunction with the storage limit.
36122 When the storage location exceeds the storage limit size, nars will be
36123 checked against the nar removal criteria and if any of the criteria
36124 match, they will be removed. This will continue until the storage
36125 location is below the storage limit size.
36127 Each criteria is specified by a string, then an equals sign, then
36128 another string. Currently, only one criteria is supported, checking if a
36129 nar is stored on another Nar Herder instance.
36131 @item @code{ttl} (default: @code{#f})
36132 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
36133 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
36134 days, @code{1m} means 1 month, and so on.
36136 This allows the user's Guix to keep substitute information in cache for
36139 @item @code{negative-ttl} (default: @code{#f})
36140 Similarly produce @code{Cache-Control} HTTP headers to advertise the
36141 time-to-live (TTL) of @emph{negative} lookups---missing store items, for
36142 which the HTTP 404 code is returned. By default, no negative TTL is
36145 @item @code{log-level} (default: @code{'DEBUG})
36146 Log level to use, specify a log level like @code{'INFO} to stop logging
36147 individual requests.
36152 @node Linux Services
36153 @subsection Linux Services
36156 @cindex out of memory killer
36158 @cindex early out of memory daemon
36159 @subsubheading Early OOM Service
36161 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
36162 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
36163 space and provides a more responsive and configurable alternative to the
36164 in-kernel OOM killer. It is useful to prevent the system from becoming
36165 unresponsive when it runs out of memory.
36167 @deffn {Scheme Variable} earlyoom-service-type
36168 The service type for running @command{earlyoom}, the Early OOM daemon.
36169 Its value must be a @code{earlyoom-configuration} object, described
36170 below. The service can be instantiated in its default configuration
36174 (service earlyoom-service-type)
36178 @deftp {Data Type} earlyoom-configuration
36179 This is the configuration record for the @code{earlyoom-service-type}.
36182 @item @code{earlyoom} (default: @var{earlyoom})
36183 The Earlyoom package to use.
36185 @item @code{minimum-available-memory} (default: @code{10})
36186 The threshold for the minimum @emph{available} memory, in percentages.
36188 @item @code{minimum-free-swap} (default: @code{10})
36189 The threshold for the minimum free swap memory, in percentages.
36191 @item @code{prefer-regexp} (default: @code{#f})
36192 A regular expression (as a string) to match the names of the processes
36193 that should be preferably killed.
36195 @item @code{avoid-regexp} (default: @code{#f})
36196 A regular expression (as a string) to match the names of the processes
36197 that should @emph{not} be killed.
36199 @item @code{memory-report-interval} (default: @code{0})
36200 The interval in seconds at which a memory report is printed. It is
36201 disabled by default.
36203 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
36204 A boolean indicating whether the positive adjustments set in
36205 @file{/proc/*/oom_score_adj} should be ignored.
36207 @item @code{show-debug-messages?} (default: @code{#f})
36208 A boolean indicating whether debug messages should be printed. The logs
36209 are saved at @file{/var/log/earlyoom.log}.
36211 @item @code{send-notification-command} (default: @code{#f})
36212 This can be used to provide a custom command used for sending
36218 @cindex kernel module loader
36219 @subsubheading Kernel Module Loader Service
36221 The kernel module loader service allows one to load loadable kernel
36222 modules at boot. This is especially useful for modules that don't
36223 autoload and need to be manually loaded, as is the case with
36226 @deffn {Scheme Variable} kernel-module-loader-service-type
36227 The service type for loading loadable kernel modules at boot with
36228 @command{modprobe}. Its value must be a list of strings representing
36229 module names. For example loading the drivers provided by
36230 @code{ddcci-driver-linux}, in debugging mode by passing some module
36231 parameters, can be done as follow:
36234 (use-modules (gnu) (gnu services))
36235 (use-package-modules linux)
36236 (use-service-modules linux)
36238 (define ddcci-config
36239 (plain-file "ddcci.conf"
36240 "options ddcci dyndbg delay=120"))
36244 (services (cons* (service kernel-module-loader-service-type
36245 '("ddcci" "ddcci_backlight"))
36246 (simple-service 'ddcci-config etc-service-type
36247 (list `("modprobe.d/ddcci.conf"
36250 (kernel-loadable-modules (list ddcci-driver-linux)))
36255 @cindex Platform Reliability, Availability and Serviceability daemon
36256 @subsubheading Rasdaemon Service
36258 The Rasdaemon service provides a daemon which monitors platform
36259 @acronym{RAS, Reliability@comma{} Availability@comma{} and Serviceability} reports from
36260 Linux kernel trace events, logging them to syslogd.
36262 Reliability, Availability and Serviceability is a concept used on servers meant
36263 to measure their robustness.
36265 @strong{Relability} is the probability that a system will produce correct
36269 @item Generally measured as Mean Time Between Failures (MTBF), and
36270 @item Enhanced by features that help to avoid, detect and repair hardware
36274 @strong{Availability} is the probability that a system is operational at a
36278 @item Generally measured as a percentage of downtime per a period of time, and
36279 @item Often uses mechanisms to detect and correct hardware faults in runtime.
36282 @strong{Serviceability} is the simplicity and speed with which a system can be
36283 repaired or maintained:
36286 @item Generally measured on Mean Time Between Repair (MTBR).
36290 Among the monitoring measures, the most usual ones include:
36293 @item CPU – detect errors at instruction execution and at L1/L2/L3 caches;
36294 @item Memory – add error correction logic (ECC) to detect and correct errors;
36295 @item I/O – add CRC checksums for transferred data;
36296 @item Storage – RAID, journal file systems, checksums, Self-Monitoring,
36297 Analysis and Reporting Technology (SMART).
36300 By monitoring the number of occurrences of error detections, it is possible to
36301 identify if the probability of hardware errors is increasing, and, on such
36302 case, do a preventive maintenance to replace a degraded component while those
36303 errors are correctable.
36305 For detailed information about the types of error events gathered and how to
36306 make sense of them, see the kernel administrator's guide at
36307 @url{https://www.kernel.org/doc/html/latest/admin-guide/ras.html}.
36309 @defvr {Scheme Variable} rasdaemon-service-type
36310 Service type for the @command{rasdaemon} service. It accepts a
36311 @code{rasdaemon-configuration} object. Instantiating like
36314 (service rasdaemon-service-type)
36317 will load with a default configuration, which monitors all events and logs to
36321 @deftp {Data Type} rasdaemon-configuration
36322 The data type representing the configuration of @command{rasdaemon}.
36325 @item @code{record?} (default: @code{#f})
36327 A boolean indicating whether to record the events in an SQLite database. This
36328 provides a more structured access to the information contained in the log file.
36329 The database location is hard-coded to @file{/var/lib/rasdaemon/ras-mc_event.db}.
36335 @cindex compressed swap
36336 @cindex Compressed RAM-based block devices
36337 @subsubheading Zram Device Service
36339 The Zram device service provides a compressed swap device in system
36340 memory. The Linux Kernel documentation has more information about
36341 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
36344 @deffn {Scheme Variable} zram-device-service-type
36345 This service creates the zram block device, formats it as swap and
36346 enables it as a swap device. The service's value is a
36347 @code{zram-device-configuration} record.
36349 @deftp {Data Type} zram-device-configuration
36350 This is the data type representing the configuration for the zram-device
36354 @item @code{size} (default @code{"1G"})
36355 This is the amount of space you wish to provide for the zram device. It
36356 accepts a string and can be a number of bytes or use a suffix, eg.:
36357 @code{"512M"} or @code{1024000}.
36358 @item @code{compression-algorithm} (default @code{'lzo})
36359 This is the compression algorithm you wish to use. It is difficult to
36360 list all the possible compression options, but common ones supported by
36361 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
36362 @item @code{memory-limit} (default @code{0})
36363 This is the maximum amount of memory which the zram device can use.
36364 Setting it to '0' disables the limit. While it is generally expected
36365 that compression will be 2:1, it is possible that uncompressable data
36366 can be written to swap and this is a method to limit how much memory can
36367 be used. It accepts a string and can be a number of bytes or use a
36368 suffix, eg.: @code{"2G"}.
36369 @item @code{priority} (default @code{#f})
36370 This is the priority of the swap device created from the zram device.
36371 @xref{Swap Space} for a description of swap priorities. You might want
36372 to set a specific priority for the zram device, otherwise it could end
36373 up not being used much for the reasons described there.
36379 @node Hurd Services
36380 @subsection Hurd Services
36382 @defvr {Scheme Variable} hurd-console-service-type
36383 This service starts the fancy @code{VGA} console client on the Hurd.
36385 The service's value is a @code{hurd-console-configuration} record.
36388 @deftp {Data Type} hurd-console-configuration
36389 This is the data type representing the configuration for the
36390 hurd-console-service.
36393 @item @code{hurd} (default: @var{hurd})
36394 The Hurd package to use.
36398 @defvr {Scheme Variable} hurd-getty-service-type
36399 This service starts a tty using the Hurd @code{getty} program.
36401 The service's value is a @code{hurd-getty-configuration} record.
36404 @deftp {Data Type} hurd-getty-configuration
36405 This is the data type representing the configuration for the
36406 hurd-getty-service.
36409 @item @code{hurd} (default: @var{hurd})
36410 The Hurd package to use.
36413 The name of the console this Getty runs on---e.g., @code{"tty1"}.
36415 @item @code{baud-rate} (default: @code{38400})
36416 An integer specifying the baud rate of the tty.
36421 @node Miscellaneous Services
36422 @subsection Miscellaneous Services
36424 @cindex fingerprint
36425 @subsubheading Fingerprint Service
36427 The @code{(gnu services authentication)} module provides a DBus service to
36428 read and identify fingerprints via a fingerprint sensor.
36430 @defvr {Scheme Variable} fprintd-service-type
36431 The service type for @command{fprintd}, which provides the fingerprint
36432 reading capability.
36435 (service fprintd-service-type)
36440 @subsubheading System Control Service
36442 The @code{(gnu services sysctl)} provides a service to configure kernel
36443 parameters at boot.
36445 @defvr {Scheme Variable} sysctl-service-type
36446 The service type for @command{sysctl}, which modifies kernel parameters
36447 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
36451 (service sysctl-service-type
36452 (sysctl-configuration
36453 (settings '(("net.ipv4.ip_forward" . "1")))))
36456 Since @code{sysctl-service-type} is used in the default lists of
36457 services, @code{%base-services} and @code{%desktop-services}, you can
36458 use @code{modify-services} to change its configuration and add the
36459 kernel parameters that you want (@pxref{Service Reference,
36460 @code{modify-services}}).
36463 (modify-services %base-services
36464 (sysctl-service-type config =>
36465 (sysctl-configuration
36466 (settings (append '(("net.ipv4.ip_forward" . "1"))
36467 %default-sysctl-settings)))))
36472 @deftp {Data Type} sysctl-configuration
36473 The data type representing the configuration of @command{sysctl}.
36476 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
36477 The @command{sysctl} executable to use.
36479 @item @code{settings} (default: @code{%default-sysctl-settings})
36480 An association list specifies kernel parameters and their values.
36484 @defvr {Scheme Variable} %default-sysctl-settings
36485 An association list specifying the default @command{sysctl} parameters
36490 @subsubheading PC/SC Smart Card Daemon Service
36492 The @code{(gnu services security-token)} module provides the following service
36493 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
36494 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
36495 manager that coordinates communications with smart card readers, smart cards
36496 and cryptographic tokens that are connected to the system.
36498 @defvr {Scheme Variable} pcscd-service-type
36499 Service type for the @command{pcscd} service. Its value must be a
36500 @code{pcscd-configuration} object. To run pcscd in the default
36501 configuration, instantiate it as:
36504 (service pcscd-service-type)
36508 @deftp {Data Type} pcscd-configuration
36509 The data type representing the configuration of @command{pcscd}.
36512 @item @code{pcsc-lite} (default: @code{pcsc-lite})
36513 The pcsc-lite package that provides pcscd.
36514 @item @code{usb-drivers} (default: @code{(list ccid)})
36515 List of packages that provide USB drivers to pcscd. Drivers are expected to be
36516 under @file{pcsc/drivers} in the store directory of the package.
36521 @subsubheading Lirc Service
36523 The @code{(gnu services lirc)} module provides the following service.
36525 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
36526 [#:device #f] [#:driver #f] [#:config-file #f] @
36527 [#:extra-options '()]
36528 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
36529 decodes infrared signals from remote controls.
36531 Optionally, @var{device}, @var{driver} and @var{config-file}
36532 (configuration file name) may be specified. See @command{lircd} manual
36535 Finally, @var{extra-options} is a list of additional command-line options
36536 passed to @command{lircd}.
36540 @subsubheading Spice Service
36542 The @code{(gnu services spice)} module provides the following service.
36544 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
36545 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
36546 that enables sharing the clipboard with a vm and setting the guest display
36547 resolution when the graphical console window resizes.
36550 @cindex inputattach
36551 @subsubheading inputattach Service
36553 @cindex tablet input, for Xorg
36554 @cindex touchscreen input, for Xorg
36555 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
36556 use input devices such as Wacom tablets, touchscreens, or joysticks with the
36557 Xorg display server.
36559 @deffn {Scheme Variable} inputattach-service-type
36560 Type of a service that runs @command{inputattach} on a device and
36561 dispatches events from it.
36564 @deftp {Data Type} inputattach-configuration
36566 @item @code{device-type} (default: @code{"wacom"})
36567 The type of device to connect to. Run @command{inputattach --help}, from the
36568 @code{inputattach} package, to see the list of supported device types.
36570 @item @code{device} (default: @code{"/dev/ttyS0"})
36571 The device file to connect to the device.
36573 @item @code{baud-rate} (default: @code{#f})
36574 Baud rate to use for the serial connection.
36575 Should be a number or @code{#f}.
36577 @item @code{log-file} (default: @code{#f})
36578 If true, this must be the name of a file to log messages to.
36582 @subsubheading Dictionary Service
36584 The @code{(gnu services dict)} module provides the following service:
36586 @defvr {Scheme Variable} dicod-service-type
36587 This is the type of the service that runs the @command{dicod} daemon, an
36588 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
36591 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
36592 Return a service that runs the @command{dicod} daemon, an implementation
36593 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
36595 The optional @var{config} argument specifies the configuration for
36596 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
36597 default it serves the GNU Collaborative International Dictionary of English.
36599 You can add @command{open localhost} to your @file{~/.dico} file to make
36600 @code{localhost} the default server for @command{dico} client
36601 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
36604 @deftp {Data Type} dicod-configuration
36605 Data type representing the configuration of dicod.
36608 @item @code{dico} (default: @var{dico})
36609 Package object of the GNU Dico dictionary server.
36611 @item @code{interfaces} (default: @var{'("localhost")})
36612 This is the list of IP addresses and ports and possibly socket file
36613 names to listen to (@pxref{Server Settings, @code{listen} directive,,
36614 dico, GNU Dico Manual}).
36616 @item @code{handlers} (default: @var{'()})
36617 List of @code{<dicod-handler>} objects denoting handlers (module instances).
36619 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
36620 List of @code{<dicod-database>} objects denoting dictionaries to be served.
36624 @deftp {Data Type} dicod-handler
36625 Data type representing a dictionary handler (module instance).
36629 Name of the handler (module instance).
36631 @item @code{module} (default: @var{#f})
36632 Name of the dicod module of the handler (instance). If it is @code{#f},
36633 the module has the same name as the handler.
36634 (@pxref{Modules,,, dico, GNU Dico Manual}).
36636 @item @code{options}
36637 List of strings or gexps representing the arguments for the module handler
36641 @deftp {Data Type} dicod-database
36642 Data type representing a dictionary database.
36646 Name of the database, will be used in DICT commands.
36648 @item @code{handler}
36649 Name of the dicod handler (module instance) used by this database
36650 (@pxref{Handlers,,, dico, GNU Dico Manual}).
36652 @item @code{complex?} (default: @var{#f})
36653 Whether the database configuration complex. The complex configuration
36654 will need a corresponding @code{<dicod-handler>} object, otherwise not.
36656 @item @code{options}
36657 List of strings or gexps representing the arguments for the database
36658 (@pxref{Databases,,, dico, GNU Dico Manual}).
36662 @defvr {Scheme Variable} %dicod-database:gcide
36663 A @code{<dicod-database>} object serving the GNU Collaborative International
36664 Dictionary of English using the @code{gcide} package.
36667 The following is an example @code{dicod-service} configuration.
36670 (dicod-service #:config
36671 (dicod-configuration
36672 (handlers (list (dicod-handler
36676 (list #~(string-append "dbdir=" #$wordnet))))))
36677 (databases (list (dicod-database
36680 (handler "wordnet")
36681 (options '("database=wn")))
36682 %dicod-database:gcide))))
36686 @subsubheading Docker Service
36688 The @code{(gnu services docker)} module provides the following services.
36690 @defvr {Scheme Variable} docker-service-type
36692 This is the type of the service that runs @url{https://www.docker.com,Docker},
36693 a daemon that can execute application bundles (sometimes referred to as
36694 ``containers'') in isolated environments.
36698 @deftp {Data Type} docker-configuration
36699 This is the data type representing the configuration of Docker and Containerd.
36703 @item @code{docker} (default: @code{docker})
36704 The Docker daemon package to use.
36706 @item @code{docker-cli} (default: @code{docker-cli})
36707 The Docker client package to use.
36709 @item @code{containerd} (default: @var{containerd})
36710 The Containerd package to use.
36712 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
36713 The Docker user-land networking proxy package to use.
36715 @item @code{enable-proxy?} (default @code{#t})
36716 Enable or disable the use of the Docker user-land networking proxy.
36718 @item @code{debug?} (default @code{#f})
36719 Enable or disable debug output.
36721 @item @code{enable-iptables?} (default @code{#t})
36722 Enable or disable the addition of iptables rules.
36724 @item @code{environment-variables} (default: @code{()})
36725 List of environment variables to set for @command{dockerd}.
36727 This must be a list of strings where each string has the form
36728 @samp{@var{key}=@var{value}} as in this example:
36731 (list "LANGUAGE=eo:ca:eu"
36732 "TMPDIR=/tmp/dockerd")
36738 @cindex Singularity, container service
36739 @defvr {Scheme Variable} singularity-service-type
36740 This is the type of the service that allows you to run
36741 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
36742 create and run application bundles (aka. ``containers''). The value for this
36743 service is the Singularity package to use.
36745 The service does not install a daemon; instead, it installs helper programs as
36746 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
36747 @command{singularity run} and similar commands.
36751 @subsubheading Auditd Service
36753 The @code{(gnu services auditd)} module provides the following service.
36755 @defvr {Scheme Variable} auditd-service-type
36757 This is the type of the service that runs
36758 @url{https://people.redhat.com/sgrubb/audit/,auditd},
36759 a daemon that tracks security-relevant information on your system.
36761 Examples of things that can be tracked:
36771 Failed login attempts
36778 @command{auditctl} from the @code{audit} package can be used in order
36779 to add or remove events to be tracked (until the next reboot).
36780 In order to permanently track events, put the command line arguments
36781 of auditctl into a file called @code{audit.rules} in the configuration
36782 directory (see below).
36783 @command{aureport} from the @code{audit} package can be used in order
36784 to view a report of all recorded events.
36785 The audit daemon by default logs into the file
36786 @file{/var/log/audit.log}.
36790 @deftp {Data Type} auditd-configuration
36791 This is the data type representing the configuration of auditd.
36795 @item @code{audit} (default: @code{audit})
36796 The audit package to use.
36798 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
36799 The directory containing the configuration file for the audit package, which
36800 must be named @code{auditd.conf}, and optionally some audit rules to
36801 instantiate on startup.
36807 @subsubheading R-Shiny service
36809 The @code{(gnu services science)} module provides the following service.
36811 @defvr {Scheme Variable} rshiny-service-type
36813 This is a type of service which is used to run a webapp created with
36814 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
36815 variable and runs the provided script to call @code{runApp}.
36817 @deftp {Data Type} rshiny-configuration
36818 This is the data type representing the configuration of rshiny.
36822 @item @code{package} (default: @code{r-shiny})
36823 The package to use.
36825 @item @code{binary} (default @code{"rshiny"})
36826 The name of the binary or shell script located at @code{package/bin/} to
36827 run when the service is run.
36829 The common way to create this file is as follows:
36833 (let* ((out (assoc-ref %outputs "out"))
36834 (targetdir (string-append out "/share/" ,name))
36835 (app (string-append out "/bin/" ,name))
36836 (Rbin (search-input-file %build-inputs "/bin/Rscript")))
36838 (mkdir-p (string-append out "/bin"))
36839 (call-with-output-file app
36845 runApp(launch.browser=0, port=4202)~%\n"
36854 @subsubheading Nix service
36856 The @code{(gnu services nix)} module provides the following service.
36858 @defvr {Scheme Variable} nix-service-type
36860 This is the type of the service that runs build daemon of the
36861 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
36865 (use-modules (gnu))
36866 (use-service-modules nix)
36867 (use-package-modules package-management)
36871 (packages (append (list nix)
36874 (services (append (list (service nix-service-type))
36878 After @command{guix system reconfigure} configure Nix for your user:
36881 @item Add a Nix channel and update it. See
36882 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
36884 @item Create a symlink to your profile and activate Nix profile:
36888 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
36889 $ source /run/current-system/profile/etc/profile.d/nix.sh
36894 @deftp {Data Type} nix-configuration
36895 This data type represents the configuration of the Nix daemon.
36898 @item @code{nix} (default: @code{nix})
36899 The Nix package to use.
36901 @item @code{sandbox} (default: @code{#t})
36902 Specifies whether builds are sandboxed by default.
36904 @item @code{build-sandbox-items} (default: @code{'()})
36905 This is a list of strings or objects appended to the
36906 @code{build-sandbox-items} field of the configuration file.
36908 @item @code{extra-config} (default: @code{'()})
36909 This is a list of strings or objects appended to the configuration file.
36910 It is used to pass extra text to be added verbatim to the configuration
36913 @item @code{extra-options} (default: @code{'()})
36914 Extra command line options for @code{nix-service-type}.
36919 @subsubheading Fail2Ban service
36921 @uref{http://www.fail2ban.org/, @code{fail2ban}} scans log files
36922 (e.g. @code{/var/log/apache/error_log}) and bans IP addresses that show
36923 malicious signs -- repeated password failures, attempts to make use of
36926 @code{fail2ban-service-type} service type is provided by the @code{(gnu
36927 services security)} module.
36929 This service type runs the @code{fail2ban} daemon. It can be configured
36930 in various ways, which are:
36933 @item Basic configuration
36934 The basic parameters of the Fail2Ban service can be configured via its
36935 @code{fail2ban} configuration, which is documented below.
36937 @item User-specified jail extensions
36938 The @code{fail2ban-jail-service} function can be used to add new
36941 @item Shepherd extension mechanism
36942 Service developers can extend the @code{fail2ban-service-type} service
36943 type itself via the usual service extension mechanism.
36946 @defvr {Scheme Variable} fail2ban-service-type
36948 This is the type of the service that runs @code{fail2ban} daemon. Below
36949 is an example of a basic, explicit configuration:
36954 (service fail2ban-service-type
36955 (fail2ban-configuration
36958 (fail2ban-jail-configuration
36961 ;; There is no implicit dependency on an actual SSH
36962 ;; service, so you need to provide one.
36963 (service openssh-service-type))
36968 @deffn {Scheme Procedure} fail2ban-jail-service @var{svc-type} @var{jail}
36969 Extend @var{svc-type}, a @code{<service-type>} object with @var{jail}, a
36970 @code{fail2ban-jail-configuration} object.
36978 ;; The 'fail2ban-jail-service' procedure can extend any service type
36979 ;; with a fail2ban jail. This removes the requirement to explicitly
36980 ;; extend services with fail2ban-service-type.
36981 (fail2ban-jail-service
36982 openssh-service-type
36983 (fail2ban-jail-configuration
36986 (openssh-configuration ...))))
36990 Below is the reference for the different @code{jail-service-type}
36991 configuration records.
36993 @c The documentation is to be auto-generated via
36994 @c 'generate-documentation'. See at the bottom of (gnu services
36997 @deftp {Data Type} fail2ban-configuration
36998 Available @code{fail2ban-configuration} fields are:
37001 @item @code{fail2ban} (default: @code{fail2ban}) (type: package)
37002 The @code{fail2ban} package to use. It is used for both binaries and as
37003 base default configuration that is to be extended with
37004 @code{<fail2ban-jail-configuration>} objects.
37006 @item @code{run-directory} (default: @code{"/var/run/fail2ban"}) (type: string)
37007 The state directory for the @code{fail2ban} daemon.
37009 @item @code{jails} (default: @code{()}) (type: list-of-fail2ban-jail-configurations)
37010 Instances of @code{<fail2ban-jail-configuration>} collected from
37013 @item @code{extra-jails} (default: @code{()}) (type: list-of-fail2ban-jail-configurations)
37014 Instances of @code{<fail2ban-jail-configuration>} explicitly provided.
37016 @item @code{extra-content} (default: @code{()}) (type: text-config)
37017 Extra raw content to add to the end of the @file{jail.local} file,
37018 provided as a list of file-like objects.
37024 @deftp {Data Type} fail2ban-ignore-cache-configuration
37025 Available @code{fail2ban-ignore-cache-configuration} fields are:
37028 @item @code{key} (type: string)
37031 @item @code{max-count} (type: integer)
37034 @item @code{max-time} (type: integer)
37041 @deftp {Data Type} fail2ban-jail-action-configuration
37042 Available @code{fail2ban-jail-action-configuration} fields are:
37045 @item @code{name} (type: string)
37048 @item @code{arguments} (default: @code{()}) (type: list-of-arguments)
37055 @deftp {Data Type} fail2ban-jail-configuration
37056 Available @code{fail2ban-jail-configuration} fields are:
37059 @item @code{name} (type: string)
37060 Required name of this jail configuration.
37062 @item @code{enabled?} (default: @code{#t}) (type: boolean)
37063 Whether this jail is enabled.
37065 @item @code{backend} (type: maybe-symbol)
37066 Backend to use to detect changes in the @code{log-path}. The default is
37067 'auto. To consult the defaults of the jail configuration, refer to the
37068 @file{/etc/fail2ban/jail.conf} file of the @code{fail2ban} package.
37070 @item @code{max-retry} (type: maybe-integer)
37071 The number of failures before a host get banned (e.g. @code{(max-retry
37074 @item @code{max-matches} (type: maybe-integer)
37075 The number of matches stored in ticket (resolvable via tag
37076 @code{<matches>}) in action.
37078 @item @code{find-time} (type: maybe-string)
37079 The time window during which the maximum retry count must be reached for
37080 an IP address to be banned. A host is banned if it has generated
37081 @code{max-retry} during the last @code{find-time} seconds (e.g.
37082 @code{(find-time "10m")}). It can be provided in seconds or using
37083 Fail2Ban's "time abbreviation format", as described in @command{man 5
37086 @item @code{ban-time} (type: maybe-string)
37087 The duration, in seconds or time abbreviated format, that a ban should
37088 last. (e.g. @code{(ban-time "10m")}).
37090 @item @code{ban-time-increment?} (type: maybe-boolean)
37091 Whether to consider past bans to compute increases to the default ban
37092 time of a specific IP address.
37094 @item @code{ban-time-factor} (type: maybe-string)
37095 The coefficient to use to compute an exponentially growing ban time.
37097 @item @code{ban-time-formula} (type: maybe-string)
37098 This is the formula used to calculate the next value of a ban time.
37100 @item @code{ban-time-multipliers} (type: maybe-string)
37101 Used to calculate next value of ban time instead of formula.
37103 @item @code{ban-time-max-time} (type: maybe-string)
37104 The maximum number of seconds a ban should last.
37106 @item @code{ban-time-rnd-time} (type: maybe-string)
37107 The maximum number of seconds a randomized ban time should last. This
37108 can be useful to stop ``clever'' botnets calculating the exact time an
37109 IP address can be unbanned again.
37111 @item @code{ban-time-overall-jails?} (type: maybe-boolean)
37112 When true, it specifies the search of an IP address in the database
37113 should be made across all jails. Otherwise, only the current jail of
37114 the ban IP address is considered.
37116 @item @code{ignore-self?} (type: maybe-boolean)
37117 Never ban the local machine's own IP address.
37119 @item @code{ignore-ip} (default: @code{()}) (type: list-of-strings)
37120 A list of IP addresses, CIDR masks or DNS hosts to ignore.
37121 @code{fail2ban} will not ban a host which matches an address in this
37124 @item @code{ignore-cache} (type: maybe-fail2ban-ignore-cache-configuration)
37125 Provide cache parameters for the ignore failure check.
37127 @item @code{filter} (type: maybe-fail2ban-jail-filter-configuration)
37128 The filter to use by the jail, specified via a
37129 @code{<fail2ban-jail-filter-configuration>} object. By default, jails
37130 have names matching their filter name.
37132 @item @code{log-time-zone} (type: maybe-string)
37133 The default time zone for log lines that do not have one.
37135 @item @code{log-encoding} (type: maybe-symbol)
37136 The encoding of the log files handled by the jail. Possible values are:
37137 @code{'ascii}, @code{'utf-8} and @code{'auto}.
37139 @item @code{log-path} (default: @code{()}) (type: list-of-strings)
37140 The file names of the log files to be monitored.
37142 @item @code{action} (default: @code{()}) (type: list-of-fail2ban-jail-actions)
37143 A list of @code{<fail2ban-jail-action-configuration>}.
37145 @item @code{extra-content} (default: @code{()}) (type: text-config)
37146 Extra content for the jail configuration, provided as a list of file-like
37153 @deftp {Data Type} fail2ban-jail-filter-configuration
37154 Available @code{fail2ban-jail-filter-configuration} fields are:
37157 @item @code{name} (type: string)
37160 @item @code{mode} (type: maybe-string)
37167 @c End of auto-generated fail2ban documentation.
37169 @node Setuid Programs
37170 @section Setuid Programs
37172 @cindex setuid programs
37173 @cindex setgid programs
37174 Some programs need to run with elevated privileges, even when they are
37175 launched by unprivileged users. A notorious example is the
37176 @command{passwd} program, which users can run to change their
37177 password, and which needs to access the @file{/etc/passwd} and
37178 @file{/etc/shadow} files---something normally restricted to root, for
37179 obvious security reasons. To address that, @command{passwd} should be
37180 @dfn{setuid-root}, meaning that it always runs with root privileges
37181 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
37182 for more info about the setuid mechanism).
37184 The store itself @emph{cannot} contain setuid programs: that would be a
37185 security issue since any user on the system can write derivations that
37186 populate the store (@pxref{The Store}). Thus, a different mechanism is
37187 used: instead of changing the setuid or setgid bits directly on files that
37188 are in the store, we let the system administrator @emph{declare} which
37189 programs should be entrusted with these additional privileges.
37191 The @code{setuid-programs} field of an @code{operating-system}
37192 declaration contains a list of @code{<setuid-program>} denoting the
37193 names of programs to have a setuid or setgid bit set (@pxref{Using the
37194 Configuration System}). For instance, the @command{mount.nfs} program,
37195 which is part of the nfs-utils package, with a setuid root can be
37196 designated like this:
37200 (program (file-append nfs-utils "/sbin/mount.nfs")))
37203 And then, to make @command{mount.nfs} setuid on your system, add the
37204 previous example to your operating system declaration by appending it to
37205 @code{%setuid-programs} like this:
37209 ;; Some fields omitted...
37211 (append (list (setuid-program
37212 (program (file-append nfs-utils "/sbin/mount.nfs"))))
37213 %setuid-programs)))
37216 @deftp {Data Type} setuid-program
37217 This data type represents a program with a setuid or setgid bit set.
37220 @item @code{program}
37221 A file-like object having its setuid and/or setgid bit set.
37223 @item @code{setuid?} (default: @code{#t})
37224 Whether to set user setuid bit.
37226 @item @code{setgid?} (default: @code{#f})
37227 Whether to set group setgid bit.
37229 @item @code{user} (default: @code{0})
37230 UID (integer) or user name (string) for the user owner of the program,
37233 @item @code{group} (default: @code{0})
37234 GID (integer) goup name (string) for the group owner of the program,
37240 A default set of setuid programs is defined by the
37241 @code{%setuid-programs} variable of the @code{(gnu system)} module.
37243 @defvr {Scheme Variable} %setuid-programs
37244 A list of @code{<setuid-program>} denoting common programs that are
37247 The list includes commands such as @command{passwd}, @command{ping},
37248 @command{su}, and @command{sudo}.
37251 Under the hood, the actual setuid programs are created in the
37252 @file{/run/setuid-programs} directory at system activation time. The
37253 files in this directory refer to the ``real'' binaries, which are in the
37256 @node X.509 Certificates
37257 @section X.509 Certificates
37259 @cindex HTTPS, certificates
37260 @cindex X.509 certificates
37262 Web servers available over HTTPS (that is, HTTP over the transport-layer
37263 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
37264 that the client can then use to @emph{authenticate} the server. To do
37265 that, clients verify that the server's certificate is signed by a
37266 so-called @dfn{certificate authority} (CA). But to verify the CA's
37267 signature, clients must have first acquired the CA's certificate.
37269 Web browsers such as GNU@tie{}IceCat include their own set of CA
37270 certificates, such that they are able to verify CA signatures
37273 However, most other programs that can talk HTTPS---@command{wget},
37274 @command{git}, @command{w3m}, etc.---need to be told where CA
37275 certificates can be found.
37277 @cindex @code{nss-certs}
37278 In Guix, this is done by adding a package that provides certificates
37279 to the @code{packages} field of the @code{operating-system} declaration
37280 (@pxref{operating-system Reference}). Guix includes one such package,
37281 @code{nss-certs}, which is a set of CA certificates provided as part of
37282 Mozilla's Network Security Services.
37284 Note that it is @emph{not} part of @code{%base-packages}, so you need to
37285 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
37286 most applications and libraries look for certificates by default, points
37287 to the certificates installed globally.
37289 Unprivileged users, including users of Guix on a foreign distro,
37290 can also install their own certificate package in
37291 their profile. A number of environment variables need to be defined so
37292 that applications and libraries know where to find them. Namely, the
37293 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
37294 variables. Some applications add their own environment variables; for
37295 instance, the Git version control system honors the certificate bundle
37296 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
37297 would typically run something like:
37300 guix install nss-certs
37301 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
37302 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
37303 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
37306 As another example, R requires the @env{CURL_CA_BUNDLE} environment
37307 variable to point to a certificate bundle, so you would have to run
37308 something like this:
37311 guix install nss-certs
37312 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
37315 For other applications you may want to look up the required environment
37316 variable in the relevant documentation.
37319 @node Name Service Switch
37320 @section Name Service Switch
37322 @cindex name service switch
37324 The @code{(gnu system nss)} module provides bindings to the
37325 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
37326 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
37327 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
37328 extended with new ``name'' lookup methods for system databases, which
37329 includes host names, service names, user accounts, and more (@pxref{Name
37330 Service Switch, System Databases and Name Service Switch,, libc, The GNU
37331 C Library Reference Manual}).
37333 The NSS configuration specifies, for each system database, which lookup
37334 method is to be used, and how the various methods are chained
37335 together---for instance, under which circumstances NSS should try the
37336 next method in the list. The NSS configuration is given in the
37337 @code{name-service-switch} field of @code{operating-system} declarations
37338 (@pxref{operating-system Reference, @code{name-service-switch}}).
37341 @cindex .local, host name lookup
37342 As an example, the declaration below configures the NSS to use the
37343 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
37344 back-end}, which supports host name lookups over multicast DNS (mDNS)
37345 for host names ending in @code{.local}:
37348 (name-service-switch
37349 (hosts (list %files ;first, check /etc/hosts
37351 ;; If the above did not succeed, try
37352 ;; with 'mdns_minimal'.
37354 (name "mdns_minimal")
37356 ;; 'mdns_minimal' is authoritative for
37357 ;; '.local'. When it returns "not found",
37358 ;; no need to try the next methods.
37359 (reaction (lookup-specification
37360 (not-found => return))))
37362 ;; Then fall back to DNS.
37366 ;; Finally, try with the "full" 'mdns'.
37371 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
37372 contains this configuration, so you will not have to type it if all you
37373 want is to have @code{.local} host lookup working.
37375 Note that, in this case, in addition to setting the
37376 @code{name-service-switch} of the @code{operating-system} declaration,
37377 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
37378 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
37379 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
37380 to the name service cache daemon (@pxref{Base Services,
37381 @code{nscd-service}}).
37383 For convenience, the following variables provide typical NSS
37386 @defvr {Scheme Variable} %default-nss
37387 This is the default name service switch configuration, a
37388 @code{name-service-switch} object.
37391 @defvr {Scheme Variable} %mdns-host-lookup-nss
37392 This is the name service switch configuration with support for host name
37393 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
37396 The reference for name service switch configuration is given below. It
37397 is a direct mapping of the configuration file format of the C library , so
37398 please refer to the C library manual for more information (@pxref{NSS
37399 Configuration File,,, libc, The GNU C Library Reference Manual}).
37400 Compared to the configuration file format of libc NSS, it has the advantage
37401 not only of adding this warm parenthetic feel that we like, but also
37402 static checks: you will know about syntax errors and typos as soon as you
37403 run @command{guix system}.
37405 @deftp {Data Type} name-service-switch
37407 This is the data type representation the configuration of libc's name
37408 service switch (NSS). Each field below represents one of the supported
37425 The system databases handled by the NSS@. Each of these fields must be a
37426 list of @code{<name-service>} objects (see below).
37430 @deftp {Data Type} name-service
37432 This is the data type representing an actual name service and the
37433 associated lookup action.
37437 A string denoting the name service (@pxref{Services in the NSS
37438 configuration,,, libc, The GNU C Library Reference Manual}).
37440 Note that name services listed here must be visible to nscd. This is
37441 achieved by passing the @code{#:name-services} argument to
37442 @code{nscd-service} the list of packages providing the needed name
37443 services (@pxref{Base Services, @code{nscd-service}}).
37446 An action specified using the @code{lookup-specification} macro
37447 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
37448 Reference Manual}). For example:
37451 (lookup-specification (unavailable => continue)
37452 (success => return))
37457 @node Initial RAM Disk
37458 @section Initial RAM Disk
37461 @cindex initial RAM disk
37462 For bootstrapping purposes, the Linux-Libre kernel is passed an
37463 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
37464 root file system as well as an initialization script. The latter is
37465 responsible for mounting the real root file system, and for loading any
37466 kernel modules that may be needed to achieve that.
37468 The @code{initrd-modules} field of an @code{operating-system}
37469 declaration allows you to specify Linux-libre kernel modules that must
37470 be available in the initrd. In particular, this is where you would list
37471 modules needed to actually drive the hard disk where your root partition
37472 is---although the default value of @code{initrd-modules} should cover
37473 most use cases. For example, assuming you need the @code{megaraid_sas}
37474 module in addition to the default modules to be able to access your root
37475 file system, you would write:
37480 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
37483 @defvr {Scheme Variable} %base-initrd-modules
37484 This is the list of kernel modules included in the initrd by default.
37487 Furthermore, if you need lower-level customization, the @code{initrd}
37488 field of an @code{operating-system} declaration allows
37489 you to specify which initrd you would like to use. The @code{(gnu
37490 system linux-initrd)} module provides three ways to build an initrd: the
37491 high-level @code{base-initrd} procedure and the low-level
37492 @code{raw-initrd} and @code{expression->initrd} procedures.
37494 The @code{base-initrd} procedure is intended to cover most common uses.
37495 For example, if you want to add a bunch of kernel modules to be loaded
37496 at boot time, you can define the @code{initrd} field of the operating
37497 system declaration like this:
37500 (initrd (lambda (file-systems . rest)
37501 ;; Create a standard initrd but set up networking
37502 ;; with the parameters QEMU expects by default.
37503 (apply base-initrd file-systems
37504 #:qemu-networking? #t
37508 The @code{base-initrd} procedure also handles common use cases that
37509 involves using the system as a QEMU guest, or as a ``live'' system with
37510 volatile root file system.
37512 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
37513 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
37514 such as trying to guess which kernel modules and packages should be included
37515 to the initrd. An example use of @code{raw-initrd} is when a user has
37516 a custom Linux kernel configuration and default kernel modules included by
37517 @code{base-initrd} are not available.
37519 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
37520 honors several options passed on the Linux kernel command line
37521 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
37522 @code{-append} option of QEMU), notably:
37525 @item gnu.load=@var{boot}
37526 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
37527 program, once it has mounted the root file system.
37529 Guix uses this option to yield control to a boot program that runs the
37530 service activation programs and then spawns the GNU@tie{}Shepherd, the
37531 initialization system.
37533 @item root=@var{root}
37534 Mount @var{root} as the root file system. @var{root} can be a device
37535 name like @code{/dev/sda1}, a file system label, or a file system UUID.
37536 When unspecified, the device name from the root file system of the
37537 operating system declaration is used.
37539 @item rootfstype=@var{type}
37540 Set the type of the root file system. It overrides the @code{type}
37541 field of the root file system specified via the @code{operating-system}
37542 declaration, if any.
37544 @item rootflags=@var{options}
37545 Set the mount @emph{options} of the root file system. It overrides the
37546 @code{options} field of the root file system specified via the
37547 @code{operating-system} declaration, if any.
37549 @item fsck.mode=@var{mode}
37550 Whether to check the @var{root} file system for errors before mounting
37551 it. @var{mode} is one of @code{skip} (never check), @code{force} (always
37552 check), or @code{auto} to respect the root @code{<file-system>} object's
37553 @code{check?} setting (@pxref{File Systems}) and run a full scan only if
37554 the file system was not cleanly shut down.
37556 @code{auto} is the default if this option is not present or if @var{mode}
37557 is not one of the above.
37559 @item fsck.repair=@var{level}
37560 The level of repairs to perform automatically if errors are found in the
37561 @var{root} file system. @var{level} is one of @code{no} (do not write to
37562 @var{root} at all if possible), @code{yes} (repair as much as possible),
37563 or @code{preen} to repair problems considered safe to repair automatically.
37565 @code{preen} is the default if this option is not present or if @var{level}
37566 is not one of the above.
37568 @item gnu.system=@var{system}
37569 Have @file{/run/booted-system} and @file{/run/current-system} point to
37572 @item modprobe.blacklist=@var{modules}@dots{}
37573 @cindex module, black-listing
37574 @cindex black list, of kernel modules
37575 Instruct the initial RAM disk as well as the @command{modprobe} command
37576 (from the kmod package) to refuse to load @var{modules}. @var{modules}
37577 must be a comma-separated list of module names---e.g.,
37578 @code{usbkbd,9pnet}.
37581 Start a read-eval-print loop (REPL) from the initial RAM disk before it
37582 tries to load kernel modules and to mount the root file system. Our
37583 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
37584 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
37585 Manual}, for more information on Guile's REPL.
37589 Now that you know all the features that initial RAM disks produced by
37590 @code{base-initrd} and @code{raw-initrd} provide,
37591 here is how to use it and customize it further.
37594 @cindex initial RAM disk
37595 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
37596 [#:linux-modules '()] [#:mapped-devices '()] @
37597 [#:keyboard-layout #f] @
37598 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
37599 Return a derivation that builds a raw initrd. @var{file-systems} is
37600 a list of file systems to be mounted by the initrd, possibly in addition to
37601 the root file system specified on the kernel command line via @option{root}.
37602 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
37603 @var{mapped-devices} is a list of device mappings to realize before
37604 @var{file-systems} are mounted (@pxref{Mapped Devices}).
37605 @var{helper-packages} is a list of packages to be copied in the initrd.
37607 include @code{e2fsck/static} or other packages needed by the initrd to check
37608 the root file system.
37610 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
37611 the desired console keyboard layout. This is done before @var{mapped-devices}
37612 are set up and before @var{file-systems} are mounted such that, should the
37613 user need to enter a passphrase or use the REPL, this happens using the
37614 intended keyboard layout.
37616 When @var{qemu-networking?} is true, set up networking with the standard QEMU
37617 parameters. When @var{virtio?} is true, load additional modules so that the
37618 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
37620 When @var{volatile-root?} is true, the root file system is writable but any changes
37624 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
37625 [#:mapped-devices '()] [#:keyboard-layout #f] @
37626 [#:qemu-networking? #f] [#:volatile-root? #f] @
37627 [#:linux-modules '()]
37628 Return as a file-like object a generic initrd, with kernel
37629 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
37630 mounted by the initrd, possibly in addition to the root file system specified
37631 on the kernel command line via @option{root}. @var{mapped-devices} is a list of device
37632 mappings to realize before @var{file-systems} are mounted.
37634 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
37635 the desired console keyboard layout. This is done before @var{mapped-devices}
37636 are set up and before @var{file-systems} are mounted such that, should the
37637 user need to enter a passphrase or use the REPL, this happens using the
37638 intended keyboard layout.
37640 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
37642 The initrd is automatically populated with all the kernel modules necessary
37643 for @var{file-systems} and for the given options. Additional kernel
37644 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
37645 loaded at boot time in the order in which they appear.
37648 Needless to say, the initrds we produce and use embed a
37649 statically-linked Guile, and the initialization program is a Guile
37650 program. That gives a lot of flexibility. The
37651 @code{expression->initrd} procedure builds such an initrd, given the
37652 program to run in that initrd.
37654 @deffn {Scheme Procedure} expression->initrd @var{exp} @
37655 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
37656 Return as a file-like object a Linux initrd (a gzipped cpio archive)
37657 containing @var{guile} and that evaluates @var{exp}, a G-expression,
37658 upon booting. All the derivations referenced by @var{exp} are
37659 automatically copied to the initrd.
37662 @node Bootloader Configuration
37663 @section Bootloader Configuration
37666 @cindex boot loader
37668 The operating system supports multiple bootloaders. The bootloader is
37669 configured using @code{bootloader-configuration} declaration. All the
37670 fields of this structure are bootloader agnostic except for one field,
37671 @code{bootloader} that indicates the bootloader to be configured and
37674 Some of the bootloaders do not honor every field of
37675 @code{bootloader-configuration}. For instance, the extlinux
37676 bootloader does not support themes and thus ignores the @code{theme}
37679 @deftp {Data Type} bootloader-configuration
37680 The type of a bootloader configuration declaration.
37684 @item @code{bootloader}
37685 @cindex EFI, bootloader
37686 @cindex UEFI, bootloader
37687 @cindex BIOS, bootloader
37688 The bootloader to use, as a @code{bootloader} object. For now
37689 @code{grub-bootloader}, @code{grub-efi-bootloader},
37690 @code{grub-efi-netboot-bootloader}, @code{grub-efi-removable-bootloader},
37691 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
37693 @cindex ARM, bootloaders
37694 @cindex AArch64, bootloaders
37695 Available bootloaders are described in @code{(gnu bootloader @dots{})}
37696 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
37697 of bootloaders for a wide range of ARM and AArch64 systems, using the
37698 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
37700 @vindex grub-efi-bootloader
37701 @code{grub-efi-bootloader} allows to boot on modern systems using the
37702 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
37703 use if the installation image contains a @file{/sys/firmware/efi} directory
37704 when you boot it on your system.
37706 @vindex grub-bootloader
37707 @code{grub-bootloader} allows you to boot in particular Intel-based machines
37708 in ``legacy'' BIOS mode.
37710 @vindex grub-efi-netboot-bootloader
37711 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
37712 through TFTP@. In combination with an NFS root file system this allows you to
37713 build a diskless Guix system.
37715 The installation of the @code{grub-efi-netboot-bootloader} generates the
37716 content of the TFTP root directory at @code{targets} (@pxref{Bootloader
37717 Configuration, @code{targets}}), to be served by a TFTP server. You may
37718 want to mount your TFTP server directories onto the @code{targets} to
37719 move the required files to the TFTP server automatically.
37721 If you plan to use an NFS root file system as well (actually if you mount the
37722 store from an NFS share), then the TFTP server needs to serve the file
37723 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
37724 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
37725 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
37726 files from the store will be accessed by GRUB through TFTP with their normal
37727 store path, for example as
37728 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
37730 Two symlinks are created to make this possible. For each target in the
37731 @code{targets} field, the first symlink is
37732 @samp{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
37733 @file{../../../boot/grub/grub.cfg}, where @samp{target} may be
37734 @file{/boot}. In this case the link is not leaving the served TFTP root
37735 directory, but otherwise it does. The second link is
37736 @samp{target}@file{/gnu/store} and points to @file{../gnu/store}. This
37737 link is leaving the served TFTP root directory.
37739 The assumption behind all this is that you have an NFS server exporting
37740 the root file system for your Guix system, and additionally a TFTP
37741 server exporting your @code{targets} directories—usually a single
37742 @file{/boot}—from that same root file system for your Guix system. In
37743 this constellation the symlinks will work.
37745 For other constellations you will have to program your own bootloader
37746 installer, which then takes care to make necessary files from the store
37747 accessible through TFTP, for example by copying them into the TFTP root
37748 directory to your @code{targets}.
37750 It is important to note that symlinks pointing outside the TFTP root directory
37751 may need to be allowed in the configuration of your TFTP server. Further the
37752 store link exposes the whole store through TFTP@. Both points need to be
37753 considered carefully for security aspects.
37755 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
37756 NFS servers, you also need a properly configured DHCP server to make the booting
37757 over netboot possible. For all this we can currently only recommend you to look
37758 for instructions about @acronym{PXE, Preboot eXecution Environment}.
37760 @vindex grub-efi-removable-bootloader
37761 @code{grub-efi-removable-bootloader} allows you to boot your system from
37762 removable media by writing the GRUB file to the UEFI-specification location of
37763 @file{/EFI/BOOT/BOOTX64.efi} of the boot directory, usually @file{/boot/efi}.
37764 This is also useful for some UEFI firmwares that ``forget'' their configuration
37765 from their non-volatile storage. Like @code{grub-efi-bootloader}, this can only
37766 be used if the @file{/sys/firmware/efi} directory is available.
37769 This @emph{will} overwrite the GRUB file from any other operating systems that
37770 also place their GRUB file in the UEFI-specification location; making them
37774 @item @code{targets}
37775 This is a list of strings denoting the targets onto which to install the
37778 The interpretation of targets depends on the bootloader in question.
37779 For @code{grub-bootloader}, for example, they should be device names
37780 understood by the bootloader @command{installer} command, such as
37781 @code{/dev/sda} or @code{(hd0)} (@pxref{Invoking grub-install,,, grub,
37782 GNU GRUB Manual}). For @code{grub-efi-bootloader} and
37783 @code{grub-efi-removable-bootloader} they should be mount
37784 points of the EFI file system, usually @file{/boot/efi}. For
37785 @code{grub-efi-netboot-bootloader}, @code{targets} should be the mount
37786 points corresponding to TFTP root directories served by your TFTP
37789 @item @code{menu-entries} (default: @code{()})
37790 A possibly empty list of @code{menu-entry} objects (see below), denoting
37791 entries to appear in the bootloader menu, in addition to the current
37792 system entry and the entry pointing to previous system generations.
37794 @item @code{default-entry} (default: @code{0})
37795 The index of the default boot menu entry. Index 0 is for the entry of the
37798 @item @code{timeout} (default: @code{5})
37799 The number of seconds to wait for keyboard input before booting. Set to
37800 0 to boot immediately, and to -1 to wait indefinitely.
37802 @cindex keyboard layout, for the bootloader
37803 @item @code{keyboard-layout} (default: @code{#f})
37804 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
37805 layout, usually US@tie{}English (``qwerty'').
37807 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
37811 This option is currently ignored by bootloaders other than @code{grub} and
37815 @item @code{theme} (default: @var{#f})
37816 The bootloader theme object describing the theme to use. If no theme
37817 is provided, some bootloaders might use a default theme, that's true
37820 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
37821 The output terminals used for the bootloader boot menu, as a list of
37822 symbols. GRUB accepts the values: @code{console}, @code{serial},
37823 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
37824 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
37825 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
37826 configuration,,, grub,GNU GRUB manual}).
37828 @item @code{terminal-inputs} (default: @code{'()})
37829 The input terminals used for the bootloader boot menu, as a list of
37830 symbols. For GRUB, the default is the native platform terminal as
37831 determined at run-time. GRUB accepts the values: @code{console},
37832 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
37833 @code{usb_keyboard}. This field corresponds to the GRUB variable
37834 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
37837 @item @code{serial-unit} (default: @code{#f})
37838 The serial unit used by the bootloader, as an integer from 0 to 3.
37839 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
37840 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
37842 @item @code{serial-speed} (default: @code{#f})
37843 The speed of the serial interface, as an integer. For GRUB, the
37844 default value is chosen at run-time; currently GRUB chooses
37845 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
37847 @item @code{device-tree-support?} (default: @code{#t})
37848 Whether to support Linux @uref{https://en.wikipedia.org/wiki/Devicetree,
37849 device tree} files loading.
37851 This option in enabled by default. In some cases involving the
37852 @code{u-boot} bootloader, where the device tree has already been loaded
37853 in RAM, it can be handy to disable the option by setting it to
37861 Should you want to list additional boot menu entries @i{via} the
37862 @code{menu-entries} field above, you will need to create them with the
37863 @code{menu-entry} form. For example, imagine you want to be able to
37864 boot another distro (hard to imagine!), you can define a menu entry
37869 (label "The Other Distro")
37870 (linux "/boot/old/vmlinux-2.6.32")
37871 (linux-arguments '("root=/dev/sda2"))
37872 (initrd "/boot/old/initrd"))
37877 @deftp {Data Type} menu-entry
37878 The type of an entry in the bootloader menu.
37883 The label to show in the menu---e.g., @code{"GNU"}.
37885 @item @code{linux} (default: @code{#f})
37886 The Linux kernel image to boot, for example:
37889 (file-append linux-libre "/bzImage")
37892 For GRUB, it is also possible to specify a device explicitly in the
37893 file path using GRUB's device naming convention (@pxref{Naming
37894 convention,,, grub, GNU GRUB manual}), for example:
37897 "(hd0,msdos1)/boot/vmlinuz"
37900 If the device is specified explicitly as above, then the @code{device}
37901 field is ignored entirely.
37903 @item @code{linux-arguments} (default: @code{()})
37904 The list of extra Linux kernel command-line arguments---e.g.,
37905 @code{("console=ttyS0")}.
37907 @item @code{initrd} (default: @code{#f})
37908 A G-Expression or string denoting the file name of the initial RAM disk
37909 to use (@pxref{G-Expressions}).
37911 @item @code{device} (default: @code{#f})
37912 The device where the kernel and initrd are to be found---i.e., for GRUB,
37913 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
37915 This may be a file system label (a string), a file system UUID (a
37916 bytevector, @pxref{File Systems}), or @code{#f}, in which case
37917 the bootloader will search the device containing the file specified by
37918 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
37919 must @emph{not} be an OS device name such as @file{/dev/sda1}.
37921 @item @code{multiboot-kernel} (default: @code{#f})
37922 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
37923 manual}). When this field is set, a Multiboot menu-entry is generated.
37927 (file-append mach "/boot/gnumach")
37930 @item @code{multiboot-arguments} (default: @code{()})
37931 The list of extra command-line arguments for the multiboot-kernel.
37933 @item @code{multiboot-modules} (default: @code{()})
37934 The list of commands for loading Multiboot modules. For example:
37937 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
37939 (list (file-append libc "/lib/ld.so.1") "exec"
37943 @item @code{chain-loader} (default: @code{#f})
37944 A string that can be accepted by @code{grub}'s @code{chainloader}
37945 directive. This has no effect if either @code{linux} or
37946 @code{multiboot-kernel} fields are specified. The following is an
37947 example of chainloading a different GNU/Linux system.
37951 (bootloader-configuration
37956 (label "GNU/Linux")
37957 (device (uuid "1C31-A17C" 'fat))
37958 (chain-loader "/EFI/GNULinux/grubx64.efi"))))))
37967 @c FIXME: Write documentation once it's stable.
37968 For now only GRUB has theme support. GRUB themes are created using
37969 the @code{grub-theme} form, which is not fully documented yet.
37971 @deftp {Data Type} grub-theme
37972 Data type representing the configuration of the GRUB theme.
37975 @item @code{gfxmode} (default: @code{'("auto")})
37976 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
37977 @pxref{gfxmode,,, grub, GNU GRUB manual}).
37981 @deffn {Scheme Procedure} grub-theme
37982 Return the default GRUB theme used by the operating system if no
37983 @code{theme} field is specified in @code{bootloader-configuration}
37986 It comes with a fancy background image displaying the GNU and Guix
37990 For example, to override the default resolution, you may use something
37995 (bootloader-configuration
37998 (inherit (grub-theme))
37999 (gfxmode '("1024x786x32" "auto"))))))
38002 @node Invoking guix system
38003 @section Invoking @command{guix system}
38005 @cindex @command{guix system}
38006 Once you have written an operating system declaration as seen in the
38007 previous section, it can be @dfn{instantiated} using the @command{guix
38008 system} command. The synopsis is:
38011 guix system @var{options}@dots{} @var{action} @var{file}
38014 @var{file} must be the name of a file containing an
38015 @code{operating-system} declaration. @var{action} specifies how the
38016 operating system is instantiated. Currently the following values are
38021 Display available service type definitions that match the given regular
38022 expressions, sorted by relevance:
38028 $ guix system search console
38029 name: console-fonts
38030 location: gnu/services/base.scm:806:2
38031 extends: shepherd-root
38032 description: Install the given fonts on the specified ttys (fonts are per
38033 + virtual console on GNU/Linux). The value of this service is a list of
38034 + tty/font pairs. The font can be the name of a font provided by the `kbd'
38035 + package or any valid argument to `setfont', as in this example:
38037 + '(("tty1" . "LatGrkCyr-8x16")
38038 + ("tty2" . (file-append
38040 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
38041 + ("tty3" . (file-append
38043 + "/share/consolefonts/ter-132n"))) ; for HDPI
38047 location: gnu/services/base.scm:1190:2
38048 extends: shepherd-root
38049 description: Provide console login using the `mingetty' program.
38053 location: gnu/services/base.scm:860:2
38055 description: Provide a console log-in service as specified by its
38056 + configuration value, a `login-configuration' object.
38062 As for @command{guix package --search}, the result is written in
38063 @code{recutils} format, which makes it easy to filter the output
38064 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
38066 @cindex service type definition, editing
38067 @cindex editing, service type definition
38069 Edit or view the definition of the given service types.
38071 For example, the command below opens your editor, as specified by the
38072 @env{EDITOR} environment variable, on the definition of the
38073 @code{openssh} service type:
38076 guix system edit openssh
38080 Build the operating system described in @var{file}, activate it, and
38081 switch to it@footnote{This action (and the related actions
38082 @code{switch-generation} and @code{roll-back}) are usable only on
38083 systems already running Guix System.}.
38086 @c The paragraph below refers to the problem discussed at
38087 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
38088 It is highly recommended to run @command{guix pull} once before you run
38089 @command{guix system reconfigure} for the first time (@pxref{Invoking
38090 guix pull}). Failing to do that you would see an older version of Guix
38091 once @command{reconfigure} has completed.
38094 This effects all the configuration specified in @var{file}: user
38095 accounts, system services, global package list, setuid programs, etc.
38096 The command starts system services specified in @var{file} that are not
38097 currently running; if a service is currently running this command will
38098 arrange for it to be upgraded the next time it is stopped (e.g.@: by
38099 @code{herd stop X} or @code{herd restart X}).
38101 This command creates a new generation whose number is one greater than
38102 the current generation (as reported by @command{guix system
38103 list-generations}). If that generation already exists, it will be
38104 overwritten. This behavior mirrors that of @command{guix package}
38105 (@pxref{Invoking guix package}).
38107 It also adds a bootloader menu entry for the new OS configuration,
38108 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
38109 entries for older configurations to a submenu, allowing you to choose
38110 an older system generation at boot time should you need it.
38112 @cindex provenance tracking, of the operating system
38113 Upon completion, the new system is deployed under
38114 @file{/run/current-system}. This directory contains @dfn{provenance
38115 meta-data}: the list of channels in use (@pxref{Channels}) and
38116 @var{file} itself, when available. You can view it by running:
38119 guix system describe
38122 This information is useful should you later want to inspect how this
38123 particular generation was built. In fact, assuming @var{file} is
38124 self-contained, you can later rebuild generation @var{n} of your
38125 operating system with:
38128 guix time-machine \
38129 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
38130 system reconfigure \
38131 /var/guix/profiles/system-@var{n}-link/configuration.scm
38134 You can think of it as some sort of built-in version control! Your
38135 system is not just a binary artifact: @emph{it carries its own source}.
38136 @xref{Service Reference, @code{provenance-service-type}}, for more
38137 information on provenance tracking.
38139 By default, @command{reconfigure} @emph{prevents you from downgrading
38140 your system}, which could (re)introduce security vulnerabilities and
38141 also cause problems with ``stateful'' services such as database
38142 management systems. You can override that behavior by passing
38143 @option{--allow-downgrades}.
38145 @item switch-generation
38146 @cindex generations
38147 Switch to an existing system generation. This action atomically
38148 switches the system profile to the specified system generation. It
38149 also rearranges the system's existing bootloader menu entries. It
38150 makes the menu entry for the specified system generation the default,
38151 and it moves the entries for the other generations to a submenu, if
38152 supported by the bootloader being used. The next time the system
38153 boots, it will use the specified system generation.
38155 The bootloader itself is not being reinstalled when using this
38156 command. Thus, the installed bootloader is used with an updated
38157 configuration file.
38159 The target generation can be specified explicitly by its generation
38160 number. For example, the following invocation would switch to system
38164 guix system switch-generation 7
38167 The target generation can also be specified relative to the current
38168 generation with the form @code{+N} or @code{-N}, where @code{+3} means
38169 ``3 generations ahead of the current generation,'' and @code{-1} means
38170 ``1 generation prior to the current generation.'' When specifying a
38171 negative value such as @code{-1}, you must precede it with @code{--} to
38172 prevent it from being parsed as an option. For example:
38175 guix system switch-generation -- -1
38178 Currently, the effect of invoking this action is @emph{only} to switch
38179 the system profile to an existing generation and rearrange the
38180 bootloader menu entries. To actually start using the target system
38181 generation, you must reboot after running this action. In the future,
38182 it will be updated to do the same things as @command{reconfigure},
38183 like activating and deactivating services.
38185 This action will fail if the specified generation does not exist.
38188 @cindex rolling back
38189 Switch to the preceding system generation. The next time the system
38190 boots, it will use the preceding system generation. This is the inverse
38191 of @command{reconfigure}, and it is exactly the same as invoking
38192 @command{switch-generation} with an argument of @code{-1}.
38194 Currently, as with @command{switch-generation}, you must reboot after
38195 running this action to actually start using the preceding system
38198 @item delete-generations
38199 @cindex deleting system generations
38200 @cindex saving space
38201 Delete system generations, making them candidates for garbage collection
38202 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
38205 This works in the same way as @samp{guix package --delete-generations}
38206 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
38207 arguments, all system generations but the current one are deleted:
38210 guix system delete-generations
38213 You can also select the generations you want to delete. The example below
38214 deletes all the system generations that are more than two months old:
38217 guix system delete-generations 2m
38220 Running this command automatically reinstalls the bootloader with an updated
38221 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
38222 longer lists the generations that have been deleted.
38225 Build the derivation of the operating system, which includes all the
38226 configuration files and programs needed to boot and run the system.
38227 This action does not actually install anything.
38230 Populate the given directory with all the files necessary to run the
38231 operating system specified in @var{file}. This is useful for first-time
38232 installations of Guix System. For instance:
38235 guix system init my-os-config.scm /mnt
38238 copies to @file{/mnt} all the store items required by the configuration
38239 specified in @file{my-os-config.scm}. This includes configuration
38240 files, packages, and so on. It also creates other essential files
38241 needed for the system to operate correctly---e.g., the @file{/etc},
38242 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
38244 This command also installs bootloader on the targets specified in
38245 @file{my-os-config}, unless the @option{--no-bootloader} option was
38249 @cindex virtual machine
38251 @anchor{guix system vm}
38252 Build a virtual machine (VM) that contains the operating system declared
38253 in @var{file}, and return a script to run that VM.
38256 The @code{vm} action and others below
38257 can use KVM support in the Linux-libre kernel. Specifically, if the
38258 machine has hardware virtualization support, the corresponding
38259 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
38260 must exist and be readable and writable by the user and by the
38261 build users of the daemon (@pxref{Build Environment Setup}).
38264 Arguments given to the script are passed to QEMU as in the example
38265 below, which enables networking and requests 1@tie{}GiB of RAM for the
38269 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -nic user,model=virtio-net-pci
38272 It's possible to combine the two steps into one:
38275 $ $(guix system vm my-config.scm) -m 1024 -smp 2 -nic user,model=virtio-net-pci
38278 The VM shares its store with the host system.
38280 By default, the root file system of the VM is mounted volatile; the
38281 @option{--persistent} option can be provided to make it persistent
38282 instead. In that case, the VM disk-image file will be copied from the
38283 store to the @env{TMPDIR} directory to make it writable.
38285 Additional file systems can be shared between the host and the VM using
38286 the @option{--share} and @option{--expose} command-line options: the former
38287 specifies a directory to be shared with write access, while the latter
38288 provides read-only access to the shared directory.
38290 The example below creates a VM in which the user's home directory is
38291 accessible read-only, and where the @file{/exchange} directory is a
38292 read-write mapping of @file{$HOME/tmp} on the host:
38295 guix system vm my-config.scm \
38296 --expose=$HOME --share=$HOME/tmp=/exchange
38299 On GNU/Linux, the default is to boot directly to the kernel; this has
38300 the advantage of requiring only a very tiny root disk image since the
38301 store of the host can then be mounted.
38303 The @option{--full-boot} option forces a complete boot sequence, starting
38304 with the bootloader. This requires more disk space since a root image
38305 containing at least the kernel, initrd, and bootloader data files must
38308 The @option{--image-size} option can be used to specify the size of the
38311 The @option{--no-graphic} option will instruct @command{guix system} to
38312 spawn a headless VM that will use the invoking tty for IO. Among other
38313 things, this enables copy-pasting, and scrollback. Use the @kbd{ctrl-a}
38314 prefix to issue QEMU commands; e.g. @kbd{ctrl-a h} prints a help,
38315 @kbd{ctrl-a x} quits the VM, and @kbd{ctrl-a c} switches between the
38316 QEMU monitor and the VM.
38318 @cindex System images, creation in various formats
38319 @cindex Creating system images in various formats
38321 @cindex image, creating disk images
38322 The @code{image} command can produce various image types. The image
38323 type can be selected using the @option{--image-type} option. It
38324 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
38325 @option{--label} option can be used to specify a volume ID with
38326 @code{image}. By default, the root file system of a disk image is
38327 mounted non-volatile; the @option{--volatile} option can be provided to
38328 make it volatile instead. When using @code{image}, the bootloader
38329 installed on the generated image is taken from the provided
38330 @code{operating-system} definition. The following example demonstrates
38331 how to generate an image that uses the @code{grub-efi-bootloader}
38332 bootloader and boot it with QEMU:
38335 image=$(guix system image --image-type=qcow2 \
38336 gnu/system/examples/lightweight-desktop.tmpl)
38337 cp $image /tmp/my-image.qcow2
38338 chmod +w /tmp/my-image.qcow2
38339 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
38340 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
38343 When using the @code{efi-raw} image type, a raw disk image is produced;
38344 it can be copied as is to a USB stick, for instance. Assuming
38345 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
38346 the image to it using the following command:
38349 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
38352 The @code{--list-image-types} command lists all the available image
38355 @cindex creating virtual machine images
38356 When using the @code{qcow2} image type, the returned image is in qcow2
38357 format, which the QEMU emulator can efficiently use. @xref{Running Guix
38358 in a VM}, for more information on how to run the image in a virtual
38359 machine. The @code{grub-bootloader} bootloader is always used
38360 independently of what is declared in the @code{operating-system} file
38361 passed as argument. This is to make it easier to work with QEMU, which
38362 uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
38363 in the Master Boot Record (MBR).
38365 @cindex docker-image, creating docker images
38366 When using the @code{docker} image type, a Docker image is produced.
38367 Guix builds the image from scratch, not from a pre-existing Docker base
38368 image. As a result, it contains @emph{exactly} what you define in the
38369 operating system configuration file. You can then load the image and
38370 launch a Docker container using commands like the following:
38373 image_id="$(docker load < guix-system-docker-image.tar.gz)"
38374 container_id="$(docker create $image_id)"
38375 docker start $container_id
38378 This command starts a new Docker container from the specified image. It
38379 will boot the Guix system in the usual manner, which means it will
38380 start any services you have defined in the operating system
38381 configuration. You can get an interactive shell running in the container
38382 using @command{docker exec}:
38385 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
38388 Depending on what you run in the Docker container, it
38389 may be necessary to give the container additional permissions. For
38390 example, if you intend to build software using Guix inside of the Docker
38391 container, you may need to pass the @option{--privileged} option to
38392 @code{docker create}.
38394 Last, the @option{--network} option applies to @command{guix system
38395 docker-image}: it produces an image where network is supposedly shared
38396 with the host, and thus without services like nscd or NetworkManager.
38399 Return a script to run the operating system declared in @var{file}
38400 within a container. Containers are a set of lightweight isolation
38401 mechanisms provided by the kernel Linux-libre. Containers are
38402 substantially less resource-demanding than full virtual machines since
38403 the kernel, shared objects, and other resources can be shared with the
38404 host system; this also means they provide thinner isolation.
38406 Currently, the script must be run as root in order to support more than
38407 a single user and group. The container shares its store with the host
38410 As with the @code{vm} action (@pxref{guix system vm}), additional file
38411 systems to be shared between the host and container can be specified
38412 using the @option{--share} and @option{--expose} options:
38415 guix system container my-config.scm \
38416 --expose=$HOME --share=$HOME/tmp=/exchange
38419 The @option{--share} and @option{--expose} options can also be passed to
38420 the generated script to bind-mount additional directories into the
38424 This option requires Linux-libre 3.19 or newer.
38429 @var{options} can contain any of the common build options (@pxref{Common
38430 Build Options}). In addition, @var{options} can contain one of the
38434 @item --expression=@var{expr}
38435 @itemx -e @var{expr}
38436 Consider the operating-system @var{expr} evaluates to.
38437 This is an alternative to specifying a file which evaluates to an
38439 This is used to generate the Guix system installer @pxref{Building the
38440 Installation Image}).
38442 @item --system=@var{system}
38443 @itemx -s @var{system}
38444 Attempt to build for @var{system} instead of the host system type.
38445 This works as per @command{guix build} (@pxref{Invoking guix build}).
38447 @item --target=@var{triplet}
38448 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
38449 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
38450 configuration triplets,, autoconf, Autoconf}).
38454 Return the derivation file name of the given operating system without
38457 @cindex provenance tracking, of the operating system
38458 @item --save-provenance
38459 As discussed above, @command{guix system init} and @command{guix system
38460 reconfigure} always save provenance information @i{via} a dedicated
38461 service (@pxref{Service Reference, @code{provenance-service-type}}).
38462 However, other commands don't do that by default. If you wish to, say,
38463 create a virtual machine image that contains provenance information, you
38467 guix system image -t qcow2 --save-provenance config.scm
38470 That way, the resulting image will effectively ``embed its own source''
38471 in the form of meta-data in @file{/run/current-system}. With that
38472 information, one can rebuild the image to make sure it really contains
38473 what it pretends to contain; or they could use that to derive a variant
38476 @item --image-type=@var{type}
38477 @itemx -t @var{type}
38478 For the @code{image} action, create an image with given @var{type}.
38480 When this option is omitted, @command{guix system} uses the
38481 @code{efi-raw} image type.
38483 @cindex ISO-9660 format
38484 @cindex CD image format
38485 @cindex DVD image format
38486 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
38487 for burning on CDs and DVDs.
38489 @item --image-size=@var{size}
38490 For the @code{image} action, create an image of the given @var{size}.
38491 @var{size} may be a number of bytes, or it may include a unit as a
38492 suffix (@pxref{Block size, size specifications,, coreutils, GNU
38495 When this option is omitted, @command{guix system} computes an estimate
38496 of the image size as a function of the size of the system declared in
38501 For the @code{container} action, allow containers to access the host network,
38502 that is, do not create a network namespace.
38504 @item --root=@var{file}
38505 @itemx -r @var{file}
38506 Make @var{file} a symlink to the result, and register it as a garbage
38509 @item --skip-checks
38510 Skip pre-installation safety checks.
38512 By default, @command{guix system init} and @command{guix system
38513 reconfigure} perform safety checks: they make sure the file systems that
38514 appear in the @code{operating-system} declaration actually exist
38515 (@pxref{File Systems}), and that any Linux kernel modules that may be
38516 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
38517 RAM Disk}). Passing this option skips these tests altogether.
38519 @item --allow-downgrades
38520 Instruct @command{guix system reconfigure} to allow system downgrades.
38522 By default, @command{reconfigure} prevents you from downgrading your
38523 system. It achieves that by comparing the provenance info of your
38524 system (shown by @command{guix system describe}) with that of your
38525 @command{guix} command (shown by @command{guix describe}). If the
38526 commits for @command{guix} are not descendants of those used for your
38527 system, @command{guix system reconfigure} errors out. Passing
38528 @option{--allow-downgrades} allows you to bypass these checks.
38531 Make sure you understand its security implications before using
38532 @option{--allow-downgrades}.
38536 @cindex on-error strategy
38537 @cindex error strategy
38538 @item --on-error=@var{strategy}
38539 Apply @var{strategy} when an error occurs when reading @var{file}.
38540 @var{strategy} may be one of the following:
38543 @item nothing-special
38544 Report the error concisely and exit. This is the default strategy.
38547 Likewise, but also display a backtrace.
38550 Report the error and enter Guile's debugger. From there, you can run
38551 commands such as @code{,bt} to get a backtrace, @code{,locals} to
38552 display local variable values, and more generally inspect the state of the
38553 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
38554 a list of available debugging commands.
38558 Once you have built, configured, re-configured, and re-re-configured
38559 your Guix installation, you may find it useful to list the operating
38560 system generations available on disk---and that you can choose from the
38561 bootloader boot menu:
38566 Describe the running system generation: its file name, the kernel and
38567 bootloader used, etc., as well as provenance information when available.
38569 The @code{--list-installed} flag is available, with the same
38570 syntax that is used in @command{guix package --list-installed}
38571 (@pxref{Invoking guix package}). When the flag is used,
38572 the description will include a list of packages that are currently
38573 installed in the system profile, with optional filtering based on a
38574 regular expression.
38577 The @emph{running} system generation---referred to by
38578 @file{/run/current-system}---is not necessarily the @emph{current}
38579 system generation---referred to by @file{/var/guix/profiles/system}: it
38580 differs when, for instance, you chose from the bootloader menu to boot
38581 an older generation.
38583 It can also differ from the @emph{booted} system generation---referred
38584 to by @file{/run/booted-system}---for instance because you reconfigured
38585 the system in the meantime.
38588 @item list-generations
38589 List a summary of each generation of the operating system available on
38590 disk, in a human-readable way. This is similar to the
38591 @option{--list-generations} option of @command{guix package}
38592 (@pxref{Invoking guix package}).
38594 Optionally, one can specify a pattern, with the same syntax that is used
38595 in @command{guix package --list-generations}, to restrict the list of
38596 generations displayed. For instance, the following command displays
38597 generations that are up to 10 days old:
38600 $ guix system list-generations 10d
38603 The @code{--list-installed} flag may also be specified, with the same
38604 syntax that is used in @command{guix package --list-installed}. This
38605 may be helpful if trying to determine when a package was added to the
38610 The @command{guix system} command has even more to offer! The following
38611 sub-commands allow you to visualize how your system services relate to
38614 @anchor{system-extension-graph}
38617 @item extension-graph
38618 Emit to standard output the @dfn{service
38619 extension graph} of the operating system defined in @var{file}
38620 (@pxref{Service Composition}, for more information on service
38621 extensions). By default the output is in Dot/Graphviz format, but you
38622 can choose a different format with @option{--graph-backend}, as with
38623 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
38628 $ guix system extension-graph @var{file} | xdot -
38631 shows the extension relations among services.
38634 The @command{dot} program is provided by the @code{graphviz} package.
38637 @anchor{system-shepherd-graph}
38638 @item shepherd-graph
38639 Emit to standard output the @dfn{dependency
38640 graph} of shepherd services of the operating system defined in
38641 @var{file}. @xref{Shepherd Services}, for more information and for an
38644 Again, the default output format is Dot/Graphviz, but you can pass
38645 @option{--graph-backend} to select a different one.
38649 @node Invoking guix deploy
38650 @section Invoking @command{guix deploy}
38652 @cindex @command{guix deploy}
38653 We've already seen @code{operating-system} declarations used to manage a
38654 machine's configuration locally. Suppose you need to configure multiple
38655 machines, though---perhaps you're managing a service on the web that's
38656 comprised of several servers. @command{guix deploy} enables you to use those
38657 same @code{operating-system} declarations to manage multiple remote hosts at
38658 once as a logical ``deployment''.
38661 The functionality described in this section is still under development
38662 and is subject to change. Get in touch with us on
38663 @email{guix-devel@@gnu.org}!
38667 guix deploy @var{file}
38670 Such an invocation will deploy the machines that the code within @var{file}
38671 evaluates to. As an example, @var{file} might contain a definition like this:
38674 ;; This is a Guix deployment of a "bare bones" setup, with
38675 ;; no X11 display server, to a machine with an SSH daemon
38676 ;; listening on localhost:2222. A configuration such as this
38677 ;; may be appropriate for virtual machine with ports
38678 ;; forwarded to the host's loopback interface.
38680 (use-service-modules networking ssh)
38681 (use-package-modules bootloaders)
38685 (host-name "gnu-deployed")
38686 (timezone "Etc/UTC")
38687 (bootloader (bootloader-configuration
38688 (bootloader grub-bootloader)
38689 (targets '("/dev/vda"))
38690 (terminal-outputs '(console))))
38691 (file-systems (cons (file-system
38693 (device "/dev/vda1")
38695 %base-file-systems))
38697 (append (list (service dhcp-client-service-type)
38698 (service openssh-service-type
38699 (openssh-configuration
38700 (permit-root-login #t)
38701 (allow-empty-passwords? #t))))
38705 (operating-system %system)
38706 (environment managed-host-environment-type)
38707 (configuration (machine-ssh-configuration
38708 (host-name "localhost")
38709 (system "x86_64-linux")
38711 (identity "./id_rsa")
38715 The file should evaluate to a list of @var{machine} objects. This example,
38716 upon being deployed, will create a new generation on the remote system
38717 realizing the @code{operating-system} declaration @code{%system}.
38718 @code{environment} and @code{configuration} specify how the machine should be
38719 provisioned---that is, how the computing resources should be created and
38720 managed. The above example does not create any resources, as a
38721 @code{'managed-host} is a machine that is already running the Guix system and
38722 available over the network. This is a particularly simple case; a more
38723 complex deployment may involve, for example, starting virtual machines through
38724 a Virtual Private Server (VPS) provider. In such a case, a different
38725 @var{environment} type would be used.
38727 Do note that you first need to generate a key pair on the coordinator machine
38728 to allow the daemon to export signed archives of files from the store
38729 (@pxref{Invoking guix archive}), though this step is automatic on Guix
38733 # guix archive --generate-key
38737 Each target machine must authorize the key of the master machine so that it
38738 accepts store items it receives from the coordinator:
38741 # guix archive --authorize < coordinator-public-key.txt
38744 @code{user}, in this example, specifies the name of the user account to log in
38745 as to perform the deployment. Its default value is @code{root}, but root
38746 login over SSH may be forbidden in some cases. To work around this,
38747 @command{guix deploy} can log in as an unprivileged user and employ
38748 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
38749 currently installed on the remote and can be invoked non-interactively as
38750 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
38751 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
38752 be accomplished with the following operating system configuration snippet:
38756 (gnu system)) ;for %sudoers-specification
38758 (define %user "username")
38763 (plain-file "sudoers"
38764 (string-append (plain-file-content %sudoers-specification)
38765 (format #f "~a ALL = NOPASSWD: ALL~%"
38770 For more information regarding the format of the @file{sudoers} file,
38771 consult @command{man sudoers}.
38773 Once you've deployed a system on a set of machines, you may find it
38774 useful to run a command on all of them. The @option{--execute} or
38775 @option{-x} option lets you do that; the example below runs
38776 @command{uname -a} on all the machines listed in the deployment file:
38779 guix deploy @var{file} -x -- uname -a
38782 One thing you may often need to do after deployment is restart specific
38783 services on all the machines, which you can do like so:
38786 guix deploy @var{file} -x -- herd restart @var{service}
38789 The @command{guix deploy -x} command returns zero if and only if the
38790 command succeeded on all the machines.
38792 @c FIXME/TODO: Separate the API doc from the CLI doc.
38794 Below are the data types you need to know about when writing a
38797 @deftp {Data Type} machine
38798 This is the data type representing a single machine in a heterogeneous Guix
38802 @item @code{operating-system}
38803 The object of the operating system configuration to deploy.
38805 @item @code{environment}
38806 An @code{environment-type} describing how the machine should be provisioned.
38808 @item @code{configuration} (default: @code{#f})
38809 An object describing the configuration for the machine's @code{environment}.
38810 If the @code{environment} has a default configuration, @code{#f} may be used.
38811 If @code{#f} is used for an environment with no default configuration,
38812 however, an error will be thrown.
38816 @deftp {Data Type} machine-ssh-configuration
38817 This is the data type representing the SSH client parameters for a machine
38818 with an @code{environment} of @code{managed-host-environment-type}.
38821 @item @code{host-name}
38822 @item @code{build-locally?} (default: @code{#t})
38823 If false, system derivations will be built on the machine being deployed to.
38824 @item @code{system}
38825 The system type describing the architecture of the machine being deployed
38826 to---e.g., @code{"x86_64-linux"}.
38827 @item @code{authorize?} (default: @code{#t})
38828 If true, the coordinator's signing key will be added to the remote's ACL
38830 @item @code{port} (default: @code{22})
38831 @item @code{user} (default: @code{"root"})
38832 @item @code{identity} (default: @code{#f})
38833 If specified, the path to the SSH private key to use to authenticate with the
38836 @item @code{host-key} (default: @code{#f})
38837 This should be the SSH host key of the machine, which looks like this:
38840 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
38843 When @code{host-key} is @code{#f}, the server is authenticated against
38844 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
38847 @item @code{allow-downgrades?} (default: @code{#f})
38848 Whether to allow potential downgrades.
38850 Like @command{guix system reconfigure}, @command{guix deploy} compares
38851 the channel commits currently deployed on the remote host (as returned
38852 by @command{guix system describe}) to those currently in use (as
38853 returned by @command{guix describe}) to determine whether commits
38854 currently in use are descendants of those deployed. When this is not
38855 the case and @code{allow-downgrades?} is false, it raises an error.
38856 This ensures you do not accidentally downgrade remote machines.
38858 @item @code{safety-checks?} (default: @code{#t})
38859 Whether to perform ``safety checks'' before deployment. This includes
38860 verifying that devices and file systems referred to in the operating
38861 system configuration actually exist on the target machine, and making
38862 sure that Linux modules required to access storage devices at boot time
38863 are listed in the @code{initrd-modules} field of the operating system.
38865 These safety checks ensure that you do not inadvertently deploy a system
38866 that would fail to boot. Be careful before turning them off!
38870 @deftp {Data Type} digital-ocean-configuration
38871 This is the data type describing the Droplet that should be created for a
38872 machine with an @code{environment} of @code{digital-ocean-environment-type}.
38875 @item @code{ssh-key}
38876 The path to the SSH private key to use to authenticate with the remote
38877 host. In the future, this field may not exist.
38879 A list of string ``tags'' that uniquely identify the machine. Must be given
38880 such that no two machines in the deployment have the same set of tags.
38881 @item @code{region}
38882 A Digital Ocean region slug, such as @code{"nyc3"}.
38884 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
38885 @item @code{enable-ipv6?}
38886 Whether or not the droplet should be created with IPv6 networking.
38890 @node Running Guix in a VM
38891 @section Running Guix in a Virtual Machine
38893 @cindex virtual machine
38894 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM
38895 image distributed at
38896 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.qcow2}.
38897 This image is a compressed image in QCOW format. You can pass it to an
38898 emulator such as @uref{https://qemu.org/, QEMU} (see below for details).
38900 This image boots the Xfce graphical environment and it contains some
38901 commonly used tools. You can install more software in the image by running
38902 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
38903 also reconfigure the system based on its initial configuration file available
38904 as @file{/run/current-system/configuration.scm} (@pxref{Using the
38905 Configuration System}).
38907 Instead of using this pre-built image, one can also build their own
38908 image using @command{guix system image} (@pxref{Invoking guix system}).
38911 If you built your own image, you must copy it out of the store
38912 (@pxref{The Store}) and give yourself permission to write to the copy
38913 before you can use it. When invoking QEMU, you must choose a system
38914 emulator that is suitable for your hardware platform. Here is a minimal
38915 QEMU invocation that will boot the result of @command{guix system
38916 image -t qcow2} on x86_64 hardware:
38919 $ qemu-system-x86_64 \
38920 -nic user,model=virtio-net-pci \
38921 -enable-kvm -m 2048 \
38922 -device virtio-blk,drive=myhd \
38923 -drive if=none,file=/tmp/qemu-image,id=myhd
38926 Here is what each of these options means:
38929 @item qemu-system-x86_64
38930 This specifies the hardware platform to emulate. This should match the
38933 @item -nic user,model=virtio-net-pci
38934 Enable the unprivileged user-mode network stack. The guest OS can
38935 access the host but not vice versa. This is the simplest way to get the
38936 guest OS online. @code{model} specifies which network device to emulate:
38937 @code{virtio-net-pci} is a special device made for virtualized operating
38938 systems and recommended for most uses. Assuming your hardware platform is
38939 x86_64, you can get a list of available NIC models by running
38940 @command{qemu-system-x86_64 -nic model=help}.
38943 If your system has hardware virtualization extensions, enabling the
38944 virtual machine support (KVM) of the Linux kernel will make things run
38947 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
38949 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
38950 which may be insufficient for some operations.
38952 @item -device virtio-blk,drive=myhd
38953 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
38954 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
38955 better performance than if it were emulating a complete disk drive. See the
38956 QEMU and KVM documentation for more info.
38958 @item -drive if=none,file=/tmp/qemu-image,id=myhd
38959 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
38960 store of the ``myhd'' drive.
38963 The default @command{run-vm.sh} script that is returned by an invocation of
38964 @command{guix system vm} does not add a @command{-nic user} flag by default.
38965 To get network access from within the vm add the @code{(dhcp-client-service)}
38966 to your system definition and start the VM using
38967 @command{$(guix system vm config.scm) -nic user}. An important caveat of using
38968 @command{-nic user} for networking is that @command{ping} will not work, because
38969 it uses the ICMP protocol. You'll have to use a different command to check for
38970 network connectivity, for example @command{guix download}.
38972 @subsection Connecting Through SSH
38976 To enable SSH inside a VM you need to add an SSH server like
38977 @code{openssh-service-type} to your VM (@pxref{Networking Services,
38978 @code{openssh-service-type}}). In addition you need to forward the SSH port,
38979 22 by default, to the host. You can do this with
38982 $(guix system vm config.scm) -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
38985 To connect to the VM you can run
38988 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022 localhost
38991 The @command{-p} tells @command{ssh} the port you want to connect to.
38992 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
38993 every time you modify your @command{config.scm} file and the
38994 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
38995 connection to an unknown host every time you connect.
38998 If you find the above @samp{hostfwd} example not to be working (e.g.,
38999 your SSH client hangs attempting to connect to the mapped port of your
39000 VM), make sure that your Guix System VM has networking support, such as
39001 by using the @code{dhcp-client-service-type} service type.
39004 @subsection Using @command{virt-viewer} with Spice
39006 As an alternative to the default @command{qemu} graphical client you can
39007 use the @command{remote-viewer} from the @command{virt-viewer} package. To
39008 connect pass the @command{-spice port=5930,disable-ticketing} flag to
39009 @command{qemu}. See previous section for further information on how to do this.
39011 Spice also allows you to do some nice stuff like share your clipboard with your
39012 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
39015 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
39016 -chardev spicevmc,name=vdagent,id=vdagent
39017 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,\
39018 name=com.redhat.spice.0
39021 You'll also need to add the @code{(spice-vdagent-service)} to your
39022 system definition (@pxref{Miscellaneous Services, Spice service}).
39024 @node Defining Services
39025 @section Defining Services
39027 The previous sections show the available services and how one can combine
39028 them in an @code{operating-system} declaration. But how do we define
39029 them in the first place? And what is a service anyway?
39032 * Service Composition:: The model for composing services.
39033 * Service Types and Services:: Types and services.
39034 * Service Reference:: API reference.
39035 * Shepherd Services:: A particular type of service.
39036 * Complex Configurations:: Defining bindings for complex configurations.
39039 @node Service Composition
39040 @subsection Service Composition
39044 Here we define a @dfn{service} as, broadly, something that extends the
39045 functionality of the operating system. Often a service is a process---a
39046 @dfn{daemon}---started when the system boots: a secure shell server, a
39047 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
39048 whose execution can be triggered by another daemon---e.g., an FTP server
39049 started by @command{inetd} or a D-Bus service activated by
39050 @command{dbus-daemon}. Occasionally, a service does not map to a
39051 daemon. For instance, the ``account'' service collects user accounts
39052 and makes sure they exist when the system runs; the ``udev'' service
39053 collects device management rules and makes them available to the eudev
39054 daemon; the @file{/etc} service populates the @file{/etc} directory
39057 @cindex service extensions
39058 Guix system services are connected by @dfn{extensions}. For instance, the
39059 secure shell service @emph{extends} the Shepherd---the
39060 initialization system, running as PID@tie{}1---by giving it the command
39061 lines to start and stop the secure shell daemon (@pxref{Networking
39062 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
39063 service by passing it its @file{.service} specification, and extends the
39064 udev service by passing it device management rules (@pxref{Desktop
39065 Services, @code{upower-service}}); the Guix daemon service extends the
39066 Shepherd by passing it the command lines to start and stop the daemon,
39067 and extends the account service by passing it a list of required build
39068 user accounts (@pxref{Base Services}).
39070 All in all, services and their ``extends'' relations form a directed
39071 acyclic graph (DAG). If we represent services as boxes and extensions
39072 as arrows, a typical system might provide something like this:
39074 @image{images/service-graph,,5in,Typical service extension graph.}
39076 @cindex system service
39077 At the bottom, we see the @dfn{system service}, which produces the
39078 directory containing everything to run and boot the system, as returned
39079 by the @command{guix system build} command. @xref{Service Reference},
39080 to learn about the other service types shown here.
39081 @xref{system-extension-graph, the @command{guix system extension-graph}
39082 command}, for information on how to generate this representation for a
39083 particular operating system definition.
39085 @cindex service types
39086 Technically, developers can define @dfn{service types} to express these
39087 relations. There can be any number of services of a given type on the
39088 system---for instance, a system running two instances of the GNU secure
39089 shell server (lsh) has two instances of @code{lsh-service-type}, with
39090 different parameters.
39092 The following section describes the programming interface for service
39093 types and services.
39095 @node Service Types and Services
39096 @subsection Service Types and Services
39098 A @dfn{service type} is a node in the DAG described above. Let us start
39099 with a simple example, the service type for the Guix build daemon
39100 (@pxref{Invoking guix-daemon}):
39103 (define guix-service-type
39107 (list (service-extension shepherd-root-service-type guix-shepherd-service)
39108 (service-extension account-service-type guix-accounts)
39109 (service-extension activation-service-type guix-activation)))
39110 (default-value (guix-configuration))))
39114 It defines three things:
39118 A name, whose sole purpose is to make inspection and debugging easier.
39121 A list of @dfn{service extensions}, where each extension designates the
39122 target service type and a procedure that, given the parameters of the
39123 service, returns a list of objects to extend the service of that type.
39125 Every service type has at least one service extension. The only
39126 exception is the @dfn{boot service type}, which is the ultimate service.
39129 Optionally, a default value for instances of this type.
39132 In this example, @code{guix-service-type} extends three services:
39135 @item shepherd-root-service-type
39136 The @code{guix-shepherd-service} procedure defines how the Shepherd
39137 service is extended. Namely, it returns a @code{<shepherd-service>}
39138 object that defines how @command{guix-daemon} is started and stopped
39139 (@pxref{Shepherd Services}).
39141 @item account-service-type
39142 This extension for this service is computed by @code{guix-accounts},
39143 which returns a list of @code{user-group} and @code{user-account}
39144 objects representing the build user accounts (@pxref{Invoking
39147 @item activation-service-type
39148 Here @code{guix-activation} is a procedure that returns a gexp, which is
39149 a code snippet to run at ``activation time''---e.g., when the service is
39153 A service of this type is instantiated like this:
39156 (service guix-service-type
39157 (guix-configuration
39159 (extra-options '("--gc-keep-derivations"))))
39162 The second argument to the @code{service} form is a value representing
39163 the parameters of this specific service instance.
39164 @xref{guix-configuration-type, @code{guix-configuration}}, for
39165 information about the @code{guix-configuration} data type. When the
39166 value is omitted, the default value specified by
39167 @code{guix-service-type} is used:
39170 (service guix-service-type)
39173 @code{guix-service-type} is quite simple because it extends other
39174 services but is not extensible itself.
39176 @c @subsubsubsection Extensible Service Types
39178 The service type for an @emph{extensible} service looks like this:
39181 (define udev-service-type
39182 (service-type (name 'udev)
39184 (list (service-extension shepherd-root-service-type
39185 udev-shepherd-service)))
39187 (compose concatenate) ;concatenate the list of rules
39188 (extend (lambda (config rules)
39190 (($ <udev-configuration> udev initial-rules)
39191 (udev-configuration
39192 (udev udev) ;the udev package to use
39193 (rules (append initial-rules rules)))))))))
39196 This is the service type for the
39197 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
39198 management daemon}. Compared to the previous example, in addition to an
39199 extension of @code{shepherd-root-service-type}, we see two new fields:
39203 This is the procedure to @dfn{compose} the list of extensions to
39204 services of this type.
39206 Services can extend the udev service by passing it lists of rules; we
39207 compose those extensions simply by concatenating them.
39210 This procedure defines how the value of the service is @dfn{extended} with
39211 the composition of the extensions.
39213 Udev extensions are composed into a list of rules, but the udev service
39214 value is itself a @code{<udev-configuration>} record. So here, we
39215 extend that record by appending the list of rules it contains to the
39216 list of contributed rules.
39219 This is a string giving an overview of the service type. The string can
39220 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
39221 @command{guix system search} command searches these strings and displays
39222 them (@pxref{Invoking guix system}).
39225 There can be only one instance of an extensible service type such as
39226 @code{udev-service-type}. If there were more, the
39227 @code{service-extension} specifications would be ambiguous.
39229 Still here? The next section provides a reference of the programming
39230 interface for services.
39232 @node Service Reference
39233 @subsection Service Reference
39235 We have seen an overview of service types (@pxref{Service Types and
39236 Services}). This section provides a reference on how to manipulate
39237 services and service types. This interface is provided by the
39238 @code{(gnu services)} module.
39240 @deffn {Scheme Procedure} service @var{type} [@var{value}]
39241 Return a new service of @var{type}, a @code{<service-type>} object (see
39242 below). @var{value} can be any object; it represents the parameters of
39243 this particular service instance.
39245 When @var{value} is omitted, the default value specified by @var{type}
39246 is used; if @var{type} does not specify a default value, an error is
39249 For instance, this:
39252 (service openssh-service-type)
39256 is equivalent to this:
39259 (service openssh-service-type
39260 (openssh-configuration))
39263 In both cases the result is an instance of @code{openssh-service-type}
39264 with the default configuration.
39267 @deffn {Scheme Procedure} service? @var{obj}
39268 Return true if @var{obj} is a service.
39271 @deffn {Scheme Procedure} service-kind @var{service}
39272 Return the type of @var{service}---i.e., a @code{<service-type>} object.
39275 @deffn {Scheme Procedure} service-value @var{service}
39276 Return the value associated with @var{service}. It represents its
39280 Here is an example of how a service is created and manipulated:
39284 (service nginx-service-type
39285 (nginx-configuration
39287 (log-directory log-directory)
39288 (run-directory run-directory)
39289 (file config-file))))
39294 (eq? (service-kind s) nginx-service-type)
39298 The @code{modify-services} form provides a handy way to change the
39299 parameters of some of the services of a list such as
39300 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
39301 evaluates to a list of services. Of course, you could always use
39302 standard list combinators such as @code{map} and @code{fold} to do that
39303 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
39304 @code{modify-services} simply provides a more concise form for this
39307 @deffn {Scheme Syntax} modify-services @var{services} @
39308 (@var{type} @var{variable} => @var{body}) @dots{}
39310 Modify the services listed in @var{services} according to the given
39311 clauses. Each clause has the form:
39314 (@var{type} @var{variable} => @var{body})
39317 where @var{type} is a service type---e.g.,
39318 @code{guix-service-type}---and @var{variable} is an identifier that is
39319 bound within the @var{body} to the service parameters---e.g., a
39320 @code{guix-configuration} instance---of the original service of that
39323 The @var{body} should evaluate to the new service parameters, which will
39324 be used to configure the new service. This new service will replace the
39325 original in the resulting list. Because a service's service parameters
39326 are created using @code{define-record-type*}, you can write a succinct
39327 @var{body} that evaluates to the new service parameters by using the
39328 @code{inherit} feature that @code{define-record-type*} provides.
39330 Clauses can also have the following form:
39333 (delete @var{type})
39336 Such a clause removes all services of the given @var{type} from
39339 @xref{Using the Configuration System}, for example usage.
39343 Next comes the programming interface for service types. This is
39344 something you want to know when writing new service definitions, but not
39345 necessarily when simply looking for ways to customize your
39346 @code{operating-system} declaration.
39348 @deftp {Data Type} service-type
39349 @cindex service type
39350 This is the representation of a @dfn{service type} (@pxref{Service Types
39355 This is a symbol, used only to simplify inspection and debugging.
39357 @item @code{extensions}
39358 A non-empty list of @code{<service-extension>} objects (see below).
39360 @item @code{compose} (default: @code{#f})
39361 If this is @code{#f}, then the service type denotes services that cannot
39362 be extended---i.e., services that do not receive ``values'' from other
39365 Otherwise, it must be a one-argument procedure. The procedure is called
39366 by @code{fold-services} and is passed a list of values collected from
39367 extensions. It may return any single value.
39369 @item @code{extend} (default: @code{#f})
39370 If this is @code{#f}, services of this type cannot be extended.
39372 Otherwise, it must be a two-argument procedure: @code{fold-services}
39373 calls it, passing it the initial value of the service as the first
39374 argument and the result of applying @code{compose} to the extension
39375 values as the second argument. It must return a value that is a valid
39376 parameter value for the service instance.
39378 @item @code{description}
39379 This is a string, possibly using Texinfo markup, describing in a couple
39380 of sentences what the service is about. This string allows users to
39381 find about the service through @command{guix system search}
39382 (@pxref{Invoking guix system}).
39384 @item @code{default-value} (default: @code{&no-default-value})
39385 The default value associated for instances of this service type. This
39386 allows users to use the @code{service} form without its second argument:
39389 (service @var{type})
39392 The returned service in this case has the default value specified by
39396 @xref{Service Types and Services}, for examples.
39399 @deffn {Scheme Procedure} service-extension @var{target-type} @
39401 Return a new extension for services of type @var{target-type}.
39402 @var{compute} must be a one-argument procedure: @code{fold-services}
39403 calls it, passing it the value associated with the service that provides
39404 the extension; it must return a valid value for the target service.
39407 @deffn {Scheme Procedure} service-extension? @var{obj}
39408 Return true if @var{obj} is a service extension.
39411 Occasionally, you might want to simply extend an existing service. This
39412 involves creating a new service type and specifying the extension of
39413 interest, which can be verbose; the @code{simple-service} procedure
39414 provides a shorthand for this.
39416 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
39417 Return a service that extends @var{target} with @var{value}. This works
39418 by creating a singleton service type @var{name}, of which the returned
39419 service is an instance.
39421 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
39425 (simple-service 'my-mcron-job mcron-service-type
39426 #~(job '(next-hour (3)) "guix gc -F 2G"))
39430 At the core of the service abstraction lies the @code{fold-services}
39431 procedure, which is responsible for ``compiling'' a list of services
39432 down to a single directory that contains everything needed to boot and
39433 run the system---the directory shown by the @command{guix system build}
39434 command (@pxref{Invoking guix system}). In essence, it propagates
39435 service extensions down the service graph, updating each node parameters
39436 on the way, until it reaches the root node.
39438 @deffn {Scheme Procedure} fold-services @var{services} @
39439 [#:target-type @var{system-service-type}]
39440 Fold @var{services} by propagating their extensions down to the root of
39441 type @var{target-type}; return the root service adjusted accordingly.
39444 Lastly, the @code{(gnu services)} module also defines several essential
39445 service types, some of which are listed below.
39447 @defvr {Scheme Variable} system-service-type
39448 This is the root of the service graph. It produces the system directory
39449 as returned by the @command{guix system build} command.
39452 @defvr {Scheme Variable} boot-service-type
39453 The type of the ``boot service'', which produces the @dfn{boot script}.
39454 The boot script is what the initial RAM disk runs when booting.
39457 @defvr {Scheme Variable} etc-service-type
39458 The type of the @file{/etc} service. This service is used to create
39459 files under @file{/etc} and can be extended by
39460 passing it name/file tuples such as:
39463 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
39466 In this example, the effect would be to add an @file{/etc/issue} file
39467 pointing to the given file.
39470 @defvr {Scheme Variable} setuid-program-service-type
39471 Type for the ``setuid-program service''. This service collects lists of
39472 executable file names, passed as gexps, and adds them to the set of
39473 setuid and setgid programs on the system (@pxref{Setuid Programs}).
39476 @defvr {Scheme Variable} profile-service-type
39477 Type of the service that populates the @dfn{system profile}---i.e., the
39478 programs under @file{/run/current-system/profile}. Other services can
39479 extend it by passing it lists of packages to add to the system profile.
39482 @cindex provenance tracking, of the operating system
39483 @anchor{provenance-service-type}
39484 @defvr {Scheme Variable} provenance-service-type
39485 This is the type of the service that records @dfn{provenance meta-data}
39486 in the system itself. It creates several files under
39487 @file{/run/current-system}:
39491 This is a ``channel file'' that can be passed to @command{guix pull -C}
39492 or @command{guix time-machine -C}, and which describes the channels used
39493 to build the system, if that information was available
39494 (@pxref{Channels}).
39496 @item configuration.scm
39497 This is the file that was passed as the value for this
39498 @code{provenance-service-type} service. By default, @command{guix
39499 system reconfigure} automatically passes the OS configuration file it
39500 received on the command line.
39503 This contains the same information as the two other files but in a
39504 format that is more readily processable.
39507 In general, these two pieces of information (channels and configuration
39508 file) are enough to reproduce the operating system ``from source''.
39511 This information is necessary to rebuild your operating system, but it
39512 is not always sufficient. In particular, @file{configuration.scm}
39513 itself is insufficient if it is not self-contained---if it refers to
39514 external Guile modules or to extra files. If you want
39515 @file{configuration.scm} to be self-contained, we recommend that modules
39516 or files it refers to be part of a channel.
39518 Besides, provenance meta-data is ``silent'' in the sense that it does
39519 not change the bits contained in your system, @emph{except for the
39520 meta-data bits themselves}. Two different OS configurations or sets of
39521 channels can lead to the same system, bit-for-bit; when
39522 @code{provenance-service-type} is used, these two systems will have
39523 different meta-data and thus different store file names, which makes
39524 comparison less trivial.
39527 This service is automatically added to your operating system
39528 configuration when you use @command{guix system reconfigure},
39529 @command{guix system init}, or @command{guix deploy}.
39532 @defvr {Scheme Variable} linux-loadable-module-service-type
39533 Type of the service that collects lists of packages containing
39534 kernel-loadable modules, and adds them to the set of kernel-loadable
39537 This service type is intended to be extended by other service types,
39541 (simple-service 'installing-module
39542 linux-loadable-module-service-type
39543 (list module-to-install-1
39544 module-to-install-2))
39547 This does not actually load modules at bootup, only adds it to the
39548 kernel profile so that it @emph{can} be loaded by other means.
39551 @node Shepherd Services
39552 @subsection Shepherd Services
39554 @cindex shepherd services
39556 @cindex init system
39557 The @code{(gnu services shepherd)} module provides a way to define
39558 services managed by the GNU@tie{}Shepherd, which is the
39559 initialization system---the first process that is started when the
39560 system boots, also known as PID@tie{}1
39561 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
39563 Services in the Shepherd can depend on each other. For instance, the
39564 SSH daemon may need to be started after the syslog daemon has been
39565 started, which in turn can only happen once all the file systems have
39566 been mounted. The simple operating system defined earlier (@pxref{Using
39567 the Configuration System}) results in a service graph like this:
39569 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
39571 You can actually generate such a graph for any operating system
39572 definition using the @command{guix system shepherd-graph} command
39573 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
39575 The @code{%shepherd-root-service} is a service object representing
39576 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
39577 by passing it lists of @code{<shepherd-service>} objects.
39579 @deftp {Data Type} shepherd-service
39580 The data type representing a service managed by the Shepherd.
39583 @item @code{provision}
39584 This is a list of symbols denoting what the service provides.
39586 These are the names that may be passed to @command{herd start},
39587 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
39588 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
39589 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
39591 @item @code{requirement} (default: @code{'()})
39592 List of symbols denoting the Shepherd services this one depends on.
39594 @cindex one-shot services, for the Shepherd
39595 @item @code{one-shot?} (default: @code{#f})
39596 Whether this service is @dfn{one-shot}. One-shot services stop immediately
39597 after their @code{start} action has completed. @xref{Slots of services,,,
39598 shepherd, The GNU Shepherd Manual}, for more info.
39600 @item @code{respawn?} (default: @code{#t})
39601 Whether to restart the service when it stops, for instance when the
39602 underlying process dies.
39605 @itemx @code{stop} (default: @code{#~(const #f)})
39606 The @code{start} and @code{stop} fields refer to the Shepherd's
39607 facilities to start and stop processes (@pxref{Service De- and
39608 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
39609 G-expressions that get expanded in the Shepherd configuration file
39610 (@pxref{G-Expressions}).
39612 @item @code{actions} (default: @code{'()})
39613 @cindex actions, of Shepherd services
39614 This is a list of @code{shepherd-action} objects (see below) defining
39615 @dfn{actions} supported by the service, in addition to the standard
39616 @code{start} and @code{stop} actions. Actions listed here become available as
39617 @command{herd} sub-commands:
39620 herd @var{action} @var{service} [@var{arguments}@dots{}]
39623 @item @code{auto-start?} (default: @code{#t})
39624 Whether this service should be started automatically by the Shepherd. If it
39625 is @code{#f} the service has to be started manually with @code{herd start}.
39627 @item @code{documentation}
39628 A documentation string, as shown when running:
39631 herd doc @var{service-name}
39634 where @var{service-name} is one of the symbols in @code{provision}
39635 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
39637 @item @code{modules} (default: @code{%default-modules})
39638 This is the list of modules that must be in scope when @code{start} and
39639 @code{stop} are evaluated.
39644 The example below defines a Shepherd service that spawns
39645 @command{syslogd}, the system logger from the GNU Networking Utilities
39646 (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
39650 (let ((config (plain-file "syslogd.conf" "@dots{}")))
39652 (documentation "Run the syslog daemon (syslogd).")
39653 (provision '(syslogd))
39654 (requirement '(user-processes))
39655 (start #~(make-forkexec-constructor
39656 (list #$(file-append inetutils "/libexec/syslogd")
39657 "--rcfile" #$config)
39658 #:pid-file "/var/run/syslog.pid"))
39659 (stop #~(make-kill-destructor))))
39662 Key elements in this example are the @code{start} and @code{stop}
39663 fields: they are @dfn{staged} code snippets that use the
39664 @code{make-forkexec-constructor} procedure provided by the Shepherd and
39665 its dual, @code{make-kill-destructor} (@pxref{Service De- and
39666 Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
39667 field will have @command{shepherd} spawn @command{syslogd} with the
39668 given option; note that we pass @code{config} after @option{--rcfile},
39669 which is a configuration file declared above (contents of this file are
39670 omitted). Likewise, the @code{stop} field tells how this service is to
39671 be stopped; in this case, it is stopped by making the @code{kill} system
39672 call on its PID@. Code staging is achieved using G-expressions:
39673 @code{#~} stages code, while @code{#$} ``escapes'' back to host code
39674 (@pxref{G-Expressions}).
39676 @deftp {Data Type} shepherd-action
39677 This is the data type that defines additional actions implemented by a
39678 Shepherd service (see above).
39682 Symbol naming the action.
39684 @item documentation
39685 This is a documentation string for the action. It can be viewed by running:
39688 herd doc @var{service} action @var{action}
39692 This should be a gexp that evaluates to a procedure of at least one argument,
39693 which is the ``running value'' of the service (@pxref{Slots of services,,,
39694 shepherd, The GNU Shepherd Manual}).
39697 The following example defines an action called @code{say-hello} that kindly
39703 (documentation "Say hi!")
39704 (procedure #~(lambda (running . args)
39705 (format #t "Hello, friend! arguments: ~s\n"
39710 Assuming this action is added to the @code{example} service, then you can do:
39713 # herd say-hello example
39714 Hello, friend! arguments: ()
39715 # herd say-hello example a b c
39716 Hello, friend! arguments: ("a" "b" "c")
39719 This, as you can see, is a fairly sophisticated way to say hello.
39720 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
39724 @defvr {Scheme Variable} shepherd-root-service-type
39725 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
39727 This is the service type that extensions target when they want to create
39728 shepherd services (@pxref{Service Types and Services}, for an example).
39729 Each extension must pass a list of @code{<shepherd-service>}. Its
39730 value must be a @code{shepherd-configuration}, as described below.
39733 @deftp {Data Type} shepherd-configuration
39734 This data type represents the Shepherd's configuration.
39737 @item shepherd (default: @code{shepherd})
39738 The Shepherd package to use.
39740 @item services (default: @code{'()})
39741 A list of @code{<shepherd-service>} to start.
39742 You should probably use the service extension
39743 mechanism instead (@pxref{Shepherd Services}).
39747 The following example specifies the Shepherd package for the operating
39753 (services (append (list openssh-service-type))
39757 ;; Use own Shepherd package.
39758 (essential-services
39759 (modify-services (operating-system-default-essential-services
39760 this-operating-system)
39761 (shepherd-root-service-type config => (shepherd-configuration
39763 (shepherd my-shepherd))))))
39766 @defvr {Scheme Variable} %shepherd-root-service
39767 This service represents PID@tie{}1.
39770 @node Complex Configurations
39771 @subsection Complex Configurations
39772 @cindex complex configurations
39773 Some programs might have rather complex configuration files or formats,
39774 and to make it easier to create Scheme bindings for these configuration
39775 files, you can use the utilities defined in the @code{(gnu services
39776 configuration)} module.
39778 The main utility is the @code{define-configuration} macro, which you
39779 will use to define a Scheme record type (@pxref{Record Overview,,,
39780 guile, GNU Guile Reference Manual}). The Scheme record will be
39781 serialized to a configuration file by using @dfn{serializers}, which are
39782 procedures that take some kind of Scheme value and returns a
39783 G-expression (@pxref{G-Expressions}), which should, once serialized to
39784 the disk, return a string. More details are listed below.
39786 @deffn {Scheme Syntax} define-configuration @var{name} @var{clause1} @
39788 Create a record type named @code{@var{name}} that contains the
39789 fields found in the clauses.
39791 A clause can have one of the following forms:
39795 (@var{type} @var{default-value})
39796 @var{documentation})
39799 (@var{type} @var{default-value})
39800 @var{documentation}
39805 @var{documentation})
39809 @var{documentation}
39813 @var{field-name} is an identifier that denotes the name of the field in
39814 the generated record.
39816 @var{type} is the type of the value corresponding to @var{field-name};
39817 since Guile is untyped, a predicate
39818 procedure---@code{@var{type}?}---will be called on the value
39819 corresponding to the field to ensure that the value is of the correct
39820 type. This means that if say, @var{type} is @code{package}, then a
39821 procedure named @code{package?} will be applied on the value to make
39822 sure that it is indeed a @code{<package>} object.
39824 @var{default-value} is the default value corresponding to the field; if
39825 none is specified, the user is forced to provide a value when creating
39826 an object of the record type.
39828 @c XXX: Should these be full sentences or are they allow to be very
39829 @c short like package synopses?
39830 @var{documentation} is a string formatted with Texinfo syntax which
39831 should provide a description of what setting this field does.
39833 @var{serializer} is the name of a procedure which takes two arguments,
39834 the first is the name of the field, and the second is the value
39835 corresponding to the field. The procedure should return a string or
39836 G-expression (@pxref{G-Expressions}) that represents the content that
39837 will be serialized to the configuration file. If none is specified, a
39838 procedure of the name @code{serialize-@var{type}} will be used.
39840 A simple serializer procedure could look like this:
39843 (define (serialize-boolean field-name value)
39844 (let ((value (if value "true" "false")))
39845 #~(string-append #$field-name #$value)))
39848 In some cases multiple different configuration records might be defined
39849 in the same file, but their serializers for the same type might have to
39850 be different, because they have different configuration formats. For
39851 example, the @code{serialize-boolean} procedure for the Getmail service
39852 would have to be different from the one for the Transmission service. To
39853 make it easier to deal with this situation, one can specify a serializer
39854 prefix by using the @code{prefix} literal in the
39855 @code{define-configuration} form. This means that one doesn't have to
39856 manually specify a custom @var{serializer} for every field.
39859 (define (foo-serialize-string field-name value)
39862 (define (bar-serialize-string field-name value)
39865 (define-configuration foo-configuration
39868 "The name of label.")
39871 (define-configuration bar-configuration
39874 "The IPv4 address for this device.")
39878 However, in some cases you might not want to serialize any of the values
39879 of the record, to do this, you can use the @code{no-serialization}
39880 literal. There is also the @code{define-configuration/no-serialization}
39881 macro which is a shorthand of this.
39884 ;; Nothing will be serialized to disk.
39885 (define-configuration foo-configuration
39888 "Some documentation.")
39889 (no-serialization))
39891 ;; The same thing as above.
39892 (define-configuration/no-serialization bar-configuration
39895 "Some documentation."))
39899 @deffn {Scheme Syntax} define-maybe @var{type}
39900 Sometimes a field should not be serialized if the user doesn’t specify a
39901 value. To achieve this, you can use the @code{define-maybe} macro to
39902 define a ``maybe type''; if the value of a maybe type is left unset, or
39903 is set to the @code{%unset-value} value, then it will not be serialized.
39905 When defining a ``maybe type'', the corresponding serializer for the
39906 regular type will be used by default. For example, a field of type
39907 @code{maybe-string} will be serialized using the @code{serialize-string}
39908 procedure by default, you can of course change this by specifying a
39909 custom serializer procedure. Likewise, the type of the value would have
39910 to be a string, or left unspecified.
39913 (define-maybe string)
39915 (define (serialize-string field-name value)
39918 (define-configuration baz-configuration
39920 ;; If set to a string, the `serialize-string' procedure will be used
39921 ;; to serialize the string. Otherwise this field is not serialized.
39923 "The name of this module."))
39926 Like with @code{define-configuration}, one can set a prefix for the
39927 serializer name by using the @code{prefix} literal.
39930 (define-maybe integer
39933 (define (baz-serialize-integer field-name value)
39937 There is also the @code{no-serialization} literal, which when set means
39938 that no serializer will be defined for the ``maybe type'', regardless of
39939 whether its value is set or not.
39940 @code{define-maybe/no-serialization} is a shorthand for specifying the
39941 @code{no-serialization} literal.
39944 (define-maybe/no-serialization symbol)
39946 (define-configuration/no-serialization test-configuration
39953 @deffn (Scheme Procedure) maybe-value-set? @var{value}
39954 Predicate to check whether a user explicitly specified the value of a
39958 @deffn {Scheme Procedure} serialize-configuration @var{configuration} @
39960 Return a G-expression that contains the values corresponding to the
39961 @var{fields} of @var{configuration}, a record that has been generated by
39962 @code{define-configuration}. The G-expression can then be serialized to
39963 disk by using something like @code{mixed-text-file}.
39966 @deffn {Scheme Procedure} empty-serializer @var{field-name} @var{value}
39967 A serializer that just returns an empty string. The
39968 @code{serialize-package} procedure is an alias for this.
39971 Once you have defined a configuration record, you will most likely also
39972 want to document it so that other people know to use it. To help with
39973 that, there are two procedures, both of which are documented below.
39975 @deffn {Scheme Procedure} generate-documentation @var{documentation} @
39976 @var{documentation-name}
39977 Generate a Texinfo fragment from the docstrings in @var{documentation},
39978 a list of @code{(@var{label} @var{fields} @var{sub-documentation} ...)}.
39979 @var{label} should be a symbol and should be the name of the
39980 configuration record. @var{fields} should be a list of all the fields
39981 available for the configuration record.
39983 @var{sub-documentation} is a @code{(@var{field-name}
39984 @var{configuration-name})} tuple. @var{field-name} is the name of the
39985 field which takes another configuration record as its value, and
39986 @var{configuration-name} is the name of that configuration record.
39988 @var{sub-documentation} is only needed if there are nested configuration
39989 records. For example, the @code{getmail-configuration} record
39990 (@pxref{Mail Services}) accepts a @code{getmail-configuration-file}
39991 record in one of its @code{rcfile} field, therefore documentation for
39992 @code{getmail-configuration-file} is nested in
39993 @code{getmail-configuration}.
39996 (generate-documentation
39997 `((getmail-configuration ,getmail-configuration-fields
39998 (rcfile getmail-configuration-file))
40000 'getmail-configuration)
40003 @var{documentation-name} should be a symbol and should be the name of
40004 the configuration record.
40008 @deffn {Scheme Procedure} configuration->documentation
40009 @var{configuration-symbol}
40010 Take @var{configuration-symbol}, the symbol corresponding to the name
40011 used when defining a configuration record with
40012 @code{define-configuration}, and print the Texinfo documentation of its
40013 fields. This is useful if there aren’t any nested configuration records
40014 since it only prints the documentation for the top-level fields.
40017 As of right now, there is no automated way to generate documentation for
40018 configuration records and put them in the manual. Instead, every
40019 time you make a change to the docstrings of a configuration record, you
40020 have to manually call @code{generate-documentation} or
40021 @code{configuration->documentation}, and paste the output into the
40022 @file{doc/guix.texi} file.
40024 @c TODO: Actually test this
40025 Below is an example of a record type created using
40026 @code{define-configuration} and friends.
40029 (use-modules (gnu services)
40031 (gnu services configuration)
40035 ;; Turn field names, which are Scheme symbols into strings
40036 (define (uglify-field-name field-name)
40037 (let ((str (symbol->string field-name)))
40038 ;; field? -> is-field
40039 (if (string-suffix? "?" str)
40040 (string-append "is-" (string-drop-right str 1))
40043 (define (serialize-string field-name value)
40044 #~(string-append #$(uglify-field-name field-name) " = " #$value "\n"))
40046 (define (serialize-integer field-name value)
40047 (serialize-string field-name (number->string value)))
40049 (define (serialize-boolean field-name value)
40050 (serialize-string field-name (if value "true" "false")))
40052 (define (serialize-contact-name field-name value)
40053 #~(string-append "\n[" #$value "]\n"))
40055 (define (list-of-contact-configurations? lst)
40056 (every contact-configuration? lst))
40058 (define (serialize-list-of-contact-configurations field-name value)
40059 #~(string-append #$@@(map (cut serialize-configuration <>
40060 contact-configuration-fields)
40063 (define (serialize-contacts-list-configuration configuration)
40066 #~(string-append "[Owner]\n"
40067 #$(serialize-configuration
40068 configuration contacts-list-configuration-fields))))
40070 (define-maybe integer)
40071 (define-maybe string)
40073 (define-configuration contact-configuration
40076 "The name of the contact."
40077 serialize-contact-name)
40080 "The person's phone number.")
40083 "The person's email address.")
40086 "Whether the person is married."))
40088 (define-configuration contacts-list-configuration
40091 "The name of the owner of this contact list.")
40094 "The owner's email address.")
40096 (list-of-contact-configurations '())
40097 "A list of @@code@{contact-configuation@} records which contain
40098 information about all your contacts."))
40101 A contacts list configuration could then be created like this:
40104 (define my-contacts
40105 (contacts-list-configuration
40107 (email "alice@@example.org")
40109 (list (contact-configuration
40111 (phone-number 1234)
40112 (email "bob@@gnu.org")
40114 (contact-configuration
40116 (phone-number 0000)
40120 After serializing the configuration to disk, the resulting file would
40126 email = alice@@example.org
40129 phone-number = 1234
40130 email = bob@@gnu.org
40139 @node Home Configuration
40140 @chapter Home Configuration
40141 @cindex home configuration
40142 Guix supports declarative configuration of @dfn{home environments} by
40143 utilizing the configuration mechanism described in the previous chapter
40144 (@pxref{Defining Services}), but for user's dotfiles and packages. It
40145 works both on Guix System and foreign distros and allows users to
40146 declare all the packages and services that should be installed and
40147 configured for the user. Once a user has written a file containing
40148 @code{home-environment} record, such a configuration can be
40149 @dfn{instantiated} by an unprivileged user with the @command{guix home}
40150 command (@pxref{Invoking guix home}).
40151 @c Maybe later, it will be possible to make home configuration a part of
40152 @c system configuration to make everything managed by guix system.
40155 The functionality described in this section is still under development
40156 and is subject to change. Get in touch with us on
40157 @email{guix-devel@@gnu.org}!
40160 The user's home environment usually consists of three basic parts:
40161 software, configuration, and state. Software in mainstream distros are
40162 usually installed system-wide, but with GNU Guix most software packages
40163 can be installed on a per-user basis without needing root privileges,
40164 and are thus considered part of the user’s @dfn{home environment}.
40165 Packages on their own are not very useful in many cases, because often they
40166 require some additional configuration, usually config files that reside
40167 in @env{XDG_CONFIG_HOME} (@file{~/.config} by default) or other
40168 directories. Everything else can be considered state, like media files,
40169 application databases, and logs.
40171 Using Guix for managing home environments provides a number of
40176 @item All software can be configured in one language (Guile Scheme),
40177 this gives users the ability to share values between configurations of
40178 different programs.
40180 @item A well-defined home environment is self-contained and can be
40181 created in a declarative and reproducible way---there is no need to grab
40182 external binaries or manually edit some configuration file.
40184 @item After every @command{guix home reconfigure} invocation, a new home
40185 environment generation will be created. This means that users can
40186 rollback to a previous home environment generation so they don’t have to
40187 worry about breaking their configuration.
40189 @item It is possible to manage stateful data with Guix Home, this
40190 includes the ability to automatically clone Git repositories on the
40191 initial setup of the machine, and periodically running commands like
40192 @command{rsync} to sync data with another host. This functionality is
40193 still in an experimental stage, though.
40198 * Declaring the Home Environment:: Customizing your Home.
40199 * Configuring the Shell:: Enabling home environment.
40200 * Home Services:: Specifying home services.
40201 * Invoking guix home:: Instantiating a home configuration.
40204 @node Declaring the Home Environment
40205 @section Declaring the Home Environment
40206 The home environment is configured by providing a
40207 @code{home-environment} declaration in a file that can be passed to the
40208 @command{guix home} command (@pxref{Invoking guix home}). The easiest
40209 way to get started is by generating an initial configuration with
40210 @command{guix home import}:
40213 guix home import ~/src/guix-config
40216 The @command{guix home import} command reads some of the ``dot files''
40217 such as @file{~/.bashrc} found in your home directory and copies them to
40218 the given directory, @file{~/src/guix-config} in this case; it also
40219 reads the contents of your profile, @file{~/.guix-profile}, and, based
40220 on that, it populates @file{~/src/guix-config/home-configuration.scm}
40221 with a Home configuration that resembles your current configuration.
40223 A simple setup can include Bash and a custom text configuration, like in
40224 the example below. Don't be afraid to declare home environment parts,
40225 which overlaps with your current dot files: before installing any
40226 configuration files, Guix Home will back up existing config files to a
40227 separate place in the home directory.
40230 It is highly recommended that you manage your shell or shells with Guix
40231 Home, because it will make sure that all the necessary scripts are
40232 sourced by the shell configuration file. Otherwise you will need to do
40233 it manually. (@pxref{Configuring the Shell}).
40236 @findex home-environment
40238 @include he-config-bare-bones.scm
40241 The @code{packages} field should be self-explanatory, it will install
40242 the list of packages into the user's profile. The most important field
40243 is @code{services}, it contains a list of @dfn{home services}, which are
40244 the basic building blocks of a home environment.
40246 There is no daemon (at least not necessarily) related to a home service,
40247 a home service is just an element that is used to declare part of home
40248 environment and extend other parts of it. The extension mechanism
40249 discussed in the previous chapter (@pxref{Defining Services}) should not
40250 be confused with Shepherd services (@pxref{Shepherd Services}). Using this extension
40251 mechanism and some Scheme code that glues things together gives the user
40252 the freedom to declare their own, very custom, home environments.
40254 @cindex container, for @command{guix home}
40255 Once the configuration looks good, you can first test it in a throw-away
40259 guix home container config.scm
40262 The command above spawns a shell where your home environment is running.
40263 The shell runs in a container, meaning it's isolated from the rest of
40264 the system, so it's a good way to try out your configuration---you can
40265 see if configuration bits are missing or misbehaving, if daemons get
40266 started, and so on. Once you exit that shell, you're back to the prompt
40267 of your original shell ``in the real world''.
40269 Once you have a configuration file that suits your needs, you can
40270 reconfigure your home by running:
40273 guix home reconfigure config.scm
40276 This ``builds'' your home environment and creates @file{~/.guix-home}
40277 pointing to it. Voilà!
40280 Make sure the operating system has elogind, systemd, or a similar
40281 mechanism to create the XDG run-time directory and has the
40282 @env{XDG_RUNTIME_DIR} variable set. Failing that, the
40283 @file{on-first-login} script will not execute anything, and processes
40284 like user Shepherd and its descendants will not start.
40287 @node Configuring the Shell
40288 @section Configuring the Shell
40289 This section is safe to skip if your shell or shells are managed by
40290 Guix Home. Otherwise, read it carefully.
40292 There are a few scripts that must be evaluated by a login shell to
40293 activate the home environment. The shell startup files only read by
40294 login shells often have @code{profile} suffix. For more information
40295 about login shells see @ref{Invoking Bash,,, bash, The GNU Bash
40296 Reference Manual} and see @ref{Bash Startup Files,,, bash, The GNU Bash
40299 The first script that needs to be sourced is @file{setup-environment},
40300 which sets all the necessary environment variables (including variables
40301 declared by the user) and the second one is @file{on-first-login}, which
40302 starts Shepherd for the current user and performs actions declared by
40303 other home services that extends
40304 @code{home-run-on-first-login-service-type}.
40306 Guix Home will always create @file{~/.profile}, which contains the
40310 HOME_ENVIRONMENT=$HOME/.guix-home
40311 . $HOME_ENVIRONMENT/setup-environment
40312 $HOME_ENVIRONMENT/on-first-login
40315 This makes POSIX compliant login shells activate the home environment.
40316 However, in most cases this file won't be read by most modern shells,
40317 because they are run in non POSIX mode by default and have their own
40318 @file{*profile} startup files. For example Bash will prefer
40319 @file{~/.bash_profile} in case it exists and only if it doesn't will it
40320 fallback to @file{~/.profile}. Zsh (if no additional options are
40321 specified) will ignore @file{~/.profile}, even if @file{~/.zprofile}
40324 To make your shell respect @file{~/.profile}, add @code{. ~/.profile} or
40325 @code{source ~/.profile} to the startup file for the login shell. In
40326 case of Bash, it is @file{~/.bash_profile}, and in case of Zsh, it is
40327 @file{~/.zprofile}.
40330 This step is only required if your shell is @emph{not} managed by Guix Home.
40331 Otherwise, everything will be done automatically.
40334 @node Home Services
40335 @section Home Services
40336 @cindex home services
40338 A @dfn{home service} is not necessarily something that has a daemon and
40339 is managed by Shepherd (@pxref{Jump Start,,, shepherd, The GNU Shepherd
40340 Manual}), in most cases it doesn't. It's a simple building block of the
40341 home environment, often declaring a set of packages to be installed in
40342 the home environment profile, a set of config files to be symlinked into
40343 @env{XDG_CONFIG_HOME} (@file{~/.config} by default), and environment
40344 variables to be set by a login shell.
40346 There is a service extension mechanism (@pxref{Service Composition})
40347 which allows home services to extend other home services and utilize
40348 capabilities they provide; for example: declare mcron jobs
40349 (@pxref{Top,,, mcron, GNU@tie{}Mcron}) by extending @ref{Mcron Home
40350 Service}; declare daemons by extending @ref{Shepherd Home Service}; add
40351 commands, which will be invoked on by the Bash by extending
40352 @ref{Shells Home Services, @code{home-bash-service-type}}.
40354 A good way to discover available home services is using the
40355 @command{guix home search} command (@pxref{Invoking guix home}). After
40356 the required home services are found, include its module with the
40357 @code{use-modules} form (@pxref{use-modules,, Using Guile Modules,
40358 guile, The GNU Guile Reference Manual}), or the @code{#:use-modules}
40359 directive (@pxref{define-module,, Creating Guile Modules, guile, The GNU
40360 Guile Reference Manual}) and declare a home service using the
40361 @code{service} function, or extend a service type by declaring a new
40362 service with the @code{simple-service} procedure from @code{(gnu
40366 * Essential Home Services:: Environment variables, packages, on-* scripts.
40367 * Shells: Shells Home Services. POSIX shells, Bash, Zsh.
40368 * Mcron: Mcron Home Service. Scheduled User's Job Execution.
40369 * Power Management: Power Management Home Services. Services for battery power.
40370 * Shepherd: Shepherd Home Service. Managing User's Daemons.
40371 * SSH: Secure Shell. Setting up the secure shell client.
40372 * Desktop: Desktop Home Services. Services for graphical environments.
40373 * Guix: Guix Home Services. Services for Guix.
40375 @c In addition to that Home Services can provide
40377 @node Essential Home Services
40378 @subsection Essential Home Services
40379 There are a few essential home services defined in
40380 @code{(gnu services)}, they are mostly for internal use and are required
40381 to build a home environment, but some of them will be useful for the end
40384 @cindex environment variables
40386 @defvr {Scheme Variable} home-environment-variables-service-type
40387 The service of this type will be instantiated by every home environment
40388 automatically by default, there is no need to define it, but someone may
40389 want to extend it with a list of pairs to set some environment
40393 (list ("ENV_VAR1" . "value1")
40394 ("ENV_VAR2" . "value2"))
40397 The easiest way to extend a service type, without defining a new service
40398 type is to use the @code{simple-service} helper from @code{(gnu
40402 (simple-service 'some-useful-env-vars-service
40403 home-environment-variables-service-type
40404 `(("LESSHISTFILE" . "$XDG_CACHE_HOME/.lesshst")
40405 ("SHELL" . ,(file-append zsh "/bin/zsh"))
40406 ("USELESS_VAR" . #f)
40407 ("_JAVA_AWT_WM_NONREPARENTING" . #t)))
40410 If you include such a service in you home environment definition, it
40411 will add the following content to the @file{setup-environment} script
40412 (which is expected to be sourced by the login shell):
40415 export LESSHISTFILE=$XDG_CACHE_HOME/.lesshst
40416 export SHELL=/gnu/store/2hsg15n644f0glrcbkb1kqknmmqdar03-zsh-5.8/bin/zsh
40417 export _JAVA_AWT_WM_NONREPARENTING
40421 Make sure that module @code{(gnu packages shells)} is imported with
40422 @code{use-modules} or any other way, this namespace contains the
40423 definition of the @code{zsh} package, which is used in the example
40427 The association list (@pxref{Association Lists, alists, Association
40428 Lists, guile, The GNU Guile Reference manual}) is a data structure
40429 containing key-value pairs, for
40430 @code{home-environment-variables-service-type} the key is always a
40431 string, the value can be a string, string-valued gexp
40432 (@pxref{G-Expressions}), file-like object (@pxref{G-Expressions,
40433 file-like object}) or boolean. For gexps, the variable will be set to
40434 the value of the gexp; for file-like objects, it will be set to the path
40435 of the file in the store (@pxref{The Store}); for @code{#t}, it will
40436 export the variable without any value; and for @code{#f}, it will omit
40441 @defvr {Scheme Variable} home-profile-service-type
40442 The service of this type will be instantiated by every home environment
40443 automatically, there is no need to define it, but you may want to extend
40444 it with a list of packages if you want to install additional packages
40445 into your profile. Other services, which need to make some programs
40446 available to the user will also extend this service type.
40448 The extension value is just a list of packages:
40451 (list htop vim emacs)
40454 The same approach as @code{simple-service} (@pxref{Service Reference,
40455 simple-service}) for @code{home-environment-variables-service-type} can
40456 be used here, too. Make sure that modules containing the specified
40457 packages are imported with @code{use-modules}. To find a package or
40458 information about its module use @command{guix search} (@pxref{Invoking
40459 guix package}). Alternatively, @code{specification->package} can be
40460 used to get the package record from string without importing related
40464 There are few more essential services, but users are not expected to
40467 @defvr {Scheme Variable} home-service-type
40468 The root of home services DAG, it generates a folder, which later will be
40469 symlinked to @file{~/.guix-home}, it contains configurations,
40470 profile with binaries and libraries, and some necessary scripts to glue
40474 @defvr {Scheme Variable} home-run-on-first-login-service-type
40475 The service of this type generates a Guile script, which is expected to
40476 be executed by the login shell. It is only executed if the special flag
40477 file inside @env{XDG_RUNTIME_DIR} hasn't been created, this prevents
40478 redundant executions of the script if multiple login shells are spawned.
40480 It can be extended with a gexp. However, to autostart an application,
40481 users @emph{should not} use this service, in most cases it's better to extend
40482 @code{home-shepherd-service-type} with a Shepherd service
40483 (@pxref{Shepherd Services}), or extend the shell's startup file with
40484 the required command using the appropriate service type.
40487 @defvr {Scheme Variable} home-files-service-type
40488 The service of this type allows to specify a list of files, which will
40489 go to @file{~/.guix-home/files}, usually this directory contains
40490 configuration files (to be more precise it contains symlinks to files in
40491 @file{/gnu/store}), which should be placed in @file{$XDG_CONFIG_DIR} or
40492 in rare cases in @file{$HOME}. It accepts extension values in the
40496 `((".sway/config" ,sway-file-like-object)
40497 (".tmux.conf" ,(local-file "./tmux.conf")))
40500 Each nested list contains two values: a subdirectory and file-like
40501 object. After building a home environment @file{~/.guix-home/files}
40502 will be populated with apropiate content and all nested directories will
40503 be created accordingly, however, those files won't go any further until
40504 some other service will do it. By default a
40505 @code{home-symlink-manager-service-type}, which creates necessary
40506 symlinks in home folder to files from @file{~/.guix-home/files} and
40507 backs up already existing, but clashing configs and other things, is a
40508 part of essential home services (enabled by default), but it's possible
40509 to use alternative services to implement more advanced use cases like
40510 read-only home. Feel free to experiment and share your results.
40513 @defvr {Scheme Variable} home-xdg-configuration-files-service-type
40514 The service is very similiar to @code{home-files-service-type} (and
40515 actually extends it), but used for defining files, which will go to
40516 @file{~/.guix-home/files/.config}, which will be symlinked to
40517 @file{$XDG_CONFIG_DIR} by @code{home-symlink-manager-service-type} (for
40518 example) during activation. It accepts extension values in the
40522 `(("sway/config" ,sway-file-like-object)
40523 ;; -> ~/.guix-home/files/.config/sway/config
40524 ;; -> $XDG_CONFIG_DIR/sway/config (by symlink-manager)
40525 ("tmux/tmux.conf" ,(local-file "./tmux.conf")))
40529 @defvr {Scheme Variable} home-activation-service-type
40530 The service of this type generates a guile script, which runs on every
40531 @command{guix home reconfigure} invocation or any other action, which
40532 leads to the activation of the home environment.
40535 @defvr {Scheme Variable} home-symlink-manager-service-type
40536 The service of this type generates a guile script, which will be
40537 executed during activation of home environment, and do a few following
40542 Reads the content of @file{files/} directory of current and pending home
40546 Cleans up all symlinks created by symlink-manager on previous
40547 activation. Also, sub-directories, which become empty also will be
40551 Creates new symlinks the following way: It looks @file{files/} directory
40552 (usually defined with @code{home-files-service-type},
40553 @code{home-xdg-configuration-files-service-type} and maybe some others),
40554 takes the files from @file{files/.config/} subdirectory and put
40555 respective links in @env{XDG_CONFIG_DIR}. For example symlink for
40556 @file{files/.config/sway/config} will end up in
40557 @file{$XDG_CONFIG_DIR/sway/config}. The rest files in @file{files/}
40558 outside of @file{files/.config/} subdirectory will be treated slightly
40559 different: symlink will just go to @file{$HOME}.
40560 @file{files/.some-program/config} will end up in
40561 @file{$HOME/.some-program/config}.
40564 If some sub-directories are missing, they will be created.
40567 If there is a clashing files on the way, they will be backed up.
40571 symlink-manager is a part of essential home services and is enabled and
40576 @node Shells Home Services
40580 @cindex login shell
40581 @cindex interactive shell
40585 Shells play a quite important role in the environment initialization
40586 process, you can configure them manually as described in section
40587 @ref{Configuring the Shell}, but the recommended way is to use home services
40588 listed below. It's both easier and more reliable.
40590 Each home environment instantiates
40591 @code{home-shell-profile-service-type}, which creates a
40592 @file{~/.profile} startup file for all POSIX-compatible shells. This
40593 file contains all the necessary steps to properly initialize the
40594 environment, but many modern shells like Bash or Zsh prefer their own
40595 startup files, that's why the respective home services
40596 (@code{home-bash-service-type} and @code{home-zsh-service-type}) ensure
40597 that @file{~/.profile} is sourced by @file{~/.bash_profile} and
40598 @file{~/.zprofile}, respectively.
40600 @subsubheading Shell Profile Service
40602 @deftp {Data Type} home-shell-profile-configuration
40603 Available @code{home-shell-profile-configuration} fields are:
40606 @item @code{profile} (default: @code{()}) (type: text-config)
40607 @code{home-shell-profile} is instantiated automatically by
40608 @code{home-environment}, DO NOT create this service manually, it can
40609 only be extended. @code{profile} is a list of file-like objects, which
40610 will go to @file{~/.profile}. By default @file{~/.profile} contains the
40611 initialization code which must be evaluated by the login shell to make
40612 home-environment's profile available to the user, but other commands can
40613 be added to the file if it is really necessary. In most cases shell's
40614 configuration files are preferred places for user's customizations.
40615 Extend home-shell-profile service only if you really know what you do.
40621 @subsubheading Bash Home Service
40623 @anchor{home-bash-configuration}
40624 @deftp {Data Type} home-bash-configuration
40625 Available @code{home-bash-configuration} fields are:
40628 @item @code{package} (default: @code{bash}) (type: package)
40629 The Bash package to use.
40631 @item @code{guix-defaults?} (default: @code{#t}) (type: boolean)
40632 Add sane defaults like reading @file{/etc/bashrc} and coloring the output of
40633 @command{ls} to the top of the @file{.bashrc} file.
40635 @item @code{environment-variables} (default: @code{()}) (type: alist)
40636 Association list of environment variables to set for the Bash session. The
40637 rules for the @code{home-environment-variables-service-type} apply
40638 here (@pxref{Essential Home Services}). The contents of this field will be
40639 added after the contents of the @code{bash-profile} field.
40641 @item @code{aliases} (default: @code{()}) (type: alist)
40642 Association list of aliases to set for the Bash session. The aliases
40643 will be defined after the contents of the @code{bashrc} field has been
40644 put in the @file{.bashrc} file. The alias will automatically be quoted,
40645 so something like this:
40648 '(("ls" . "ls -alF"))
40657 @item @code{bash-profile} (default: @code{()}) (type: text-config)
40658 List of file-like objects, which will be added to @file{.bash_profile}.
40659 Used for executing user's commands at start of login shell (In most
40660 cases the shell started on tty just after login). @file{.bash_login}
40661 won't be ever read, because @file{.bash_profile} always present.
40663 @item @code{bashrc} (default: @code{()}) (type: text-config)
40664 List of file-like objects, which will be added to @file{.bashrc}. Used
40665 for executing user's commands at start of interactive shell (The shell
40666 for interactive usage started by typing @code{bash} or by terminal app
40667 or any other program).
40669 @item @code{bash-logout} (default: @code{()}) (type: text-config)
40670 List of file-like objects, which will be added to @file{.bash_logout}.
40671 Used for executing user's commands at the exit of login shell. It won't
40672 be read in some cases (if the shell terminates by exec'ing another
40673 process for example).
40678 You can extend the Bash service by using the @code{home-bash-extension}
40679 configuration record, whose fields must mirror that of
40680 @code{home-bash-configuration} (@pxref{home-bash-configuration}). The
40681 contents of the extensions will be added to the end of the corresponding
40682 Bash configuration files (@pxref{Bash Startup Files,,, bash, The GNU
40683 Bash Reference Manual}.
40685 For example, here is how you would define a service that extends the
40686 Bash service such that @file{~/.bash_profile} defines an additional
40687 environment variable, @env{PS1}:
40690 (define bash-fancy-prompt-service
40691 (simple-service 'bash-fancy-prompt
40692 home-bash-service-type
40693 (home-bash-extension
40694 (environment-variables
40695 '(("PS1" . "\\u \\wλ "))))))
40698 You would then add @code{bash-fancy-prompt-service} to the list in the
40699 @code{services} field of your @code{home-environment}. The reference of
40700 @code{home-bash-extension} follows.
40702 @deftp {Data Type} home-bash-extension
40703 Available @code{home-bash-extension} fields are:
40706 @item @code{environment-variables} (default: @code{()}) (type: alist)
40707 Additional environment variables to set. These will be combined with the
40708 environment variables from other extensions and the base service to form one
40709 coherent block of environment variables.
40711 @item @code{aliases} (default: @code{()}) (type: alist)
40712 Additional aliases to set. These will be combined with the aliases from
40713 other extensions and the base service.
40715 @item @code{bash-profile} (default: @code{()}) (type: text-config)
40716 Additional text blocks to add to @file{.bash_profile}, which will be combined
40717 with text blocks from other extensions and the base service.
40719 @item @code{bashrc} (default: @code{()}) (type: text-config)
40720 Additional text blocks to add to @file{.bashrc}, which will be combined
40721 with text blocks from other extensions and the base service.
40723 @item @code{bash-logout} (default: @code{()}) (type: text-config)
40724 Additional text blocks to add to @file{.bash_logout}, which will be combined
40725 with text blocks from other extensions and the base service.
40730 @subsubheading Zsh Home Service
40732 @deftp {Data Type} home-zsh-configuration
40733 Available @code{home-zsh-configuration} fields are:
40736 @item @code{package} (default: @code{zsh}) (type: package)
40737 The Zsh package to use.
40739 @item @code{xdg-flavor?} (default: @code{#t}) (type: boolean)
40740 Place all the configs to @file{$XDG_CONFIG_HOME/zsh}. Makes
40741 @file{~/.zshenv} to set @env{ZDOTDIR} to @file{$XDG_CONFIG_HOME/zsh}.
40742 Shell startup process will continue with
40743 @file{$XDG_CONFIG_HOME/zsh/.zshenv}.
40745 @item @code{environment-variables} (default: @code{()}) (type: alist)
40746 Association list of environment variables to set for the Zsh session.
40748 @item @code{zshenv} (default: @code{()}) (type: text-config)
40749 List of file-like objects, which will be added to @file{.zshenv}. Used
40750 for setting user's shell environment variables. Must not contain
40751 commands assuming the presence of tty or producing output. Will be read
40752 always. Will be read before any other file in @env{ZDOTDIR}.
40754 @item @code{zprofile} (default: @code{()}) (type: text-config)
40755 List of file-like objects, which will be added to @file{.zprofile}. Used
40756 for executing user's commands at start of login shell (In most cases the
40757 shell started on tty just after login). Will be read before
40760 @item @code{zshrc} (default: @code{()}) (type: text-config)
40761 List of file-like objects, which will be added to @file{.zshrc}. Used
40762 for executing user's commands at start of interactive shell (The shell
40763 for interactive usage started by typing @code{zsh} or by terminal app or
40764 any other program).
40766 @item @code{zlogin} (default: @code{()}) (type: text-config)
40767 List of file-like objects, which will be added to @file{.zlogin}. Used
40768 for executing user's commands at the end of starting process of login
40771 @item @code{zlogout} (default: @code{()}) (type: text-config)
40772 List of file-like objects, which will be added to @file{.zlogout}. Used
40773 for executing user's commands at the exit of login shell. It won't be
40774 read in some cases (if the shell terminates by exec'ing another process
40781 @node Mcron Home Service
40782 @subsection Scheduled User's Job Execution
40786 @cindex scheduling jobs
40788 The @code{(gnu home services mcron)} module provides an interface to
40789 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
40790 mcron, GNU@tie{}mcron}). The information about system's mcron is
40791 applicable here (@pxref{Scheduled Job Execution}), the only difference
40792 for home services is that they have to be declared in a
40793 @code{home-environment} record instead of an @code{operating-system}
40796 @defvr {Scheme Variable} home-mcron-service-type
40797 This is the type of the @code{mcron} home service, whose value is an
40798 @code{home-mcron-configuration} object. It allows to manage scheduled
40801 This service type can be the target of a service extension that provides
40802 additional job specifications (@pxref{Service Composition}). In other
40803 words, it is possible to define services that provide additional mcron
40807 @deftp {Data Type} home-mcron-configuration
40808 Data type representing the configuration of mcron.
40811 @item @code{mcron} (default: @var{mcron})
40812 The mcron package to use.
40815 This is a list of gexps (@pxref{G-Expressions}), where each gexp
40816 corresponds to an mcron job specification (@pxref{Syntax, mcron job
40817 specifications,, mcron, GNU@tie{}mcron}).
40821 @node Power Management Home Services
40822 @subsection Power Management Home Services
40824 @cindex power management
40825 The @code{(gnu home services pm)} module provides home services
40826 pertaining to battery power.
40828 @defvr {Scheme Variable} home-batsignal-service-type
40829 Service for @code{batsignal}, a program that monitors battery levels
40830 and warns the user through desktop notifications when their battery
40831 is getting low. You can also configure a command to be run when the
40832 battery level passes a point deemed ``dangerous''. This service is
40833 configured with the @code{home-batsignal-configuration} record.
40836 @deftp {Data Type} home-batsignal-configuration
40837 Data type representing the configuration for batsignal.
40840 @item @code{warning-level} (default: @code{15})
40841 The battery level to send a warning message at.
40843 @item @code{warning-message} (default: @code{#f})
40844 The message to send as a notification when the battery level reaches
40845 the @code{warning-level}. Setting to @code{#f} uses the default
40848 @item @code{critical-level} (default: @code{5})
40849 The battery level to send a critical message at.
40851 @item @code{critical-message} (default: @code{#f})
40852 The message to send as a notification when the battery level reaches
40853 the @code{critical-level}. Setting to @code{#f} uses the default
40856 @item @code{danger-level} (default: @code{2})
40857 The battery level to run the @code{danger-command} at.
40859 @item @code{danger-command} (default: @code{#f})
40860 The command to run when the battery level reaches the @code{danger-level}.
40861 Setting to @code{#f} disables running the command entirely.
40863 @item @code{full-level} (default: @code{#f})
40864 The battery level to send a full message at. Setting to @code{#f}
40865 disables sending the full message entirely.
40867 @item @code{full-message} (default: @code{#f})
40868 The message to send as a notification when the battery level reaches
40869 the @code{full-level}. Setting to @code{#f} uses the default message.
40871 @item @code{batteries} (default: @code{'()})
40872 The batteries to monitor. Setting to @code{'()} tries to find batteries
40875 @item @code{poll-delay} (default: @code{60})
40876 The time in seconds to wait before checking the batteries again.
40878 @item @code{icon} (default: @code{#f})
40879 A file-like object to use as the icon for battery notifications. Setting
40880 to @code{#f} disables notification icons entirely.
40882 @item @code{notifications?} (default: @code{#t})
40883 Whether to send any notifications.
40885 @item @code{notifications-expire?} (default: @code{#f})
40886 Whether notifications sent expire after a time.
40888 @item @code{notification-command} (default: @code{#f})
40889 Command to use to send messages. Setting to @code{#f} sends a notification
40890 through @code{libnotify}.
40892 @item @code{ignore-missing?} (default: @code{#f})
40893 Whether to ignore missing battery errors.
40897 @node Shepherd Home Service
40898 @subsection Managing User Daemons
40900 @cindex shepherd services, for users
40901 The @code{(gnu home services shepherd)} module supports the definitions
40902 of per-user Shepherd services (@pxref{Introduction,,, shepherd, The GNU
40903 Shepherd Manual}). You extend @code{home-shepherd-service-type} with
40904 new services; Guix Home then takes care of starting the @code{shepherd}
40905 daemon for you when you log in, which in turns starts the services you
40908 @defvr {Scheme Variable} home-shepherd-service-type
40909 The service type for the userland Shepherd, which allows one to manage
40910 long-running processes or one-shot tasks. User's Shepherd is not an
40911 init process (PID 1), but almost all other information described in
40912 (@pxref{Shepherd Services}) is applicable here too.
40914 This is the service type that extensions target when they want to create
40915 shepherd services (@pxref{Service Types and Services}, for an example).
40916 Each extension must pass a list of @code{<shepherd-service>}. Its
40917 value must be a @code{home-shepherd-configuration}, as described below.
40920 @deftp {Data Type} home-shepherd-configuration
40921 This data type represents the Shepherd's configuration.
40924 @item shepherd (default: @code{shepherd})
40925 The Shepherd package to use.
40927 @item auto-start? (default: @code{#t})
40928 Whether or not to start Shepherd on first login.
40930 @item services (default: @code{'()})
40931 A list of @code{<shepherd-service>} to start.
40932 You should probably use the service extension
40933 mechanism instead (@pxref{Shepherd Services}).
40938 @subsection Secure Shell
40940 @cindex secure shell client, configuration
40941 @cindex SSH client, configuration
40942 The @uref{https://www.openssh.com, OpenSSH package} includes a client,
40943 the @command{ssh} command, that allows you to connect to remote machines
40944 using the @acronym{SSH, secure shell} protocol. With the @code{(gnu
40945 home services ssh)} module, you can set up OpenSSH so that it works in a
40946 predictable fashion, almost independently of state on the local machine.
40947 To do that, you instantiate @code{home-openssh-service-type} in your
40948 Home configuration, as explained below.
40950 @defvr {Scheme Variable} home-openssh-service-type
40951 This is the type of the service to set up the OpenSSH client. It takes
40952 care of several things:
40956 providing a @file{~/.ssh/config} file based on your configuration so
40957 that @command{ssh} knows about hosts you regularly connect to and their
40958 associated parameters;
40961 providing a @file{~/.ssh/authorized_keys}, which lists public keys that
40962 the local SSH server, @command{sshd}, may accept to connect to this user
40966 optionally providing a @file{~/.ssh/known_hosts} file so that @file{ssh}
40967 can authenticate hosts you connect to.
40970 Here is an example of a service and its configuration that you could add
40971 to the @code{services} field of your @code{home-environment}:
40974 (service home-openssh-service-type
40975 (home-openssh-configuration
40977 (list (openssh-host (name "ci.guix.gnu.org")
40979 (openssh-host (name "chbouib")
40980 (host-name "chbouib.example.org")
40981 (user "supercharlie")
40983 (authorized-keys (list (local-file "alice.pub")))))
40986 The example above lists two hosts and their parameters. For instance,
40987 running @command{ssh chbouib} will automatically connect to
40988 @code{chbouib.example.org} on port 10022, logging in as user
40989 @samp{supercharlie}. Further, it marks the public key in
40990 @file{alice.pub} as authorized for incoming connections.
40992 The value associated with a @code{home-openssh-service-type} instance
40993 must be a @code{home-openssh-configuration} record, as describe below.
40996 @deftp {Data Type} home-openssh-configuration
40997 This is the datatype representing the OpenSSH client and server
40998 configuration in one's home environment. It contains the following
41002 @item @code{hosts} (default: @code{'()})
41003 A list of @code{openssh-host} records specifying host names and
41004 associated connection parameters (see below). This host list goes into
41005 @file{~/.ssh/config}, which @command{ssh} reads at startup.
41007 @item @code{known-hosts} (default: @code{*unspecified*})
41008 This must be either:
41012 @code{*unspecified*}, in which case @code{home-openssh-service-type}
41013 leaves it up to @command{ssh} and to the user to maintain the list of
41014 known hosts at @file{~/.ssh/known_hosts}, or
41017 a list of file-like objects, in which case those are concatenated and
41018 emitted as @file{~/.ssh/known_hosts}.
41021 The @file{~/.ssh/known_hosts} contains a list of host name/host key
41022 pairs that allow @command{ssh} to authenticate hosts you connect to and
41023 to detect possible impersonation attacks. By default, @command{ssh}
41024 updates it in a @dfn{TOFU, trust-on-first-use} fashion, meaning that it
41025 records the host's key in that file the first time you connect to it.
41026 This behavior is preserved when @code{known-hosts} is set to
41027 @code{*unspecified*}.
41029 If you instead provide a list of host keys upfront in the
41030 @code{known-hosts} field, your configuration becomes self-contained and
41031 stateless: it can be replicated elsewhere or at another point in time.
41032 Preparing this list can be relatively tedious though, which is why
41033 @code{*unspecified*} is kept as a default.
41035 @item @code{authorized-keys} (default: @code{'()})
41036 This must be a list of file-like objects, each of which containing an
41037 SSH public key that should be authorized to connect to this machine.
41039 Concretely, these files are concatenated and made available as
41040 @file{~/.ssh/authorized_keys}. If an OpenSSH server, @command{sshd}, is
41041 running on this machine, then it @emph{may} take this file into account:
41042 this is what @command{sshd} does by default, but be aware that it can
41043 also be configured to ignore it.
41047 @c %start of fragment
41049 @deftp {Data Type} openssh-host
41050 Available @code{openssh-host} fields are:
41053 @item @code{name} (type: string)
41054 Name of this host declaration.
41056 @item @code{host-name} (type: maybe-string)
41057 Host name---e.g., @code{"foo.example.org"} or @code{"192.168.1.2"}.
41059 @item @code{address-family} (type: address-family)
41060 Address family to use when connecting to this host: one of
41061 @code{AF_INET} (for IPv4 only), @code{AF_INET6} (for IPv6 only), or
41062 @code{*unspecified*} (allowing any address family).
41064 @item @code{identity-file} (type: maybe-string)
41065 The identity file to use---e.g., @code{"/home/charlie/.ssh/id_ed25519"}.
41067 @item @code{port} (type: maybe-natural-number)
41068 TCP port number to connect to.
41070 @item @code{user} (type: maybe-string)
41071 User name on the remote host.
41073 @item @code{forward-x11?} (default: @code{#f}) (type: boolean)
41074 Whether to forward remote client connections to the local X11 graphical
41077 @item @code{forward-x11-trusted?} (default: @code{#f}) (type: boolean)
41078 Whether remote X11 clients have full access to the original X11
41081 @item @code{forward-agent?} (default: @code{#f}) (type: boolean)
41082 Whether the authentication agent (if any) is forwarded to the remote
41085 @item @code{compression?} (default: @code{#f}) (type: boolean)
41086 Whether to compress data in transit.
41088 @item @code{proxy-command} (type: maybe-string)
41089 The command to use to connect to the server. As an example, a command
41090 to connect via an HTTP proxy at 192.0.2.0 would be: @code{"nc -X connect
41091 -x 192.0.2.0:8080 %h %p"}.
41093 @item @code{host-key-algorithms} (type: maybe-string-list)
41094 The list of accepted host key algorithms---e.g.,
41095 @code{'("ssh-ed25519")}.
41097 @item @code{accepted-key-types} (type: maybe-string-list)
41098 The list of accepted user public key types.
41100 @item @code{extra-content} (default: @code{""}) (type: raw-configuration-string)
41101 Extra content appended as-is to this @code{Host} block in
41102 @file{~/.ssh/config}.
41109 @c %end of fragment
41112 @node Desktop Home Services
41113 @subsection Desktop Home Services
41115 The @code{(gnu home services desktop)} module provides services that you
41116 may find useful on ``desktop'' systems running a graphical user
41117 environment such as Xorg.
41119 @defvr {Scheme Variable} home-redshift-service-type
41120 This is the service type for @uref{https://github.com/jonls/redshift,
41121 Redshift}, a program that adjusts the display color temperature
41122 according to the time of day. Its associated value must be a
41123 @code{home-redshift-configuration} record, as shown below.
41125 A typical configuration, where we manually specify the latitude and
41126 longitude, might look like this:
41129 (service home-redshift-service-type
41130 (home-redshift-configuration
41131 (location-provider 'manual)
41132 (latitude 35.81) ;northern hemisphere
41133 (longitude -0.80))) ;west of Greenwich
41137 @deftp {Data Type} home-redshift-configuration
41138 Available @code{home-redshift-configuration} fields are:
41141 @item @code{redshift} (default: @code{redshift}) (type: file-like)
41142 Redshift package to use.
41144 @item @code{location-provider} (default: @code{geoclue2}) (type: symbol)
41145 Geolocation provider---@code{'manual} or @code{'geoclue2}. In the
41146 former case, you must also specify the @code{latitude} and
41147 @code{longitude} fields so Redshift can determine daytime at your place.
41148 In the latter case, the Geoclue system service must be running; it will
41149 be queried for location information.
41151 @item @code{adjustment-method} (default: @code{randr}) (type: symbol)
41152 Color adjustment method.
41154 @item @code{daytime-temperature} (default: @code{6500}) (type: integer)
41155 Daytime color temperature (kelvins).
41157 @item @code{nighttime-temperature} (default: @code{4500}) (type: integer)
41158 Nighttime color temperature (kelvins).
41160 @item @code{daytime-brightness} (type: maybe-inexact-number)
41161 Daytime screen brightness, between 0.1 and 1.0, or left unspecified.
41163 @item @code{nighttime-brightness} (type: maybe-inexact-number)
41164 Nighttime screen brightness, between 0.1 and 1.0, or left unspecified.
41166 @item @code{latitude} (type: maybe-inexact-number)
41167 Latitude, when @code{location-provider} is @code{'manual}.
41169 @item @code{longitude} (type: maybe-inexact-number)
41170 Longitude, when @code{location-provider} is @code{'manual}.
41172 @item @code{dawn-time} (type: maybe-string)
41173 Custom time for the transition from night to day in the
41174 morning---@code{"HH:MM"} format. When specified, solar elevation is not
41175 used to determine the daytime/nighttime period.
41177 @item @code{dusk-time} (type: maybe-string)
41178 Likewise, custom time for the transition from day to night in the
41181 @item @code{extra-content} (default: @code{""}) (type: raw-configuration-string)
41182 Extra content appended as-is to the Redshift configuration file. Run
41183 @command{man redshift} for more information about the configuration file
41190 @node Guix Home Services
41191 @subsection Guix Home Services
41193 The @code{(gnu home services guix)} module provides services for
41194 user-specific Guix configuration.
41196 @defvr {Scheme Variable} home-channels-service-type
41197 This is the service type for managing
41198 @file{$XDG_CONFIG_HOME/guix/channels.scm}, the file that controls the
41199 channels received on @command{guix pull} (@pxref{Channels}). Its
41200 associated value is a list of @code{channel} records, defined in the
41201 @code{(guix channels)} module.
41203 Generally, it is better to extend this service than to directly
41204 configure it, as its default value is the default guix channel(s)
41205 defined by @code{%default-channels}. If you configure this service
41206 directly, be sure to include a guix channel. @xref{Specifying
41207 Additional Channels} and @ref{Using a Custom Guix Channel} for more
41210 A typical extension for adding a channel might look like this:
41213 (simple-service 'variant-packages-service
41214 home-channels-service-type
41217 (name 'variant-packages)
41218 (url "https://example.org/variant-packages.git")))
41222 @node Invoking guix home
41223 @section Invoking @command{guix home}
41225 @cindex @command{guix home}
41227 Once you have written a home environment declaration (@pxref{Declaring
41228 the Home Environment,,,,}, it can be @dfn{instantiated} using the
41229 @command{guix home} command. The synopsis is:
41232 guix home @var{options}@dots{} @var{action} @var{file}
41235 @var{file} must be the name of a file containing a
41236 @code{home-environment} declaration. @var{action} specifies how the
41237 home environment is instantiated, but there are few auxiliary actions
41238 which don't instantiate it. Currently the following values are
41243 Display available home service type definitions that match the given
41244 regular expressions, sorted by relevance:
41247 @cindex shell-profile
41251 $ guix home search shell
41252 name: home-shell-profile
41253 location: gnu/home/services/shells.scm:100:2
41254 extends: home-files
41255 description: Create `~/.profile', which is used for environment initialization of POSIX compliant login shells.
41256 + This service type can be extended with a list of file-like objects.
41260 location: gnu/home/services/shells.scm:640:2
41261 extends: home-files home-profile
41262 description: Install and configure Fish, the friendly interactive shell.
41266 location: gnu/home/services/shells.scm:290:2
41267 extends: home-files home-profile
41268 description: Install and configure Zsh.
41272 location: gnu/home/services/shells.scm:508:2
41273 extends: home-files home-profile
41274 description: Install and configure GNU Bash.
41280 As for @command{guix search}, the result is written in
41281 @code{recutils} format, which makes it easy to filter the output
41282 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
41284 @cindex container, for @command{guix home}
41286 Spawn a shell in an isolated environment---a
41287 @dfn{container}---containing your home as specified by @var{file}.
41289 For example, this is how you would start an interactive shell in a
41290 container with your home:
41293 guix home container config.scm
41296 This is a throw-away container where you can lightheartedly fiddle with
41297 files; any changes made within the container, any process started---all
41298 this disappears as soon as you exit that shell.
41300 As with @command{guix shell}, several options control that container:
41305 Enable networking within the container (it is disabled by default).
41307 @item --expose=@var{source}[=@var{target}]
41308 @itemx --share=@var{source}[=@var{target}]
41309 As with @command{guix shell}, make directory @var{source} of the host
41310 system available as @var{target} inside the container---read-only if you
41311 pass @option{--expose}, and writable if you pass @option{--share}
41312 (@pxref{Invoking guix shell, @option{--expose} and @option{--share}}).
41315 Additionally, you can run a command in that container, instead of
41316 spawning an interactive shell. For instance, here is how you would
41317 check which Shepherd services are started in a throw-away home
41321 guix home container config.scm -- herd status
41324 The command to run in the container must come after @code{--} (double
41327 @cindex service type definition, editing
41328 @cindex editing, service type definition
41330 Edit or view the definition of the given Home service types.
41332 For example, the command below opens your editor, as specified by the
41333 @env{EDITOR} environment variable, on the definition of the
41334 @code{home-mcron} service type:
41337 guix home edit home-mcron
41341 Build the home environment described in @var{file}, and switch to it.
41342 Switching means that the activation script will be evaluated and (in
41343 basic scenario) symlinks to configuration files generated from
41344 @code{home-environment} declaration will be created in @file{~}. If the
41345 file with the same path already exists in home folder it will be moved
41346 to @file{~/@var{timestamp}-guix-home-legacy-configs-backup}, where @var{timestamp}
41347 is a current UNIX epoch time.
41350 It is highly recommended to run @command{guix pull} once before you run
41351 @command{guix home reconfigure} for the first time (@pxref{Invoking guix
41355 This effects all the configuration specified in @var{file}. The command
41356 starts Shepherd services specified in @var{file} that are not currently
41357 running; if a service is currently running, this command will arrange
41358 for it to be upgraded the next time it is stopped (e.g.@: by @code{herd
41359 stop @var{service}} or @code{herd restart @var{service}}).
41361 This command creates a new generation whose number is one greater than
41362 the current generation (as reported by @command{guix home
41363 list-generations}). If that generation already exists, it will be
41364 overwritten. This behavior mirrors that of @command{guix package}
41365 (@pxref{Invoking guix package}).
41367 @cindex provenance tracking, of the home environment
41368 Upon completion, the new home is deployed under @file{~/.guix-home}.
41369 This directory contains @dfn{provenance meta-data}: the list of channels
41370 in use (@pxref{Channels}) and @var{file} itself, when available. You
41371 can view the provenance information by running:
41377 This information is useful should you later want to inspect how this
41378 particular generation was built. In fact, assuming @var{file} is
41379 self-contained, you can later rebuild generation @var{n} of your
41380 home environment with:
41383 guix time-machine \
41384 -C /var/guix/profiles/per-user/@var{USER}/guix-home-@var{n}-link/channels.scm -- \
41386 /var/guix/profiles/per-user/@var{USER}/guix-home-@var{n}-link/configuration.scm
41390 You can think of it as some sort of built-in version control! Your
41391 home is not just a binary artifact: @emph{it carries its own source}.
41392 @c @xref{Service Reference, @code{provenance-service-type}}, for more
41393 @c information on provenance tracking.
41395 @c @footnote{This action (and the related actions
41396 @c @code{switch-generation} and @code{roll-back}) are usable after the
41397 @c home environment is initialized.}.
41399 @item switch-generation
41400 @cindex home generations
41401 Switch to an existing home generation. This action atomically switches
41402 the home profile to the specified home generation.
41404 The target generation can be specified explicitly by its generation
41405 number. For example, the following invocation would switch to home
41409 guix home switch-generation 7
41412 The target generation can also be specified relative to the current
41413 generation with the form @code{+N} or @code{-N}, where @code{+3} means
41414 ``3 generations ahead of the current generation,'' and @code{-1} means
41415 ``1 generation prior to the current generation.'' When specifying a
41416 negative value such as @code{-1}, you must precede it with @code{--} to
41417 prevent it from being parsed as an option. For example:
41420 guix home switch-generation -- -1
41423 This action will fail if the specified generation does not exist.
41426 @cindex rolling back
41427 Switch to the preceding home generation. This is the inverse
41428 of @command{reconfigure}, and it is exactly the same as invoking
41429 @command{switch-generation} with an argument of @code{-1}.
41431 @item delete-generations
41432 @cindex deleting home generations
41433 @cindex saving space
41434 Delete home generations, making them candidates for garbage collection
41435 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
41438 This works in the same way as @samp{guix package --delete-generations}
41439 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
41440 arguments, all home generations but the current one are deleted:
41443 guix home delete-generations
41446 You can also select the generations you want to delete. The example below
41447 deletes all the home generations that are more than two months old:
41450 guix home delete-generations 2m
41454 Build the derivation of the home environment, which includes all the
41455 configuration files and programs needed. This action does not actually
41459 Describe the current home generation: its file name, as well as
41460 provenance information when available.
41462 To show installed packages in the current home generation's profile, the
41463 @code{--list-installed} flag is provided, with the same syntax that is
41464 used in @command{guix package --list-installed} (@pxref{Invoking guix
41465 package}). For instance, the following command shows a table of all the
41466 packages with ``emacs'' in their name that are installed in the current
41467 home generation's profile:
41470 guix home describe --list-installed=emacs
41473 @item list-generations
41474 List a summary of each generation of the home environment available on
41475 disk, in a human-readable way. This is similar to the
41476 @option{--list-generations} option of @command{guix package}
41477 (@pxref{Invoking guix package}).
41479 Optionally, one can specify a pattern, with the same syntax that is used
41480 in @command{guix package --list-generations}, to restrict the list of
41481 generations displayed. For instance, the following command displays
41482 generations that are up to 10 days old:
41485 guix home list-generations 10d
41488 The @code{--list-installed} flag may also be specified, with the same
41489 syntax that is used in @command{guix home describe}. This may be
41490 helpful if trying to determine when a package was added to the home
41494 Generate a @dfn{home environment} from the packages in the default
41495 profile and configuration files found in the user's home directory. The
41496 configuration files will be copied to the specified directory, and a
41497 @file{home-configuration.scm} will be populated with the home
41498 environment. Note that not every home service that exists is supported
41499 (@pxref{Home Services}).
41502 $ guix home import ~/guix-config
41503 guix home: '/home/alice/guix-config' populated with all the Home configuration files
41507 And there's more! @command{guix home} also provides the following
41508 sub-commands to visualize how the services of your home environment
41509 relate to one another:
41512 @cindex service extension graph, of a home environment
41513 @item extension-graph
41514 Emit to standard output the @dfn{service extension graph} of the home
41515 environment defined in @var{file} (@pxref{Service Composition}, for more
41516 information on service extensions). By default the output is in
41517 Dot/Graphviz format, but you can choose a different format with
41518 @option{--graph-backend}, as with @command{guix graph} (@pxref{Invoking
41519 guix graph, @option{--backend}}):
41524 guix home extension-graph @var{file} | xdot -
41527 shows the extension relations among services.
41529 @cindex Shepherd dependency graph, for a home environment
41530 @item shepherd-graph
41531 Emit to standard output the @dfn{dependency graph} of shepherd services
41532 of the home environment defined in @var{file}. @xref{Shepherd
41533 Services}, for more information and for an example graph.
41535 Again, the default output format is Dot/Graphviz, but you can pass
41536 @option{--graph-backend} to select a different one.
41539 @var{options} can contain any of the common build options (@pxref{Common
41540 Build Options}). In addition, @var{options} can contain one of the
41545 @item --expression=@var{expr}
41546 @itemx -e @var{expr}
41547 Consider the home-environment @var{expr} evaluates to.
41548 This is an alternative to specifying a file which evaluates to a home
41551 @item --allow-downgrades
41552 Instruct @command{guix home reconfigure} to allow system downgrades.
41554 Just like @command{guix system}, @command{guix home reconfigure}, by
41555 default, prevents you from downgrading your home to older or unrelated
41556 revisions compared to the channel revisions that were used to deploy
41557 it---those shown by @command{guix home describe}. Using
41558 @option{--allow-downgrades} allows you to bypass that check, at the risk
41559 of downgrading your home---be careful!
41563 @node Documentation
41564 @chapter Documentation
41566 @cindex documentation, searching for
41567 @cindex searching for documentation
41568 @cindex Info, documentation format
41570 @cindex manual pages
41571 In most cases packages installed with Guix come with documentation.
41572 There are two main documentation formats: ``Info'', a browsable
41573 hypertext format used for GNU software, and ``manual pages'' (or ``man
41574 pages''), the linear documentation format traditionally found on Unix.
41575 Info manuals are accessed with the @command{info} command or with Emacs,
41576 and man pages are accessed using @command{man}.
41578 You can look for documentation of software installed on your system by
41579 keyword. For example, the following command searches for information
41580 about ``TLS'' in Info manuals:
41584 "(emacs)Network Security" -- STARTTLS
41585 "(emacs)Network Security" -- TLS
41586 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
41587 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
41592 The command below searches for the same keyword in man
41593 pages@footnote{The database searched by @command{man -k} is only created
41594 in profiles that contain the @code{man-db} package.}:
41598 SSL (7) - OpenSSL SSL/TLS library
41599 certtool (1) - GnuTLS certificate tool
41603 These searches are purely local to your computer so you have the
41604 guarantee that documentation you find corresponds to what you have
41605 actually installed, you can access it off-line, and your privacy is
41608 Once you have these results, you can view the relevant documentation by
41612 $ info "(gnutls)Core TLS API"
41622 Info manuals contain sections and indices as well as hyperlinks like
41623 those found in Web pages. The @command{info} reader (@pxref{Top, Info
41624 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
41625 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
41626 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
41627 Introduction}, for an introduction to Info navigation.
41632 The packages and systems built by Guix are intended, like most computer
41633 programs, to run on a CPU with a specific instruction set, and under a
41634 specific operating system. Those programs are often also targeting a
41635 specific kernel and system library. Those constraints are captured by
41636 Guix in @code{platform} records.
41639 * platform Reference:: Detail of platform declarations.
41640 * Supported Platforms:: Description of the supported platforms.
41643 @node platform Reference
41644 @section @code{platform} Reference
41646 The @code{platform} data type describes a @dfn{platform}: an
41647 @acronym{ISA, instruction set architecture}, combined with an operating
41648 system and possibly additional system-wide settings such as the
41649 @acronym{ABI, application binary interface}.
41651 @deftp {Data Type} platform
41652 This is the data type representing a platform.
41655 @item @code{target}
41656 This field specifies the platform's GNU triplet as a string
41657 (@pxref{Specifying Target Triplets, GNU configuration triplets,,
41658 autoconf, Autoconf}).
41660 @item @code{system}
41661 This string is the system type as it is known to Guix and passed,
41662 for instance, to the @option{--system} option of most commands.
41664 It usually has the form @code{"@var{cpu}-@var{kernel}"}, where
41665 @var{cpu} is the target CPU and @var{kernel} the target operating
41668 It can be for instance @code{"aarch64-linux"} or @code{"armhf-linux"}.
41669 You will encounter system types when you perform native builds
41670 (@pxref{Native Builds}).
41672 @item @code{linux-architecture} (default: @code{#false})
41673 This optional string field is only relevant if the kernel is Linux. In
41674 that case, it corresponds to the ARCH variable used when building Linux,
41675 @code{"mips"} for instance.
41677 @item @code{glibc-dynamic-linker}
41678 This field is the name of the GNU C Library dynamic linker for the
41679 corresponding system, as a string. It can be
41680 @code{"/lib/ld-linux-armhf.so.3"}.
41685 @node Supported Platforms
41686 @section Supported Platforms
41688 The @code{(guix platforms @dots{})} modules export the following
41689 variables, each of which is bound to a @code{platform} record.
41691 @defvr {Scheme Variable} armv7-linux
41692 Platform targeting ARM v7 CPU running GNU/Linux.
41695 @defvr {Scheme Variable} aarch64-linux
41696 Platform targeting ARM v8 CPU running GNU/Linux.
41699 @defvr {Scheme Variable} mips64-linux
41700 Platform targeting MIPS little-endian 64-bit CPU running GNU/Linux.
41703 @defvr {Scheme Variable} powerpc-linux
41704 Platform targeting PowerPC big-endian 32-bit CPU running GNU/Linux.
41707 @defvr {Scheme Variable} powerpc64le-linux
41708 Platform targeting PowerPC little-endian 64-bit CPU running GNU/Linux.
41711 @defvr {Scheme Variable} riscv64-linux
41712 Platform targeting RISC-V 64-bit CPU running GNU/Linux.
41715 @defvr {Scheme Variable} i686-linux
41716 Platform targeting x86 CPU running GNU/Linux.
41719 @defvr {Scheme Variable} x86_64-linux
41720 Platform targeting x86 64-bit CPU running GNU/Linux.
41723 @defvr {Scheme Variable} i686-mingw
41724 Platform targeting x86 CPU running Windows, with run-time support from
41728 @defvr {Scheme Variable} x86_64-mingw
41729 Platform targeting x86 64-bit CPU running Windows, with run-time support
41733 @defvr {Scheme Variable} i586-gnu
41734 Platform targeting x86 CPU running GNU/Hurd (also referred to as
41738 @node System Images
41739 @chapter Creating System Images
41741 @cindex system images
41742 When it comes to installing Guix System for the first time on a new
41743 machine, you can basically proceed in three different ways. The first
41744 one is to use an existing operating system on the machine to run the
41745 @command{guix system init} command (@pxref{Invoking guix system}). The
41746 second one, is to produce an installation image (@pxref{Building the
41747 Installation Image}). This is a bootable system which role is to
41748 eventually run @command{guix system init}. Finally, the third option
41749 would be to produce an image that is a direct instantiation of the
41750 system you wish to run. That image can then be copied on a bootable
41751 device such as an USB drive or a memory card. The target machine would
41752 then directly boot from it, without any kind of installation procedure.
41754 The @command{guix system image} command is able to turn an operating
41755 system definition into a bootable image. This command supports
41756 different image types, such as @code{efi-raw}, @code{iso9660} and
41757 @code{docker}. Any modern @code{x86_64} machine will probably be able
41758 to boot from an @code{iso9660} image. However, there are a few machines
41759 out there that require specific image types. Those machines, in general
41760 using @code{ARM} processors, may expect specific partitions at specific
41763 This chapter explains how to define customized system images and how to
41764 turn them into actual bootable images.
41767 * image Reference:: Detail of image declarations.
41768 * Instantiate an Image:: How to instantiate an image record.
41769 * image-type Reference:: Detail of image types declaration.
41770 * Image Modules:: Definition of image modules.
41773 @node image Reference
41774 @section @code{image} Reference
41776 The @code{image} record, described right after, allows you to define a
41777 customized bootable system image.
41779 @deftp {Data Type} image
41780 This is the data type representing a system image.
41783 @item @code{name} (default: @code{#false})
41784 The image name as a symbol, @code{'my-iso9660} for instance. The name
41785 is optional and it defaults to @code{#false}.
41787 @item @code{format}
41788 The image format as a symbol. The following formats are supported:
41791 @item @code{disk-image}, a raw disk image composed of one or multiple
41794 @item @code{compressed-qcow2}, a compressed qcow2 image composed of
41795 one or multiple partitions.
41797 @item @code{docker}, a Docker image.
41799 @item @code{iso9660}, an ISO-9660 image.
41801 @item @code{tarball}, a tar.gz image archive.
41803 @item @code{wsl2}, a WSL2 image.
41807 @item @code{platform} (default: @code{#false})
41808 The @code{platform} record the image is targeting (@pxref{Platforms}),
41809 @code{aarch64-linux} for instance. By default, this field is set to
41810 @code{#false} and the image will target the host platform.
41812 @item @code{size} (default: @code{'guess})
41813 The image size in bytes or @code{'guess}. The @code{'guess} symbol,
41814 which is the default, means that the image size will be inferred based
41815 on the image content.
41817 @item @code{operating-system}
41818 The image's @code{operating-system} record that is instanciated.
41820 @item @code{partition-table-type} (default: @code{'mbr})
41821 The image partition table type as a symbol. Possible values are
41822 @code{'mbr} and @code{'gpt}. It default to @code{'mbr}.
41824 @item @code{partitions} (default: @code{'()})
41825 The image partitions as a list of @code{partition} records
41826 (@pxref{partition Reference}).
41828 @item @code{compression?} (default: @code{#true})
41829 Whether the image content should be compressed, as a boolean. It
41830 defaults to @code{#true} and only applies to @code{'iso9660} image
41833 @item @code{volatile-root?} (default: @code{#true})
41834 Whether the image root partition should be made volatile, as a boolean.
41836 This is achieved by using a RAM backed file system (overlayfs) that is
41837 mounted on top of the root partition by the initrd. It defaults to
41838 @code{#true}. When set to @code{#false}, the image root partition is
41839 mounted as read-write partition by the initrd.
41841 @item @code{shared-store?} (default: @code{#false})
41842 Whether the image's store should be shared with the host system, as a
41843 boolean. This can be useful when creating images dedicated to virtual
41844 machines. When set to @code{#false}, which is the default, the image's
41845 @code{operating-system} closure is copied to the image. Otherwise, when
41846 set to @code{#true}, it is assumed that the host store will be made
41847 available at boot, using a @code{9p} mount for instance.
41849 @item @code{shared-network?} (default: @code{#false})
41850 Whether to use the host network interfaces within the image, as a
41851 boolean. This is only used for the @code{'docker} image format. It
41852 defaults to @code{#false}.
41854 @item @code{substitutable?} (default: @code{#true})
41855 Whether the image derivation should be substitutable, as a boolean. It
41856 defaults to @code{true}.
41861 @node partition Reference
41862 @subsection @code{partition} Reference
41864 In @code{image} record may contain some partitions.
41866 @deftp {Data Type} partition
41867 This is the data type representing an image partition.
41870 @item @code{size} (default: @code{'guess})
41871 The partition size in bytes or @code{'guess}. The @code{'guess} symbol,
41872 which is the default, means that the partition size will be inferred
41873 based on the partition content.
41875 @item @code{offset} (default: @code{0})
41876 The partition's start offset in bytes, relative to the image start or
41877 the previous partition end. It defaults to @code{0} which means that
41878 there is no offset applied.
41880 @item @code{file-system} (default: @code{"ext4"})
41881 The partition file system as a string, defaulting to @code{"ext4"}. The
41882 supported values are @code{"vfat"}, @code{"fat16"}, @code{"fat32"} and
41885 @item @code{file-system-options} (default: @code{'()})
41886 The partition file system creation options that should be passed to the
41887 partition creation tool, as a list of strings. This is only supported
41888 when creating @code{"ext4"} partitions.
41890 See the @code{"extended-options"} man page section of the
41891 @code{"mke2fs"} tool for a more complete reference.
41894 The partition label as a mandatory string, @code{"my-root"} for
41897 @item @code{uuid} (default: @code{#false})
41898 The partition UUID as an @code{uuid} record (@pxref{File Systems}). By
41899 default it is @code{#false}, which means that the partition creation
41900 tool will attribute a random UUID to the partition.
41902 @item @code{flags} (default: @code{'()})
41903 The partition flags as a list of symbols. Possible values are
41904 @code{'boot} and @code{'esp}. The @code{'boot} flags should be set if
41905 you want to boot from this partition. Exactly one partition should have
41906 this flag set, usually the root one. The @code{'esp} flag identifies a
41907 UEFI System Partition.
41909 @item @code{initializer} (default: @code{#false})
41910 The partition initializer procedure as a gexp. This procedure is called
41911 to populate a partition. If no initializer is passed, the
41912 @code{initialize-root-partition} procedure from the @code{(gnu build
41913 image)} module is used.
41918 @node Instantiate an Image
41919 @section Instantiate an Image
41921 Let's say you would like to create an MBR image with three distinct
41925 @item The @acronym{ESP, EFI System Partition}, a partition of
41926 40@tie{}MiB at offset 1024@tie{}KiB with a vfat file system.
41928 @item an ext4 partition of 50@tie{}MiB data file, and labeled ``data''.
41930 @item an ext4 bootable partition containing the @code{%simple-os}
41934 You would then write the following image definition in a
41935 @code{my-image.scm} file for instance.
41944 (define MiB (expt 2 20))
41947 (format 'disk-image)
41948 (operating-system %simple-os)
41953 (offset (* 1024 1024))
41955 (file-system "vfat")
41957 (initializer (gexp initialize-efi-partition)))
41961 (file-system "ext4")
41962 (initializer #~(lambda* (root . rest)
41964 (call-with-output-file
41965 (string-append root "/data")
41967 (format port "my-data"))))))
41971 (file-system "ext4")
41973 (initializer (gexp initialize-root-partition))))))
41976 Note that the first and third partitions use generic initializers
41977 procedures, initialize-efi-partition and initialize-root-partition
41978 respectively. The initialize-efi-partition installs a GRUB EFI loader
41979 that is loading the GRUB bootloader located in the root partition. The
41980 initialize-root-partition instantiates a complete system as defined by
41981 the @code{%simple-os} operating-system.
41986 guix system image my-image.scm
41989 to instantiate the @code{image} definition. That produces a disk image
41990 which has the expected structure:
41993 $ parted $(guix system image my-image.scm) print
41996 Disk /gnu/store/yhylv1bp5b2ypb97pd3bbhz6jk5nbhxw-disk-image: 1714MB
41997 Sector size (logical/physical): 512B/512B
41998 Partition Table: msdos
42001 Number Start End Size Type File system Flags
42002 1 1049kB 43.0MB 41.9MB primary fat16 esp
42003 2 43.0MB 95.4MB 52.4MB primary ext4
42004 3 95.4MB 1714MB 1619MB primary ext4 boot
42007 The size of the @code{boot} partition has been inferred to @code{1619MB}
42008 so that it is large enough to host the @code{%simple-os}
42011 You can also use existing @code{image} record definitions and inherit
42012 from them to simplify the @code{image} definition. The @code{(gnu
42013 system image)} module provides the following @code{image} definition
42016 @defvr {Scheme Variable} efi-disk-image
42017 A MBR disk-image composed of two partitions: a 64 bits ESP partition and
42018 a ROOT boot partition. This image can be used on most @code{x86_64} and
42019 @code{i686} machines, supporting BIOS or UEFI booting.
42022 @defvr {Scheme Variable} efi32-disk-image
42023 Same as @code{efi-disk-image} but with a 32 bits EFI partition.
42026 @defvr {Scheme Variable} iso9660-image
42027 An ISO-9660 image composed of a single bootable partition. This image
42028 can also be used on most @code{x86_64} and @code{i686} machines.
42031 @defvr {Scheme Variable} docker-image
42032 A Docker image that can be used to spawn a Docker container.
42035 Using the @code{efi-disk-image} we can simplify our previous
42036 @code{image} declaration this way:
42046 (define MiB (expt 2 20))
42052 (file-system "ext4")
42053 (initializer #~(lambda* (root . rest)
42055 (call-with-output-file
42056 (string-append root "/data")
42058 (format port "my-data")))))))
42061 (inherit efi-disk-image)
42062 (operating-system %simple-os)
42064 (match (image-partitions efi-disk-image)
42066 (list esp data root)))))
42069 This will give the exact same @code{image} instantiation but the
42070 @code{image} declaration is simpler.
42072 @node image-type Reference
42073 @section image-type Reference
42075 The @command{guix system image} command can, as we saw above, take a
42076 file containing an @code{image} declaration as argument and produce an
42077 actual disk image from it. The same command can also handle a file
42078 containing an @code{operating-system} declaration as argument. In that
42079 case, how is the @code{operating-system} turned into an image?
42081 That's where the @code{image-type} record intervenes. This record
42082 defines how to transform an @code{operating-system} record into an
42083 @code{image} record.
42085 @deftp {Data Type} image-type
42086 This is the data type representing an image-type.
42090 The image-type name as a mandatory symbol, @code{'efi32-raw} for
42093 @item @code{constructor}
42094 The image-type constructor, as a mandatory procedure that takes an
42095 @code{operating-system} record as argument and returns an @code{image}
42101 There are several @code{image-type} records provided by the @code{(gnu
42102 system image)} and the @code{(gnu system images @dots{})} modules.
42104 @defvr {Scheme Variable} efi-raw-image-type
42105 Build an image based on the @code{efi-disk-image} image.
42108 @defvr {Scheme Variable} efi32-raw-image-type
42109 Build an image based on the @code{efi32-disk-image} image.
42112 @defvr {Scheme Variable} qcow2-image-type
42113 Build an image based on the @code{efi-disk-image} image but with the
42114 @code{compressed-qcow2} image format.
42117 @defvr {Scheme Variable} iso-image-type
42118 Build a compressed image based on the @code{iso9660-image} image.
42121 @defvr {Scheme Variable} uncompressed-iso-image-type
42122 Build an image based on the @code{iso9660-image} image but with the
42123 @code{compression?} field set to @code{#false}.
42126 @defvr {Scheme Variable} docker-image-type
42127 Build an image based on the @code{docker-image} image.
42130 @defvr {Scheme Variable} raw-with-offset-image-type
42131 Build an MBR image with a single partition starting at a @code{1024KiB}
42132 offset. This is useful to leave some room to install a bootloader in
42136 @defvr {Scheme Variable} pinebook-pro-image-type
42137 Build an image that is targeting the Pinebook Pro machine. The MBR
42138 image contains a single partition starting at a @code{9MiB} offset. The
42139 @code{u-boot-pinebook-pro-rk3399-bootloader} bootloader will be
42140 installed in this gap.
42143 @defvr {Scheme Variable} rock64-image-type
42144 Build an image that is targeting the Rock64 machine. The MBR image
42145 contains a single partition starting at a @code{16MiB} offset. The
42146 @code{u-boot-rock64-rk3328-bootloader} bootloader will be installed in
42150 @defvr {Scheme Variable} novena-image-type
42151 Build an image that is targeting the Novena machine. It has the same
42152 characteristics as @code{raw-with-offset-image-type}.
42155 @defvr {Scheme Variable} pine64-image-type
42156 Build an image that is targeting the Pine64 machine. It has the same
42157 characteristics as @code{raw-with-offset-image-type}.
42160 @defvr {Scheme Variable} hurd-image-type
42161 Build an image that is targeting a @code{i386} machine running the Hurd
42162 kernel. The MBR image contains a single ext2 partitions with specific
42163 @code{file-system-options} flags.
42166 @defvr {Scheme Variable} hurd-qcow2-image-type
42167 Build an image similar to the one built by the @code{hurd-image-type}
42168 but with the @code{format} set to @code{'compressed-qcow2}.
42171 @defvr {Scheme Variable} wsl2-image-type
42172 Build an image for the @acronym{WSL2, Windows Subsystem for Linux 2}.
42173 It can be imported by running:
42176 wsl --import Guix ./guix ./wsl2-image.tar.gz
42182 So, if we get back to the @code{guix system image} command taking an
42183 @code{operating-system} declaration as argument. By default, the
42184 @code{efi-raw-image-type} is used to turn the provided
42185 @code{operating-system} into an actual bootable image.
42187 To use a different @code{image-type}, the @code{--image-type} option can
42188 be used. The @code{--list-image-types} option will list all the
42189 supported image types. It turns out to be a textual listing of all the
42190 @code{image-types} variables described just above (@pxref{Invoking guix
42193 @node Image Modules
42194 @section Image Modules
42196 Let's take the example of the Pine64, an ARM based machine. To be able
42197 to produce an image targeting this board, we need the following
42201 @item An @code{operating-system} record containing at least
42202 an appropriate kernel (@code{linux-libre-arm64-generic}) and bootloader
42203 @code{u-boot-pine64-lts-bootloader}) for the Pine64.
42205 @item Possibly, an @code{image-type} record providing a way to
42206 turn an @code{operating-system} record to an @code{image} record
42207 suitable for the Pine64.
42209 @item An actual @code{image} that can be instantiated with the
42210 @command{guix system image} command.
42214 The @code{(gnu system images pine64)} module provides all those
42215 elements: @code{pine64-barebones-os}, @code{pine64-image-type} and
42216 @code{pine64-barebones-raw-image} respectively.
42218 The module returns the @code{pine64-barebones-raw-image} in order for
42219 users to be able to run:
42222 guix system image gnu/system/images/pine64.scm
42225 Now, thanks to the @code{pine64-image-type} record declaring the
42226 @code{'pine64-raw} @code{image-type}, one could also prepare a
42227 @code{my-pine.scm} file with the following content:
42230 (use-modules (gnu system images pine64))
42232 (inherit pine64-barebones-os)
42233 (timezone "Europe/Athens"))
42236 to customize the @code{pine64-barebones-os}, and run:
42239 $ guix system image --image-type=pine64-raw my-pine.scm
42242 Note that there are other modules in the @code{gnu/system/images}
42243 directory targeting @code{Novena}, @code{Pine64}, @code{PinebookPro} and
42244 @code{Rock64} machines.
42246 @node Installing Debugging Files
42247 @chapter Installing Debugging Files
42249 @cindex debugging files
42250 Program binaries, as produced by the GCC compilers for instance, are
42251 typically written in the ELF format, with a section containing
42252 @dfn{debugging information}. Debugging information is what allows the
42253 debugger, GDB, to map binary code to source code; it is required to
42254 debug a compiled program in good conditions.
42256 This chapter explains how to use separate debug info when packages
42257 provide it, and how to rebuild packages with debug info when it's
42261 * Separate Debug Info:: Installing 'debug' outputs.
42262 * Rebuilding Debug Info:: Building missing debug info.
42265 @node Separate Debug Info
42266 @section Separate Debug Info
42268 The problem with debugging information is that is takes up a fair amount
42269 of disk space. For example, debugging information for the GNU C Library
42270 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
42271 debugging info of all the installed programs is usually not an option.
42272 Yet, space savings should not come at the cost of an impediment to
42273 debugging---especially in the GNU system, which should make it easier
42274 for users to exert their computing freedom (@pxref{GNU Distribution}).
42276 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
42277 mechanism that allows users to get the best of both worlds: debugging
42278 information can be stripped from the binaries and stored in separate
42279 files. GDB is then able to load debugging information from those files,
42280 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
42283 The GNU distribution takes advantage of this by storing debugging
42284 information in the @code{lib/debug} sub-directory of a separate package
42285 output unimaginatively called @code{debug} (@pxref{Packages with
42286 Multiple Outputs}). Users can choose to install the @code{debug} output
42287 of a package when they need it. For instance, the following command
42288 installs the debugging information for the GNU C Library and for GNU
42292 guix install glibc:debug guile:debug
42295 GDB must then be told to look for debug files in the user's profile, by
42296 setting the @code{debug-file-directory} variable (consider setting it
42297 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
42301 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
42304 From there on, GDB will pick up debugging information from the
42305 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
42307 Below is an alternative GDB script which is useful when working with
42308 other profiles. It takes advantage of the optional Guile integration in
42309 GDB. This snippet is included by default on Guix System in the
42310 @file{~/.gdbinit} file.
42314 (use-modules (gdb))
42315 (execute (string-append "set debug-file-directory "
42316 (or (getenv "GDB_DEBUG_FILE_DIRECTORY")
42317 "~/.guix-profile/lib/debug")))
42321 In addition, you will most likely want GDB to be able to show the source
42322 code being debugged. To do that, you will have to unpack the source
42323 code of the package of interest (obtained with @code{guix build
42324 --source}, @pxref{Invoking guix build}), and to point GDB to that source
42325 directory using the @code{directory} command (@pxref{Source Path,
42326 @code{directory},, gdb, Debugging with GDB}).
42328 @c XXX: keep me up-to-date
42329 The @code{debug} output mechanism in Guix is implemented by the
42330 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
42331 opt-in---debugging information is available only for the packages with
42332 definitions explicitly declaring a @code{debug} output. To check
42333 whether a package has a @code{debug} output, use @command{guix package
42334 --list-available} (@pxref{Invoking guix package}).
42336 Read on for how to deal with packages lacking a @code{debug} output.
42338 @node Rebuilding Debug Info
42339 @section Rebuilding Debug Info
42341 @cindex debugging info, rebuilding
42342 As we saw above, some packages, but not all, provide debugging info in a
42343 @code{debug} output. What can you do when debugging info is missing?
42344 The @option{--with-debug-info} option provides a solution to that: it
42345 allows you to rebuild the package(s) for which debugging info is
42346 missing---and only those---and to graft those onto the application
42347 you're debugging. Thus, while it's not as fast as installing a
42348 @code{debug} output, it is relatively inexpensive.
42350 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
42351 and would like to see what's going on in GLib, a library that's deep
42352 down in its dependency graph. As it turns out, GLib does not have a
42353 @code{debug} output and the backtrace GDB shows is all sadness:
42357 #0 0x00007ffff5f92190 in g_getenv ()
42358 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
42359 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
42360 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
42361 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
42362 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
42363 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
42367 To address that, you install Inkscape linked against a variant GLib that
42368 contains debug info:
42371 guix install inkscape --with-debug-info=glib
42374 This time, debugging will be a whole lot nicer:
42377 $ gdb --args sh -c 'exec inkscape'
42380 Function "g_getenv" not defined.
42381 Make breakpoint pending on future shared library load? (y or [n]) y
42382 Breakpoint 1 (g_getenv) pending.
42384 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
42387 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
42388 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
42389 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
42390 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
42391 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
42397 Note that there can be packages for which @option{--with-debug-info}
42398 will not have the desired effect. @xref{Package Transformation Options,
42399 @option{--with-debug-info}}, for more information.
42401 @node Using TeX and LaTeX
42402 @chapter Using @TeX{} and @LaTeX{}
42404 @cindex @TeX{} packages
42405 @cindex @LaTeX{} packages
42406 Guix provides packages for the @TeX{}, @LaTeX{}, ConTeXt, LuaTeX, and
42407 related typesetting systems, taken from the
42408 @uref{https://www.tug.org/texlive/, @TeX{} Live distribution}. However,
42409 because @TeX{} Live is so huge and because finding your way in this maze
42410 is tricky, we thought that you, dear user, would welcome guidance on how
42411 to deploy the relevant packages so you can compile your @TeX{} and
42412 @LaTeX{} documents.
42414 @TeX{} Live currently comes in two flavors in Guix:
42418 The ``monolithic'' @code{texlive} package: it comes with @emph{every
42419 single @TeX{} Live package} (more than 7,000 of them), but it is huge
42420 (more than 4@tie{}GiB for a single package!).
42423 The ``modular'' @code{texlive-} packages: you install
42424 @code{texlive-base}, which provides core functionality and the main
42425 commands---@command{pdflatex}, @command{dvips}, @command{luatex},
42426 @command{mf}, etc.---together with individual packages that provide just
42427 the features you need---@code{texlive-listings} for the
42428 @code{listings} package, @code{texlive-hyperref} for @code{hyperref},
42429 @code{texlive-beamer} for Beamer, @code{texlive-pgf} for PGF/TikZ,
42433 We recommend using the modular package set because it is much less
42434 resource-hungry. To build your documents, you would use commands such
42438 guix shell texlive-base texlive-wrapfig \
42439 texlive-hyperref texlive-cm-super -- pdflatex doc.tex
42442 You can quickly end up with unreasonably long command lines though. The
42443 solution is to instead write a manifest, for example like this one:
42446 (specifications->manifest
42452 "texlive-microtype"
42453 "texlive-listings" "texlive-hyperref"
42458 ;; Additional fonts.
42459 "texlive-cm-super" "texlive-amsfonts"
42460 "texlive-times" "texlive-helvetic" "texlive-courier"))
42463 You can then pass it to any command with the @option{-m} option:
42466 guix shell -m manifest.scm -- pdflatex doc.tex
42469 @xref{Writing Manifests}, for more on
42470 manifests. In the future, we plan to provide packages for @TeX{} Live
42471 @dfn{collections}---``meta-packages'' such as @code{fontsrecommended},
42472 @code{humanities}, or @code{langarabic} that provide the set of packages
42473 needed in this particular domain. That will allow you to list fewer
42476 The main difficulty here is that using the modular package set forces
42477 you to select precisely the packages that you need. You can use
42478 @command{guix search}, but finding the right package can prove to be
42479 tedious. When a package is missing, @command{pdflatex} and similar
42480 commands fail with an obscure message along the lines of:
42483 doc.tex: File `tikz.sty' not found.
42484 doc.tex:7: Emergency stop.
42488 or, for a missing font:
42491 kpathsea: Running mktexmf phvr7t
42492 ! I can't find file `phvr7t'.
42495 How do you determine what the missing package is? In the first case,
42496 you'll find the answer by running:
42499 $ guix search texlive tikz
42505 In the second case, @command{guix search} turns up nothing. Instead,
42506 you can search the @TeX{} Live package database using the @command{tlmgr}
42510 $ guix shell texlive-base -- tlmgr info phvr7t
42511 tlmgr: cannot find package phvr7t, searching for other matches:
42513 Packages containing `phvr7t' in their title/description:
42515 Packages containing files matching `phvr7t':
42517 texmf-dist/fonts/tfm/adobe/helvetic/phvr7t.tfm
42518 texmf-dist/fonts/tfm/adobe/helvetic/phvr7tn.tfm
42519 texmf-dist/fonts/vf/adobe/helvetic/phvr7t.vf
42520 texmf-dist/fonts/vf/adobe/helvetic/phvr7tn.vf
42522 texmf-dist/tex4ht/ht-fonts/alias/adobe/helvetic/phvr7t.htf
42525 The file is available in the @TeX{} Live @code{helvetic} package, which is
42526 known in Guix as @code{texlive-helvetic}. Quite a ride, but we found
42529 There is one important limitation though: Guix currently provides a
42530 subset of the @TeX{} Live packages. If you stumble upon a missing
42531 package, you can try and import it (@pxref{Invoking guix import}):
42534 guix import texlive @var{package}
42537 Additional options include:
42542 Traverse the dependency graph of the given upstream package recursively
42543 and generate package expressions for all those packages that are not yet
42548 @TeX{} Live packaging is still very much work in progress, but you can
42549 help! @xref{Contributing}, for more information.
42552 @node Security Updates
42553 @chapter Security Updates
42555 @cindex security updates
42556 @cindex security vulnerabilities
42557 Occasionally, important security vulnerabilities are discovered in software
42558 packages and must be patched. Guix developers try hard to keep track of
42559 known vulnerabilities and to apply fixes as soon as possible in the
42560 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
42561 containing only security updates). The @command{guix lint} tool helps
42562 developers find out about vulnerable versions of software packages in the
42567 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
42568 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
42569 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
42573 @xref{Invoking guix lint}, for more information.
42575 Guix follows a functional
42576 package management discipline (@pxref{Introduction}), which implies
42577 that, when a package is changed, @emph{every package that depends on it}
42578 must be rebuilt. This can significantly slow down the deployment of
42579 fixes in core packages such as libc or Bash, since basically the whole
42580 distribution would need to be rebuilt. Using pre-built binaries helps
42581 (@pxref{Substitutes}), but deployment may still take more time than
42585 To address this, Guix implements @dfn{grafts}, a mechanism that allows
42586 for fast deployment of critical updates without the costs associated
42587 with a whole-distribution rebuild. The idea is to rebuild only the
42588 package that needs to be patched, and then to ``graft'' it onto packages
42589 explicitly installed by the user and that were previously referring to
42590 the original package. The cost of grafting is typically very low, and
42591 order of magnitudes lower than a full rebuild of the dependency chain.
42593 @cindex replacements of packages, for grafts
42594 For instance, suppose a security update needs to be applied to Bash.
42595 Guix developers will provide a package definition for the ``fixed''
42596 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
42597 Packages}). Then, the original package definition is augmented with a
42598 @code{replacement} field pointing to the package containing the bug fix:
42605 (replacement bash-fixed)))
42608 From there on, any package depending directly or indirectly on Bash---as
42609 reported by @command{guix gc --requisites} (@pxref{Invoking guix
42610 gc})---that is installed is automatically ``rewritten'' to refer to
42611 @code{bash-fixed} instead of @code{bash}. This grafting process takes
42612 time proportional to the size of the package, usually less than a
42613 minute for an ``average'' package on a recent machine. Grafting is
42614 recursive: when an indirect dependency requires grafting, then grafting
42615 ``propagates'' up to the package that the user is installing.
42617 Currently, the length of the name and version of the graft and that of
42618 the package it replaces (@code{bash-fixed} and @code{bash} in the example
42619 above) must be equal. This restriction mostly comes from the fact that
42620 grafting works by patching files, including binary files, directly.
42621 Other restrictions may apply: for instance, when adding a graft to a
42622 package providing a shared library, the original shared library and its
42623 replacement must have the same @code{SONAME} and be binary-compatible.
42625 The @option{--no-grafts} command-line option allows you to forcefully
42626 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
42630 guix build bash --no-grafts
42634 returns the store file name of the original Bash, whereas:
42641 returns the store file name of the ``fixed'', replacement Bash. This
42642 allows you to distinguish between the two variants of Bash.
42644 To verify which Bash your whole profile refers to, you can run
42645 (@pxref{Invoking guix gc}):
42648 guix gc -R $(readlink -f ~/.guix-profile) | grep bash
42652 @dots{} and compare the store file names that you get with those above.
42653 Likewise for a complete Guix system generation:
42656 guix gc -R $(guix system build my-config.scm) | grep bash
42659 Lastly, to check which Bash running processes are using, you can use the
42660 @command{lsof} command:
42663 lsof | grep /gnu/store/.*bash
42667 @node Bootstrapping
42668 @chapter Bootstrapping
42670 @c Adapted from the ELS 2013 paper.
42672 @cindex bootstrapping
42674 Bootstrapping in our context refers to how the distribution gets built
42675 ``from nothing''. Remember that the build environment of a derivation
42676 contains nothing but its declared inputs (@pxref{Introduction}). So
42677 there's an obvious chicken-and-egg problem: how does the first package
42678 get built? How does the first compiler get compiled?
42680 It is tempting to think of this question as one that only die-hard
42681 hackers may care about. However, while the answer to that question is
42682 technical in nature, its implications are wide-ranging. How the
42683 distribution is bootstrapped defines the extent to which we, as
42684 individuals and as a collective of users and hackers, can trust the
42685 software we run. It is a central concern from the standpoint of
42686 @emph{security} and from a @emph{user freedom} viewpoint.
42688 @cindex bootstrap binaries
42689 The GNU system is primarily made of C code, with libc at its core. The
42690 GNU build system itself assumes the availability of a Bourne shell and
42691 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
42692 `grep'. Furthermore, build programs---programs that run
42693 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
42694 (@pxref{Derivations}). Consequently, to be able to build anything at
42695 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
42696 Binutils, libc, and the other packages mentioned above---the
42697 @dfn{bootstrap binaries}.
42699 These bootstrap binaries are ``taken for granted'', though we can also
42700 re-create them if needed (@pxref{Preparing to Use the Bootstrap
42704 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
42705 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
42708 @node Reduced Binary Seed Bootstrap
42709 @section The Reduced Binary Seed Bootstrap
42711 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
42712 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
42713 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
42714 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
42715 ``taken for granted.''
42717 Taking the bootstrap binaries for granted means that we consider them to
42718 be a correct and trustworthy ``seed'' for building the complete system.
42719 Therein lies a problem: the combined size of these bootstrap binaries is
42720 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
42721 or even inspecting these is next to impossible.
42723 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
42724 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
42725 Source Bootstrap'' and while we are working towards that goal it would
42726 be hyperbole to use that term for what we do now.}.
42728 The Reduced Binary Seed bootstrap removes the most critical tools---from a
42729 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
42730 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
42731 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
42732 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
42734 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
42735 C Library are built from source. From here on the more traditional
42736 bootstrap process resumes. This approach has reduced the bootstrap
42737 binaries in size to about 145MB in Guix v1.1.
42739 The next step that Guix has taken is to replace the shell and all its
42740 utilities with implementations in Guile Scheme, the @emph{Scheme-only
42741 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
42742 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
42743 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
42744 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
42745 removed are now built from source.
42747 Building the GNU System from source is currently only possible by adding
42748 some historical GNU packages as intermediate steps@footnote{Packages
42749 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
42750 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
42751 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
42752 and GNU packages become more bootstrappable again (e.g., new releases of
42753 GNU Sed will also ship as gzipped tarballs again, as alternative to the
42754 hard to bootstrap @code{xz}-compression), this set of added packages can
42755 hopefully be reduced again.
42757 The graph below shows the resulting dependency graph for
42758 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
42759 traditional bootstrap of the rest of the Guix System.
42761 @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
42762 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
42764 The only significant binary bootstrap seeds that remain@footnote{
42765 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
42766 together with @code{mes}.} are a Scheme interpreter and a Scheme
42767 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
42768 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
42769 to get Guile running.}.
42771 This further reduction has brought down the size of the binary seed to
42772 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
42774 Work is ongoing to remove all binary blobs from our free software
42775 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
42776 is work to bring these bootstraps to the @code{arm-linux} and
42777 @code{aarch64-linux} architectures and to the Hurd.
42779 If you are interested, join us on @samp{#bootstrappable} on the Freenode
42780 IRC network or discuss on @email{bug-mes@@gnu.org} or
42781 @email{gash-devel@@nongnu.org}.
42783 @node Preparing to Use the Bootstrap Binaries
42784 @section Preparing to Use the Bootstrap Binaries
42786 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
42787 @c large image, it's hard to scroll. Oh well.
42788 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
42790 The figure above shows the very beginning of the dependency graph of the
42791 distribution, corresponding to the package definitions of the @code{(gnu
42792 packages bootstrap)} module. A similar figure can be generated with
42793 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
42796 guix graph -t derivation \
42797 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
42798 | dot -Tps > gcc.ps
42801 or, for the further Reduced Binary Seed bootstrap
42804 guix graph -t derivation \
42805 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
42806 | dot -Tps > mes.ps
42809 At this level of detail, things are
42810 slightly complex. First, Guile itself consists of an ELF executable,
42811 along with many source and compiled Scheme files that are dynamically
42812 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
42813 tarball shown in this graph. This tarball is part of Guix's ``source''
42814 distribution, and gets inserted into the store with @code{add-to-store}
42815 (@pxref{The Store}).
42817 But how do we write a derivation that unpacks this tarball and adds it
42818 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
42819 derivation---the first one that gets built---uses @code{bash} as its
42820 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
42821 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
42822 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
42823 the Guix source distribution, whose sole purpose is to allow the Guile
42824 tarball to be unpacked.
42826 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
42827 Guile that can be used to run subsequent build programs. Its first task
42828 is to download tarballs containing the other pre-built binaries---this
42829 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
42830 @code{ftp-client.scm} are used for this purpose. The
42831 @code{module-import.drv} derivations import those modules in a directory
42832 in the store, using the original layout. The
42833 @code{module-import-compiled.drv} derivations compile those modules, and
42834 write them in an output directory with the right layout. This
42835 corresponds to the @code{#:modules} argument of
42836 @code{build-expression->derivation} (@pxref{Derivations}).
42838 Finally, the various tarballs are unpacked by the derivations
42839 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
42840 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
42841 point we have a working C tool chain.
42843 @unnumberedsec Building the Build Tools
42845 Bootstrapping is complete when we have a full tool chain that does not
42846 depend on the pre-built bootstrap tools discussed above. This
42847 no-dependency requirement is verified by checking whether the files of
42848 the final tool chain contain references to the @file{/gnu/store}
42849 directories of the bootstrap inputs. The process that leads to this
42850 ``final'' tool chain is described by the package definitions found in
42851 the @code{(gnu packages commencement)} module.
42853 The @command{guix graph} command allows us to ``zoom out'' compared to
42854 the graph above, by looking at the level of package objects instead of
42855 individual derivations---remember that a package may translate to
42856 several derivations, typically one derivation to download its source,
42857 one to build the Guile modules it needs, and one to actually build the
42858 package from source. The command:
42861 guix graph -t bag \
42862 -e '(@@@@ (gnu packages commencement)
42863 glibc-final-with-bootstrap-bash)' | xdot -
42867 displays the dependency graph leading to the ``final'' C
42868 library@footnote{You may notice the @code{glibc-intermediate} label,
42869 suggesting that it is not @emph{quite} final, but as a good
42870 approximation, we will consider it final.}, depicted below.
42872 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
42874 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
42875 The first tool that gets built with the bootstrap binaries is
42876 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
42877 for all the following packages. From there Findutils and Diffutils get
42880 Then come the first-stage Binutils and GCC, built as pseudo cross
42881 tools---i.e., with @option{--target} equal to @option{--host}. They are
42882 used to build libc. Thanks to this cross-build trick, this libc is
42883 guaranteed not to hold any reference to the initial tool chain.
42885 From there the final Binutils and GCC (not shown above) are built. GCC
42886 uses @command{ld} from the final Binutils, and links programs against
42887 the just-built libc. This tool chain is used to build the other
42888 packages used by Guix and by the GNU Build System: Guile, Bash,
42891 And voilà! At this point we have the complete set of build tools that
42892 the GNU Build System expects. These are in the @code{%final-inputs}
42893 variable of the @code{(gnu packages commencement)} module, and are
42894 implicitly used by any package that uses @code{gnu-build-system}
42895 (@pxref{Build Systems, @code{gnu-build-system}}).
42898 @unnumberedsec Building the Bootstrap Binaries
42900 @cindex bootstrap binaries
42901 Because the final tool chain does not depend on the bootstrap binaries,
42902 those rarely need to be updated. Nevertheless, it is useful to have an
42903 automated way to produce them, should an update occur, and this is what
42904 the @code{(gnu packages make-bootstrap)} module provides.
42906 The following command builds the tarballs containing the bootstrap binaries
42907 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
42908 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
42909 and Guile, and a tarball containing a mixture of Coreutils and other basic
42910 command-line tools):
42913 guix build bootstrap-tarballs
42916 The generated tarballs are those that should be referred to in the
42917 @code{(gnu packages bootstrap)} module mentioned at the beginning of
42920 Still here? Then perhaps by now you've started to wonder: when do we
42921 reach a fixed point? That is an interesting question! The answer is
42922 unknown, but if you would like to investigate further (and have
42923 significant computational and storage resources to do so), then let us
42926 @unnumberedsec Reducing the Set of Bootstrap Binaries
42928 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
42929 binary code! Why is that a problem? It's a problem because these big chunks
42930 of binary code are practically non-auditable, which makes it hard to establish
42931 what source code produced them. Every unauditable binary also leaves us
42932 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
42933 paper @emph{Reflections on Trusting Trust}.
42935 This is mitigated by the fact that our bootstrap binaries were generated
42936 from an earlier Guix revision. Nevertheless it lacks the level of
42937 transparency that we get in the rest of the package dependency graph,
42938 where Guix always gives us a source-to-binary mapping. Thus, our goal
42939 is to reduce the set of bootstrap binaries to the bare minimum.
42941 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
42942 on-going projects to do that. One of these is about replacing the
42943 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
42944 of increasing complexity, which could be built from source starting from
42945 a simple and auditable assembler.
42947 Our first major achievement is the replacement of of GCC, the GNU C Library
42948 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
42949 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
42950 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
42951 bootstrapped yet and thus we inject them as binary seeds. We call this the
42952 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
42953 binaries! Also, it has eliminated the C compiler binary; i686-linux and
42954 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
42956 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
42957 also looking at any other bootstrap binaries. Your help is welcome!
42960 @chapter Porting to a New Platform
42962 As discussed above, the GNU distribution is self-contained, and
42963 self-containment is achieved by relying on pre-built ``bootstrap
42964 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
42965 operating system kernel, CPU architecture, and application binary
42966 interface (ABI). Thus, to port the distribution to a platform that is
42967 not yet supported, one must build those bootstrap binaries, and update
42968 the @code{(gnu packages bootstrap)} module to use them on that platform.
42970 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
42971 When everything goes well, and assuming the GNU tool chain supports the
42972 target platform, this can be as simple as running a command like this
42976 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
42979 For this to work, it is first required to register a new platform as
42980 defined in the @code{(guix platform)} module. A platform is making the
42981 connection between a GNU triplet (@pxref{Specifying Target Triplets, GNU
42982 configuration triplets,, autoconf, Autoconf}), the equivalent
42983 @var{system} in Nix notation, the name of the
42984 @var{glibc-dynamic-linker}, and the corresponding Linux architecture
42985 name if applicable (@pxref{Platforms}).
42987 Once the bootstrap tarball are built, the @code{(gnu packages
42988 bootstrap)} module needs to be updated to refer to these binaries on the
42989 target platform. That is, the hashes and URLs of the bootstrap tarballs
42990 for the new platform must be added alongside those of the currently
42991 supported platforms. The bootstrap Guile tarball is treated specially:
42992 it is expected to be available locally, and @file{gnu/local.mk} has
42993 rules to download it for the supported architectures; a rule for the new
42994 platform must be added as well.
42996 In practice, there may be some complications. First, it may be that the
42997 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
42998 above) is not recognized by all the GNU tools. Typically, glibc
42999 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
43000 configure flag (see @code{gcc.scm} for examples of how to handle this).
43001 Second, some of the required packages could fail to build for that
43002 platform. Lastly, the generated binaries could be broken for some
43005 @c *********************************************************************
43006 @include contributing.texi
43008 @c *********************************************************************
43009 @node Acknowledgments
43010 @chapter Acknowledgments
43012 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
43013 which was designed and
43014 implemented by Eelco Dolstra, with contributions from other people (see
43015 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
43016 management, and promoted unprecedented features, such as transactional
43017 package upgrades and rollbacks, per-user profiles, and referentially
43018 transparent build processes. Without this work, Guix would not exist.
43020 The Nix-based software distributions, Nixpkgs and NixOS, have also been
43021 an inspiration for Guix.
43023 GNU@tie{}Guix itself is a collective work with contributions from a
43024 number of people. See the @file{AUTHORS} file in Guix for more
43025 information on these fine people. The @file{THANKS} file lists people
43026 who have helped by reporting bugs, taking care of the infrastructure,
43027 providing artwork and themes, making suggestions, and more---thank you!
43030 @c *********************************************************************
43031 @node GNU Free Documentation License
43032 @appendix GNU Free Documentation License
43033 @cindex license, GNU Free Documentation License
43034 @include fdl-1.3.texi
43036 @c *********************************************************************
43037 @node Concept Index
43038 @unnumbered Concept Index
43041 @node Programming Index
43042 @unnumbered Programming Index
43043 @syncodeindex tp fn
43044 @syncodeindex vr fn
43049 @c Local Variables:
43050 @c ispell-local-dictionary: "american";