6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 27D586A4F8900854329FF09F1260E46482E63562
14 @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=127547
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER-1 ci.guix.gnu.org
21 @set SUBSTITUTE-SERVER-2 bordeaux.guix.gnu.org
22 @set SUBSTITUTE-URLS https://@value{SUBSTITUTE-SERVER-1} https://@value{SUBSTITUTE-SERVER-2}
25 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès@*
26 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
27 Copyright @copyright{} 2013 Nikita Karetnikov@*
28 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
29 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
30 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
31 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
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86 Copyright @copyright{} 2020 raingloom@*
87 Copyright @copyright{} 2020 Daniel Brooks@*
88 Copyright @copyright{} 2020 John Soo@*
89 Copyright @copyright{} 2020 Jonathan Brielmaier@*
90 Copyright @copyright{} 2020 Edgar Vincent@*
91 Copyright @copyright{} 2021 Maxime Devos@*
92 Copyright @copyright{} 2021 B. Wilson@*
93 Copyright @copyright{} 2021 Xinglu Chen@*
94 Copyright @copyright{} 2021 Raghav Gururajan@*
95 Copyright @copyright{} 2021 Domagoj Stolfa@*
96 Copyright @copyright{} 2021 Hui Lu@*
98 Permission is granted to copy, distribute and/or modify this document
99 under the terms of the GNU Free Documentation License, Version 1.3 or
100 any later version published by the Free Software Foundation; with no
101 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
102 copy of the license is included in the section entitled ``GNU Free
103 Documentation License''.
106 @dircategory System administration
108 * Guix: (guix). Manage installed software and system configuration.
109 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
110 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
111 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
112 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
113 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
116 @dircategory Software development
118 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
119 * guix build: (guix)Invoking guix build. Building packages.
120 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
124 @title GNU Guix Reference Manual
125 @subtitle Using the GNU Guix Functional Package Manager
126 @author The GNU Guix Developers
129 @vskip 0pt plus 1filll
130 Edition @value{EDITION} @*
138 @c *********************************************************************
142 This document describes GNU Guix version @value{VERSION}, a functional
143 package management tool written for the GNU system.
145 @c TRANSLATORS: You can replace the following paragraph with information on
146 @c how to join your own translation team and how to report issues with the
148 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
149 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
150 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
151 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
152 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
153 would like to translate it in your native language, consider joining
154 @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
155 Weblate} (@pxref{Translating Guix}).
158 * Introduction:: What is Guix about?
159 * Installation:: Installing Guix.
160 * System Installation:: Installing the whole operating system.
161 * Getting Started:: Your first steps.
162 * Package Management:: Package installation, upgrade, etc.
163 * Channels:: Customizing the package collection.
164 * Development:: Guix-aided software development.
165 * Programming Interface:: Using Guix in Scheme.
166 * Utilities:: Package management commands.
167 * System Configuration:: Configuring the operating system.
168 * Documentation:: Browsing software user manuals.
169 * Installing Debugging Files:: Feeding the debugger.
170 * Security Updates:: Deploying security fixes quickly.
171 * Bootstrapping:: GNU/Linux built from scratch.
172 * Porting:: Targeting another platform or kernel.
173 * Contributing:: Your help needed!
175 * Acknowledgments:: Thanks!
176 * GNU Free Documentation License:: The license of this manual.
177 * Concept Index:: Concepts.
178 * Programming Index:: Data types, functions, and variables.
181 --- The Detailed Node Listing ---
185 * Managing Software the Guix Way:: What's special.
186 * GNU Distribution:: The packages and tools.
190 * Binary Installation:: Getting Guix running in no time!
191 * Requirements:: Software needed to build and run Guix.
192 * Running the Test Suite:: Testing Guix.
193 * Setting Up the Daemon:: Preparing the build daemon's environment.
194 * Invoking guix-daemon:: Running the build daemon.
195 * Application Setup:: Application-specific setup.
196 * Upgrading Guix:: Upgrading Guix and its build daemon.
198 Setting Up the Daemon
200 * Build Environment Setup:: Preparing the isolated build environment.
201 * Daemon Offload Setup:: Offloading builds to remote machines.
202 * SELinux Support:: Using an SELinux policy for the daemon.
206 * Limitations:: What you can expect.
207 * Hardware Considerations:: Supported hardware.
208 * USB Stick and DVD Installation:: Preparing the installation medium.
209 * Preparing for Installation:: Networking, partitioning, etc.
210 * Guided Graphical Installation:: Easy graphical installation.
211 * Manual Installation:: Manual installation for wizards.
212 * After System Installation:: When installation succeeded.
213 * Installing Guix in a VM:: Guix System playground.
214 * Building the Installation Image:: How this comes to be.
218 * Keyboard Layout and Networking and Partitioning:: Initial setup.
219 * Proceeding with the Installation:: Installing.
223 * Features:: How Guix will make your life brighter.
224 * Invoking guix package:: Package installation, removal, etc.
225 * Substitutes:: Downloading pre-built binaries.
226 * Packages with Multiple Outputs:: Single source package, multiple outputs.
227 * Invoking guix gc:: Running the garbage collector.
228 * Invoking guix pull:: Fetching the latest Guix and distribution.
229 * Invoking guix time-machine:: Running an older revision of Guix.
230 * Inferiors:: Interacting with another revision of Guix.
231 * Invoking guix describe:: Display information about your Guix revision.
232 * Invoking guix archive:: Exporting and importing store files.
236 * Official Substitute Servers:: One particular source of substitutes.
237 * Substitute Server Authorization:: How to enable or disable substitutes.
238 * Getting Substitutes from Other Servers:: Substitute diversity.
239 * Substitute Authentication:: How Guix verifies substitutes.
240 * Proxy Settings:: How to get substitutes via proxy.
241 * Substitution Failure:: What happens when substitution fails.
242 * On Trusting Binaries:: How can you trust that binary blob?
246 * Specifying Additional Channels:: Extending the package collection.
247 * Using a Custom Guix Channel:: Using a customized Guix.
248 * Replicating Guix:: Running the @emph{exact same} Guix.
249 * Channel Authentication:: How Guix verifies what it fetches.
250 * Channels with Substitutes:: Using channels with available substitutes.
251 * Creating a Channel:: How to write your custom channel.
252 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
253 * Declaring Channel Dependencies:: How to depend on other channels.
254 * Specifying Channel Authorizations:: Defining channel authors authorizations.
255 * Primary URL:: Distinguishing mirror to original.
256 * Writing Channel News:: Communicating information to channel's users.
260 * Invoking guix environment:: Setting up development environments.
261 * Invoking guix pack:: Creating software bundles.
262 * The GCC toolchain:: Working with languages supported by GCC.
263 * Invoking guix git authenticate:: Authenticating Git repositories.
265 Programming Interface
267 * Package Modules:: Packages from the programmer's viewpoint.
268 * Defining Packages:: Defining new packages.
269 * Defining Package Variants:: Customizing packages.
270 * Build Systems:: Specifying how packages are built.
271 * Build Phases:: Phases of the build process of a package.
272 * Build Utilities:: Helpers for your package definitions and more.
273 * The Store:: Manipulating the package store.
274 * Derivations:: Low-level interface to package derivations.
275 * The Store Monad:: Purely functional interface to the store.
276 * G-Expressions:: Manipulating build expressions.
277 * Invoking guix repl:: Programming Guix in Guile.
281 * package Reference:: The package data type.
282 * origin Reference:: The origin data type.
286 * Invoking guix build:: Building packages from the command line.
287 * Invoking guix edit:: Editing package definitions.
288 * Invoking guix download:: Downloading a file and printing its hash.
289 * Invoking guix hash:: Computing the cryptographic hash of a file.
290 * Invoking guix import:: Importing package definitions.
291 * Invoking guix refresh:: Updating package definitions.
292 * Invoking guix lint:: Finding errors in package definitions.
293 * Invoking guix size:: Profiling disk usage.
294 * Invoking guix graph:: Visualizing the graph of packages.
295 * Invoking guix publish:: Sharing substitutes.
296 * Invoking guix challenge:: Challenging substitute servers.
297 * Invoking guix copy:: Copying to and from a remote store.
298 * Invoking guix container:: Process isolation.
299 * Invoking guix weather:: Assessing substitute availability.
300 * Invoking guix processes:: Listing client processes.
302 Invoking @command{guix build}
304 * Common Build Options:: Build options for most commands.
305 * Package Transformation Options:: Creating variants of packages.
306 * Additional Build Options:: Options specific to 'guix build'.
307 * Debugging Build Failures:: Real life packaging experience.
311 * Using the Configuration System:: Customizing your GNU system.
312 * operating-system Reference:: Detail of operating-system declarations.
313 * File Systems:: Configuring file system mounts.
314 * Mapped Devices:: Block device extra processing.
315 * User Accounts:: Specifying user accounts.
316 * Keyboard Layout:: How the system interprets key strokes.
317 * Locales:: Language and cultural convention settings.
318 * Services:: Specifying system services.
319 * Setuid Programs:: Programs running with root privileges.
320 * X.509 Certificates:: Authenticating HTTPS servers.
321 * Name Service Switch:: Configuring libc's name service switch.
322 * Initial RAM Disk:: Linux-Libre bootstrapping.
323 * Bootloader Configuration:: Configuring the boot loader.
324 * Invoking guix system:: Instantiating a system configuration.
325 * Invoking guix deploy:: Deploying a system configuration to a remote host.
326 * Running Guix in a VM:: How to run Guix System in a virtual machine.
327 * Defining Services:: Adding new service definitions.
331 * Base Services:: Essential system services.
332 * Scheduled Job Execution:: The mcron service.
333 * Log Rotation:: The rottlog service.
334 * Networking Services:: Network setup, SSH daemon, etc.
335 * Unattended Upgrades:: Automated system upgrades.
336 * X Window:: Graphical display.
337 * Printing Services:: Local and remote printer support.
338 * Desktop Services:: D-Bus and desktop services.
339 * Sound Services:: ALSA and Pulseaudio services.
340 * Database Services:: SQL databases, key-value stores, etc.
341 * Mail Services:: IMAP, POP3, SMTP, and all that.
342 * Messaging Services:: Messaging services.
343 * Telephony Services:: Telephony services.
344 * Monitoring Services:: Monitoring services.
345 * Kerberos Services:: Kerberos services.
346 * LDAP Services:: LDAP services.
347 * Web Services:: Web servers.
348 * Certificate Services:: TLS certificates via Let's Encrypt.
349 * DNS Services:: DNS daemons.
350 * VPN Services:: VPN daemons.
351 * Network File System:: NFS related services.
352 * Continuous Integration:: Cuirass and Laminar services.
353 * Power Management Services:: Extending battery life.
354 * Audio Services:: The MPD.
355 * Virtualization Services:: Virtualization services.
356 * Version Control Services:: Providing remote access to Git repositories.
357 * Game Services:: Game servers.
358 * PAM Mount Service:: Service to mount volumes when logging in.
359 * Guix Services:: Services relating specifically to Guix.
360 * Linux Services:: Services tied to the Linux kernel.
361 * Hurd Services:: Services specific for a Hurd System.
362 * Miscellaneous Services:: Other services.
366 * Service Composition:: The model for composing services.
367 * Service Types and Services:: Types and services.
368 * Service Reference:: API reference.
369 * Shepherd Services:: A particular type of service.
371 Installing Debugging Files
373 * Separate Debug Info:: Installing 'debug' outputs.
374 * Rebuilding Debug Info:: Building missing debug info.
378 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
379 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
384 @c *********************************************************************
386 @chapter Introduction
389 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
390 using the international phonetic alphabet (IPA).} is a package
391 management tool for and distribution of the GNU system.
392 Guix makes it easy for unprivileged
393 users to install, upgrade, or remove software packages, to roll back to a
394 previous package set, to build packages from source, and generally
395 assists with the creation and maintenance of software environments.
398 @cindex GuixSD, now Guix System
399 @cindex Guix System Distribution, now Guix System
400 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
401 complements the available tools without interference (@pxref{Installation}),
402 or you can use it as a standalone operating system distribution,
403 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
404 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
405 group everything under the ``Guix'' banner since, after all, Guix System is
406 readily available through the @command{guix system} command, even if you're
407 using a different distro underneath!}. @xref{GNU Distribution}.
410 * Managing Software the Guix Way:: What's special.
411 * GNU Distribution:: The packages and tools.
414 @node Managing Software the Guix Way
415 @section Managing Software the Guix Way
417 @cindex user interfaces
418 Guix provides a command-line package management interface
419 (@pxref{Package Management}), tools to help with software development
420 (@pxref{Development}), command-line utilities for more advanced usage
421 (@pxref{Utilities}), as well as Scheme programming interfaces
422 (@pxref{Programming Interface}).
424 Its @dfn{build daemon} is responsible for building packages on behalf of
425 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
426 binaries from authorized sources (@pxref{Substitutes}).
428 @cindex extensibility of the distribution
429 @cindex customization, of packages
430 Guix includes package definitions for many GNU and non-GNU packages, all
431 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
432 user's computing freedom}. It is @emph{extensible}: users can write
433 their own package definitions (@pxref{Defining Packages}) and make them
434 available as independent package modules (@pxref{Package Modules}). It
435 is also @emph{customizable}: users can @emph{derive} specialized package
436 definitions from existing ones, including from the command line
437 (@pxref{Package Transformation Options}).
439 @cindex functional package management
441 Under the hood, Guix implements the @dfn{functional package management}
442 discipline pioneered by Nix (@pxref{Acknowledgments}).
443 In Guix, the package build and installation process is seen
444 as a @emph{function}, in the mathematical sense. That function takes inputs,
445 such as build scripts, a compiler, and libraries, and
446 returns an installed package. As a pure function, its result depends
447 solely on its inputs---for instance, it cannot refer to software or
448 scripts that were not explicitly passed as inputs. A build function
449 always produces the same result when passed a given set of inputs. It
450 cannot alter the environment of the running system in
451 any way; for instance, it cannot create, modify, or delete files outside
452 of its build and installation directories. This is achieved by running
453 build processes in isolated environments (or @dfn{containers}), where only their
454 explicit inputs are visible.
457 The result of package build functions is @dfn{cached} in the file
458 system, in a special directory called @dfn{the store} (@pxref{The
459 Store}). Each package is installed in a directory of its own in the
460 store---by default under @file{/gnu/store}. The directory name contains
461 a hash of all the inputs used to build that package; thus, changing an
462 input yields a different directory name.
464 This approach is the foundation for the salient features of Guix: support
465 for transactional package upgrade and rollback, per-user installation, and
466 garbage collection of packages (@pxref{Features}).
469 @node GNU Distribution
470 @section GNU Distribution
473 Guix comes with a distribution of the GNU system consisting entirely of
474 free software@footnote{The term ``free'' here refers to the
475 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
476 users of that software}.}. The
477 distribution can be installed on its own (@pxref{System Installation}),
478 but it is also possible to install Guix as a package manager on top of
479 an installed GNU/Linux system (@pxref{Installation}). When we need to
480 distinguish between the two, we refer to the standalone distribution as
483 The distribution provides core GNU packages such as GNU libc, GCC, and
484 Binutils, as well as many GNU and non-GNU applications. The complete
485 list of available packages can be browsed
486 @url{https://www.gnu.org/software/guix/packages,on-line} or by
487 running @command{guix package} (@pxref{Invoking guix package}):
490 guix package --list-available
493 Our goal is to provide a practical 100% free software distribution of
494 Linux-based and other variants of GNU, with a focus on the promotion and
495 tight integration of GNU components, and an emphasis on programs and
496 tools that help users exert that freedom.
498 Packages are currently available on the following platforms:
503 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
506 Intel 32-bit architecture (IA32), Linux-Libre kernel.
509 ARMv7-A architecture with hard float, Thumb-2 and NEON,
510 using the EABI hard-float application binary interface (ABI),
511 and Linux-Libre kernel.
514 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
517 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
520 This configuration is experimental and under development. The easiest
521 way for you to give it a try is by setting up an instance of
522 @code{hurd-vm-service-type} on your GNU/Linux machine
523 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
524 @xref{Contributing}, on how to help!
526 @item mips64el-linux (deprecated)
527 little-endian 64-bit MIPS processors, specifically the Loongson series,
528 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
529 supported; in particular, there is no ongoing work to ensure that this
530 architecture still works. Should someone decide they wish to revive this
531 architecture then the code is still available.
533 @item powerpc64le-linux
534 little-endian 64-bit Power ISA processors, Linux-Libre kernel. This
535 includes POWER9 systems such as the
536 @uref{https://www.fsf.org/news/talos-ii-mainboard-and-talos-ii-lite-mainboard-now-fsf-certified-to-respect-your-freedom,
537 RYF Talos II mainboard}. This platform is available as a "technology
538 preview": although it is supported, substitutes are not yet available
539 from the build farm (@pxref{Substitutes}), and some packages may fail to
540 build (@pxref{Tracking Bugs and Patches}). That said, the Guix
541 community is actively working on improving this support, and now is a
542 great time to try it and get involved!
546 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
547 configuration and Guix takes care of instantiating the configuration in a
548 transactional, reproducible, and stateless fashion (@pxref{System
549 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
550 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
551 Manual}), the well-known GNU utilities and tool chain, as well as the
552 graphical environment or system services of your choice.
554 Guix System is available on all the above platforms except
555 @code{mips64el-linux} and @code{powerpc64le-linux}.
558 For information on porting to other architectures or kernels,
561 Building this distribution is a cooperative effort, and you are invited
562 to join! @xref{Contributing}, for information about how you can help.
565 @c *********************************************************************
567 @chapter Installation
569 @cindex installing Guix
572 We recommend the use of this
573 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
574 shell installer script} to install Guix on top of a running GNU/Linux system,
575 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
576 with the installation of the package manager, which can be done on top of a
577 running GNU/Linux system. If, instead, you want to install the complete GNU
578 operating system, @pxref{System Installation}.} The script automates the
579 download, installation, and initial configuration of Guix. It should be run
583 @cindex foreign distro
584 @cindex directories related to foreign distro
585 When installed on a foreign distro, GNU@tie{}Guix complements the available
586 tools without interference. Its data lives exclusively in two directories,
587 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
588 such as @file{/etc}, are left untouched.
590 Once installed, Guix can be updated by running @command{guix pull}
591 (@pxref{Invoking guix pull}).
593 If you prefer to perform the installation steps manually or want to tweak
594 them, you may find the following subsections useful. They describe the
595 software requirements of Guix, as well as how to install it manually and get
599 * Binary Installation:: Getting Guix running in no time!
600 * Requirements:: Software needed to build and run Guix.
601 * Running the Test Suite:: Testing Guix.
602 * Setting Up the Daemon:: Preparing the build daemon's environment.
603 * Invoking guix-daemon:: Running the build daemon.
604 * Application Setup:: Application-specific setup.
605 * Upgrading Guix:: Upgrading Guix and its build daemon.
608 @node Binary Installation
609 @section Binary Installation
611 @cindex installing Guix from binaries
612 @cindex installer script
613 This section describes how to install Guix on an arbitrary system from a
614 self-contained tarball providing binaries for Guix and for all its
615 dependencies. This is often quicker than installing from source, which
616 is described in the next sections. The only requirement is to have
619 @c Note duplicated from the ``Installation'' node.
621 We recommend the use of this
622 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
623 shell installer script}. The script automates the download, installation, and
624 initial configuration steps described below. It should be run as the root
625 user. As root, you can thus run this:
629 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
630 chmod +x guix-install.sh
634 When you're done, @pxref{Application Setup} for extra configuration you
635 might need, and @ref{Getting Started} for your first steps!
638 Installing goes along these lines:
642 @cindex downloading Guix binary
643 Download the binary tarball from
644 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
645 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
646 @code{i686} (32-bits) machine already running the kernel Linux, and so on
647 (@pxref{GNU Distribution}).
649 @c The following is somewhat duplicated in ``System Installation''.
650 Make sure to download the associated @file{.sig} file and to verify the
651 authenticity of the tarball against it, along these lines:
654 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
655 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
658 If that command fails because you do not have the required public key,
659 then run this command to import it:
662 $ wget '@value{OPENPGP-SIGNING-KEY-URL}' \
663 -qO - | gpg --import -
667 and rerun the @code{gpg --verify} command.
669 Take note that a warning like ``This key is not certified with a trusted
670 signature!'' is normal.
672 @c end authentication part
675 Now, you need to become the @code{root} user. Depending on your distribution,
676 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
680 # tar --warning=no-timestamp -xf \
681 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
682 # mv var/guix /var/ && mv gnu /
685 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
686 The latter contains a ready-to-use profile for @code{root} (see next
689 Do @emph{not} unpack the tarball on a working Guix system since that
690 would overwrite its own essential files.
692 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
693 not emit warnings about ``implausibly old time stamps'' (such
694 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
696 They stem from the fact that all the
697 files in the archive have their modification time set to 1 (which
698 means January 1st, 1970). This is done on purpose to make sure the
699 archive content is independent of its creation time, thus making it
703 Make the profile available under @file{~root/.config/guix/current}, which is
704 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
707 # mkdir -p ~root/.config/guix
708 # ln -sf /var/guix/profiles/per-user/root/current-guix \
709 ~root/.config/guix/current
712 Source @file{etc/profile} to augment @env{PATH} and other relevant
713 environment variables:
716 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
717 source $GUIX_PROFILE/etc/profile
721 Create the group and user accounts for build users as explained below
722 (@pxref{Build Environment Setup}).
725 Run the daemon, and set it to automatically start on boot.
727 If your host distro uses the systemd init system, this can be achieved
730 @c Versions of systemd that supported symlinked service files are not
731 @c yet widely deployed, so we should suggest that users copy the service
734 @c See this thread for more information:
735 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
738 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
739 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
741 # systemctl enable --now gnu-store.mount guix-daemon
744 If your host distro uses the Upstart init system:
747 # initctl reload-configuration
748 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
753 Otherwise, you can still start the daemon manually with:
756 # ~root/.config/guix/current/bin/guix-daemon \
757 --build-users-group=guixbuild
761 Make the @command{guix} command available to other users on the machine,
765 # mkdir -p /usr/local/bin
767 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
770 It is also a good idea to make the Info version of this manual available
774 # mkdir -p /usr/local/share/info
775 # cd /usr/local/share/info
776 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
780 That way, assuming @file{/usr/local/share/info} is in the search path,
781 running @command{info guix} will open this manual (@pxref{Other Info
782 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
786 @cindex substitutes, authorization thereof
787 To use substitutes from @code{@value{SUBSTITUTE-SERVER-1}},
788 @code{@value{SUBSTITUTE-SERVER-2}} or a mirror (@pxref{Substitutes}),
792 # guix archive --authorize < \
793 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER-1}.pub
794 # guix archive --authorize < \
795 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER-2}.pub
799 If you do not enable substitutes, Guix will end up building
800 @emph{everything} from source on your machine, making each installation
801 and upgrade very expensive. @xref{On Trusting Binaries}, for a
802 discussion of reasons why one might want do disable substitutes.
806 Each user may need to perform a few additional steps to make their Guix
807 environment ready for use, @pxref{Application Setup}.
810 Voilà, the installation is complete!
812 You can confirm that Guix is working by installing a sample package into
819 The binary installation tarball can be (re)produced and verified simply
820 by running the following command in the Guix source tree:
823 make guix-binary.@var{system}.tar.xz
827 ...@: which, in turn, runs:
830 guix pack -s @var{system} --localstatedir \
831 --profile-name=current-guix guix
834 @xref{Invoking guix pack}, for more info on this handy tool.
837 @section Requirements
839 This section lists requirements when building Guix from source. The
840 build procedure for Guix is the same as for other GNU software, and is
841 not covered here. Please see the files @file{README} and @file{INSTALL}
842 in the Guix source tree for additional details.
844 @cindex official website
845 GNU Guix is available for download from its website at
846 @url{https://www.gnu.org/software/guix/}.
848 GNU Guix depends on the following packages:
851 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x;
852 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
855 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
856 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
857 Guile,, gnutls-guile, GnuTLS-Guile});
859 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
861 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib},
862 version 0.1.0 or later;
863 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
864 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
866 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.5.0
868 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
870 @item @url{https://www.gnu.org/software/make/, GNU Make}.
873 The following dependencies are optional:
877 @c Note: We need at least 0.13.0 for #:nodelay.
878 Support for build offloading (@pxref{Daemon Offload Setup}) and
879 @command{guix copy} (@pxref{Invoking guix copy}) depends on
880 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
881 version 0.13.0 or later.
884 @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
885 compression and decompression in @command{guix publish} and for
886 substitutes (@pxref{Invoking guix publish}).
889 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
890 the @code{crate} importer (@pxref{Invoking guix import}).
893 @uref{https://www.nongnu.org/guile-lib/doc/ref/htmlprag/, Guile-Lib} for
894 the @code{go} importer (@pxref{Invoking guix import}) and for some of
895 the ``updaters'' (@pxref{Invoking guix refresh}).
898 When @url{http://www.bzip.org, libbz2} is available,
899 @command{guix-daemon} can use it to compress build logs.
902 Unless @option{--disable-daemon} was passed to @command{configure}, the
903 following packages are also needed:
906 @item @url{https://gnupg.org/, GNU libgcrypt};
907 @item @url{https://sqlite.org, SQLite 3};
908 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
912 @cindex state directory
913 When configuring Guix on a system that already has a Guix installation,
914 be sure to specify the same state directory as the existing installation
915 using the @option{--localstatedir} option of the @command{configure}
916 script (@pxref{Directory Variables, @code{localstatedir},, standards,
917 GNU Coding Standards}). Usually, this @var{localstatedir} option is
918 set to the value @file{/var}. The @command{configure} script protects
919 against unintended misconfiguration of @var{localstatedir} so you do not
920 inadvertently corrupt your store (@pxref{The Store}).
922 @node Running the Test Suite
923 @section Running the Test Suite
926 After a successful @command{configure} and @code{make} run, it is a good
927 idea to run the test suite. It can help catch issues with the setup or
928 environment, or bugs in Guix itself---and really, reporting test
929 failures is a good way to help improve the software. To run the test
936 Test cases can run in parallel: you can use the @code{-j} option of
937 GNU@tie{}make to speed things up. The first run may take a few minutes
938 on a recent machine; subsequent runs will be faster because the store
939 that is created for test purposes will already have various things in
942 It is also possible to run a subset of the tests by defining the
943 @code{TESTS} makefile variable as in this example:
946 make check TESTS="tests/store.scm tests/cpio.scm"
949 By default, tests results are displayed at a file level. In order to
950 see the details of every individual test cases, it is possible to define
951 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
954 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
957 The underlying SRFI 64 custom Automake test driver used for the 'check'
958 test suite (located at @file{build-aux/test-driver.scm}) also allows
959 selecting which test cases to run at a finer level, via its
960 @option{--select} and @option{--exclude} options. Here's an example, to
961 run all the test cases from the @file{tests/packages.scm} test file
962 whose names start with ``transaction-upgrade-entry'':
965 export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
966 make check TESTS="tests/packages.scm"
969 Those wishing to inspect the results of failed tests directly from the
970 command line can add the @option{--errors-only=yes} option to the
971 @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
972 Automake makefile variable, as in:
975 make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
978 The @option{--show-duration=yes} option can be used to print the
979 duration of the individual test cases, when used in combination with
983 make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
986 @xref{Parallel Test Harness,,,automake,GNU Automake} for more
987 information about the Automake Parallel Test Harness.
989 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
990 @file{test-suite.log} file. Please specify the Guix version being used
991 as well as version numbers of the dependencies (@pxref{Requirements}) in
994 Guix also comes with a whole-system test suite that tests complete
995 Guix System instances. It can only run on systems where
996 Guix is already installed, using:
1003 or, again, by defining @code{TESTS} to select a subset of tests to run:
1006 make check-system TESTS="basic mcron"
1009 These system tests are defined in the @code{(gnu tests @dots{})}
1010 modules. They work by running the operating systems under test with
1011 lightweight instrumentation in a virtual machine (VM). They can be
1012 computationally intensive or rather cheap, depending on whether
1013 substitutes are available for their dependencies (@pxref{Substitutes}).
1014 Some of them require a lot of storage space to hold VM images.
1016 Again in case of test failures, please send @email{bug-guix@@gnu.org}
1019 @node Setting Up the Daemon
1020 @section Setting Up the Daemon
1023 Operations such as building a package or running the garbage collector
1024 are all performed by a specialized process, the @dfn{build daemon}, on
1025 behalf of clients. Only the daemon may access the store and its
1026 associated database. Thus, any operation that manipulates the store
1027 goes through the daemon. For instance, command-line tools such as
1028 @command{guix package} and @command{guix build} communicate with the
1029 daemon (@i{via} remote procedure calls) to instruct it what to do.
1031 The following sections explain how to prepare the build daemon's
1032 environment. See also @ref{Substitutes}, for information on how to allow
1033 the daemon to download pre-built binaries.
1036 * Build Environment Setup:: Preparing the isolated build environment.
1037 * Daemon Offload Setup:: Offloading builds to remote machines.
1038 * SELinux Support:: Using an SELinux policy for the daemon.
1041 @node Build Environment Setup
1042 @subsection Build Environment Setup
1044 @cindex build environment
1045 In a standard multi-user setup, Guix and its daemon---the
1046 @command{guix-daemon} program---are installed by the system
1047 administrator; @file{/gnu/store} is owned by @code{root} and
1048 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
1049 Guix tools to build packages or otherwise access the store, and the
1050 daemon will do it on their behalf, ensuring that the store is kept in a
1051 consistent state, and allowing built packages to be shared among users.
1054 When @command{guix-daemon} runs as @code{root}, you may not want package
1055 build processes themselves to run as @code{root} too, for obvious
1056 security reasons. To avoid that, a special pool of @dfn{build users}
1057 should be created for use by build processes started by the daemon.
1058 These build users need not have a shell and a home directory: they will
1059 just be used when the daemon drops @code{root} privileges in build
1060 processes. Having several such users allows the daemon to launch
1061 distinct build processes under separate UIDs, which guarantees that they
1062 do not interfere with each other---an essential feature since builds are
1063 regarded as pure functions (@pxref{Introduction}).
1065 On a GNU/Linux system, a build user pool may be created like this (using
1066 Bash syntax and the @code{shadow} commands):
1068 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
1069 @c for why `-G' is needed.
1071 # groupadd --system guixbuild
1072 # for i in $(seq -w 1 10);
1074 useradd -g guixbuild -G guixbuild \
1075 -d /var/empty -s $(which nologin) \
1076 -c "Guix build user $i" --system \
1082 The number of build users determines how many build jobs may run in
1083 parallel, as specified by the @option{--max-jobs} option
1084 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1085 @command{guix system vm} and related commands, you may need to add the
1086 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1087 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1088 (@pxref{Invoking guix system}).
1090 The @code{guix-daemon} program may then be run as @code{root} with the
1091 following command@footnote{If your machine uses the systemd init system,
1092 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1093 file in @file{/etc/systemd/system} will ensure that
1094 @command{guix-daemon} is automatically started. Similarly, if your
1095 machine uses the Upstart init system, drop the
1096 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1097 file in @file{/etc/init}.}:
1100 # guix-daemon --build-users-group=guixbuild
1105 This way, the daemon starts build processes in a chroot, under one of
1106 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1107 environment contains nothing but:
1109 @c Keep this list in sync with libstore/build.cc! -----------------------
1112 a minimal @code{/dev} directory, created mostly independently from the
1113 host @code{/dev}@footnote{``Mostly'', because while the set of files
1114 that appear in the chroot's @code{/dev} is fixed, most of these files
1115 can only be created if the host has them.};
1118 the @code{/proc} directory; it only shows the processes of the container
1119 since a separate PID name space is used;
1122 @file{/etc/passwd} with an entry for the current user and an entry for
1126 @file{/etc/group} with an entry for the user's group;
1129 @file{/etc/hosts} with an entry that maps @code{localhost} to
1133 a writable @file{/tmp} directory.
1136 You can influence the directory where the daemon stores build trees
1137 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1138 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1139 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1140 This way, the value of @env{TMPDIR} does not leak inside build
1141 environments, which avoids discrepancies in cases where build processes
1142 capture the name of their build tree.
1146 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1147 environment variables for HTTP and HTTPS downloads it performs, be it
1148 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1149 (@pxref{Substitutes}).
1151 If you are installing Guix as an unprivileged user, it is still possible
1152 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1153 However, build processes will not be isolated from one another, and not
1154 from the rest of the system. Thus, build processes may interfere with
1155 each other, and may access programs, libraries, and other files
1156 available on the system---making it much harder to view them as
1157 @emph{pure} functions.
1160 @node Daemon Offload Setup
1161 @subsection Using the Offload Facility
1165 When desired, the build daemon can @dfn{offload} derivation builds to
1166 other machines running Guix, using the @code{offload} @dfn{build
1167 hook}@footnote{This feature is available only when
1168 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1169 present.}. When that feature is enabled, a list of user-specified build
1170 machines is read from @file{/etc/guix/machines.scm}; every time a build
1171 is requested, for instance via @code{guix build}, the daemon attempts to
1172 offload it to one of the machines that satisfy the constraints of the
1173 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1174 A single machine can have multiple system types, either because its
1175 architecture natively supports it, via emulation
1176 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1177 or both. Missing prerequisites for the build are
1178 copied over SSH to the target machine, which then proceeds with the
1179 build; upon success the output(s) of the build are copied back to the
1180 initial machine. The offload facility comes with a basic scheduler that
1181 attempts to select the best machine. The best machine is chosen among
1182 the available machines based on criteria such as:
1186 The availability of a build slot. A build machine can have as many
1187 build slots (connections) as the value of the @code{parallel-builds}
1188 field of its @code{build-machine} object.
1191 Its relative speed, as defined via the @code{speed} field of its
1192 @code{build-machine} object.
1195 Its load. The normalized machine load must be lower than a threshold
1196 value, configurable via the @code{overload-threshold} field of its
1197 @code{build-machine} object.
1200 Disk space availability. More than a 100 MiB must be available.
1203 The @file{/etc/guix/machines.scm} file typically looks like this:
1206 (list (build-machine
1207 (name "eightysix.example.org")
1208 (systems (list "x86_64-linux" "i686-linux"))
1209 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1211 (speed 2.)) ;incredibly fast!
1214 (name "armeight.example.org")
1215 (systems (list "aarch64-linux"))
1216 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1219 (string-append (getenv "HOME")
1220 "/.ssh/identity-for-guix"))))
1224 In the example above we specify a list of two build machines, one for
1225 the @code{x86_64} and @code{i686} architectures and one for the
1226 @code{aarch64} architecture.
1228 In fact, this file is---not surprisingly!---a Scheme file that is
1229 evaluated when the @code{offload} hook is started. Its return value
1230 must be a list of @code{build-machine} objects. While this example
1231 shows a fixed list of build machines, one could imagine, say, using
1232 DNS-SD to return a list of potential build machines discovered in the
1233 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1234 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1237 @deftp {Data Type} build-machine
1238 This data type represents build machines to which the daemon may offload
1239 builds. The important fields are:
1244 The host name of the remote machine.
1247 The system types the remote machine supports---e.g., @code{(list
1248 "x86_64-linux" "i686-linux")}.
1251 The user account to use when connecting to the remote machine over SSH.
1252 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1253 allow non-interactive logins.
1256 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1257 This is used to authenticate the machine when we connect to it. It is a
1258 long string that looks like this:
1261 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1264 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1265 key can be found in a file such as
1266 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1268 If the machine is running the SSH daemon of GNU@tie{}lsh,
1269 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1270 similar file. It can be converted to the OpenSSH format using
1271 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1274 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1275 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1280 A number of optional fields may be specified:
1284 @item @code{port} (default: @code{22})
1285 Port number of SSH server on the machine.
1287 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1288 The SSH private key file to use when connecting to the machine, in
1289 OpenSSH format. This key must not be protected with a passphrase.
1291 Note that the default value is the private key @emph{of the root
1292 account}. Make sure it exists if you use the default.
1294 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1295 @itemx @code{compression-level} (default: @code{3})
1296 The SSH-level compression methods and compression level requested.
1298 Note that offloading relies on SSH compression to reduce bandwidth usage
1299 when transferring files to and from build machines.
1301 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1302 File name of the Unix-domain socket @command{guix-daemon} is listening
1305 @item @code{overload-threshold} (default: @code{0.6})
1306 The load threshold above which a potential offload machine is
1307 disregarded by the offload scheduler. The value roughly translates to
1308 the total processor usage of the build machine, ranging from 0.0 (0%) to
1309 1.0 (100%). It can also be disabled by setting
1310 @code{overload-threshold} to @code{#f}.
1312 @item @code{parallel-builds} (default: @code{1})
1313 The number of builds that may run in parallel on the machine.
1315 @item @code{speed} (default: @code{1.0})
1316 A ``relative speed factor''. The offload scheduler will tend to prefer
1317 machines with a higher speed factor.
1319 @item @code{features} (default: @code{'()})
1320 A list of strings denoting specific features supported by the machine.
1321 An example is @code{"kvm"} for machines that have the KVM Linux modules
1322 and corresponding hardware support. Derivations can request features by
1323 name, and they will be scheduled on matching build machines.
1328 The @command{guix} command must be in the search path on the build
1329 machines. You can check whether this is the case by running:
1332 ssh build-machine guix repl --version
1335 There is one last thing to do once @file{machines.scm} is in place. As
1336 explained above, when offloading, files are transferred back and forth
1337 between the machine stores. For this to work, you first need to
1338 generate a key pair on each machine to allow the daemon to export signed
1339 archives of files from the store (@pxref{Invoking guix archive}):
1342 # guix archive --generate-key
1346 Each build machine must authorize the key of the master machine so that
1347 it accepts store items it receives from the master:
1350 # guix archive --authorize < master-public-key.txt
1354 Likewise, the master machine must authorize the key of each build machine.
1356 All the fuss with keys is here to express pairwise mutual trust
1357 relations between the master and the build machines. Concretely, when
1358 the master receives files from a build machine (and @i{vice versa}), its
1359 build daemon can make sure they are genuine, have not been tampered
1360 with, and that they are signed by an authorized key.
1362 @cindex offload test
1363 To test whether your setup is operational, run this command on the
1370 This will attempt to connect to each of the build machines specified in
1371 @file{/etc/guix/machines.scm}, make sure Guix is
1372 available on each machine, attempt to export to the machine and import
1373 from it, and report any error in the process.
1375 If you want to test a different machine file, just specify it on the
1379 # guix offload test machines-qualif.scm
1382 Last, you can test the subset of the machines whose name matches a
1383 regular expression like this:
1386 # guix offload test machines.scm '\.gnu\.org$'
1389 @cindex offload status
1390 To display the current load of all build hosts, run this command on the
1394 # guix offload status
1398 @node SELinux Support
1399 @subsection SELinux Support
1401 @cindex SELinux, daemon policy
1402 @cindex mandatory access control, SELinux
1403 @cindex security, guix-daemon
1404 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1405 can be installed on a system where SELinux is enabled, in order to label
1406 Guix files and to specify the expected behavior of the daemon. Since
1407 Guix System does not provide an SELinux base policy, the daemon policy cannot
1408 be used on Guix System.
1410 @subsubsection Installing the SELinux policy
1411 @cindex SELinux, policy installation
1412 To install the policy run this command as root:
1415 semodule -i etc/guix-daemon.cil
1418 Then relabel the file system with @code{restorecon} or by a different
1419 mechanism provided by your system.
1421 Once the policy is installed, the file system has been relabeled, and
1422 the daemon has been restarted, it should be running in the
1423 @code{guix_daemon_t} context. You can confirm this with the following
1427 ps -Zax | grep guix-daemon
1430 Monitor the SELinux log files as you run a command like @code{guix build
1431 hello} to convince yourself that SELinux permits all necessary
1434 @subsubsection Limitations
1435 @cindex SELinux, limitations
1437 This policy is not perfect. Here is a list of limitations or quirks
1438 that should be considered when deploying the provided SELinux policy for
1443 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1444 operations involve contexts that have anything to do with
1445 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1446 but it would be preferable to define socket rules for only this label.
1449 @code{guix gc} cannot access arbitrary links to profiles. By design,
1450 the file label of the destination of a symlink is independent of the
1451 file label of the link itself. Although all profiles under
1452 $localstatedir are labelled, the links to these profiles inherit the
1453 label of the directory they are in. For links in the user’s home
1454 directory this will be @code{user_home_t}. But for links from the root
1455 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1456 directory, etc, this won’t work. @code{guix gc} would be prevented from
1457 reading and following these links.
1460 The daemon’s feature to listen for TCP connections might no longer work.
1461 This might require extra rules, because SELinux treats network sockets
1462 differently from files.
1465 Currently all files with a name matching the regular expression
1466 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1467 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1468 that name in any profile would be permitted to run in the
1469 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1470 build a package that provides this executable and convince a user to
1471 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1472 At that point SELinux could not prevent it from accessing files that are
1473 allowed for processes in that domain.
1475 You will need to relabel the store directory after all upgrades to
1476 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1477 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1478 or by other means provided by your operating system.
1480 We could generate a much more restrictive policy at installation time,
1481 so that only the @emph{exact} file name of the currently installed
1482 @code{guix-daemon} executable would be labelled with
1483 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1484 The downside is that root would have to install or upgrade the policy at
1485 installation time whenever the Guix package that provides the
1486 effectively running @code{guix-daemon} executable is upgraded.
1489 @node Invoking guix-daemon
1490 @section Invoking @command{guix-daemon}
1492 The @command{guix-daemon} program implements all the functionality to
1493 access the store. This includes launching build processes, running the
1494 garbage collector, querying the availability of a build result, etc. It
1495 is normally run as @code{root} like this:
1498 # guix-daemon --build-users-group=guixbuild
1502 For details on how to set it up, @pxref{Setting Up the Daemon}.
1505 @cindex container, build environment
1506 @cindex build environment
1507 @cindex reproducible builds
1508 By default, @command{guix-daemon} launches build processes under
1509 different UIDs, taken from the build group specified with
1510 @option{--build-users-group}. In addition, each build process is run in a
1511 chroot environment that only contains the subset of the store that the
1512 build process depends on, as specified by its derivation
1513 (@pxref{Programming Interface, derivation}), plus a set of specific
1514 system directories. By default, the latter contains @file{/dev} and
1515 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1516 @dfn{container}: in addition to having its own file system tree, it has
1517 a separate mount name space, its own PID name space, network name space,
1518 etc. This helps achieve reproducible builds (@pxref{Features}).
1520 When the daemon performs a build on behalf of the user, it creates a
1521 build directory under @file{/tmp} or under the directory specified by
1522 its @env{TMPDIR} environment variable. This directory is shared with
1523 the container for the duration of the build, though within the container,
1524 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1526 The build directory is automatically deleted upon completion, unless the
1527 build failed and the client specified @option{--keep-failed}
1528 (@pxref{Common Build Options, @option{--keep-failed}}).
1530 The daemon listens for connections and spawns one sub-process for each session
1531 started by a client (one of the @command{guix} sub-commands). The
1532 @command{guix processes} command allows you to get an overview of the activity
1533 on your system by viewing each of the active sessions and clients.
1534 @xref{Invoking guix processes}, for more information.
1536 The following command-line options are supported:
1539 @item --build-users-group=@var{group}
1540 Take users from @var{group} to run build processes (@pxref{Setting Up
1541 the Daemon, build users}).
1543 @item --no-substitutes
1545 Do not use substitutes for build products. That is, always build things
1546 locally instead of allowing downloads of pre-built binaries
1547 (@pxref{Substitutes}).
1549 When the daemon runs with @option{--no-substitutes}, clients can still
1550 explicitly enable substitution @i{via} the @code{set-build-options}
1551 remote procedure call (@pxref{The Store}).
1553 @anchor{daemon-substitute-urls}
1554 @item --substitute-urls=@var{urls}
1555 Consider @var{urls} the default whitespace-separated list of substitute
1556 source URLs. When this option is omitted,
1557 @indicateurl{@value{SUBSTITUTE-URLS}} is used.
1559 This means that substitutes may be downloaded from @var{urls}, as long
1560 as they are signed by a trusted signature (@pxref{Substitutes}).
1562 @xref{Getting Substitutes from Other Servers}, for more information on
1563 how to configure the daemon to get substitutes from other servers.
1567 Do not use offload builds to other machines (@pxref{Daemon Offload
1568 Setup}). That is, always build things locally instead of offloading
1569 builds to remote machines.
1571 @item --cache-failures
1572 Cache build failures. By default, only successful builds are cached.
1574 When this option is used, @command{guix gc --list-failures} can be used
1575 to query the set of store items marked as failed; @command{guix gc
1576 --clear-failures} removes store items from the set of cached failures.
1577 @xref{Invoking guix gc}.
1579 @item --cores=@var{n}
1581 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1584 The default value is @code{0}, but it may be overridden by clients, such
1585 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1588 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1589 in the build process, which can then use it to exploit internal
1590 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1592 @item --max-jobs=@var{n}
1594 Allow at most @var{n} build jobs in parallel. The default value is
1595 @code{1}. Setting it to @code{0} means that no builds will be performed
1596 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1597 Setup}), or simply fail.
1599 @item --max-silent-time=@var{seconds}
1600 When the build or substitution process remains silent for more than
1601 @var{seconds}, terminate it and report a build failure.
1603 The default value is @code{0}, which disables the timeout.
1605 The value specified here can be overridden by clients (@pxref{Common
1606 Build Options, @option{--max-silent-time}}).
1608 @item --timeout=@var{seconds}
1609 Likewise, when the build or substitution process lasts for more than
1610 @var{seconds}, terminate it and report a build failure.
1612 The default value is @code{0}, which disables the timeout.
1614 The value specified here can be overridden by clients (@pxref{Common
1615 Build Options, @option{--timeout}}).
1617 @item --rounds=@var{N}
1618 Build each derivation @var{n} times in a row, and raise an error if
1619 consecutive build results are not bit-for-bit identical. Note that this
1620 setting can be overridden by clients such as @command{guix build}
1621 (@pxref{Invoking guix build}).
1623 When used in conjunction with @option{--keep-failed}, the differing
1624 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1625 This makes it easy to look for differences between the two results.
1628 Produce debugging output.
1630 This is useful to debug daemon start-up issues, but then it may be
1631 overridden by clients, for example the @option{--verbosity} option of
1632 @command{guix build} (@pxref{Invoking guix build}).
1634 @item --chroot-directory=@var{dir}
1635 Add @var{dir} to the build chroot.
1637 Doing this may change the result of build processes---for instance if
1638 they use optional dependencies found in @var{dir} when it is available,
1639 and not otherwise. For that reason, it is not recommended to do so.
1640 Instead, make sure that each derivation declares all the inputs that it
1643 @item --disable-chroot
1644 Disable chroot builds.
1646 Using this option is not recommended since, again, it would allow build
1647 processes to gain access to undeclared dependencies. It is necessary,
1648 though, when @command{guix-daemon} is running under an unprivileged user
1651 @item --log-compression=@var{type}
1652 Compress build logs according to @var{type}, one of @code{gzip},
1653 @code{bzip2}, or @code{none}.
1655 Unless @option{--lose-logs} is used, all the build logs are kept in the
1656 @var{localstatedir}. To save space, the daemon automatically compresses
1657 them with Bzip2 by default.
1659 @item --discover[=yes|no]
1660 Whether to discover substitute servers on the local network using mDNS
1663 This feature is still experimental. However, here are a few
1668 It might be faster/less expensive than fetching from remote servers;
1670 There are no security risks, only genuine substitutes will be used
1671 (@pxref{Substitute Authentication});
1673 An attacker advertising @command{guix publish} on your LAN cannot serve
1674 you malicious binaries, but they can learn what software you’re
1677 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1678 LAN can see what software you’re installing.
1681 It is also possible to enable or disable substitute server discovery at
1682 run-time by running:
1685 herd discover guix-daemon on
1686 herd discover guix-daemon off
1689 @item --disable-deduplication
1690 @cindex deduplication
1691 Disable automatic file ``deduplication'' in the store.
1693 By default, files added to the store are automatically ``deduplicated'':
1694 if a newly added file is identical to another one found in the store,
1695 the daemon makes the new file a hard link to the other file. This can
1696 noticeably reduce disk usage, at the expense of slightly increased
1697 input/output load at the end of a build process. This option disables
1700 @item --gc-keep-outputs[=yes|no]
1701 Tell whether the garbage collector (GC) must keep outputs of live
1705 @cindex garbage collector roots
1706 When set to @code{yes}, the GC will keep the outputs of any live
1707 derivation available in the store---the @file{.drv} files. The default
1708 is @code{no}, meaning that derivation outputs are kept only if they are
1709 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1712 @item --gc-keep-derivations[=yes|no]
1713 Tell whether the garbage collector (GC) must keep derivations
1714 corresponding to live outputs.
1716 When set to @code{yes}, as is the case by default, the GC keeps
1717 derivations---i.e., @file{.drv} files---as long as at least one of their
1718 outputs is live. This allows users to keep track of the origins of
1719 items in their store. Setting it to @code{no} saves a bit of disk
1722 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1723 liveness to flow from outputs to derivations, and setting
1724 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1725 derivations to outputs. When both are set to @code{yes}, the effect is
1726 to keep all the build prerequisites (the sources, compiler, libraries,
1727 and other build-time tools) of live objects in the store, regardless of
1728 whether these prerequisites are reachable from a GC root. This is
1729 convenient for developers since it saves rebuilds or downloads.
1731 @item --impersonate-linux-2.6
1732 On Linux-based systems, impersonate Linux 2.6. This means that the
1733 kernel's @command{uname} system call will report 2.6 as the release number.
1735 This might be helpful to build programs that (usually wrongfully) depend
1736 on the kernel version number.
1739 Do not keep build logs. By default they are kept under
1740 @file{@var{localstatedir}/guix/log}.
1742 @item --system=@var{system}
1743 Assume @var{system} as the current system type. By default it is the
1744 architecture/kernel pair found at configure time, such as
1745 @code{x86_64-linux}.
1747 @item --listen=@var{endpoint}
1748 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1749 as the file name of a Unix-domain socket if it starts with
1750 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1751 host name or host name and port to listen to. Here are a few examples:
1754 @item --listen=/gnu/var/daemon
1755 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1756 creating it if needed.
1758 @item --listen=localhost
1759 @cindex daemon, remote access
1760 @cindex remote access to the daemon
1761 @cindex daemon, cluster setup
1762 @cindex clusters, daemon setup
1763 Listen for TCP connections on the network interface corresponding to
1764 @code{localhost}, on port 44146.
1766 @item --listen=128.0.0.42:1234
1767 Listen for TCP connections on the network interface corresponding to
1768 @code{128.0.0.42}, on port 1234.
1771 This option can be repeated multiple times, in which case
1772 @command{guix-daemon} accepts connections on all the specified
1773 endpoints. Users can tell client commands what endpoint to connect to
1774 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1775 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1778 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1779 @option{--listen=@var{host}} is suitable on local networks, such as
1780 clusters, where only trusted nodes may connect to the build daemon. In
1781 other cases where remote access to the daemon is needed, we recommend
1782 using Unix-domain sockets along with SSH.
1785 When @option{--listen} is omitted, @command{guix-daemon} listens for
1786 connections on the Unix-domain socket located at
1787 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1791 @node Application Setup
1792 @section Application Setup
1794 @cindex foreign distro
1795 When using Guix on top of GNU/Linux distribution other than Guix System---a
1796 so-called @dfn{foreign distro}---a few additional steps are needed to
1797 get everything in place. Here are some of them.
1801 @anchor{locales-and-locpath}
1802 @cindex locales, when not on Guix System
1804 @vindex GUIX_LOCPATH
1805 Packages installed @i{via} Guix will not use the locale data of the
1806 host system. Instead, you must first install one of the locale packages
1807 available with Guix and then define the @env{GUIX_LOCPATH} environment
1811 $ guix install glibc-locales
1812 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1815 Note that the @code{glibc-locales} package contains data for all the
1816 locales supported by the GNU@tie{}libc and weighs in at around
1817 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
1818 limited to a few UTF-8 locales.
1820 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1821 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1822 Manual}). There are two important differences though:
1826 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1827 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1828 to make sure the programs of the foreign distro will not end up loading
1829 incompatible locale data.
1832 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1833 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1834 should your Guix profile contain a mixture of programs linked against
1835 different libc version, each libc version will only try to load locale
1836 data in the right format.
1839 This is important because the locale data format used by different libc
1840 versions may be incompatible.
1842 @subsection Name Service Switch
1844 @cindex name service switch, glibc
1845 @cindex NSS (name service switch), glibc
1846 @cindex nscd (name service caching daemon)
1847 @cindex name service caching daemon (nscd)
1848 When using Guix on a foreign distro, we @emph{strongly recommend} that
1849 the system run the GNU C library's @dfn{name service cache daemon},
1850 @command{nscd}, which should be listening on the
1851 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1852 installed with Guix may fail to look up host names or user accounts, or
1853 may even crash. The next paragraphs explain why.
1855 @cindex @file{nsswitch.conf}
1856 The GNU C library implements a @dfn{name service switch} (NSS), which is
1857 an extensible mechanism for ``name lookups'' in general: host name
1858 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1859 The GNU C Library Reference Manual}).
1861 @cindex Network information service (NIS)
1862 @cindex NIS (Network information service)
1863 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1864 lookup implementations: for example, the @code{nss-mdns} plugin allow
1865 resolution of @code{.local} host names, the @code{nis} plugin allows
1866 user account lookup using the Network information service (NIS), and so
1867 on. These extra ``lookup services'' are configured system-wide in
1868 @file{/etc/nsswitch.conf}, and all the programs running on the system
1869 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1872 When they perform a name lookup---for instance by calling the
1873 @code{getaddrinfo} function in C---applications first try to connect to
1874 the nscd; on success, nscd performs name lookups on their behalf. If
1875 the nscd is not running, then they perform the name lookup by
1876 themselves, by loading the name lookup services into their own address
1877 space and running it. These name lookup services---the
1878 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1879 the host system's C library, rather than from the C library the
1880 application is linked against (the C library coming from Guix).
1882 And this is where the problem is: if your application is linked against
1883 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1884 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1885 likely crash or have its name lookups fail unexpectedly.
1887 Running @command{nscd} on the system, among other advantages, eliminates
1888 this binary incompatibility problem because those @code{libnss_*.so}
1889 files are loaded in the @command{nscd} process, not in applications
1892 @subsection X11 Fonts
1895 The majority of graphical applications use Fontconfig to locate and
1896 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1897 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1898 by default. Thus, to allow graphical applications installed with Guix
1899 to display fonts, you have to install fonts with Guix as well.
1900 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1901 @code{font-gnu-freefont}.
1903 @cindex @code{fc-cache}
1905 Once you have installed or removed fonts, or when you notice an
1906 application that does not find fonts, you may need to install Fontconfig
1907 and to force an update of its font cache by running:
1910 guix install fontconfig
1914 To display text written in Chinese languages, Japanese, or Korean in
1915 graphical applications, consider installing
1916 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1917 has multiple outputs, one per language family (@pxref{Packages with
1918 Multiple Outputs}). For instance, the following command installs fonts
1919 for Chinese languages:
1922 guix install font-adobe-source-han-sans:cn
1925 @cindex @code{xterm}
1926 Older programs such as @command{xterm} do not use Fontconfig and instead
1927 rely on server-side font rendering. Such programs require to specify a
1928 full name of a font using XLFD (X Logical Font Description), like this:
1931 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1934 To be able to use such full names for the TrueType fonts installed in
1935 your Guix profile, you need to extend the font path of the X server:
1937 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1938 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1940 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1943 @cindex @code{xlsfonts}
1944 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1945 to make sure your TrueType fonts are listed there.
1948 @subsection X.509 Certificates
1950 @cindex @code{nss-certs}
1951 The @code{nss-certs} package provides X.509 certificates, which allow
1952 programs to authenticate Web servers accessed over HTTPS.
1954 When using Guix on a foreign distro, you can install this package and
1955 define the relevant environment variables so that packages know where to
1956 look for certificates. @xref{X.509 Certificates}, for detailed
1959 @subsection Emacs Packages
1961 @cindex @code{emacs}
1962 When you install Emacs packages with Guix, the Elisp files are placed
1963 under the @file{share/emacs/site-lisp/} directory of the profile in
1964 which they are installed. The Elisp libraries are made available to
1965 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1966 set when installing Emacs itself.
1968 Additionally, autoload definitions are automatically evaluated at the
1969 initialization of Emacs, by the Guix-specific
1970 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1971 want to avoid auto-loading the Emacs packages installed with Guix, you
1972 can do so by running Emacs with the @option{--no-site-file} option
1973 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1976 @node Upgrading Guix
1977 @section Upgrading Guix
1979 @cindex Upgrading Guix, on a foreign distro
1981 To upgrade Guix, run:
1987 @xref{Invoking guix pull}, for more information.
1989 @cindex upgrading Guix for the root user, on a foreign distro
1990 @cindex upgrading the Guix daemon, on a foreign distro
1991 @cindex @command{guix pull} for the root user, on a foreign distro
1993 On a foreign distro, you can upgrade the build daemon by running:
2000 followed by (assuming your distro uses the systemd service management
2004 systemctl restart guix-daemon.service
2007 On Guix System, upgrading the daemon is achieved by reconfiguring the
2008 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
2012 @c *********************************************************************
2013 @node System Installation
2014 @chapter System Installation
2016 @cindex installing Guix System
2017 @cindex Guix System, installation
2018 This section explains how to install Guix System
2019 on a machine. Guix, as a package manager, can
2020 also be installed on top of a running GNU/Linux system,
2021 @pxref{Installation}.
2025 @c This paragraph is for people reading this from tty2 of the
2026 @c installation image.
2027 You are reading this documentation with an Info reader. For details on
2028 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
2029 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
2030 Info}. Hit @kbd{l} afterwards to come back here.
2032 Alternatively, run @command{info info} in another tty to keep the manual
2038 * Limitations:: What you can expect.
2039 * Hardware Considerations:: Supported hardware.
2040 * USB Stick and DVD Installation:: Preparing the installation medium.
2041 * Preparing for Installation:: Networking, partitioning, etc.
2042 * Guided Graphical Installation:: Easy graphical installation.
2043 * Manual Installation:: Manual installation for wizards.
2044 * After System Installation:: When installation succeeded.
2045 * Installing Guix in a VM:: Guix System playground.
2046 * Building the Installation Image:: How this comes to be.
2050 @section Limitations
2052 We consider Guix System to be ready for a wide range of ``desktop'' and server
2053 use cases. The reliability guarantees it provides---transactional upgrades
2054 and rollbacks, reproducibility---make it a solid foundation.
2056 Nevertheless, before you proceed with the installation, be aware of the
2057 following noteworthy limitations applicable to version @value{VERSION}:
2061 More and more system services are provided (@pxref{Services}), but some
2065 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
2066 as well as a number of X11 window managers. However, KDE is currently
2070 More than a disclaimer, this is an invitation to report issues (and success
2071 stories!), and to join us in improving it. @xref{Contributing}, for more
2075 @node Hardware Considerations
2076 @section Hardware Considerations
2078 @cindex hardware support on Guix System
2079 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2080 builds around the kernel Linux-libre, which means that only hardware for
2081 which free software drivers and firmware exist is supported. Nowadays,
2082 a wide range of off-the-shelf hardware is supported on
2083 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2084 Ethernet controllers. Unfortunately, there are still areas where
2085 hardware vendors deny users control over their own computing, and such
2086 hardware is not supported on Guix System.
2088 @cindex WiFi, hardware support
2089 One of the main areas where free drivers or firmware are lacking is WiFi
2090 devices. WiFi devices known to work include those using Atheros chips
2091 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2092 driver, and those using Broadcom/AirForce chips (BCM43xx with
2093 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2094 Linux-libre driver. Free firmware exists for both and is available
2095 out-of-the-box on Guix System, as part of @code{%base-firmware}
2096 (@pxref{operating-system Reference, @code{firmware}}).
2098 @cindex RYF, Respects Your Freedom
2099 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2100 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2101 certification program for hardware products that respect your freedom
2102 and your privacy and ensure that you have control over your device. We
2103 encourage you to check the list of RYF-certified devices.
2105 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2106 web site. It contains a catalog of hardware devices with information
2107 about their support in GNU/Linux.
2110 @node USB Stick and DVD Installation
2111 @section USB Stick and DVD Installation
2113 An ISO-9660 installation image that can be written to a USB stick or
2114 burnt to a DVD can be downloaded from
2115 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso},
2116 where you can replace @code{x86_64-linux} with one of:
2120 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2123 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2126 @c start duplication of authentication part from ``Binary Installation''
2127 Make sure to download the associated @file{.sig} file and to verify the
2128 authenticity of the image against it, along these lines:
2131 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.sig
2132 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.sig
2135 If that command fails because you do not have the required public key,
2136 then run this command to import it:
2139 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2140 -qO - | gpg --import -
2144 and rerun the @code{gpg --verify} command.
2146 Take note that a warning like ``This key is not certified with a trusted
2147 signature!'' is normal.
2151 This image contains the tools necessary for an installation.
2152 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2154 @unnumberedsubsec Copying to a USB Stick
2156 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2157 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2158 copy the image with:
2161 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2165 Access to @file{/dev/sdX} usually requires root privileges.
2167 @unnumberedsubsec Burning on a DVD
2169 Insert a blank DVD into your machine, and determine
2170 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2171 copy the image with:
2174 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2177 Access to @file{/dev/srX} usually requires root privileges.
2179 @unnumberedsubsec Booting
2181 Once this is done, you should be able to reboot the system and boot from
2182 the USB stick or DVD@. The latter usually requires you to get in the
2183 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2184 In order to boot from Libreboot, switch to the command mode by pressing
2185 the @kbd{c} key and type @command{search_grub usb}.
2187 @xref{Installing Guix in a VM}, if, instead, you would like to install
2188 Guix System in a virtual machine (VM).
2191 @node Preparing for Installation
2192 @section Preparing for Installation
2194 Once you have booted, you can use the guided graphical installer, which makes
2195 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2196 if you are already familiar with GNU/Linux and if you want more control than
2197 what the graphical installer provides, you can choose the ``manual''
2198 installation process (@pxref{Manual Installation}).
2200 The graphical installer is available on TTY1. You can obtain root shells on
2201 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2202 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2203 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2204 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2205 which allows you to select text with the left mouse button and to paste it
2206 with the middle button.
2209 Installation requires access to the Internet so that any missing
2210 dependencies of your system configuration can be downloaded. See the
2211 ``Networking'' section below.
2214 @node Guided Graphical Installation
2215 @section Guided Graphical Installation
2217 The graphical installer is a text-based user interface. It will guide you,
2218 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2220 The first dialog boxes allow you to set up the system as you use it during the
2221 installation: you can choose the language, keyboard layout, and set up
2222 networking, which will be used during the installation. The image below shows
2223 the networking dialog.
2225 @image{images/installer-network,5in,, networking setup with the graphical installer}
2227 Later steps allow you to partition your hard disk, as shown in the image
2228 below, to choose whether or not to use encrypted file systems, to enter the
2229 host name and root password, and to create an additional account, among other
2232 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2234 Note that, at any time, the installer allows you to exit the current
2235 installation step and resume at a previous step, as show in the image below.
2237 @image{images/installer-resume,5in,, resuming the installation process}
2239 Once you're done, the installer produces an operating system configuration and
2240 displays it (@pxref{Using the Configuration System}). At that point you can
2241 hit ``OK'' and installation will proceed. On success, you can reboot into the
2242 new system and enjoy. @xref{After System Installation}, for what's next!
2245 @node Manual Installation
2246 @section Manual Installation
2248 This section describes how you would ``manually'' install GNU@tie{}Guix System
2249 on your machine. This option requires familiarity with GNU/Linux, with the
2250 shell, and with common administration tools. If you think this is not for
2251 you, consider using the guided graphical installer (@pxref{Guided Graphical
2254 The installation system provides root shells on TTYs 3 to 6; press
2255 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2256 many common tools needed to install the system. But it is also a full-blown
2257 Guix System, which means that you can install additional packages, should you
2258 need it, using @command{guix package} (@pxref{Invoking guix package}).
2261 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2262 * Proceeding with the Installation:: Installing.
2265 @node Keyboard Layout and Networking and Partitioning
2266 @subsection Keyboard Layout, Networking, and Partitioning
2268 Before you can install the system, you may want to adjust the keyboard layout,
2269 set up networking, and partition your target hard disk. This section will
2270 guide you through this.
2272 @subsubsection Keyboard Layout
2274 @cindex keyboard layout
2275 The installation image uses the US qwerty keyboard layout. If you want
2276 to change it, you can use the @command{loadkeys} command. For example,
2277 the following command selects the Dvorak keyboard layout:
2283 See the files under @file{/run/current-system/profile/share/keymaps} for
2284 a list of available keyboard layouts. Run @command{man loadkeys} for
2287 @subsubsection Networking
2289 Run the following command to see what your network interfaces are called:
2296 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2302 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2303 Wired interfaces have a name starting with @samp{e}; for example, the
2304 interface corresponding to the first on-board Ethernet controller is
2305 called @samp{eno1}. Wireless interfaces have a name starting with
2306 @samp{w}, like @samp{w1p2s0}.
2309 @item Wired connection
2310 To configure a wired network run the following command, substituting
2311 @var{interface} with the name of the wired interface you want to use.
2314 ifconfig @var{interface} up
2318 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2321 ip link set @var{interface} up
2324 @item Wireless connection
2327 To configure wireless networking, you can create a configuration file
2328 for the @command{wpa_supplicant} configuration tool (its location is not
2329 important) using one of the available text editors such as
2333 nano wpa_supplicant.conf
2336 As an example, the following stanza can go to this file and will work
2337 for many wireless networks, provided you give the actual SSID and
2338 passphrase for the network you are connecting to:
2342 ssid="@var{my-ssid}"
2344 psk="the network's secret passphrase"
2348 Start the wireless service and run it in the background with the
2349 following command (substitute @var{interface} with the name of the
2350 network interface you want to use):
2353 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2356 Run @command{man wpa_supplicant} for more information.
2360 At this point, you need to acquire an IP address. On a network where IP
2361 addresses are automatically assigned @i{via} DHCP, you can run:
2364 dhclient -v @var{interface}
2367 Try to ping a server to see if networking is up and running:
2373 Setting up network access is almost always a requirement because the
2374 image does not contain all the software and tools that may be needed.
2376 @cindex proxy, during system installation
2377 If you need HTTP and HTTPS access to go through a proxy, run the
2381 herd set-http-proxy guix-daemon @var{URL}
2385 where @var{URL} is the proxy URL, for example
2386 @code{http://example.org:8118}.
2388 @cindex installing over SSH
2389 If you want to, you can continue the installation remotely by starting
2393 herd start ssh-daemon
2396 Make sure to either set a password with @command{passwd}, or configure
2397 OpenSSH public key authentication before logging in.
2399 @subsubsection Disk Partitioning
2401 Unless this has already been done, the next step is to partition, and
2402 then format the target partition(s).
2404 The installation image includes several partitioning tools, including
2405 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2406 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2407 the partition layout you want:
2413 If your disk uses the GUID Partition Table (GPT) format and you plan to
2414 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2415 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2418 @cindex EFI, installation
2419 @cindex UEFI, installation
2420 @cindex ESP, EFI system partition
2421 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2422 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2423 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2426 parted /dev/sda set 1 esp on
2430 @vindex grub-bootloader
2431 @vindex grub-efi-bootloader
2432 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2433 @file{/sys/firmware/efi} exists in the installation image, then you should
2434 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2435 Otherwise you should use the BIOS-based GRUB, known as
2436 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2440 Once you are done partitioning the target hard disk drive, you have to
2441 create a file system on the relevant partition(s)@footnote{Currently
2442 Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
2443 particular, code that reads file system UUIDs and labels only works for these
2444 file system types.}. For the ESP, if you have one and assuming it is
2445 @file{/dev/sda1}, run:
2448 mkfs.fat -F32 /dev/sda1
2451 For the root file system, ext4 is the most widely used format. Other
2452 file systems, such as Btrfs, support compression, which is reported to
2453 nicely complement file deduplication that the daemon performs
2454 independently of the file system (@pxref{Invoking guix-daemon,
2457 Preferably, assign file systems a label so that you can easily and
2458 reliably refer to them in @code{file-system} declarations (@pxref{File
2459 Systems}). This is typically done using the @code{-L} option of
2460 @command{mkfs.ext4} and related commands. So, assuming the target root
2461 partition lives at @file{/dev/sda2}, a file system with the label
2462 @code{my-root} can be created with:
2465 mkfs.ext4 -L my-root /dev/sda2
2468 @cindex encrypted disk
2469 If you are instead planning to encrypt the root partition, you can use
2470 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2471 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2472 @code{man cryptsetup}} for more information). Assuming you want to
2473 store the root partition on @file{/dev/sda2}, the command sequence would
2474 be along these lines:
2477 cryptsetup luksFormat /dev/sda2
2478 cryptsetup open --type luks /dev/sda2 my-partition
2479 mkfs.ext4 -L my-root /dev/mapper/my-partition
2482 Once that is done, mount the target file system under @file{/mnt}
2483 with a command like (again, assuming @code{my-root} is the label of the
2487 mount LABEL=my-root /mnt
2490 Also mount any other file systems you would like to use on the target
2491 system relative to this path. If you have opted for @file{/boot/efi} as an
2492 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2493 found by @code{guix system init} afterwards.
2495 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2496 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2497 sure to initialize them with @command{mkswap}. Assuming you have one
2498 swap partition on @file{/dev/sda3}, you would run:
2505 Alternatively, you may use a swap file. For example, assuming that in
2506 the new system you want to use the file @file{/swapfile} as a swap file,
2507 you would run@footnote{This example will work for many types of file
2508 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2509 btrfs), the required steps may be different. For details, see the
2510 manual pages for @command{mkswap} and @command{swapon}.}:
2513 # This is 10 GiB of swap space. Adjust "count" to change the size.
2514 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2515 # For security, make the file readable and writable only by root.
2516 chmod 600 /mnt/swapfile
2517 mkswap /mnt/swapfile
2518 swapon /mnt/swapfile
2521 Note that if you have encrypted the root partition and created a swap
2522 file in its file system as described above, then the encryption also
2523 protects the swap file, just like any other file in that file system.
2525 @node Proceeding with the Installation
2526 @subsection Proceeding with the Installation
2528 With the target partitions ready and the target root mounted on
2529 @file{/mnt}, we're ready to go. First, run:
2532 herd start cow-store /mnt
2535 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2536 during the installation phase are written to the target disk on @file{/mnt}
2537 rather than kept in memory. This is necessary because the first phase of
2538 the @command{guix system init} command (see below) entails downloads or
2539 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2541 Next, you have to edit a file and
2542 provide the declaration of the operating system to be installed. To
2543 that end, the installation system comes with three text editors. We
2544 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2545 supports syntax highlighting and parentheses matching; other editors
2546 include GNU Zile (an Emacs clone), and
2547 nvi (a clone of the original BSD @command{vi} editor).
2548 We strongly recommend storing that file on the target root file system, say,
2549 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2550 configuration file once you have rebooted into the newly-installed system.
2552 @xref{Using the Configuration System}, for an overview of the
2553 configuration file. The example configurations discussed in that
2554 section are available under @file{/etc/configuration} in the
2555 installation image. Thus, to get started with a system configuration
2556 providing a graphical display server (a ``desktop'' system), you can run
2557 something along these lines:
2561 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2562 # nano /mnt/etc/config.scm
2565 You should pay attention to what your configuration file contains, and
2570 Make sure the @code{bootloader-configuration} form refers to the target
2571 you want to install GRUB on. It should mention @code{grub-bootloader} if
2572 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2573 for newer UEFI systems. For legacy systems, the @code{target} field
2574 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2575 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2576 currently mounted and a @code{file-system} entry is specified in your
2580 Be sure that your file system labels match the value of their respective
2581 @code{device} fields in your @code{file-system} configuration, assuming
2582 your @code{file-system} configuration uses the @code{file-system-label}
2583 procedure in its @code{device} field.
2586 If there are encrypted or RAID partitions, make sure to add a
2587 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2590 Once you are done preparing the configuration file, the new system must
2591 be initialized (remember that the target root file system is mounted
2595 guix system init /mnt/etc/config.scm /mnt
2599 This copies all the necessary files and installs GRUB on
2600 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2601 more information, @pxref{Invoking guix system}. This command may trigger
2602 downloads or builds of missing packages, which can take some time.
2604 Once that command has completed---and hopefully succeeded!---you can run
2605 @command{reboot} and boot into the new system. The @code{root} password
2606 in the new system is initially empty; other users' passwords need to be
2607 initialized by running the @command{passwd} command as @code{root},
2608 unless your configuration specifies otherwise
2609 (@pxref{user-account-password, user account passwords}).
2610 @xref{After System Installation}, for what's next!
2613 @node After System Installation
2614 @section After System Installation
2616 Success, you've now booted into Guix System! From then on, you can update the
2617 system whenever you want by running, say:
2621 sudo guix system reconfigure /etc/config.scm
2625 This builds a new system generation with the latest packages and services
2626 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2627 your system includes the latest security updates (@pxref{Security Updates}).
2629 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2631 @cindex sudo vs. @command{guix pull}
2632 Note that @command{sudo guix} runs your user's @command{guix} command and
2633 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2634 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2636 The difference matters here, because @command{guix pull} updates
2637 the @command{guix} command and package definitions only for the user it is run
2638 as. This means that if you choose to use @command{guix system reconfigure} in
2639 root's login shell, you'll need to @command{guix pull} separately.
2642 Now, @pxref{Getting Started}, and
2643 join us on @code{#guix} on the Libera Chat IRC network or on
2644 @email{guix-devel@@gnu.org} to share your experience!
2647 @node Installing Guix in a VM
2648 @section Installing Guix in a Virtual Machine
2650 @cindex virtual machine, Guix System installation
2651 @cindex virtual private server (VPS)
2652 @cindex VPS (virtual private server)
2653 If you'd like to install Guix System in a virtual machine (VM) or on a
2654 virtual private server (VPS) rather than on your beloved machine, this
2657 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2658 disk image, follow these steps:
2662 First, retrieve and decompress the Guix system installation image as
2663 described previously (@pxref{USB Stick and DVD Installation}).
2666 Create a disk image that will hold the installed system. To make a
2667 qcow2-formatted disk image, use the @command{qemu-img} command:
2670 qemu-img create -f qcow2 guix-system.img 50G
2673 The resulting file will be much smaller than 50 GB (typically less than
2674 1 MB), but it will grow as the virtualized storage device is filled up.
2677 Boot the USB installation image in an VM:
2680 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2681 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2682 -drive file=guix-system.img \
2683 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2686 @code{-enable-kvm} is optional, but significantly improves performance,
2687 @pxref{Running Guix in a VM}.
2690 You're now root in the VM, proceed with the installation process.
2691 @xref{Preparing for Installation}, and follow the instructions.
2694 Once installation is complete, you can boot the system that's on your
2695 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2698 @node Building the Installation Image
2699 @section Building the Installation Image
2701 @cindex installation image
2702 The installation image described above was built using the @command{guix
2703 system} command, specifically:
2706 guix system image -t iso9660 gnu/system/install.scm
2709 Have a look at @file{gnu/system/install.scm} in the source tree,
2710 and see also @ref{Invoking guix system} for more information
2711 about the installation image.
2713 @section Building the Installation Image for ARM Boards
2715 Many ARM boards require a specific variant of the
2716 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2718 If you build a disk image and the bootloader is not available otherwise
2719 (on another boot drive etc), it's advisable to build an image that
2720 includes the bootloader, specifically:
2723 guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2726 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2727 board, a list of possible boards will be printed.
2729 @c *********************************************************************
2730 @node Getting Started
2731 @chapter Getting Started
2733 Presumably, you've reached this section because either you have
2734 installed Guix on top of another distribution (@pxref{Installation}), or
2735 you've installed the standalone Guix System (@pxref{System
2736 Installation}). It's time for you to get started using Guix and this
2737 section aims to help you do that and give you a feel of what it's like.
2739 Guix is about installing software, so probably the first thing you'll
2740 want to do is to actually look for software. Let's say you're looking
2741 for a text editor, you can run:
2744 guix search text editor
2747 This command shows you a number of matching @dfn{packages}, each time
2748 showing the package's name, version, a description, and additional info.
2749 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2750 you can go ahead and install it (run this command as a regular user,
2751 @emph{no need for root privileges}!):
2758 You've installed your first package, congrats! The package is now
2759 visible in your default @dfn{profile}, @file{$HOME/.guix-profile}---a
2760 profile is a directory containing installed packages.
2761 In the process, you've
2762 probably noticed that Guix downloaded pre-built binaries; or, if you
2763 explicitly chose to @emph{not} use pre-built binaries, then probably
2764 Guix is still building software (@pxref{Substitutes}, for more info).
2766 Unless you're using Guix System, the @command{guix install} command must
2767 have printed this hint:
2770 hint: Consider setting the necessary environment variables by running:
2772 GUIX_PROFILE="$HOME/.guix-profile"
2773 . "$GUIX_PROFILE/etc/profile"
2775 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2778 Indeed, you must now tell your shell where @command{emacs} and other
2779 programs installed with Guix are to be found. Pasting the two lines
2780 above will do just that: it will add
2781 @code{$HOME/.guix-profile/bin}---which is where the installed package
2782 is---to the @code{PATH} environment variable. You can paste these two
2783 lines in your shell so they take effect right away, but more importantly
2784 you should add them to @file{~/.bash_profile} (or equivalent file if you
2785 do not use Bash) so that environment variables are set next time you
2786 spawn a shell. You only need to do this once and other search paths
2787 environment variables will be taken care of similarly---e.g., if you
2788 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2791 You can go on installing packages at your will. To list installed
2795 guix package --list-installed
2798 To remove a package, you would unsurprisingly run @command{guix remove}.
2799 A distinguishing feature is the ability to @dfn{roll back} any operation
2800 you made---installation, removal, upgrade---by simply typing:
2803 guix package --roll-back
2806 This is because each operation is in fact a @dfn{transaction} that
2807 creates a new @dfn{generation}. These generations and the difference
2808 between them can be displayed by running:
2811 guix package --list-generations
2814 Now you know the basics of package management!
2816 @quotation Going further
2817 @xref{Package Management}, for more about package management. You may
2818 like @dfn{declarative} package management with @command{guix package
2819 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2820 deleting old generations, collecting garbage, and other nifty features
2821 that will come in handy as you become more familiar with Guix. If you
2822 are a developer, @pxref{Development} for additional tools. And if
2823 you're curious, @pxref{Features}, to peek under the hood.
2826 Once you've installed a set of packages, you will want to periodically
2827 @emph{upgrade} them to the latest and greatest version. To do that, you
2828 will first pull the latest revision of Guix and its package collection:
2834 The end result is a new @command{guix} command, under
2835 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2836 first time you run @command{guix pull}, be sure to follow the hint that
2837 the command prints and, similar to what we saw above, paste these two
2838 lines in your terminal and @file{.bash_profile}:
2841 GUIX_PROFILE="$HOME/.config/guix/current"
2842 . "$GUIX_PROFILE/etc/profile"
2846 You must also instruct your shell to point to this new @command{guix}:
2852 At this point, you're running a brand new Guix. You can thus go ahead
2853 and actually upgrade all the packages you previously installed:
2859 As you run this command, you will see that binaries are downloaded (or
2860 perhaps some packages are built), and eventually you end up with the
2861 upgraded packages. Should one of these upgraded packages not be to your
2862 liking, remember you can always roll back!
2864 You can display the exact revision of Guix you're currently using by
2871 The information it displays is @emph{all it takes to reproduce the exact
2872 same Guix}, be it at a different point in time or on a different
2875 @quotation Going further
2876 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2877 how to specify additional @dfn{channels} to pull packages from, how to
2878 replicate Guix, and more. You may also find @command{time-machine}
2879 handy (@pxref{Invoking guix time-machine}).
2882 If you installed Guix System, one of the first things you'll want to do
2883 is to upgrade your system. Once you've run @command{guix pull} to get
2884 the latest Guix, you can upgrade the system like this:
2887 sudo guix system reconfigure /etc/config.scm
2890 Upon completion, the system runs the latest versions of its software
2891 packages. When you eventually reboot, you'll notice a sub-menu in the
2892 bootloader that reads ``Old system generations'': it's what allows you
2893 to boot @emph{an older generation of your system}, should the latest
2894 generation be ``broken'' or otherwise unsatisfying. Just like for
2895 packages, you can always @emph{roll back} to a previous generation
2896 @emph{of the whole system}:
2899 sudo guix system roll-back
2902 There are many things you'll probably want to tweak on your system:
2903 adding new user accounts, adding new system services, fiddling with the
2904 configuration of those services, etc. The system configuration is
2905 @emph{entirely} described in the @file{/etc/config.scm} file.
2906 @xref{Using the Configuration System}, to learn how to change it.
2908 Now you know enough to get started!
2910 @quotation Resources
2911 The rest of this manual provides a reference for all things Guix. Here
2912 are some additional resources you may find useful:
2916 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2917 ``how-to'' style of recipes for a variety of applications.
2920 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2921 Card} lists in two pages most of the commands and options you'll ever
2925 The web site contains @uref{https://guix.gnu.org/en/videos/,
2926 instructional videos} covering topics such as everyday use of Guix, how
2927 to get help, and how to become a contributor.
2930 @xref{Documentation}, to learn how to access documentation on your
2934 We hope you will enjoy Guix as much as the community enjoys building it!
2937 @c *********************************************************************
2938 @node Package Management
2939 @chapter Package Management
2942 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2943 remove software packages, without having to know about their build
2944 procedures or dependencies. Guix also goes beyond this obvious set of
2947 This chapter describes the main features of Guix, as well as the
2948 package management tools it provides. Along with the command-line
2949 interface described below (@pxref{Invoking guix package, @code{guix
2950 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2951 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2952 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2956 guix install emacs-guix
2960 * Features:: How Guix will make your life brighter.
2961 * Invoking guix package:: Package installation, removal, etc.
2962 * Substitutes:: Downloading pre-built binaries.
2963 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2964 * Invoking guix gc:: Running the garbage collector.
2965 * Invoking guix pull:: Fetching the latest Guix and distribution.
2966 * Invoking guix time-machine:: Running an older revision of Guix.
2967 * Inferiors:: Interacting with another revision of Guix.
2968 * Invoking guix describe:: Display information about your Guix revision.
2969 * Invoking guix archive:: Exporting and importing store files.
2975 Here we assume you've already made your first steps with Guix
2976 (@pxref{Getting Started}) and would like to get an overview about what's
2977 going on under the hood.
2979 When using Guix, each package ends up in the @dfn{package store}, in its
2980 own directory---something that resembles
2981 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2983 Instead of referring to these directories, users have their own
2984 @dfn{profile}, which points to the packages that they actually want to
2985 use. These profiles are stored within each user's home directory, at
2986 @code{$HOME/.guix-profile}.
2988 For example, @code{alice} installs GCC 4.7.2. As a result,
2989 @file{/home/alice/.guix-profile/bin/gcc} points to
2990 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2991 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2992 simply continues to point to
2993 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2994 coexist on the same system without any interference.
2996 The @command{guix package} command is the central tool to manage
2997 packages (@pxref{Invoking guix package}). It operates on the per-user
2998 profiles, and can be used @emph{with normal user privileges}.
3000 @cindex transactions
3001 The command provides the obvious install, remove, and upgrade
3002 operations. Each invocation is actually a @emph{transaction}: either
3003 the specified operation succeeds, or nothing happens. Thus, if the
3004 @command{guix package} process is terminated during the transaction,
3005 or if a power outage occurs during the transaction, then the user's
3006 profile remains in its previous state, and remains usable.
3008 In addition, any package transaction may be @emph{rolled back}. So, if,
3009 for example, an upgrade installs a new version of a package that turns
3010 out to have a serious bug, users may roll back to the previous instance
3011 of their profile, which was known to work well. Similarly, the global
3012 system configuration on Guix is subject to
3013 transactional upgrades and roll-back
3014 (@pxref{Using the Configuration System}).
3016 All packages in the package store may be @emph{garbage-collected}.
3017 Guix can determine which packages are still referenced by user
3018 profiles, and remove those that are provably no longer referenced
3019 (@pxref{Invoking guix gc}). Users may also explicitly remove old
3020 generations of their profile so that the packages they refer to can be
3023 @cindex reproducibility
3024 @cindex reproducible builds
3025 Guix takes a @dfn{purely functional} approach to package
3026 management, as described in the introduction (@pxref{Introduction}).
3027 Each @file{/gnu/store} package directory name contains a hash of all the
3028 inputs that were used to build that package---compiler, libraries, build
3029 scripts, etc. This direct correspondence allows users to make sure a
3030 given package installation matches the current state of their
3031 distribution. It also helps maximize @dfn{build reproducibility}:
3032 thanks to the isolated build environments that are used, a given build
3033 is likely to yield bit-identical files when performed on different
3034 machines (@pxref{Invoking guix-daemon, container}).
3037 This foundation allows Guix to support @dfn{transparent binary/source
3038 deployment}. When a pre-built binary for a @file{/gnu/store} item is
3039 available from an external source---a @dfn{substitute}, Guix just
3040 downloads it and unpacks it;
3041 otherwise, it builds the package from source, locally
3042 (@pxref{Substitutes}). Because build results are usually bit-for-bit
3043 reproducible, users do not have to trust servers that provide
3044 substitutes: they can force a local build and @emph{challenge} providers
3045 (@pxref{Invoking guix challenge}).
3047 Control over the build environment is a feature that is also useful for
3048 developers. The @command{guix environment} command allows developers of
3049 a package to quickly set up the right development environment for their
3050 package, without having to manually install the dependencies of the
3051 package into their profile (@pxref{Invoking guix environment}).
3053 @cindex replication, of software environments
3054 @cindex provenance tracking, of software artifacts
3055 All of Guix and its package definitions is version-controlled, and
3056 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3057 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3058 Guix instance on a different machine or at a later point in time, which in
3059 turn allows you to @emph{replicate complete software environments}, while
3060 retaining precise @dfn{provenance tracking} of the software.
3062 @node Invoking guix package
3063 @section Invoking @command{guix package}
3065 @cindex installing packages
3066 @cindex removing packages
3067 @cindex package installation
3068 @cindex package removal
3070 The @command{guix package} command is the tool that allows users to
3071 install, upgrade, and remove packages, as well as rolling back to
3072 previous configurations. These operations work on a user
3073 @dfn{profile}---a directory of installed packages. Each user has a
3074 default profile in @file{$HOME/.guix-profile}.
3075 The command operates only on the user's own profile,
3076 and works with normal user privileges (@pxref{Features}). Its syntax
3080 guix package @var{options}
3083 @cindex transactions
3084 Primarily, @var{options} specifies the operations to be performed during
3085 the transaction. Upon completion, a new profile is created, but
3086 previous @dfn{generations} of the profile remain available, should the user
3089 For example, to remove @code{lua} and install @code{guile} and
3090 @code{guile-cairo} in a single transaction:
3093 guix package -r lua -i guile guile-cairo
3096 @cindex aliases, for @command{guix package}
3097 For your convenience, we also provide the following aliases:
3101 @command{guix search} is an alias for @command{guix package -s},
3103 @command{guix install} is an alias for @command{guix package -i},
3105 @command{guix remove} is an alias for @command{guix package -r},
3107 @command{guix upgrade} is an alias for @command{guix package -u},
3109 and @command{guix show} is an alias for @command{guix package --show=}.
3112 These aliases are less expressive than @command{guix package} and provide
3113 fewer options, so in some cases you'll probably want to use @command{guix
3116 @command{guix package} also supports a @dfn{declarative approach}
3117 whereby the user specifies the exact set of packages to be available and
3118 passes it @i{via} the @option{--manifest} option
3119 (@pxref{profile-manifest, @option{--manifest}}).
3122 For each user, a symlink to the user's default profile is automatically
3123 created in @file{$HOME/.guix-profile}. This symlink always points to the
3124 current generation of the user's default profile. Thus, users can add
3125 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3126 variable, and so on.
3127 @cindex search paths
3128 If you are not using Guix System, consider adding the
3129 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3130 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3131 shells get all the right environment variable definitions:
3134 GUIX_PROFILE="$HOME/.guix-profile" ; \
3135 source "$GUIX_PROFILE/etc/profile"
3138 In a multi-user setup, user profiles are stored in a place registered as
3139 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3140 to (@pxref{Invoking guix gc}). That directory is normally
3141 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3142 @var{localstatedir} is the value passed to @code{configure} as
3143 @option{--localstatedir}, and @var{user} is the user name. The
3144 @file{per-user} directory is created when @command{guix-daemon} is
3145 started, and the @var{user} sub-directory is created by @command{guix
3148 The @var{options} can be among the following:
3152 @item --install=@var{package} @dots{}
3153 @itemx -i @var{package} @dots{}
3154 Install the specified @var{package}s.
3156 Each @var{package} may specify either a simple package name, such as
3157 @code{guile}, or a package name followed by an at-sign and version number,
3158 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3159 case, the newest version prefixed by @code{1.8} is selected).
3161 If no version number is specified, the
3162 newest available version will be selected. In addition, @var{package}
3163 may contain a colon, followed by the name of one of the outputs of the
3164 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3165 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3166 name (and optionally version) are searched for among the GNU
3167 distribution modules (@pxref{Package Modules}).
3169 @cindex propagated inputs
3170 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3171 that automatically get installed along with the required package
3172 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3173 @code{package} objects}, for information about propagated inputs in
3174 package definitions).
3176 @anchor{package-cmd-propagated-inputs}
3177 An example is the GNU MPC library: its C header files refer to those of
3178 the GNU MPFR library, which in turn refer to those of the GMP library.
3179 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3180 in the profile; removing MPC also removes MPFR and GMP---unless they had
3181 also been explicitly installed by the user.
3183 Besides, packages sometimes rely on the definition of environment
3184 variables for their search paths (see explanation of
3185 @option{--search-paths} below). Any missing or possibly incorrect
3186 environment variable definitions are reported here.
3188 @item --install-from-expression=@var{exp}
3190 Install the package @var{exp} evaluates to.
3192 @var{exp} must be a Scheme expression that evaluates to a
3193 @code{<package>} object. This option is notably useful to disambiguate
3194 between same-named variants of a package, with expressions such as
3195 @code{(@@ (gnu packages base) guile-final)}.
3197 Note that this option installs the first output of the specified
3198 package, which may be insufficient when needing a specific output of a
3199 multiple-output package.
3201 @item --install-from-file=@var{file}
3202 @itemx -f @var{file}
3203 Install the package that the code within @var{file} evaluates to.
3205 As an example, @var{file} might contain a definition like this
3206 (@pxref{Defining Packages}):
3209 @include package-hello.scm
3212 Developers may find it useful to include such a @file{guix.scm} file
3213 in the root of their project source tree that can be used to test
3214 development snapshots and create reproducible development environments
3215 (@pxref{Invoking guix environment}).
3217 The @var{file} may also contain a JSON representation of one or more
3218 package definitions. Running @code{guix package -f} on
3219 @file{hello.json} with the following contents would result in installing
3220 the package @code{greeter} after building @code{myhello}:
3223 @verbatiminclude package-hello.json
3226 @item --remove=@var{package} @dots{}
3227 @itemx -r @var{package} @dots{}
3228 Remove the specified @var{package}s.
3230 As for @option{--install}, each @var{package} may specify a version number
3231 and/or output name in addition to the package name. For instance,
3232 @samp{-r glibc:debug} would remove the @code{debug} output of
3235 @item --upgrade[=@var{regexp} @dots{}]
3236 @itemx -u [@var{regexp} @dots{}]
3237 @cindex upgrading packages
3238 Upgrade all the installed packages. If one or more @var{regexp}s are
3239 specified, upgrade only installed packages whose name matches a
3240 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3242 Note that this upgrades package to the latest version of packages found
3243 in the distribution currently installed. To update your distribution,
3244 you should regularly run @command{guix pull} (@pxref{Invoking guix
3247 @cindex package transformations, upgrades
3248 When upgrading, package transformations that were originally applied
3249 when creating the profile are automatically re-applied (@pxref{Package
3250 Transformation Options}). For example, assume you first installed Emacs
3251 from the tip of its development branch with:
3254 guix install emacs-next --with-branch=emacs-next=master
3257 Next time you run @command{guix upgrade}, Guix will again pull the tip
3258 of the Emacs development branch and build @code{emacs-next} from that
3261 Note that transformation options such as @option{--with-branch} and
3262 @option{--with-source} depend on external state; it is up to you to
3263 ensure that they work as expected. You can also discard a
3264 transformations that apply to a package by running:
3267 guix install @var{package}
3270 @item --do-not-upgrade[=@var{regexp} @dots{}]
3271 When used together with the @option{--upgrade} option, do @emph{not}
3272 upgrade any packages whose name matches a @var{regexp}. For example, to
3273 upgrade all packages in the current profile except those containing the
3274 substring ``emacs'':
3277 $ guix package --upgrade . --do-not-upgrade emacs
3280 @item @anchor{profile-manifest}--manifest=@var{file}
3281 @itemx -m @var{file}
3282 @cindex profile declaration
3283 @cindex profile manifest
3284 Create a new generation of the profile from the manifest object
3285 returned by the Scheme code in @var{file}. This option can be repeated
3286 several times, in which case the manifests are concatenated.
3288 This allows you to @emph{declare} the profile's contents rather than
3289 constructing it through a sequence of @option{--install} and similar
3290 commands. The advantage is that @var{file} can be put under version
3291 control, copied to different machines to reproduce the same profile, and
3294 @c FIXME: Add reference to (guix profile) documentation when available.
3295 @var{file} must return a @dfn{manifest} object, which is roughly a list
3298 @findex packages->manifest
3300 (use-package-modules guile emacs)
3305 ;; Use a specific package output.
3306 (list guile-2.0 "debug")))
3309 @findex specifications->manifest
3310 In this example we have to know which modules define the @code{emacs}
3311 and @code{guile-2.0} variables to provide the right
3312 @code{use-package-modules} line, which can be cumbersome. We can
3313 instead provide regular package specifications and let
3314 @code{specifications->manifest} look up the corresponding package
3318 (specifications->manifest
3319 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3322 @xref{export-manifest, @option{--export-manifest}}, to learn how to
3323 obtain a manifest file from an existing profile.
3326 @cindex rolling back
3327 @cindex undoing transactions
3328 @cindex transactions, undoing
3329 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3330 the last transaction.
3332 When combined with options such as @option{--install}, roll back occurs
3333 before any other actions.
3335 When rolling back from the first generation that actually contains
3336 installed packages, the profile is made to point to the @dfn{zeroth
3337 generation}, which contains no files apart from its own metadata.
3339 After having rolled back, installing, removing, or upgrading packages
3340 overwrites previous future generations. Thus, the history of the
3341 generations in a profile is always linear.
3343 @item --switch-generation=@var{pattern}
3344 @itemx -S @var{pattern}
3346 Switch to a particular generation defined by @var{pattern}.
3348 @var{pattern} may be either a generation number or a number prefixed
3349 with ``+'' or ``-''. The latter means: move forward/backward by a
3350 specified number of generations. For example, if you want to return to
3351 the latest generation after @option{--roll-back}, use
3352 @option{--switch-generation=+1}.
3354 The difference between @option{--roll-back} and
3355 @option{--switch-generation=-1} is that @option{--switch-generation} will
3356 not make a zeroth generation, so if a specified generation does not
3357 exist, the current generation will not be changed.
3359 @item --search-paths[=@var{kind}]
3360 @cindex search paths
3361 Report environment variable definitions, in Bash syntax, that may be
3362 needed in order to use the set of installed packages. These environment
3363 variables are used to specify @dfn{search paths} for files used by some
3364 of the installed packages.
3366 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3367 environment variables to be defined so it can look for headers and
3368 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3369 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3370 library are installed in the profile, then @option{--search-paths} will
3371 suggest setting these variables to @file{@var{profile}/include} and
3372 @file{@var{profile}/lib}, respectively.
3374 The typical use case is to define these environment variables in the
3378 $ eval `guix package --search-paths`
3381 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3382 meaning that the returned environment variable definitions will either
3383 be exact settings, or prefixes or suffixes of the current value of these
3384 variables. When omitted, @var{kind} defaults to @code{exact}.
3386 This option can also be used to compute the @emph{combined} search paths
3387 of several profiles. Consider this example:
3390 $ guix package -p foo -i guile
3391 $ guix package -p bar -i guile-json
3392 $ guix package -p foo -p bar --search-paths
3395 The last command above reports about the @env{GUILE_LOAD_PATH}
3396 variable, even though, taken individually, neither @file{foo} nor
3397 @file{bar} would lead to that recommendation.
3400 @cindex profile, choosing
3401 @item --profile=@var{profile}
3402 @itemx -p @var{profile}
3403 Use @var{profile} instead of the user's default profile.
3405 @var{profile} must be the name of a file that will be created upon
3406 completion. Concretely, @var{profile} will be a mere symbolic link
3407 (``symlink'') pointing to the actual profile where packages are
3411 $ guix install hello -p ~/code/my-profile
3413 $ ~/code/my-profile/bin/hello
3417 All it takes to get rid of the profile is to remove this symlink and its
3418 siblings that point to specific generations:
3421 $ rm ~/code/my-profile ~/code/my-profile-*-link
3424 @item --list-profiles
3425 List all the user's profiles:
3428 $ guix package --list-profiles
3429 /home/charlie/.guix-profile
3430 /home/charlie/code/my-profile
3431 /home/charlie/code/devel-profile
3432 /home/charlie/tmp/test
3435 When running as root, list all the profiles of all the users.
3437 @cindex collisions, in a profile
3438 @cindex colliding packages in profiles
3439 @cindex profile collisions
3440 @item --allow-collisions
3441 Allow colliding packages in the new profile. Use at your own risk!
3443 By default, @command{guix package} reports as an error @dfn{collisions}
3444 in the profile. Collisions happen when two or more different versions
3445 or variants of a given package end up in the profile.
3448 Use the bootstrap Guile to build the profile. This option is only
3449 useful to distribution developers.
3453 In addition to these actions, @command{guix package} supports the
3454 following options to query the current state of a profile, or the
3455 availability of packages:
3459 @item --search=@var{regexp}
3460 @itemx -s @var{regexp}
3461 @anchor{guix-search}
3462 @cindex searching for packages
3463 List the available packages whose name, synopsis, or description matches
3464 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3465 Print all the metadata of matching packages in
3466 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3467 GNU recutils manual}).
3469 This allows specific fields to be extracted using the @command{recsel}
3470 command, for instance:
3473 $ guix package -s malloc | recsel -p name,version,relevance
3487 Similarly, to show the name of all the packages available under the
3488 terms of the GNU@tie{}LGPL version 3:
3491 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3498 It is also possible to refine search results using several @code{-s} flags to
3499 @command{guix package}, or several arguments to @command{guix search}. For
3500 example, the following command returns a list of board games (this time using
3501 the @command{guix search} alias):
3504 $ guix search '\<board\>' game | recsel -p name
3509 If we were to omit @code{-s game}, we would also get software packages
3510 that deal with printed circuit boards; removing the angle brackets
3511 around @code{board} would further add packages that have to do with
3514 And now for a more elaborate example. The following command searches
3515 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3516 libraries, and prints the name and synopsis of the matching packages:
3519 $ guix search crypto library | \
3520 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3524 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3525 information on @dfn{selection expressions} for @code{recsel -e}.
3527 @item --show=@var{package}
3528 Show details about @var{package}, taken from the list of available packages, in
3529 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3533 $ guix package --show=python | recsel -p name,version
3541 You may also specify the full name of a package to only get details about a
3542 specific version of it (this time using the @command{guix show} alias):
3544 $ guix show python@@3.4 | recsel -p name,version
3551 @item --list-installed[=@var{regexp}]
3552 @itemx -I [@var{regexp}]
3553 List the currently installed packages in the specified profile, with the
3554 most recently installed packages shown last. When @var{regexp} is
3555 specified, list only installed packages whose name matches @var{regexp}.
3557 For each installed package, print the following items, separated by
3558 tabs: the package name, its version string, the part of the package that
3559 is installed (for instance, @code{out} for the default output,
3560 @code{include} for its headers, etc.), and the path of this package in
3563 @item --list-available[=@var{regexp}]
3564 @itemx -A [@var{regexp}]
3565 List packages currently available in the distribution for this system
3566 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3567 available packages whose name matches @var{regexp}.
3569 For each package, print the following items separated by tabs: its name,
3570 its version string, the parts of the package (@pxref{Packages with
3571 Multiple Outputs}), and the source location of its definition.
3573 @item --list-generations[=@var{pattern}]
3574 @itemx -l [@var{pattern}]
3576 Return a list of generations along with their creation dates; for each
3577 generation, show the installed packages, with the most recently
3578 installed packages shown last. Note that the zeroth generation is never
3581 For each installed package, print the following items, separated by
3582 tabs: the name of a package, its version string, the part of the package
3583 that is installed (@pxref{Packages with Multiple Outputs}), and the
3584 location of this package in the store.
3586 When @var{pattern} is used, the command returns only matching
3587 generations. Valid patterns include:
3590 @item @emph{Integers and comma-separated integers}. Both patterns denote
3591 generation numbers. For instance, @option{--list-generations=1} returns
3594 And @option{--list-generations=1,8,2} outputs three generations in the
3595 specified order. Neither spaces nor trailing commas are allowed.
3597 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3598 specified generations and everything in between. Note that the start of
3599 a range must be smaller than its end.
3601 It is also possible to omit the endpoint. For example,
3602 @option{--list-generations=2..}, returns all generations starting from the
3605 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3606 or months by passing an integer along with the first letter of the
3607 duration. For example, @option{--list-generations=20d} lists generations
3608 that are up to 20 days old.
3611 @item --delete-generations[=@var{pattern}]
3612 @itemx -d [@var{pattern}]
3613 When @var{pattern} is omitted, delete all generations except the current
3616 This command accepts the same patterns as @option{--list-generations}.
3617 When @var{pattern} is specified, delete the matching generations. When
3618 @var{pattern} specifies a duration, generations @emph{older} than the
3619 specified duration match. For instance, @option{--delete-generations=1m}
3620 deletes generations that are more than one month old.
3622 If the current generation matches, it is @emph{not} deleted. Also, the
3623 zeroth generation is never deleted.
3625 Note that deleting generations prevents rolling back to them.
3626 Consequently, this command must be used with care.
3628 @cindex manifest, exporting
3629 @anchor{export-manifest}
3630 @item --export-manifest
3631 Write to standard output a manifest suitable for @option{--manifest}
3632 corresponding to the chosen profile(s).
3634 This option is meant to help you migrate from the ``imperative''
3635 operating mode---running @command{guix install}, @command{guix upgrade},
3636 etc.---to the declarative mode that @option{--manifest} offers.
3638 Be aware that the resulting manifest @emph{approximates} what your
3639 profile actually contains; for instance, depending on how your profile
3640 was created, it can refer to packages or package versions that are not
3641 exactly what you specified.
3643 Keep in mind that a manifest is purely symbolic: it only contains
3644 package names and possibly versions, and their meaning varies over time.
3645 If you wish to ``pin'' channels to the revisions that were used to build
3646 the profile(s), see @option{--export-channels} below.
3648 @cindex pinning, channel revisions of a profile
3649 @item --export-channels
3650 Write to standard output the list of channels used by the chosen
3651 profile(s), in a format suitable for @command{guix pull --channels} or
3652 @command{guix time-machine --channels} (@pxref{Channels}).
3654 Together with @option{--export-manifest}, this option provides
3655 information allowing you to replicate the current profile
3656 (@pxref{Replicating Guix}).
3658 However, note that the output of this command @emph{approximates} what
3659 was actually used to build this profile. In particular, a single
3660 profile might have been built from several different revisions of the
3661 same channel. In that case, @option{--export-manifest} chooses the last
3662 one and writes the list of other revisions in a comment. If you really
3663 need to pick packages from different channel revisions, you can use
3664 inferiors in your manifest to do so (@pxref{Inferiors}).
3666 Together with @option{--export-manifest}, this is a good starting point
3667 if you are willing to migrate from the ``imperative'' model to the fully
3668 declarative model consisting of a manifest file along with a channels
3669 file pinning the exact channel revision(s) you want.
3672 Finally, since @command{guix package} may actually start build
3673 processes, it supports all the common build options (@pxref{Common Build
3674 Options}). It also supports package transformation options, such as
3675 @option{--with-source}, and preserves them across upgrades
3676 (@pxref{Package Transformation Options}).
3679 @section Substitutes
3682 @cindex pre-built binaries
3683 Guix supports transparent source/binary deployment, which means that it
3684 can either build things locally, or download pre-built items from a
3685 server, or both. We call these pre-built items @dfn{substitutes}---they
3686 are substitutes for local build results. In many cases, downloading a
3687 substitute is much faster than building things locally.
3689 Substitutes can be anything resulting from a derivation build
3690 (@pxref{Derivations}). Of course, in the common case, they are
3691 pre-built package binaries, but source tarballs, for instance, which
3692 also result from derivation builds, can be available as substitutes.
3695 * Official Substitute Servers:: One particular source of substitutes.
3696 * Substitute Server Authorization:: How to enable or disable substitutes.
3697 * Getting Substitutes from Other Servers:: Substitute diversity.
3698 * Substitute Authentication:: How Guix verifies substitutes.
3699 * Proxy Settings:: How to get substitutes via proxy.
3700 * Substitution Failure:: What happens when substitution fails.
3701 * On Trusting Binaries:: How can you trust that binary blob?
3704 @node Official Substitute Servers
3705 @subsection Official Substitute Servers
3708 @code{@value{SUBSTITUTE-SERVER-1}} and
3709 @code{@value{SUBSTITUTE-SERVER-2}} are both front-ends to official build
3710 farms that build packages from Guix continuously for some architectures,
3711 and make them available as substitutes. These are the default source of
3712 substitutes; which can be overridden by passing the
3713 @option{--substitute-urls} option either to @command{guix-daemon}
3714 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3715 or to client tools such as @command{guix package}
3716 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3719 Substitute URLs can be either HTTP or HTTPS.
3720 HTTPS is recommended because communications are encrypted; conversely,
3721 using HTTP makes all communications visible to an eavesdropper, who
3722 could use the information gathered to determine, for instance, whether
3723 your system has unpatched security vulnerabilities.
3725 Substitutes from the official build farms are enabled by default when
3726 using Guix System (@pxref{GNU Distribution}). However,
3727 they are disabled by default when using Guix on a foreign distribution,
3728 unless you have explicitly enabled them via one of the recommended
3729 installation steps (@pxref{Installation}). The following paragraphs
3730 describe how to enable or disable substitutes for the official build
3731 farm; the same procedure can also be used to enable substitutes for any
3732 other substitute server.
3734 @node Substitute Server Authorization
3735 @subsection Substitute Server Authorization
3738 @cindex substitutes, authorization thereof
3739 @cindex access control list (ACL), for substitutes
3740 @cindex ACL (access control list), for substitutes
3741 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER-1}}, @code{@value{SUBSTITUTE-SERVER-2}} or a mirror, you
3742 must add the relevant public key to the access control list (ACL) of archive
3743 imports, using the @command{guix archive} command (@pxref{Invoking guix
3744 archive}). Doing so implies that you trust the substitute server to not
3745 be compromised and to serve genuine substitutes.
3748 If you are using Guix System, you can skip this section: Guix System
3749 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER-1}} and
3750 @code{@value{SUBSTITUTE-SERVER-2}} by default.
3753 The public keys for each of the project maintained substitute servers
3754 are installed along with Guix, in @code{@var{prefix}/share/guix/}, where
3755 @var{prefix} is the installation prefix of Guix. If you installed Guix
3756 from source, make sure you checked the GPG signature of
3757 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3758 Then, you can run something like this:
3761 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER-1}.pub
3762 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER-2}.pub
3765 Once this is in place, the output of a command like @code{guix build}
3766 should change from something like:
3769 $ guix build emacs --dry-run
3770 The following derivations would be built:
3771 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3772 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3773 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3774 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3782 $ guix build emacs --dry-run
3783 112.3 MB would be downloaded:
3784 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3785 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3786 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3787 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3792 The text changed from ``The following derivations would be built'' to
3793 ``112.3 MB would be downloaded''. This indicates that substitutes from
3794 the configured substitute servers are usable and will be downloaded,
3795 when possible, for future builds.
3797 @cindex substitutes, how to disable
3798 The substitute mechanism can be disabled globally by running
3799 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3800 guix-daemon}). It can also be disabled temporarily by passing the
3801 @option{--no-substitutes} option to @command{guix package},
3802 @command{guix build}, and other command-line tools.
3804 @node Getting Substitutes from Other Servers
3805 @subsection Getting Substitutes from Other Servers
3807 @cindex substitute servers, adding more
3808 Guix can look up and fetch substitutes from several servers. This is
3809 useful when you are using packages from additional channels for which
3810 the official server does not have substitutes but another server
3811 provides them. Another situation where this is useful is when you would
3812 prefer to download from your organization's substitute server, resorting
3813 to the official server only as a fallback or dismissing it altogether.
3815 You can give Guix a list of substitute server URLs and it will check
3816 them in the specified order. You also need to explicitly authorize the
3817 public keys of substitute servers to instruct Guix to accept the
3818 substitutes they sign.
3820 On Guix System, this is achieved by modifying the configuration of the
3821 @code{guix} service. Since the @code{guix} service is part of the
3822 default lists of services, @code{%base-services} and
3823 @code{%desktop-services}, you can use @code{modify-services} to change
3824 its configuration and add the URLs and substitute keys that you want
3825 (@pxref{Service Reference, @code{modify-services}}).
3827 As an example, suppose you want to fetch substitutes from
3828 @code{guix.example.org} and to authorize the signing key of that server,
3829 in addition to the default @code{@value{SUBSTITUTE-SERVER-1}} and
3830 @code{@value{SUBSTITUTE-SERVER-2}}. The resulting operating system
3831 configuration will look something like:
3837 ;; Assume we're starting from '%desktop-services'. Replace it
3838 ;; with the list of services you're actually using.
3839 (modify-services %desktop-services
3840 (guix-service-type config =>
3844 (append (list "https://guix.example.org")
3845 %default-substitute-urls))
3847 (append (list (local-file "./key.pub"))
3848 %default-authorized-guix-keys)))))))
3851 This assumes that the file @file{key.pub} contains the signing key of
3852 @code{guix.example.org}. With this change in place in your operating
3853 system configuration file (say @file{/etc/config.scm}), you can
3854 reconfigure and restart the @code{guix-daemon} service or reboot so the
3855 changes take effect:
3858 $ sudo guix system reconfigure /etc/config.scm
3859 $ sudo herd restart guix-daemon
3862 If you're running Guix on a ``foreign distro'', you would instead take
3863 the following steps to get substitutes from additional servers:
3867 Edit the service configuration file for @code{guix-daemon}; when using
3868 systemd, this is normally
3869 @file{/etc/systemd/system/guix-daemon.service}. Add the
3870 @option{--substitute-urls} option on the @command{guix-daemon} command
3871 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3872 @code{guix-daemon --substitute-urls}}):
3875 @dots{} --substitute-urls='https://guix.example.org @value{SUBSTITUTE-URLS}'
3879 Restart the daemon. For systemd, it goes like this:
3882 systemctl daemon-reload
3883 systemctl restart guix-daemon.service
3887 Authorize the key of the new server (@pxref{Invoking guix archive}):
3890 guix archive --authorize < key.pub
3893 Again this assumes @file{key.pub} contains the public key that
3894 @code{guix.example.org} uses to sign substitutes.
3897 Now you're all set! Substitutes will be preferably taken from
3898 @code{https://guix.example.org}, using
3899 @code{@value{SUBSTITUTE-SERVER-1}} then
3900 @code{@value{SUBSTITUTE-SERVER-2}} as fallback options. Of course you
3901 can list as many substitute servers as you like, with the caveat that
3902 substitute lookup can be slowed down if too many servers need to be
3905 Note that there are also situations where one may want to add the URL of
3906 a substitute server @emph{without} authorizing its key.
3907 @xref{Substitute Authentication}, to understand this fine point.
3909 @node Substitute Authentication
3910 @subsection Substitute Authentication
3912 @cindex digital signatures
3913 Guix detects and raises an error when attempting to use a substitute
3914 that has been tampered with. Likewise, it ignores substitutes that are
3915 not signed, or that are not signed by one of the keys listed in the ACL.
3917 There is one exception though: if an unauthorized server provides
3918 substitutes that are @emph{bit-for-bit identical} to those provided by
3919 an authorized server, then the unauthorized server becomes eligible for
3920 downloads. For example, assume we have chosen two substitute servers
3924 --substitute-urls="https://a.example.org https://b.example.org"
3928 @cindex reproducible builds
3929 If the ACL contains only the key for @samp{b.example.org}, and if
3930 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3931 then Guix will download substitutes from @samp{a.example.org} because it
3932 comes first in the list and can be considered a mirror of
3933 @samp{b.example.org}. In practice, independent build machines usually
3934 produce the same binaries, thanks to bit-reproducible builds (see
3937 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3938 (in other words, the server is not authenticated), contrary to what
3939 HTTPS clients such as Web browsers usually do. This is because Guix
3940 authenticates substitute information itself, as explained above, which
3941 is what we care about (whereas X.509 certificates are about
3942 authenticating bindings between domain names and public keys).
3944 @node Proxy Settings
3945 @subsection Proxy Settings
3949 Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
3950 @env{https_proxy} environment variables can be set in the environment of
3951 @command{guix-daemon} and are honored for downloads of substitutes.
3952 Note that the value of those environment variables in the environment
3953 where @command{guix build}, @command{guix package}, and other client
3954 commands are run has @emph{absolutely no effect}.
3956 @node Substitution Failure
3957 @subsection Substitution Failure
3959 Even when a substitute for a derivation is available, sometimes the
3960 substitution attempt will fail. This can happen for a variety of
3961 reasons: the substitute server might be offline, the substitute may
3962 recently have been deleted, the connection might have been interrupted,
3965 When substitutes are enabled and a substitute for a derivation is
3966 available, but the substitution attempt fails, Guix will attempt to
3967 build the derivation locally depending on whether or not
3968 @option{--fallback} was given (@pxref{fallback-option,, common build
3969 option @option{--fallback}}). Specifically, if @option{--fallback} was
3970 omitted, then no local build will be performed, and the derivation is
3971 considered to have failed. However, if @option{--fallback} was given,
3972 then Guix will attempt to build the derivation locally, and the success
3973 or failure of the derivation depends on the success or failure of the
3974 local build. Note that when substitutes are disabled or no substitute
3975 is available for the derivation in question, a local build will
3976 @emph{always} be performed, regardless of whether or not
3977 @option{--fallback} was given.
3979 To get an idea of how many substitutes are available right now, you can
3980 try running the @command{guix weather} command (@pxref{Invoking guix
3981 weather}). This command provides statistics on the substitutes provided
3984 @node On Trusting Binaries
3985 @subsection On Trusting Binaries
3987 @cindex trust, of pre-built binaries
3988 Today, each individual's control over their own computing is at the
3989 mercy of institutions, corporations, and groups with enough power and
3990 determination to subvert the computing infrastructure and exploit its
3991 weaknesses. While using substitutes can be convenient, we encourage
3992 users to also build on their own, or even run their own build farm, such
3993 that the project run substitute servers are less of an interesting
3994 target. One way to help is by publishing the software you build using
3995 @command{guix publish} so that others have one more choice of server to
3996 download substitutes from (@pxref{Invoking guix publish}).
3998 Guix has the foundations to maximize build reproducibility
3999 (@pxref{Features}). In most cases, independent builds of a given
4000 package or derivation should yield bit-identical results. Thus, through
4001 a diverse set of independent package builds, we can strengthen the
4002 integrity of our systems. The @command{guix challenge} command aims to
4003 help users assess substitute servers, and to assist developers in
4004 finding out about non-deterministic package builds (@pxref{Invoking guix
4005 challenge}). Similarly, the @option{--check} option of @command{guix
4006 build} allows users to check whether previously-installed substitutes
4007 are genuine by rebuilding them locally (@pxref{build-check,
4008 @command{guix build --check}}).
4010 In the future, we want Guix to have support to publish and retrieve
4011 binaries to/from other users, in a peer-to-peer fashion. If you would
4012 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
4014 @node Packages with Multiple Outputs
4015 @section Packages with Multiple Outputs
4017 @cindex multiple-output packages
4018 @cindex package outputs
4021 Often, packages defined in Guix have a single @dfn{output}---i.e., the
4022 source package leads to exactly one directory in the store. When running
4023 @command{guix install glibc}, one installs the default output of the
4024 GNU libc package; the default output is called @code{out}, but its name
4025 can be omitted as shown in this command. In this particular case, the
4026 default output of @code{glibc} contains all the C header files, shared
4027 libraries, static libraries, Info documentation, and other supporting
4030 Sometimes it is more appropriate to separate the various types of files
4031 produced from a single source package into separate outputs. For
4032 instance, the GLib C library (used by GTK+ and related packages)
4033 installs more than 20 MiB of reference documentation as HTML pages.
4034 To save space for users who do not need it, the documentation goes to a
4035 separate output, called @code{doc}. To install the main GLib output,
4036 which contains everything but the documentation, one would run:
4042 @cindex documentation
4043 The command to install its documentation is:
4046 guix install glib:doc
4049 Some packages install programs with different ``dependency footprints''.
4050 For instance, the WordNet package installs both command-line tools and
4051 graphical user interfaces (GUIs). The former depend solely on the C
4052 library, whereas the latter depend on Tcl/Tk and the underlying X
4053 libraries. In this case, we leave the command-line tools in the default
4054 output, whereas the GUIs are in a separate output. This allows users
4055 who do not need the GUIs to save space. The @command{guix size} command
4056 can help find out about such situations (@pxref{Invoking guix size}).
4057 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
4059 There are several such multiple-output packages in the GNU distribution.
4060 Other conventional output names include @code{lib} for libraries and
4061 possibly header files, @code{bin} for stand-alone programs, and
4062 @code{debug} for debugging information (@pxref{Installing Debugging
4063 Files}). The outputs of a packages are listed in the third column of
4064 the output of @command{guix package --list-available} (@pxref{Invoking
4068 @node Invoking guix gc
4069 @section Invoking @command{guix gc}
4071 @cindex garbage collector
4073 Packages that are installed, but not used, may be @dfn{garbage-collected}.
4074 The @command{guix gc} command allows users to explicitly run the garbage
4075 collector to reclaim space from the @file{/gnu/store} directory. It is
4076 the @emph{only} way to remove files from @file{/gnu/store}---removing
4077 files or directories manually may break it beyond repair!
4080 @cindex garbage collector roots
4081 The garbage collector has a set of known @dfn{roots}: any file under
4082 @file{/gnu/store} reachable from a root is considered @dfn{live} and
4083 cannot be deleted; any other file is considered @dfn{dead} and may be
4084 deleted. The set of garbage collector roots (``GC roots'' for short)
4085 includes default user profiles; by default, the symlinks under
4086 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
4087 added with @command{guix build --root}, for example (@pxref{Invoking
4088 guix build}). The @command{guix gc --list-roots} command lists them.
4090 Prior to running @code{guix gc --collect-garbage} to make space, it is
4091 often useful to remove old generations from user profiles; that way, old
4092 package builds referenced by those generations can be reclaimed. This
4093 is achieved by running @code{guix package --delete-generations}
4094 (@pxref{Invoking guix package}).
4096 Our recommendation is to run a garbage collection periodically, or when
4097 you are short on disk space. For instance, to guarantee that at least
4098 5@tie{}GB are available on your disk, simply run:
4104 It is perfectly safe to run as a non-interactive periodic job
4105 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4106 Running @command{guix gc} with no arguments will collect as
4107 much garbage as it can, but that is often inconvenient: you may find
4108 yourself having to rebuild or re-download software that is ``dead'' from
4109 the GC viewpoint but that is necessary to build other pieces of
4110 software---e.g., the compiler tool chain.
4112 The @command{guix gc} command has three modes of operation: it can be
4113 used to garbage-collect any dead files (the default), to delete specific
4114 files (the @option{--delete} option), to print garbage-collector
4115 information, or for more advanced queries. The garbage collection
4116 options are as follows:
4119 @item --collect-garbage[=@var{min}]
4120 @itemx -C [@var{min}]
4121 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4122 sub-directories. This is the default operation when no option is
4125 When @var{min} is given, stop once @var{min} bytes have been collected.
4126 @var{min} may be a number of bytes, or it may include a unit as a
4127 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4128 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4130 When @var{min} is omitted, collect all the garbage.
4132 @item --free-space=@var{free}
4133 @itemx -F @var{free}
4134 Collect garbage until @var{free} space is available under
4135 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4136 as @code{500MiB}, as described above.
4138 When @var{free} or more is already available in @file{/gnu/store}, do
4139 nothing and exit immediately.
4141 @item --delete-generations[=@var{duration}]
4142 @itemx -d [@var{duration}]
4143 Before starting the garbage collection process, delete all the generations
4144 older than @var{duration}, for all the user profiles; when run as root, this
4145 applies to all the profiles @emph{of all the users}.
4147 For example, this command deletes all the generations of all your profiles
4148 that are older than 2 months (except generations that are current), and then
4149 proceeds to free space until at least 10 GiB are available:
4152 guix gc -d 2m -F 10G
4157 Attempt to delete all the store files and directories specified as
4158 arguments. This fails if some of the files are not in the store, or if
4159 they are still live.
4161 @item --list-failures
4162 List store items corresponding to cached build failures.
4164 This prints nothing unless the daemon was started with
4165 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4166 @option{--cache-failures}}).
4169 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4173 List store items in use by currently running processes. These store
4174 items are effectively considered GC roots: they cannot be deleted.
4176 @item --clear-failures
4177 Remove the specified store items from the failed-build cache.
4179 Again, this option only makes sense when the daemon is started with
4180 @option{--cache-failures}. Otherwise, it does nothing.
4183 Show the list of dead files and directories still present in the
4184 store---i.e., files and directories no longer reachable from any root.
4187 Show the list of live store files and directories.
4191 In addition, the references among existing store files can be queried:
4197 @cindex package dependencies
4198 List the references (respectively, the referrers) of store files given
4204 List the requisites of the store files passed as arguments. Requisites
4205 include the store files themselves, their references, and the references
4206 of these, recursively. In other words, the returned list is the
4207 @dfn{transitive closure} of the store files.
4209 @xref{Invoking guix size}, for a tool to profile the size of the closure
4210 of an element. @xref{Invoking guix graph}, for a tool to visualize
4211 the graph of references.
4215 Return the derivation(s) leading to the given store items
4216 (@pxref{Derivations}).
4218 For example, this command:
4221 guix gc --derivers $(guix package -I ^emacs$ | cut -f4)
4225 returns the @file{.drv} file(s) leading to the @code{emacs} package
4226 installed in your profile.
4228 Note that there may be zero matching @file{.drv} files, for instance
4229 because these files have been garbage-collected. There can also be more
4230 than one matching @file{.drv} due to fixed-output derivations.
4233 Lastly, the following options allow you to check the integrity of the
4234 store and to control disk usage.
4238 @item --verify[=@var{options}]
4239 @cindex integrity, of the store
4240 @cindex integrity checking
4241 Verify the integrity of the store.
4243 By default, make sure that all the store items marked as valid in the
4244 database of the daemon actually exist in @file{/gnu/store}.
4246 When provided, @var{options} must be a comma-separated list containing one
4247 or more of @code{contents} and @code{repair}.
4249 When passing @option{--verify=contents}, the daemon computes the
4250 content hash of each store item and compares it against its hash in the
4251 database. Hash mismatches are reported as data corruptions. Because it
4252 traverses @emph{all the files in the store}, this command can take a
4253 long time, especially on systems with a slow disk drive.
4255 @cindex repairing the store
4256 @cindex corruption, recovering from
4257 Using @option{--verify=repair} or @option{--verify=contents,repair}
4258 causes the daemon to try to repair corrupt store items by fetching
4259 substitutes for them (@pxref{Substitutes}). Because repairing is not
4260 atomic, and thus potentially dangerous, it is available only to the
4261 system administrator. A lightweight alternative, when you know exactly
4262 which items in the store are corrupt, is @command{guix build --repair}
4263 (@pxref{Invoking guix build}).
4266 @cindex deduplication
4267 Optimize the store by hard-linking identical files---this is
4268 @dfn{deduplication}.
4270 The daemon performs deduplication after each successful build or archive
4271 import, unless it was started with @option{--disable-deduplication}
4272 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4273 this option is primarily useful when the daemon was running with
4274 @option{--disable-deduplication}.
4278 @node Invoking guix pull
4279 @section Invoking @command{guix pull}
4281 @cindex upgrading Guix
4282 @cindex updating Guix
4283 @cindex @command{guix pull}
4285 @cindex security, @command{guix pull}
4286 @cindex authenticity, of code obtained with @command{guix pull}
4287 Packages are installed or upgraded to the latest version available in
4288 the distribution currently available on your local machine. To update
4289 that distribution, along with the Guix tools, you must run @command{guix
4290 pull}: the command downloads the latest Guix source code and package
4291 descriptions, and deploys it. Source code is downloaded from a
4292 @uref{https://git-scm.com, Git} repository, by default the official
4293 GNU@tie{}Guix repository, though this can be customized. @command{guix
4294 pull} ensures that the code it downloads is @emph{authentic} by
4295 verifying that commits are signed by Guix developers.
4297 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4298 (@pxref{Channels}) specified by one of the followings, in this order:
4302 the @option{--channels} option;
4304 the user's @file{~/.config/guix/channels.scm} file;
4306 the system-wide @file{/etc/guix/channels.scm} file;
4308 the built-in default channels specified in the @code{%default-channels}
4312 On completion, @command{guix package} will use packages and package
4313 versions from this just-retrieved copy of Guix. Not only that, but all
4314 the Guix commands and Scheme modules will also be taken from that latest
4315 version. New @command{guix} sub-commands added by the update also
4318 Any user can update their Guix copy using @command{guix pull}, and the
4319 effect is limited to the user who ran @command{guix pull}. For
4320 instance, when user @code{root} runs @command{guix pull}, this has no
4321 effect on the version of Guix that user @code{alice} sees, and vice
4324 The result of running @command{guix pull} is a @dfn{profile} available
4325 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4326 make sure to add it to the beginning of your search path so that you use
4327 the latest version, and similarly for the Info manual
4328 (@pxref{Documentation}):
4331 export PATH="$HOME/.config/guix/current/bin:$PATH"
4332 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4335 The @option{--list-generations} or @option{-l} option lists past generations
4336 produced by @command{guix pull}, along with details about their provenance:
4340 Generation 1 Jun 10 2018 00:18:18
4342 repository URL: https://git.savannah.gnu.org/git/guix.git
4343 branch: origin/master
4344 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4346 Generation 2 Jun 11 2018 11:02:49
4348 repository URL: https://git.savannah.gnu.org/git/guix.git
4349 branch: origin/master
4350 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4351 2 new packages: keepalived, libnfnetlink
4352 6 packages upgraded: emacs-nix-mode@@2.0.4,
4353 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4354 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4356 Generation 3 Jun 13 2018 23:31:07 (current)
4358 repository URL: https://git.savannah.gnu.org/git/guix.git
4359 branch: origin/master
4360 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4361 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4362 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4365 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4366 describe the current status of Guix.
4368 This @code{~/.config/guix/current} profile works exactly like the profiles
4369 created by @command{guix package} (@pxref{Invoking guix package}). That
4370 is, you can list generations, roll back to the previous
4371 generation---i.e., the previous Guix---and so on:
4374 $ guix pull --roll-back
4375 switched from generation 3 to 2
4376 $ guix pull --delete-generations=1
4377 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4380 You can also use @command{guix package} (@pxref{Invoking guix package})
4381 to manage the profile by naming it explicitly:
4383 $ guix package -p ~/.config/guix/current --roll-back
4384 switched from generation 3 to 2
4385 $ guix package -p ~/.config/guix/current --delete-generations=1
4386 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4389 The @command{guix pull} command is usually invoked with no arguments,
4390 but it supports the following options:
4393 @item --url=@var{url}
4394 @itemx --commit=@var{commit}
4395 @itemx --branch=@var{branch}
4396 Download code for the @code{guix} channel from the specified @var{url}, at the
4397 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4398 string), or @var{branch}.
4400 @cindex @file{channels.scm}, configuration file
4401 @cindex configuration file for channels
4402 These options are provided for convenience, but you can also specify your
4403 configuration in the @file{~/.config/guix/channels.scm} file or using the
4404 @option{--channels} option (see below).
4406 @item --channels=@var{file}
4407 @itemx -C @var{file}
4408 Read the list of channels from @var{file} instead of
4409 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4410 @var{file} must contain Scheme code that
4411 evaluates to a list of channel objects. @xref{Channels}, for more
4414 @cindex channel news
4417 Display the list of packages added or upgraded since the previous
4418 generation, as well as, occasionally, news written by channel authors
4419 for their users (@pxref{Channels, Writing Channel News}).
4421 The package information is the same as displayed upon @command{guix
4422 pull} completion, but without ellipses; it is also similar to the output
4423 of @command{guix pull -l} for the last generation (see below).
4425 @item --list-generations[=@var{pattern}]
4426 @itemx -l [@var{pattern}]
4427 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4428 is provided, the subset of generations that match @var{pattern}.
4429 The syntax of @var{pattern} is the same as with @code{guix package
4430 --list-generations} (@pxref{Invoking guix package}).
4433 @cindex rolling back
4434 @cindex undoing transactions
4435 @cindex transactions, undoing
4436 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4437 undo the last transaction.
4439 @item --switch-generation=@var{pattern}
4440 @itemx -S @var{pattern}
4442 Switch to a particular generation defined by @var{pattern}.
4444 @var{pattern} may be either a generation number or a number prefixed
4445 with ``+'' or ``-''. The latter means: move forward/backward by a
4446 specified number of generations. For example, if you want to return to
4447 the latest generation after @option{--roll-back}, use
4448 @option{--switch-generation=+1}.
4450 @item --delete-generations[=@var{pattern}]
4451 @itemx -d [@var{pattern}]
4452 When @var{pattern} is omitted, delete all generations except the current
4455 This command accepts the same patterns as @option{--list-generations}.
4456 When @var{pattern} is specified, delete the matching generations. When
4457 @var{pattern} specifies a duration, generations @emph{older} than the
4458 specified duration match. For instance, @option{--delete-generations=1m}
4459 deletes generations that are more than one month old.
4461 If the current generation matches, it is @emph{not} deleted.
4463 Note that deleting generations prevents rolling back to them.
4464 Consequently, this command must be used with care.
4466 @xref{Invoking guix describe}, for a way to display information about the
4467 current generation only.
4469 @item --profile=@var{profile}
4470 @itemx -p @var{profile}
4471 Use @var{profile} instead of @file{~/.config/guix/current}.
4475 Show which channel commit(s) would be used and what would be built or
4476 substituted but do not actually do it.
4478 @item --allow-downgrades
4479 Allow pulling older or unrelated revisions of channels than those
4482 @cindex downgrade attacks, protection against
4483 By default, @command{guix pull} protects against so-called ``downgrade
4484 attacks'' whereby the Git repository of a channel would be reset to an
4485 earlier or unrelated revision of itself, potentially leading you to
4486 install older, known-vulnerable versions of software packages.
4489 Make sure you understand its security implications before using
4490 @option{--allow-downgrades}.
4493 @item --disable-authentication
4494 Allow pulling channel code without authenticating it.
4496 @cindex authentication, of channel code
4497 By default, @command{guix pull} authenticates code downloaded from
4498 channels by verifying that its commits are signed by authorized
4499 developers, and raises an error if this is not the case. This option
4500 instructs it to not perform any such verification.
4503 Make sure you understand its security implications before using
4504 @option{--disable-authentication}.
4507 @item --system=@var{system}
4508 @itemx -s @var{system}
4509 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4510 the system type of the build host.
4513 Use the bootstrap Guile to build the latest Guix. This option is only
4514 useful to Guix developers.
4517 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4518 repository and branch to pull from, as well as @emph{additional} repositories
4519 containing package modules that should be deployed. @xref{Channels}, for more
4522 In addition, @command{guix pull} supports all the common build options
4523 (@pxref{Common Build Options}).
4525 @node Invoking guix time-machine
4526 @section Invoking @command{guix time-machine}
4528 @cindex @command{guix time-machine}
4529 @cindex pinning, channels
4530 @cindex replicating Guix
4531 @cindex reproducibility, of Guix
4533 The @command{guix time-machine} command provides access to other
4534 revisions of Guix, for example to install older versions of packages,
4535 or to reproduce a computation in an identical environment. The revision
4536 of Guix to be used is defined by a commit or by a channel
4537 description file created by @command{guix describe}
4538 (@pxref{Invoking guix describe}).
4540 The general syntax is:
4543 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4546 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4547 @command{guix} command of the specified revision. The @var{options} that define
4548 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4551 @item --url=@var{url}
4552 @itemx --commit=@var{commit}
4553 @itemx --branch=@var{branch}
4554 Use the @code{guix} channel from the specified @var{url}, at the
4555 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4556 string), or @var{branch}.
4558 @item --channels=@var{file}
4559 @itemx -C @var{file}
4560 Read the list of channels from @var{file}. @var{file} must contain
4561 Scheme code that evaluates to a list of channel objects.
4562 @xref{Channels} for more information.
4565 As for @command{guix pull}, the absence of any options means that the
4566 latest commit on the master branch will be used. The command
4569 guix time-machine -- build hello
4572 will thus build the package @code{hello} as defined in the master branch,
4573 which is in general a newer revision of Guix than you have installed.
4574 Time travel works in both directions!
4576 Note that @command{guix time-machine} can trigger builds of channels and
4577 their dependencies, and these are controlled by the standard build
4578 options (@pxref{Common Build Options}).
4583 @c TODO: Remove this once we're more confident about API stability.
4585 The functionality described here is a ``technology preview'' as of version
4586 @value{VERSION}. As such, the interface is subject to change.
4590 @cindex composition of Guix revisions
4591 Sometimes you might need to mix packages from the revision of Guix you're
4592 currently running with packages available in a different revision of Guix.
4593 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4594 revisions in arbitrary ways.
4596 @cindex inferior packages
4597 Technically, an ``inferior'' is essentially a separate Guix process connected
4598 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4599 @code{(guix inferior)} module allows you to create inferiors and to
4600 communicate with them. It also provides a high-level interface to browse and
4601 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4603 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4604 to interact with a separate revision of Guix. For example, let's assume you
4605 want to install in your profile the current @code{guile} package, along with
4606 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4607 because the newer @code{guile-json} has an incompatible API and you want to
4608 run your code against the old API@. To do that, you could write a manifest for
4609 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4610 manifest, you would create an inferior for that old Guix revision you care
4611 about, and you would look up the @code{guile-json} package in the inferior:
4614 (use-modules (guix inferior) (guix channels)
4615 (srfi srfi-1)) ;for 'first'
4618 ;; This is the old revision from which we want to
4619 ;; extract guile-json.
4622 (url "https://git.savannah.gnu.org/git/guix.git")
4624 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4627 ;; An inferior representing the above revision.
4628 (inferior-for-channels channels))
4630 ;; Now create a manifest with the current "guile" package
4631 ;; and the old "guile-json" package.
4633 (list (first (lookup-inferior-packages inferior "guile-json"))
4634 (specification->package "guile")))
4637 On its first run, @command{guix package --manifest} might have to build the
4638 channel you specified before it can create the inferior; subsequent runs will
4639 be much faster because the Guix revision will be cached.
4641 The @code{(guix inferior)} module provides the following procedures to open an
4644 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4645 [#:cache-directory] [#:ttl]
4646 Return an inferior for @var{channels}, a list of channels. Use the cache at
4647 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4648 This procedure opens a new connection to the build daemon.
4650 As a side effect, this procedure may build or substitute binaries for
4651 @var{channels}, which can take time.
4654 @deffn {Scheme Procedure} open-inferior @var{directory} @
4655 [#:command "bin/guix"]
4656 Open the inferior Guix in @var{directory}, running
4657 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4658 the inferior could not be launched.
4661 @cindex inferior packages
4662 The procedures listed below allow you to obtain and manipulate inferior
4665 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4666 Return the list of packages known to @var{inferior}.
4669 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4671 Return the sorted list of inferior packages matching @var{name} in
4672 @var{inferior}, with highest version numbers first. If @var{version} is true,
4673 return only packages with a version number prefixed by @var{version}.
4676 @deffn {Scheme Procedure} inferior-package? @var{obj}
4677 Return true if @var{obj} is an inferior package.
4680 @deffn {Scheme Procedure} inferior-package-name @var{package}
4681 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4682 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4683 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4684 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4685 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4686 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4687 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4688 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4689 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4690 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4691 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4692 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4693 These procedures are the counterpart of package record accessors
4694 (@pxref{package Reference}). Most of them work by querying the inferior
4695 @var{package} comes from, so the inferior must still be live when you call
4699 Inferior packages can be used transparently like any other package or
4700 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4701 transparently handled by the @code{packages->manifest} procedure, which is
4702 commonly used in manifests (@pxref{Invoking guix package, the
4703 @option{--manifest} option of @command{guix package}}). Thus you can insert
4704 an inferior package pretty much anywhere you would insert a regular package:
4705 in manifests, in the @code{packages} field of your @code{operating-system}
4706 declaration, and so on.
4708 @node Invoking guix describe
4709 @section Invoking @command{guix describe}
4711 @cindex reproducibility
4712 @cindex replicating Guix
4713 Often you may want to answer questions like: ``Which revision of Guix am I
4714 using?'' or ``Which channels am I using?'' This is useful information in many
4715 situations: if you want to @emph{replicate} an environment on a different
4716 machine or user account, if you want to report a bug or to determine what
4717 change in the channels you are using caused it, or if you want to record your
4718 system state for reproducibility purposes. The @command{guix describe}
4719 command answers these questions.
4721 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4722 displays the channel(s) that it was built from, including their repository URL
4723 and commit IDs (@pxref{Channels}):
4727 Generation 10 Sep 03 2018 17:32:44 (current)
4729 repository URL: https://git.savannah.gnu.org/git/guix.git
4731 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4734 If you're familiar with the Git version control system, this is similar in
4735 spirit to @command{git describe}; the output is also similar to that of
4736 @command{guix pull --list-generations}, but limited to the current generation
4737 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4738 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4739 information is all it takes to describe the revision of Guix you're using, and
4740 also to replicate it.
4742 To make it easier to replicate Guix, @command{guix describe} can also be asked
4743 to return a list of channels instead of the human-readable description above:
4746 $ guix describe -f channels
4749 (url "https://git.savannah.gnu.org/git/guix.git")
4751 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4753 (make-channel-introduction
4754 "9edb3f66fd807b096b48283debdcddccfea34bad"
4755 (openpgp-fingerprint
4756 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4760 You can save this to a file and feed it to @command{guix pull -C} on some
4761 other machine or at a later point in time, which will instantiate @emph{this
4762 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4763 From there on, since you're able to deploy the same revision of Guix, you can
4764 just as well @emph{replicate a complete software environment}. We humbly
4765 think that this is @emph{awesome}, and we hope you'll like it too!
4767 The details of the options supported by @command{guix describe} are as
4771 @item --format=@var{format}
4772 @itemx -f @var{format}
4773 Produce output in the specified @var{format}, one of:
4777 produce human-readable output;
4779 produce a list of channel specifications that can be passed to @command{guix
4780 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4782 @item channels-sans-intro
4783 like @code{channels}, but omit the @code{introduction} field; use it to
4784 produce a channel specification suitable for Guix version 1.1.0 or
4785 earlier---the @code{introduction} field has to do with channel
4786 authentication (@pxref{Channels, Channel Authentication}) and is not
4787 supported by these older versions;
4790 produce a list of channel specifications in JSON format;
4792 produce a list of channel specifications in Recutils format.
4795 @item --list-formats
4796 Display available formats for @option{--format} option.
4798 @item --profile=@var{profile}
4799 @itemx -p @var{profile}
4800 Display information about @var{profile}.
4803 @node Invoking guix archive
4804 @section Invoking @command{guix archive}
4806 @cindex @command{guix archive}
4808 The @command{guix archive} command allows users to @dfn{export} files
4809 from the store into a single archive, and to later @dfn{import} them on
4810 a machine that runs Guix.
4811 In particular, it allows store files to be transferred from one machine
4812 to the store on another machine.
4815 If you're looking for a way to produce archives in a format suitable for
4816 tools other than Guix, @pxref{Invoking guix pack}.
4819 @cindex exporting store items
4820 To export store files as an archive to standard output, run:
4823 guix archive --export @var{options} @var{specifications}...
4826 @var{specifications} may be either store file names or package
4827 specifications, as for @command{guix package} (@pxref{Invoking guix
4828 package}). For instance, the following command creates an archive
4829 containing the @code{gui} output of the @code{git} package and the main
4830 output of @code{emacs}:
4833 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4836 If the specified packages are not built yet, @command{guix archive}
4837 automatically builds them. The build process may be controlled with the
4838 common build options (@pxref{Common Build Options}).
4840 To transfer the @code{emacs} package to a machine connected over SSH,
4844 guix archive --export -r emacs | ssh the-machine guix archive --import
4848 Similarly, a complete user profile may be transferred from one machine
4849 to another like this:
4852 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4853 ssh the-machine guix archive --import
4857 However, note that, in both examples, all of @code{emacs} and the
4858 profile as well as all of their dependencies are transferred (due to
4859 @option{-r}), regardless of what is already available in the store on
4860 the target machine. The @option{--missing} option can help figure out
4861 which items are missing from the target store. The @command{guix copy}
4862 command simplifies and optimizes this whole process, so this is probably
4863 what you should use in this case (@pxref{Invoking guix copy}).
4865 @cindex nar, archive format
4866 @cindex normalized archive (nar)
4867 @cindex nar bundle, archive format
4868 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4869 format (described below), and the output of @command{guix archive
4870 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4874 comparable in spirit to `tar', but with differences
4875 that make it more appropriate for our purposes. First, rather than
4876 recording all Unix metadata for each file, the nar format only mentions
4877 the file type (regular, directory, or symbolic link); Unix permissions
4878 and owner/group are dismissed. Second, the order in which directory
4879 entries are stored always follows the order of file names according to
4880 the C locale collation order. This makes archive production fully
4883 That nar bundle format is essentially the concatenation of zero or more
4884 nars along with metadata for each store item it contains: its file name,
4885 references, corresponding derivation, and a digital signature.
4887 When exporting, the daemon digitally signs the contents of the archive,
4888 and that digital signature is appended. When importing, the daemon
4889 verifies the signature and rejects the import in case of an invalid
4890 signature or if the signing key is not authorized.
4891 @c FIXME: Add xref to daemon doc about signatures.
4893 The main options are:
4897 Export the specified store files or packages (see below). Write the
4898 resulting archive to the standard output.
4900 Dependencies are @emph{not} included in the output, unless
4901 @option{--recursive} is passed.
4905 When combined with @option{--export}, this instructs @command{guix archive}
4906 to include dependencies of the given items in the archive. Thus, the
4907 resulting archive is self-contained: it contains the closure of the
4908 exported store items.
4911 Read an archive from the standard input, and import the files listed
4912 therein into the store. Abort if the archive has an invalid digital
4913 signature, or if it is signed by a public key not among the authorized
4914 keys (see @option{--authorize} below).
4917 Read a list of store file names from the standard input, one per line,
4918 and write on the standard output the subset of these files missing from
4921 @item --generate-key[=@var{parameters}]
4922 @cindex signing, archives
4923 Generate a new key pair for the daemon. This is a prerequisite before
4924 archives can be exported with @option{--export}. This
4925 operation is usually instantaneous but it can take time if the system's
4926 entropy pool needs to be refilled. On Guix System,
4927 @code{guix-service-type} takes care of generating this key pair the
4930 The generated key pair is typically stored under @file{/etc/guix}, in
4931 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4932 key, which must be kept secret). When @var{parameters} is omitted,
4933 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4934 versions before 1.6.0, it is a 4096-bit RSA key.
4935 Alternatively, @var{parameters} can specify
4936 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4937 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4938 Libgcrypt Reference Manual}).
4941 @cindex authorizing, archives
4942 Authorize imports signed by the public key passed on standard input.
4943 The public key must be in ``s-expression advanced format''---i.e., the
4944 same format as the @file{signing-key.pub} file.
4946 The list of authorized keys is kept in the human-editable file
4947 @file{/etc/guix/acl}. The file contains
4948 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4949 s-expressions''} and is structured as an access-control list in the
4950 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4953 @item --extract=@var{directory}
4954 @itemx -x @var{directory}
4955 Read a single-item archive as served by substitute servers
4956 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4957 low-level operation needed in only very narrow use cases; see below.
4959 For example, the following command extracts the substitute for Emacs
4960 served by @code{@value{SUBSTITUTE-SERVER-1}} to @file{/tmp/emacs}:
4964 https://@value{SUBSTITUTE-SERVER-1}/nar/gzip/@dots{}-emacs-24.5 \
4965 | gunzip | guix archive -x /tmp/emacs
4968 Single-item archives are different from multiple-item archives produced
4969 by @command{guix archive --export}; they contain a single store item,
4970 and they do @emph{not} embed a signature. Thus this operation does
4971 @emph{no} signature verification and its output should be considered
4974 The primary purpose of this operation is to facilitate inspection of
4975 archive contents coming from possibly untrusted substitute servers
4976 (@pxref{Invoking guix challenge}).
4980 Read a single-item archive as served by substitute servers
4981 (@pxref{Substitutes}) and print the list of files it contains, as in
4986 https://@value{SUBSTITUTE-SERVER-1}/nar/lzip/@dots{}-emacs-26.3 \
4987 | lzip -d | guix archive -t
4992 @c *********************************************************************
4997 @cindex @file{channels.scm}, configuration file
4998 @cindex configuration file for channels
4999 @cindex @command{guix pull}, configuration file
5000 @cindex configuration of @command{guix pull}
5001 Guix and its package collection are updated by running @command{guix pull}
5002 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
5003 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
5004 customized by defining @dfn{channels} in the
5005 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
5006 of a Git repository to be deployed, and @command{guix pull} can be instructed
5007 to pull from one or more channels. In other words, channels can be used
5008 to @emph{customize} and to @emph{extend} Guix, as we will see below.
5009 Guix is able to take into account security concerns and deal with authenticated
5013 * Specifying Additional Channels:: Extending the package collection.
5014 * Using a Custom Guix Channel:: Using a customized Guix.
5015 * Replicating Guix:: Running the @emph{exact same} Guix.
5016 * Channel Authentication:: How Guix verifies what it fetches.
5017 * Channels with Substitutes:: Using channels with available substitutes.
5018 * Creating a Channel:: How to write your custom channel.
5019 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
5020 * Declaring Channel Dependencies:: How to depend on other channels.
5021 * Specifying Channel Authorizations:: Defining channel authors authorizations.
5022 * Primary URL:: Distinguishing mirror to original.
5023 * Writing Channel News:: Communicating information to channel's users.
5026 @node Specifying Additional Channels
5027 @section Specifying Additional Channels
5029 @cindex extending the package collection (channels)
5030 @cindex variant packages (channels)
5031 You can specify @emph{additional channels} to pull from. To use a channel, write
5032 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
5033 @emph{in addition} to the default Guix channel(s):
5035 @vindex %default-channels
5037 ;; Add variant packages to those Guix provides.
5039 (name 'variant-packages)
5040 (url "https://example.org/variant-packages.git"))
5045 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
5046 add a channel the list of channels that the variable @code{%default-channels}
5047 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
5048 Manual}). With this file in place, @command{guix pull} builds not only Guix
5049 but also the package modules from your own repository. The result in
5050 @file{~/.config/guix/current} is the union of Guix with your own package
5054 $ guix pull --list-generations
5056 Generation 19 Aug 27 2018 16:20:48
5058 repository URL: https://git.savannah.gnu.org/git/guix.git
5060 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
5061 variant-packages dd3df5e
5062 repository URL: https://example.org/variant-packages.git
5064 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
5065 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
5066 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
5070 The output of @command{guix pull} above shows that Generation@tie{}19 includes
5071 both Guix and packages from the @code{variant-personal-packages} channel. Among
5072 the new and upgraded packages that are listed, some like @code{variant-gimp} and
5073 @code{variant-emacs-with-cool-features} might come from
5074 @code{variant-packages}, while others come from the Guix default channel.
5076 @node Using a Custom Guix Channel
5077 @section Using a Custom Guix Channel
5079 The channel called @code{guix} specifies where Guix itself---its command-line
5080 tools as well as its package collection---should be downloaded. For instance,
5081 suppose you want to update from another copy of the Guix repository at
5082 @code{example.org}, and specifically the @code{super-hacks} branch, you can
5083 write in @code{~/.config/guix/channels.scm} this specification:
5086 ;; Tell 'guix pull' to use another repo.
5089 (url "https://example.org/another-guix.git")
5090 (branch "super-hacks")))
5094 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
5095 branch of the repository at @code{example.org}. The authentication concern is
5096 addressed below ((@pxref{Channel Authentication}).
5098 @node Replicating Guix
5099 @section Replicating Guix
5101 @cindex pinning, channels
5102 @cindex replicating Guix
5103 @cindex reproducibility, of Guix
5104 The @command{guix pull --list-generations} output above shows precisely which
5105 commits were used to build this instance of Guix. We can thus replicate it,
5106 say, on another machine, by providing a channel specification in
5107 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
5110 ;; Deploy specific commits of my channels of interest.
5113 (url "https://git.savannah.gnu.org/git/guix.git")
5114 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5116 (name 'variant-packages)
5117 (url "https://example.org/variant-packages.git")
5118 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5121 The @command{guix describe --format=channels} command can even generate this
5122 list of channels directly (@pxref{Invoking guix describe}). The resulting
5123 file can be used with the -C options of @command{guix pull}
5124 (@pxref{Invoking guix pull}) or @command{guix time-machine}
5125 (@pxref{Invoking guix time-machine}).
5127 At this point the two machines run the @emph{exact same Guix}, with access to
5128 the @emph{exact same packages}. The output of @command{guix build gimp} on
5129 one machine will be exactly the same, bit for bit, as the output of the same
5130 command on the other machine. It also means both machines have access to all
5131 the source code of Guix and, transitively, to all the source code of every
5134 This gives you super powers, allowing you to track the provenance of binary
5135 artifacts with very fine grain, and to reproduce software environments at
5136 will---some sort of ``meta reproducibility'' capabilities, if you will.
5137 @xref{Inferiors}, for another way to take advantage of these super powers.
5139 @node Channel Authentication
5140 @section Channel Authentication
5142 @anchor{channel-authentication}
5143 @cindex authentication, of channel code
5144 The @command{guix pull} and @command{guix time-machine} commands
5145 @dfn{authenticate} the code retrieved from channels: they make sure each
5146 commit that is fetched is signed by an authorized developer. The goal
5147 is to protect from unauthorized modifications to the channel that would
5148 lead users to run malicious code.
5150 As a user, you must provide a @dfn{channel introduction} in your
5151 channels file so that Guix knows how to authenticate its first commit.
5152 A channel specification, including its introduction, looks something
5157 (name 'some-channel)
5158 (url "https://example.org/some-channel.git")
5160 (make-channel-introduction
5161 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5162 (openpgp-fingerprint
5163 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5166 The specification above shows the name and URL of the channel. The call
5167 to @code{make-channel-introduction} above specifies that authentication
5168 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5169 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5171 For the main channel, called @code{guix}, you automatically get that
5172 information from your Guix installation. For other channels, include
5173 the channel introduction provided by the channel authors in your
5174 @file{channels.scm} file. Make sure you retrieve the channel
5175 introduction from a trusted source since that is the root of your trust.
5177 If you're curious about the authentication mechanics, read on!
5179 @node Channels with Substitutes
5180 @section Channels with Substitutes
5182 When running @command{guix pull}, Guix will first compile the
5183 definitions of every available package. This is an expensive operation
5184 for which substitutes (@pxref{Substitutes}) may be available. The
5185 following snippet in @file{channels.scm} will ensure that @command{guix
5186 pull} uses the latest commit with available substitutes for the package
5187 definitions: this is done by querying the continuous integration
5188 server at @url{https://ci.guix.gnu.org}.
5191 (use-modules (guix ci))
5193 (list (channel-with-substitutes-available
5194 %default-guix-channel
5195 "https://ci.guix.gnu.org"))
5198 Note that this does not mean that all the packages that you will
5199 install after running @command{guix pull} will have available
5200 substitutes. It only ensures that @command{guix pull} will not try to
5201 compile package definitions. This is particularly useful when using
5202 machines with limited resources.
5204 @node Creating a Channel
5205 @section Creating a Channel
5207 @cindex personal packages (channels)
5208 @cindex channels, for personal packages
5209 Let's say you have a bunch of custom package variants or personal packages
5210 that you think would make little sense to contribute to the Guix project, but
5211 would like to have these packages transparently available to you at the
5212 command line. You would first write modules containing those package
5213 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5214 then you and anyone else can use it as an additional channel to get packages
5217 @c What follows stems from discussions at
5218 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5219 @c earlier discussions on guix-devel@gnu.org.
5221 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5222 publish your personal channel to the world, we would like to share a few words
5227 Before publishing a channel, please consider contributing your package
5228 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5229 to free software of all sorts, and packages in Guix proper are readily
5230 available to all Guix users and benefit from the project's quality assurance
5234 When you maintain package definitions outside Guix, we, Guix developers,
5235 consider that @emph{the compatibility burden is on you}. Remember that
5236 package modules and package definitions are just Scheme code that uses various
5237 programming interfaces (APIs). We want to remain free to change these APIs to
5238 keep improving Guix, possibly in ways that break your channel. We never
5239 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5243 Corollary: if you're using an external channel and that channel breaks, please
5244 @emph{report the issue to the channel authors}, not to the Guix project.
5247 You've been warned! Having said this, we believe external channels are a
5248 practical way to exert your freedom to augment Guix' package collection and to
5249 share your improvements, which are basic tenets of
5250 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5251 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5254 To create a channel, create a Git repository containing your own package
5255 modules and make it available. The repository can contain anything, but a
5256 useful channel will contain Guile modules that export packages. Once you
5257 start using a channel, Guix will behave as if the root directory of that
5258 channel's Git repository has been added to the Guile load path (@pxref{Load
5259 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5260 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5261 module, then the module will be available under the name @code{(my-packages
5262 my-tools)}, and you will be able to use it like any other module
5263 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5265 As a channel author, consider bundling authentication material with your
5266 channel so that users can authenticate it. @xref{Channel
5267 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5271 @node Package Modules in a Sub-directory
5272 @section Package Modules in a Sub-directory
5274 @cindex subdirectory, channels
5275 As a channel author, you may want to keep your channel modules in a
5276 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5277 add a meta-data file @file{.guix-channel} that contains:
5285 @node Declaring Channel Dependencies
5286 @section Declaring Channel Dependencies
5288 @cindex dependencies, channels
5289 @cindex meta-data, channels
5290 Channel authors may decide to augment a package collection provided by other
5291 channels. They can declare their channel to be dependent on other channels in
5292 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5293 the channel repository.
5295 The meta-data file should contain a simple S-expression like this:
5302 (name some-collection)
5303 (url "https://example.org/first-collection.git")
5305 ;; The 'introduction' bit below is optional: you would
5306 ;; provide it for dependencies that can be authenticated.
5308 (channel-introduction
5310 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5311 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5313 (name some-other-collection)
5314 (url "https://example.org/second-collection.git")
5315 (branch "testing"))))
5318 In the above example this channel is declared to depend on two other channels,
5319 which will both be fetched automatically. The modules provided by the channel
5320 will be compiled in an environment where the modules of all these declared
5321 channels are available.
5323 For the sake of reliability and maintainability, you should avoid dependencies
5324 on channels that you don't control, and you should aim to keep the number of
5325 dependencies to a minimum.
5327 @node Specifying Channel Authorizations
5328 @section Specifying Channel Authorizations
5330 @cindex channel authorizations
5331 @anchor{channel-authorizations}
5332 As we saw above, Guix ensures the source code it pulls from channels
5333 comes from authorized developers. As a channel author, you need to
5334 specify the list of authorized developers in the
5335 @file{.guix-authorizations} file in the channel's Git repository. The
5336 authentication rule is simple: each commit must be signed by a key
5337 listed in the @file{.guix-authorizations} file of its parent
5338 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5339 (DAG). Each commit can have zero or more parents; ``regular'' commits
5340 have one parent and merge commits have two parent commits. Read
5341 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5342 for Computer Scientists}} for a great overview.} The
5343 @file{.guix-authorizations} file looks like this:
5346 ;; Example '.guix-authorizations' file.
5349 (version 0) ;current file format version
5351 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5353 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5355 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5359 Each fingerprint is followed by optional key/value pairs, as in the
5360 example above. Currently these key/value pairs are ignored.
5362 This authentication rule creates a chicken-and-egg issue: how do we
5363 authenticate the first commit? Related to that: how do we deal with
5364 channels whose repository history contains unsigned commits and lack
5365 @file{.guix-authorizations}? And how do we fork existing channels?
5367 @cindex channel introduction
5368 Channel introductions answer these questions by describing the first
5369 commit of a channel that should be authenticated. The first time a
5370 channel is fetched with @command{guix pull} or @command{guix
5371 time-machine}, the command looks up the introductory commit and verifies
5372 that it is signed by the specified OpenPGP key. From then on, it
5373 authenticates commits according to the rule above.
5375 Additionally, your channel must provide all the OpenPGP keys that were
5376 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5377 files, which can be either binary or ``ASCII-armored''. By default,
5378 those @file{.key} files are searched for in the branch named
5379 @code{keyring} but you can specify a different branch name in
5380 @code{.guix-channel} like so:
5385 (keyring-reference "my-keyring-branch"))
5388 To summarize, as the author of a channel, there are three things you have
5389 to do to allow users to authenticate your code:
5393 Export the OpenPGP keys of past and present committers with @command{gpg
5394 --export} and store them in @file{.key} files, by default in a branch
5395 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5398 Introduce an initial @file{.guix-authorizations} in the channel's
5399 repository. Do that in a signed commit (@pxref{Commit Access}, for
5400 information on how to sign Git commits.)
5403 Advertise the channel introduction, for instance on your channel's web
5404 page. The channel introduction, as we saw above, is the commit/key
5405 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5406 the fingerprint of the OpenPGP used to sign it.
5409 Before pushing to your public Git repository, you can run @command{guix
5410 git-authenticate} to verify that you did sign all the commits you are
5411 about to push with an authorized key:
5414 guix git authenticate @var{commit} @var{signer}
5418 where @var{commit} and @var{signer} are your channel introduction.
5419 @xref{Invoking guix git authenticate}, for details.
5421 Publishing a signed channel requires discipline: any mistake, such as an
5422 unsigned commit or a commit signed by an unauthorized key, will prevent
5423 users from pulling from your channel---well, that's the whole point of
5424 authentication! Pay attention to merges in particular: merge commits
5425 are considered authentic if and only if they are signed by a key present
5426 in the @file{.guix-authorizations} file of @emph{both} branches.
5429 @section Primary URL
5431 @cindex primary URL, channels
5432 Channel authors can indicate the primary URL of their channel's Git
5433 repository in the @file{.guix-channel} file, like so:
5438 (url "https://example.org/guix.git"))
5441 This allows @command{guix pull} to determine whether it is pulling code
5442 from a mirror of the channel; when that is the case, it warns the user
5443 that the mirror might be stale and displays the primary URL@. That way,
5444 users cannot be tricked into fetching code from a stale mirror that does
5445 not receive security updates.
5447 This feature only makes sense for authenticated repositories, such as
5448 the official @code{guix} channel, for which @command{guix pull} ensures
5449 the code it fetches is authentic.
5451 @node Writing Channel News
5452 @section Writing Channel News
5454 @cindex news, for channels
5455 Channel authors may occasionally want to communicate to their users
5456 information about important changes in the channel. You'd send them all
5457 an email, but that's not convenient.
5459 Instead, channels can provide a @dfn{news file}; when the channel users
5460 run @command{guix pull}, that news file is automatically read and
5461 @command{guix pull --news} can display the announcements that correspond
5462 to the new commits that have been pulled, if any.
5464 To do that, channel authors must first declare the name of the news file
5465 in their @file{.guix-channel} file:
5470 (news-file "etc/news.txt"))
5473 The news file itself, @file{etc/news.txt} in this example, must look
5474 something like this:
5479 (entry (tag "the-bug-fix")
5480 (title (en "Fixed terrible bug")
5482 (body (en "@@emph@{Good news@}! It's fixed!")
5483 (eo "Certe ĝi pli bone funkcias nun!")))
5484 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5485 (title (en "Added a great package")
5486 (ca "Què vol dir guix?"))
5487 (body (en "Don't miss the @@code@{hello@} package!"))))
5490 While the news file is using the Scheme syntax, avoid naming it with a
5491 @file{.scm} extension or else it will get picked up when building the
5492 channel and yield an error since it is not a valid module.
5493 Alternatively, you can move the channel module to a subdirectory and
5494 store the news file in another directory.
5496 The file consists of a list of @dfn{news entries}. Each entry is
5497 associated with a commit or tag: it describes changes made in this
5498 commit, possibly in preceding commits as well. Users see entries only
5499 the first time they obtain the commit the entry refers to.
5501 The @code{title} field should be a one-line summary while @code{body}
5502 can be arbitrarily long, and both can contain Texinfo markup
5503 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5504 a list of language tag/message tuples, which allows @command{guix pull}
5505 to display news in the language that corresponds to the user's locale.
5507 If you want to translate news using a gettext-based workflow, you can
5508 extract translatable strings with @command{xgettext} (@pxref{xgettext
5509 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5510 you write news entries in English first, the command below creates a PO
5511 file containing the strings to translate:
5514 xgettext -o news.po -l scheme -ken etc/news.txt
5517 To sum up, yes, you could use your channel as a blog. But beware, this
5518 is @emph{not quite} what your users might expect.
5520 @c *********************************************************************
5522 @chapter Development
5524 @cindex software development
5525 If you are a software developer, Guix provides tools that you should find
5526 helpful---independently of the language you're developing in. This is what
5527 this chapter is about.
5529 The @command{guix environment} command provides a convenient way to set up
5530 @dfn{development environments} containing all the dependencies and tools
5531 necessary to work on the software package of your choice. The @command{guix
5532 pack} command allows you to create @dfn{application bundles} that can be
5533 easily distributed to users who do not run Guix.
5536 * Invoking guix environment:: Setting up development environments.
5537 * Invoking guix pack:: Creating software bundles.
5538 * The GCC toolchain:: Working with languages supported by GCC.
5539 * Invoking guix git authenticate:: Authenticating Git repositories.
5542 @node Invoking guix environment
5543 @section Invoking @command{guix environment}
5545 @cindex reproducible build environments
5546 @cindex development environments
5547 @cindex @command{guix environment}
5548 @cindex environment, package build environment
5549 The purpose of @command{guix environment} is to assist hackers in
5550 creating reproducible development environments without polluting their
5551 package profile. The @command{guix environment} tool takes one or more
5552 packages, builds all of their inputs, and creates a shell
5553 environment to use them.
5555 The general syntax is:
5558 guix environment @var{options} @var{package}@dots{}
5561 The following example spawns a new shell set up for the development of
5565 guix environment guile
5568 If the needed dependencies are not built yet, @command{guix environment}
5569 automatically builds them. The environment of the new shell is an
5570 augmented version of the environment that @command{guix environment} was
5571 run in. It contains the necessary search paths for building the given
5572 package added to the existing environment variables. To create
5573 a ``pure'' environment, in which the original environment variables have
5574 been unset, use the @option{--pure} option@footnote{Users sometimes
5575 wrongfully augment environment variables such as @env{PATH} in their
5576 @file{~/.bashrc} file. As a consequence, when @command{guix
5577 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5578 introducing ``impurities'' in these environment variables. It is an
5579 error to define such environment variables in @file{.bashrc}; instead,
5580 they should be defined in @file{.bash_profile}, which is sourced only by
5581 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5582 Manual}, for details on Bash start-up files.}.
5584 Exiting from a Guix environment is the same as exiting from the shell,
5585 and will place the user back in the old environment before @command{guix
5586 environment} was invoked. The next garbage collection (@pxref{Invoking
5587 guix gc}) will clean up packages that were installed from within the
5588 environment and are no longer used outside of it.
5590 @vindex GUIX_ENVIRONMENT
5591 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5592 variable in the shell it spawns; its value is the file name of the
5593 profile of this environment. This allows users to, say, define a
5594 specific prompt for development environments in their @file{.bashrc}
5595 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5598 if [ -n "$GUIX_ENVIRONMENT" ]
5600 export PS1="\u@@\h \w [dev]\$ "
5605 ...@: or to browse the profile:
5608 $ ls "$GUIX_ENVIRONMENT/bin"
5611 Additionally, more than one package may be specified, in which case the
5612 union of the inputs for the given packages are used. For example, the
5613 command below spawns a shell where all of the dependencies of both Guile
5614 and Emacs are available:
5617 guix environment guile emacs
5620 Sometimes an interactive shell session is not desired. An arbitrary
5621 command may be invoked by placing the @code{--} token to separate the
5622 command from the rest of the arguments:
5625 guix environment guile -- make -j4
5628 In other situations, it is more convenient to specify the list of
5629 packages needed in the environment. For example, the following command
5630 runs @command{python} from an environment containing Python@tie{}2.7 and
5634 guix environment --ad-hoc python2-numpy python-2.7 -- python
5637 Furthermore, one might want the dependencies of a package and also some
5638 additional packages that are not build-time or runtime dependencies, but
5639 are useful when developing nonetheless. Because of this, the
5640 @option{--ad-hoc} flag is positional. Packages appearing before
5641 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5642 added to the environment. Packages appearing after are interpreted as
5643 packages that will be added to the environment directly. For example,
5644 the following command creates a Guix development environment that
5645 additionally includes Git and strace:
5648 guix environment --pure guix --ad-hoc git strace
5652 Sometimes it is desirable to isolate the environment as much as
5653 possible, for maximal purity and reproducibility. In particular, when
5654 using Guix on a host distro that is not Guix System, it is desirable to
5655 prevent access to @file{/usr/bin} and other system-wide resources from
5656 the development environment. For example, the following command spawns
5657 a Guile REPL in a ``container'' where only the store and the current
5658 working directory are mounted:
5661 guix environment --ad-hoc --container guile -- guile
5665 The @option{--container} option requires Linux-libre 3.19 or newer.
5668 @cindex certificates
5669 Another typical use case for containers is to run security-sensitive
5670 applications such as a web browser. To run Eolie, we must expose and
5671 share some files and directories; we include @code{nss-certs} and expose
5672 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5673 @env{DISPLAY} environment variable since containerized graphical
5674 applications won't display without it.
5677 guix environment --preserve='^DISPLAY$' --container --network \
5678 --expose=/etc/machine-id \
5679 --expose=/etc/ssl/certs/ \
5680 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5681 --ad-hoc eolie nss-certs dbus -- eolie
5684 The available options are summarized below.
5687 @item --root=@var{file}
5688 @itemx -r @var{file}
5689 @cindex persistent environment
5690 @cindex garbage collector root, for environments
5691 Make @var{file} a symlink to the profile for this environment, and
5692 register it as a garbage collector root.
5694 This is useful if you want to protect your environment from garbage
5695 collection, to make it ``persistent''.
5697 When this option is omitted, the environment is protected from garbage
5698 collection only for the duration of the @command{guix environment}
5699 session. This means that next time you recreate the same environment,
5700 you could have to rebuild or re-download packages. @xref{Invoking guix
5701 gc}, for more on GC roots.
5703 @item --expression=@var{expr}
5704 @itemx -e @var{expr}
5705 Create an environment for the package or list of packages that
5706 @var{expr} evaluates to.
5708 For example, running:
5711 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5714 starts a shell with the environment for this specific variant of the
5720 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5723 starts a shell with all the base system packages available.
5725 The above commands only use the default output of the given packages.
5726 To select other outputs, two element tuples can be specified:
5729 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5732 @item --load=@var{file}
5733 @itemx -l @var{file}
5734 Create an environment for the package or list of packages that the code
5735 within @var{file} evaluates to.
5737 As an example, @var{file} might contain a definition like this
5738 (@pxref{Defining Packages}):
5741 @verbatiminclude environment-gdb.scm
5744 @item --manifest=@var{file}
5745 @itemx -m @var{file}
5746 Create an environment for the packages contained in the manifest object
5747 returned by the Scheme code in @var{file}. This option can be repeated
5748 several times, in which case the manifests are concatenated.
5750 This is similar to the same-named option in @command{guix package}
5751 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5755 Include all specified packages in the resulting environment, as if an
5756 @i{ad hoc} package were defined with them as inputs. This option is
5757 useful for quickly creating an environment without having to write a
5758 package expression to contain the desired inputs.
5760 For instance, the command:
5763 guix environment --ad-hoc guile guile-sdl -- guile
5766 runs @command{guile} in an environment where Guile and Guile-SDL are
5769 Note that this example implicitly asks for the default output of
5770 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5771 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5772 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5774 This option may be composed with the default behavior of @command{guix
5775 environment}. Packages appearing before @option{--ad-hoc} are
5776 interpreted as packages whose dependencies will be added to the
5777 environment, the default behavior. Packages appearing after are
5778 interpreted as packages that will be added to the environment directly.
5781 Unset existing environment variables when building the new environment, except
5782 those specified with @option{--preserve} (see below). This has the effect of
5783 creating an environment in which search paths only contain package inputs.
5785 @item --preserve=@var{regexp}
5786 @itemx -E @var{regexp}
5787 When used alongside @option{--pure}, preserve the environment variables
5788 matching @var{regexp}---in other words, put them on a ``white list'' of
5789 environment variables that must be preserved. This option can be repeated
5793 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5797 This example runs @command{mpirun} in a context where the only environment
5798 variables defined are @env{PATH}, environment variables whose name starts
5799 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5802 @item --search-paths
5803 Display the environment variable definitions that make up the
5806 @item --system=@var{system}
5807 @itemx -s @var{system}
5808 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5813 Run @var{command} within an isolated container. The current working
5814 directory outside the container is mapped inside the container.
5815 Additionally, unless overridden with @option{--user}, a dummy home
5816 directory is created that matches the current user's home directory, and
5817 @file{/etc/passwd} is configured accordingly.
5819 The spawned process runs as the current user outside the container. Inside
5820 the container, it has the same UID and GID as the current user, unless
5821 @option{--user} is passed (see below).
5825 For containers, share the network namespace with the host system.
5826 Containers created without this flag only have access to the loopback
5829 @item --link-profile
5831 For containers, link the environment profile to @file{~/.guix-profile}
5832 within the container and set @code{GUIX_ENVIRONMENT} to that.
5833 This is equivalent to making @file{~/.guix-profile} a symlink to the
5834 actual profile within the container.
5835 Linking will fail and abort the environment if the directory already
5836 exists, which will certainly be the case if @command{guix environment}
5837 was invoked in the user's home directory.
5839 Certain packages are configured to look in @file{~/.guix-profile} for
5840 configuration files and data;@footnote{For example, the
5841 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5842 for additional fonts.} @option{--link-profile} allows these programs to
5843 behave as expected within the environment.
5845 @item --user=@var{user}
5846 @itemx -u @var{user}
5847 For containers, use the username @var{user} in place of the current
5848 user. The generated @file{/etc/passwd} entry within the container will
5849 contain the name @var{user}, the home directory will be
5850 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5851 the UID and GID inside the container are 1000. @var{user}
5852 need not exist on the system.
5854 Additionally, any shared or exposed path (see @option{--share} and
5855 @option{--expose} respectively) whose target is within the current user's
5856 home directory will be remapped relative to @file{/home/USER}; this
5857 includes the automatic mapping of the current working directory.
5860 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5862 guix environment --container --user=foo \
5863 --expose=$HOME/test \
5864 --expose=/tmp/target=$HOME/target
5867 While this will limit the leaking of user identity through home paths
5868 and each of the user fields, this is only one useful component of a
5869 broader privacy/anonymity solution---not one in and of itself.
5872 For containers, the default behavior is to share the current working
5873 directory with the isolated container and immediately change to that
5874 directory within the container. If this is undesirable,
5875 @option{--no-cwd} will cause the current working directory to @emph{not}
5876 be automatically shared and will change to the user's home directory
5877 within the container instead. See also @option{--user}.
5879 @item --expose=@var{source}[=@var{target}]
5880 @itemx --share=@var{source}[=@var{target}]
5881 For containers, @option{--expose} (resp. @option{--share}) exposes the
5882 file system @var{source} from the host system as the read-only
5883 (resp. writable) file system @var{target} within the container. If
5884 @var{target} is not specified, @var{source} is used as the target mount
5885 point in the container.
5887 The example below spawns a Guile REPL in a container in which the user's
5888 home directory is accessible read-only via the @file{/exchange}
5892 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5897 @command{guix environment}
5898 also supports all of the common build options that @command{guix
5899 build} supports (@pxref{Common Build Options}) as well as package
5900 transformation options (@pxref{Package Transformation Options}).
5902 @node Invoking guix pack
5903 @section Invoking @command{guix pack}
5905 Occasionally you want to pass software to people who are not (yet!)
5906 lucky enough to be using Guix. You'd tell them to run @command{guix
5907 package -i @var{something}}, but that's not possible in this case. This
5908 is where @command{guix pack} comes in.
5911 If you are looking for ways to exchange binaries among machines that
5912 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5913 publish}, and @ref{Invoking guix archive}.
5918 @cindex application bundle
5919 @cindex software bundle
5920 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5921 @dfn{software bundle}: it creates a tarball or some other archive
5922 containing the binaries of the software you're interested in, and all
5923 its dependencies. The resulting archive can be used on any machine that
5924 does not have Guix, and people can run the exact same binaries as those
5925 you have with Guix. The pack itself is created in a bit-reproducible
5926 fashion, so anyone can verify that it really contains the build results
5927 that you pretend to be shipping.
5929 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5930 their dependencies, you can run:
5933 $ guix pack guile emacs emacs-geiser
5935 /gnu/store/@dots{}-pack.tar.gz
5938 The result here is a tarball containing a @file{/gnu/store} directory
5939 with all the relevant packages. The resulting tarball contains a
5940 @dfn{profile} with the three packages of interest; the profile is the
5941 same as would be created by @command{guix package -i}. It is this
5942 mechanism that is used to create Guix's own standalone binary tarball
5943 (@pxref{Binary Installation}).
5945 Users of this pack would have to run
5946 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5947 find inconvenient. To work around it, you can create, say, a
5948 @file{/opt/gnu/bin} symlink to the profile:
5951 guix pack -S /opt/gnu/bin=bin guile emacs emacs-geiser
5955 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5957 @cindex relocatable binaries, with @command{guix pack}
5958 What if the recipient of your pack does not have root privileges on
5959 their machine, and thus cannot unpack it in the root file system? In
5960 that case, you will want to use the @option{--relocatable} option (see
5961 below). This option produces @dfn{relocatable binaries}, meaning they
5962 they can be placed anywhere in the file system hierarchy: in the example
5963 above, users can unpack your tarball in their home directory and
5964 directly run @file{./opt/gnu/bin/guile}.
5966 @cindex Docker, build an image with guix pack
5967 Alternatively, you can produce a pack in the Docker image format using
5968 the following command:
5971 guix pack -f docker -S /bin=bin guile guile-readline
5975 The result is a tarball that can be passed to the @command{docker load}
5976 command, followed by @code{docker run}:
5979 docker load < @var{file}
5980 docker run -ti guile-guile-readline /bin/guile
5984 where @var{file} is the image returned by @var{guix pack}, and
5985 @code{guile-guile-readline} is its ``image tag''. See the
5986 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5987 documentation} for more information.
5989 @cindex Singularity, build an image with guix pack
5990 @cindex SquashFS, build an image with guix pack
5991 Yet another option is to produce a SquashFS image with the following
5995 guix pack -f squashfs bash guile emacs emacs-geiser
5999 The result is a SquashFS file system image that can either be mounted or
6000 directly be used as a file system container image with the
6001 @uref{https://www.sylabs.io/docs/, Singularity container execution
6002 environment}, using commands like @command{singularity shell} or
6003 @command{singularity exec}.
6005 Several command-line options allow you to customize your pack:
6008 @item --format=@var{format}
6009 @itemx -f @var{format}
6010 Produce a pack in the given @var{format}.
6012 The available formats are:
6016 This is the default format. It produces a tarball containing all the
6017 specified binaries and symlinks.
6020 This produces a tarball that follows the
6021 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
6022 Docker Image Specification}. The ``repository name'' as it appears in
6023 the output of the @command{docker images} command is computed from
6024 package names passed on the command line or in the manifest file.
6027 This produces a SquashFS image containing all the specified binaries and
6028 symlinks, as well as empty mount points for virtual file systems like
6032 This produces a Debian archive (a package with the @samp{.deb} file
6033 extension) containing all the specified binaries and symbolic links,
6034 that can be installed on top of any dpkg-based GNU/Linux distribution.
6037 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
6038 For that reason, @command{guix pack -f squashfs} always implies @code{-S
6039 /bin=bin}. Thus, your @command{guix pack} invocation must always start
6040 with something like:
6043 guix pack -f squashfs bash @dots{}
6046 If you forget the @code{bash} (or similar) package, @command{singularity
6047 run} and @command{singularity exec} will fail with an unhelpful ``no
6048 such file or directory'' message.
6052 @cindex relocatable binaries
6055 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
6056 anywhere in the file system hierarchy and run from there.
6058 When this option is passed once, the resulting binaries require support for
6059 @dfn{user namespaces} in the kernel Linux; when passed
6060 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
6061 PRoot support, can be thought of as the abbreviation of ``Really
6062 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
6063 other techniques if user namespaces are unavailable, and essentially
6064 work anywhere---see below for the implications.
6066 For example, if you create a pack containing Bash with:
6069 guix pack -RR -S /mybin=bin bash
6073 ...@: you can copy that pack to a machine that lacks Guix, and from your
6074 home directory as a normal user, run:
6082 In that shell, if you type @code{ls /gnu/store}, you'll notice that
6083 @file{/gnu/store} shows up and contains all the dependencies of
6084 @code{bash}, even though the machine actually lacks @file{/gnu/store}
6085 altogether! That is probably the simplest way to deploy Guix-built
6086 software on a non-Guix machine.
6089 By default, relocatable binaries rely on the @dfn{user namespace} feature of
6090 the kernel Linux, which allows unprivileged users to mount or change root.
6091 Old versions of Linux did not support it, and some GNU/Linux distributions
6094 To produce relocatable binaries that work even in the absence of user
6095 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
6096 case, binaries will try user namespace support and fall back to another
6097 @dfn{execution engine} if user namespaces are not supported. The
6098 following execution engines are supported:
6102 Try user namespaces and fall back to PRoot if user namespaces are not
6103 supported (see below).
6106 Try user namespaces and fall back to Fakechroot if user namespaces are
6107 not supported (see below).
6110 Run the program through user namespaces and abort if they are not
6114 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
6115 provides the necessary
6116 support for file system virtualization. It achieves that by using the
6117 @code{ptrace} system call on the running program. This approach has the
6118 advantage to work without requiring special kernel support, but it incurs
6119 run-time overhead every time a system call is made.
6122 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
6123 Fakechroot} virtualizes file system accesses by intercepting calls to C
6124 library functions such as @code{open}, @code{stat}, @code{exec}, and so
6125 on. Unlike PRoot, it incurs very little overhead. However, it does not
6126 always work: for example, some file system accesses made from within the
6127 C library are not intercepted, and file system accesses made @i{via}
6128 direct syscalls are not intercepted either, leading to erratic behavior.
6131 @vindex GUIX_EXECUTION_ENGINE
6132 When running a wrapped program, you can explicitly request one of the
6133 execution engines listed above by setting the
6134 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
6137 @cindex entry point, for Docker images
6138 @item --entry-point=@var{command}
6139 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6140 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6141 support it. @var{command} must be relative to the profile contained in the
6144 The entry point specifies the command that tools like @code{docker run} or
6145 @code{singularity run} automatically start by default. For example, you can
6149 guix pack -f docker --entry-point=bin/guile guile
6152 The resulting pack can easily be loaded and @code{docker run} with no extra
6153 arguments will spawn @code{bin/guile}:
6156 docker load -i pack.tar.gz
6157 docker run @var{image-id}
6160 @item --expression=@var{expr}
6161 @itemx -e @var{expr}
6162 Consider the package @var{expr} evaluates to.
6164 This has the same purpose as the same-named option in @command{guix
6165 build} (@pxref{Additional Build Options, @option{--expression} in
6166 @command{guix build}}).
6168 @item --manifest=@var{file}
6169 @itemx -m @var{file}
6170 Use the packages contained in the manifest object returned by the Scheme
6171 code in @var{file}. This option can be repeated several times, in which
6172 case the manifests are concatenated.
6174 This has a similar purpose as the same-named option in @command{guix
6175 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6176 same manifest files. It allows you to define a collection of packages
6177 once and use it both for creating profiles and for creating archives
6178 for use on machines that do not have Guix installed. Note that you can
6179 specify @emph{either} a manifest file @emph{or} a list of packages,
6182 @item --system=@var{system}
6183 @itemx -s @var{system}
6184 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6185 the system type of the build host.
6187 @item --target=@var{triplet}
6188 @cindex cross-compilation
6189 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6190 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6191 configuration triplets,, autoconf, Autoconf}).
6193 @item --compression=@var{tool}
6194 @itemx -C @var{tool}
6195 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6196 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6199 @item --symlink=@var{spec}
6200 @itemx -S @var{spec}
6201 Add the symlinks specified by @var{spec} to the pack. This option can
6202 appear several times.
6204 @var{spec} has the form @code{@var{source}=@var{target}}, where
6205 @var{source} is the symlink that will be created and @var{target} is the
6208 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6209 symlink pointing to the @file{bin} sub-directory of the profile.
6211 @item --save-provenance
6212 Save provenance information for the packages passed on the command line.
6213 Provenance information includes the URL and commit of the channels in use
6216 Provenance information is saved in the
6217 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6218 usual package metadata---the name and version of each package, their
6219 propagated inputs, and so on. It is useful information to the recipient of
6220 the pack, who then knows how the pack was (supposedly) obtained.
6222 This option is not enabled by default because, like timestamps, provenance
6223 information contributes nothing to the build process. In other words, there
6224 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6225 Recording such ``silent'' metadata in the output thus potentially breaks the
6226 source-to-binary bitwise reproducibility property.
6228 @item --root=@var{file}
6229 @itemx -r @var{file}
6230 @cindex garbage collector root, for packs
6231 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6234 @item --localstatedir
6235 @itemx --profile-name=@var{name}
6236 Include the ``local state directory'', @file{/var/guix}, in the resulting
6237 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6238 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6239 @file{~root/.guix-profile}.
6241 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6242 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6243 the pack means that the store is ``complete'' and manageable by Guix;
6244 not providing it pack means that the store is ``dead'': items cannot be
6245 added to it or removed from it after extraction of the pack.
6247 One use case for this is the Guix self-contained binary tarball
6248 (@pxref{Binary Installation}).
6252 Print the name of the derivation that builds the pack.
6255 Use the bootstrap binaries to build the pack. This option is only
6256 useful to Guix developers.
6259 In addition, @command{guix pack} supports all the common build options
6260 (@pxref{Common Build Options}) and all the package transformation
6261 options (@pxref{Package Transformation Options}).
6264 @node The GCC toolchain
6265 @section The GCC toolchain
6269 @cindex linker wrapper
6270 @cindex toolchain, for C development
6271 @cindex toolchain, for Fortran development
6273 If you need a complete toolchain for compiling and linking C or C++
6274 source code, use the @code{gcc-toolchain} package. This package
6275 provides a complete GCC toolchain for C/C++ development, including GCC
6276 itself, the GNU C Library (headers and binaries, plus debugging symbols
6277 in the @code{debug} output), Binutils, and a linker wrapper.
6279 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6280 passed to the linker, add corresponding @code{-rpath} arguments, and
6281 invoke the actual linker with this new set of arguments. You can instruct the
6282 wrapper to refuse to link against libraries not in the store by setting the
6283 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6285 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6286 for Fortran development. For other languages, please use
6287 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6290 @node Invoking guix git authenticate
6291 @section Invoking @command{guix git authenticate}
6293 The @command{guix git authenticate} command authenticates a Git checkout
6294 following the same rule as for channels (@pxref{channel-authentication,
6295 channel authentication}). That is, starting from a given commit, it
6296 ensures that all subsequent commits are signed by an OpenPGP key whose
6297 fingerprint appears in the @file{.guix-authorizations} file of its
6300 You will find this command useful if you maintain a channel. But in
6301 fact, this authentication mechanism is useful in a broader context, so
6302 you might want to use it for Git repositories that have nothing to do
6305 The general syntax is:
6308 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6311 By default, this command authenticates the Git checkout in the current
6312 directory; it outputs nothing and exits with exit code zero on success
6313 and non-zero on failure. @var{commit} above denotes the first commit
6314 where authentication takes place, and @var{signer} is the OpenPGP
6315 fingerprint of public key used to sign @var{commit}. Together, they
6316 form a ``channel introduction'' (@pxref{channel-authentication, channel
6317 introduction}). The options below allow you to fine-tune the process.
6320 @item --repository=@var{directory}
6321 @itemx -r @var{directory}
6322 Open the Git repository in @var{directory} instead of the current
6325 @item --keyring=@var{reference}
6326 @itemx -k @var{reference}
6327 Load OpenPGP keyring from @var{reference}, the reference of a branch
6328 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6329 contain OpenPGP public keys in @file{.key} files, either in binary form
6330 or ``ASCII-armored''. By default the keyring is loaded from the branch
6331 named @code{keyring}.
6334 Display commit signing statistics upon completion.
6336 @item --cache-key=@var{key}
6337 Previously-authenticated commits are cached in a file under
6338 @file{~/.cache/guix/authentication}. This option forces the cache to be
6339 stored in file @var{key} in that directory.
6341 @item --historical-authorizations=@var{file}
6342 By default, any commit whose parent commit(s) lack the
6343 @file{.guix-authorizations} file is considered inauthentic. In
6344 contrast, this option considers the authorizations in @var{file} for any
6345 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6346 is the same as that of @file{.guix-authorizations}
6347 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6351 @c *********************************************************************
6352 @node Programming Interface
6353 @chapter Programming Interface
6355 GNU Guix provides several Scheme programming interfaces (APIs) to
6356 define, build, and query packages. The first interface allows users to
6357 write high-level package definitions. These definitions refer to
6358 familiar packaging concepts, such as the name and version of a package,
6359 its build system, and its dependencies. These definitions can then be
6360 turned into concrete build actions.
6362 Build actions are performed by the Guix daemon, on behalf of users. In a
6363 standard setup, the daemon has write access to the store---the
6364 @file{/gnu/store} directory---whereas users do not. The recommended
6365 setup also has the daemon perform builds in chroots, under specific
6366 build users, to minimize interference with the rest of the system.
6369 Lower-level APIs are available to interact with the daemon and the
6370 store. To instruct the daemon to perform a build action, users actually
6371 provide it with a @dfn{derivation}. A derivation is a low-level
6372 representation of the build actions to be taken, and the environment in
6373 which they should occur---derivations are to package definitions what
6374 assembly is to C programs. The term ``derivation'' comes from the fact
6375 that build results @emph{derive} from them.
6377 This chapter describes all these APIs in turn, starting from high-level
6378 package definitions.
6381 * Package Modules:: Packages from the programmer's viewpoint.
6382 * Defining Packages:: Defining new packages.
6383 * Defining Package Variants:: Customizing packages.
6384 * Build Systems:: Specifying how packages are built.
6385 * Build Phases:: Phases of the build process of a package.
6386 * Build Utilities:: Helpers for your package definitions and more.
6387 * The Store:: Manipulating the package store.
6388 * Derivations:: Low-level interface to package derivations.
6389 * The Store Monad:: Purely functional interface to the store.
6390 * G-Expressions:: Manipulating build expressions.
6391 * Invoking guix repl:: Programming Guix in Guile
6394 @node Package Modules
6395 @section Package Modules
6397 From a programming viewpoint, the package definitions of the
6398 GNU distribution are provided by Guile modules in the @code{(gnu packages
6399 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6400 packages @dots{})} module name space are not necessarily ``GNU
6401 packages''. This module naming scheme follows the usual Guile module
6402 naming convention: @code{gnu} means that these modules are distributed
6403 as part of the GNU system, and @code{packages} identifies modules that
6404 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6405 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6406 module exports a variable named @code{emacs}, which is bound to a
6407 @code{<package>} object (@pxref{Defining Packages}).
6409 The @code{(gnu packages @dots{})} module name space is
6410 automatically scanned for packages by the command-line tools. For
6411 instance, when running @code{guix install emacs}, all the @code{(gnu
6412 packages @dots{})} modules are scanned until one that exports a package
6413 object whose name is @code{emacs} is found. This package search
6414 facility is implemented in the @code{(gnu packages)} module.
6416 @cindex customization, of packages
6417 @cindex package module search path
6418 Users can store package definitions in modules with different
6419 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6420 name and module name must match. For instance, the @code{(my-packages
6421 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6422 relative to the load path specified with @option{--load-path} or
6423 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6424 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6425 these package definitions visible to the user interfaces:
6429 By adding the directory containing your package modules to the search path
6430 with the @code{-L} flag of @command{guix package} and other commands
6431 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6432 environment variable described below.
6435 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6436 pulls from it. A channel is essentially a Git repository containing package
6437 modules. @xref{Channels}, for more information on how to define and use
6441 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6443 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6444 This is a colon-separated list of directories to search for additional
6445 package modules. Directories listed in this variable take precedence
6446 over the own modules of the distribution.
6449 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6450 each package is built based solely on other packages in the
6451 distribution. The root of this dependency graph is a small set of
6452 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6453 bootstrap)} module. For more information on bootstrapping,
6454 @pxref{Bootstrapping}.
6456 @node Defining Packages
6457 @section Defining Packages
6459 The high-level interface to package definitions is implemented in the
6460 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6461 example, the package definition, or @dfn{recipe}, for the GNU Hello
6462 package looks like this:
6465 (define-module (gnu packages hello)
6466 #:use-module (guix packages)
6467 #:use-module (guix download)
6468 #:use-module (guix build-system gnu)
6469 #:use-module (guix licenses)
6470 #:use-module (gnu packages gawk))
6472 (define-public hello
6478 (uri (string-append "mirror://gnu/hello/hello-" version
6482 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6483 (build-system gnu-build-system)
6484 (arguments '(#:configure-flags '("--enable-silent-rules")))
6485 (inputs `(("gawk" ,gawk)))
6486 (synopsis "Hello, GNU world: An example GNU package")
6487 (description "Guess what GNU Hello prints!")
6488 (home-page "https://www.gnu.org/software/hello/")
6493 Without being a Scheme expert, the reader may have guessed the meaning
6494 of the various fields here. This expression binds the variable
6495 @code{hello} to a @code{<package>} object, which is essentially a record
6496 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6497 This package object can be inspected using procedures found in the
6498 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6499 returns---surprise!---@code{"hello"}.
6501 With luck, you may be able to import part or all of the definition of
6502 the package you are interested in from another repository, using the
6503 @code{guix import} command (@pxref{Invoking guix import}).
6505 In the example above, @code{hello} is defined in a module of its own,
6506 @code{(gnu packages hello)}. Technically, this is not strictly
6507 necessary, but it is convenient to do so: all the packages defined in
6508 modules under @code{(gnu packages @dots{})} are automatically known to
6509 the command-line tools (@pxref{Package Modules}).
6511 There are a few points worth noting in the above package definition:
6515 The @code{source} field of the package is an @code{<origin>} object
6516 (@pxref{origin Reference}, for the complete reference).
6517 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6518 meaning that the source is a file to be downloaded over FTP or HTTP.
6520 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6521 the GNU mirrors defined in @code{(guix download)}.
6523 The @code{sha256} field specifies the expected SHA256 hash of the file
6524 being downloaded. It is mandatory, and allows Guix to check the
6525 integrity of the file. The @code{(base32 @dots{})} form introduces the
6526 base32 representation of the hash. You can obtain this information with
6527 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6528 hash} (@pxref{Invoking guix hash}).
6531 When needed, the @code{origin} form can also have a @code{patches} field
6532 listing patches to be applied, and a @code{snippet} field giving a
6533 Scheme expression to modify the source code.
6536 @cindex GNU Build System
6537 The @code{build-system} field specifies the procedure to build the
6538 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6539 represents the familiar GNU Build System, where packages may be
6540 configured, built, and installed with the usual @code{./configure &&
6541 make && make check && make install} command sequence.
6543 When you start packaging non-trivial software, you may need tools to
6544 manipulate those build phases, manipulate files, and so on. @xref{Build
6545 Utilities}, for more on this.
6548 The @code{arguments} field specifies options for the build system
6549 (@pxref{Build Systems}). Here it is interpreted by
6550 @code{gnu-build-system} as a request run @file{configure} with the
6551 @option{--enable-silent-rules} flag.
6557 What about these quote (@code{'}) characters? They are Scheme syntax to
6558 introduce a literal list; @code{'} is synonymous with @code{quote}.
6559 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6560 for details. Here the value of the @code{arguments} field is a list of
6561 arguments passed to the build system down the road, as with @code{apply}
6562 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6565 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6566 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6567 @code{#:configure-flags} is a keyword used to pass a keyword argument
6568 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6572 The @code{inputs} field specifies inputs to the build process---i.e.,
6573 build-time or run-time dependencies of the package. Here, we define an
6574 input called @code{"gawk"} whose value is that of the @code{gawk}
6575 variable; @code{gawk} is itself bound to a @code{<package>} object.
6577 @cindex backquote (quasiquote)
6580 @cindex comma (unquote)
6584 @findex unquote-splicing
6585 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6586 us to introduce a literal list in the @code{inputs} field, while
6587 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6588 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6591 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6592 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6593 of ensuring that they are present (@pxref{Build Systems}).
6595 However, any other dependencies need to be specified in the
6596 @code{inputs} field. Any dependency not specified here will simply be
6597 unavailable to the build process, possibly leading to a build failure.
6600 @xref{package Reference}, for a full description of possible fields.
6602 Once a package definition is in place, the
6603 package may actually be built using the @code{guix build} command-line
6604 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6605 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6606 package definition using the @command{guix edit} command
6607 (@pxref{Invoking guix edit}).
6608 @xref{Packaging Guidelines}, for
6609 more information on how to test package definitions, and
6610 @ref{Invoking guix lint}, for information on how to check a definition
6611 for style conformance.
6612 @vindex GUIX_PACKAGE_PATH
6613 Lastly, @pxref{Channels}, for information
6614 on how to extend the distribution by adding your own package definitions
6617 Finally, updating the package definition to a new upstream version
6618 can be partly automated by the @command{guix refresh} command
6619 (@pxref{Invoking guix refresh}).
6621 Behind the scenes, a derivation corresponding to the @code{<package>}
6622 object is first computed by the @code{package-derivation} procedure.
6623 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6624 The build actions it prescribes may then be realized by using the
6625 @code{build-derivations} procedure (@pxref{The Store}).
6627 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6628 Return the @code{<derivation>} object of @var{package} for @var{system}
6629 (@pxref{Derivations}).
6631 @var{package} must be a valid @code{<package>} object, and @var{system}
6632 must be a string denoting the target system type---e.g.,
6633 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6634 must be a connection to the daemon, which operates on the store
6635 (@pxref{The Store}).
6639 @cindex cross-compilation
6640 Similarly, it is possible to compute a derivation that cross-builds a
6641 package for some other system:
6643 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6644 @var{package} @var{target} [@var{system}]
6645 Return the @code{<derivation>} object of @var{package} cross-built from
6646 @var{system} to @var{target}.
6648 @var{target} must be a valid GNU triplet denoting the target hardware
6649 and operating system, such as @code{"aarch64-linux-gnu"}
6650 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6653 Once you have package definitions, you can easily define @emph{variants}
6654 of those packages. @xref{Defining Package Variants}, for more on that.
6657 * package Reference:: The package data type.
6658 * origin Reference:: The origin data type.
6662 @node package Reference
6663 @subsection @code{package} Reference
6665 This section summarizes all the options available in @code{package}
6666 declarations (@pxref{Defining Packages}).
6668 @deftp {Data Type} package
6669 This is the data type representing a package recipe.
6673 The name of the package, as a string.
6675 @item @code{version}
6676 The version of the package, as a string. @xref{Version Numbers}, for
6680 An object telling how the source code for the package should be
6681 acquired. Most of the time, this is an @code{origin} object, which
6682 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6683 can also be any other ``file-like'' object such as a @code{local-file},
6684 which denotes a file from the local file system (@pxref{G-Expressions,
6685 @code{local-file}}).
6687 @item @code{build-system}
6688 The build system that should be used to build the package (@pxref{Build
6691 @item @code{arguments} (default: @code{'()})
6692 The arguments that should be passed to the build system. This is a
6693 list, typically containing sequential keyword-value pairs.
6695 @item @code{inputs} (default: @code{'()})
6696 @itemx @code{native-inputs} (default: @code{'()})
6697 @itemx @code{propagated-inputs} (default: @code{'()})
6698 @cindex inputs, of packages
6699 These fields list dependencies of the package. Each one is a list of
6700 tuples, where each tuple has a label for the input (a string) as its
6701 first element, a package, origin, or derivation as its second element,
6702 and optionally the name of the output thereof that should be used, which
6703 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6704 more on package outputs). For example, the list below specifies three
6708 `(("libffi" ,libffi)
6709 ("libunistring" ,libunistring)
6710 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6713 @cindex cross compilation, package dependencies
6714 The distinction between @code{native-inputs} and @code{inputs} is
6715 necessary when considering cross-compilation. When cross-compiling,
6716 dependencies listed in @code{inputs} are built for the @emph{target}
6717 architecture; conversely, dependencies listed in @code{native-inputs}
6718 are built for the architecture of the @emph{build} machine.
6720 @code{native-inputs} is typically used to list tools needed at
6721 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6722 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6723 this area (@pxref{Invoking guix lint}).
6725 @anchor{package-propagated-inputs}
6726 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6727 specified packages will be automatically installed to profiles
6728 (@pxref{Features, the role of profiles in Guix}) alongside the package
6729 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6730 package}}, for information on how @command{guix package} deals with
6733 For example this is necessary when packaging a C/C++ library that needs
6734 headers of another library to compile, or when a pkg-config file refers
6735 to another one @i{via} its @code{Requires} field.
6737 Another example where @code{propagated-inputs} is useful is for languages
6738 that lack a facility to record the run-time search path akin to the
6739 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6740 more. When packaging libraries written in those languages, ensure they
6741 can find library code they depend on at run time by listing run-time
6742 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6744 @item @code{outputs} (default: @code{'("out")})
6745 The list of output names of the package. @xref{Packages with Multiple
6746 Outputs}, for typical uses of additional outputs.
6748 @item @code{native-search-paths} (default: @code{'()})
6749 @itemx @code{search-paths} (default: @code{'()})
6750 A list of @code{search-path-specification} objects describing
6751 search-path environment variables honored by the package.
6753 @item @code{replacement} (default: @code{#f})
6754 This must be either @code{#f} or a package object that will be used as a
6755 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6758 @item @code{synopsis}
6759 A one-line description of the package.
6761 @item @code{description}
6762 A more elaborate description of the package.
6764 @item @code{license}
6765 @cindex license, of packages
6766 The license of the package; a value from @code{(guix licenses)},
6767 or a list of such values.
6769 @item @code{home-page}
6770 The URL to the home-page of the package, as a string.
6772 @item @code{supported-systems} (default: @code{%supported-systems})
6773 The list of systems supported by the package, as strings of the form
6774 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6776 @item @code{location} (default: source location of the @code{package} form)
6777 The source location of the package. It is useful to override this when
6778 inheriting from another package, in which case this field is not
6779 automatically corrected.
6783 @deffn {Scheme Syntax} this-package
6784 When used in the @emph{lexical scope} of a package field definition, this
6785 identifier resolves to the package being defined.
6787 The example below shows how to add a package as a native input of itself when
6795 ;; When cross-compiled, Guile, for example, depends on
6796 ;; a native version of itself. Add it here.
6797 (native-inputs (if (%current-target-system)
6798 `(("self" ,this-package))
6802 It is an error to refer to @code{this-package} outside a package definition.
6805 Because packages are regular Scheme objects that capture a complete
6806 dependency graph and associated build procedures, it is often useful to
6807 write procedures that take a package and return a modified version
6808 thereof according to some parameters. Below are a few examples.
6810 @cindex tool chain, choosing a package's tool chain
6811 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6812 Return a variant of @var{package} that uses @var{toolchain} instead of
6813 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6814 inputs (label/package tuples) providing equivalent functionality, such
6815 as the @code{gcc-toolchain} package.
6817 The example below returns a variant of the @code{hello} package built
6818 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6819 GNU C Library) instead of the default tool chain:
6822 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6823 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6826 The build tool chain is part of the @dfn{implicit inputs} of
6827 packages---it's usually not listed as part of the various ``inputs''
6828 fields and is instead pulled in by the build system. Consequently, this
6829 procedure works by changing the build system of @var{package} so that it
6830 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6831 for more on build systems.
6834 @node origin Reference
6835 @subsection @code{origin} Reference
6837 This section documents @dfn{origins}. An @code{origin} declaration
6838 specifies data that must be ``produced''---downloaded, usually---and
6839 whose content hash is known in advance. Origins are primarily used to
6840 represent the source code of packages (@pxref{Defining Packages}). For
6841 that reason, the @code{origin} form allows you to declare patches to
6842 apply to the original source code as well as code snippets to modify it.
6844 @deftp {Data Type} origin
6845 This is the data type representing a source code origin.
6849 An object containing the URI of the source. The object type depends on
6850 the @code{method} (see below). For example, when using the
6851 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6852 values are: a URL represented as a string, or a list thereof.
6854 @cindex fixed-output derivations, for download
6856 A monadic procedure that handles the given URI@. The procedure must
6857 accept at least three arguments: the value of the @code{uri} field and
6858 the hash algorithm and hash value specified by the @code{hash} field.
6859 It must return a store item or a derivation in the store monad
6860 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6861 (@pxref{Derivations}).
6863 Commonly used methods include @code{url-fetch}, which fetches data from
6864 a URL, and @code{git-fetch}, which fetches data from a Git repository
6868 A bytevector containing the SHA-256 hash of the source. This is
6869 equivalent to providing a @code{content-hash} SHA256 object in the
6870 @code{hash} field described below.
6873 The @code{content-hash} object of the source---see below for how to use
6874 @code{content-hash}.
6876 You can obtain this information using @code{guix download}
6877 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6880 @item @code{file-name} (default: @code{#f})
6881 The file name under which the source code should be saved. When this is
6882 @code{#f}, a sensible default value will be used in most cases. In case
6883 the source is fetched from a URL, the file name from the URL will be
6884 used. For version control checkouts, it is recommended to provide the
6885 file name explicitly because the default is not very descriptive.
6887 @item @code{patches} (default: @code{'()})
6888 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6889 file-like objects}) pointing to patches to be applied to the source.
6891 This list of patches must be unconditional. In particular, it cannot
6892 depend on the value of @code{%current-system} or
6893 @code{%current-target-system}.
6895 @item @code{snippet} (default: @code{#f})
6896 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6897 in the source directory. This is a convenient way to modify the source,
6898 sometimes more convenient than a patch.
6900 @item @code{patch-flags} (default: @code{'("-p1")})
6901 A list of command-line flags that should be passed to the @code{patch}
6904 @item @code{patch-inputs} (default: @code{#f})
6905 Input packages or derivations to the patching process. When this is
6906 @code{#f}, the usual set of inputs necessary for patching are provided,
6907 such as GNU@tie{}Patch.
6909 @item @code{modules} (default: @code{'()})
6910 A list of Guile modules that should be loaded during the patching
6911 process and while running the code in the @code{snippet} field.
6913 @item @code{patch-guile} (default: @code{#f})
6914 The Guile package that should be used in the patching process. When
6915 this is @code{#f}, a sensible default is used.
6919 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6920 Construct a content hash object for the given @var{algorithm}, and with
6921 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6922 it is @code{sha256}.
6924 @var{value} can be a literal string, in which case it is base32-decoded,
6925 or it can be a bytevector.
6927 The following forms are all equivalent:
6930 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6931 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6933 (content-hash (base32
6934 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6935 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6939 Technically, @code{content-hash} is currently implemented as a macro.
6940 It performs sanity checks at macro-expansion time, when possible, such
6941 as ensuring that @var{value} has the right size for @var{algorithm}.
6944 As we have seen above, how exactly the data an origin refers to is
6945 retrieved is determined by its @code{method} field. The @code{(guix
6946 download)} module provides the most common method, @code{url-fetch},
6949 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6950 [name] [#:executable? #f]
6951 Return a fixed-output derivation that fetches data from @var{url} (a
6952 string, or a list of strings denoting alternate URLs), which is expected
6953 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6954 the file name is the base name of URL; optionally, @var{name} can
6955 specify a different file name. When @var{executable?} is true, make the
6956 downloaded file executable.
6958 When one of the URL starts with @code{mirror://}, then its host part is
6959 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6961 Alternatively, when URL starts with @code{file://}, return the
6962 corresponding file name in the store.
6965 Likewise, the @code{(guix git-download)} module defines the
6966 @code{git-fetch} origin method, which fetches data from a Git version
6967 control repository, and the @code{git-reference} data type to describe
6968 the repository and revision to fetch.
6970 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6971 Return a fixed-output derivation that fetches @var{ref}, a
6972 @code{<git-reference>} object. The output is expected to have recursive
6973 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6974 the file name, or a generic name if @code{#f}.
6977 @deftp {Data Type} git-reference
6978 This data type represents a Git reference for @code{git-fetch} to
6983 The URL of the Git repository to clone.
6986 This string denotes either the commit to fetch (a hexadecimal string,
6987 either the full SHA1 commit or a ``short'' commit string; the latter is
6988 not recommended) or the tag to fetch.
6990 @item @code{recursive?} (default: @code{#f})
6991 This Boolean indicates whether to recursively fetch Git sub-modules.
6994 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6999 (url "https://git.savannah.gnu.org/git/hello.git")
7003 This is equivalent to the reference below, which explicitly names the
7008 (url "https://git.savannah.gnu.org/git/hello.git")
7009 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
7013 For Mercurial repositories, the module @code{(guix hg-download)} defines
7014 the @code{hg-fetch} origin method and @code{hg-reference} data type for
7015 support of the Mercurial version control system.
7017 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
7019 Return a fixed-output derivation that fetches @var{ref}, a
7020 @code{<hg-reference>} object. The output is expected to have recursive
7021 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
7022 the file name, or a generic name if @code{#false}.
7025 @node Defining Package Variants
7026 @section Defining Package Variants
7028 @cindex customizing packages
7029 @cindex variants, of packages
7030 One of the nice things with Guix is that, given a package definition,
7031 you can easily @emph{derive} variants of that package---for a different
7032 upstream version, with different dependencies, different compilation
7033 options, and so on. Some of these custom packages can be defined
7034 straight from the command line (@pxref{Package Transformation Options}).
7035 This section describes how to define package variants in code. This can
7036 be useful in ``manifests'' (@pxref{profile-manifest,
7037 @option{--manifest}}) and in your own package collection
7038 (@pxref{Creating a Channel}), among others!
7040 @cindex inherit, for package definitions
7041 As discussed earlier, packages are first-class objects in the Scheme
7042 language. The @code{(guix packages)} module provides the @code{package}
7043 construct to define new package objects (@pxref{package Reference}).
7044 The easiest way to define a package variant is using the @code{inherit}
7045 keyword together with @code{package}. This allows you to inherit from a
7046 package definition while overriding the fields you want.
7048 For example, given the @code{hello} variable, which contains a
7049 definition for the current version of GNU@tie{}Hello, here's how you
7050 would define a variant for version 2.2 (released in 2006, it's
7054 (use-modules (gnu packages base)) ;for 'hello'
7062 (uri (string-append "mirror://gnu/hello/hello-" version
7066 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
7069 The example above corresponds to what the @option{--with-source} package
7070 transformation option does. Essentially @code{hello-2.2} preserves all
7071 the fields of @code{hello}, except @code{version} and @code{source},
7072 which it overrides. Note that the original @code{hello} variable is
7073 still there, in the @code{(gnu packages base)} module, unchanged. When
7074 you define a custom package like this, you are really @emph{adding} a
7075 new package definition; the original one remains available.
7077 You can just as well define variants with a different set of
7078 dependencies than the original package. For example, the default
7079 @code{gdb} package depends on @code{guile}, but since that is an
7080 optional dependency, you can define a variant that removes that
7084 (use-modules (gnu packages gdb) ;for 'gdb'
7085 (srfi srfi-1)) ;for 'alist-delete'
7087 (define gdb-sans-guile
7090 (inputs (alist-delete "guile"
7091 (package-inputs gdb)))))
7094 The @code{alist-delete} call above removes the tuple from the
7095 @code{inputs} field that has @code{"guile"} as its first element
7096 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
7099 In some cases, you may find it useful to write functions
7100 (``procedures'', in Scheme parlance) that return a package based on some
7101 parameters. For example, consider the @code{luasocket} library for the
7102 Lua programming language. We want to create @code{luasocket} packages
7103 for major versions of Lua. One way to do that is to define a procedure
7104 that takes a Lua package and returns a @code{luasocket} package that
7108 (define (make-lua-socket name lua)
7109 ;; Return a luasocket package built with LUA.
7113 ;; several fields omitted
7116 (synopsis "Socket library for Lua")))
7118 (define-public lua5.1-socket
7119 (make-lua-socket "lua5.1-socket" lua-5.1))
7121 (define-public lua5.2-socket
7122 (make-lua-socket "lua5.2-socket" lua-5.2))
7125 Here we have defined packages @code{lua5.1-socket} and
7126 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
7127 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
7128 more info on procedures. Having top-level public definitions for these
7129 two packages means that they can be referred to from the command line
7130 (@pxref{Package Modules}).
7132 @cindex package transformations
7133 These are pretty simple package variants. As a convenience, the
7134 @code{(guix transformations)} module provides a high-level interface
7135 that directly maps to the more sophisticated package transformation
7136 options (@pxref{Package Transformation Options}):
7138 @deffn {Scheme Procedure} options->transformation @var{opts}
7139 Return a procedure that, when passed an object to build (package,
7140 derivation, etc.), applies the transformations specified by @var{opts} and returns
7141 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
7144 ((with-branch . "guile-gcrypt=master")
7145 (without-tests . "libgcrypt"))
7148 Each symbol names a transformation and the corresponding string is an argument
7149 to that transformation.
7152 For instance, a manifest equivalent to this command:
7156 --with-branch=guile-gcrypt=master \
7157 --with-debug-info=zlib
7161 ... would look like this:
7164 (use-modules (guix transformations))
7167 ;; The package transformation procedure.
7168 (options->transformation
7169 '((with-branch . "guile-gcrypt=master")
7170 (with-debug-info . "zlib"))))
7173 (list (transform (specification->package "guix"))))
7176 @cindex input rewriting
7177 @cindex dependency graph rewriting
7178 The @code{options->transformation} procedure is convenient, but it's
7179 perhaps also not as flexible as you may like. How is it implemented?
7180 The astute reader probably noticed that most package transformation
7181 options go beyond the superficial changes shown in the first examples of
7182 this section: they involve @dfn{input rewriting}, whereby the dependency
7183 graph of a package is rewritten by replacing specific inputs by others.
7185 Dependency graph rewriting, for the purposes of swapping packages in the
7186 graph, is what the @code{package-input-rewriting} procedure in
7187 @code{(guix packages)} implements.
7189 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7190 [@var{rewrite-name}] [#:deep? #t]
7191 Return a procedure that, when passed a package, replaces its direct and
7192 indirect dependencies, including implicit inputs when @var{deep?} is
7193 true, according to @var{replacements}. @var{replacements} is a list of
7194 package pairs; the first element of each pair is the package to replace,
7195 and the second one is the replacement.
7197 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7198 the name of a package and returns its new name after rewrite.
7202 Consider this example:
7205 (define libressl-instead-of-openssl
7206 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7208 (package-input-rewriting `((,openssl . ,libressl))))
7210 (define git-with-libressl
7211 (libressl-instead-of-openssl git))
7215 Here we first define a rewriting procedure that replaces @var{openssl}
7216 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7217 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7218 This is exactly what the @option{--with-input} command-line option does
7219 (@pxref{Package Transformation Options, @option{--with-input}}).
7221 The following variant of @code{package-input-rewriting} can match packages to
7222 be replaced by name rather than by identity.
7224 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7225 Return a procedure that, given a package, applies the given
7226 @var{replacements} to all the package graph, including implicit inputs
7227 unless @var{deep?} is false. @var{replacements} is a list of
7228 spec/procedures pair; each spec is a package specification such as
7229 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7230 package and returns a replacement for that package.
7233 The example above could be rewritten this way:
7236 (define libressl-instead-of-openssl
7237 ;; Replace all the packages called "openssl" with LibreSSL.
7238 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7241 The key difference here is that, this time, packages are matched by spec and
7242 not by identity. In other words, any package in the graph that is called
7243 @code{openssl} will be replaced.
7245 A more generic procedure to rewrite a package dependency graph is
7246 @code{package-mapping}: it supports arbitrary changes to nodes in the
7249 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7250 Return a procedure that, given a package, applies @var{proc} to all the packages
7251 depended on and returns the resulting package. The procedure stops recursion
7252 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7253 applied to implicit inputs as well.
7258 @section Build Systems
7260 @cindex build system
7261 Each package definition specifies a @dfn{build system} and arguments for
7262 that build system (@pxref{Defining Packages}). This @code{build-system}
7263 field represents the build procedure of the package, as well as implicit
7264 dependencies of that build procedure.
7266 Build systems are @code{<build-system>} objects. The interface to
7267 create and manipulate them is provided by the @code{(guix build-system)}
7268 module, and actual build systems are exported by specific modules.
7270 @cindex bag (low-level package representation)
7271 Under the hood, build systems first compile package objects to
7272 @dfn{bags}. A @dfn{bag} is like a package, but with less
7273 ornamentation---in other words, a bag is a lower-level representation of
7274 a package, which includes all the inputs of that package, including some
7275 that were implicitly added by the build system. This intermediate
7276 representation is then compiled to a derivation (@pxref{Derivations}).
7277 The @code{package-with-c-toolchain} is an example of a way to change the
7278 implicit inputs that a package's build system pulls in (@pxref{package
7279 Reference, @code{package-with-c-toolchain}}).
7281 Build systems accept an optional list of @dfn{arguments}. In package
7282 definitions, these are passed @i{via} the @code{arguments} field
7283 (@pxref{Defining Packages}). They are typically keyword arguments
7284 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7285 Guile Reference Manual}). The value of these arguments is usually
7286 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7287 by the daemon (@pxref{Derivations}).
7289 The main build system is @code{gnu-build-system}, which implements the
7290 standard build procedure for GNU and many other packages. It
7291 is provided by the @code{(guix build-system gnu)} module.
7293 @defvr {Scheme Variable} gnu-build-system
7294 @code{gnu-build-system} represents the GNU Build System, and variants
7295 thereof (@pxref{Configuration, configuration and makefile conventions,,
7296 standards, GNU Coding Standards}).
7298 @cindex build phases
7299 In a nutshell, packages using it are configured, built, and installed with
7300 the usual @code{./configure && make && make check && make install}
7301 command sequence. In practice, a few additional steps are often needed.
7302 All these steps are split up in separate @dfn{phases}.
7303 @xref{Build Phases}, for more info on build phases and ways to customize
7306 In addition, this build system ensures that the ``standard'' environment
7307 for GNU packages is available. This includes tools such as GCC, libc,
7308 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7309 build-system gnu)} module for a complete list). We call these the
7310 @dfn{implicit inputs} of a package, because package definitions do not
7311 have to mention them.
7313 This build system supports a number of keyword arguments, which can be
7314 passed @i{via} the @code{arguments} field of a package. Here are some
7315 of the main parameters:
7319 This argument specifies build-side code that evaluates to an alist of
7320 build phases. @xref{Build Phases}, for more information.
7322 @item #:configure-flags
7323 This is a list of flags (strings) passed to the @command{configure}
7324 script. @xref{Defining Packages}, for an example.
7327 This list of strings contains flags passed as arguments to
7328 @command{make} invocations in the @code{build}, @code{check}, and
7329 @code{install} phases.
7331 @item #:out-of-source?
7332 This Boolean, @code{#f} by default, indicates whether to run builds in a
7333 build directory separate from the source tree.
7335 When it is true, the @code{configure} phase creates a separate build
7336 directory, changes to that directory, and runs the @code{configure}
7337 script from there. This is useful for packages that require it, such as
7341 This Boolean, @code{#t} by default, indicates whether the @code{check}
7342 phase should run the package's test suite.
7345 This string, @code{"check"} by default, gives the name of the makefile
7346 target used by the @code{check} phase.
7348 @item #:parallel-build?
7349 @itemx #:parallel-tests?
7350 These Boolean values specify whether to build, respectively run the test
7351 suite, in parallel, with the @code{-j} flag of @command{make}. When
7352 they are true, @code{make} is passed @code{-j@var{n}}, where @var{n} is
7353 the number specified as the @option{--cores} option of
7354 @command{guix-daemon} or that of the @command{guix} client command
7355 (@pxref{Common Build Options, @option{--cores}}).
7357 @cindex RUNPATH, validation
7358 @item #:validate-runpath?
7359 This Boolean, @code{#t} by default, determines whether to ``validate''
7360 the @code{RUNPATH} of ELF binaries (@code{.so} shared libraries as well
7361 as executables) previously installed by the @code{install} phase.
7363 This validation step consists in making sure that all the shared
7364 libraries needed by an ELF binaries, which are listed as
7365 @code{DT_NEEDED} entries in its @code{PT_DYNAMIC} segment, appear in the
7366 @code{DT_RUNPATH} entry of that binary. In other words, it ensures that
7367 running or using those binaries will not result in a ``file not found''
7368 error at run time. @xref{Options, @option{-rpath},, ld, The GNU
7369 Linker}, for more information on @code{RUNPATH}.
7371 @item #:substitutable?
7372 This Boolean, @code{#t} by default, tells whether the package outputs
7373 should be substitutable---i.e., whether users should be able to obtain
7374 substitutes for them instead of building locally (@pxref{Substitutes}).
7376 @item #:allowed-references
7377 @itemx #:disallowed-references
7378 When true, these arguments must be a list of dependencies that must not
7379 appear among the references of the build results. If, upon build
7380 completion, some of these references are retained, the build process
7383 This is useful to ensure that a package does not erroneously keep a
7384 reference to some of it build-time inputs, in cases where doing so
7385 would, for example, unnecessarily increase its size (@pxref{Invoking
7389 Most other build systems support these keyword arguments.
7392 Other @code{<build-system>} objects are defined to support other
7393 conventions and tools used by free software packages. They inherit most
7394 of @code{gnu-build-system}, and differ mainly in the set of inputs
7395 implicitly added to the build process, and in the list of phases
7396 executed. Some of these build systems are listed below.
7398 @defvr {Scheme Variable} ant-build-system
7399 This variable is exported by @code{(guix build-system ant)}. It
7400 implements the build procedure for Java packages that can be built with
7401 @url{https://ant.apache.org/, Ant build tool}.
7403 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7404 provided by the @code{icedtea} package to the set of inputs. Different
7405 packages can be specified with the @code{#:ant} and @code{#:jdk}
7406 parameters, respectively.
7408 When the original package does not provide a suitable Ant build file,
7409 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7410 build file @file{build.xml} with tasks to build the specified jar
7411 archive. In this case the parameter @code{#:source-dir} can be used to
7412 specify the source sub-directory, defaulting to ``src''.
7414 The @code{#:main-class} parameter can be used with the minimal ant
7415 buildfile to specify the main class of the resulting jar. This makes the
7416 jar file executable. The @code{#:test-include} parameter can be used to
7417 specify the list of junit tests to run. It defaults to
7418 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7419 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7420 because abstract classes cannot be run as tests.
7422 The parameter @code{#:build-target} can be used to specify the Ant task
7423 that should be run during the @code{build} phase. By default the
7424 ``jar'' task will be run.
7428 @defvr {Scheme Variable} android-ndk-build-system
7429 @cindex Android distribution
7430 @cindex Android NDK build system
7431 This variable is exported by @code{(guix build-system android-ndk)}. It
7432 implements a build procedure for Android NDK (native development kit)
7433 packages using a Guix-specific build process.
7435 The build system assumes that packages install their public interface
7436 (header) files to the subdirectory @file{include} of the @code{out} output and
7437 their libraries to the subdirectory @file{lib} the @code{out} output.
7439 It's also assumed that the union of all the dependencies of a package
7440 has no conflicting files.
7442 For the time being, cross-compilation is not supported - so right now
7443 the libraries and header files are assumed to be host tools.
7447 @defvr {Scheme Variable} asdf-build-system/source
7448 @defvrx {Scheme Variable} asdf-build-system/sbcl
7449 @defvrx {Scheme Variable} asdf-build-system/ecl
7451 These variables, exported by @code{(guix build-system asdf)}, implement
7452 build procedures for Common Lisp packages using
7453 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7454 definition facility for Common Lisp programs and libraries.
7456 The @code{asdf-build-system/source} system installs the packages in
7457 source form, and can be loaded using any common lisp implementation, via
7458 ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
7459 systems in the format which a particular implementation understands.
7460 These build systems can also be used to produce executable programs, or
7461 lisp images which contain a set of packages pre-loaded.
7463 The build system uses naming conventions. For binary packages, the
7464 package name should be prefixed with the lisp implementation, such as
7465 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7467 Additionally, the corresponding source package should be labeled using
7468 the same convention as python packages (see @ref{Python Modules}), using
7469 the @code{cl-} prefix.
7471 In order to create executable programs and images, the build-side
7472 procedures @code{build-program} and @code{build-image} can be used.
7473 They should be called in a build phase after the
7474 @code{create-asdf-configuration} phase, so that the system which was
7475 just built can be used within the resulting image. @code{build-program}
7476 requires a list of Common Lisp expressions to be passed as the
7477 @code{#:entry-program} argument.
7479 By default, all the @file{.asd} files present in the sources are read to
7480 find system definitions. The @code{#:asd-files} parameter can be used
7481 to specify the list of @file{.asd} files to read. Furthermore, if the
7482 package defines a system for its tests in a separate file, it will be
7483 loaded before the tests are run if it is specified by the
7484 @code{#:test-asd-file} parameter. If it is not set, the files
7485 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7486 and @code{test.asd} will be tried if they exist.
7488 If for some reason the package must be named in a different way than the
7489 naming conventions suggest, or if several systems must be compiled, the
7490 @code{#:asd-systems} parameter can be used to specify the list of system
7495 @defvr {Scheme Variable} cargo-build-system
7496 @cindex Rust programming language
7497 @cindex Cargo (Rust build system)
7498 This variable is exported by @code{(guix build-system cargo)}. It
7499 supports builds of packages using Cargo, the build tool of the
7500 @uref{https://www.rust-lang.org, Rust programming language}.
7502 It adds @code{rustc} and @code{cargo} to the set of inputs.
7503 A different Rust package can be specified with the @code{#:rust} parameter.
7505 Regular cargo dependencies should be added to the package definition similarly
7506 to other packages; those needed only at build time to native-inputs, others to
7507 inputs. If you need to add source-only crates then you should add them to via
7508 the @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7509 spec can be a package or a source definition. Note that the spec must
7510 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7511 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7512 should be added to the package definition via the
7513 @code{#:cargo-development-inputs} parameter.
7515 In its @code{configure} phase, this build system will make any source inputs
7516 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7517 parameters available to cargo. It will also remove an included
7518 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7519 @code{build} phase. The @code{package} phase will run @code{cargo package}
7520 to create a source crate for future use. The @code{install} phase installs
7521 the binaries defined by the crate. Unless @code{install-source? #f} is
7522 defined it will also install a source crate repository of itself and unpacked
7523 sources, to ease in future hacking on rust packages.
7526 @defvr {Scheme Variable} chicken-build-system
7527 This variable is exported by @code{(guix build-system chicken)}. It
7528 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
7529 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
7530 gets compiled by a C compiler, in this case GCC.
7532 This build system adds @code{chicken} to the package inputs, as well as
7533 the packages of @code{gnu-build-system}.
7535 The build system can't (yet) deduce the egg's name automatically, so just like
7536 with @code{go-build-system} and its @code{#:import-path}, you should define
7537 @code{#:egg-name} in the package's @code{arguments} field.
7539 For example, if you are packaging the @code{srfi-1} egg:
7542 (arguments '(#:egg-name "srfi-1"))
7545 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
7546 because CHICKEN doesn't embed absolute references in compiled eggs.
7547 Test dependencies should go to @code{native-inputs}, as usual.
7550 @defvr {Scheme Variable} copy-build-system
7551 This variable is exported by @code{(guix build-system copy)}. It
7552 supports builds of simple packages that don't require much compiling,
7553 mostly just moving files around.
7555 It adds much of the @code{gnu-build-system} packages to the set of
7556 inputs. Because of this, the @code{copy-build-system} does not require
7557 all the boilerplate code often needed for the
7558 @code{trivial-build-system}.
7560 To further simplify the file installation process, an
7561 @code{#:install-plan} argument is exposed to let the packager specify
7562 which files go where. The install plan is a list of @code{(@var{source}
7563 @var{target} [@var{filters}])}. @var{filters} are optional.
7566 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7568 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7569 @item Otherwise install @var{source} as @var{target}.
7572 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7573 the trailing slash of @var{target} is implied with the same meaning
7576 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7577 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7578 @code{#:exclude-regexp}, only select files are installed depending on
7579 the filters. Each filters is specified by a list of strings.
7581 @item With @code{#:include}, install all the files which the path suffix matches
7582 at least one of the elements in the given list.
7583 @item With @code{#:include-regexp}, install all the files which the
7584 subpaths match at least one of the regular expressions in the given
7586 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7587 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7588 install all files but those matching the exclusion filters.
7589 If both inclusions and exclusions are specified, the exclusions are done
7590 on top of the inclusions.
7593 In all cases, the paths relative to @var{source} are preserved within
7600 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7601 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7602 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7603 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7604 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7605 @file{share/my-app/sub/file}.
7606 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7607 @file{share/my-app/file}.
7612 @cindex Clojure (programming language)
7613 @cindex simple Clojure build system
7614 @defvr {Scheme Variable} clojure-build-system
7615 This variable is exported by @code{(guix build-system clojure)}. It implements
7616 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7617 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7620 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7621 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7622 @code{#:zip} parameters, respectively.
7624 A list of source directories, test directories and jar names can be specified
7625 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7626 parameters, respectively. Compile directory and main class can be specified
7627 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7628 Other parameters are documented below.
7630 This build system is an extension of @code{ant-build-system}, but with the
7631 following phases changed:
7636 This phase calls @code{compile} in Clojure to compile source files and runs
7637 @command{jar} to create jars from both source files and compiled files
7638 according to the include list and exclude list specified in
7639 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7640 has priority over the include list. These lists consist of symbols
7641 representing Clojure libraries or the special keyword @code{#:all} representing
7642 all Clojure libraries found under the source directories. The parameter
7643 @code{#:omit-source?} decides if source should be included into the jars.
7646 This phase runs tests according to the include list and exclude list specified
7647 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7648 meanings are analogous to that of @code{#:aot-include} and
7649 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7650 stands for all Clojure libraries found under the test directories. The
7651 parameter @code{#:tests?} decides if tests should be run.
7654 This phase installs all jars built previously.
7657 Apart from the above, this build system also contains an additional phase:
7662 This phase installs all top-level files with base name matching
7663 @code{%doc-regex}. A different regex can be specified with the
7664 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7665 directories specified in @code{#:doc-dirs} are installed as well.
7669 @defvr {Scheme Variable} cmake-build-system
7670 This variable is exported by @code{(guix build-system cmake)}. It
7671 implements the build procedure for packages using the
7672 @url{https://www.cmake.org, CMake build tool}.
7674 It automatically adds the @code{cmake} package to the set of inputs.
7675 Which package is used can be specified with the @code{#:cmake}
7678 The @code{#:configure-flags} parameter is taken as a list of flags
7679 passed to the @command{cmake} command. The @code{#:build-type}
7680 parameter specifies in abstract terms the flags passed to the compiler;
7681 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7682 debugging information''), which roughly means that code is compiled with
7683 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7686 @defvr {Scheme Variable} dune-build-system
7687 This variable is exported by @code{(guix build-system dune)}. It
7688 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7689 tool for the OCaml programming language. It is implemented as an extension
7690 of the @code{ocaml-build-system} which is described below. As such, the
7691 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7694 It automatically adds the @code{dune} package to the set of inputs.
7695 Which package is used can be specified with the @code{#:dune}
7698 There is no @code{configure} phase because dune packages typically don't
7699 need to be configured. The @code{#:build-flags} parameter is taken as a
7700 list of flags passed to the @code{dune} command during the build.
7702 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7703 command instead of the more recent @code{dune} command while building
7704 a package. Its default value is @code{#f}.
7706 The @code{#:package} parameter can be passed to specify a package name, which
7707 is useful when a package contains multiple packages and you want to build
7708 only one of them. This is equivalent to passing the @code{-p} argument to
7712 @defvr {Scheme Variable} go-build-system
7713 This variable is exported by @code{(guix build-system go)}. It
7714 implements a build procedure for Go packages using the standard
7715 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7716 Go build mechanisms}.
7718 The user is expected to provide a value for the key @code{#:import-path}
7719 and, in some cases, @code{#:unpack-path}. The
7720 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7721 corresponds to the file system path expected by the package's build
7722 scripts and any referring packages, and provides a unique way to
7723 refer to a Go package. It is typically based on a combination of the
7724 package source code's remote URI and file system hierarchy structure. In
7725 some cases, you will need to unpack the package's source code to a
7726 different directory structure than the one indicated by the import path,
7727 and @code{#:unpack-path} should be used in such cases.
7729 Packages that provide Go libraries should install their source code into
7730 the built output. The key @code{#:install-source?}, which defaults to
7731 @code{#t}, controls whether or not the source code is installed. It can
7732 be set to @code{#f} for packages that only provide executable files.
7735 @defvr {Scheme Variable} glib-or-gtk-build-system
7736 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7737 is intended for use with packages making use of GLib or GTK+.
7739 This build system adds the following two phases to the ones defined by
7740 @code{gnu-build-system}:
7743 @item glib-or-gtk-wrap
7744 The phase @code{glib-or-gtk-wrap} ensures that programs in
7745 @file{bin/} are able to find GLib ``schemas'' and
7746 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7747 modules}. This is achieved by wrapping the programs in launch scripts
7748 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7749 environment variables.
7751 It is possible to exclude specific package outputs from that wrapping
7752 process by listing their names in the
7753 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7754 when an output is known not to contain any GLib or GTK+ binaries, and
7755 where wrapping would gratuitously add a dependency of that output on
7758 @item glib-or-gtk-compile-schemas
7759 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7760 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7761 GSettings schemas} of GLib are compiled. Compilation is performed by the
7762 @command{glib-compile-schemas} program. It is provided by the package
7763 @code{glib:bin} which is automatically imported by the build system.
7764 The @code{glib} package providing @command{glib-compile-schemas} can be
7765 specified with the @code{#:glib} parameter.
7768 Both phases are executed after the @code{install} phase.
7771 @defvr {Scheme Variable} guile-build-system
7772 This build system is for Guile packages that consist exclusively of Scheme
7773 code and that are so lean that they don't even have a makefile, let alone a
7774 @file{configure} script. It compiles Scheme code using @command{guild
7775 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7776 installs the @file{.scm} and @file{.go} files in the right place. It also
7777 installs documentation.
7779 This build system supports cross-compilation by using the
7780 @option{--target} option of @samp{guild compile}.
7782 Packages built with @code{guile-build-system} must provide a Guile package in
7783 their @code{native-inputs} field.
7786 @defvr {Scheme Variable} julia-build-system
7787 This variable is exported by @code{(guix build-system julia)}. It
7788 implements the build procedure used by @uref{https://julialang.org/,
7789 julia} packages, which essentially is similar to running @samp{julia -e
7790 'using Pkg; Pkg.add(package)'} in an environment where
7791 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7792 Tests are run by calling @code{/test/runtests.jl}.
7794 The Julia package name is read from the file @file{Project.toml}. This
7795 value can be overridden by passing the argument @code{#:julia-package-name}
7796 (which must be correctly capitalized).
7798 Julia packages usually manage their binary dependencies via
7799 @code{JLLWrappers.jl}, a Julia package that creates a module (named
7800 after the wrapped library followed by @code{_jll.jl}.
7802 To add the binary path @code{_jll.jl} packages, you need to patch the
7803 files under @file{src/wrappers/}, replacing the call to the macro
7804 @code{JLLWrappers.@@generate_wrapper_header}, adding as a second
7805 argument containing the store path the binary.
7807 As an example, in the MbedTLS Julia package, we add a build phase
7808 (@pxref{Build Phases}) to insert the absolute file name of the wrapped
7812 (add-after 'unpack 'override-binary-path
7813 (lambda* (#:key inputs #:allow-other-keys)
7814 (for-each (lambda (wrapper)
7815 (substitute* wrapper
7816 (("generate_wrapper_header.*")
7818 "generate_wrapper_header(\"MbedTLS\", \""
7819 (assoc-ref inputs "mbedtls-apache") "\")\n"))))
7820 ;; There's a Julia file for each platform, override them all.
7821 (find-files "src/wrappers/" "\\.jl$"))))
7824 Some older packages that aren't using @file{Package.toml} yet, will require
7825 this file to be created, too. The function @code{julia-create-package-toml}
7826 helps creating the file. You need to pass the outputs and the source of the
7827 package, its name (the same as the @code{file-name} parameter), the package
7828 uuid, the package version, and a list of dependencies specified by their name
7832 @defvr {Scheme Variable} maven-build-system
7833 This variable is exported by @code{(guix build-system maven)}. It implements
7834 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7835 is a dependency and lifecycle management tool for Java. A user of Maven
7836 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7837 When Maven does not have one of the dependencies or plugins in its repository,
7838 it will download them and use them to build the package.
7840 The maven build system ensures that maven will not try to download any
7841 dependency by running in offline mode. Maven will fail if a dependency is
7842 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7843 modified to specify the version of dependencies and plugins that match the
7844 versions available in the guix build environment. Dependencies and plugins
7845 must be installed in the fake maven repository at @file{lib/m2}, and are
7846 symlinked into a proper repository before maven is run. Maven is instructed
7847 to use that repository for the build and installs built artifacts there.
7848 Changed files are copied to the @file{lib/m2} directory of the package output.
7850 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7851 or let the build system use the default @file{pom.xml} file in the sources.
7853 In case you need to specify a dependency's version manually, you can use the
7854 @code{#:local-packages} argument. It takes an association list where the key
7855 is the groupId of the package and its value is an association list where the
7856 key is the artifactId of the package and its value is the version you want to
7857 override in the @file{pom.xml}.
7859 Some packages use dependencies or plugins that are not useful at runtime nor
7860 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7861 using the @code{#:exclude} argument. Its value is an association list where
7862 the key is the groupId of the plugin or dependency you want to remove, and
7863 the value is a list of artifactId you want to remove.
7865 You can override the default @code{jdk} and @code{maven} packages with the
7866 corresponding argument, @code{#:jdk} and @code{#:maven}.
7868 The @code{#:maven-plugins} argument is a list of maven plugins used during
7869 the build, with the same format as the @code{inputs} fields of the package
7870 declaration. Its default value is @code{(default-maven-plugins)} which is
7874 @defvr {Scheme Variable} minify-build-system
7875 This variable is exported by @code{(guix build-system minify)}. It
7876 implements a minification procedure for simple JavaScript packages.
7878 It adds @code{uglify-js} to the set of inputs and uses it to compress
7879 all JavaScript files in the @file{src} directory. A different minifier
7880 package can be specified with the @code{#:uglify-js} parameter, but it
7881 is expected that the package writes the minified code to the standard
7884 When the input JavaScript files are not all located in the @file{src}
7885 directory, the parameter @code{#:javascript-files} can be used to
7886 specify a list of file names to feed to the minifier.
7889 @defvr {Scheme Variable} ocaml-build-system
7890 This variable is exported by @code{(guix build-system ocaml)}. It implements
7891 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7892 of choosing the correct set of commands to run for each package. OCaml
7893 packages can expect many different commands to be run. This build system will
7896 When the package has a @file{setup.ml} file present at the top-level, it will
7897 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7898 @code{ocaml setup.ml -install}. The build system will assume that this file
7899 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7900 care of setting the prefix and enabling tests if they are not disabled. You
7901 can pass configure and build flags with the @code{#:configure-flags} and
7902 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7903 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7904 bypass this system in the build and install phases.
7906 When the package has a @file{configure} file, it is assumed that it is a
7907 hand-made configure script that requires a different argument format than
7908 in the @code{gnu-build-system}. You can add more flags with the
7909 @code{#:configure-flags} key.
7911 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7912 @code{#t}), it will be used and more flags can be passed to the build and
7913 install phases with the @code{#:make-flags} key.
7915 Finally, some packages do not have these files and use a somewhat standard
7916 location for its build system. In that case, the build system will run
7917 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7918 providing the path to the required findlib module. Additional flags can
7919 be passed via the @code{#:build-flags} key. Install is taken care of by
7920 @command{opam-installer}. In this case, the @code{opam} package must
7921 be added to the @code{native-inputs} field of the package definition.
7923 Note that most OCaml packages assume they will be installed in the same
7924 directory as OCaml, which is not what we want in guix. In particular, they
7925 will install @file{.so} files in their module's directory, which is usually
7926 fine because it is in the OCaml compiler directory. In guix though, these
7927 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7928 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7929 @file{.so} libraries should be installed.
7932 @defvr {Scheme Variable} python-build-system
7933 This variable is exported by @code{(guix build-system python)}. It
7934 implements the more or less standard build procedure used by Python
7935 packages, which consists in running @code{python setup.py build} and
7936 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7938 For packages that install stand-alone Python programs under @code{bin/},
7939 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7940 environment variable points to all the Python libraries they depend on.
7942 Which Python package is used to perform the build can be specified with
7943 the @code{#:python} parameter. This is a useful way to force a package
7944 to be built for a specific version of the Python interpreter, which
7945 might be necessary if the package is only compatible with a single
7946 interpreter version.
7948 By default guix calls @code{setup.py} under control of
7949 @code{setuptools}, much like @command{pip} does. Some packages are not
7950 compatible with setuptools (and pip), thus you can disable this by
7951 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7954 @defvr {Scheme Variable} perl-build-system
7955 This variable is exported by @code{(guix build-system perl)}. It
7956 implements the standard build procedure for Perl packages, which either
7957 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7958 followed by @code{Build} and @code{Build install}; or in running
7959 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7960 @code{make} and @code{make install}, depending on which of
7961 @code{Build.PL} or @code{Makefile.PL} is present in the package
7962 distribution. Preference is given to the former if both @code{Build.PL}
7963 and @code{Makefile.PL} exist in the package distribution. This
7964 preference can be reversed by specifying @code{#t} for the
7965 @code{#:make-maker?} parameter.
7967 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7968 passes flags specified by the @code{#:make-maker-flags} or
7969 @code{#:module-build-flags} parameter, respectively.
7971 Which Perl package is used can be specified with @code{#:perl}.
7974 @defvr {Scheme Variable} renpy-build-system
7975 This variable is exported by @code{(guix build-system renpy)}. It implements
7976 the more or less standard build procedure used by Ren'py games, which consists
7977 of loading @code{#:game} once, thereby creating bytecode for it.
7979 It further creates a wrapper script in @code{bin/} and a desktop entry in
7980 @code{share/applications}, both of which can be used to launch the game.
7982 Which Ren'py package is used can be specified with @code{#:renpy}.
7983 Games can also be installed in outputs other than ``out'' by using
7987 @defvr {Scheme Variable} qt-build-system
7988 This variable is exported by @code{(guix build-system qt)}. It
7989 is intended for use with applications using Qt or KDE.
7991 This build system adds the following two phases to the ones defined by
7992 @code{cmake-build-system}:
7996 The phase @code{check-setup} prepares the environment for running
7997 the checks as commonly used by Qt test programs.
7998 For now this only sets some environment variables:
7999 @code{QT_QPA_PLATFORM=offscreen},
8000 @code{DBUS_FATAL_WARNINGS=0} and
8001 @code{CTEST_OUTPUT_ON_FAILURE=1}.
8003 This phase is added before the @code{check} phase.
8004 It's a separate phase to ease adjusting if necessary.
8007 The phase @code{qt-wrap}
8008 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
8009 and output. In case some path is found, all programs in the output's
8010 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
8011 are wrapped in scripts defining the necessary environment variables.
8013 It is possible to exclude specific package outputs from that wrapping process
8014 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
8015 This is useful when an output is known not to contain any Qt binaries, and
8016 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
8019 This phase is added after the @code{install} phase.
8023 @defvr {Scheme Variable} r-build-system
8024 This variable is exported by @code{(guix build-system r)}. It
8025 implements the build procedure used by @uref{https://r-project.org, R}
8026 packages, which essentially is little more than running @samp{R CMD
8027 INSTALL --library=/gnu/store/@dots{}} in an environment where
8028 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
8029 run after installation using the R function
8030 @code{tools::testInstalledPackage}.
8033 @defvr {Scheme Variable} rakudo-build-system
8034 This variable is exported by @code{(guix build-system rakudo)}. It
8035 implements the build procedure used by @uref{https://rakudo.org/,
8036 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
8037 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
8038 installs the binaries, library files and the resources, as well as wrap
8039 the files under the @code{bin/} directory. Tests can be skipped by
8040 passing @code{#f} to the @code{tests?} parameter.
8042 Which rakudo package is used can be specified with @code{rakudo}.
8043 Which perl6-tap-harness package used for the tests can be specified with
8044 @code{#:prove6} or removed by passing @code{#f} to the
8045 @code{with-prove6?} parameter.
8046 Which perl6-zef package used for tests and installing can be specified
8047 with @code{#:zef} or removed by passing @code{#f} to the
8048 @code{with-zef?} parameter.
8051 @defvr {Scheme Variable} texlive-build-system
8052 This variable is exported by @code{(guix build-system texlive)}. It is
8053 used to build TeX packages in batch mode with a specified engine. The
8054 build system sets the @env{TEXINPUTS} variable to find all TeX source
8055 files in the inputs.
8057 By default it runs @code{luatex} on all files ending on @code{ins}. A
8058 different engine and format can be specified with the
8059 @code{#:tex-format} argument. Different build targets can be specified
8060 with the @code{#:build-targets} argument, which expects a list of file
8061 names. The build system adds only @code{texlive-bin} and
8062 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
8063 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
8064 and @code{#:texlive-latex-base}, respectively.
8066 The @code{#:tex-directory} parameter tells the build system where to
8067 install the built files under the texmf tree.
8070 @defvr {Scheme Variable} ruby-build-system
8071 This variable is exported by @code{(guix build-system ruby)}. It
8072 implements the RubyGems build procedure used by Ruby packages, which
8073 involves running @code{gem build} followed by @code{gem install}.
8075 The @code{source} field of a package that uses this build system
8076 typically references a gem archive, since this is the format that Ruby
8077 developers use when releasing their software. The build system unpacks
8078 the gem archive, potentially patches the source, runs the test suite,
8079 repackages the gem, and installs it. Additionally, directories and
8080 tarballs may be referenced to allow building unreleased gems from Git or
8081 a traditional source release tarball.
8083 Which Ruby package is used can be specified with the @code{#:ruby}
8084 parameter. A list of additional flags to be passed to the @command{gem}
8085 command can be specified with the @code{#:gem-flags} parameter.
8088 @defvr {Scheme Variable} waf-build-system
8089 This variable is exported by @code{(guix build-system waf)}. It
8090 implements a build procedure around the @code{waf} script. The common
8091 phases---@code{configure}, @code{build}, and @code{install}---are
8092 implemented by passing their names as arguments to the @code{waf}
8095 The @code{waf} script is executed by the Python interpreter. Which
8096 Python package is used to run the script can be specified with the
8097 @code{#:python} parameter.
8100 @defvr {Scheme Variable} scons-build-system
8101 This variable is exported by @code{(guix build-system scons)}. It
8102 implements the build procedure used by the SCons software construction
8103 tool. This build system runs @code{scons} to build the package,
8104 @code{scons test} to run tests, and then @code{scons install} to install
8107 Additional flags to be passed to @code{scons} can be specified with the
8108 @code{#:scons-flags} parameter. The default build and install targets
8109 can be overridden with @code{#:build-targets} and
8110 @code{#:install-targets} respectively. The version of Python used to
8111 run SCons can be specified by selecting the appropriate SCons package
8112 with the @code{#:scons} parameter.
8115 @defvr {Scheme Variable} haskell-build-system
8116 This variable is exported by @code{(guix build-system haskell)}. It
8117 implements the Cabal build procedure used by Haskell packages, which
8118 involves running @code{runhaskell Setup.hs configure
8119 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
8120 Instead of installing the package by running @code{runhaskell Setup.hs
8121 install}, to avoid trying to register libraries in the read-only
8122 compiler store directory, the build system uses @code{runhaskell
8123 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
8124 addition, the build system generates the package documentation by
8125 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
8126 is passed. Optional Haddock parameters can be passed with the help of
8127 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
8128 not found, the build system looks for @code{Setup.lhs} instead.
8130 Which Haskell compiler is used can be specified with the @code{#:haskell}
8131 parameter which defaults to @code{ghc}.
8134 @defvr {Scheme Variable} dub-build-system
8135 This variable is exported by @code{(guix build-system dub)}. It
8136 implements the Dub build procedure used by D packages, which
8137 involves running @code{dub build} and @code{dub run}.
8138 Installation is done by copying the files manually.
8140 Which D compiler is used can be specified with the @code{#:ldc}
8141 parameter which defaults to @code{ldc}.
8144 @anchor{emacs-build-system}
8145 @defvr {Scheme Variable} emacs-build-system
8146 This variable is exported by @code{(guix build-system emacs)}. It
8147 implements an installation procedure similar to the packaging system
8148 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8150 It first creates the @code{@code{package}-autoloads.el} file, then it
8151 byte compiles all Emacs Lisp files. Differently from the Emacs
8152 packaging system, the Info documentation files are moved to the standard
8153 documentation directory and the @file{dir} file is deleted. The Elisp
8154 package files are installed directly under @file{share/emacs/site-lisp}.
8157 @defvr {Scheme Variable} font-build-system
8158 This variable is exported by @code{(guix build-system font)}. It
8159 implements an installation procedure for font packages where upstream
8160 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
8161 need to be copied into place. It copies font files to standard
8162 locations in the output directory.
8165 @defvr {Scheme Variable} meson-build-system
8166 This variable is exported by @code{(guix build-system meson)}. It
8167 implements the build procedure for packages that use
8168 @url{https://mesonbuild.com, Meson} as their build system.
8170 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
8171 of inputs, and they can be changed with the parameters @code{#:meson}
8172 and @code{#:ninja} if needed. The default Meson is
8173 @code{meson-for-build}, which is special because it doesn't clear the
8174 @code{RUNPATH} of binaries and libraries when they are installed.
8176 This build system is an extension of @code{gnu-build-system}, but with the
8177 following phases changed to some specific for Meson:
8182 The phase runs @code{meson} with the flags specified in
8183 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
8184 @code{debugoptimized} unless something else is specified in
8185 @code{#:build-type}.
8188 The phase runs @code{ninja} to build the package in parallel by default, but
8189 this can be changed with @code{#:parallel-build?}.
8192 The phase runs @code{ninja} with the target specified in @code{#:test-target},
8193 which is @code{"test"} by default.
8196 The phase runs @code{ninja install} and can not be changed.
8199 Apart from that, the build system also adds the following phases:
8204 This phase ensures that all binaries can find the libraries they need.
8205 It searches for required libraries in subdirectories of the package being
8206 built, and adds those to @code{RUNPATH} where needed. It also removes
8207 references to libraries left over from the build phase by
8208 @code{meson-for-build}, such as test dependencies, that aren't actually
8209 required for the program to run.
8211 @item glib-or-gtk-wrap
8212 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8213 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8215 @item glib-or-gtk-compile-schemas
8216 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8217 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8221 @defvr {Scheme Variable} linux-module-build-system
8222 @code{linux-module-build-system} allows building Linux kernel modules.
8224 @cindex build phases
8225 This build system is an extension of @code{gnu-build-system}, but with the
8226 following phases changed:
8231 This phase configures the environment so that the Linux kernel's Makefile
8232 can be used to build the external kernel module.
8235 This phase uses the Linux kernel's Makefile in order to build the external
8239 This phase uses the Linux kernel's Makefile in order to install the external
8243 It is possible and useful to specify the Linux kernel to use for building
8244 the module (in the @code{arguments} form of a package using the
8245 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
8248 @defvr {Scheme Variable} node-build-system
8249 This variable is exported by @code{(guix build-system node)}. It
8250 implements the build procedure used by @uref{https://nodejs.org,
8251 Node.js}, which implements an approximation of the @code{npm install}
8252 command, followed by an @code{npm test} command.
8254 Which Node.js package is used to interpret the @code{npm} commands can
8255 be specified with the @code{#:node} parameter which defaults to
8259 Lastly, for packages that do not need anything as sophisticated, a
8260 ``trivial'' build system is provided. It is trivial in the sense that
8261 it provides basically no support: it does not pull any implicit inputs,
8262 and does not have a notion of build phases.
8264 @defvr {Scheme Variable} trivial-build-system
8265 This variable is exported by @code{(guix build-system trivial)}.
8267 This build system requires a @code{#:builder} argument. This argument
8268 must be a Scheme expression that builds the package output(s)---as
8269 with @code{build-expression->derivation} (@pxref{Derivations,
8270 @code{build-expression->derivation}}).
8274 @section Build Phases
8276 @cindex build phases, for packages
8277 Almost all package build systems implement a notion @dfn{build phases}:
8278 a sequence of actions that the build system executes, when you build the
8279 package, leading to the installed byproducts in the store. A notable
8280 exception is the ``bare-bones'' @code{trivial-build-system}
8281 (@pxref{Build Systems}).
8283 As discussed in the previous section, those build systems provide a
8284 standard list of phases. For @code{gnu-build-system}, the main build
8285 phases are the following:
8289 Unpack the source tarball, and change the current directory to the
8290 extracted source tree. If the source is actually a directory, copy it
8291 to the build tree, and enter that directory.
8293 @item patch-source-shebangs
8294 Patch shebangs encountered in source files so they refer to the right
8295 store file names. For instance, this changes @code{#!/bin/sh} to
8296 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
8299 Run the @file{configure} script with a number of default options, such
8300 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
8301 by the @code{#:configure-flags} argument.
8304 Run @code{make} with the list of flags specified with
8305 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
8306 (the default), build with @code{make -j}.
8309 Run @code{make check}, or some other target specified with
8310 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
8311 @code{#:parallel-tests?} argument is true (the default), run @code{make
8315 Run @code{make install} with the flags listed in @code{#:make-flags}.
8317 @item patch-shebangs
8318 Patch shebangs on the installed executable files.
8321 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
8322 is false), copying them to the @code{debug} output when available
8323 (@pxref{Installing Debugging Files}).
8326 Other build systems have similar phases, with some variations. For
8327 example, @code{cmake-build-system} has same-named phases but its
8328 @code{configure} phases runs @code{cmake} instead of @code{./configure}.
8329 Others, such as @code{python-build-system}, have a wholly different list
8330 of standard phases. All this code runs on the @dfn{build side}: it is
8331 evaluated when you actually build the package, in a dedicated build
8332 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8334 Build phases are represented as association lists or ``alists''
8335 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8336 each key is a symbol for the name of the phase and the associated value
8337 is a procedure that accepts an arbitrary number of arguments. By
8338 convention, those procedures receive information about the build in the
8339 form of @dfn{keyword parameters}, which they can use or ignore.
8341 @vindex %standard-phases
8342 For example, here is how @code{(guix build gnu-build-system)} defines
8343 @code{%standard-phases}, the variable holding its alist of build
8344 phases@footnote{We present a simplified view of those build phases, but
8345 do take a look at @code{(guix build gnu-build-system)} to see all the
8349 ;; The build phases of 'gnu-build-system'.
8351 (define* (unpack #:key source #:allow-other-keys)
8352 ;; Extract the source tarball.
8353 (invoke "tar" "xvf" source))
8355 (define* (configure #:key outputs #:allow-other-keys)
8356 ;; Run the 'configure' script. Install to output "out".
8357 (let ((out (assoc-ref outputs "out")))
8358 (invoke "./configure"
8359 (string-append "--prefix=" out))))
8361 (define* (build #:allow-other-keys)
8365 (define* (check #:key (test-target "check") (tests? #true)
8367 ;; Run the test suite.
8369 (invoke "make" test-target)
8370 (display "test suite not run\n")))
8372 (define* (install #:allow-other-keys)
8373 ;; Install files to the prefix 'configure' specified.
8374 (invoke "make" "install"))
8376 (define %standard-phases
8377 ;; The list of standard phases (quite a few are omitted
8378 ;; for brevity). Each element is a symbol/procedure pair.
8379 (list (cons 'unpack unpack)
8380 (cons 'configure configure)
8383 (cons 'install install)))
8386 This shows how @code{%standard-phases} is defined as a list of
8387 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8388 Manual}). The first pair associates the @code{unpack} procedure with
8389 the @code{unpack} symbol---a name; the second pair defines the
8390 @code{configure} phase similarly, and so on. When building a package
8391 that uses @code{gnu-build-system} with its default list of phases, those
8392 phases are executed sequentially. You can see the name of each phase
8393 started and completed in the build log of packages that you build.
8395 Let's now look at the procedures themselves. Each one is defined with
8396 @code{define*}: @code{#:key} lists keyword parameters the procedure
8397 accepts, possibly with a default value, and @code{#:allow-other-keys}
8398 specifies that other keyword parameters are ignored (@pxref{Optional
8399 Arguments,,, guile, GNU Guile Reference Manual}).
8401 The @code{unpack} procedure honors the @code{source} parameter, which
8402 the build system uses to pass the file name of the source tarball (or
8403 version control checkout), and it ignores other parameters. The
8404 @code{configure} phase only cares about the @code{outputs} parameter, an
8405 alist mapping package output names to their store file name
8406 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8407 for @code{out}, the default output, and passes it to
8408 @command{./configure} as the installation prefix, meaning that
8409 @command{make install} will eventually copy all the files in that
8410 directory (@pxref{Configuration, configuration and makefile
8411 conventions,, standards, GNU Coding Standards}). @code{build} and
8412 @code{install} ignore all their arguments. @code{check} honors the
8413 @code{test-target} argument, which specifies the name of the Makefile
8414 target to run tests; it prints a message and skips tests when
8415 @code{tests?} is false.
8417 @cindex build phases, customizing
8418 The list of phases used for a particular package can be changed with the
8419 @code{#:phases} parameter of the build system. Changing the set of
8420 build phases boils down to building a new alist of phases based on the
8421 @code{%standard-phases} alist described above. This can be done with
8422 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8423 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8424 more convenient to do so with @code{modify-phases} (@pxref{Build
8425 Utilities, @code{modify-phases}}).
8427 Here is an example of a package definition that removes the
8428 @code{configure} phase of @code{%standard-phases} and inserts a new
8429 phase before the @code{build} phase, called
8430 @code{set-prefix-in-makefile}:
8433 (define-public example
8436 ;; other fields omitted
8437 (build-system gnu-build-system)
8439 '(#:phases (modify-phases %standard-phases
8441 (add-before 'build 'set-prefix-in-makefile
8442 (lambda* (#:key outputs #:allow-other-keys)
8443 ;; Modify the makefile so that its
8444 ;; 'PREFIX' variable points to "out".
8445 (let ((out (assoc-ref outputs "out")))
8446 (substitute* "Makefile"
8448 (string-append "PREFIX = "
8453 The new phase that is inserted is written as an anonymous procedure,
8454 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8455 we have seen before. @xref{Build Utilities}, for more about the helpers
8456 used by this phase, and for more examples of @code{modify-phases}.
8458 @cindex code staging
8459 @cindex staging, of code
8460 Keep in mind that build phases are code evaluated at the time the
8461 package is actually built. This explains why the whole
8462 @code{modify-phases} expression above is quoted (it comes after the
8463 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8464 @xref{G-Expressions}, for an explanation of code staging and the
8465 @dfn{code strata} involved.
8467 @node Build Utilities
8468 @section Build Utilities
8470 As soon as you start writing non-trivial package definitions
8471 (@pxref{Defining Packages}) or other build actions
8472 (@pxref{G-Expressions}), you will likely start looking for helpers for
8473 ``shell-like'' actions---creating directories, copying and deleting
8474 files recursively, manipulating build phases, and so on. The
8475 @code{(guix build utils)} module provides such utility procedures.
8477 Most build systems load @code{(guix build utils)} (@pxref{Build
8478 Systems}). Thus, when writing custom build phases for your package
8479 definitions, you can usually assume those procedures are in scope.
8481 When writing G-expressions, you can import @code{(guix build utils)} on
8482 the ``build side'' using @code{with-imported-modules} and then put it in
8483 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8484 guile, GNU Guile Reference Manual}):
8487 (with-imported-modules '((guix build utils)) ;import it
8488 (computed-file "empty-tree"
8491 (use-modules (guix build utils))
8493 ;; Happily use its 'mkdir-p' procedure.
8494 (mkdir-p (string-append #$output "/a/b/c")))))
8497 The remainder of this section is the reference for most of the utility
8498 procedures provided by @code{(guix build utils)}.
8500 @c TODO Document what's missing.
8502 @subsection Dealing with Store File Names
8504 This section documents procedures that deal with store file names.
8506 @deffn {Scheme Procedure} %store-directory
8507 Return the directory name of the store.
8510 @deffn {Scheme Procedure} store-file-name? @var{file}
8511 Return true if @var{file} is in the store.
8514 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8515 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8516 The result is typically a @code{"@var{package}-@var{version}"} string.
8519 @deffn {Scheme Procedure} package-name->name+version @var{name}
8520 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8521 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8522 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8523 followed by a digit is considered to introduce the version part.
8526 @subsection File Types
8528 The procedures below deal with files and file types.
8530 @deffn {Scheme Procedure} directory-exists? @var{dir}
8531 Return @code{#t} if @var{dir} exists and is a directory.
8534 @deffn {Scheme Procedure} executable-file? @var{file}
8535 Return @code{#t} if @var{file} exists and is executable.
8538 @deffn {Scheme Procedure} symbolic-link? @var{file}
8539 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8542 @deffn {Scheme Procedure} elf-file? @var{file}
8543 @deffnx {Scheme Procedure} ar-file? @var{file}
8544 @deffnx {Scheme Procedure} gzip-file? @var{file}
8545 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8546 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8549 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8550 If @var{file} is a gzip file, reset its embedded timestamp (as with
8551 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8552 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8555 @subsection File Manipulation
8557 The following procedures and macros help create, modify, and delete
8558 files. They provide functionality comparable to common shell utilities
8559 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8560 @command{sed}. They complement Guile's extensive, but low-level, file
8561 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8563 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8564 Run @var{body} with @var{directory} as the process's current directory.
8566 Essentially, this macro changes the current directory to @var{directory}
8567 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8568 guile, GNU Guile Reference Manual}). It changes back to the initial
8569 directory when the dynamic extent of @var{body} is left, be it @i{via}
8570 normal procedure return or @i{via} a non-local exit such as an
8574 @deffn {Scheme Procedure} mkdir-p @var{dir}
8575 Create directory @var{dir} and all its ancestors.
8578 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8579 Create @var{directory} if it does not exist and copy @var{file} in there
8580 under the same name.
8583 @deffn {Scheme Procedure} make-file-writable @var{file}
8584 Make @var{file} writable for its owner.
8587 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8588 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8589 Copy @var{source} directory to @var{destination}. Follow symlinks if
8590 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8591 @var{keep-mtime?} is true, keep the modification time of the files in
8592 @var{source} on those of @var{destination}. Write verbose output to the
8596 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8597 [#:follow-mounts? #f]
8598 Delete @var{dir} recursively, like @command{rm -rf}, without following
8599 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8600 is true. Report but ignore errors.
8603 @deffn {Scheme Syntax} substitute* @var{file} @
8604 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8605 Substitute @var{regexp} in @var{file} by the string returned by
8606 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8607 the corresponding positional regexp sub-expression. For example:
8613 (("foo([a-z]+)bar(.*)$" all letters end)
8614 (string-append "baz" letter end)))
8617 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8618 by @code{good morning}. Anytime a line of @var{file} matches the second
8619 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8620 to the first sub-expression, and @code{end} is bound to the last one.
8622 When one of the @var{match-var} is @code{_}, no variable is bound to the
8623 corresponding match substring.
8625 Alternatively, @var{file} may be a list of file names, in which case
8626 they are all subject to the substitutions.
8628 Be careful about using @code{$} to match the end of a line; by itself it
8629 won't match the terminating newline of a line.
8632 @subsection File Search
8634 @cindex file, searching
8635 This section documents procedures to search and filter files.
8637 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8638 Return a predicate that returns true when passed a file name whose base
8639 name matches @var{regexp}.
8642 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8643 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8644 Return the lexicographically sorted list of files under @var{dir} for
8645 which @var{pred} returns true. @var{pred} is passed two arguments: the
8646 absolute file name, and its stat buffer; the default predicate always
8647 returns true. @var{pred} can also be a regular expression, in which
8648 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8649 @var{stat} is used to obtain file information; using @code{lstat} means
8650 that symlinks are not followed. If @var{directories?} is true, then
8651 directories will also be included. If @var{fail-on-error?} is true,
8652 raise an exception upon error.
8655 Here are a few examples where we assume that the current directory is
8656 the root of the Guix source tree:
8659 ;; List all the regular files in the current directory.
8661 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8663 ;; List all the .scm files under gnu/services.
8664 (find-files "gnu/services" "\\.scm$")
8665 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8667 ;; List ar files in the current directory.
8668 (find-files "." (lambda (file stat) (ar-file? file)))
8669 @result{} ("./libformat.a" "./libstore.a" @dots{})
8672 @deffn {Scheme Procedure} which @var{program}
8673 Return the complete file name for @var{program} as found in
8674 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8677 @subsection Build Phases
8679 @cindex build phases
8680 The @code{(guix build utils)} also contains tools to manipulate build
8681 phases as used by build systems (@pxref{Build Systems}). Build phases
8682 are represented as association lists or ``alists'' (@pxref{Association
8683 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8684 naming the phase and the associated value is a procedure (@pxref{Build
8687 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8688 manipulate alists. The @code{(guix build utils)} module complements
8689 those with tools written with build phases in mind.
8691 @cindex build phases, modifying
8692 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8693 Modify @var{phases} sequentially as per each @var{clause}, which may
8694 have one of the following forms:
8697 (delete @var{old-phase-name})
8698 (replace @var{old-phase-name} @var{new-phase})
8699 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8700 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8703 Where every @var{phase-name} above is an expression evaluating to a
8704 symbol, and @var{new-phase} an expression evaluating to a procedure.
8707 The example below is taken from the definition of the @code{grep}
8708 package. It adds a phase to run after the @code{install} phase, called
8709 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8710 is for anonymous procedures) that takes a @code{#:outputs} keyword
8711 argument and ignores extra keyword arguments (@pxref{Optional
8712 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8713 @code{lambda*} and optional and keyword arguments.) The phase uses
8714 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8715 scripts so that they refer to @code{grep} by its absolute file name:
8718 (modify-phases %standard-phases
8719 (add-after 'install 'fix-egrep-and-fgrep
8720 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8721 ;; absolute file name instead of searching for it in $PATH.
8722 (lambda* (#:key outputs #:allow-other-keys)
8723 (let* ((out (assoc-ref outputs "out"))
8724 (bin (string-append out "/bin")))
8725 (substitute* (list (string-append bin "/egrep")
8726 (string-append bin "/fgrep"))
8728 (string-append "exec " bin "/grep")))
8732 In the example below, phases are modified in two ways: the standard
8733 @code{configure} phase is deleted, presumably because the package does
8734 not have a @file{configure} script or anything similar, and the default
8735 @code{install} phase is replaced by one that manually copies the
8736 executable files to be installed:
8739 (modify-phases %standard-phases
8740 (delete 'configure) ;no 'configure' script
8742 (lambda* (#:key outputs #:allow-other-keys)
8743 ;; The package's Makefile doesn't provide an "install"
8744 ;; rule so do it by ourselves.
8745 (let ((bin (string-append (assoc-ref outputs "out")
8747 (install-file "footswitch" bin)
8748 (install-file "scythe" bin)
8752 @c TODO: Add more examples.
8761 Conceptually, the @dfn{store} is the place where derivations that have
8762 been built successfully are stored---by default, @file{/gnu/store}.
8763 Sub-directories in the store are referred to as @dfn{store items} or
8764 sometimes @dfn{store paths}. The store has an associated database that
8765 contains information such as the store paths referred to by each store
8766 path, and the list of @emph{valid} store items---results of successful
8767 builds. This database resides in @file{@var{localstatedir}/guix/db},
8768 where @var{localstatedir} is the state directory specified @i{via}
8769 @option{--localstatedir} at configure time, usually @file{/var}.
8771 The store is @emph{always} accessed by the daemon on behalf of its clients
8772 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8773 connect to the daemon over a Unix-domain socket, send requests to it,
8774 and read the result---these are remote procedure calls, or RPCs.
8777 Users must @emph{never} modify files under @file{/gnu/store} directly.
8778 This would lead to inconsistencies and break the immutability
8779 assumptions of Guix's functional model (@pxref{Introduction}).
8781 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8782 how to check the integrity of the store and attempt recovery from
8783 accidental modifications.
8786 The @code{(guix store)} module provides procedures to connect to the
8787 daemon, and to perform RPCs. These are described below. By default,
8788 @code{open-connection}, and thus all the @command{guix} commands,
8789 connect to the local daemon or to the URI specified by the
8790 @env{GUIX_DAEMON_SOCKET} environment variable.
8792 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8793 When set, the value of this variable should be a file name or a URI
8794 designating the daemon endpoint. When it is a file name, it denotes a
8795 Unix-domain socket to connect to. In addition to file names, the
8796 supported URI schemes are:
8801 These are for Unix-domain sockets.
8802 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8803 @file{/var/guix/daemon-socket/socket}.
8806 @cindex daemon, remote access
8807 @cindex remote access to the daemon
8808 @cindex daemon, cluster setup
8809 @cindex clusters, daemon setup
8810 These URIs denote connections over TCP/IP, without encryption nor
8811 authentication of the remote host. The URI must specify the host name
8812 and optionally a port number (by default port 44146 is used):
8815 guix://master.guix.example.org:1234
8818 This setup is suitable on local networks, such as clusters, where only
8819 trusted nodes may connect to the build daemon at
8820 @code{master.guix.example.org}.
8822 The @option{--listen} option of @command{guix-daemon} can be used to
8823 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8824 @option{--listen}}).
8827 @cindex SSH access to build daemons
8828 These URIs allow you to connect to a remote daemon over SSH@. This
8829 feature requires Guile-SSH (@pxref{Requirements}) and a working
8830 @command{guile} binary in @env{PATH} on the destination machine. It
8831 supports public key and GSSAPI authentication. A typical URL might look
8835 ssh://charlie@@guix.example.org:22
8838 As for @command{guix copy}, the usual OpenSSH client configuration files
8839 are honored (@pxref{Invoking guix copy}).
8842 Additional URI schemes may be supported in the future.
8844 @c XXX: Remove this note when the protocol incurs fewer round trips
8845 @c and when (guix derivations) no longer relies on file system access.
8847 The ability to connect to remote build daemons is considered
8848 experimental as of @value{VERSION}. Please get in touch with us to
8849 share any problems or suggestions you may have (@pxref{Contributing}).
8853 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8854 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8855 @var{reserve-space?} is true, instruct it to reserve a little bit of
8856 extra space on the file system so that the garbage collector can still
8857 operate should the disk become full. Return a server object.
8859 @var{file} defaults to @code{%default-socket-path}, which is the normal
8860 location given the options that were passed to @command{configure}.
8863 @deffn {Scheme Procedure} close-connection @var{server}
8864 Close the connection to @var{server}.
8867 @defvr {Scheme Variable} current-build-output-port
8868 This variable is bound to a SRFI-39 parameter, which refers to the port
8869 where build and error logs sent by the daemon should be written.
8872 Procedures that make RPCs all take a server object as their first
8875 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8876 @cindex invalid store items
8877 Return @code{#t} when @var{path} designates a valid store item and
8878 @code{#f} otherwise (an invalid item may exist on disk but still be
8879 invalid, for instance because it is the result of an aborted or failed
8882 A @code{&store-protocol-error} condition is raised if @var{path} is not
8883 prefixed by the store directory (@file{/gnu/store}).
8886 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8887 Add @var{text} under file @var{name} in the store, and return its store
8888 path. @var{references} is the list of store paths referred to by the
8889 resulting store path.
8892 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8894 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8895 file names, or derivation/output pairs, using the specified
8896 @var{mode}---@code{(build-mode normal)} by default.
8899 Note that the @code{(guix monads)} module provides a monad as well as
8900 monadic versions of the above procedures, with the goal of making it
8901 more convenient to work with code that accesses the store (@pxref{The
8905 @i{This section is currently incomplete.}
8908 @section Derivations
8911 Low-level build actions and the environment in which they are performed
8912 are represented by @dfn{derivations}. A derivation contains the
8913 following pieces of information:
8917 The outputs of the derivation---derivations produce at least one file or
8918 directory in the store, but may produce more.
8921 @cindex build-time dependencies
8922 @cindex dependencies, build-time
8923 The inputs of the derivations---i.e., its build-time dependencies---which may
8924 be other derivations or plain files in the store (patches, build scripts,
8928 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8931 The file name of a build script in the store, along with the arguments
8935 A list of environment variables to be defined.
8939 @cindex derivation path
8940 Derivations allow clients of the daemon to communicate build actions to
8941 the store. They exist in two forms: as an in-memory representation,
8942 both on the client- and daemon-side, and as files in the store whose
8943 name end in @file{.drv}---these files are referred to as @dfn{derivation
8944 paths}. Derivations paths can be passed to the @code{build-derivations}
8945 procedure to perform the build actions they prescribe (@pxref{The
8948 @cindex fixed-output derivations
8949 Operations such as file downloads and version-control checkouts for
8950 which the expected content hash is known in advance are modeled as
8951 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8952 of a fixed-output derivation are independent of its inputs---e.g., a
8953 source code download produces the same result regardless of the download
8954 method and tools being used.
8957 @cindex run-time dependencies
8958 @cindex dependencies, run-time
8959 The outputs of derivations---i.e., the build results---have a set of
8960 @dfn{references}, as reported by the @code{references} RPC or the
8961 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8962 are the set of run-time dependencies of the build results. References are a
8963 subset of the inputs of the derivation; this subset is automatically computed
8964 by the build daemon by scanning all the files in the outputs.
8966 The @code{(guix derivations)} module provides a representation of
8967 derivations as Scheme objects, along with procedures to create and
8968 otherwise manipulate derivations. The lowest-level primitive to create
8969 a derivation is the @code{derivation} procedure:
8971 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8972 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8973 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8974 [#:system (%current-system)] [#:references-graphs #f] @
8975 [#:allowed-references #f] [#:disallowed-references #f] @
8976 [#:leaked-env-vars #f] [#:local-build? #f] @
8977 [#:substitutable? #t] [#:properties '()]
8978 Build a derivation with the given arguments, and return the resulting
8979 @code{<derivation>} object.
8981 When @var{hash} and @var{hash-algo} are given, a
8982 @dfn{fixed-output derivation} is created---i.e., one whose result is
8983 known in advance, such as a file download. If, in addition,
8984 @var{recursive?} is true, then that fixed output may be an executable
8985 file or a directory and @var{hash} must be the hash of an archive
8986 containing this output.
8988 When @var{references-graphs} is true, it must be a list of file
8989 name/store path pairs. In that case, the reference graph of each store
8990 path is exported in the build environment in the corresponding file, in
8991 a simple text format.
8993 When @var{allowed-references} is true, it must be a list of store items
8994 or outputs that the derivation's output may refer to. Likewise,
8995 @var{disallowed-references}, if true, must be a list of things the
8996 outputs may @emph{not} refer to.
8998 When @var{leaked-env-vars} is true, it must be a list of strings
8999 denoting environment variables that are allowed to ``leak'' from the
9000 daemon's environment to the build environment. This is only applicable
9001 to fixed-output derivations---i.e., when @var{hash} is true. The main
9002 use is to allow variables such as @code{http_proxy} to be passed to
9003 derivations that download files.
9005 When @var{local-build?} is true, declare that the derivation is not a
9006 good candidate for offloading and should rather be built locally
9007 (@pxref{Daemon Offload Setup}). This is the case for small derivations
9008 where the costs of data transfers would outweigh the benefits.
9010 When @var{substitutable?} is false, declare that substitutes of the
9011 derivation's output should not be used (@pxref{Substitutes}). This is
9012 useful, for instance, when building packages that capture details of the
9013 host CPU instruction set.
9015 @var{properties} must be an association list describing ``properties'' of the
9016 derivation. It is kept as-is, uninterpreted, in the derivation.
9020 Here's an example with a shell script as its builder, assuming
9021 @var{store} is an open connection to the daemon, and @var{bash} points
9022 to a Bash executable in the store:
9025 (use-modules (guix utils)
9029 (let ((builder ; add the Bash script to the store
9030 (add-text-to-store store "my-builder.sh"
9031 "echo hello world > $out\n" '())))
9032 (derivation store "foo"
9033 bash `("-e" ,builder)
9034 #:inputs `((,bash) (,builder))
9035 #:env-vars '(("HOME" . "/homeless"))))
9036 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
9039 As can be guessed, this primitive is cumbersome to use directly. A
9040 better approach is to write build scripts in Scheme, of course! The
9041 best course of action for that is to write the build code as a
9042 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
9043 information, @pxref{G-Expressions}.
9045 Once upon a time, @code{gexp->derivation} did not exist and constructing
9046 derivations with build code written in Scheme was achieved with
9047 @code{build-expression->derivation}, documented below. This procedure
9048 is now deprecated in favor of the much nicer @code{gexp->derivation}.
9050 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
9051 @var{name} @var{exp} @
9052 [#:system (%current-system)] [#:inputs '()] @
9053 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
9054 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9055 [#:references-graphs #f] [#:allowed-references #f] @
9056 [#:disallowed-references #f] @
9057 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
9058 Return a derivation that executes Scheme expression @var{exp} as a
9059 builder for derivation @var{name}. @var{inputs} must be a list of
9060 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
9061 @code{"out"} is assumed. @var{modules} is a list of names of Guile
9062 modules from the current search path to be copied in the store,
9063 compiled, and made available in the load path during the execution of
9064 @var{exp}---e.g., @code{((guix build utils) (guix build
9065 gnu-build-system))}.
9067 @var{exp} is evaluated in an environment where @code{%outputs} is bound
9068 to a list of output/path pairs, and where @code{%build-inputs} is bound
9069 to a list of string/output-path pairs made from @var{inputs}.
9070 Optionally, @var{env-vars} is a list of string pairs specifying the name
9071 and value of environment variables visible to the builder. The builder
9072 terminates by passing the result of @var{exp} to @code{exit}; thus, when
9073 @var{exp} returns @code{#f}, the build is considered to have failed.
9075 @var{exp} is built using @var{guile-for-build} (a derivation). When
9076 @var{guile-for-build} is omitted or is @code{#f}, the value of the
9077 @code{%guile-for-build} fluid is used instead.
9079 See the @code{derivation} procedure for the meaning of
9080 @var{references-graphs}, @var{allowed-references},
9081 @var{disallowed-references}, @var{local-build?}, and
9082 @var{substitutable?}.
9086 Here's an example of a single-output derivation that creates a directory
9087 containing one file:
9090 (let ((builder '(let ((out (assoc-ref %outputs "out")))
9091 (mkdir out) ; create /gnu/store/@dots{}-goo
9092 (call-with-output-file (string-append out "/test")
9094 (display '(hello guix) p))))))
9095 (build-expression->derivation store "goo" builder))
9097 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
9101 @node The Store Monad
9102 @section The Store Monad
9106 The procedures that operate on the store described in the previous
9107 sections all take an open connection to the build daemon as their first
9108 argument. Although the underlying model is functional, they either have
9109 side effects or depend on the current state of the store.
9111 The former is inconvenient: the connection to the build daemon has to be
9112 carried around in all those functions, making it impossible to compose
9113 functions that do not take that parameter with functions that do. The
9114 latter can be problematic: since store operations have side effects
9115 and/or depend on external state, they have to be properly sequenced.
9117 @cindex monadic values
9118 @cindex monadic functions
9119 This is where the @code{(guix monads)} module comes in. This module
9120 provides a framework for working with @dfn{monads}, and a particularly
9121 useful monad for our uses, the @dfn{store monad}. Monads are a
9122 construct that allows two things: associating ``context'' with values
9123 (in our case, the context is the store), and building sequences of
9124 computations (here computations include accesses to the store). Values
9125 in a monad---values that carry this additional context---are called
9126 @dfn{monadic values}; procedures that return such values are called
9127 @dfn{monadic procedures}.
9129 Consider this ``normal'' procedure:
9132 (define (sh-symlink store)
9133 ;; Return a derivation that symlinks the 'bash' executable.
9134 (let* ((drv (package-derivation store bash))
9135 (out (derivation->output-path drv))
9136 (sh (string-append out "/bin/bash")))
9137 (build-expression->derivation store "sh"
9138 `(symlink ,sh %output))))
9141 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
9142 as a monadic function:
9145 (define (sh-symlink)
9146 ;; Same, but return a monadic value.
9147 (mlet %store-monad ((drv (package->derivation bash)))
9148 (gexp->derivation "sh"
9149 #~(symlink (string-append #$drv "/bin/bash")
9153 There are several things to note in the second version: the @code{store}
9154 parameter is now implicit and is ``threaded'' in the calls to the
9155 @code{package->derivation} and @code{gexp->derivation} monadic
9156 procedures, and the monadic value returned by @code{package->derivation}
9157 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
9159 As it turns out, the call to @code{package->derivation} can even be
9160 omitted since it will take place implicitly, as we will see later
9161 (@pxref{G-Expressions}):
9164 (define (sh-symlink)
9165 (gexp->derivation "sh"
9166 #~(symlink (string-append #$bash "/bin/bash")
9171 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
9172 @c for the funny quote.
9173 Calling the monadic @code{sh-symlink} has no effect. As someone once
9174 said, ``you exit a monad like you exit a building on fire: by running''.
9175 So, to exit the monad and get the desired effect, one must use
9176 @code{run-with-store}:
9179 (run-with-store (open-connection) (sh-symlink))
9180 @result{} /gnu/store/...-sh-symlink
9183 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
9184 new ``meta-commands'' to make it easier to deal with monadic procedures:
9185 @code{run-in-store}, and @code{enter-store-monad}. The former is used
9186 to ``run'' a single monadic value through the store:
9189 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
9190 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9193 The latter enters a recursive REPL, where all the return values are
9194 automatically run through the store:
9197 scheme@@(guile-user)> ,enter-store-monad
9198 store-monad@@(guile-user) [1]> (package->derivation hello)
9199 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9200 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
9201 $3 = "/gnu/store/@dots{}-foo"
9202 store-monad@@(guile-user) [1]> ,q
9203 scheme@@(guile-user)>
9207 Note that non-monadic values cannot be returned in the
9208 @code{store-monad} REPL.
9210 The main syntactic forms to deal with monads in general are provided by
9211 the @code{(guix monads)} module and are described below.
9213 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
9214 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
9218 @deffn {Scheme Syntax} return @var{val}
9219 Return a monadic value that encapsulates @var{val}.
9222 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
9223 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
9224 procedures @var{mproc}@dots{}@footnote{This operation is commonly
9225 referred to as ``bind'', but that name denotes an unrelated procedure in
9226 Guile. Thus we use this somewhat cryptic symbol inherited from the
9227 Haskell language.}. There can be one @var{mproc} or several of them, as
9232 (with-monad %state-monad
9234 (lambda (x) (return (+ 1 x)))
9235 (lambda (x) (return (* 2 x)))))
9239 @result{} some-state
9243 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
9245 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
9247 Bind the variables @var{var} to the monadic values @var{mval} in
9248 @var{body}, which is a sequence of expressions. As with the bind
9249 operator, this can be thought of as ``unpacking'' the raw, non-monadic
9250 value ``contained'' in @var{mval} and making @var{var} refer to that
9251 raw, non-monadic value within the scope of the @var{body}. The form
9252 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
9253 @var{val}, as per @code{let}. The binding operations occur in sequence
9254 from left to right. The last expression of @var{body} must be a monadic
9255 expression, and its result will become the result of the @code{mlet} or
9256 @code{mlet*} when run in the @var{monad}.
9258 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
9259 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
9262 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
9263 Bind @var{mexp} and the following monadic expressions in sequence,
9264 returning the result of the last expression. Every expression in the
9265 sequence must be a monadic expression.
9267 This is akin to @code{mlet}, except that the return values of the
9268 monadic expressions are ignored. In that sense, it is analogous to
9269 @code{begin}, but applied to monadic expressions.
9272 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
9273 When @var{condition} is true, evaluate the sequence of monadic
9274 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9275 @var{condition} is false, return @code{*unspecified*} in the current
9276 monad. Every expression in the sequence must be a monadic expression.
9279 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
9280 When @var{condition} is false, evaluate the sequence of monadic
9281 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9282 @var{condition} is true, return @code{*unspecified*} in the current
9283 monad. Every expression in the sequence must be a monadic expression.
9287 The @code{(guix monads)} module provides the @dfn{state monad}, which
9288 allows an additional value---the state---to be @emph{threaded} through
9289 monadic procedure calls.
9291 @defvr {Scheme Variable} %state-monad
9292 The state monad. Procedures in the state monad can access and change
9293 the state that is threaded.
9295 Consider the example below. The @code{square} procedure returns a value
9296 in the state monad. It returns the square of its argument, but also
9297 increments the current state value:
9301 (mlet %state-monad ((count (current-state)))
9302 (mbegin %state-monad
9303 (set-current-state (+ 1 count))
9306 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9311 When ``run'' through @code{%state-monad}, we obtain that additional state
9312 value, which is the number of @code{square} calls.
9315 @deffn {Monadic Procedure} current-state
9316 Return the current state as a monadic value.
9319 @deffn {Monadic Procedure} set-current-state @var{value}
9320 Set the current state to @var{value} and return the previous state as a
9324 @deffn {Monadic Procedure} state-push @var{value}
9325 Push @var{value} to the current state, which is assumed to be a list,
9326 and return the previous state as a monadic value.
9329 @deffn {Monadic Procedure} state-pop
9330 Pop a value from the current state and return it as a monadic value.
9331 The state is assumed to be a list.
9334 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9335 Run monadic value @var{mval} starting with @var{state} as the initial
9336 state. Return two values: the resulting value, and the resulting state.
9339 The main interface to the store monad, provided by the @code{(guix
9340 store)} module, is as follows.
9342 @defvr {Scheme Variable} %store-monad
9343 The store monad---an alias for @code{%state-monad}.
9345 Values in the store monad encapsulate accesses to the store. When its
9346 effect is needed, a value of the store monad must be ``evaluated'' by
9347 passing it to the @code{run-with-store} procedure (see below).
9350 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9351 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9352 open store connection.
9355 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9356 Return as a monadic value the absolute file name in the store of the file
9357 containing @var{text}, a string. @var{references} is a list of store items that the
9358 resulting text file refers to; it defaults to the empty list.
9361 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9362 Return as a monadic value the absolute file name in the store of the file
9363 containing @var{data}, a bytevector. @var{references} is a list of store
9364 items that the resulting binary file refers to; it defaults to the empty list.
9367 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9368 [#:recursive? #t] [#:select? (const #t)]
9369 Return the name of @var{file} once interned in the store. Use
9370 @var{name} as its store name, or the basename of @var{file} if
9371 @var{name} is omitted.
9373 When @var{recursive?} is true, the contents of @var{file} are added
9374 recursively; if @var{file} designates a flat file and @var{recursive?}
9375 is true, its contents are added, and its permission bits are kept.
9377 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9378 @var{stat})} for each directory entry, where @var{file} is the entry's
9379 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9380 entries for which @var{select?} does not return true.
9382 The example below adds a file to the store, under two different names:
9385 (run-with-store (open-connection)
9386 (mlet %store-monad ((a (interned-file "README"))
9387 (b (interned-file "README" "LEGU-MIN")))
9388 (return (list a b))))
9390 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9395 The @code{(guix packages)} module exports the following package-related
9398 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9399 [#:system (%current-system)] [#:target #f] @
9402 value in the absolute file name of @var{file} within the @var{output}
9403 directory of @var{package}. When @var{file} is omitted, return the name
9404 of the @var{output} directory of @var{package}. When @var{target} is
9405 true, use it as a cross-compilation target triplet.
9407 Note that this procedure does @emph{not} build @var{package}. Thus, the
9408 result might or might not designate an existing file. We recommend not
9409 using this procedure unless you know what you are doing.
9412 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9413 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9414 @var{target} [@var{system}]
9415 Monadic version of @code{package-derivation} and
9416 @code{package-cross-derivation} (@pxref{Defining Packages}).
9421 @section G-Expressions
9423 @cindex G-expression
9424 @cindex build code quoting
9425 So we have ``derivations'', which represent a sequence of build actions
9426 to be performed to produce an item in the store (@pxref{Derivations}).
9427 These build actions are performed when asking the daemon to actually
9428 build the derivations; they are run by the daemon in a container
9429 (@pxref{Invoking guix-daemon}).
9431 @cindex code staging
9432 @cindex staging, of code
9433 @cindex strata of code
9434 It should come as no surprise that we like to write these build actions
9435 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9436 code@footnote{The term @dfn{stratum} in this context was coined by
9437 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9438 Kiselyov, who has written insightful
9439 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9440 on this topic}, refers to this kind of code generation as
9441 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9442 to the daemon, etc.---and the ``build code''---code that actually
9443 performs build actions, such as making directories, invoking
9444 @command{make}, and so on (@pxref{Build Phases}).
9446 To describe a derivation and its build actions, one typically needs to
9447 embed build code inside host code. It boils down to manipulating build
9448 code as data, and the homoiconicity of Scheme---code has a direct
9449 representation as data---comes in handy for that. But we need more than
9450 the normal @code{quasiquote} mechanism in Scheme to construct build
9453 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9454 S-expressions adapted to build expressions. G-expressions, or
9455 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9456 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9457 @code{#$}, and @code{#$@@}), which are comparable to
9458 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9459 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9460 GNU Guile Reference Manual}). However, there are major differences:
9464 Gexps are meant to be written to a file and run or manipulated by other
9468 When a high-level object such as a package or derivation is unquoted
9469 inside a gexp, the result is as if its output file name had been
9473 Gexps carry information about the packages or derivations they refer to,
9474 and these dependencies are automatically added as inputs to the build
9475 processes that use them.
9478 @cindex lowering, of high-level objects in gexps
9479 This mechanism is not limited to package and derivation
9480 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9481 derivations or files in the store can be defined,
9482 such that these objects can also be inserted
9483 into gexps. For example, a useful type of high-level objects that can be
9484 inserted in a gexp is ``file-like objects'', which make it easy to
9485 add files to the store and to refer to them in
9486 derivations and such (see @code{local-file} and @code{plain-file}
9489 To illustrate the idea, here is an example of a gexp:
9496 (symlink (string-append #$coreutils "/bin/ls")
9500 This gexp can be passed to @code{gexp->derivation}; we obtain a
9501 derivation that builds a directory containing exactly one symlink to
9502 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9505 (gexp->derivation "the-thing" build-exp)
9508 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9509 substituted to the reference to the @var{coreutils} package in the
9510 actual build code, and @var{coreutils} is automatically made an input to
9511 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9512 output)}) is replaced by a string containing the directory name of the
9513 output of the derivation.
9515 @cindex cross compilation
9516 In a cross-compilation context, it is useful to distinguish between
9517 references to the @emph{native} build of a package---that can run on the
9518 host---versus references to cross builds of a package. To that end, the
9519 @code{#+} plays the same role as @code{#$}, but is a reference to a
9520 native package build:
9523 (gexp->derivation "vi"
9526 (mkdir (string-append #$output "/bin"))
9527 (system* (string-append #+coreutils "/bin/ln")
9529 (string-append #$emacs "/bin/emacs")
9530 (string-append #$output "/bin/vi")))
9531 #:target "aarch64-linux-gnu")
9535 In the example above, the native build of @var{coreutils} is used, so
9536 that @command{ln} can actually run on the host; but then the
9537 cross-compiled build of @var{emacs} is referenced.
9539 @cindex imported modules, for gexps
9540 @findex with-imported-modules
9541 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9542 able to use certain Guile modules from the ``host environment'' in the
9543 gexp, so those modules should be imported in the ``build environment''.
9544 The @code{with-imported-modules} form allows you to express that:
9547 (let ((build (with-imported-modules '((guix build utils))
9549 (use-modules (guix build utils))
9550 (mkdir-p (string-append #$output "/bin"))))))
9551 (gexp->derivation "empty-dir"
9554 (display "success!\n")
9559 In this example, the @code{(guix build utils)} module is automatically
9560 pulled into the isolated build environment of our gexp, such that
9561 @code{(use-modules (guix build utils))} works as expected.
9563 @cindex module closure
9564 @findex source-module-closure
9565 Usually you want the @emph{closure} of the module to be imported---i.e.,
9566 the module itself and all the modules it depends on---rather than just
9567 the module; failing to do that, attempts to use the module will fail
9568 because of missing dependent modules. The @code{source-module-closure}
9569 procedure computes the closure of a module by looking at its source file
9570 headers, which comes in handy in this case:
9573 (use-modules (guix modules)) ;for 'source-module-closure'
9575 (with-imported-modules (source-module-closure
9576 '((guix build utils)
9578 (gexp->derivation "something-with-vms"
9580 (use-modules (guix build utils)
9585 @cindex extensions, for gexps
9586 @findex with-extensions
9587 In the same vein, sometimes you want to import not just pure-Scheme
9588 modules, but also ``extensions'' such as Guile bindings to C libraries
9589 or other ``full-blown'' packages. Say you need the @code{guile-json}
9590 package available on the build side, here's how you would do it:
9593 (use-modules (gnu packages guile)) ;for 'guile-json'
9595 (with-extensions (list guile-json)
9596 (gexp->derivation "something-with-json"
9598 (use-modules (json))
9602 The syntactic form to construct gexps is summarized below.
9604 @deffn {Scheme Syntax} #~@var{exp}
9605 @deffnx {Scheme Syntax} (gexp @var{exp})
9606 Return a G-expression containing @var{exp}. @var{exp} may contain one
9607 or more of the following forms:
9611 @itemx (ungexp @var{obj})
9612 Introduce a reference to @var{obj}. @var{obj} may have one of the
9613 supported types, for example a package or a
9614 derivation, in which case the @code{ungexp} form is replaced by its
9615 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9617 If @var{obj} is a list, it is traversed and references to supported
9618 objects are substituted similarly.
9620 If @var{obj} is another gexp, its contents are inserted and its
9621 dependencies are added to those of the containing gexp.
9623 If @var{obj} is another kind of object, it is inserted as is.
9625 @item #$@var{obj}:@var{output}
9626 @itemx (ungexp @var{obj} @var{output})
9627 This is like the form above, but referring explicitly to the
9628 @var{output} of @var{obj}---this is useful when @var{obj} produces
9629 multiple outputs (@pxref{Packages with Multiple Outputs}).
9632 @itemx #+@var{obj}:output
9633 @itemx (ungexp-native @var{obj})
9634 @itemx (ungexp-native @var{obj} @var{output})
9635 Same as @code{ungexp}, but produces a reference to the @emph{native}
9636 build of @var{obj} when used in a cross compilation context.
9638 @item #$output[:@var{output}]
9639 @itemx (ungexp output [@var{output}])
9640 Insert a reference to derivation output @var{output}, or to the main
9641 output when @var{output} is omitted.
9643 This only makes sense for gexps passed to @code{gexp->derivation}.
9646 @itemx (ungexp-splicing @var{lst})
9647 Like the above, but splices the contents of @var{lst} inside the
9651 @itemx (ungexp-native-splicing @var{lst})
9652 Like the above, but refers to native builds of the objects listed in
9657 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9658 of the @code{gexp?} type (see below).
9661 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9662 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9663 in their execution environment.
9665 Each item in @var{modules} can be the name of a module, such as
9666 @code{(guix build utils)}, or it can be a module name, followed by an
9667 arrow, followed by a file-like object:
9670 `((guix build utils)
9672 ((guix config) => ,(scheme-file "config.scm"
9673 #~(define-module @dots{}))))
9677 In the example above, the first two modules are taken from the search
9678 path, and the last one is created from the given file-like object.
9680 This form has @emph{lexical} scope: it has an effect on the gexps
9681 directly defined in @var{body}@dots{}, but not on those defined, say, in
9682 procedures called from @var{body}@dots{}.
9685 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9686 Mark the gexps defined in @var{body}@dots{} as requiring
9687 @var{extensions} in their build and execution environment.
9688 @var{extensions} is typically a list of package objects such as those
9689 defined in the @code{(gnu packages guile)} module.
9691 Concretely, the packages listed in @var{extensions} are added to the
9692 load path while compiling imported modules in @var{body}@dots{}; they
9693 are also added to the load path of the gexp returned by
9697 @deffn {Scheme Procedure} gexp? @var{obj}
9698 Return @code{#t} if @var{obj} is a G-expression.
9701 G-expressions are meant to be written to disk, either as code building
9702 some derivation, or as plain files in the store. The monadic procedures
9703 below allow you to do that (@pxref{The Store Monad}, for more
9704 information about monads).
9706 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9707 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9708 [#:hash #f] [#:hash-algo #f] @
9709 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9710 [#:module-path @code{%load-path}] @
9711 [#:effective-version "2.2"] @
9712 [#:references-graphs #f] [#:allowed-references #f] @
9713 [#:disallowed-references #f] @
9714 [#:leaked-env-vars #f] @
9715 [#:script-name (string-append @var{name} "-builder")] @
9716 [#:deprecation-warnings #f] @
9717 [#:local-build? #f] [#:substitutable? #t] @
9718 [#:properties '()] [#:guile-for-build #f]
9719 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9720 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9721 stored in a file called @var{script-name}. When @var{target} is true,
9722 it is used as the cross-compilation target triplet for packages referred
9725 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9727 make @var{modules} available in the evaluation context of @var{exp};
9728 @var{modules} is a list of names of Guile modules searched in
9729 @var{module-path} to be copied in the store, compiled, and made available in
9730 the load path during the execution of @var{exp}---e.g., @code{((guix
9731 build utils) (guix build gnu-build-system))}.
9733 @var{effective-version} determines the string to use when adding extensions of
9734 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9736 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9739 When @var{references-graphs} is true, it must be a list of tuples of one of the
9743 (@var{file-name} @var{package})
9744 (@var{file-name} @var{package} @var{output})
9745 (@var{file-name} @var{derivation})
9746 (@var{file-name} @var{derivation} @var{output})
9747 (@var{file-name} @var{store-item})
9750 The right-hand-side of each element of @var{references-graphs} is automatically made
9751 an input of the build process of @var{exp}. In the build environment, each
9752 @var{file-name} contains the reference graph of the corresponding item, in a simple
9755 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9756 In the latter case, the list denotes store items that the result is allowed to
9757 refer to. Any reference to another store item will lead to a build error.
9758 Similarly for @var{disallowed-references}, which can list items that must not be
9759 referenced by the outputs.
9761 @var{deprecation-warnings} determines whether to show deprecation warnings while
9762 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9764 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9767 @cindex file-like objects
9768 The @code{local-file}, @code{plain-file}, @code{computed-file},
9769 @code{program-file}, and @code{scheme-file} procedures below return
9770 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9771 these objects lead to a file in the store. Consider this G-expression:
9774 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9775 #$(local-file "/tmp/my-nscd.conf"))
9778 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9779 to the store. Once expanded, for instance @i{via}
9780 @code{gexp->derivation}, the G-expression refers to that copy under
9781 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9782 does not have any effect on what the G-expression does.
9783 @code{plain-file} can be used similarly; it differs in that the file
9784 content is directly passed as a string.
9786 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9787 [#:recursive? #f] [#:select? (const #t)]
9788 Return an object representing local file @var{file} to add to the store;
9789 this object can be used in a gexp. If @var{file} is a literal string
9790 denoting a relative file name, it is looked up relative to the source
9791 file where it appears; if @var{file} is not a literal string, it is
9792 looked up relative to the current working directory at run time.
9793 @var{file} will be added to the store under @var{name}--by default the
9794 base name of @var{file}.
9796 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9797 designates a flat file and @var{recursive?} is true, its contents are added, and its
9798 permission bits are kept.
9800 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9801 @var{stat})} for each directory entry, where @var{file} is the entry's
9802 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9803 entries for which @var{select?} does not return true.
9805 This is the declarative counterpart of the @code{interned-file} monadic
9806 procedure (@pxref{The Store Monad, @code{interned-file}}).
9809 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9810 Return an object representing a text file called @var{name} with the given
9811 @var{content} (a string or a bytevector) to be added to the store.
9813 This is the declarative counterpart of @code{text-file}.
9816 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9819 Return an object representing the store item @var{name}, a file or
9820 directory computed by @var{gexp}. When @var{local-build?} is true (the
9821 default), the derivation is built locally. @var{options} is a list of
9822 additional arguments to pass to @code{gexp->derivation}.
9824 This is the declarative counterpart of @code{gexp->derivation}.
9827 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9828 [#:guile (default-guile)] [#:module-path %load-path] @
9829 [#:system (%current-system)] [#:target #f]
9830 Return an executable script @var{name} that runs @var{exp} using
9831 @var{guile}, with @var{exp}'s imported modules in its search path.
9832 Look up @var{exp}'s modules in @var{module-path}.
9834 The example below builds a script that simply invokes the @command{ls}
9838 (use-modules (guix gexp) (gnu packages base))
9840 (gexp->script "list-files"
9841 #~(execl #$(file-append coreutils "/bin/ls")
9845 When ``running'' it through the store (@pxref{The Store Monad,
9846 @code{run-with-store}}), we obtain a derivation that produces an
9847 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9850 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9852 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9856 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9857 [#:guile #f] [#:module-path %load-path]
9858 Return an object representing the executable store item @var{name} that
9859 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9860 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9862 This is the declarative counterpart of @code{gexp->script}.
9865 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9866 [#:set-load-path? #t] [#:module-path %load-path] @
9868 [#:guile (default-guile)]
9869 Return a derivation that builds a file @var{name} containing @var{exp}.
9870 When @var{splice?} is true, @var{exp} is considered to be a list of
9871 expressions that will be spliced in the resulting file.
9873 When @var{set-load-path?} is true, emit code in the resulting file to
9874 set @code{%load-path} and @code{%load-compiled-path} to honor
9875 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9878 The resulting file holds references to all the dependencies of @var{exp}
9879 or a subset thereof.
9882 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9883 [#:splice? #f] [#:set-load-path? #t]
9884 Return an object representing the Scheme file @var{name} that contains
9887 This is the declarative counterpart of @code{gexp->file}.
9890 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9891 Return as a monadic value a derivation that builds a text file
9892 containing all of @var{text}. @var{text} may list, in addition to
9893 strings, objects of any type that can be used in a gexp: packages,
9894 derivations, local file objects, etc. The resulting store file holds
9895 references to all these.
9897 This variant should be preferred over @code{text-file} anytime the file
9898 to create will reference items from the store. This is typically the
9899 case when building a configuration file that embeds store file names,
9903 (define (profile.sh)
9904 ;; Return the name of a shell script in the store that
9905 ;; initializes the 'PATH' environment variable.
9906 (text-file* "profile.sh"
9907 "export PATH=" coreutils "/bin:"
9908 grep "/bin:" sed "/bin\n"))
9911 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9912 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9913 preventing them from being garbage-collected during its lifetime.
9916 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9917 Return an object representing store file @var{name} containing
9918 @var{text}. @var{text} is a sequence of strings and file-like objects,
9922 (mixed-text-file "profile"
9923 "export PATH=" coreutils "/bin:" grep "/bin")
9926 This is the declarative counterpart of @code{text-file*}.
9929 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9930 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9931 Each item in @var{files} must be a two-element list where the first element is the
9932 file name to use in the new directory, and the second element is a gexp
9933 denoting the target file. Here's an example:
9937 `(("hosts" ,(plain-file "hosts"
9938 "127.0.0.1 localhost"))
9939 ("bashrc" ,(plain-file "bashrc"
9940 "alias ls='ls --color=auto'"))))
9943 This yields an @code{etc} directory containing these two files.
9946 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9947 Return a directory that is the union of @var{things}, where @var{things} is a list of
9948 file-like objects denoting directories. For example:
9951 (directory-union "guile+emacs" (list guile emacs))
9954 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9957 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9958 Return a file-like object that expands to the concatenation of @var{obj}
9959 and @var{suffix}, where @var{obj} is a lowerable object and each
9960 @var{suffix} is a string.
9962 As an example, consider this gexp:
9965 (gexp->script "run-uname"
9966 #~(system* #$(file-append coreutils
9970 The same effect could be achieved with:
9973 (gexp->script "run-uname"
9974 #~(system* (string-append #$coreutils
9978 There is one difference though: in the @code{file-append} case, the
9979 resulting script contains the absolute file name as a string, whereas in
9980 the second case, the resulting script contains a @code{(string-append
9981 @dots{})} expression to construct the file name @emph{at run time}.
9984 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9985 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9986 Bind @var{system} to the currently targeted system---e.g.,
9987 @code{"x86_64-linux"}---within @var{body}.
9989 In the second case, additionally bind @var{target} to the current
9990 cross-compilation target---a GNU triplet such as
9991 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9994 @code{let-system} is useful in the occasional case where the object
9995 spliced into the gexp depends on the target system, as in this example:
9999 #+(let-system system
10000 (cond ((string-prefix? "armhf-" system)
10001 (file-append qemu "/bin/qemu-system-arm"))
10002 ((string-prefix? "x86_64-" system)
10003 (file-append qemu "/bin/qemu-system-x86_64"))
10005 (error "dunno!"))))
10006 "-net" "user" #$image)
10010 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
10011 This macro is similar to the @code{parameterize} form for
10012 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
10013 Guile Reference Manual}). The key difference is that it takes effect
10014 when the file-like object returned by @var{exp} is lowered to a
10015 derivation or store item.
10017 A typical use of @code{with-parameters} is to force the system in effect
10018 for a given object:
10021 (with-parameters ((%current-system "i686-linux"))
10025 The example above returns an object that corresponds to the i686 build
10026 of Coreutils, regardless of the current value of @code{%current-system}.
10030 Of course, in addition to gexps embedded in ``host'' code, there are
10031 also modules containing build tools. To make it clear that they are
10032 meant to be used in the build stratum, these modules are kept in the
10033 @code{(guix build @dots{})} name space.
10035 @cindex lowering, of high-level objects in gexps
10036 Internally, high-level objects are @dfn{lowered}, using their compiler,
10037 to either derivations or store items. For instance, lowering a package
10038 yields a derivation, and lowering a @code{plain-file} yields a store
10039 item. This is achieved using the @code{lower-object} monadic procedure.
10041 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
10043 Return as a value in @code{%store-monad} the derivation or store item
10044 corresponding to @var{obj} for @var{system}, cross-compiling for
10045 @var{target} if @var{target} is true. @var{obj} must be an object that
10046 has an associated gexp compiler, such as a @code{<package>}.
10049 @deffn {Procedure} gexp->approximate-sexp @var{gexp}
10050 Sometimes, it may be useful to convert a G-exp into a S-exp. For
10051 example, some linters (@pxref{Invoking guix lint}) peek into the build
10052 phases of a package to detect potential problems. This conversion can
10053 be achieved with this procedure. However, some information can be lost
10054 in the process. More specifically, lowerable objects will be silently
10055 replaced with some arbitrary object -- currently the list
10056 @code{(*approximate*)}, but this may change.
10059 @node Invoking guix repl
10060 @section Invoking @command{guix repl}
10062 @cindex REPL, read-eval-print loop, script
10063 The @command{guix repl} command makes it easier to program Guix in Guile
10064 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
10065 programming (@pxref{Using Guile Interactively,,, guile,
10066 GNU Guile Reference Manual}), or by running Guile scripts
10067 (@pxref{Running Guile Scripts,,, guile,
10068 GNU Guile Reference Manual}).
10069 Compared to just launching the @command{guile}
10070 command, @command{guix repl} guarantees that all the Guix modules and all its
10071 dependencies are available in the search path.
10073 The general syntax is:
10076 guix repl @var{options} [@var{file} @var{args}]
10079 When a @var{file} argument is provided, @var{file} is
10080 executed as a Guile scripts:
10083 guix repl my-script.scm
10086 To pass arguments to the script, use @code{--} to prevent them from
10087 being interpreted as arguments to @command{guix repl} itself:
10090 guix repl -- my-script.scm --input=foo.txt
10093 To make a script executable directly from the shell, using the guix
10094 executable that is on the user's search path, add the following two
10095 lines at the top of the script:
10098 @code{#!/usr/bin/env -S guix repl --}
10102 Without a file name argument, a Guile REPL is started:
10106 scheme@@(guile-user)> ,use (gnu packages base)
10107 scheme@@(guile-user)> coreutils
10108 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
10112 In addition, @command{guix repl} implements a simple machine-readable REPL
10113 protocol for use by @code{(guix inferior)}, a facility to interact with
10114 @dfn{inferiors}, separate processes running a potentially different revision
10117 The available options are as follows:
10120 @item --type=@var{type}
10121 @itemx -t @var{type}
10122 Start a REPL of the given @var{TYPE}, which can be one of the following:
10126 This is default, and it spawns a standard full-featured Guile REPL.
10128 Spawn a REPL that uses the machine-readable protocol. This is the protocol
10129 that the @code{(guix inferior)} module speaks.
10132 @item --listen=@var{endpoint}
10133 By default, @command{guix repl} reads from standard input and writes to
10134 standard output. When this option is passed, it will instead listen for
10135 connections on @var{endpoint}. Here are examples of valid options:
10138 @item --listen=tcp:37146
10139 Accept connections on localhost on port 37146.
10141 @item --listen=unix:/tmp/socket
10142 Accept connections on the Unix-domain socket @file{/tmp/socket}.
10145 @item --load-path=@var{directory}
10146 @itemx -L @var{directory}
10147 Add @var{directory} to the front of the package module search path
10148 (@pxref{Package Modules}).
10150 This allows users to define their own packages and make them visible to
10151 the script or REPL.
10154 Inhibit loading of the @file{~/.guile} file. By default, that
10155 configuration file is loaded when spawning a @code{guile} REPL.
10158 @c *********************************************************************
10162 This section describes Guix command-line utilities. Some of them are
10163 primarily targeted at developers and users who write new package
10164 definitions, while others are more generally useful. They complement
10165 the Scheme programming interface of Guix in a convenient way.
10168 * Invoking guix build:: Building packages from the command line.
10169 * Invoking guix edit:: Editing package definitions.
10170 * Invoking guix download:: Downloading a file and printing its hash.
10171 * Invoking guix hash:: Computing the cryptographic hash of a file.
10172 * Invoking guix import:: Importing package definitions.
10173 * Invoking guix refresh:: Updating package definitions.
10174 * Invoking guix lint:: Finding errors in package definitions.
10175 * Invoking guix size:: Profiling disk usage.
10176 * Invoking guix graph:: Visualizing the graph of packages.
10177 * Invoking guix publish:: Sharing substitutes.
10178 * Invoking guix challenge:: Challenging substitute servers.
10179 * Invoking guix copy:: Copying to and from a remote store.
10180 * Invoking guix container:: Process isolation.
10181 * Invoking guix weather:: Assessing substitute availability.
10182 * Invoking guix processes:: Listing client processes.
10185 @node Invoking guix build
10186 @section Invoking @command{guix build}
10188 @cindex package building
10189 @cindex @command{guix build}
10190 The @command{guix build} command builds packages or derivations and
10191 their dependencies, and prints the resulting store paths. Note that it
10192 does not modify the user's profile---this is the job of the
10193 @command{guix package} command (@pxref{Invoking guix package}). Thus,
10194 it is mainly useful for distribution developers.
10196 The general syntax is:
10199 guix build @var{options} @var{package-or-derivation}@dots{}
10202 As an example, the following command builds the latest versions of Emacs
10203 and of Guile, displays their build logs, and finally displays the
10204 resulting directories:
10207 guix build emacs guile
10210 Similarly, the following command builds all the available packages:
10213 guix build --quiet --keep-going \
10214 $(guix package -A | cut -f1,2 --output-delimiter=@@)
10217 @var{package-or-derivation} may be either the name of a package found in
10218 the software distribution such as @code{coreutils} or
10219 @code{coreutils@@8.20}, or a derivation such as
10220 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
10221 package with the corresponding name (and optionally version) is searched
10222 for among the GNU distribution modules (@pxref{Package Modules}).
10224 Alternatively, the @option{--expression} option may be used to specify a
10225 Scheme expression that evaluates to a package; this is useful when
10226 disambiguating among several same-named packages or package variants is
10229 There may be zero or more @var{options}. The available options are
10230 described in the subsections below.
10233 * Common Build Options:: Build options for most commands.
10234 * Package Transformation Options:: Creating variants of packages.
10235 * Additional Build Options:: Options specific to 'guix build'.
10236 * Debugging Build Failures:: Real life packaging experience.
10239 @node Common Build Options
10240 @subsection Common Build Options
10242 A number of options that control the build process are common to
10243 @command{guix build} and other commands that can spawn builds, such as
10244 @command{guix package} or @command{guix archive}. These are the
10249 @item --load-path=@var{directory}
10250 @itemx -L @var{directory}
10251 Add @var{directory} to the front of the package module search path
10252 (@pxref{Package Modules}).
10254 This allows users to define their own packages and make them visible to
10255 the command-line tools.
10257 @item --keep-failed
10259 Keep the build tree of failed builds. Thus, if a build fails, its build
10260 tree is kept under @file{/tmp}, in a directory whose name is shown at
10261 the end of the build log. This is useful when debugging build issues.
10262 @xref{Debugging Build Failures}, for tips and tricks on how to debug
10265 This option implies @option{--no-offload}, and it has no effect when
10266 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
10267 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
10271 Keep going when some of the derivations fail to build; return only once
10272 all the builds have either completed or failed.
10274 The default behavior is to stop as soon as one of the specified
10275 derivations has failed.
10279 Do not build the derivations.
10281 @anchor{fallback-option}
10283 When substituting a pre-built binary fails, fall back to building
10284 packages locally (@pxref{Substitution Failure}).
10286 @item --substitute-urls=@var{urls}
10287 @anchor{client-substitute-urls}
10288 Consider @var{urls} the whitespace-separated list of substitute source
10289 URLs, overriding the default list of URLs of @command{guix-daemon}
10290 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
10292 This means that substitutes may be downloaded from @var{urls}, provided
10293 they are signed by a key authorized by the system administrator
10294 (@pxref{Substitutes}).
10296 When @var{urls} is the empty string, substitutes are effectively
10299 @item --no-substitutes
10300 Do not use substitutes for build products. That is, always build things
10301 locally instead of allowing downloads of pre-built binaries
10302 (@pxref{Substitutes}).
10305 Do not ``graft'' packages. In practice, this means that package updates
10306 available as grafts are not applied. @xref{Security Updates}, for more
10307 information on grafts.
10309 @item --rounds=@var{n}
10310 Build each derivation @var{n} times in a row, and raise an error if
10311 consecutive build results are not bit-for-bit identical.
10313 This is a useful way to detect non-deterministic builds processes.
10314 Non-deterministic build processes are a problem because they make it
10315 practically impossible for users to @emph{verify} whether third-party
10316 binaries are genuine. @xref{Invoking guix challenge}, for more.
10318 When used in conjunction with @option{--keep-failed}, the differing
10319 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10320 This makes it easy to look for differences between the two results.
10323 Do not use offload builds to other machines (@pxref{Daemon Offload
10324 Setup}). That is, always build things locally instead of offloading
10325 builds to remote machines.
10327 @item --max-silent-time=@var{seconds}
10328 When the build or substitution process remains silent for more than
10329 @var{seconds}, terminate it and report a build failure.
10331 By default, the daemon's setting is honored (@pxref{Invoking
10332 guix-daemon, @option{--max-silent-time}}).
10334 @item --timeout=@var{seconds}
10335 Likewise, when the build or substitution process lasts for more than
10336 @var{seconds}, terminate it and report a build failure.
10338 By default, the daemon's setting is honored (@pxref{Invoking
10339 guix-daemon, @option{--timeout}}).
10341 @c Note: This option is actually not part of %standard-build-options but
10342 @c most programs honor it.
10343 @cindex verbosity, of the command-line tools
10344 @cindex build logs, verbosity
10345 @item -v @var{level}
10346 @itemx --verbosity=@var{level}
10347 Use the given verbosity @var{level}, an integer. Choosing 0 means that
10348 no output is produced, 1 is for quiet output; 2 is similar to 1 but it
10349 additionally displays download URLs; 3 shows all the build log output on
10352 @item --cores=@var{n}
10354 Allow the use of up to @var{n} CPU cores for the build. The special
10355 value @code{0} means to use as many CPU cores as available.
10357 @item --max-jobs=@var{n}
10359 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10360 guix-daemon, @option{--max-jobs}}, for details about this option and the
10361 equivalent @command{guix-daemon} option.
10363 @item --debug=@var{level}
10364 Produce debugging output coming from the build daemon. @var{level} must be an
10365 integer between 0 and 5; higher means more verbose output. Setting a level of
10366 4 or more may be helpful when debugging setup issues with the build daemon.
10370 Behind the scenes, @command{guix build} is essentially an interface to
10371 the @code{package-derivation} procedure of the @code{(guix packages)}
10372 module, and to the @code{build-derivations} procedure of the @code{(guix
10373 derivations)} module.
10375 In addition to options explicitly passed on the command line,
10376 @command{guix build} and other @command{guix} commands that support
10377 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10379 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10380 Users can define this variable to a list of command line options that
10381 will automatically be used by @command{guix build} and other
10382 @command{guix} commands that can perform builds, as in the example
10386 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10389 These options are parsed independently, and the result is appended to
10390 the parsed command-line options.
10394 @node Package Transformation Options
10395 @subsection Package Transformation Options
10397 @cindex package variants
10398 Another set of command-line options supported by @command{guix build}
10399 and also @command{guix package} are @dfn{package transformation
10400 options}. These are options that make it possible to define @dfn{package
10401 variants}---for instance, packages built from different source code.
10402 This is a convenient way to create customized packages on the fly
10403 without having to type in the definitions of package variants
10404 (@pxref{Defining Packages}).
10406 Package transformation options are preserved across upgrades:
10407 @command{guix upgrade} attempts to apply transformation options
10408 initially used when creating the profile to the upgraded packages.
10410 The available options are listed below. Most commands support them and
10411 also support a @option{--help-transform} option that lists all the
10412 available options and a synopsis (these options are not shown in the
10413 @option{--help} output for brevity).
10417 @item --with-source=@var{source}
10418 @itemx --with-source=@var{package}=@var{source}
10419 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10420 Use @var{source} as the source of @var{package}, and @var{version} as
10421 its version number.
10422 @var{source} must be a file name or a URL, as for @command{guix
10423 download} (@pxref{Invoking guix download}).
10425 When @var{package} is omitted,
10426 it is taken to be the package name specified on the
10427 command line that matches the base of @var{source}---e.g.,
10428 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10429 package is @code{guile}.
10431 Likewise, when @var{version} is omitted, the version string is inferred from
10432 @var{source}; in the previous example, it is @code{2.0.10}.
10434 This option allows users to try out versions of packages other than the
10435 one provided by the distribution. The example below downloads
10436 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10437 the @code{ed} package:
10440 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10443 As a developer, @option{--with-source} makes it easy to test release
10447 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10450 @dots{} or to build from a checkout in a pristine environment:
10453 $ git clone git://git.sv.gnu.org/guix.git
10454 $ guix build guix --with-source=guix@@1.0=./guix
10457 @item --with-input=@var{package}=@var{replacement}
10458 Replace dependency on @var{package} by a dependency on
10459 @var{replacement}. @var{package} must be a package name, and
10460 @var{replacement} must be a package specification such as @code{guile}
10461 or @code{guile@@1.8}.
10463 For instance, the following command builds Guix, but replaces its
10464 dependency on the current stable version of Guile with a dependency on
10465 the legacy version of Guile, @code{guile@@2.0}:
10468 guix build --with-input=guile=guile@@2.0 guix
10471 This is a recursive, deep replacement. So in this example, both
10472 @code{guix} and its dependency @code{guile-json} (which also depends on
10473 @code{guile}) get rebuilt against @code{guile@@2.0}.
10475 This is implemented using the @code{package-input-rewriting} Scheme
10476 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10478 @item --with-graft=@var{package}=@var{replacement}
10479 This is similar to @option{--with-input} but with an important difference:
10480 instead of rebuilding the whole dependency chain, @var{replacement} is
10481 built and then @dfn{grafted} onto the binaries that were initially
10482 referring to @var{package}. @xref{Security Updates}, for more
10483 information on grafts.
10485 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10486 and all its dependencies, replacing references to the version of GnuTLS
10487 they currently refer to:
10490 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10493 This has the advantage of being much faster than rebuilding everything.
10494 But there is a caveat: it works if and only if @var{package} and
10495 @var{replacement} are strictly compatible---for example, if they provide
10496 a library, the application binary interface (ABI) of those libraries
10497 must be compatible. If @var{replacement} is somehow incompatible with
10498 @var{package}, then the resulting package may be unusable. Use with
10501 @cindex debugging info, rebuilding
10502 @item --with-debug-info=@var{package}
10503 Build @var{package} in a way that preserves its debugging info and graft
10504 it onto packages that depend on it. This is useful if @var{package}
10505 does not already provide debugging info as a @code{debug} output
10506 (@pxref{Installing Debugging Files}).
10508 For example, suppose you're experiencing a crash in Inkscape and would
10509 like to see what's up in GLib, a library deep down in Inkscape's
10510 dependency graph. GLib lacks a @code{debug} output, so debugging is
10511 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10515 guix install inkscape --with-debug-info=glib
10518 Only GLib needs to be recompiled so this takes a reasonable amount of
10519 time. @xref{Installing Debugging Files}, for more info.
10522 Under the hood, this option works by passing the @samp{#:strip-binaries?
10523 #f} to the build system of the package of interest (@pxref{Build
10524 Systems}). Most build systems support that option but some do not. In
10525 that case, an error is raised.
10527 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10528 the case), debugging info will remain unavailable even when
10529 @code{#:strip-binaries?} is false.
10532 @cindex tool chain, changing the build tool chain of a package
10533 @item --with-c-toolchain=@var{package}=@var{toolchain}
10534 This option changes the compilation of @var{package} and everything that
10535 depends on it so that they get built with @var{toolchain} instead of the
10536 default GNU tool chain for C/C++.
10538 Consider this example:
10541 guix build octave-cli \
10542 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10543 --with-c-toolchain=fftwf=gcc-toolchain@@10
10546 The command above builds a variant of the @code{fftw} and @code{fftwf}
10547 packages using version 10 of @code{gcc-toolchain} instead of the default
10548 tool chain, and then builds a variant of the GNU@tie{}Octave
10549 command-line interface using them. GNU@tie{}Octave itself is also built
10550 with @code{gcc-toolchain@@10}.
10552 This other example builds the Hardware Locality (@code{hwloc}) library
10553 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10557 guix build --with-c-toolchain=hwloc=clang-toolchain \
10558 intel-mpi-benchmarks
10562 There can be application binary interface (ABI) incompatibilities among
10563 tool chains. This is particularly true of the C++ standard library and
10564 run-time support libraries such as that of OpenMP@. By rebuilding all
10565 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10566 the risks of incompatibility but cannot entirely eliminate them. Choose
10567 @var{package} wisely.
10570 @item --with-git-url=@var{package}=@var{url}
10571 @cindex Git, using the latest commit
10572 @cindex latest commit, building
10573 Build @var{package} from the latest commit of the @code{master} branch of the
10574 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10577 For example, the following command builds the NumPy Python library against the
10578 latest commit of the master branch of Python itself:
10581 guix build python-numpy \
10582 --with-git-url=python=https://github.com/python/cpython
10585 This option can also be combined with @option{--with-branch} or
10586 @option{--with-commit} (see below).
10588 @cindex continuous integration
10589 Obviously, since it uses the latest commit of the given branch, the result of
10590 such a command varies over time. Nevertheless it is a convenient way to
10591 rebuild entire software stacks against the latest commit of one or more
10592 packages. This is particularly useful in the context of continuous
10595 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10596 consecutive accesses to the same repository. You may want to clean it up once
10597 in a while to save disk space.
10599 @item --with-branch=@var{package}=@var{branch}
10600 Build @var{package} from the latest commit of @var{branch}. If the
10601 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10602 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10603 repository URL is taken from that @code{source}. Otherwise you have to use
10604 @option{--with-git-url} to specify the URL of the Git repository.
10606 For instance, the following command builds @code{guile-sqlite3} from the
10607 latest commit of its @code{master} branch, and then builds @code{guix} (which
10608 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10609 specific @code{guile-sqlite3} build:
10612 guix build --with-branch=guile-sqlite3=master cuirass
10615 @item --with-commit=@var{package}=@var{commit}
10616 This is similar to @option{--with-branch}, except that it builds from
10617 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10618 Git commit SHA1 identifier or a tag.
10620 @item --with-patch=@var{package}=@var{file}
10621 Add @var{file} to the list of patches applied to @var{package}, where
10622 @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
10623 @var{file} must contain a patch; it is applied with the flags specified
10624 in the @code{origin} of @var{package} (@pxref{origin Reference}), which
10625 by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
10626 Comparing and Merging Files}).
10628 As an example, the command below rebuilds Coreutils with the GNU C
10629 Library (glibc) patched with the given patch:
10632 guix build coreutils --with-patch=glibc=./glibc-frob.patch
10635 In this example, glibc itself as well as everything that leads to
10636 Coreutils in the dependency graph is rebuilt.
10638 @cindex upstream, latest version
10639 @item --with-latest=@var{package}
10640 So you like living on the bleeding edge? This option is for you! It
10641 replaces occurrences of @var{package} in the dependency graph with its
10642 latest upstream version, as reported by @command{guix refresh}
10643 (@pxref{Invoking guix refresh}).
10645 It does so by determining the latest upstream release of @var{package}
10646 (if possible), downloading it, and authenticating it @emph{if} it comes
10647 with an OpenPGP signature.
10649 As an example, the command below builds Guix against the latest version
10653 guix build guix --with-latest=guile-json
10656 There are limitations. First, in cases where the tool cannot or does
10657 not know how to authenticate source code, you are at risk of running
10658 malicious code; a warning is emitted in this case. Second, this option
10659 simply changes the source used in the existing package definitions,
10660 which is not always sufficient: there might be additional dependencies
10661 that need to be added, patches to apply, and more generally the quality
10662 assurance work that Guix developers normally do will be missing.
10664 You've been warned! In all the other cases, it's a snappy way to stay
10665 on top. We encourage you to submit patches updating the actual package
10666 definitions once you have successfully tested an upgrade
10667 (@pxref{Contributing}).
10669 @cindex test suite, skipping
10670 @item --without-tests=@var{package}
10671 Build @var{package} without running its tests. This can be useful in
10672 situations where you want to skip the lengthy test suite of a
10673 intermediate package, or if a package's test suite fails in a
10674 non-deterministic fashion. It should be used with care because running
10675 the test suite is a good way to ensure a package is working as intended.
10677 Turning off tests leads to a different store item. Consequently, when
10678 using this option, anything that depends on @var{package} must be
10679 rebuilt, as in this example:
10682 guix install --without-tests=python python-notebook
10685 The command above installs @code{python-notebook} on top of
10686 @code{python} built without running its test suite. To do so, it also
10687 rebuilds everything that depends on @code{python}, including
10688 @code{python-notebook} itself.
10690 Internally, @option{--without-tests} relies on changing the
10691 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10692 Systems}). Note that some packages use a customized @code{check} phase
10693 that does not respect a @code{#:tests? #f} setting. Therefore,
10694 @option{--without-tests} has no effect on these packages.
10698 Wondering how to achieve the same effect using Scheme code, for example
10699 in your manifest, or how to write your own package transformation?
10700 @xref{Defining Package Variants}, for an overview of the programming
10701 interfaces available.
10703 @node Additional Build Options
10704 @subsection Additional Build Options
10706 The command-line options presented below are specific to @command{guix
10713 Build quietly, without displaying the build log; this is equivalent to
10714 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10715 (or similar) and can always be retrieved using the @option{--log-file} option.
10717 @item --file=@var{file}
10718 @itemx -f @var{file}
10719 Build the package, derivation, or other file-like object that the code within
10720 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10722 As an example, @var{file} might contain a package definition like this
10723 (@pxref{Defining Packages}):
10726 @include package-hello.scm
10729 The @var{file} may also contain a JSON representation of one or more
10730 package definitions. Running @code{guix build -f} on @file{hello.json}
10731 with the following contents would result in building the packages
10732 @code{myhello} and @code{greeter}:
10735 @verbatiminclude package-hello.json
10738 @item --manifest=@var{manifest}
10739 @itemx -m @var{manifest}
10740 Build all packages listed in the given @var{manifest}
10741 (@pxref{profile-manifest, @option{--manifest}}).
10743 @item --expression=@var{expr}
10744 @itemx -e @var{expr}
10745 Build the package or derivation @var{expr} evaluates to.
10747 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10748 guile-1.8)}, which unambiguously designates this specific variant of
10749 version 1.8 of Guile.
10751 Alternatively, @var{expr} may be a G-expression, in which case it is used
10752 as a build program passed to @code{gexp->derivation}
10753 (@pxref{G-Expressions}).
10755 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10756 (@pxref{The Store Monad}). The procedure must return a derivation as a
10757 monadic value, which is then passed through @code{run-with-store}.
10761 Build the source derivations of the packages, rather than the packages
10764 For instance, @code{guix build -S gcc} returns something like
10765 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10768 The returned source tarball is the result of applying any patches and
10769 code snippets specified in the package @code{origin} (@pxref{Defining
10772 @cindex source, verification
10773 As with other derivations, the result of building a source derivation
10774 can be verified using the @option{--check} option (@pxref{build-check}).
10775 This is useful to validate that a (potentially already built or
10776 substituted, thus cached) package source matches against its declared
10779 Note that @command{guix build -S} compiles the sources only of the
10780 specified packages. They do not include the sources of statically
10781 linked dependencies and by themselves are insufficient for reproducing
10785 Fetch and return the source of @var{package-or-derivation} and all their
10786 dependencies, recursively. This is a handy way to obtain a local copy
10787 of all the source code needed to build @var{packages}, allowing you to
10788 eventually build them even without network access. It is an extension
10789 of the @option{--source} option and can accept one of the following
10790 optional argument values:
10794 This value causes the @option{--sources} option to behave in the same way
10795 as the @option{--source} option.
10798 Build the source derivations of all packages, including any source that
10799 might be listed as @code{inputs}. This is the default value.
10802 $ guix build --sources tzdata
10803 The following derivations will be built:
10804 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10805 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10809 Build the source derivations of all packages, as well of all transitive
10810 inputs to the packages. This can be used e.g.@: to
10811 prefetch package source for later offline building.
10814 $ guix build --sources=transitive tzdata
10815 The following derivations will be built:
10816 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10817 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10818 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10819 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10820 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10821 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10827 @item --system=@var{system}
10828 @itemx -s @var{system}
10829 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10830 the system type of the build host. The @command{guix build} command allows
10831 you to repeat this option several times, in which case it builds for all the
10832 specified systems; other commands ignore extraneous @option{-s} options.
10835 The @option{--system} flag is for @emph{native} compilation and must not
10836 be confused with cross-compilation. See @option{--target} below for
10837 information on cross-compilation.
10840 An example use of this is on Linux-based systems, which can emulate
10841 different personalities. For instance, passing
10842 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10843 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10844 you to build packages in a complete 32-bit environment.
10847 Building for an @code{armhf-linux} system is unconditionally enabled on
10848 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10849 allow for this functionality, notably the ThunderX.
10852 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10853 is enabled (@pxref{Virtualization Services,
10854 @code{qemu-binfmt-service-type}}), you can build for any system for
10855 which a QEMU @code{binfmt_misc} handler is installed.
10857 Builds for a system other than that of the machine you are using can
10858 also be offloaded to a remote machine of the right architecture.
10859 @xref{Daemon Offload Setup}, for more information on offloading.
10861 @item --target=@var{triplet}
10862 @cindex cross-compilation
10863 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10864 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10865 configuration triplets,, autoconf, Autoconf}).
10867 @anchor{build-check}
10869 @cindex determinism, checking
10870 @cindex reproducibility, checking
10871 Rebuild @var{package-or-derivation}, which are already available in the
10872 store, and raise an error if the build results are not bit-for-bit
10875 This mechanism allows you to check whether previously installed
10876 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10877 of a package is deterministic. @xref{Invoking guix challenge}, for more
10878 background information and tools.
10880 When used in conjunction with @option{--keep-failed}, the differing
10881 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10882 This makes it easy to look for differences between the two results.
10885 @cindex repairing store items
10886 @cindex corruption, recovering from
10887 Attempt to repair the specified store items, if they are corrupt, by
10888 re-downloading or rebuilding them.
10890 This operation is not atomic and thus restricted to @code{root}.
10892 @item --derivations
10894 Return the derivation paths, not the output paths, of the given
10897 @item --root=@var{file}
10898 @itemx -r @var{file}
10899 @cindex GC roots, adding
10900 @cindex garbage collector roots, adding
10901 Make @var{file} a symlink to the result, and register it as a garbage
10904 Consequently, the results of this @command{guix build} invocation are
10905 protected from garbage collection until @var{file} is removed. When
10906 that option is omitted, build results are eligible for garbage
10907 collection as soon as the build completes. @xref{Invoking guix gc}, for
10911 @cindex build logs, access
10912 Return the build log file names or URLs for the given
10913 @var{package-or-derivation}, or raise an error if build logs are
10916 This works regardless of how packages or derivations are specified. For
10917 instance, the following invocations are equivalent:
10920 guix build --log-file $(guix build -d guile)
10921 guix build --log-file $(guix build guile)
10922 guix build --log-file guile
10923 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10926 If a log is unavailable locally, and unless @option{--no-substitutes} is
10927 passed, the command looks for a corresponding log on one of the
10928 substitute servers (as specified with @option{--substitute-urls}).
10930 So for instance, imagine you want to see the build log of GDB on MIPS,
10931 but you are actually on an @code{x86_64} machine:
10934 $ guix build --log-file gdb -s aarch64-linux
10935 https://@value{SUBSTITUTE-SERVER-1}/log/@dots{}-gdb-7.10
10938 You can freely access a huge library of build logs!
10941 @node Debugging Build Failures
10942 @subsection Debugging Build Failures
10944 @cindex build failures, debugging
10945 When defining a new package (@pxref{Defining Packages}), you will
10946 probably find yourself spending some time debugging and tweaking the
10947 build until it succeeds. To do that, you need to operate the build
10948 commands yourself in an environment as close as possible to the one the
10951 To that end, the first thing to do is to use the @option{--keep-failed}
10952 or @option{-K} option of @command{guix build}, which will keep the
10953 failed build tree in @file{/tmp} or whatever directory you specified as
10954 @env{TMPDIR} (@pxref{Common Build Options, @option{--keep-failed}}).
10956 From there on, you can @command{cd} to the failed build tree and source
10957 the @file{environment-variables} file, which contains all the
10958 environment variable definitions that were in place when the build
10959 failed. So let's say you're debugging a build failure in package
10960 @code{foo}; a typical session would look like this:
10963 $ guix build foo -K
10964 @dots{} @i{build fails}
10965 $ cd /tmp/guix-build-foo.drv-0
10966 $ source ./environment-variables
10970 Now, you can invoke commands as if you were the daemon (almost) and
10971 troubleshoot your build process.
10973 Sometimes it happens that, for example, a package's tests pass when you
10974 run them manually but they fail when the daemon runs them. This can
10975 happen because the daemon runs builds in containers where, unlike in our
10976 environment above, network access is missing, @file{/bin/sh} does not
10977 exist, etc. (@pxref{Build Environment Setup}).
10979 In such cases, you may need to run inspect the build process from within
10980 a container similar to the one the build daemon creates:
10983 $ guix build -K foo
10985 $ cd /tmp/guix-build-foo.drv-0
10986 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10987 [env]# source ./environment-variables
10991 Here, @command{guix environment -C} creates a container and spawns a new
10992 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10993 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10994 the container, which you may find handy while debugging. The
10995 @option{--no-grafts} option makes sure we get the exact same
10996 environment, with ungrafted packages (@pxref{Security Updates}, for more
10999 To get closer to a container like that used by the build daemon, we can
11000 remove @file{/bin/sh}:
11006 (Don't worry, this is harmless: this is all happening in the throw-away
11007 container created by @command{guix environment}.)
11009 The @command{strace} command is probably not in the search path, but we
11013 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
11016 In this way, not only you will have reproduced the environment variables
11017 the daemon uses, you will also be running the build process in a container
11018 similar to the one the daemon uses.
11021 @node Invoking guix edit
11022 @section Invoking @command{guix edit}
11024 @cindex @command{guix edit}
11025 @cindex package definition, editing
11026 So many packages, so many source files! The @command{guix edit} command
11027 facilitates the life of users and packagers by pointing their editor at
11028 the source file containing the definition of the specified packages.
11032 guix edit gcc@@4.9 vim
11036 launches the program specified in the @env{VISUAL} or in the
11037 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
11040 If you are using a Guix Git checkout (@pxref{Building from Git}), or
11041 have created your own packages on @env{GUIX_PACKAGE_PATH}
11042 (@pxref{Package Modules}), you will be able to edit the package
11043 recipes. In other cases, you will be able to examine the read-only recipes
11044 for packages currently in the store.
11046 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
11047 @option{--load-path=@var{directory}} (or in short @option{-L
11048 @var{directory}}) allows you to add @var{directory} to the front of the
11049 package module search path and so make your own packages visible.
11051 @node Invoking guix download
11052 @section Invoking @command{guix download}
11054 @cindex @command{guix download}
11055 @cindex downloading package sources
11056 When writing a package definition, developers typically need to download
11057 a source tarball, compute its SHA256 hash, and write that
11058 hash in the package definition (@pxref{Defining Packages}). The
11059 @command{guix download} tool helps with this task: it downloads a file
11060 from the given URI, adds it to the store, and prints both its file name
11061 in the store and its SHA256 hash.
11063 The fact that the downloaded file is added to the store saves bandwidth:
11064 when the developer eventually tries to build the newly defined package
11065 with @command{guix build}, the source tarball will not have to be
11066 downloaded again because it is already in the store. It is also a
11067 convenient way to temporarily stash files, which may be deleted
11068 eventually (@pxref{Invoking guix gc}).
11070 The @command{guix download} command supports the same URIs as used in
11071 package definitions. In particular, it supports @code{mirror://} URIs.
11072 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
11073 Guile bindings for GnuTLS are available in the user's environment; when
11074 they are not available, an error is raised. @xref{Guile Preparations,
11075 how to install the GnuTLS bindings for Guile,, gnutls-guile,
11076 GnuTLS-Guile}, for more information.
11078 @command{guix download} verifies HTTPS server certificates by loading
11079 the certificates of X.509 authorities from the directory pointed to by
11080 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
11081 Certificates}), unless @option{--no-check-certificate} is used.
11083 The following options are available:
11086 @item --hash=@var{algorithm}
11087 @itemx -H @var{algorithm}
11088 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
11089 hash}, for more information.
11091 @item --format=@var{fmt}
11092 @itemx -f @var{fmt}
11093 Write the hash in the format specified by @var{fmt}. For more
11094 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
11096 @item --no-check-certificate
11097 Do not validate the X.509 certificates of HTTPS servers.
11099 When using this option, you have @emph{absolutely no guarantee} that you
11100 are communicating with the authentic server responsible for the given
11101 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
11103 @item --output=@var{file}
11104 @itemx -o @var{file}
11105 Save the downloaded file to @var{file} instead of adding it to the
11109 @node Invoking guix hash
11110 @section Invoking @command{guix hash}
11112 @cindex @command{guix hash}
11113 The @command{guix hash} command computes the hash of a file.
11114 It is primarily a convenience tool for anyone contributing to the
11115 distribution: it computes the cryptographic hash of a file, which can be
11116 used in the definition of a package (@pxref{Defining Packages}).
11118 The general syntax is:
11121 guix hash @var{option} @var{file}
11124 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
11125 hash of data read from standard input. @command{guix hash} has the
11130 @item --hash=@var{algorithm}
11131 @itemx -H @var{algorithm}
11132 Compute a hash using the specified @var{algorithm}, @code{sha256} by
11135 @var{algorithm} must the name of a cryptographic hash algorithm
11136 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
11137 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
11138 Reference Manual}).
11140 @item --format=@var{fmt}
11141 @itemx -f @var{fmt}
11142 Write the hash in the format specified by @var{fmt}.
11144 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
11145 (@code{hex} and @code{hexadecimal} can be used as well).
11147 If the @option{--format} option is not specified, @command{guix hash}
11148 will output the hash in @code{nix-base32}. This representation is used
11149 in the definitions of packages.
11153 Compute the hash on @var{file} recursively.
11155 In this case, the hash is computed on an archive containing @var{file},
11156 including its children if it is a directory. Some of the metadata of
11157 @var{file} is part of the archive; for instance, when @var{file} is a
11158 regular file, the hash is different depending on whether @var{file} is
11159 executable or not. Metadata such as time stamps has no impact on the
11160 hash (@pxref{Invoking guix archive}).
11161 @c FIXME: Replace xref above with xref to an ``Archive'' section when
11164 @item --exclude-vcs
11166 When combined with @option{--recursive}, exclude version control system
11167 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
11170 As an example, here is how you would compute the hash of a Git checkout,
11171 which is useful when using the @code{git-fetch} method (@pxref{origin
11175 $ git clone http://example.org/foo.git
11181 @node Invoking guix import
11182 @section Invoking @command{guix import}
11184 @cindex importing packages
11185 @cindex package import
11186 @cindex package conversion
11187 @cindex Invoking @command{guix import}
11188 The @command{guix import} command is useful for people who would like to
11189 add a package to the distribution with as little work as
11190 possible---a legitimate demand. The command knows of a few
11191 repositories from which it can ``import'' package metadata. The result
11192 is a package definition, or a template thereof, in the format we know
11193 (@pxref{Defining Packages}).
11195 The general syntax is:
11198 guix import @var{importer} @var{options}@dots{}
11201 @var{importer} specifies the source from which to import package
11202 metadata, and @var{options} specifies a package identifier and other
11203 options specific to @var{importer}.
11205 Some of the importers rely on the ability to run the @command{gpgv} command.
11206 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
11209 Currently, the available ``importers'' are:
11213 Import metadata for the given GNU package. This provides a template
11214 for the latest version of that GNU package, including the hash of its
11215 source tarball, and its canonical synopsis and description.
11217 Additional information such as the package dependencies and its
11218 license needs to be figured out manually.
11220 For example, the following command returns a package definition for
11224 guix import gnu hello
11227 Specific command-line options are:
11230 @item --key-download=@var{policy}
11231 As for @command{guix refresh}, specify the policy to handle missing
11232 OpenPGP keys when verifying the package signature. @xref{Invoking guix
11233 refresh, @option{--key-download}}.
11238 Import metadata from the @uref{https://pypi.python.org/, Python Package
11239 Index}. Information is taken from the JSON-formatted description
11240 available at @code{pypi.python.org} and usually includes all the relevant
11241 information, including package dependencies. For maximum efficiency, it
11242 is recommended to install the @command{unzip} utility, so that the
11243 importer can unzip Python wheels and gather data from them.
11245 The command below imports metadata for the @code{itsdangerous} Python
11249 guix import pypi itsdangerous
11255 Traverse the dependency graph of the given upstream package recursively
11256 and generate package expressions for all those packages that are not yet
11262 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
11263 is taken from the JSON-formatted description available at
11264 @code{rubygems.org} and includes most relevant information, including
11265 runtime dependencies. There are some caveats, however. The metadata
11266 doesn't distinguish between synopses and descriptions, so the same string
11267 is used for both fields. Additionally, the details of non-Ruby
11268 dependencies required to build native extensions is unavailable and left
11269 as an exercise to the packager.
11271 The command below imports metadata for the @code{rails} Ruby package:
11274 guix import gem rails
11280 Traverse the dependency graph of the given upstream package recursively
11281 and generate package expressions for all those packages that are not yet
11287 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
11288 Information is taken from the JSON-formatted metadata provided through
11289 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
11290 relevant information, such as module dependencies. License information
11291 should be checked closely. If Perl is available in the store, then the
11292 @code{corelist} utility will be used to filter core modules out of the
11293 list of dependencies.
11295 The command command below imports metadata for the Acme::Boolean Perl
11299 guix import cpan Acme::Boolean
11304 @cindex Bioconductor
11305 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
11306 central repository for the @uref{https://r-project.org, GNU@tie{}R
11307 statistical and graphical environment}.
11309 Information is extracted from the @file{DESCRIPTION} file of the package.
11311 The command command below imports metadata for the Cairo R package:
11314 guix import cran Cairo
11317 When @option{--recursive} is added, the importer will traverse the
11318 dependency graph of the given upstream package recursively and generate
11319 package expressions for all those packages that are not yet in Guix.
11321 When @option{--style=specification} is added, the importer will generate
11322 package definitions whose inputs are package specifications instead of
11323 references to package variables. This is useful when generated package
11324 definitions are to be appended to existing user modules, as the list of
11325 used package modules need not be changed. The default is
11326 @option{--style=variable}.
11328 When @option{--archive=bioconductor} is added, metadata is imported from
11329 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
11330 packages for the analysis and comprehension of high-throughput
11331 genomic data in bioinformatics.
11333 Information is extracted from the @file{DESCRIPTION} file contained in the
11336 The command below imports metadata for the GenomicRanges R package:
11339 guix import cran --archive=bioconductor GenomicRanges
11342 Finally, you can also import R packages that have not yet been published on
11343 CRAN or Bioconductor as long as they are in a git repository. Use
11344 @option{--archive=git} followed by the URL of the git repository:
11347 guix import cran --archive=git https://github.com/immunogenomics/harmony
11353 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
11354 comprehensive TeX archive network for TeX packages that are part of the
11355 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
11357 Information about the package is obtained through the XML API provided
11358 by CTAN, while the source code is downloaded from the SVN repository of
11359 the Tex Live project. This is done because the CTAN does not keep
11360 versioned archives.
11362 The command command below imports metadata for the @code{fontspec}
11366 guix import texlive fontspec
11369 When @option{--archive=@var{directory}} is added, the source code is
11370 downloaded not from the @file{latex} sub-directory of the
11371 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
11372 the specified sibling @var{directory} under the same root.
11374 The command below imports metadata for the @code{ifxetex} package from
11375 CTAN while fetching the sources from the directory
11376 @file{texmf/source/generic}:
11379 guix import texlive --archive=generic ifxetex
11383 @cindex JSON, import
11384 Import package metadata from a local JSON file. Consider the following
11385 example package definition in JSON format:
11391 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11392 "build-system": "gnu",
11393 "home-page": "https://www.gnu.org/software/hello/",
11394 "synopsis": "Hello, GNU world: An example GNU package",
11395 "description": "GNU Hello prints a greeting.",
11396 "license": "GPL-3.0+",
11397 "native-inputs": ["gettext"]
11401 The field names are the same as for the @code{<package>} record
11402 (@xref{Defining Packages}). References to other packages are provided
11403 as JSON lists of quoted package specification strings such as
11404 @code{guile} or @code{guile@@2.0}.
11406 The importer also supports a more explicit source definition using the
11407 common fields for @code{<origin>} records:
11413 "method": "url-fetch",
11414 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11416 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11423 The command below reads metadata from the JSON file @code{hello.json}
11424 and outputs a package expression:
11427 guix import json hello.json
11432 Import metadata from the Haskell community's central package archive
11433 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11434 Cabal files and includes all the relevant information, including package
11437 Specific command-line options are:
11442 Read a Cabal file from standard input.
11443 @item --no-test-dependencies
11445 Do not include dependencies required only by the test suites.
11446 @item --cabal-environment=@var{alist}
11447 @itemx -e @var{alist}
11448 @var{alist} is a Scheme alist defining the environment in which the
11449 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11450 @code{arch}, @code{impl} and a string representing the name of a flag.
11451 The value associated with a flag has to be either the symbol
11452 @code{true} or @code{false}. The value associated with other keys
11453 has to conform to the Cabal file format definition. The default value
11454 associated with the keys @code{os}, @code{arch} and @code{impl} is
11455 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11458 Traverse the dependency graph of the given upstream package recursively
11459 and generate package expressions for all those packages that are not yet
11463 The command below imports metadata for the latest version of the
11464 HTTP Haskell package without including test dependencies and
11465 specifying the value of the flag @samp{network-uri} as @code{false}:
11468 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11471 A specific package version may optionally be specified by following the
11472 package name by an at-sign and a version number as in the following example:
11475 guix import hackage mtl@@2.1.3.1
11480 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11481 It takes a package name, looks up the package version included in a
11482 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11483 release and uses the @code{hackage} importer to retrieve its metadata.
11484 Note that it is up to you to select an LTS release compatible with the
11485 GHC compiler used by Guix.
11487 Specific command-line options are:
11490 @item --no-test-dependencies
11492 Do not include dependencies required only by the test suites.
11493 @item --lts-version=@var{version}
11494 @itemx -l @var{version}
11495 @var{version} is the desired LTS release version. If omitted the latest
11499 Traverse the dependency graph of the given upstream package recursively
11500 and generate package expressions for all those packages that are not yet
11504 The command below imports metadata for the HTTP Haskell package
11505 included in the LTS Stackage release version 7.18:
11508 guix import stackage --lts-version=7.18 HTTP
11513 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11514 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11516 Specific command-line options are:
11519 @item --archive=@var{repo}
11520 @itemx -a @var{repo}
11521 @var{repo} identifies the archive repository from which to retrieve the
11522 information. Currently the supported repositories and their identifiers
11526 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11527 identifier. This is the default.
11529 Packages from @code{elpa.gnu.org} are signed with one of the keys
11530 contained in the GnuPG keyring at
11531 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11532 @code{emacs} package (@pxref{Package Installation, ELPA package
11533 signatures,, emacs, The GNU Emacs Manual}).
11536 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11537 @code{melpa-stable} identifier.
11540 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11546 Traverse the dependency graph of the given upstream package recursively
11547 and generate package expressions for all those packages that are not yet
11553 Import metadata from the crates.io Rust package repository
11554 @uref{https://crates.io, crates.io}, as in this example:
11557 guix import crate blake2-rfc
11560 The crate importer also allows you to specify a version string:
11563 guix import crate constant-time-eq@@0.1.0
11566 Additional options include:
11571 Traverse the dependency graph of the given upstream package recursively
11572 and generate package expressions for all those packages that are not yet
11579 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11580 repository used by the OCaml community.
11582 Additional options include:
11587 Traverse the dependency graph of the given upstream package recursively
11588 and generate package expressions for all those packages that are not yet
11591 Select the given repository (a repository name). Possible values include:
11593 @item @code{opam}, the default opam repository,
11594 @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
11595 @item @code{coq-core-dev}, the repository that contains development versions of coq,
11596 @item @code{coq-extra-dev}, the repository that contains development versions
11603 Import metadata for a Go module using
11604 @uref{https://proxy.golang.org, proxy.golang.org}.
11607 guix import go gopkg.in/yaml.v2
11610 It is possible to use a package specification with a @code{@@VERSION}
11611 suffix to import a specific version.
11613 Additional options include:
11618 Traverse the dependency graph of the given upstream package recursively
11619 and generate package expressions for all those packages that are not yet
11621 @item --pin-versions
11622 When using this option, the importer preserves the exact versions of the
11623 Go modules dependencies instead of using their latest available
11624 versions. This can be useful when attempting to import packages that
11625 recursively depend on former versions of themselves to build. When
11626 using this mode, the symbol of the package is made by appending the
11627 version to its name, so that multiple versions of the same package can
11633 Import metadata for @uref{https://wiki.call-cc.org/eggs, CHICKEN eggs}.
11634 The information is taken from @file{PACKAGE.egg} files found in the
11635 @uref{git://code.call-cc.org/eggs-5-latest, eggs-5-latest} Git
11636 repository. However, it does not provide all the information that we
11637 need, there is no ``description'' field, and the licenses used are not
11638 always precise (BSD is often used instead of BSD-N).
11641 guix import egg sourcehut
11644 Additional options include:
11648 Traverse the dependency graph of the given upstream package recursively
11649 and generate package expressions for all those packages that are not yet
11654 The structure of the @command{guix import} code is modular. It would be
11655 useful to have more importers for other package formats, and your help
11656 is welcome here (@pxref{Contributing}).
11658 @node Invoking guix refresh
11659 @section Invoking @command{guix refresh}
11661 @cindex @command {guix refresh}
11662 The primary audience of the @command{guix refresh} command is packagers.
11663 As a user, you may be interested in the @option{--with-latest} option,
11664 which can bring you package update superpowers built upon @command{guix
11665 refresh} (@pxref{Package Transformation Options,
11666 @option{--with-latest}}). By default, @command{guix refresh} reports
11667 any packages provided by the distribution that are outdated compared to
11668 the latest upstream version, like this:
11672 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11673 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11676 Alternatively, one can specify packages to consider, in which case a
11677 warning is emitted for packages that lack an updater:
11680 $ guix refresh coreutils guile guile-ssh
11681 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11682 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11685 @command{guix refresh} browses the upstream repository of each package and determines
11686 the highest version number of the releases therein. The command
11687 knows how to update specific types of packages: GNU packages, ELPA
11688 packages, etc.---see the documentation for @option{--type} below. There
11689 are many packages, though, for which it lacks a method to determine
11690 whether a new upstream release is available. However, the mechanism is
11691 extensible, so feel free to get in touch with us to add a new method!
11696 Consider the packages specified, and all the packages upon which they depend.
11699 $ guix refresh --recursive coreutils
11700 gnu/packages/acl.scm:40:13: acl would be upgraded from 2.2.53 to 2.3.1
11701 gnu/packages/m4.scm:30:12: 1.4.18 is already the latest version of m4
11702 gnu/packages/xml.scm:68:2: warning: no updater for expat
11703 gnu/packages/multiprecision.scm:40:12: 6.1.2 is already the latest version of gmp
11709 Sometimes the upstream name differs from the package name used in Guix,
11710 and @command{guix refresh} needs a little help. Most updaters honor the
11711 @code{upstream-name} property in package definitions, which can be used
11715 (define-public network-manager
11717 (name "network-manager")
11719 (properties '((upstream-name . "NetworkManager")))))
11722 When passed @option{--update}, it modifies distribution source files to
11723 update the version numbers and source tarball hashes of those package
11724 recipes (@pxref{Defining Packages}). This is achieved by downloading
11725 each package's latest source tarball and its associated OpenPGP
11726 signature, authenticating the downloaded tarball against its signature
11727 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11728 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11731 key used to sign the tarball is missing from the user's keyring, an
11732 attempt is made to automatically retrieve it from a public key server;
11733 when this is successful, the key is added to the user's keyring; otherwise,
11734 @command{guix refresh} reports an error.
11736 The following options are supported:
11740 @item --expression=@var{expr}
11741 @itemx -e @var{expr}
11742 Consider the package @var{expr} evaluates to.
11744 This is useful to precisely refer to a package, as in this example:
11747 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11750 This command lists the dependents of the ``final'' libc (essentially all
11755 Update distribution source files (package recipes) in place. This is
11756 usually run from a checkout of the Guix source tree (@pxref{Running
11757 Guix Before It Is Installed}):
11760 $ ./pre-inst-env guix refresh -s non-core -u
11763 @xref{Defining Packages}, for more information on package definitions.
11765 @item --select=[@var{subset}]
11766 @itemx -s @var{subset}
11767 Select all the packages in @var{subset}, one of @code{core} or
11770 The @code{core} subset refers to all the packages at the core of the
11771 distribution---i.e., packages that are used to build ``everything
11772 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11773 changing one of these packages in the distribution entails a rebuild of
11774 all the others. Thus, such updates are an inconvenience to users in
11775 terms of build time or bandwidth used to achieve the upgrade.
11777 The @code{non-core} subset refers to the remaining packages. It is
11778 typically useful in cases where an update of the core packages would be
11781 @item --manifest=@var{file}
11782 @itemx -m @var{file}
11783 Select all the packages from the manifest in @var{file}. This is useful to
11784 check if any packages of the user manifest can be updated.
11786 @item --type=@var{updater}
11787 @itemx -t @var{updater}
11788 Select only packages handled by @var{updater} (may be a comma-separated
11789 list of updaters). Currently, @var{updater} may be one of:
11793 the updater for GNU packages;
11795 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11797 the updater for packages hosted at @uref{https://sourceforge.net, SourceForge};
11799 the updater for GNOME packages;
11801 the updater for KDE packages;
11803 the updater for X.org packages;
11805 the updater for packages hosted on kernel.org;
11807 the updater for @uref{https://wiki.call-cc.org/eggs/, Egg} packages;
11809 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11811 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11813 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11815 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11817 the updater for @uref{https://pypi.python.org, PyPI} packages.
11819 the updater for @uref{https://rubygems.org, RubyGems} packages.
11821 the updater for @uref{https://github.com, GitHub} packages.
11823 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11825 the updater for @uref{https://www.stackage.org, Stackage} packages.
11827 the updater for @uref{https://crates.io, Crates} packages.
11829 the updater for @uref{https://launchpad.net, Launchpad} packages.
11831 a generic updater that crawls the HTML page where the source tarball of
11832 the package is hosted, when applicable.
11835 For instance, the following command only checks for updates of Emacs
11836 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11839 $ guix refresh --type=elpa,cran
11840 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11841 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11844 @item --list-updaters
11846 List available updaters and exit (see @option{--type} above).
11848 For each updater, display the fraction of packages it covers; at the
11849 end, display the fraction of packages covered by all these updaters.
11852 In addition, @command{guix refresh} can be passed one or more package
11853 names, as in this example:
11856 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11860 The command above specifically updates the @code{emacs} and
11861 @code{idutils} packages. The @option{--select} option would have no
11862 effect in this case. You might also want to update definitions that
11863 correspond to the packages installed in your profile:
11866 $ ./pre-inst-env guix refresh -u \
11867 $(guix package --list-installed | cut -f1)
11870 When considering whether to upgrade a package, it is sometimes
11871 convenient to know which packages would be affected by the upgrade and
11872 should be checked for compatibility. For this the following option may
11873 be used when passing @command{guix refresh} one or more package names:
11877 @item --list-dependent
11879 List top-level dependent packages that would need to be rebuilt as a
11880 result of upgrading one or more packages.
11882 @xref{Invoking guix graph, the @code{reverse-package} type of
11883 @command{guix graph}}, for information on how to visualize the list of
11884 dependents of a package.
11888 Be aware that the @option{--list-dependent} option only
11889 @emph{approximates} the rebuilds that would be required as a result of
11890 an upgrade. More rebuilds might be required under some circumstances.
11893 $ guix refresh --list-dependent flex
11894 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11895 hop@@2.4.0 emacs-geiser@@0.13 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11898 The command above lists a set of packages that could be built to check
11899 for compatibility with an upgraded @code{flex} package.
11903 @item --list-transitive
11904 List all the packages which one or more packages depend upon.
11907 $ guix refresh --list-transitive flex
11908 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11909 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{}
11914 The command above lists a set of packages which, when changed, would cause
11915 @code{flex} to be rebuilt.
11917 The following options can be used to customize GnuPG operation:
11921 @item --gpg=@var{command}
11922 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11923 for in @code{$PATH}.
11925 @item --keyring=@var{file}
11926 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11927 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11928 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11929 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11930 information on a tool to manipulate keybox files).
11932 When this option is omitted, @command{guix refresh} uses
11933 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11934 signing keys. OpenPGP signatures are checked against keys from this keyring;
11935 missing keys are downloaded to this keyring as well (see
11936 @option{--key-download} below).
11938 You can export keys from your default GPG keyring into a keybox file using
11939 commands like this one:
11942 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11945 Likewise, you can fetch keys to a specific keybox file like this:
11948 gpg --no-default-keyring --keyring mykeyring.kbx \
11949 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11952 @xref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11953 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11955 @item --key-download=@var{policy}
11956 Handle missing OpenPGP keys according to @var{policy}, which may be one
11961 Always download missing OpenPGP keys from the key server, and add them
11962 to the user's GnuPG keyring.
11965 Never try to download missing OpenPGP keys. Instead just bail out.
11968 When a package signed with an unknown OpenPGP key is encountered, ask
11969 the user whether to download it or not. This is the default behavior.
11972 @item --key-server=@var{host}
11973 Use @var{host} as the OpenPGP key server when importing a public key.
11975 @item --load-path=@var{directory}
11976 Add @var{directory} to the front of the package module search path
11977 (@pxref{Package Modules}).
11979 This allows users to define their own packages and make them visible to
11980 the command-line tools.
11984 The @code{github} updater uses the
11985 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11986 releases. When used repeatedly e.g.@: when refreshing all packages,
11987 GitHub will eventually refuse to answer any further API requests. By
11988 default 60 API requests per hour are allowed, and a full refresh on all
11989 GitHub packages in Guix requires more than this. Authentication with
11990 GitHub through the use of an API token alleviates these limits. To use
11991 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11992 token procured from @uref{https://github.com/settings/tokens} or
11996 @node Invoking guix lint
11997 @section Invoking @command{guix lint}
11999 @cindex @command{guix lint}
12000 @cindex package, checking for errors
12001 The @command{guix lint} command is meant to help package developers avoid
12002 common errors and use a consistent style. It runs a number of checks on
12003 a given set of packages in order to find common mistakes in their
12004 definitions. Available @dfn{checkers} include (see
12005 @option{--list-checkers} for a complete list):
12010 Validate certain typographical and stylistic rules about package
12011 descriptions and synopses.
12013 @item inputs-should-be-native
12014 Identify inputs that should most likely be native inputs.
12020 @itemx source-file-name
12021 Probe @code{home-page} and @code{source} URLs and report those that are
12022 invalid. Suggest a @code{mirror://} URL when applicable. If the
12023 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
12024 URL@. Check that the source file name is meaningful, e.g.@: is not just a
12025 version number or ``git-checkout'', without a declared @code{file-name}
12026 (@pxref{origin Reference}).
12028 @item source-unstable-tarball
12029 Parse the @code{source} URL to determine if a tarball from GitHub is
12030 autogenerated or if it is a release tarball. Unfortunately GitHub's
12031 autogenerated tarballs are sometimes regenerated.
12034 Check that the derivation of the given packages can be successfully
12035 computed for all the supported systems (@pxref{Derivations}).
12037 @item profile-collisions
12038 Check whether installing the given packages in a profile would lead to
12039 collisions. Collisions occur when several packages with the same name
12040 but a different version or a different store file name are propagated.
12041 @xref{package Reference, @code{propagated-inputs}}, for more information
12042 on propagated inputs.
12045 @cindex Software Heritage, source code archive
12046 @cindex archival of source code, Software Heritage
12047 Checks whether the package's source code is archived at
12048 @uref{https://www.softwareheritage.org, Software Heritage}.
12050 When the source code that is not archived comes from a version-control system
12051 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
12052 ``save'' request so that it eventually archives it. This ensures that the
12053 source will remain available in the long term, and that Guix can fall back to
12054 Software Heritage should the source code disappear from its original host.
12055 The status of recent ``save'' requests can be
12056 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
12058 When source code is a tarball obtained with @code{url-fetch}, simply print a
12059 message when it is not archived. As of this writing, Software Heritage does
12060 not allow requests to save arbitrary tarballs; we are working on ways to
12061 ensure that non-VCS source code is also archived.
12064 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
12065 request rate per IP address}. When the limit is reached, @command{guix lint}
12066 prints a message and the @code{archival} checker stops doing anything until
12067 that limit has been reset.
12070 @cindex security vulnerabilities
12071 @cindex CVE, Common Vulnerabilities and Exposures
12072 Report known vulnerabilities found in the Common Vulnerabilities and
12073 Exposures (CVE) databases of the current and past year
12074 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
12077 To view information about a particular vulnerability, visit pages such as:
12081 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
12083 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
12087 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
12088 @code{CVE-2015-7554}.
12090 Package developers can specify in package recipes the
12091 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
12092 name and version of the package when they differ from the name or version
12093 that Guix uses, as in this example:
12099 ;; CPE calls this package "grub2".
12100 (properties '((cpe-name . "grub2")
12101 (cpe-version . "2.3"))))
12104 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
12105 Some entries in the CVE database do not specify which version of a
12106 package they apply to, and would thus ``stick around'' forever. Package
12107 developers who found CVE alerts and verified they can be ignored can
12108 declare them as in this example:
12114 ;; These CVEs no longer apply and can be safely ignored.
12115 (properties `((lint-hidden-cve . ("CVE-2011-0433"
12118 "CVE-2011-5244")))))
12122 Warn about obvious source code formatting issues: trailing white space,
12123 use of tabulations, etc.
12126 The general syntax is:
12129 guix lint @var{options} @var{package}@dots{}
12132 If no package is given on the command line, then all packages are checked.
12133 The @var{options} may be zero or more of the following:
12136 @item --list-checkers
12138 List and describe all the available checkers that will be run on packages
12143 Only enable the checkers specified in a comma-separated list using the
12144 names returned by @option{--list-checkers}.
12148 Only disable the checkers specified in a comma-separated list using the
12149 names returned by @option{--list-checkers}.
12153 Only enable the checkers that do not depend on Internet access.
12155 @item --load-path=@var{directory}
12156 @itemx -L @var{directory}
12157 Add @var{directory} to the front of the package module search path
12158 (@pxref{Package Modules}).
12160 This allows users to define their own packages and make them visible to
12161 the command-line tools.
12165 @node Invoking guix size
12166 @section Invoking @command{guix size}
12169 @cindex package size
12171 @cindex @command{guix size}
12172 The @command{guix size} command helps package developers profile the
12173 disk usage of packages. It is easy to overlook the impact of an
12174 additional dependency added to a package, or the impact of using a
12175 single output for a package that could easily be split (@pxref{Packages
12176 with Multiple Outputs}). Such are the typical issues that
12177 @command{guix size} can highlight.
12179 The command can be passed one or more package specifications
12180 such as @code{gcc@@4.8}
12181 or @code{guile:debug}, or a file name in the store. Consider this
12185 $ guix size coreutils
12186 store item total self
12187 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
12188 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
12189 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
12190 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
12191 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
12192 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
12193 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
12194 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
12199 The store items listed here constitute the @dfn{transitive closure} of
12200 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
12201 would be returned by:
12204 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
12207 Here the output shows three columns next to store items. The first column,
12208 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
12209 the store item---that is, its own size plus the size of all its
12210 dependencies. The next column, labeled ``self'', shows the size of the
12211 item itself. The last column shows the ratio of the size of the item
12212 itself to the space occupied by all the items listed here.
12214 In this example, we see that the closure of Coreutils weighs in at
12215 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
12216 libraries. (That libc and GCC's libraries represent a large fraction of
12217 the closure is not a problem @i{per se} because they are always available
12218 on the system anyway.)
12220 Since the command also accepts store file names, assessing the size of
12221 a build result is straightforward:
12224 guix size $(guix system build config.scm)
12227 When the package(s) passed to @command{guix size} are available in the
12228 store@footnote{More precisely, @command{guix size} looks for the
12229 @emph{ungrafted} variant of the given package(s), as returned by
12230 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
12231 for information on grafts.}, @command{guix size} queries the daemon to determine its
12232 dependencies, and measures its size in the store, similar to @command{du
12233 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
12236 When the given packages are @emph{not} in the store, @command{guix size}
12237 reports information based on the available substitutes
12238 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
12239 store items that are not even on disk, only available remotely.
12241 You can also specify several package names:
12244 $ guix size coreutils grep sed bash
12245 store item total self
12246 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
12247 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
12248 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
12249 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
12255 In this example we see that the combination of the four packages takes
12256 102.3@tie{}MiB in total, which is much less than the sum of each closure
12257 since they have a lot of dependencies in common.
12259 When looking at the profile returned by @command{guix size}, you may
12260 find yourself wondering why a given package shows up in the profile at
12261 all. To understand it, you can use @command{guix graph --path -t
12262 references} to display the shortest path between the two packages
12263 (@pxref{Invoking guix graph}).
12265 The available options are:
12269 @item --substitute-urls=@var{urls}
12270 Use substitute information from @var{urls}.
12271 @xref{client-substitute-urls, the same option for @code{guix build}}.
12273 @item --sort=@var{key}
12274 Sort lines according to @var{key}, one of the following options:
12278 the size of each item (the default);
12280 the total size of the item's closure.
12283 @item --map-file=@var{file}
12284 Write a graphical map of disk usage in PNG format to @var{file}.
12286 For the example above, the map looks like this:
12288 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
12289 produced by @command{guix size}}
12291 This option requires that
12292 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
12293 installed and visible in Guile's module search path. When that is not
12294 the case, @command{guix size} fails as it tries to load it.
12296 @item --system=@var{system}
12297 @itemx -s @var{system}
12298 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
12300 @item --load-path=@var{directory}
12301 @itemx -L @var{directory}
12302 Add @var{directory} to the front of the package module search path
12303 (@pxref{Package Modules}).
12305 This allows users to define their own packages and make them visible to
12306 the command-line tools.
12309 @node Invoking guix graph
12310 @section Invoking @command{guix graph}
12313 @cindex @command{guix graph}
12314 @cindex package dependencies
12315 Packages and their dependencies form a @dfn{graph}, specifically a
12316 directed acyclic graph (DAG). It can quickly become difficult to have a
12317 mental model of the package DAG, so the @command{guix graph} command
12318 provides a visual representation of the DAG@. By default,
12319 @command{guix graph} emits a DAG representation in the input format of
12320 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
12321 directly to the @command{dot} command of Graphviz. It can also emit an
12322 HTML page with embedded JavaScript code to display a ``chord diagram''
12323 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
12324 emit Cypher queries to construct a graph in a graph database supporting
12325 the @uref{https://www.opencypher.org/, openCypher} query language. With
12326 @option{--path}, it simply displays the shortest path between two
12327 packages. The general syntax is:
12330 guix graph @var{options} @var{package}@dots{}
12333 For example, the following command generates a PDF file representing the
12334 package DAG for the GNU@tie{}Core Utilities, showing its build-time
12338 guix graph coreutils | dot -Tpdf > dag.pdf
12341 The output looks like this:
12343 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
12345 Nice little graph, no?
12347 You may find it more pleasant to navigate the graph interactively with
12348 @command{xdot} (from the @code{xdot} package):
12351 guix graph coreutils | xdot -
12354 But there is more than one graph! The one above is concise: it is the
12355 graph of package objects, omitting implicit inputs such as GCC, libc,
12356 grep, etc. It is often useful to have such a concise graph, but
12357 sometimes one may want to see more details. @command{guix graph} supports
12358 several types of graphs, allowing you to choose the level of detail:
12362 This is the default type used in the example above. It shows the DAG of
12363 package objects, excluding implicit dependencies. It is concise, but
12364 filters out many details.
12366 @item reverse-package
12367 This shows the @emph{reverse} DAG of packages. For example:
12370 guix graph --type=reverse-package ocaml
12373 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12374 you are also interested in cases where OCaml is an implicit dependency, see
12375 @code{reverse-bag} below).
12377 Note that for core packages this can yield huge graphs. If all you want
12378 is to know the number of packages that depend on a given package, use
12379 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12380 @option{--list-dependent}}).
12383 This is the package DAG, @emph{including} implicit inputs.
12385 For instance, the following command:
12388 guix graph --type=bag-emerged coreutils
12391 ...@: yields this bigger graph:
12393 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12395 At the bottom of the graph, we see all the implicit inputs of
12396 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12398 Now, note that the dependencies of these implicit inputs---that is, the
12399 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12400 here, for conciseness.
12403 Similar to @code{bag-emerged}, but this time including all the bootstrap
12406 @item bag-with-origins
12407 Similar to @code{bag}, but also showing origins and their dependencies.
12410 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12411 it also takes implicit dependencies into account. For example:
12414 guix graph -t reverse-bag dune
12418 ...@: yields the graph of all packages that depend on Dune, directly or
12419 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12420 @i{via} @code{dune-build-system}, this shows a large number of packages,
12421 whereas @code{reverse-package} would show very few if any.
12424 This is the most detailed representation: It shows the DAG of
12425 derivations (@pxref{Derivations}) and plain store items. Compared to
12426 the above representation, many additional nodes are visible, including
12427 build scripts, patches, Guile modules, etc.
12429 For this type of graph, it is also possible to pass a @file{.drv} file
12430 name instead of a package name, as in:
12433 guix graph -t derivation $(guix system build -d my-config.scm)
12437 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12438 For example, the following command shows the graph for the package
12439 module that defines the @code{guile} package:
12442 guix graph -t module guile | xdot -
12446 All the types above correspond to @emph{build-time dependencies}. The
12447 following graph type represents the @emph{run-time dependencies}:
12451 This is the graph of @dfn{references} of a package output, as returned
12452 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12454 If the given package output is not available in the store, @command{guix
12455 graph} attempts to obtain dependency information from substitutes.
12457 Here you can also pass a store file name instead of a package name. For
12458 example, the command below produces the reference graph of your profile
12459 (which can be big!):
12462 guix graph -t references $(readlink -f ~/.guix-profile)
12466 This is the graph of the @dfn{referrers} of a store item, as returned by
12467 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12469 This relies exclusively on local information from your store. For
12470 instance, let us suppose that the current Inkscape is available in 10
12471 profiles on your machine; @command{guix graph -t referrers inkscape}
12472 will show a graph rooted at Inkscape and with those 10 profiles linked
12475 It can help determine what is preventing a store item from being garbage
12480 @cindex shortest path, between packages
12481 Often, the graph of the package you are interested in does not fit on
12482 your screen, and anyway all you want to know is @emph{why} that package
12483 actually depends on some seemingly unrelated package. The
12484 @option{--path} option instructs @command{guix graph} to display the
12485 shortest path between two packages (or derivations, or store items,
12489 $ guix graph --path emacs libunistring
12492 libunistring@@0.9.10
12493 $ guix graph --path -t derivation emacs libunistring
12494 /gnu/store/@dots{}-emacs-26.3.drv
12495 /gnu/store/@dots{}-mailutils-3.9.drv
12496 /gnu/store/@dots{}-libunistring-0.9.10.drv
12497 $ guix graph --path -t references emacs libunistring
12498 /gnu/store/@dots{}-emacs-26.3
12499 /gnu/store/@dots{}-libidn2-2.2.0
12500 /gnu/store/@dots{}-libunistring-0.9.10
12503 The available options are the following:
12506 @item --type=@var{type}
12507 @itemx -t @var{type}
12508 Produce a graph output of @var{type}, where @var{type} must be one of
12509 the values listed above.
12512 List the supported graph types.
12514 @item --backend=@var{backend}
12515 @itemx -b @var{backend}
12516 Produce a graph using the selected @var{backend}.
12518 @item --list-backends
12519 List the supported graph backends.
12521 Currently, the available backends are Graphviz and d3.js.
12524 Display the shortest path between two nodes of the type specified by
12525 @option{--type}. The example below shows the shortest path between
12526 @code{libreoffice} and @code{llvm} according to the references of
12527 @code{libreoffice}:
12530 $ guix graph --path -t references libreoffice llvm
12531 /gnu/store/@dots{}-libreoffice-6.4.2.2
12532 /gnu/store/@dots{}-libepoxy-1.5.4
12533 /gnu/store/@dots{}-mesa-19.3.4
12534 /gnu/store/@dots{}-llvm-9.0.1
12537 @item --expression=@var{expr}
12538 @itemx -e @var{expr}
12539 Consider the package @var{expr} evaluates to.
12541 This is useful to precisely refer to a package, as in this example:
12544 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12547 @item --system=@var{system}
12548 @itemx -s @var{system}
12549 Display the graph for @var{system}---e.g., @code{i686-linux}.
12551 The package dependency graph is largely architecture-independent, but there
12552 are some architecture-dependent bits that this option allows you to visualize.
12554 @item --load-path=@var{directory}
12555 @itemx -L @var{directory}
12556 Add @var{directory} to the front of the package module search path
12557 (@pxref{Package Modules}).
12559 This allows users to define their own packages and make them visible to
12560 the command-line tools.
12563 On top of that, @command{guix graph} supports all the usual package
12564 transformation options (@pxref{Package Transformation Options}). This
12565 makes it easy to view the effect of a graph-rewriting transformation
12566 such as @option{--with-input}. For example, the command below outputs
12567 the graph of @code{git} once @code{openssl} has been replaced by
12568 @code{libressl} everywhere in the graph:
12571 guix graph git --with-input=openssl=libressl
12574 So many possibilities, so much fun!
12576 @node Invoking guix publish
12577 @section Invoking @command{guix publish}
12579 @cindex @command{guix publish}
12580 The purpose of @command{guix publish} is to enable users to easily share
12581 their store with others, who can then use it as a substitute server
12582 (@pxref{Substitutes}).
12584 When @command{guix publish} runs, it spawns an HTTP server which allows
12585 anyone with network access to obtain substitutes from it. This means
12586 that any machine running Guix can also act as if it were a build farm,
12587 since the HTTP interface is compatible with Cuirass, the software behind
12588 the @code{@value{SUBSTITUTE-SERVER-1}} build farm.
12590 For security, each substitute is signed, allowing recipients to check
12591 their authenticity and integrity (@pxref{Substitutes}). Because
12592 @command{guix publish} uses the signing key of the system, which is only
12593 readable by the system administrator, it must be started as root; the
12594 @option{--user} option makes it drop root privileges early on.
12596 The signing key pair must be generated before @command{guix publish} is
12597 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12600 When the @option{--advertise} option is passed, the server advertises
12601 its availability on the local network using multicast DNS (mDNS) and DNS
12602 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12603 guile-avahi, Using Avahi in Guile Scheme Programs}).
12605 The general syntax is:
12608 guix publish @var{options}@dots{}
12611 Running @command{guix publish} without any additional arguments will
12612 spawn an HTTP server on port 8080:
12618 Once a publishing server has been authorized, the daemon may download
12619 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12621 By default, @command{guix publish} compresses archives on the fly as it
12622 serves them. This ``on-the-fly'' mode is convenient in that it requires
12623 no setup and is immediately available. However, when serving lots of
12624 clients, we recommend using the @option{--cache} option, which enables
12625 caching of the archives before they are sent to clients---see below for
12626 details. The @command{guix weather} command provides a handy way to
12627 check what a server provides (@pxref{Invoking guix weather}).
12629 As a bonus, @command{guix publish} also serves as a content-addressed
12630 mirror for source files referenced in @code{origin} records
12631 (@pxref{origin Reference}). For instance, assuming @command{guix
12632 publish} is running on @code{example.org}, the following URL returns the
12633 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12634 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12637 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12640 Obviously, these URLs only work for files that are in the store; in
12641 other cases, they return 404 (``Not Found'').
12643 @cindex build logs, publication
12644 Build logs are available from @code{/log} URLs like:
12647 http://example.org/log/gwspk@dots{}-guile-2.2.3
12651 When @command{guix-daemon} is configured to save compressed build logs,
12652 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12653 URLs return the compressed log as-is, with an appropriate
12654 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12655 running @command{guix-daemon} with @option{--log-compression=gzip} since
12656 Web browsers can automatically decompress it, which is not the case with
12659 The following options are available:
12662 @item --port=@var{port}
12663 @itemx -p @var{port}
12664 Listen for HTTP requests on @var{port}.
12666 @item --listen=@var{host}
12667 Listen on the network interface for @var{host}. The default is to
12668 accept connections from any interface.
12670 @item --user=@var{user}
12671 @itemx -u @var{user}
12672 Change privileges to @var{user} as soon as possible---i.e., once the
12673 server socket is open and the signing key has been read.
12675 @item --compression[=@var{method}[:@var{level}]]
12676 @itemx -C [@var{method}[:@var{level}]]
12677 Compress data using the given @var{method} and @var{level}. @var{method} is
12678 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
12679 omitted, @code{gzip} is used.
12681 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12682 to different compression levels: 1 is the fastest, and 9 is the best
12683 (CPU-intensive). The default is 3.
12685 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
12686 small increase in CPU usage; see
12687 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
12688 Web page}. However, @code{lzip} achieves low decompression throughput
12689 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
12690 bottleneck for someone who downloads over a fast network connection.
12692 The compression ratio of @code{zstd} is between that of @code{lzip} and
12693 that of @code{gzip}; its main advantage is a
12694 @uref{https://facebook.github.io/zstd/,high decompression speed}.
12696 Unless @option{--cache} is used, compression occurs on the fly and
12697 the compressed streams are not
12698 cached. Thus, to reduce load on the machine that runs @command{guix
12699 publish}, it may be a good idea to choose a low compression level, to
12700 run @command{guix publish} behind a caching proxy, or to use
12701 @option{--cache}. Using @option{--cache} has the advantage that it
12702 allows @command{guix publish} to add @code{Content-Length} HTTP header
12705 This option can be repeated, in which case every substitute gets compressed
12706 using all the selected methods, and all of them are advertised. This is
12707 useful when users may not support all the compression methods: they can select
12708 the one they support.
12710 @item --cache=@var{directory}
12711 @itemx -c @var{directory}
12712 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12713 and only serve archives that are in cache.
12715 When this option is omitted, archives and meta-data are created
12716 on-the-fly. This can reduce the available bandwidth, especially when
12717 compression is enabled, since this may become CPU-bound. Another
12718 drawback of the default mode is that the length of archives is not known
12719 in advance, so @command{guix publish} does not add a
12720 @code{Content-Length} HTTP header to its responses, which in turn
12721 prevents clients from knowing the amount of data being downloaded.
12723 Conversely, when @option{--cache} is used, the first request for a store
12724 item (@i{via} a @code{.narinfo} URL) triggers a
12725 background process to @dfn{bake} the archive---computing its
12726 @code{.narinfo} and compressing the archive, if needed. Once the
12727 archive is cached in @var{directory}, subsequent requests succeed and
12728 are served directly from the cache, which guarantees that clients get
12729 the best possible bandwidth.
12731 That first @code{.narinfo} request nonetheless returns 200, provided the
12732 requested store item is ``small enough'', below the cache bypass
12733 threshold---see @option{--cache-bypass-threshold} below. That way,
12734 clients do not have to wait until the archive is baked. For larger
12735 store items, the first @code{.narinfo} request returns 404, meaning that
12736 clients have to wait until the archive is baked.
12738 The ``baking'' process is performed by worker threads. By default, one
12739 thread per CPU core is created, but this can be customized. See
12740 @option{--workers} below.
12742 When @option{--ttl} is used, cached entries are automatically deleted
12743 when they have expired.
12745 @item --workers=@var{N}
12746 When @option{--cache} is used, request the allocation of @var{N} worker
12747 threads to ``bake'' archives.
12749 @item --ttl=@var{ttl}
12750 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12751 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12752 days, @code{1m} means 1 month, and so on.
12754 This allows the user's Guix to keep substitute information in cache for
12755 @var{ttl}. However, note that @code{guix publish} does not itself
12756 guarantee that the store items it provides will indeed remain available
12757 for as long as @var{ttl}.
12759 Additionally, when @option{--cache} is used, cached entries that have
12760 not been accessed for @var{ttl} and that no longer have a corresponding
12761 item in the store, may be deleted.
12763 @item --negative-ttl=@var{ttl}
12764 Similarly produce @code{Cache-Control} HTTP headers to advertise the
12765 time-to-live (TTL) of @emph{negative} lookups---missing store items, for
12766 which the HTTP 404 code is returned. By default, no negative TTL is
12769 This parameter can help adjust server load and substitute latency by
12770 instructing cooperating clients to be more or less patient when a store
12773 @item --cache-bypass-threshold=@var{size}
12774 When used in conjunction with @option{--cache}, store items smaller than
12775 @var{size} are immediately available, even when they are not yet in
12776 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12777 for megabytes and so on. The default is @code{10M}.
12779 ``Cache bypass'' allows you to reduce the publication delay for clients
12780 at the expense of possibly additional I/O and CPU use on the server
12781 side: depending on the client access patterns, those store items can end
12782 up being baked several times until a copy is available in cache.
12784 Increasing the threshold may be useful for sites that have few users, or
12785 to guarantee that users get substitutes even for store items that are
12788 @item --nar-path=@var{path}
12789 Use @var{path} as the prefix for the URLs of ``nar'' files
12790 (@pxref{Invoking guix archive, normalized archives}).
12792 By default, nars are served at a URL such as
12793 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12794 change the @code{/nar} part to @var{path}.
12796 @item --public-key=@var{file}
12797 @itemx --private-key=@var{file}
12798 Use the specific @var{file}s as the public/private key pair used to sign
12799 the store items being published.
12801 The files must correspond to the same key pair (the private key is used
12802 for signing and the public key is merely advertised in the signature
12803 metadata). They must contain keys in the canonical s-expression format
12804 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12805 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12806 @file{/etc/guix/signing-key.sec} are used.
12808 @item --repl[=@var{port}]
12809 @itemx -r [@var{port}]
12810 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12811 Reference Manual}) on @var{port} (37146 by default). This is used
12812 primarily for debugging a running @command{guix publish} server.
12815 Enabling @command{guix publish} on Guix System is a one-liner: just
12816 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12817 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12818 @code{guix-publish-service-type}}).
12820 If you are instead running Guix on a ``foreign distro'', follow these
12825 If your host distro uses the systemd init system:
12828 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12829 /etc/systemd/system/
12830 # systemctl start guix-publish && systemctl enable guix-publish
12834 If your host distro uses the Upstart init system:
12837 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12838 # start guix-publish
12842 Otherwise, proceed similarly with your distro's init system.
12845 @node Invoking guix challenge
12846 @section Invoking @command{guix challenge}
12848 @cindex reproducible builds
12849 @cindex verifiable builds
12850 @cindex @command{guix challenge}
12852 Do the binaries provided by this server really correspond to the source
12853 code it claims to build? Is a package build process deterministic?
12854 These are the questions the @command{guix challenge} command attempts to
12857 The former is obviously an important question: Before using a substitute
12858 server (@pxref{Substitutes}), one had better @emph{verify} that it
12859 provides the right binaries, and thus @emph{challenge} it. The latter
12860 is what enables the former: If package builds are deterministic, then
12861 independent builds of the package should yield the exact same result,
12862 bit for bit; if a server provides a binary different from the one
12863 obtained locally, it may be either corrupt or malicious.
12865 We know that the hash that shows up in @file{/gnu/store} file names is
12866 the hash of all the inputs of the process that built the file or
12867 directory---compilers, libraries, build scripts,
12868 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12869 one store file name should map to exactly one build output.
12870 @command{guix challenge} checks whether there is, indeed, a single
12871 mapping by comparing the build outputs of several independent builds of
12872 any given store item.
12874 The command output looks like this:
12877 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER-1} https://guix.example.org"
12878 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER-1}'... 100.0%
12879 updating list of substitutes from 'https://guix.example.org'... 100.0%
12880 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12881 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12882 https://@value{SUBSTITUTE-SERVER-1}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12883 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12885 /lib/libcrypto.so.1.1
12888 /gnu/store/@dots{}-git-2.5.0 contents differ:
12889 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12890 https://@value{SUBSTITUTE-SERVER-1}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12891 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12893 /libexec/git-core/git-fsck
12895 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12896 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12897 https://@value{SUBSTITUTE-SERVER-1}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12898 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12900 /share/man/man1/pius.1.gz
12904 6,406 store items were analyzed:
12905 - 4,749 (74.1%) were identical
12906 - 525 (8.2%) differed
12907 - 1,132 (17.7%) were inconclusive
12911 In this example, @command{guix challenge} first scans the store to
12912 determine the set of locally-built derivations---as opposed to store
12913 items that were downloaded from a substitute server---and then queries
12914 all the substitute servers. It then reports those store items for which
12915 the servers obtained a result different from the local build.
12917 @cindex non-determinism, in package builds
12918 As an example, @code{guix.example.org} always gets a different answer.
12919 Conversely, @code{@value{SUBSTITUTE-SERVER-1}} agrees with local builds, except in the
12920 case of Git. This might indicate that the build process of Git is
12921 non-deterministic, meaning that its output varies as a function of
12922 various things that Guix does not fully control, in spite of building
12923 packages in isolated environments (@pxref{Features}). Most common
12924 sources of non-determinism include the addition of timestamps in build
12925 results, the inclusion of random numbers, and directory listings sorted
12926 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12929 To find out what is wrong with this Git binary, the easiest approach is
12933 guix challenge git \
12934 --diff=diffoscope \
12935 --substitute-urls="https://@value{SUBSTITUTE-SERVER-1} https://guix.example.org"
12938 This automatically invokes @command{diffoscope}, which displays detailed
12939 information about files that differ.
12941 Alternatively, we can do something along these lines (@pxref{Invoking guix
12945 $ wget -q -O - https://@value{SUBSTITUTE-SERVER-1}/nar/lzip/@dots{}-git-2.5.0 \
12946 | lzip -d | guix archive -x /tmp/git
12947 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12950 This command shows the difference between the files resulting from the
12951 local build, and the files resulting from the build on
12952 @code{@value{SUBSTITUTE-SERVER-1}} (@pxref{Overview, Comparing and Merging Files,,
12953 diffutils, Comparing and Merging Files}). The @command{diff} command
12954 works great for text files. When binary files differ, a better option
12955 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12956 visualize differences for all kinds of files.
12958 Once you have done that work, you can tell whether the differences are due
12959 to a non-deterministic build process or to a malicious server. We try
12960 hard to remove sources of non-determinism in packages to make it easier
12961 to verify substitutes, but of course, this is a process that
12962 involves not just Guix, but a large part of the free software community.
12963 In the meantime, @command{guix challenge} is one tool to help address
12966 If you are writing packages for Guix, you are encouraged to check
12967 whether @code{@value{SUBSTITUTE-SERVER-1}} and other substitute servers obtain the
12968 same build result as you did with:
12971 $ guix challenge @var{package}
12975 where @var{package} is a package specification such as
12976 @code{guile@@2.0} or @code{glibc:debug}.
12978 The general syntax is:
12981 guix challenge @var{options} [@var{packages}@dots{}]
12984 When a difference is found between the hash of a locally-built item and
12985 that of a server-provided substitute, or among substitutes provided by
12986 different servers, the command displays it as in the example above and
12987 its exit code is 2 (other non-zero exit codes denote other kinds of
12990 The one option that matters is:
12994 @item --substitute-urls=@var{urls}
12995 Consider @var{urls} the whitespace-separated list of substitute source
12996 URLs to compare to.
12998 @item --diff=@var{mode}
12999 Upon mismatches, show differences according to @var{mode}, one of:
13002 @item @code{simple} (the default)
13003 Show the list of files that differ.
13005 @item @code{diffoscope}
13006 @itemx @var{command}
13007 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
13008 two directories whose contents do not match.
13010 When @var{command} is an absolute file name, run @var{command} instead
13014 Do not show further details about the differences.
13017 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
13018 downloads the store items from the given substitute servers so that it
13023 Show details about matches (identical contents) in addition to
13024 information about mismatches.
13028 @node Invoking guix copy
13029 @section Invoking @command{guix copy}
13031 @cindex copy, of store items, over SSH
13032 @cindex SSH, copy of store items
13033 @cindex sharing store items across machines
13034 @cindex transferring store items across machines
13035 The @command{guix copy} command copies items from the store of one
13036 machine to that of another machine over a secure shell (SSH)
13037 connection@footnote{This command is available only when Guile-SSH was
13038 found. @xref{Requirements}, for details.}. For example, the following
13039 command copies the @code{coreutils} package, the user's profile, and all
13040 their dependencies over to @var{host}, logged in as @var{user}:
13043 guix copy --to=@var{user}@@@var{host} \
13044 coreutils $(readlink -f ~/.guix-profile)
13047 If some of the items to be copied are already present on @var{host},
13048 they are not actually sent.
13050 The command below retrieves @code{libreoffice} and @code{gimp} from
13051 @var{host}, assuming they are available there:
13054 guix copy --from=@var{host} libreoffice gimp
13057 The SSH connection is established using the Guile-SSH client, which is
13058 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
13059 @file{~/.ssh/config}, and uses the SSH agent for authentication.
13061 The key used to sign items that are sent must be accepted by the remote
13062 machine. Likewise, the key used by the remote machine to sign items you
13063 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
13064 own daemon. @xref{Invoking guix archive}, for more information about
13065 store item authentication.
13067 The general syntax is:
13070 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
13073 You must always specify one of the following options:
13076 @item --to=@var{spec}
13077 @itemx --from=@var{spec}
13078 Specify the host to send to or receive from. @var{spec} must be an SSH
13079 spec such as @code{example.org}, @code{charlie@@example.org}, or
13080 @code{charlie@@example.org:2222}.
13083 The @var{items} can be either package names, such as @code{gimp}, or
13084 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
13086 When specifying the name of a package to send, it is first built if
13087 needed, unless @option{--dry-run} was specified. Common build options
13088 are supported (@pxref{Common Build Options}).
13091 @node Invoking guix container
13092 @section Invoking @command{guix container}
13094 @cindex @command{guix container}
13096 As of version @value{VERSION}, this tool is experimental. The interface
13097 is subject to radical change in the future.
13100 The purpose of @command{guix container} is to manipulate processes
13101 running within an isolated environment, commonly known as a
13102 ``container'', typically created by the @command{guix environment}
13103 (@pxref{Invoking guix environment}) and @command{guix system container}
13104 (@pxref{Invoking guix system}) commands.
13106 The general syntax is:
13109 guix container @var{action} @var{options}@dots{}
13112 @var{action} specifies the operation to perform with a container, and
13113 @var{options} specifies the context-specific arguments for the action.
13115 The following actions are available:
13119 Execute a command within the context of a running container.
13124 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
13127 @var{pid} specifies the process ID of the running container.
13128 @var{program} specifies an executable file name within the root file
13129 system of the container. @var{arguments} are the additional options that
13130 will be passed to @var{program}.
13132 The following command launches an interactive login shell inside a
13133 Guix system container, started by @command{guix system container}, and whose
13134 process ID is 9001:
13137 guix container exec 9001 /run/current-system/profile/bin/bash --login
13140 Note that the @var{pid} cannot be the parent process of a container. It
13141 must be PID 1 of the container or one of its child processes.
13145 @node Invoking guix weather
13146 @section Invoking @command{guix weather}
13148 Occasionally you're grumpy because substitutes are lacking and you end
13149 up building packages by yourself (@pxref{Substitutes}). The
13150 @command{guix weather} command reports on substitute availability on the
13151 specified servers so you can have an idea of whether you'll be grumpy
13152 today. It can sometimes be useful info as a user, but it is primarily
13153 useful to people running @command{guix publish} (@pxref{Invoking guix
13156 @cindex statistics, for substitutes
13157 @cindex availability of substitutes
13158 @cindex substitute availability
13159 @cindex weather, substitute availability
13160 Here's a sample run:
13163 $ guix weather --substitute-urls=https://guix.example.org
13164 computing 5,872 package derivations for x86_64-linux...
13165 looking for 6,128 store items on https://guix.example.org..
13166 updating list of substitutes from 'https://guix.example.org'... 100.0%
13167 https://guix.example.org
13168 43.4% substitutes available (2,658 out of 6,128)
13169 7,032.5 MiB of nars (compressed)
13170 19,824.2 MiB on disk (uncompressed)
13171 0.030 seconds per request (182.9 seconds in total)
13172 33.5 requests per second
13174 9.8% (342 out of 3,470) of the missing items are queued
13176 x86_64-linux: 518 (59.7%)
13177 i686-linux: 221 (25.5%)
13178 aarch64-linux: 128 (14.8%)
13179 build rate: 23.41 builds per hour
13180 x86_64-linux: 11.16 builds per hour
13181 i686-linux: 6.03 builds per hour
13182 aarch64-linux: 6.41 builds per hour
13185 @cindex continuous integration, statistics
13186 As you can see, it reports the fraction of all the packages for which
13187 substitutes are available on the server---regardless of whether
13188 substitutes are enabled, and regardless of whether this server's signing
13189 key is authorized. It also reports the size of the compressed archives
13190 (``nars'') provided by the server, the size the corresponding store
13191 items occupy in the store (assuming deduplication is turned off), and
13192 the server's throughput. The second part gives continuous integration
13193 (CI) statistics, if the server supports it. In addition, using the
13194 @option{--coverage} option, @command{guix weather} can list ``important''
13195 package substitutes missing on the server (see below).
13197 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
13198 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
13199 challenge}, it ignores signatures on those substitutes, which is
13200 innocuous since the command only gathers statistics and cannot install
13203 The general syntax is:
13206 guix weather @var{options}@dots{} [@var{packages}@dots{}]
13209 When @var{packages} is omitted, @command{guix weather} checks the availability
13210 of substitutes for @emph{all} the packages, or for those specified with
13211 @option{--manifest}; otherwise it only considers the specified packages. It
13212 is also possible to query specific system types with @option{--system}.
13213 @command{guix weather} exits with a non-zero code when the fraction of
13214 available substitutes is below 100%.
13216 The available options are listed below.
13219 @item --substitute-urls=@var{urls}
13220 @var{urls} is the space-separated list of substitute server URLs to
13221 query. When this option is omitted, the default set of substitute
13222 servers is queried.
13224 @item --system=@var{system}
13225 @itemx -s @var{system}
13226 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
13227 option can be repeated, in which case @command{guix weather} will query
13228 substitutes for several system types.
13230 @item --manifest=@var{file}
13231 Instead of querying substitutes for all the packages, only ask for those
13232 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
13233 with the @code{-m} option of @command{guix package} (@pxref{Invoking
13236 This option can be repeated several times, in which case the manifests
13239 @item --coverage[=@var{count}]
13240 @itemx -c [@var{count}]
13241 Report on substitute coverage for packages: list packages with at least
13242 @var{count} dependents (zero by default) for which substitutes are
13243 unavailable. Dependent packages themselves are not listed: if @var{b} depends
13244 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
13245 @var{b} usually lacks substitutes as well. The result looks like this:
13248 $ guix weather --substitute-urls=@value{SUBSTITUTE-URLS} -c 10
13249 computing 8,983 package derivations for x86_64-linux...
13250 looking for 9,343 store items on @value{SUBSTITUTE-URLS}...
13251 updating substitutes from '@value{SUBSTITUTE-URLS}'... 100.0%
13252 @value{SUBSTITUTE-URLS}
13253 64.7% substitutes available (6,047 out of 9,343)
13255 2502 packages are missing from '@value{SUBSTITUTE-URLS}' for 'x86_64-linux', among which:
13256 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
13257 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
13258 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
13262 What this example shows is that @code{kcoreaddons} and presumably the 58
13263 packages that depend on it have no substitutes at
13264 @code{@value{SUBSTITUTE-SERVER-1}}; likewise for @code{qgpgme} and the 46
13265 packages that depend on it.
13267 If you are a Guix developer, or if you are taking care of this build farm,
13268 you'll probably want to have a closer look at these packages: they may simply
13271 @item --display-missing
13272 Display the list of store items for which substitutes are missing.
13275 @node Invoking guix processes
13276 @section Invoking @command{guix processes}
13278 The @command{guix processes} command can be useful to developers and system
13279 administrators, especially on multi-user machines and on build farms: it lists
13280 the current sessions (connections to the daemon), as well as information about
13281 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
13282 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
13283 listed.}. Here's an example of the information it returns:
13286 $ sudo guix processes
13289 ClientCommand: guix environment --ad-hoc python
13293 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
13297 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13298 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
13299 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
13300 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
13302 ChildCommand: guix offload x86_64-linux 7200 1 28800
13304 ChildCommand: guix offload x86_64-linux 7200 1 28800
13306 ChildCommand: guix offload x86_64-linux 7200 1 28800
13309 In this example we see that @command{guix-daemon} has three clients:
13310 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
13311 integration tool; their process identifier (PID) is given by the
13312 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
13313 @command{guix-daemon} sub-process of this particular session.
13315 The @code{LockHeld} fields show which store items are currently locked
13316 by this session, which corresponds to store items being built or
13317 substituted (the @code{LockHeld} field is not displayed when
13318 @command{guix processes} is not running as root). Last, by looking at
13319 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
13320 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
13322 The output is in Recutils format so we can use the handy @command{recsel}
13323 command to select sessions of interest (@pxref{Selection Expressions,,,
13324 recutils, GNU recutils manual}). As an example, the command shows the command
13325 line and PID of the client that triggered the build of a Perl package:
13328 $ sudo guix processes | \
13329 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
13331 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13334 Additional options are listed below.
13337 @item --format=@var{format}
13338 @itemx -f @var{format}
13339 Produce output in the specified @var{format}, one of:
13343 The default option. It outputs a set of Session recutils records
13344 that include each @code{ChildProcess} as a field.
13347 Normalize the output records into record sets (@pxref{Record Sets,,,
13348 recutils, GNU recutils manual}). Normalizing into record sets allows
13349 joins across record types. The example below lists the PID of each
13350 @code{ChildProcess} and the associated PID for @code{Session} that
13351 spawned the @code{ChildProcess} where the @code{Session} was started
13352 using @command{guix build}.
13355 $ guix processes --format=normalized | \
13359 -p Session.PID,PID \
13360 -e 'Session.ClientCommand ~ "guix build"'
13373 @node System Configuration
13374 @chapter System Configuration
13376 @cindex system configuration
13377 Guix System supports a consistent whole-system configuration
13378 mechanism. By that we mean that all aspects of the global system
13379 configuration---such as the available system services, timezone and
13380 locale settings, user accounts---are declared in a single place. Such
13381 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13383 One of the advantages of putting all the system configuration under the
13384 control of Guix is that it supports transactional system upgrades, and
13385 makes it possible to roll back to a previous system instantiation,
13386 should something go wrong with the new one (@pxref{Features}). Another
13387 advantage is that it makes it easy to replicate the exact same configuration
13388 across different machines, or at different points in time, without
13389 having to resort to additional administration tools layered on top of
13390 the own tools of the system.
13391 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13393 This section describes this mechanism. First we focus on the system
13394 administrator's viewpoint---explaining how the system is configured and
13395 instantiated. Then we show how this mechanism can be extended, for
13396 instance to support new system services.
13399 * Using the Configuration System:: Customizing your GNU system.
13400 * operating-system Reference:: Detail of operating-system declarations.
13401 * File Systems:: Configuring file system mounts.
13402 * Mapped Devices:: Block device extra processing.
13403 * User Accounts:: Specifying user accounts.
13404 * Keyboard Layout:: How the system interprets key strokes.
13405 * Locales:: Language and cultural convention settings.
13406 * Services:: Specifying system services.
13407 * Setuid Programs:: Programs running with root privileges.
13408 * X.509 Certificates:: Authenticating HTTPS servers.
13409 * Name Service Switch:: Configuring libc's name service switch.
13410 * Initial RAM Disk:: Linux-Libre bootstrapping.
13411 * Bootloader Configuration:: Configuring the boot loader.
13412 * Invoking guix system:: Instantiating a system configuration.
13413 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13414 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13415 * Defining Services:: Adding new service definitions.
13418 @node Using the Configuration System
13419 @section Using the Configuration System
13421 The operating system is configured by providing an
13422 @code{operating-system} declaration in a file that can then be passed to
13423 the @command{guix system} command (@pxref{Invoking guix system}). A
13424 simple setup, with the default system services, the default Linux-Libre
13425 kernel, initial RAM disk, and boot loader looks like this:
13427 @findex operating-system
13429 @include os-config-bare-bones.texi
13432 This example should be self-describing. Some of the fields defined
13433 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13434 Others, such as @code{packages} and @code{services}, can be omitted, in
13435 which case they get a default value.
13437 Below we discuss the effect of some of the most important fields
13438 (@pxref{operating-system Reference}, for details about all the available
13439 fields), and how to @dfn{instantiate} the operating system using
13440 @command{guix system}.
13442 @unnumberedsubsec Bootloader
13444 @cindex legacy boot, on Intel machines
13445 @cindex BIOS boot, on Intel machines
13448 The @code{bootloader} field describes the method that will be used to boot
13449 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13450 mode, as in the example above. However, more recent machines rely instead on
13451 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13452 the @code{bootloader} field should contain something along these lines:
13455 (bootloader-configuration
13456 (bootloader grub-efi-bootloader)
13457 (target "/boot/efi"))
13460 @xref{Bootloader Configuration}, for more information on the available
13461 configuration options.
13463 @unnumberedsubsec Globally-Visible Packages
13465 @vindex %base-packages
13466 The @code{packages} field lists packages that will be globally visible
13467 on the system, for all user accounts---i.e., in every user's @env{PATH}
13468 environment variable---in addition to the per-user profiles
13469 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13470 provides all the tools one would expect for basic user and administrator
13471 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13472 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13473 etc. The example above adds GNU@tie{}Screen to those,
13474 taken from the @code{(gnu packages screen)}
13475 module (@pxref{Package Modules}). The
13476 @code{(list package output)} syntax can be used to add a specific output
13480 (use-modules (gnu packages))
13481 (use-modules (gnu packages dns))
13485 (packages (cons (list isc-bind "utils")
13489 @findex specification->package
13490 Referring to packages by variable name, like @code{isc-bind} above, has
13491 the advantage of being unambiguous; it also allows typos and such to be
13492 diagnosed right away as ``unbound variables''. The downside is that one
13493 needs to know which module defines which package, and to augment the
13494 @code{use-package-modules} line accordingly. To avoid that, one can use
13495 the @code{specification->package} procedure of the @code{(gnu packages)}
13496 module, which returns the best package for a given name or name and
13500 (use-modules (gnu packages))
13504 (packages (append (map specification->package
13505 '("tcpdump" "htop" "gnupg@@2.0"))
13509 @unnumberedsubsec System Services
13512 @vindex %base-services
13513 The @code{services} field lists @dfn{system services} to be made
13514 available when the system starts (@pxref{Services}).
13515 The @code{operating-system} declaration above specifies that, in
13516 addition to the basic services, we want the OpenSSH secure shell
13517 daemon listening on port 2222 (@pxref{Networking Services,
13518 @code{openssh-service-type}}). Under the hood,
13519 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13520 right command-line options, possibly with supporting configuration files
13521 generated as needed (@pxref{Defining Services}).
13523 @cindex customization, of services
13524 @findex modify-services
13525 Occasionally, instead of using the base services as is, you will want to
13526 customize them. To do this, use @code{modify-services} (@pxref{Service
13527 Reference, @code{modify-services}}) to modify the list.
13529 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13530 (the console log-in) in the @code{%base-services} list (@pxref{Base
13531 Services, @code{%base-services}}). To do that, you can write the
13532 following in your operating system declaration:
13535 (define %my-services
13536 ;; My very own list of services.
13537 (modify-services %base-services
13538 (guix-service-type config =>
13539 (guix-configuration
13541 ;; Fetch substitutes from example.org.
13543 (list "https://example.org/guix"
13544 "https://ci.guix.gnu.org"))))
13545 (mingetty-service-type config =>
13546 (mingetty-configuration
13548 ;; Automatially log in as "guest".
13549 (auto-login "guest")))))
13553 (services %my-services))
13556 This changes the configuration---i.e., the service parameters---of the
13557 @code{guix-service-type} instance, and that of all the
13558 @code{mingetty-service-type} instances in the @code{%base-services} list.
13559 Observe how this is accomplished: first, we arrange for the original
13560 configuration to be bound to the identifier @code{config} in the
13561 @var{body}, and then we write the @var{body} so that it evaluates to the
13562 desired configuration. In particular, notice how we use @code{inherit}
13563 to create a new configuration which has the same values as the old
13564 configuration, but with a few modifications.
13566 @cindex encrypted disk
13567 The configuration for a typical ``desktop'' usage, with an encrypted
13568 root partition, the X11 display
13569 server, GNOME and Xfce (users can choose which of these desktop
13570 environments to use at the log-in screen by pressing @kbd{F1}), network
13571 management, power management, and more, would look like this:
13574 @include os-config-desktop.texi
13577 A graphical system with a choice of lightweight window managers
13578 instead of full-blown desktop environments would look like this:
13581 @include os-config-lightweight-desktop.texi
13584 This example refers to the @file{/boot/efi} file system by its UUID,
13585 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13586 as returned by the @command{blkid} command.
13588 @xref{Desktop Services}, for the exact list of services provided by
13589 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13590 information about the @code{nss-certs} package that is used here.
13592 Again, @code{%desktop-services} is just a list of service objects. If
13593 you want to remove services from there, you can do so using the
13594 procedures for list filtering (@pxref{SRFI-1 Filtering and
13595 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13596 following expression returns a list that contains all the services in
13597 @code{%desktop-services} minus the Avahi service:
13600 (remove (lambda (service)
13601 (eq? (service-kind service) avahi-service-type))
13605 Alternatively, the @code{modify-services} macro can be used:
13608 (modify-services %desktop-services
13609 (delete avahi-service-type))
13613 @unnumberedsubsec Instantiating the System
13615 Assuming the @code{operating-system} declaration
13616 is stored in the @file{my-system-config.scm}
13617 file, the @command{guix system reconfigure my-system-config.scm} command
13618 instantiates that configuration, and makes it the default GRUB boot
13619 entry (@pxref{Invoking guix system}).
13621 The normal way to change the system configuration is by updating this
13622 file and re-running @command{guix system reconfigure}. One should never
13623 have to touch files in @file{/etc} or to run commands that modify the
13624 system state such as @command{useradd} or @command{grub-install}. In
13625 fact, you must avoid that since that would not only void your warranty
13626 but also prevent you from rolling back to previous versions of your
13627 system, should you ever need to.
13629 @cindex roll-back, of the operating system
13630 Speaking of roll-back, each time you run @command{guix system
13631 reconfigure}, a new @dfn{generation} of the system is created---without
13632 modifying or deleting previous generations. Old system generations get
13633 an entry in the bootloader boot menu, allowing you to boot them in case
13634 something went wrong with the latest generation. Reassuring, no? The
13635 @command{guix system list-generations} command lists the system
13636 generations available on disk. It is also possible to roll back the
13637 system via the commands @command{guix system roll-back} and
13638 @command{guix system switch-generation}.
13640 Although the @command{guix system reconfigure} command will not modify
13641 previous generations, you must take care when the current generation is not
13642 the latest (e.g., after invoking @command{guix system roll-back}), since
13643 the operation might overwrite a later generation (@pxref{Invoking guix
13646 @unnumberedsubsec The Programming Interface
13648 At the Scheme level, the bulk of an @code{operating-system} declaration
13649 is instantiated with the following monadic procedure (@pxref{The Store
13652 @deffn {Monadic Procedure} operating-system-derivation os
13653 Return a derivation that builds @var{os}, an @code{operating-system}
13654 object (@pxref{Derivations}).
13656 The output of the derivation is a single directory that refers to all
13657 the packages, configuration files, and other supporting files needed to
13658 instantiate @var{os}.
13661 This procedure is provided by the @code{(gnu system)} module. Along
13662 with @code{(gnu services)} (@pxref{Services}), this module contains the
13663 guts of Guix System. Make sure to visit it!
13666 @node operating-system Reference
13667 @section @code{operating-system} Reference
13669 This section summarizes all the options available in
13670 @code{operating-system} declarations (@pxref{Using the Configuration
13673 @deftp {Data Type} operating-system
13674 This is the data type representing an operating system configuration.
13675 By that, we mean all the global system configuration, not per-user
13676 configuration (@pxref{Using the Configuration System}).
13679 @item @code{kernel} (default: @code{linux-libre})
13680 The package object of the operating system kernel to
13681 use@footnote{Currently only the Linux-libre kernel is fully supported.
13682 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13683 available when building a virtual machine disk image.}.
13686 @item @code{hurd} (default: @code{#f})
13687 The package object of the Hurd to be started by the kernel. When this
13688 field is set, produce a GNU/Hurd operating system. In that case,
13689 @code{kernel} must also be set to the @code{gnumach} package---the
13690 microkernel the Hurd runs on.
13693 This feature is experimental and only supported for disk images.
13696 @item @code{kernel-loadable-modules} (default: '())
13697 A list of objects (usually packages) to collect loadable kernel modules
13698 from--e.g. @code{(list ddcci-driver-linux)}.
13700 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13701 List of strings or gexps representing additional arguments to pass on
13702 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13704 @item @code{bootloader}
13705 The system bootloader configuration object. @xref{Bootloader Configuration}.
13708 This is the label (a string) as it appears in the bootloader's menu entry.
13709 The default label includes the kernel name and version.
13711 @item @code{keyboard-layout} (default: @code{#f})
13712 This field specifies the keyboard layout to use in the console. It can be
13713 either @code{#f}, in which case the default keyboard layout is used (usually
13714 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
13715 for more information.
13717 This keyboard layout is in effect as soon as the kernel has booted. For
13718 instance, it is the keyboard layout in effect when you type a passphrase if
13719 your root file system is on a @code{luks-device-mapping} mapped device
13720 (@pxref{Mapped Devices}).
13723 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13724 that used by the graphical display server. @xref{Bootloader Configuration},
13725 for information on how to specify the bootloader's keyboard layout. @xref{X
13726 Window}, for information on how to specify the keyboard layout used by the X
13730 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13732 @cindex initial RAM disk
13733 The list of Linux kernel modules that need to be available in the
13734 initial RAM disk. @xref{Initial RAM Disk}.
13736 @item @code{initrd} (default: @code{base-initrd})
13737 A procedure that returns an initial RAM disk for the Linux
13738 kernel. This field is provided to support low-level customization and
13739 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13741 @item @code{firmware} (default: @code{%base-firmware})
13743 List of firmware packages loadable by the operating system kernel.
13745 The default includes firmware needed for Atheros- and Broadcom-based
13746 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13747 respectively). @xref{Hardware Considerations}, for more info on
13748 supported hardware.
13750 @item @code{host-name}
13753 @item @code{hosts-file}
13755 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13756 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13757 Reference Manual}). The default is a file with entries for
13758 @code{localhost} and @var{host-name}.
13760 @item @code{mapped-devices} (default: @code{'()})
13761 A list of mapped devices. @xref{Mapped Devices}.
13763 @item @code{file-systems}
13764 A list of file systems. @xref{File Systems}.
13766 @cindex swap devices
13768 @item @code{swap-devices} (default: @code{'()})
13769 A list of UUIDs, file system labels, or strings identifying devices or
13770 files to be used for ``swap
13771 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13772 Manual}). Here are some examples:
13775 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13776 Use the swap partition with the given UUID@. You can learn the UUID of a
13777 Linux swap partition by running @command{swaplabel @var{device}}, where
13778 @var{device} is the @file{/dev} file name of that partition.
13780 @item (list (file-system-label "swap"))
13781 Use the partition with label @code{swap}. Again, the
13782 @command{swaplabel} command allows you to view and change the label of a
13783 Linux swap partition.
13785 @item (list "/swapfile")
13786 Use the file @file{/swapfile} as swap space.
13788 @item (list "/dev/sda3" "/dev/sdb2")
13789 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13790 We recommend referring to swap devices by UUIDs or labels as shown above
13794 It is possible to specify a swap file in a file system on a mapped
13795 device (under @file{/dev/mapper}), provided that the necessary device
13796 mapping and file system are also specified. @xref{Mapped Devices} and
13797 @ref{File Systems}.
13799 @item @code{users} (default: @code{%base-user-accounts})
13800 @itemx @code{groups} (default: @code{%base-groups})
13801 List of user accounts and groups. @xref{User Accounts}.
13803 If the @code{users} list lacks a user account with UID@tie{}0, a
13804 ``root'' account with UID@tie{}0 is automatically added.
13806 @item @code{skeletons} (default: @code{(default-skeletons)})
13807 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13808 file-like objects}). These are the skeleton files that will be added to
13809 the home directory of newly-created user accounts.
13811 For instance, a valid value may look like this:
13814 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13815 (".guile" ,(plain-file "guile"
13816 "(use-modules (ice-9 readline))
13817 (activate-readline)")))
13820 @item @code{issue} (default: @code{%default-issue})
13821 A string denoting the contents of the @file{/etc/issue} file, which is
13822 displayed when users log in on a text console.
13824 @item @code{packages} (default: @code{%base-packages})
13825 A list of packages to be installed in the global profile, which is accessible
13826 at @file{/run/current-system/profile}. Each element is either a package
13827 variable or a package/output tuple. Here's a simple example of both:
13830 (cons* git ; the default "out" output
13831 (list git "send-email") ; another output of git
13832 %base-packages) ; the default set
13835 The default set includes core utilities and it is good practice to
13836 install non-core utilities in user profiles (@pxref{Invoking guix
13839 @item @code{timezone}
13840 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13842 You can run the @command{tzselect} command to find out which timezone
13843 string corresponds to your region. Choosing an invalid timezone name
13844 causes @command{guix system} to fail.
13846 @item @code{locale} (default: @code{"en_US.utf8"})
13847 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13848 Library Reference Manual}). @xref{Locales}, for more information.
13850 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13851 The list of locale definitions to be compiled and that may be used at
13852 run time. @xref{Locales}.
13854 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13855 The list of GNU@tie{}libc packages whose locale data and tools are used
13856 to build the locale definitions. @xref{Locales}, for compatibility
13857 considerations that justify this option.
13859 @item @code{name-service-switch} (default: @code{%default-nss})
13860 Configuration of the libc name service switch (NSS)---a
13861 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13864 @item @code{services} (default: @code{%base-services})
13865 A list of service objects denoting system services. @xref{Services}.
13867 @cindex essential services
13868 @item @code{essential-services} (default: ...)
13869 The list of ``essential services''---i.e., things like instances of
13870 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13871 Reference}), which are derived from the operating system definition itself.
13872 As a user you should @emph{never} need to touch this field.
13874 @item @code{pam-services} (default: @code{(base-pam-services)})
13876 @cindex pluggable authentication modules
13877 Linux @dfn{pluggable authentication module} (PAM) services.
13878 @c FIXME: Add xref to PAM services section.
13880 @item @code{setuid-programs} (default: @code{%setuid-programs})
13881 List of string-valued G-expressions denoting setuid programs.
13882 @xref{Setuid Programs}.
13884 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13885 @cindex sudoers file
13886 The contents of the @file{/etc/sudoers} file as a file-like object
13887 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13889 This file specifies which users can use the @command{sudo} command, what
13890 they are allowed to do, and what privileges they may gain. The default
13891 is that only @code{root} and members of the @code{wheel} group may use
13896 @deffn {Scheme Syntax} this-operating-system
13897 When used in the @emph{lexical scope} of an operating system field definition,
13898 this identifier resolves to the operating system being defined.
13900 The example below shows how to refer to the operating system being defined in
13901 the definition of the @code{label} field:
13904 (use-modules (gnu) (guix))
13908 (label (package-full-name
13909 (operating-system-kernel this-operating-system))))
13912 It is an error to refer to @code{this-operating-system} outside an operating
13919 @section File Systems
13921 The list of file systems to be mounted is specified in the
13922 @code{file-systems} field of the operating system declaration
13923 (@pxref{Using the Configuration System}). Each file system is declared
13924 using the @code{file-system} form, like this:
13928 (mount-point "/home")
13929 (device "/dev/sda3")
13933 As usual, some of the fields are mandatory---those shown in the example
13934 above---while others can be omitted. These are described below.
13936 @deftp {Data Type} file-system
13937 Objects of this type represent file systems to be mounted. They
13938 contain the following members:
13942 This is a string specifying the type of the file system---e.g.,
13945 @item @code{mount-point}
13946 This designates the place where the file system is to be mounted.
13948 @item @code{device}
13949 This names the ``source'' of the file system. It can be one of three
13950 things: a file system label, a file system UUID, or the name of a
13951 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13952 systems without having to hard-code their actual device
13953 name@footnote{Note that, while it is tempting to use
13954 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13955 result, this is not recommended: These special device nodes are created
13956 by the udev daemon and may be unavailable at the time the device is
13959 @findex file-system-label
13960 File system labels are created using the @code{file-system-label}
13961 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13962 plain strings. Here's an example of a file system referred to by its
13963 label, as shown by the @command{e2label} command:
13967 (mount-point "/home")
13969 (device (file-system-label "my-home")))
13973 UUIDs are converted from their string representation (as shown by the
13974 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13975 @code{uuid} form expects 16-byte UUIDs as defined in
13976 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13977 form of UUID used by the ext2 family of file systems and others, but it
13978 is different from ``UUIDs'' found in FAT file systems, for instance.},
13983 (mount-point "/home")
13985 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13988 When the source of a file system is a mapped device (@pxref{Mapped
13989 Devices}), its @code{device} field @emph{must} refer to the mapped
13990 device name---e.g., @file{"/dev/mapper/root-partition"}.
13991 This is required so that
13992 the system knows that mounting the file system depends on having the
13993 corresponding device mapping established.
13995 @item @code{flags} (default: @code{'()})
13996 This is a list of symbols denoting mount flags. Recognized flags
13997 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13998 access to special files), @code{no-suid} (ignore setuid and setgid
13999 bits), @code{no-atime} (do not update file access times),
14000 @code{strict-atime} (update file access time), @code{lazy-time} (only
14001 update time on the in-memory version of the file inode), and
14002 @code{no-exec} (disallow program execution).
14003 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
14004 Manual}, for more information on these flags.
14006 @item @code{options} (default: @code{#f})
14007 This is either @code{#f}, or a string denoting mount options passed to
14008 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
14009 Library Reference Manual}, for details and run @command{man 8 mount} for
14010 options for various file systems. Note that the
14011 @code{file-system-options->alist} and @code{alist->file-system-options}
14012 procedures from @code{(gnu system file-systems)} can be used to convert
14013 file system options given as an association list to the string
14014 representation, and vice-versa.
14016 @item @code{mount?} (default: @code{#t})
14017 This value indicates whether to automatically mount the file system when
14018 the system is brought up. When set to @code{#f}, the file system gets
14019 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
14020 is not automatically mounted.
14022 @item @code{needed-for-boot?} (default: @code{#f})
14023 This Boolean value indicates whether the file system is needed when
14024 booting. If that is true, then the file system is mounted when the
14025 initial RAM disk (initrd) is loaded. This is always the case, for
14026 instance, for the root file system.
14028 @item @code{check?} (default: @code{#t})
14029 This Boolean indicates whether the file system needs to be checked for
14030 errors before being mounted.
14032 @item @code{create-mount-point?} (default: @code{#f})
14033 When true, the mount point is created if it does not exist yet.
14035 @item @code{mount-may-fail?} (default: @code{#f})
14036 When true, this indicates that mounting this file system can fail but
14037 that should not be considered an error. This is useful in unusual
14038 cases; an example of this is @code{efivarfs}, a file system that can
14039 only be mounted on EFI/UEFI systems.
14041 @item @code{dependencies} (default: @code{'()})
14042 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
14043 representing file systems that must be mounted or mapped devices that
14044 must be opened before (and unmounted or closed after) this one.
14046 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
14047 a dependency of @file{/sys/fs/cgroup/cpu} and
14048 @file{/sys/fs/cgroup/memory}.
14050 Another example is a file system that depends on a mapped device, for
14051 example for an encrypted partition (@pxref{Mapped Devices}).
14055 @deffn {Scheme Procedure} file-system-label @var{str}
14056 This procedure returns an opaque file system label from @var{str}, a
14060 (file-system-label "home")
14061 @result{} #<file-system-label "home">
14064 File system labels are used to refer to file systems by label rather
14065 than by device name. See above for examples.
14068 The @code{(gnu system file-systems)} exports the following useful
14071 @defvr {Scheme Variable} %base-file-systems
14072 These are essential file systems that are required on normal systems,
14073 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
14074 below). Operating system declarations should always contain at least
14078 @defvr {Scheme Variable} %pseudo-terminal-file-system
14079 This is the file system to be mounted as @file{/dev/pts}. It supports
14080 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
14081 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
14082 Manual}). Pseudo-terminals are used by terminal emulators such as
14086 @defvr {Scheme Variable} %shared-memory-file-system
14087 This file system is mounted as @file{/dev/shm} and is used to support
14088 memory sharing across processes (@pxref{Memory-mapped I/O,
14089 @code{shm_open},, libc, The GNU C Library Reference Manual}).
14092 @defvr {Scheme Variable} %immutable-store
14093 This file system performs a read-only ``bind mount'' of
14094 @file{/gnu/store}, making it read-only for all the users including
14095 @code{root}. This prevents against accidental modification by software
14096 running as @code{root} or by system administrators.
14098 The daemon itself is still able to write to the store: it remounts it
14099 read-write in its own ``name space.''
14102 @defvr {Scheme Variable} %binary-format-file-system
14103 The @code{binfmt_misc} file system, which allows handling of arbitrary
14104 executable file types to be delegated to user space. This requires the
14105 @code{binfmt.ko} kernel module to be loaded.
14108 @defvr {Scheme Variable} %fuse-control-file-system
14109 The @code{fusectl} file system, which allows unprivileged users to mount
14110 and unmount user-space FUSE file systems. This requires the
14111 @code{fuse.ko} kernel module to be loaded.
14114 The @code{(gnu system uuid)} module provides tools to deal with file
14115 system ``unique identifiers'' (UUIDs).
14117 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
14118 Return an opaque UUID (unique identifier) object of the given @var{type}
14119 (a symbol) by parsing @var{str} (a string):
14122 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
14123 @result{} #<<uuid> type: dce bv: @dots{}>
14125 (uuid "1234-ABCD" 'fat)
14126 @result{} #<<uuid> type: fat bv: @dots{}>
14129 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
14130 @code{ntfs}, or one of the commonly found synonyms for these.
14132 UUIDs are another way to unambiguously refer to file systems in
14133 operating system configuration. See the examples above.
14137 @node Btrfs file system
14138 @subsection Btrfs file system
14140 The Btrfs has special features, such as subvolumes, that merit being
14141 explained in more details. The following section attempts to cover
14142 basic as well as complex uses of a Btrfs file system with the Guix
14145 In its simplest usage, a Btrfs file system can be described, for
14150 (mount-point "/home")
14152 (device (file-system-label "my-home")))
14155 The example below is more complex, as it makes use of a Btrfs
14156 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
14157 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
14158 dependency on @code{mapped-devices}):
14162 (device (file-system-label "my-btrfs-pool"))
14165 (options "subvol=rootfs")
14166 (dependencies mapped-devices))
14169 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
14170 top level during the early boot, and rely on their configuration to
14171 refer to the correct subvolume path within that top level. The
14172 bootloaders operating in this way typically produce their configuration
14173 on a running system where the Btrfs partitions are already mounted and
14174 where the subvolume information is readily available. As an example,
14175 @command{grub-mkconfig}, the configuration generator command shipped
14176 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
14177 path of a subvolume.
14179 The Guix System produces a bootloader configuration using the operating
14180 system configuration as its sole input; it is therefore necessary to
14181 extract the subvolume name on which @file{/gnu/store} lives (if any)
14182 from that operating system configuration. To better illustrate,
14183 consider a subvolume named 'rootfs' which contains the root file system
14184 data. In such situation, the GRUB bootloader would only see the top
14185 level of the root Btrfs partition, e.g.:
14189 ├── rootfs (subvolume directory)
14190 ├── gnu (normal directory)
14191 ├── store (normal directory)
14195 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
14196 of the kernel, initrd binaries and any other files referred to in the
14197 GRUB configuration that must be found during the early boot.
14199 The next example shows a nested hierarchy of subvolumes and
14204 ├── rootfs (subvolume)
14205 ├── gnu (normal directory)
14206 ├── store (subvolume)
14210 This scenario would work without mounting the 'store' subvolume.
14211 Mounting 'rootfs' is sufficient, since the subvolume name matches its
14212 intended mount point in the file system hierarchy. Alternatively, the
14213 'store' subvolume could be referred to by setting the @code{subvol}
14214 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
14216 Finally, a more contrived example of nested subvolumes:
14220 ├── root-snapshots (subvolume)
14221 ├── root-current (subvolume)
14222 ├── guix-store (subvolume)
14226 Here, the 'guix-store' subvolume doesn't match its intended mount point,
14227 so it is necessary to mount it. The subvolume must be fully specified,
14228 by passing its file name to the @code{subvol} option. To illustrate,
14229 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
14230 a file system declaration such as:
14234 (device (file-system-label "btrfs-pool-1"))
14235 (mount-point "/gnu/store")
14237 (options "subvol=root-snapshots/root-current/guix-store,\
14238 compress-force=zstd,space_cache=v2"))
14241 @node Mapped Devices
14242 @section Mapped Devices
14244 @cindex device mapping
14245 @cindex mapped devices
14246 The Linux kernel has a notion of @dfn{device mapping}: a block device,
14247 such as a hard disk partition, can be @dfn{mapped} into another device,
14248 usually in @code{/dev/mapper/},
14249 with additional processing over the data that flows through
14250 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
14251 concept of a ``mapped device'' and that of a file system: both boil down
14252 to @emph{translating} input/output operations made on a file to
14253 operations on its backing store. Thus, the Hurd implements mapped
14254 devices, like file systems, using the generic @dfn{translator} mechanism
14255 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
14256 typical example is encryption device mapping: all writes to the mapped
14257 device are encrypted, and all reads are deciphered, transparently.
14258 Guix extends this notion by considering any device or set of devices that
14259 are @dfn{transformed} in some way to create a new device; for instance,
14260 RAID devices are obtained by @dfn{assembling} several other devices, such
14261 as hard disks or partitions, into a new one that behaves as one partition.
14263 Mapped devices are declared using the @code{mapped-device} form,
14264 defined as follows; for examples, see below.
14266 @deftp {Data Type} mapped-device
14267 Objects of this type represent device mappings that will be made when
14268 the system boots up.
14272 This is either a string specifying the name of the block device to be mapped,
14273 such as @code{"/dev/sda3"}, or a list of such strings when several devices
14274 need to be assembled for creating a new one. In case of LVM this is a
14275 string specifying name of the volume group to be mapped.
14278 This string specifies the name of the resulting mapped device. For
14279 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
14280 specifying @code{"my-partition"} leads to the creation of
14281 the @code{"/dev/mapper/my-partition"} device.
14282 For RAID devices of type @code{raid-device-mapping}, the full device name
14283 such as @code{"/dev/md0"} needs to be given.
14284 LVM logical volumes of type @code{lvm-device-mapping} need to
14285 be specified as @code{"VGNAME-LVNAME"}.
14288 This list of strings specifies names of the resulting mapped devices in case
14289 there are several. The format is identical to @var{target}.
14292 This must be a @code{mapped-device-kind} object, which specifies how
14293 @var{source} is mapped to @var{target}.
14297 @defvr {Scheme Variable} luks-device-mapping
14298 This defines LUKS block device encryption using the @command{cryptsetup}
14299 command from the package with the same name. It relies on the
14300 @code{dm-crypt} Linux kernel module.
14303 @defvr {Scheme Variable} raid-device-mapping
14304 This defines a RAID device, which is assembled using the @code{mdadm}
14305 command from the package with the same name. It requires a Linux kernel
14306 module for the appropriate RAID level to be loaded, such as @code{raid456}
14307 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
14310 @cindex LVM, logical volume manager
14311 @defvr {Scheme Variable} lvm-device-mapping
14312 This defines one or more logical volumes for the Linux
14313 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
14314 The volume group is activated by the @command{vgchange} command from the
14315 @code{lvm2} package.
14318 @cindex disk encryption
14320 The following example specifies a mapping from @file{/dev/sda3} to
14321 @file{/dev/mapper/home} using LUKS---the
14322 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
14323 standard mechanism for disk encryption.
14324 The @file{/dev/mapper/home}
14325 device can then be used as the @code{device} of a @code{file-system}
14326 declaration (@pxref{File Systems}).
14330 (source "/dev/sda3")
14332 (type luks-device-mapping))
14335 Alternatively, to become independent of device numbering, one may obtain
14336 the LUKS UUID (@dfn{unique identifier}) of the source device by a
14340 cryptsetup luksUUID /dev/sda3
14343 and use it as follows:
14347 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
14349 (type luks-device-mapping))
14352 @cindex swap encryption
14353 It is also desirable to encrypt swap space, since swap space may contain
14354 sensitive data. One way to accomplish that is to use a swap file in a
14355 file system on a device mapped via LUKS encryption. In this way, the
14356 swap file is encrypted because the entire device is encrypted.
14357 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
14359 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
14360 may be declared as follows:
14364 (source (list "/dev/sda1" "/dev/sdb1"))
14365 (target "/dev/md0")
14366 (type raid-device-mapping))
14369 The @file{/dev/md0} device can then be used as the @code{device} of a
14370 @code{file-system} declaration (@pxref{File Systems}).
14371 Note that the RAID level need not be given; it is chosen during the
14372 initial creation and formatting of the RAID device and is determined
14373 automatically later.
14375 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
14376 be declared as follows:
14381 (targets (list "vg0-alpha" "vg0-beta"))
14382 (type lvm-device-mapping))
14385 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14386 then be used as the @code{device} of a @code{file-system} declaration
14387 (@pxref{File Systems}).
14389 @node User Accounts
14390 @section User Accounts
14394 @cindex user accounts
14395 User accounts and groups are entirely managed through the
14396 @code{operating-system} declaration. They are specified with the
14397 @code{user-account} and @code{user-group} forms:
14403 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14404 "audio" ;sound card
14405 "video" ;video devices such as webcams
14406 "cdrom")) ;the good ol' CD-ROM
14407 (comment "Bob's sister"))
14410 Here's a user account that uses a different shell and a custom home
14411 directory (the default would be @file{"/home/bob"}):
14417 (comment "Alice's bro")
14418 (shell (file-append zsh "/bin/zsh"))
14419 (home-directory "/home/robert"))
14422 When booting or upon completion of @command{guix system reconfigure},
14423 the system ensures that only the user accounts and groups specified in
14424 the @code{operating-system} declaration exist, and with the specified
14425 properties. Thus, account or group creations or modifications made by
14426 directly invoking commands such as @command{useradd} are lost upon
14427 reconfiguration or reboot. This ensures that the system remains exactly
14430 @deftp {Data Type} user-account
14431 Objects of this type represent user accounts. The following members may
14436 The name of the user account.
14440 This is the name (a string) or identifier (a number) of the user group
14441 this account belongs to.
14443 @item @code{supplementary-groups} (default: @code{'()})
14444 Optionally, this can be defined as a list of group names that this
14445 account belongs to.
14447 @item @code{uid} (default: @code{#f})
14448 This is the user ID for this account (a number), or @code{#f}. In the
14449 latter case, a number is automatically chosen by the system when the
14450 account is created.
14452 @item @code{comment} (default: @code{""})
14453 A comment about the account, such as the account owner's full name.
14455 @item @code{home-directory}
14456 This is the name of the home directory for the account.
14458 @item @code{create-home-directory?} (default: @code{#t})
14459 Indicates whether the home directory of this account should be created
14460 if it does not exist yet.
14462 @item @code{shell} (default: Bash)
14463 This is a G-expression denoting the file name of a program to be used as
14464 the shell (@pxref{G-Expressions}). For example, you would refer to the
14465 Bash executable like this:
14468 (file-append bash "/bin/bash")
14472 ... and to the Zsh executable like that:
14475 (file-append zsh "/bin/zsh")
14478 @item @code{system?} (default: @code{#f})
14479 This Boolean value indicates whether the account is a ``system''
14480 account. System accounts are sometimes treated specially; for instance,
14481 graphical login managers do not list them.
14483 @anchor{user-account-password}
14484 @cindex password, for user accounts
14485 @item @code{password} (default: @code{#f})
14486 You would normally leave this field to @code{#f}, initialize user
14487 passwords as @code{root} with the @command{passwd} command, and then let
14488 users change it with @command{passwd}. Passwords set with
14489 @command{passwd} are of course preserved across reboot and
14492 If you @emph{do} want to set an initial password for an account, then
14493 this field must contain the encrypted password, as a string. You can use the
14494 @code{crypt} procedure for this purpose:
14501 ;; Specify a SHA-512-hashed initial password.
14502 (password (crypt "InitialPassword!" "$6$abc")))
14506 The hash of this initial password will be available in a file in
14507 @file{/gnu/store}, readable by all the users, so this method must be used with
14511 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14512 more information on password encryption, and @ref{Encryption,,, guile, GNU
14513 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14519 User group declarations are even simpler:
14522 (user-group (name "students"))
14525 @deftp {Data Type} user-group
14526 This type is for, well, user groups. There are just a few fields:
14530 The name of the group.
14532 @item @code{id} (default: @code{#f})
14533 The group identifier (a number). If @code{#f}, a new number is
14534 automatically allocated when the group is created.
14536 @item @code{system?} (default: @code{#f})
14537 This Boolean value indicates whether the group is a ``system'' group.
14538 System groups have low numerical IDs.
14540 @item @code{password} (default: @code{#f})
14541 What, user groups can have a password? Well, apparently yes. Unless
14542 @code{#f}, this field specifies the password of the group.
14547 For convenience, a variable lists all the basic user groups one may
14550 @defvr {Scheme Variable} %base-groups
14551 This is the list of basic user groups that users and/or packages expect
14552 to be present on the system. This includes groups such as ``root'',
14553 ``wheel'', and ``users'', as well as groups used to control access to
14554 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14557 @defvr {Scheme Variable} %base-user-accounts
14558 This is the list of basic system accounts that programs may expect to
14559 find on a GNU/Linux system, such as the ``nobody'' account.
14561 Note that the ``root'' account is not included here. It is a
14562 special-case and is automatically added whether or not it is specified.
14565 @node Keyboard Layout
14566 @section Keyboard Layout
14568 @cindex keyboard layout
14570 To specify what each key of your keyboard does, you need to tell the operating
14571 system what @dfn{keyboard layout} you want to use. The default, when nothing
14572 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14573 However, German speakers will usually prefer the German QWERTZ layout, French
14574 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14575 or bépo, and they might even want to further customize the effect of some of
14576 the keys. This section explains how to get that done.
14578 @cindex keyboard layout, definition
14579 There are three components that will want to know about your keyboard layout:
14583 The @emph{bootloader} may want to know what keyboard layout you want to use
14584 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14585 you want, for instance, to make sure that you can type the passphrase of your
14586 encrypted root partition using the right layout.
14589 The @emph{operating system kernel}, Linux, will need that so that the console
14590 is properly configured (@pxref{operating-system Reference,
14591 @code{keyboard-layout}}).
14594 The @emph{graphical display server}, usually Xorg, also has its own idea of
14595 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14598 Guix allows you to configure all three separately but, fortunately, it allows
14599 you to share the same keyboard layout for all three components.
14601 @cindex XKB, keyboard layouts
14602 Keyboard layouts are represented by records created by the
14603 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14604 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14605 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14606 optional variant name, an optional keyboard model name, and a possibly empty
14607 list of additional options. In most cases the layout name is all you care
14610 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14611 [#:model] [#:options '()]
14612 Return a new keyboard layout with the given @var{name} and @var{variant}.
14614 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14615 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14616 @code{xkeyboard-config} package for valid options.
14619 Here are a few examples:
14622 ;; The German QWERTZ layout. Here we assume a standard
14623 ;; "pc105" keyboard model.
14624 (keyboard-layout "de")
14626 ;; The bépo variant of the French layout.
14627 (keyboard-layout "fr" "bepo")
14629 ;; The Catalan layout.
14630 (keyboard-layout "es" "cat")
14632 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14633 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14635 ;; The Latin American Spanish layout. In addition, the
14636 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14637 ;; and the "Menu" key is used as a "Compose" key to enter
14638 ;; accented letters.
14639 (keyboard-layout "latam"
14640 #:options '("ctrl:nocaps" "compose:menu"))
14642 ;; The Russian layout for a ThinkPad keyboard.
14643 (keyboard-layout "ru" #:model "thinkpad")
14645 ;; The "US international" layout, which is the US layout plus
14646 ;; dead keys to enter accented characters. This is for an
14647 ;; Apple MacBook keyboard.
14648 (keyboard-layout "us" "intl" #:model "macbook78")
14651 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14652 for a complete list of supported layouts, variants, and models.
14654 @cindex keyboard layout, configuration
14655 Let's say you want your system to use the Turkish keyboard layout throughout
14656 your system---bootloader, console, and Xorg. Here's what your system
14657 configuration would look like:
14659 @findex set-xorg-configuration
14661 ;; Using the Turkish layout for the bootloader, the console,
14666 (keyboard-layout (keyboard-layout "tr")) ;for the console
14667 (bootloader (bootloader-configuration
14668 (bootloader grub-efi-bootloader)
14669 (target "/boot/efi")
14670 (keyboard-layout keyboard-layout))) ;for GRUB
14671 (services (cons (set-xorg-configuration
14672 (xorg-configuration ;for Xorg
14673 (keyboard-layout keyboard-layout)))
14674 %desktop-services)))
14677 In the example above, for GRUB and for Xorg, we just refer to the
14678 @code{keyboard-layout} field defined above, but we could just as well refer to
14679 a different layout. The @code{set-xorg-configuration} procedure communicates
14680 the desired Xorg configuration to the graphical log-in manager, by default
14683 We've discussed how to specify the @emph{default} keyboard layout of your
14684 system when it starts, but you can also adjust it at run time:
14688 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14689 where you can select one or more keyboard layouts.
14692 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14693 allows you to change the current layout. For example, this is how you would
14694 change the layout to US Dvorak:
14697 setxkbmap us dvorak
14701 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14702 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14703 keyboard layout categorization described above. The command below loads the
14704 French bépo layout:
14715 A @dfn{locale} defines cultural conventions for a particular language
14716 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14717 Reference Manual}). Each locale has a name that typically has the form
14718 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14719 @code{fr_LU.utf8} designates the locale for the French language, with
14720 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14722 @cindex locale definition
14723 Usually, you will want to specify the default locale for the machine
14724 using the @code{locale} field of the @code{operating-system} declaration
14725 (@pxref{operating-system Reference, @code{locale}}).
14727 The selected locale is automatically added to the @dfn{locale
14728 definitions} known to the system if needed, with its codeset inferred
14729 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14730 @code{UTF-8} codeset. Additional locale definitions can be specified in
14731 the @code{locale-definitions} slot of @code{operating-system}---this is
14732 useful, for instance, if the codeset could not be inferred from the
14733 locale name. The default set of locale definitions includes some widely
14734 used locales, but not all the available locales, in order to save space.
14736 For instance, to add the North Frisian locale for Germany, the value of
14740 (cons (locale-definition
14741 (name "fy_DE.utf8") (source "fy_DE"))
14742 %default-locale-definitions)
14745 Likewise, to save space, one might want @code{locale-definitions} to
14746 list only the locales that are actually used, as in:
14749 (list (locale-definition
14750 (name "ja_JP.eucjp") (source "ja_JP")
14751 (charset "EUC-JP")))
14755 The compiled locale definitions are available at
14756 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14757 version, which is the default location where the GNU@tie{}libc provided
14758 by Guix looks for locale data. This can be overridden using the
14759 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14760 @env{LOCPATH} and locale packages}).
14762 The @code{locale-definition} form is provided by the @code{(gnu system
14763 locale)} module. Details are given below.
14765 @deftp {Data Type} locale-definition
14766 This is the data type of a locale definition.
14771 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14772 Reference Manual}, for more information on locale names.
14774 @item @code{source}
14775 The name of the source for that locale. This is typically the
14776 @code{@var{language}_@var{territory}} part of the locale name.
14778 @item @code{charset} (default: @code{"UTF-8"})
14779 The ``character set'' or ``code set'' for that locale,
14780 @uref{https://www.iana.org/assignments/character-sets, as defined by
14786 @defvr {Scheme Variable} %default-locale-definitions
14787 A list of commonly used UTF-8 locales, used as the default
14788 value of the @code{locale-definitions} field of @code{operating-system}
14791 @cindex locale name
14792 @cindex normalized codeset in locale names
14793 These locale definitions use the @dfn{normalized codeset} for the part
14794 that follows the dot in the name (@pxref{Using gettextized software,
14795 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14796 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14797 @code{uk_UA.UTF-8}.
14800 @subsection Locale Data Compatibility Considerations
14802 @cindex incompatibility, of locale data
14803 @code{operating-system} declarations provide a @code{locale-libcs} field
14804 to specify the GNU@tie{}libc packages that are used to compile locale
14805 declarations (@pxref{operating-system Reference}). ``Why would I
14806 care?'', you may ask. Well, it turns out that the binary format of
14807 locale data is occasionally incompatible from one libc version to
14810 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14811 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14812 For instance, a program linked against libc version 2.21 is unable to
14813 read locale data produced with libc 2.22; worse, that program
14814 @emph{aborts} instead of simply ignoring the incompatible locale
14815 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14816 the incompatible locale data, which is already an improvement.}.
14817 Similarly, a program linked against libc 2.22 can read most, but not
14818 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14819 data is incompatible); thus calls to @code{setlocale} may fail, but
14820 programs will not abort.
14822 The ``problem'' with Guix is that users have a lot of freedom: They can
14823 choose whether and when to upgrade software in their profiles, and might
14824 be using a libc version different from the one the system administrator
14825 used to build the system-wide locale data.
14827 Fortunately, unprivileged users can also install their own locale data
14828 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14829 @env{GUIX_LOCPATH} and locale packages}).
14831 Still, it is best if the system-wide locale data at
14832 @file{/run/current-system/locale} is built for all the libc versions
14833 actually in use on the system, so that all the programs can access
14834 it---this is especially crucial on a multi-user system. To do that, the
14835 administrator can specify several libc packages in the
14836 @code{locale-libcs} field of @code{operating-system}:
14839 (use-package-modules base)
14843 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14846 This example would lead to a system containing locale definitions for
14847 both libc 2.21 and the current version of libc in
14848 @file{/run/current-system/locale}.
14854 @cindex system services
14855 An important part of preparing an @code{operating-system} declaration is
14856 listing @dfn{system services} and their configuration (@pxref{Using the
14857 Configuration System}). System services are typically daemons launched
14858 when the system boots, or other actions needed at that time---e.g.,
14859 configuring network access.
14861 Guix has a broad definition of ``service'' (@pxref{Service
14862 Composition}), but many services are managed by the GNU@tie{}Shepherd
14863 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14864 command allows you to list the available services, show their status,
14865 start and stop them, or do other specific operations (@pxref{Jump
14866 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14872 The above command, run as @code{root}, lists the currently defined
14873 services. The @command{herd doc} command shows a synopsis of the given
14874 service and its associated actions:
14878 Run libc's name service cache daemon (nscd).
14880 # herd doc nscd action invalidate
14881 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14884 The @command{start}, @command{stop}, and @command{restart} sub-commands
14885 have the effect you would expect. For instance, the commands below stop
14886 the nscd service and restart the Xorg display server:
14890 Service nscd has been stopped.
14891 # herd restart xorg-server
14892 Service xorg-server has been stopped.
14893 Service xorg-server has been started.
14896 The following sections document the available services, starting with
14897 the core services, that may be used in an @code{operating-system}
14901 * Base Services:: Essential system services.
14902 * Scheduled Job Execution:: The mcron service.
14903 * Log Rotation:: The rottlog service.
14904 * Networking Services:: Network setup, SSH daemon, etc.
14905 * Unattended Upgrades:: Automated system upgrades.
14906 * X Window:: Graphical display.
14907 * Printing Services:: Local and remote printer support.
14908 * Desktop Services:: D-Bus and desktop services.
14909 * Sound Services:: ALSA and Pulseaudio services.
14910 * Database Services:: SQL databases, key-value stores, etc.
14911 * Mail Services:: IMAP, POP3, SMTP, and all that.
14912 * Messaging Services:: Messaging services.
14913 * Telephony Services:: Telephony services.
14914 * File-Sharing Services:: File-sharing services.
14915 * Monitoring Services:: Monitoring services.
14916 * Kerberos Services:: Kerberos services.
14917 * LDAP Services:: LDAP services.
14918 * Web Services:: Web servers.
14919 * Certificate Services:: TLS certificates via Let's Encrypt.
14920 * DNS Services:: DNS daemons.
14921 * VPN Services:: VPN daemons.
14922 * Network File System:: NFS related services.
14923 * Continuous Integration:: Cuirass and Laminar services.
14924 * Power Management Services:: Extending battery life.
14925 * Audio Services:: The MPD.
14926 * Virtualization Services:: Virtualization services.
14927 * Version Control Services:: Providing remote access to Git repositories.
14928 * Game Services:: Game servers.
14929 * PAM Mount Service:: Service to mount volumes when logging in.
14930 * Guix Services:: Services relating specifically to Guix.
14931 * Linux Services:: Services tied to the Linux kernel.
14932 * Hurd Services:: Services specific for a Hurd System.
14933 * Miscellaneous Services:: Other services.
14936 @node Base Services
14937 @subsection Base Services
14939 The @code{(gnu services base)} module provides definitions for the basic
14940 services that one expects from the system. The services exported by
14941 this module are listed below.
14943 @defvr {Scheme Variable} %base-services
14944 This variable contains a list of basic services (@pxref{Service Types
14945 and Services}, for more information on service objects) one would
14946 expect from the system: a login service (mingetty) on each tty, syslogd,
14947 the libc name service cache daemon (nscd), the udev device manager, and
14950 This is the default value of the @code{services} field of
14951 @code{operating-system} declarations. Usually, when customizing a
14952 system, you will want to append services to @code{%base-services}, like
14956 (append (list (service avahi-service-type)
14957 (service openssh-service-type))
14962 @defvr {Scheme Variable} special-files-service-type
14963 This is the service that sets up ``special files'' such as
14964 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14966 The value associated with @code{special-files-service-type} services
14967 must be a list of tuples where the first element is the ``special file''
14968 and the second element is its target. By default it is:
14970 @cindex @file{/bin/sh}
14971 @cindex @file{sh}, in @file{/bin}
14973 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14976 @cindex @file{/usr/bin/env}
14977 @cindex @file{env}, in @file{/usr/bin}
14978 If you want to add, say, @code{/usr/bin/env} to your system, you can
14982 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14983 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14986 Since this is part of @code{%base-services}, you can use
14987 @code{modify-services} to customize the set of special files
14988 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14989 to add a special file is @i{via} the @code{extra-special-file} procedure
14993 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14994 Use @var{target} as the ``special file'' @var{file}.
14996 For example, adding the following lines to the @code{services} field of
14997 your operating system declaration leads to a @file{/usr/bin/env}
15001 (extra-special-file "/usr/bin/env"
15002 (file-append coreutils "/bin/env"))
15006 @deffn {Scheme Procedure} host-name-service @var{name}
15007 Return a service that sets the host name to @var{name}.
15010 @defvr {Scheme Variable} console-font-service-type
15011 Install the given fonts on the specified ttys (fonts are per
15012 virtual console on the kernel Linux). The value of this service is a list of
15013 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
15014 package or any valid argument to @command{setfont}, as in this example:
15017 `(("tty1" . "LatGrkCyr-8x16")
15018 ("tty2" . ,(file-append
15020 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
15021 ("tty3" . ,(file-append
15023 "/share/consolefonts/ter-132n"))) ; for HDPI
15027 @deffn {Scheme Procedure} login-service @var{config}
15028 Return a service to run login according to @var{config}, a
15029 @code{<login-configuration>} object, which specifies the message of the day,
15030 among other things.
15033 @deftp {Data Type} login-configuration
15034 This is the data type representing the configuration of login.
15039 @cindex message of the day
15040 A file-like object containing the ``message of the day''.
15042 @item @code{allow-empty-passwords?} (default: @code{#t})
15043 Allow empty passwords by default so that first-time users can log in when
15044 the 'root' account has just been created.
15049 @deffn {Scheme Procedure} mingetty-service @var{config}
15050 Return a service to run mingetty according to @var{config}, a
15051 @code{<mingetty-configuration>} object, which specifies the tty to run, among
15055 @deftp {Data Type} mingetty-configuration
15056 This is the data type representing the configuration of Mingetty, which
15057 provides the default implementation of virtual console log-in.
15062 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
15064 @item @code{auto-login} (default: @code{#f})
15065 When true, this field must be a string denoting the user name under
15066 which the system automatically logs in. When it is @code{#f}, a
15067 user name and password must be entered to log in.
15069 @item @code{login-program} (default: @code{#f})
15070 This must be either @code{#f}, in which case the default log-in program
15071 is used (@command{login} from the Shadow tool suite), or a gexp denoting
15072 the name of the log-in program.
15074 @item @code{login-pause?} (default: @code{#f})
15075 When set to @code{#t} in conjunction with @var{auto-login}, the user
15076 will have to press a key before the log-in shell is launched.
15078 @item @code{clear-on-logout?} (default: @code{#t})
15079 When set to @code{#t}, the screen will be cleared after logout.
15081 @item @code{mingetty} (default: @var{mingetty})
15082 The Mingetty package to use.
15087 @deffn {Scheme Procedure} agetty-service @var{config}
15088 Return a service to run agetty according to @var{config}, an
15089 @code{<agetty-configuration>} object, which specifies the tty to run,
15090 among other things.
15093 @deftp {Data Type} agetty-configuration
15094 This is the data type representing the configuration of agetty, which
15095 implements virtual and serial console log-in. See the @code{agetty(8)}
15096 man page for more information.
15101 The name of the console this agetty runs on, as a string---e.g.,
15102 @code{"ttyS0"}. This argument is optional, it will default to
15103 a reasonable default serial port used by the kernel Linux.
15105 For this, if there is a value for an option @code{agetty.tty} in the kernel
15106 command line, agetty will extract the device name of the serial port
15107 from it and use that.
15109 If not and if there is a value for an option @code{console} with a tty in
15110 the Linux command line, agetty will extract the device name of the
15111 serial port from it and use that.
15113 In both cases, agetty will leave the other serial device settings
15114 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
15117 @item @code{baud-rate} (default: @code{#f})
15118 A string containing a comma-separated list of one or more baud rates, in
15121 @item @code{term} (default: @code{#f})
15122 A string containing the value used for the @env{TERM} environment
15125 @item @code{eight-bits?} (default: @code{#f})
15126 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
15129 @item @code{auto-login} (default: @code{#f})
15130 When passed a login name, as a string, the specified user will be logged
15131 in automatically without prompting for their login name or password.
15133 @item @code{no-reset?} (default: @code{#f})
15134 When @code{#t}, don't reset terminal cflags (control modes).
15136 @item @code{host} (default: @code{#f})
15137 This accepts a string containing the ``login_host'', which will be written
15138 into the @file{/var/run/utmpx} file.
15140 @item @code{remote?} (default: @code{#f})
15141 When set to @code{#t} in conjunction with @var{host}, this will add an
15142 @code{-r} fakehost option to the command line of the login program
15143 specified in @var{login-program}.
15145 @item @code{flow-control?} (default: @code{#f})
15146 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
15148 @item @code{no-issue?} (default: @code{#f})
15149 When set to @code{#t}, the contents of the @file{/etc/issue} file will
15150 not be displayed before presenting the login prompt.
15152 @item @code{init-string} (default: @code{#f})
15153 This accepts a string that will be sent to the tty or modem before
15154 sending anything else. It can be used to initialize a modem.
15156 @item @code{no-clear?} (default: @code{#f})
15157 When set to @code{#t}, agetty will not clear the screen before showing
15160 @item @code{login-program} (default: (file-append shadow "/bin/login"))
15161 This must be either a gexp denoting the name of a log-in program, or
15162 unset, in which case the default value is the @command{login} from the
15165 @item @code{local-line} (default: @code{#f})
15166 Control the CLOCAL line flag. This accepts one of three symbols as
15167 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
15168 the default value chosen by agetty is @code{'auto}.
15170 @item @code{extract-baud?} (default: @code{#f})
15171 When set to @code{#t}, instruct agetty to try to extract the baud rate
15172 from the status messages produced by certain types of modems.
15174 @item @code{skip-login?} (default: @code{#f})
15175 When set to @code{#t}, do not prompt the user for a login name. This
15176 can be used with @var{login-program} field to use non-standard login
15179 @item @code{no-newline?} (default: @code{#f})
15180 When set to @code{#t}, do not print a newline before printing the
15181 @file{/etc/issue} file.
15183 @c Is this dangerous only when used with login-program, or always?
15184 @item @code{login-options} (default: @code{#f})
15185 This option accepts a string containing options that are passed to the
15186 login program. When used with the @var{login-program}, be aware that a
15187 malicious user could try to enter a login name containing embedded
15188 options that could be parsed by the login program.
15190 @item @code{login-pause} (default: @code{#f})
15191 When set to @code{#t}, wait for any key before showing the login prompt.
15192 This can be used in conjunction with @var{auto-login} to save memory by
15193 lazily spawning shells.
15195 @item @code{chroot} (default: @code{#f})
15196 Change root to the specified directory. This option accepts a directory
15199 @item @code{hangup?} (default: @code{#f})
15200 Use the Linux system call @code{vhangup} to do a virtual hangup of the
15201 specified terminal.
15203 @item @code{keep-baud?} (default: @code{#f})
15204 When set to @code{#t}, try to keep the existing baud rate. The baud
15205 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
15208 @item @code{timeout} (default: @code{#f})
15209 When set to an integer value, terminate if no user name could be read
15210 within @var{timeout} seconds.
15212 @item @code{detect-case?} (default: @code{#f})
15213 When set to @code{#t}, turn on support for detecting an uppercase-only
15214 terminal. This setting will detect a login name containing only
15215 uppercase letters as indicating an uppercase-only terminal and turn on
15216 some upper-to-lower case conversions. Note that this will not support
15217 Unicode characters.
15219 @item @code{wait-cr?} (default: @code{#f})
15220 When set to @code{#t}, wait for the user or modem to send a
15221 carriage-return or linefeed character before displaying
15222 @file{/etc/issue} or login prompt. This is typically used with the
15223 @var{init-string} option.
15225 @item @code{no-hints?} (default: @code{#f})
15226 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
15229 @item @code{no-hostname?} (default: @code{#f})
15230 By default, the hostname is printed. When this option is set to
15231 @code{#t}, no hostname will be shown at all.
15233 @item @code{long-hostname?} (default: @code{#f})
15234 By default, the hostname is only printed until the first dot. When this
15235 option is set to @code{#t}, the fully qualified hostname by
15236 @code{gethostname} or @code{getaddrinfo} is shown.
15238 @item @code{erase-characters} (default: @code{#f})
15239 This option accepts a string of additional characters that should be
15240 interpreted as backspace when the user types their login name.
15242 @item @code{kill-characters} (default: @code{#f})
15243 This option accepts a string that should be interpreted to mean ``ignore
15244 all previous characters'' (also called a ``kill'' character) when the user
15245 types their login name.
15247 @item @code{chdir} (default: @code{#f})
15248 This option accepts, as a string, a directory path that will be changed
15251 @item @code{delay} (default: @code{#f})
15252 This options accepts, as an integer, the number of seconds to sleep
15253 before opening the tty and displaying the login prompt.
15255 @item @code{nice} (default: @code{#f})
15256 This option accepts, as an integer, the nice value with which to run the
15257 @command{login} program.
15259 @item @code{extra-options} (default: @code{'()})
15260 This option provides an ``escape hatch'' for the user to provide arbitrary
15261 command-line arguments to @command{agetty} as a list of strings.
15266 @deffn {Scheme Procedure} kmscon-service-type @var{config}
15267 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
15268 according to @var{config}, a @code{<kmscon-configuration>} object, which
15269 specifies the tty to run, among other things.
15272 @deftp {Data Type} kmscon-configuration
15273 This is the data type representing the configuration of Kmscon, which
15274 implements virtual console log-in.
15278 @item @code{virtual-terminal}
15279 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
15281 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
15282 A gexp denoting the name of the log-in program. The default log-in program is
15283 @command{login} from the Shadow tool suite.
15285 @item @code{login-arguments} (default: @code{'("-p")})
15286 A list of arguments to pass to @command{login}.
15288 @item @code{auto-login} (default: @code{#f})
15289 When passed a login name, as a string, the specified user will be logged
15290 in automatically without prompting for their login name or password.
15292 @item @code{hardware-acceleration?} (default: #f)
15293 Whether to use hardware acceleration.
15295 @item @code{font-engine} (default: @code{"pango"})
15296 Font engine used in Kmscon.
15298 @item @code{font-size} (default: @code{12})
15299 Font size used in Kmscon.
15301 @item @code{keyboard-layout} (default: @code{#f})
15302 If this is @code{#f}, Kmscon uses the default keyboard layout---usually US
15303 English (``qwerty'') for a 105-key PC keyboard.
15305 Otherwise this must be a @code{keyboard-layout} object specifying the
15306 keyboard layout. @xref{Keyboard Layout}, for more information on how to
15307 specify the keyboard layout.
15309 @item @code{kmscon} (default: @var{kmscon})
15310 The Kmscon package to use.
15315 @cindex name service cache daemon
15317 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
15318 [#:name-services '()]
15319 Return a service that runs the libc name service cache daemon (nscd) with the
15320 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
15321 Service Switch}, for an example.
15323 For convenience, the Shepherd service for nscd provides the following actions:
15327 @cindex cache invalidation, nscd
15328 @cindex nscd, cache invalidation
15329 This invalidate the given cache. For instance, running:
15332 herd invalidate nscd hosts
15336 invalidates the host name lookup cache of nscd.
15339 Running @command{herd statistics nscd} displays information about nscd usage
15345 @defvr {Scheme Variable} %nscd-default-configuration
15346 This is the default @code{<nscd-configuration>} value (see below) used
15347 by @code{nscd-service}. It uses the caches defined by
15348 @code{%nscd-default-caches}; see below.
15351 @deftp {Data Type} nscd-configuration
15352 This is the data type representing the name service cache daemon (nscd)
15357 @item @code{name-services} (default: @code{'()})
15358 List of packages denoting @dfn{name services} that must be visible to
15359 the nscd---e.g., @code{(list @var{nss-mdns})}.
15361 @item @code{glibc} (default: @var{glibc})
15362 Package object denoting the GNU C Library providing the @command{nscd}
15365 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
15366 Name of the nscd log file. This is where debugging output goes when
15367 @code{debug-level} is strictly positive.
15369 @item @code{debug-level} (default: @code{0})
15370 Integer denoting the debugging levels. Higher numbers mean that more
15371 debugging output is logged.
15373 @item @code{caches} (default: @code{%nscd-default-caches})
15374 List of @code{<nscd-cache>} objects denoting things to be cached; see
15380 @deftp {Data Type} nscd-cache
15381 Data type representing a cache database of nscd and its parameters.
15385 @item @code{database}
15386 This is a symbol representing the name of the database to be cached.
15387 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
15388 @code{services}, which designate the corresponding NSS database
15389 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
15391 @item @code{positive-time-to-live}
15392 @itemx @code{negative-time-to-live} (default: @code{20})
15393 A number representing the number of seconds during which a positive or
15394 negative lookup result remains in cache.
15396 @item @code{check-files?} (default: @code{#t})
15397 Whether to check for updates of the files corresponding to
15400 For instance, when @var{database} is @code{hosts}, setting this flag
15401 instructs nscd to check for updates in @file{/etc/hosts} and to take
15404 @item @code{persistent?} (default: @code{#t})
15405 Whether the cache should be stored persistently on disk.
15407 @item @code{shared?} (default: @code{#t})
15408 Whether the cache should be shared among users.
15410 @item @code{max-database-size} (default: 32@tie{}MiB)
15411 Maximum size in bytes of the database cache.
15413 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15414 @c settings, so leave them out.
15419 @defvr {Scheme Variable} %nscd-default-caches
15420 List of @code{<nscd-cache>} objects used by default by
15421 @code{nscd-configuration} (see above).
15423 It enables persistent and aggressive caching of service and host name
15424 lookups. The latter provides better host name lookup performance,
15425 resilience in the face of unreliable name servers, and also better
15426 privacy---often the result of host name lookups is in local cache, so
15427 external name servers do not even need to be queried.
15430 @anchor{syslog-configuration-type}
15433 @deftp {Data Type} syslog-configuration
15434 This data type represents the configuration of the syslog daemon.
15437 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15438 The syslog daemon to use.
15440 @item @code{config-file} (default: @code{%default-syslog.conf})
15441 The syslog configuration file to use.
15446 @anchor{syslog-service}
15448 @deffn {Scheme Procedure} syslog-service @var{config}
15449 Return a service that runs a syslog daemon according to @var{config}.
15451 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15452 information on the configuration file syntax.
15455 @defvr {Scheme Variable} guix-service-type
15456 This is the type of the service that runs the build daemon,
15457 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15458 @code{guix-configuration} record as described below.
15461 @anchor{guix-configuration-type}
15462 @deftp {Data Type} guix-configuration
15463 This data type represents the configuration of the Guix build daemon.
15464 @xref{Invoking guix-daemon}, for more information.
15467 @item @code{guix} (default: @var{guix})
15468 The Guix package to use.
15470 @item @code{build-group} (default: @code{"guixbuild"})
15471 Name of the group for build user accounts.
15473 @item @code{build-accounts} (default: @code{10})
15474 Number of build user accounts to create.
15476 @item @code{authorize-key?} (default: @code{#t})
15477 @cindex substitutes, authorization thereof
15478 Whether to authorize the substitute keys listed in
15479 @code{authorized-keys}---by default that of
15480 @code{@value{SUBSTITUTE-SERVER-1}} and
15481 @code{@value{SUBSTITUTE-SERVER-2}}
15482 (@pxref{Substitutes}).
15484 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15485 changed by invoking @command{guix archive --authorize}. You must
15486 instead adjust @code{guix-configuration} as you wish and reconfigure the
15487 system. This ensures that your operating system configuration file is
15491 When booting or reconfiguring to a system where @code{authorize-key?}
15492 is true, the existing @file{/etc/guix/acl} file is backed up as
15493 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15494 file. This is to facilitate migration from earlier versions, which
15495 allowed for in-place modifications to @file{/etc/guix/acl}.
15498 @vindex %default-authorized-guix-keys
15499 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15500 The list of authorized key files for archive imports, as a list of
15501 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15502 contains that of @code{@value{SUBSTITUTE-SERVER-1}} and
15503 @code{@value{SUBSTITUTE-SERVER-2}} (@pxref{Substitutes}). See
15504 @code{substitute-urls} below for an example on how to change it.
15506 @item @code{use-substitutes?} (default: @code{#t})
15507 Whether to use substitutes.
15509 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15510 The list of URLs where to look for substitutes by default.
15512 Suppose you would like to fetch substitutes from @code{guix.example.org}
15513 in addition to @code{@value{SUBSTITUTE-SERVER-1}}. You will need to do
15514 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15515 and (2) authorize its signing key, having done appropriate checks
15516 (@pxref{Substitute Server Authorization}). The configuration below does
15520 (guix-configuration
15522 (append (list "https://guix.example.org")
15523 %default-substitute-urls))
15525 (append (list (local-file "./guix.example.org-key.pub"))
15526 %default-authorized-guix-keys)))
15529 This example assumes that the file @file{./guix.example.org-key.pub}
15530 contains the public key that @code{guix.example.org} uses to sign
15533 @item @code{max-silent-time} (default: @code{0})
15534 @itemx @code{timeout} (default: @code{0})
15535 The number of seconds of silence and the number of seconds of activity,
15536 respectively, after which a build process times out. A value of zero
15537 disables the timeout.
15539 @item @code{log-compression} (default: @code{'bzip2})
15540 The type of compression used for build logs---one of @code{gzip},
15541 @code{bzip2}, or @code{none}.
15543 @item @code{discover?} (default: @code{#f})
15544 Whether to discover substitute servers on the local network using mDNS
15547 @item @code{extra-options} (default: @code{'()})
15548 List of extra command-line options for @command{guix-daemon}.
15550 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15551 File where @command{guix-daemon}'s standard output and standard error
15554 @cindex HTTP proxy, for @code{guix-daemon}
15555 @cindex proxy, for @code{guix-daemon} HTTP access
15556 @item @code{http-proxy} (default: @code{#f})
15557 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15558 derivations and substitutes.
15560 It is also possible to change the daemon's proxy at run time through the
15561 @code{set-http-proxy} action, which restarts it:
15564 herd set-http-proxy guix-daemon http://localhost:8118
15567 To clear the proxy settings, run:
15570 herd set-http-proxy guix-daemon
15573 @item @code{tmpdir} (default: @code{#f})
15574 A directory path where the @command{guix-daemon} will perform builds.
15579 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15580 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15581 udev rules can be provided as a list of files through the @var{rules}
15582 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15583 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15584 creation of such rule files.
15586 The @command{herd rules udev} command, as root, returns the name of the
15587 directory containing all the active udev rules.
15590 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15591 Return a udev-rule file named @var{file-name} containing the rules
15592 defined by the @var{contents} literal.
15594 In the following example, a rule for a USB device is defined to be
15595 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15596 upon detecting a USB device with a given product identifier.
15599 (define %example-udev-rule
15601 "90-usb-thing.rules"
15602 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15603 "ATTR@{product@}==\"Example\", "
15604 "RUN+=\"/path/to/script\"")))
15608 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15609 [#:groups @var{groups}]
15610 Return a service that extends @code{udev-service-type } with @var{rules}
15611 and @code{account-service-type} with @var{groups} as system groups.
15612 This works by creating a singleton service type
15613 @code{@var{name}-udev-rules}, of which the returned service is an
15616 Here we show how it can be used to extend @code{udev-service-type} with the
15617 previously defined rule @code{%example-udev-rule}.
15623 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15624 %desktop-services)))
15628 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15629 Return a udev file named @var{file-name} containing the rules defined
15630 within @var{file}, a file-like object.
15632 The following example showcases how we can use an existing rule file.
15635 (use-modules (guix download) ;for url-fetch
15636 (guix packages) ;for origin
15639 (define %android-udev-rules
15641 "51-android-udev.rules"
15642 (let ((version "20170910"))
15645 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15646 "android-udev-rules/" version "/51-android.rules"))
15648 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15652 Additionally, Guix package definitions can be included in @var{rules} in
15653 order to extend the udev rules with the definitions found under their
15654 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15655 @var{file->udev-rule} example, we could have used the
15656 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15657 packages android)} module.
15659 The following example shows how to use the @var{android-udev-rules}
15660 package so that the Android tool @command{adb} can detect devices
15661 without root privileges. It also details how to create the
15662 @code{adbusers} group, which is required for the proper functioning of
15663 the rules defined within the @code{android-udev-rules} package. To
15664 create such a group, we must define it both as part of the
15665 @code{supplementary-groups} of our @code{user-account} declaration, as
15666 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15669 (use-modules (gnu packages android) ;for android-udev-rules
15670 (gnu system shadow) ;for user-group
15675 (users (cons (user-account
15677 (supplementary-groups
15678 '("adbusers" ;for adb
15679 "wheel" "netdev" "audio" "video")))))
15682 (cons (udev-rules-service 'android android-udev-rules
15683 #:groups '("adbusers"))
15684 %desktop-services)))
15687 @defvr {Scheme Variable} urandom-seed-service-type
15688 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15689 when rebooting. It also tries to seed @file{/dev/urandom} from
15690 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15694 @defvr {Scheme Variable} %random-seed-file
15695 This is the name of the file where some random bytes are saved by
15696 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15697 It defaults to @file{/var/lib/random-seed}.
15702 @defvr {Scheme Variable} gpm-service-type
15703 This is the type of the service that runs GPM, the @dfn{general-purpose
15704 mouse daemon}, which provides mouse support to the Linux console. GPM
15705 allows users to use the mouse in the console, notably to select, copy,
15708 The value for services of this type must be a @code{gpm-configuration}
15709 (see below). This service is not part of @code{%base-services}.
15712 @deftp {Data Type} gpm-configuration
15713 Data type representing the configuration of GPM.
15716 @item @code{options} (default: @code{%default-gpm-options})
15717 Command-line options passed to @command{gpm}. The default set of
15718 options instruct @command{gpm} to listen to mouse events on
15719 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15722 @item @code{gpm} (default: @code{gpm})
15723 The GPM package to use.
15728 @anchor{guix-publish-service-type}
15729 @deffn {Scheme Variable} guix-publish-service-type
15730 This is the service type for @command{guix publish} (@pxref{Invoking
15731 guix publish}). Its value must be a @code{guix-publish-configuration}
15732 object, as described below.
15734 This assumes that @file{/etc/guix} already contains a signing key pair as
15735 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15736 archive}). If that is not the case, the service will fail to start.
15739 @deftp {Data Type} guix-publish-configuration
15740 Data type representing the configuration of the @code{guix publish}
15744 @item @code{guix} (default: @code{guix})
15745 The Guix package to use.
15747 @item @code{port} (default: @code{80})
15748 The TCP port to listen for connections.
15750 @item @code{host} (default: @code{"localhost"})
15751 The host (and thus, network interface) to listen to. Use
15752 @code{"0.0.0.0"} to listen on all the network interfaces.
15754 @item @code{advertise?} (default: @code{#f})
15755 When true, advertise the service on the local network @i{via} the DNS-SD
15756 protocol, using Avahi.
15758 This allows neighboring Guix devices with discovery on (see
15759 @code{guix-configuration} above) to discover this @command{guix publish}
15760 instance and to automatically download substitutes from it.
15762 @item @code{compression} (default: @code{'(("gzip" 3) ("zstd" 3))})
15763 This is a list of compression method/level tuple used when compressing
15764 substitutes. For example, to compress all substitutes with @emph{both} lzip
15765 at level 7 and gzip at level 9, write:
15768 '(("lzip" 7) ("gzip" 9))
15771 Level 9 achieves the best compression ratio at the expense of increased CPU
15772 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
15773 publish}, for more information on the available compression methods and
15774 the tradeoffs involved.
15776 An empty list disables compression altogether.
15778 @item @code{nar-path} (default: @code{"nar"})
15779 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15780 publish, @option{--nar-path}}, for details.
15782 @item @code{cache} (default: @code{#f})
15783 When it is @code{#f}, disable caching and instead generate archives on
15784 demand. Otherwise, this should be the name of a directory---e.g.,
15785 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15786 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15787 @option{--cache}}, for more information on the tradeoffs involved.
15789 @item @code{workers} (default: @code{#f})
15790 When it is an integer, this is the number of worker threads used for
15791 caching; when @code{#f}, the number of processors is used.
15792 @xref{Invoking guix publish, @option{--workers}}, for more information.
15794 @item @code{cache-bypass-threshold} (default: 10 MiB)
15795 When @code{cache} is true, this is the maximum size in bytes of a store
15796 item for which @command{guix publish} may bypass its cache in case of a
15797 cache miss. @xref{Invoking guix publish,
15798 @option{--cache-bypass-threshold}}, for more information.
15800 @item @code{ttl} (default: @code{#f})
15801 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15802 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15803 for more information.
15807 @anchor{rngd-service}
15808 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15809 [#:device "/dev/hwrng"]
15810 Return a service that runs the @command{rngd} program from @var{rng-tools}
15811 to add @var{device} to the kernel's entropy pool. The service will fail if
15812 @var{device} does not exist.
15815 @anchor{pam-limits-service}
15816 @cindex session limits
15822 @cindex open file descriptors
15823 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15825 Return a service that installs a configuration file for the
15826 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15827 @code{pam_limits} module}. The procedure optionally takes a list of
15828 @code{pam-limits-entry} values, which can be used to specify
15829 @code{ulimit} limits and @code{nice} priority limits to user sessions.
15831 The following limits definition sets two hard and soft limits for all
15832 login sessions of users in the @code{realtime} group:
15835 (pam-limits-service
15837 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15838 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15841 The first entry increases the maximum realtime priority for
15842 non-privileged processes; the second entry lifts any restriction of the
15843 maximum address space that can be locked in memory. These settings are
15844 commonly used for real-time audio systems.
15846 Another useful example is raising the maximum number of open file
15847 descriptors that can be used:
15850 (pam-limits-service
15852 (pam-limits-entry "*" 'both 'nofile 100000)))
15855 In the above example, the asterisk means the limit should apply to any
15856 user. It is important to ensure the chosen value doesn't exceed the
15857 maximum system value visible in the @file{/proc/sys/fs/file-max} file,
15858 else the users would be prevented from login in. For more information
15859 about the Pluggable Authentication Module (PAM) limits, refer to the
15860 @samp{pam_limits} man page from the @code{linux-pam} package.
15863 @node Scheduled Job Execution
15864 @subsection Scheduled Job Execution
15868 @cindex scheduling jobs
15869 The @code{(gnu services mcron)} module provides an interface to
15870 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15871 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15872 Unix @command{cron} daemon; the main difference is that it is
15873 implemented in Guile Scheme, which provides a lot of flexibility when
15874 specifying the scheduling of jobs and their actions.
15876 The example below defines an operating system that runs the
15877 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15878 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15879 well as the @command{mkid} command on behalf of an unprivileged user
15880 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15881 gexps to introduce job definitions that are passed to mcron
15882 (@pxref{G-Expressions}).
15885 (use-modules (guix) (gnu) (gnu services mcron))
15886 (use-package-modules base idutils)
15888 (define updatedb-job
15889 ;; Run 'updatedb' at 3AM every day. Here we write the
15890 ;; job's action as a Scheme procedure.
15891 #~(job '(next-hour '(3))
15893 (execl (string-append #$findutils "/bin/updatedb")
15895 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15897 (define garbage-collector-job
15898 ;; Collect garbage 5 minutes after midnight every day.
15899 ;; The job's action is a shell command.
15900 #~(job "5 0 * * *" ;Vixie cron syntax
15903 (define idutils-job
15904 ;; Update the index database as user "charlie" at 12:15PM
15905 ;; and 19:15PM. This runs from the user's home directory.
15906 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15907 (string-append #$idutils "/bin/mkid src")
15913 ;; %BASE-SERVICES already includes an instance of
15914 ;; 'mcron-service-type', which we extend with additional
15915 ;; jobs using 'simple-service'.
15916 (services (cons (simple-service 'my-cron-jobs
15918 (list garbage-collector-job
15924 For more complex jobs defined in Scheme where you need control over the top
15925 level, for instance to introduce a @code{use-modules} form, you can move your
15926 code to a separate program using the @code{program-file} procedure of the
15927 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15931 (define %battery-alert-job
15932 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15934 '(next-minute (range 0 60 1))
15936 "battery-alert.scm"
15937 (with-imported-modules (source-module-closure
15938 '((guix build utils)))
15940 (use-modules (guix build utils)
15943 (ice-9 textual-ports)
15946 (define %min-level 20)
15948 (setenv "LC_ALL" "C") ;ensure English output
15949 (and-let* ((input-pipe (open-pipe*
15951 #$(file-append acpi "/bin/acpi")))
15952 (output (get-string-all input-pipe))
15953 (m (string-match "Discharging, ([0-9]+)%" output))
15954 (level (string->number (match:substring m 1)))
15955 ((< level %min-level)))
15956 (format #t "warning: Battery level is low (~a%)~%" level)
15957 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15960 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15961 for more information on mcron job specifications. Below is the
15962 reference of the mcron service.
15964 On a running system, you can use the @code{schedule} action of the service to
15965 visualize the mcron jobs that will be executed next:
15968 # herd schedule mcron
15972 The example above lists the next five tasks that will be executed, but you can
15973 also specify the number of tasks to display:
15976 # herd schedule mcron 10
15979 @defvr {Scheme Variable} mcron-service-type
15980 This is the type of the @code{mcron} service, whose value is an
15981 @code{mcron-configuration} object.
15983 This service type can be the target of a service extension that provides
15984 it additional job specifications (@pxref{Service Composition}). In
15985 other words, it is possible to define services that provide additional
15989 @deftp {Data Type} mcron-configuration
15990 Data type representing the configuration of mcron.
15993 @item @code{mcron} (default: @var{mcron})
15994 The mcron package to use.
15997 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15998 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15999 specifications,, mcron, GNU@tie{}mcron}).
16005 @subsection Log Rotation
16008 @cindex log rotation
16010 Log files such as those found in @file{/var/log} tend to grow endlessly,
16011 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
16012 their contents in separate files, possibly compressed. The @code{(gnu
16013 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
16014 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
16016 This service is part of @code{%base-services}, and thus enabled by
16017 default, with the default settings, for commonly encountered log files.
16018 The example below shows how to extend it with an additional
16019 @dfn{rotation}, should you need to do that (usually, services that
16020 produce log files already take care of that):
16023 (use-modules (guix) (gnu))
16024 (use-service-modules admin)
16026 (define my-log-files
16027 ;; Log files that I want to rotate.
16028 '("/var/log/something.log" "/var/log/another.log"))
16032 (services (cons (simple-service 'rotate-my-stuff
16033 rottlog-service-type
16034 (list (log-rotation
16036 (files my-log-files))))
16040 @defvr {Scheme Variable} rottlog-service-type
16041 This is the type of the Rottlog service, whose value is a
16042 @code{rottlog-configuration} object.
16044 Other services can extend this one with new @code{log-rotation} objects
16045 (see below), thereby augmenting the set of files to be rotated.
16047 This service type can define mcron jobs (@pxref{Scheduled Job
16048 Execution}) to run the rottlog service.
16051 @deftp {Data Type} rottlog-configuration
16052 Data type representing the configuration of rottlog.
16055 @item @code{rottlog} (default: @code{rottlog})
16056 The Rottlog package to use.
16058 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
16059 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
16060 rottlog, GNU Rot[t]log Manual}).
16062 @item @code{rotations} (default: @code{%default-rotations})
16063 A list of @code{log-rotation} objects as defined below.
16066 This is a list of gexps where each gexp corresponds to an mcron job
16067 specification (@pxref{Scheduled Job Execution}).
16071 @deftp {Data Type} log-rotation
16072 Data type representing the rotation of a group of log files.
16074 Taking an example from the Rottlog manual (@pxref{Period Related File
16075 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
16081 (files '("/var/log/apache/*"))
16082 (options '("storedir apache-archives"
16088 The list of fields is as follows:
16091 @item @code{frequency} (default: @code{'weekly})
16092 The log rotation frequency, a symbol.
16095 The list of files or file glob patterns to rotate.
16097 @item @code{options} (default: @code{'()})
16098 The list of rottlog options for this rotation (@pxref{Configuration
16099 parameters,,, rottlog, GNU Rot[t]lg Manual}).
16101 @item @code{post-rotate} (default: @code{#f})
16102 Either @code{#f} or a gexp to execute once the rotation has completed.
16106 @defvr {Scheme Variable} %default-rotations
16107 Specifies weekly rotation of @code{%rotated-files} and of
16108 @file{/var/log/guix-daemon.log}.
16111 @defvr {Scheme Variable} %rotated-files
16112 The list of syslog-controlled files to be rotated. By default it is:
16113 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
16114 "/var/log/maillog")}.
16117 @node Networking Services
16118 @subsection Networking Services
16120 The @code{(gnu services networking)} module provides services to configure
16121 the network interface.
16123 @cindex DHCP, networking service
16124 @defvr {Scheme Variable} dhcp-client-service-type
16125 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
16126 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
16127 is the DHCP client package to use, @code{isc-dhcp} by default.
16130 @deffn {Scheme Procedure} dhcpd-service-type
16131 This type defines a service that runs a DHCP daemon. To create a
16132 service of this type, you must supply a @code{<dhcpd-configuration>}.
16136 (service dhcpd-service-type
16137 (dhcpd-configuration
16138 (config-file (local-file "my-dhcpd.conf"))
16139 (interfaces '("enp0s25"))))
16143 @deftp {Data Type} dhcpd-configuration
16145 @item @code{package} (default: @code{isc-dhcp})
16146 The package that provides the DHCP daemon. This package is expected to
16147 provide the daemon at @file{sbin/dhcpd} relative to its output
16148 directory. The default package is the
16149 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
16150 @item @code{config-file} (default: @code{#f})
16151 The configuration file to use. This is required. It will be passed to
16152 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
16153 object (@pxref{G-Expressions, file-like objects}). See @code{man
16154 dhcpd.conf} for details on the configuration file syntax.
16155 @item @code{version} (default: @code{"4"})
16156 The DHCP version to use. The ISC DHCP server supports the values ``4'',
16157 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
16158 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
16160 @item @code{run-directory} (default: @code{"/run/dhcpd"})
16161 The run directory to use. At service activation time, this directory
16162 will be created if it does not exist.
16163 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
16164 The PID file to use. This corresponds to the @code{-pf} option of
16165 @code{dhcpd}. See @code{man dhcpd} for details.
16166 @item @code{interfaces} (default: @code{'()})
16167 The names of the network interfaces on which dhcpd should listen for
16168 broadcasts. If this list is not empty, then its elements (which must be
16169 strings) will be appended to the @code{dhcpd} invocation when starting
16170 the daemon. It may not be necessary to explicitly specify any
16171 interfaces here; see @code{man dhcpd} for details.
16175 @defvr {Scheme Variable} static-networking-service-type
16176 This is the type for statically-configured network interfaces.
16177 @c TODO Document <static-networking> data structures.
16180 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
16181 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
16182 [#:requirement @code{'(udev)}]
16183 Return a service that starts @var{interface} with address @var{ip}. If
16184 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
16185 it must be a string specifying the default network gateway. @var{requirement}
16186 can be used to declare a dependency on another service before configuring the
16189 This procedure can be called several times, one for each network
16190 interface of interest. Behind the scenes what it does is extend
16191 @code{static-networking-service-type} with additional network interfaces
16197 (static-networking-service "eno1" "192.168.1.82"
16198 #:gateway "192.168.1.2"
16199 #:name-servers '("192.168.1.2"))
16206 @cindex network management
16207 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
16208 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
16209 management daemon that aims to simplify wired and wireless networking.
16211 This service adds the @var{wicd} package to the global profile, providing
16212 several commands to interact with the daemon and configure networking:
16213 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
16214 and @command{wicd-curses} user interfaces.
16217 @cindex ModemManager
16219 @defvr {Scheme Variable} modem-manager-service-type
16220 This is the service type for the
16221 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
16222 service. The value for this service type is a
16223 @code{modem-manager-configuration} record.
16225 This service is part of @code{%desktop-services} (@pxref{Desktop
16229 @deftp {Data Type} modem-manager-configuration
16230 Data type representing the configuration of ModemManager.
16233 @item @code{modem-manager} (default: @code{modem-manager})
16234 The ModemManager package to use.
16239 @cindex USB_ModeSwitch
16240 @cindex Modeswitching
16242 @defvr {Scheme Variable} usb-modeswitch-service-type
16243 This is the service type for the
16244 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
16245 service. The value for this service type is
16246 a @code{usb-modeswitch-configuration} record.
16248 When plugged in, some USB modems (and other USB devices) initially present
16249 themselves as a read-only storage medium and not as a modem. They need to be
16250 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
16251 installs udev rules to automatically modeswitch these devices when they are
16254 This service is part of @code{%desktop-services} (@pxref{Desktop
16258 @deftp {Data Type} usb-modeswitch-configuration
16259 Data type representing the configuration of USB_ModeSwitch.
16262 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
16263 The USB_ModeSwitch package providing the binaries for modeswitching.
16265 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
16266 The package providing the device data and udev rules file used by
16269 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
16270 Which config file to use for the USB_ModeSwitch dispatcher. By default the
16271 config file shipped with USB_ModeSwitch is used which disables logging to
16272 @file{/var/log} among other default settings. If set to @code{#f}, no config
16278 @cindex NetworkManager
16280 @defvr {Scheme Variable} network-manager-service-type
16281 This is the service type for the
16282 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
16283 service. The value for this service type is a
16284 @code{network-manager-configuration} record.
16286 This service is part of @code{%desktop-services} (@pxref{Desktop
16290 @deftp {Data Type} network-manager-configuration
16291 Data type representing the configuration of NetworkManager.
16294 @item @code{network-manager} (default: @code{network-manager})
16295 The NetworkManager package to use.
16297 @item @code{dns} (default: @code{"default"})
16298 Processing mode for DNS, which affects how NetworkManager uses the
16299 @code{resolv.conf} configuration file.
16303 NetworkManager will update @code{resolv.conf} to reflect the nameservers
16304 provided by currently active connections.
16307 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
16308 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
16309 then update @code{resolv.conf} to point to the local nameserver.
16311 With this setting, you can share your network connection. For example when
16312 you want to share your network connection to another laptop @i{via} an
16313 Ethernet cable, you can open @command{nm-connection-editor} and configure the
16314 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
16315 and reestablish the connection (or reboot).
16317 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
16318 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
16319 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
16320 browser on your host system, or connect to the VM @i{via} SSH
16321 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
16322 host-to-guest connection, run this command once:
16325 nmcli connection add type tun \
16326 connection.interface-name tap0 \
16327 tun.mode tap tun.owner $(id -u) \
16328 ipv4.method shared \
16329 ipv4.addresses 172.28.112.1/24
16332 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
16333 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
16334 @command{qemu-system-...}.
16337 NetworkManager will not modify @code{resolv.conf}.
16340 @item @code{vpn-plugins} (default: @code{'()})
16341 This is the list of available plugins for virtual private networks
16342 (VPNs). An example of this is the @code{network-manager-openvpn}
16343 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
16349 @deffn {Scheme Variable} connman-service-type
16350 This is the service type to run @url{https://01.org/connman,Connman},
16351 a network connection manager.
16353 Its value must be an
16354 @code{connman-configuration} record as in this example:
16357 (service connman-service-type
16358 (connman-configuration
16359 (disable-vpn? #t)))
16362 See below for details about @code{connman-configuration}.
16365 @deftp {Data Type} connman-configuration
16366 Data Type representing the configuration of connman.
16369 @item @code{connman} (default: @var{connman})
16370 The connman package to use.
16372 @item @code{disable-vpn?} (default: @code{#f})
16373 When true, disable connman's vpn plugin.
16377 @cindex WPA Supplicant
16378 @defvr {Scheme Variable} wpa-supplicant-service-type
16379 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
16380 supplicant}, an authentication daemon required to authenticate against
16381 encrypted WiFi or ethernet networks.
16384 @deftp {Data Type} wpa-supplicant-configuration
16385 Data type representing the configuration of WPA Supplicant.
16387 It takes the following parameters:
16390 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
16391 The WPA Supplicant package to use.
16393 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
16394 List of services that should be started before WPA Supplicant starts.
16396 @item @code{dbus?} (default: @code{#t})
16397 Whether to listen for requests on D-Bus.
16399 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
16400 Where to store the PID file.
16402 @item @code{interface} (default: @code{#f})
16403 If this is set, it must specify the name of a network interface that
16404 WPA supplicant will control.
16406 @item @code{config-file} (default: @code{#f})
16407 Optional configuration file to use.
16409 @item @code{extra-options} (default: @code{'()})
16410 List of additional command-line arguments to pass to the daemon.
16414 @cindex hostapd service, for Wi-Fi access points
16415 @cindex Wi-Fi access points, hostapd service
16416 @defvr {Scheme Variable} hostapd-service-type
16417 This is the service type to run the @uref{https://w1.fi/hostapd/,
16418 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
16419 authentication servers. Its associated value must be a
16420 @code{hostapd-configuration} as shown below:
16423 ;; Use wlan1 to run the access point for "My Network".
16424 (service hostapd-service-type
16425 (hostapd-configuration
16426 (interface "wlan1")
16427 (ssid "My Network")
16432 @deftp {Data Type} hostapd-configuration
16433 This data type represents the configuration of the hostapd service, with
16434 the following fields:
16437 @item @code{package} (default: @code{hostapd})
16438 The hostapd package to use.
16440 @item @code{interface} (default: @code{"wlan0"})
16441 The network interface to run the WiFi access point.
16444 The SSID (@dfn{service set identifier}), a string that identifies this
16447 @item @code{broadcast-ssid?} (default: @code{#t})
16448 Whether to broadcast this SSID.
16450 @item @code{channel} (default: @code{1})
16451 The WiFi channel to use.
16453 @item @code{driver} (default: @code{"nl80211"})
16454 The driver interface type. @code{"nl80211"} is used with all Linux
16455 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16456 RADIUS server that does # not control any wireless/wired driver.
16458 @item @code{extra-settings} (default: @code{""})
16459 Extra settings to append as-is to the hostapd configuration file. See
16460 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16461 configuration file reference.
16465 @defvr {Scheme Variable} simulated-wifi-service-type
16466 This is the type of a service to simulate WiFi networking, which can be
16467 useful in virtual machines for testing purposes. The service loads the
16469 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16470 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16471 network that can be seen on @code{wlan0}, by default.
16473 The service's value is a @code{hostapd-configuration} record.
16477 @defvr {Scheme Variable} iptables-service-type
16478 This is the service type to set up an iptables configuration. iptables is a
16479 packet filtering framework supported by the Linux kernel. This service
16480 supports configuring iptables for both IPv4 and IPv6. A simple example
16481 configuration rejecting all incoming connections except those to the ssh port
16485 (service iptables-service-type
16486 (iptables-configuration
16487 (ipv4-rules (plain-file "iptables.rules" "*filter
16491 -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
16492 -A INPUT -p tcp --dport 22 -j ACCEPT
16493 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16496 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16500 -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
16501 -A INPUT -p tcp --dport 22 -j ACCEPT
16502 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16508 @deftp {Data Type} iptables-configuration
16509 The data type representing the configuration of iptables.
16512 @item @code{iptables} (default: @code{iptables})
16513 The iptables package that provides @code{iptables-restore} and
16514 @code{ip6tables-restore}.
16515 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16516 The iptables rules to use. It will be passed to @code{iptables-restore}.
16517 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16519 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16520 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16521 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16527 @defvr {Scheme Variable} nftables-service-type
16528 This is the service type to set up a nftables configuration. nftables is a
16529 netfilter project that aims to replace the existing iptables, ip6tables,
16530 arptables and ebtables framework. It provides a new packet filtering
16531 framework, a new user-space utility @command{nft}, and a compatibility layer
16532 for iptables. This service comes with a default ruleset
16533 @code{%default-nftables-ruleset} that rejecting all incoming connections
16534 except those to the ssh port 22. To use it, simply write:
16537 (service nftables-service-type)
16541 @deftp {Data Type} nftables-configuration
16542 The data type representing the configuration of nftables.
16545 @item @code{package} (default: @code{nftables})
16546 The nftables package that provides @command{nft}.
16547 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16548 The nftables ruleset to use. This may be any ``file-like'' object
16549 (@pxref{G-Expressions, file-like objects}).
16553 @cindex NTP (Network Time Protocol), service
16554 @cindex ntpd, service for the Network Time Protocol daemon
16555 @cindex real time clock
16556 @defvr {Scheme Variable} ntp-service-type
16557 This is the type of the service running the @uref{https://www.ntp.org,
16558 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16559 system clock synchronized with that of the specified NTP servers.
16561 The value of this service is an @code{ntpd-configuration} object, as described
16565 @deftp {Data Type} ntp-configuration
16566 This is the data type for the NTP service configuration.
16569 @item @code{servers} (default: @code{%ntp-servers})
16570 This is the list of servers (@code{<ntp-server>} records) with which
16571 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16574 @item @code{allow-large-adjustment?} (default: @code{#t})
16575 This determines whether @command{ntpd} is allowed to make an initial
16576 adjustment of more than 1,000 seconds.
16578 @item @code{ntp} (default: @code{ntp})
16579 The NTP package to use.
16583 @defvr {Scheme Variable} %ntp-servers
16584 List of host names used as the default NTP servers. These are servers of the
16585 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16588 @deftp {Data Type} ntp-server
16589 The data type representing the configuration of a NTP server.
16592 @item @code{type} (default: @code{'server})
16593 The type of the NTP server, given as a symbol. One of @code{'pool},
16594 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16596 @item @code{address}
16597 The address of the server, as a string.
16599 @item @code{options}
16600 NTPD options to use with that specific server, given as a list of option names
16601 and/or of option names and values tuples. The following example define a server
16602 to use with the options @option{iburst} and @option{prefer}, as well as
16603 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16608 (address "some.ntp.server.org")
16609 (options `(iburst (version 3) (maxpoll 16) prefer))))
16615 @deffn {Scheme Procedure} openntpd-service-type
16616 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16617 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16618 clock synchronized with that of the given servers.
16622 openntpd-service-type
16623 (openntpd-configuration
16624 (listen-on '("127.0.0.1" "::1"))
16625 (sensor '("udcf0 correction 70000"))
16626 (constraint-from '("www.gnu.org"))
16627 (constraints-from '("https://www.google.com/"))))
16632 @defvr {Scheme Variable} %openntpd-servers
16633 This variable is a list of the server addresses defined in
16634 @code{%ntp-servers}.
16637 @deftp {Data Type} openntpd-configuration
16639 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16640 The openntpd executable to use.
16641 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16642 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16643 @item @code{query-from} (default: @code{'()})
16644 A list of local IP address the ntpd daemon should use for outgoing queries.
16645 @item @code{sensor} (default: @code{'()})
16646 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16647 will listen to each sensor that actually exists and ignore non-existent ones.
16648 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16650 @item @code{server} (default: @code{'()})
16651 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16652 @item @code{servers} (default: @code{%openntp-servers})
16653 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16654 @item @code{constraint-from} (default: @code{'()})
16655 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16656 This time information is not used for precision but acts as an authenticated
16657 constraint, thereby reducing the impact of unauthenticated NTP
16658 man-in-the-middle attacks.
16659 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16661 @item @code{constraints-from} (default: @code{'()})
16662 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16663 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16664 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16669 @deffn {Scheme variable} inetd-service-type
16670 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16671 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16672 connections on internet sockets, and lazily starts the specified server
16673 program when a connection is made on one of these sockets.
16675 The value of this service is an @code{inetd-configuration} object. The
16676 following example configures the @command{inetd} daemon to provide the
16677 built-in @command{echo} service, as well as an smtp service which
16678 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16679 gateway @code{hostname}:
16684 (inetd-configuration
16688 (socket-type 'stream)
16695 (socket-type 'stream)
16699 (program (file-append openssh "/bin/ssh"))
16701 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16702 "-W" "smtp-server:25" "user@@hostname")))))))
16705 See below for more details about @code{inetd-configuration}.
16708 @deftp {Data Type} inetd-configuration
16709 Data type representing the configuration of @command{inetd}.
16712 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16713 The @command{inetd} executable to use.
16715 @item @code{entries} (default: @code{'()})
16716 A list of @command{inetd} service entries. Each entry should be created
16717 by the @code{inetd-entry} constructor.
16721 @deftp {Data Type} inetd-entry
16722 Data type representing an entry in the @command{inetd} configuration.
16723 Each entry corresponds to a socket where @command{inetd} will listen for
16727 @item @code{node} (default: @code{#f})
16728 Optional string, a comma-separated list of local addresses
16729 @command{inetd} should use when listening for this service.
16730 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16731 description of all options.
16733 A string, the name must correspond to an entry in @code{/etc/services}.
16734 @item @code{socket-type}
16735 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16737 @item @code{protocol}
16738 A string, must correspond to an entry in @code{/etc/protocols}.
16739 @item @code{wait?} (default: @code{#t})
16740 Whether @command{inetd} should wait for the server to exit before
16741 listening to new service requests.
16743 A string containing the user (and, optionally, group) name of the user
16744 as whom the server should run. The group name can be specified in a
16745 suffix, separated by a colon or period, i.e.@: @code{"user"},
16746 @code{"user:group"} or @code{"user.group"}.
16747 @item @code{program} (default: @code{"internal"})
16748 The server program which will serve the requests, or @code{"internal"}
16749 if @command{inetd} should use a built-in service.
16750 @item @code{arguments} (default: @code{'()})
16751 A list strings or file-like objects, which are the server program's
16752 arguments, starting with the zeroth argument, i.e.@: the name of the
16753 program itself. For @command{inetd}'s internal services, this entry
16754 must be @code{'()} or @code{'("internal")}.
16757 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16758 detailed discussion of each configuration field.
16761 @cindex opendht, distributed hash table network service
16762 @cindex dhtproxy, for use with jami
16763 @defvr {Scheme Variable} opendht-service-type
16764 This is the type of the service running a @uref{https://opendht.net,
16765 OpenDHT} node, @command{dhtnode}. The daemon can be used to host your
16766 own proxy service to the distributed hash table (DHT), for example to
16767 connect to with Jami, among other applications.
16769 @quotation Important
16770 When using the OpenDHT proxy server, the IP addresses it ``sees'' from
16771 the clients should be addresses reachable from other peers. In practice
16772 this means that a publicly reachable address is best suited for a proxy
16773 server, outside of your private network. For example, hosting the proxy
16774 server on a IPv4 private local network and exposing it via port
16775 forwarding could work for external peers, but peers local to the proxy
16776 would have their private addresses shared with the external peers,
16777 leading to connectivity problems.
16780 The value of this service is a @code{opendht-configuration} object, as
16784 @deftp {Data Type} opendht-configuration
16785 This is the data type for the OpenDHT service configuration.
16787 @c The fields documentation has been auto-generated using the
16788 @c configuration->documentation procedure from
16789 @c (gnu services configuration).
16790 Available @code{opendht-configuration} fields are:
16792 @deftypevr {@code{opendht-configuration} parameter} package opendht
16793 The @code{opendht} package to use.
16797 @deftypevr {@code{opendht-configuration} parameter} boolean peer-discovery?
16798 Whether to enable the multicast local peer discovery mechanism.
16800 Defaults to @samp{#f}.
16804 @deftypevr {@code{opendht-configuration} parameter} boolean enable-logging?
16805 Whether to enable logging messages to syslog. It is disabled by default
16806 as it is rather verbose.
16808 Defaults to @samp{#f}.
16812 @deftypevr {@code{opendht-configuration} parameter} boolean debug?
16813 Whether to enable debug-level logging messages. This has no effect if
16814 logging is disabled.
16816 Defaults to @samp{#f}.
16820 @deftypevr {@code{opendht-configuration} parameter} maybe-string bootstrap-host
16821 The node host name that is used to make the first connection to the
16822 network. A specific port value can be provided by appending the
16823 @code{:PORT} suffix. By default, it uses the Jami bootstrap nodes, but
16824 any host can be specified here. It's also possible to disable
16825 bootsrapping by setting this to the @code{'disabled} symbol.
16827 Defaults to @samp{"bootstrap.jami.net:4222"}.
16831 @deftypevr {@code{opendht-configuration} parameter} maybe-number port
16832 The UDP port to bind to. When set to @code{'disabled}, an available
16833 port is automatically selected.
16835 Defaults to @samp{4222}.
16839 @deftypevr {@code{opendht-configuration} parameter} maybe-number proxy-server-port
16840 Spawn a proxy server listening on the specified port.
16842 Defaults to @samp{disabled}.
16846 @deftypevr {@code{opendht-configuration} parameter} maybe-number proxy-server-port-tls
16847 Spawn a proxy server listening to TLS connections on the specified port.
16849 Defaults to @samp{disabled}.
16855 @defvr {Scheme Variable} tor-service-type
16856 This is the type for a service that runs the @uref{https://torproject.org,
16857 Tor} anonymous networking daemon. The service is configured using a
16858 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16859 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16863 @deftp {Data Type} tor-configuration
16865 @item @code{tor} (default: @code{tor})
16866 The package that provides the Tor daemon. This package is expected to provide
16867 the daemon at @file{bin/tor} relative to its output directory. The default
16868 package is the @uref{https://www.torproject.org, Tor Project's}
16871 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16872 The configuration file to use. It will be appended to a default configuration
16873 file, and the final configuration file will be passed to @code{tor} via its
16874 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16875 file-like objects}). See @code{man tor} for details on the configuration file
16878 @item @code{hidden-services} (default: @code{'()})
16879 The list of @code{<hidden-service>} records to use. For any hidden service
16880 you include in this list, appropriate configuration to enable the hidden
16881 service will be automatically added to the default configuration file. You
16882 may conveniently create @code{<hidden-service>} records using the
16883 @code{tor-hidden-service} procedure described below.
16885 @item @code{socks-socket-type} (default: @code{'tcp})
16886 The default socket type that Tor should use for its SOCKS socket. This must
16887 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16888 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16889 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16890 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16893 If you want to customize the SOCKS socket in more detail, leave
16894 @code{socks-socket-type} at its default value of @code{'tcp} and use
16895 @code{config-file} to override the default by providing your own
16896 @code{SocksPort} option.
16898 @item @code{control-socket?} (default: @code{#f})
16899 Whether or not to provide a ``control socket'' by which Tor can be
16900 controlled to, for instance, dynamically instantiate tor onion services.
16901 If @code{#t}, Tor will listen for control commands on the UNIX domain socket
16902 @file{/var/run/tor/control-sock}, which will be made writable by members of the
16908 @cindex hidden service
16909 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16910 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16911 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16914 '((22 "127.0.0.1:22")
16915 (80 "127.0.0.1:8080"))
16918 In this example, port 22 of the hidden service is mapped to local port 22, and
16919 port 80 is mapped to local port 8080.
16921 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16922 the @file{hostname} file contains the @code{.onion} host name for the hidden
16925 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16926 project's documentation} for more information.
16929 The @code{(gnu services rsync)} module provides the following services:
16931 You might want an rsync daemon if you have files that you want available
16932 so anyone (or just yourself) can download existing files or upload new
16935 @deffn {Scheme Variable} rsync-service-type
16936 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16937 The value for this service type is a
16938 @command{rsync-configuration} record as in this example:
16941 (service rsync-service-type)
16944 See below for details about @code{rsync-configuration}.
16947 @deftp {Data Type} rsync-configuration
16948 Data type representing the configuration for @code{rsync-service}.
16951 @item @code{package} (default: @var{rsync})
16952 @code{rsync} package to use.
16954 @item @code{port-number} (default: @code{873})
16955 TCP port on which @command{rsync} listens for incoming connections. If port
16956 is less than @code{1024} @command{rsync} needs to be started as the
16957 @code{root} user and group.
16959 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16960 Name of the file where @command{rsync} writes its PID.
16962 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16963 Name of the file where @command{rsync} writes its lock file.
16965 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16966 Name of the file where @command{rsync} writes its log file.
16968 @item @code{use-chroot?} (default: @var{#t})
16969 Whether to use chroot for @command{rsync} shared directory.
16971 @item @code{share-path} (default: @file{/srv/rsync})
16972 Location of the @command{rsync} shared directory.
16974 @item @code{share-comment} (default: @code{"Rsync share"})
16975 Comment of the @command{rsync} shared directory.
16977 @item @code{read-only?} (default: @var{#f})
16978 Read-write permissions to shared directory.
16980 @item @code{timeout} (default: @code{300})
16981 I/O timeout in seconds.
16983 @item @code{user} (default: @var{"root"})
16984 Owner of the @code{rsync} process.
16986 @item @code{group} (default: @var{"root"})
16987 Group of the @code{rsync} process.
16989 @item @code{uid} (default: @var{"rsyncd"})
16990 User name or user ID that file transfers to and from that module should take
16991 place as when the daemon was run as @code{root}.
16993 @item @code{gid} (default: @var{"rsyncd"})
16994 Group name or group ID that will be used when accessing the module.
16999 The @code{(gnu services syncthing)} module provides the following services:
17002 You might want a syncthing daemon if you have files between two or more
17003 computers and want to sync them in real time, safely protected from
17006 @deffn {Scheme Variable} syncthing-service-type
17007 This is the service type for the @uref{https://syncthing.net/,
17008 syncthing} daemon, The value for this service type is a
17009 @command{syncthing-configuration} record as in this example:
17012 (service syncthing-service-type
17013 (syncthing-configuration (user "alice")))
17016 See below for details about @code{syncthing-configuration}.
17018 @deftp {Data Type} syncthing-configuration
17019 Data type representing the configuration for @code{syncthing-service-type}.
17022 @item @code{syncthing} (default: @var{syncthing})
17023 @code{syncthing} package to use.
17025 @item @code{arguments} (default: @var{'()})
17026 List of command-line arguments passing to @code{syncthing} binary.
17028 @item @code{logflags} (default: @var{0})
17029 Sum of logging flags, see
17030 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
17032 @item @code{user} (default: @var{#f})
17033 The user as which the Syncthing service is to be run.
17034 This assumes that the specified user exists.
17036 @item @code{group} (default: @var{"users"})
17037 The group as which the Syncthing service is to be run.
17038 This assumes that the specified group exists.
17040 @item @code{home} (default: @var{#f})
17041 Common configuration and data directory. The default configuration
17042 directory is @file{$HOME} of the specified Syncthing @code{user}.
17048 Furthermore, @code{(gnu services ssh)} provides the following services.
17052 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
17053 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
17054 [#:allow-empty-passwords? #f] [#:root-login? #f] @
17055 [#:syslog-output? #t] [#:x11-forwarding? #t] @
17056 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
17057 [#:public-key-authentication? #t] [#:initialize? #t]
17058 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
17059 @var{host-key} must designate a file containing the host key, and readable
17062 When @var{daemonic?} is true, @command{lshd} will detach from the
17063 controlling terminal and log its output to syslogd, unless one sets
17064 @var{syslog-output?} to false. Obviously, it also makes lsh-service
17065 depend on existence of syslogd service. When @var{pid-file?} is true,
17066 @command{lshd} writes its PID to the file called @var{pid-file}.
17068 When @var{initialize?} is true, automatically create the seed and host key
17069 upon service activation if they do not exist yet. This may take long and
17070 require interaction.
17072 When @var{initialize?} is false, it is up to the user to initialize the
17073 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
17074 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
17075 basics,,, lsh, LSH Manual}).
17077 When @var{interfaces} is empty, lshd listens for connections on all the
17078 network interfaces; otherwise, @var{interfaces} must be a list of host names
17081 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
17082 passwords, and @var{root-login?} specifies whether to accept log-ins as
17085 The other options should be self-descriptive.
17090 @deffn {Scheme Variable} openssh-service-type
17091 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
17092 shell daemon, @command{sshd}. Its value must be an
17093 @code{openssh-configuration} record as in this example:
17096 (service openssh-service-type
17097 (openssh-configuration
17098 (x11-forwarding? #t)
17099 (permit-root-login 'prohibit-password)
17101 `(("alice" ,(local-file "alice.pub"))
17102 ("bob" ,(local-file "bob.pub"))))))
17105 See below for details about @code{openssh-configuration}.
17107 This service can be extended with extra authorized keys, as in this
17111 (service-extension openssh-service-type
17112 (const `(("charlie"
17113 ,(local-file "charlie.pub")))))
17117 @deftp {Data Type} openssh-configuration
17118 This is the configuration record for OpenSSH's @command{sshd}.
17121 @item @code{openssh} (default @var{openssh})
17122 The Openssh package to use.
17124 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
17125 Name of the file where @command{sshd} writes its PID.
17127 @item @code{port-number} (default: @code{22})
17128 TCP port on which @command{sshd} listens for incoming connections.
17130 @item @code{permit-root-login} (default: @code{#f})
17131 This field determines whether and when to allow logins as root. If
17132 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
17133 If it's the symbol @code{'prohibit-password}, then root logins are
17134 permitted but not with password-based authentication.
17136 @item @code{allow-empty-passwords?} (default: @code{#f})
17137 When true, users with empty passwords may log in. When false, they may
17140 @item @code{password-authentication?} (default: @code{#t})
17141 When true, users may log in with their password. When false, they have
17142 other authentication methods.
17144 @item @code{public-key-authentication?} (default: @code{#t})
17145 When true, users may log in using public key authentication. When
17146 false, users have to use other authentication method.
17148 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
17149 This is used only by protocol version 2.
17151 @item @code{x11-forwarding?} (default: @code{#f})
17152 When true, forwarding of X11 graphical client connections is
17153 enabled---in other words, @command{ssh} options @option{-X} and
17154 @option{-Y} will work.
17156 @item @code{allow-agent-forwarding?} (default: @code{#t})
17157 Whether to allow agent forwarding.
17159 @item @code{allow-tcp-forwarding?} (default: @code{#t})
17160 Whether to allow TCP forwarding.
17162 @item @code{gateway-ports?} (default: @code{#f})
17163 Whether to allow gateway ports.
17165 @item @code{challenge-response-authentication?} (default: @code{#f})
17166 Specifies whether challenge response authentication is allowed (e.g.@: via
17169 @item @code{use-pam?} (default: @code{#t})
17170 Enables the Pluggable Authentication Module interface. If set to
17171 @code{#t}, this will enable PAM authentication using
17172 @code{challenge-response-authentication?} and
17173 @code{password-authentication?}, in addition to PAM account and session
17174 module processing for all authentication types.
17176 Because PAM challenge response authentication usually serves an
17177 equivalent role to password authentication, you should disable either
17178 @code{challenge-response-authentication?} or
17179 @code{password-authentication?}.
17181 @item @code{print-last-log?} (default: @code{#t})
17182 Specifies whether @command{sshd} should print the date and time of the
17183 last user login when a user logs in interactively.
17185 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
17186 Configures external subsystems (e.g.@: file transfer daemon).
17188 This is a list of two-element lists, each of which containing the
17189 subsystem name and a command (with optional arguments) to execute upon
17192 The command @command{internal-sftp} implements an in-process SFTP
17193 server. Alternatively, one can specify the @command{sftp-server} command:
17195 (service openssh-service-type
17196 (openssh-configuration
17198 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
17201 @item @code{accepted-environment} (default: @code{'()})
17202 List of strings describing which environment variables may be exported.
17204 Each string gets on its own line. See the @code{AcceptEnv} option in
17205 @code{man sshd_config}.
17207 This example allows ssh-clients to export the @env{COLORTERM} variable.
17208 It is set by terminal emulators, which support colors. You can use it in
17209 your shell's resource file to enable colors for the prompt and commands
17210 if this variable is set.
17213 (service openssh-service-type
17214 (openssh-configuration
17215 (accepted-environment '("COLORTERM"))))
17218 @item @code{authorized-keys} (default: @code{'()})
17219 @cindex authorized keys, SSH
17220 @cindex SSH authorized keys
17221 This is the list of authorized keys. Each element of the list is a user
17222 name followed by one or more file-like objects that represent SSH public
17226 (openssh-configuration
17228 `(("rekado" ,(local-file "rekado.pub"))
17229 ("chris" ,(local-file "chris.pub"))
17230 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
17234 registers the specified public keys for user accounts @code{rekado},
17235 @code{chris}, and @code{root}.
17237 Additional authorized keys can be specified @i{via}
17238 @code{service-extension}.
17240 Note that this does @emph{not} interfere with the use of
17241 @file{~/.ssh/authorized_keys}.
17243 @item @code{log-level} (default: @code{'info})
17244 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
17245 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
17246 page for @file{sshd_config} for the full list of level names.
17248 @item @code{extra-content} (default: @code{""})
17249 This field can be used to append arbitrary text to the configuration file. It
17250 is especially useful for elaborate configurations that cannot be expressed
17251 otherwise. This configuration, for example, would generally disable root
17252 logins, but permit them from one specific IP address:
17255 (openssh-configuration
17257 Match Address 192.168.0.1
17258 PermitRootLogin yes"))
17264 @deffn {Scheme Procedure} dropbear-service [@var{config}]
17265 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
17266 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
17269 For example, to specify a Dropbear service listening on port 1234, add
17270 this call to the operating system's @code{services} field:
17273 (dropbear-service (dropbear-configuration
17274 (port-number 1234)))
17278 @deftp {Data Type} dropbear-configuration
17279 This data type represents the configuration of a Dropbear SSH daemon.
17282 @item @code{dropbear} (default: @var{dropbear})
17283 The Dropbear package to use.
17285 @item @code{port-number} (default: 22)
17286 The TCP port where the daemon waits for incoming connections.
17288 @item @code{syslog-output?} (default: @code{#t})
17289 Whether to enable syslog output.
17291 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
17292 File name of the daemon's PID file.
17294 @item @code{root-login?} (default: @code{#f})
17295 Whether to allow @code{root} logins.
17297 @item @code{allow-empty-passwords?} (default: @code{#f})
17298 Whether to allow empty passwords.
17300 @item @code{password-authentication?} (default: @code{#t})
17301 Whether to enable password-based authentication.
17306 @deffn {Scheme Variable} autossh-service-type
17307 This is the type for the @uref{https://www.harding.motd.ca/autossh,
17308 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
17309 restarting it as necessary should it die or stop passing traffic.
17310 AutoSSH can be run manually from the command-line by passing arguments
17311 to the binary @command{autossh} from the package @code{autossh}, but it
17312 can also be run as a Guix service. This latter use case is documented
17315 AutoSSH can be used to forward local traffic to a remote machine using
17316 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
17319 For example, to specify a service running autossh as the user
17320 @code{pino} and forwarding all local connections to port @code{8081} to
17321 @code{remote:8081} using an SSH tunnel, add this call to the operating
17322 system's @code{services} field:
17325 (service autossh-service-type
17326 (autossh-configuration
17328 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
17332 @deftp {Data Type} autossh-configuration
17333 This data type represents the configuration of an AutoSSH service.
17337 @item @code{user} (default @code{"autossh"})
17338 The user as which the AutoSSH service is to be run.
17339 This assumes that the specified user exists.
17341 @item @code{poll} (default @code{600})
17342 Specifies the connection poll time in seconds.
17344 @item @code{first-poll} (default @code{#f})
17345 Specifies how many seconds AutoSSH waits before the first connection
17346 test. After this first test, polling is resumed at the pace defined in
17347 @code{poll}. When set to @code{#f}, the first poll is not treated
17348 specially and will also use the connection poll specified in
17351 @item @code{gate-time} (default @code{30})
17352 Specifies how many seconds an SSH connection must be active before it is
17353 considered successful.
17355 @item @code{log-level} (default @code{1})
17356 The log level, corresponding to the levels used by syslog---so @code{0}
17357 is the most silent while @code{7} is the chattiest.
17359 @item @code{max-start} (default @code{#f})
17360 The maximum number of times SSH may be (re)started before AutoSSH exits.
17361 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
17363 @item @code{message} (default @code{""})
17364 The message to append to the echo message sent when testing connections.
17366 @item @code{port} (default @code{"0"})
17367 The ports used for monitoring the connection. When set to @code{"0"},
17368 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
17369 a positive integer, ports @var{n} and @var{n}+1 are used for
17370 monitoring the connection, such that port @var{n} is the base
17371 monitoring port and @code{n+1} is the echo port. When set to
17372 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
17373 integers, the ports @var{n} and @var{m} are used for monitoring the
17374 connection, such that port @var{n} is the base monitoring port and
17375 @var{m} is the echo port.
17377 @item @code{ssh-options} (default @code{'()})
17378 The list of command-line arguments to pass to @command{ssh} when it is
17379 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
17380 may cause undefined behaviour.
17386 @deffn {Scheme Variable} webssh-service-type
17387 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
17388 program that runs a web SSH client. WebSSH can be run manually from the
17389 command-line by passing arguments to the binary @command{wssh} from the
17390 package @code{webssh}, but it can also be run as a Guix service. This
17391 latter use case is documented here.
17393 For example, to specify a service running WebSSH on loopback interface
17394 on port @code{8888} with reject policy with a list of allowed to
17395 connection hosts, and NGINX as a reverse-proxy to this service listening
17396 for HTTPS connection, add this call to the operating system's
17397 @code{services} field:
17400 (service webssh-service-type
17401 (webssh-configuration (address "127.0.0.1")
17404 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
17405 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
17407 (service nginx-service-type
17408 (nginx-configuration
17411 (nginx-server-configuration
17412 (inherit %webssh-configuration-nginx)
17413 (server-name '("webssh.example.com"))
17414 (listen '("443 ssl"))
17415 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
17416 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
17418 (cons (nginx-location-configuration
17419 (uri "/.well-known")
17420 (body '("root /var/www;")))
17421 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
17425 @deftp {Data Type} webssh-configuration
17426 Data type representing the configuration for @code{webssh-service}.
17429 @item @code{package} (default: @var{webssh})
17430 @code{webssh} package to use.
17432 @item @code{user-name} (default: @var{"webssh"})
17433 User name or user ID that file transfers to and from that module should take
17436 @item @code{group-name} (default: @var{"webssh"})
17437 Group name or group ID that will be used when accessing the module.
17439 @item @code{address} (default: @var{#f})
17440 IP address on which @command{webssh} listens for incoming connections.
17442 @item @code{port} (default: @var{8888})
17443 TCP port on which @command{webssh} listens for incoming connections.
17445 @item @code{policy} (default: @var{#f})
17446 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
17448 @item @code{known-hosts} (default: @var{'()})
17449 List of hosts which allowed for SSH connection from @command{webssh}.
17451 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
17452 Name of the file where @command{webssh} writes its log file.
17454 @item @code{log-level} (default: @var{#f})
17460 @defvr {Scheme Variable} %facebook-host-aliases
17461 This variable contains a string for use in @file{/etc/hosts}
17462 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
17463 line contains a entry that maps a known server name of the Facebook
17464 on-line service---e.g., @code{www.facebook.com}---to the local
17465 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
17467 This variable is typically used in the @code{hosts-file} field of an
17468 @code{operating-system} declaration (@pxref{operating-system Reference,
17469 @file{/etc/hosts}}):
17472 (use-modules (gnu) (guix))
17475 (host-name "mymachine")
17478 ;; Create a /etc/hosts file with aliases for "localhost"
17479 ;; and "mymachine", as well as for Facebook servers.
17480 (plain-file "hosts"
17481 (string-append (local-host-aliases host-name)
17482 %facebook-host-aliases))))
17485 This mechanism can prevent programs running locally, such as Web
17486 browsers, from accessing Facebook.
17489 The @code{(gnu services avahi)} provides the following definition.
17491 @defvr {Scheme Variable} avahi-service-type
17492 This is the service that runs @command{avahi-daemon}, a system-wide
17493 mDNS/DNS-SD responder that allows for service discovery and
17494 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
17495 Its value must be an @code{avahi-configuration} record---see below.
17497 This service extends the name service cache daemon (nscd) so that it can
17498 resolve @code{.local} host names using
17499 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
17500 Service Switch}, for information on host name resolution.
17502 Additionally, add the @var{avahi} package to the system profile so that
17503 commands such as @command{avahi-browse} are directly usable.
17506 @deftp {Data Type} avahi-configuration
17507 Data type representation the configuration for Avahi.
17511 @item @code{host-name} (default: @code{#f})
17512 If different from @code{#f}, use that as the host name to
17513 publish for this machine; otherwise, use the machine's actual host name.
17515 @item @code{publish?} (default: @code{#t})
17516 When true, allow host names and services to be published (broadcast) over the
17519 @item @code{publish-workstation?} (default: @code{#t})
17520 When true, @command{avahi-daemon} publishes the machine's host name and IP
17521 address via mDNS on the local network. To view the host names published on
17522 your local network, you can run:
17525 avahi-browse _workstation._tcp
17528 @item @code{wide-area?} (default: @code{#f})
17529 When true, DNS-SD over unicast DNS is enabled.
17531 @item @code{ipv4?} (default: @code{#t})
17532 @itemx @code{ipv6?} (default: @code{#t})
17533 These fields determine whether to use IPv4/IPv6 sockets.
17535 @item @code{domains-to-browse} (default: @code{'()})
17536 This is a list of domains to browse.
17540 @deffn {Scheme Variable} openvswitch-service-type
17541 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
17542 service, whose value should be an @code{openvswitch-configuration}
17546 @deftp {Data Type} openvswitch-configuration
17547 Data type representing the configuration of Open vSwitch, a multilayer
17548 virtual switch which is designed to enable massive network automation
17549 through programmatic extension.
17552 @item @code{package} (default: @var{openvswitch})
17553 Package object of the Open vSwitch.
17558 @defvr {Scheme Variable} pagekite-service-type
17559 This is the service type for the @uref{https://pagekite.net, PageKite} service,
17560 a tunneling solution for making localhost servers publicly visible, even from
17561 behind restrictive firewalls or NAT without forwarded ports. The value for
17562 this service type is a @code{pagekite-configuration} record.
17564 Here's an example exposing the local HTTP and SSH daemons:
17567 (service pagekite-service-type
17568 (pagekite-configuration
17569 (kites '("http:@@kitename:localhost:80:@@kitesecret"
17570 "raw/22:@@kitename:localhost:22:@@kitesecret"))
17571 (extra-file "/etc/pagekite.rc")))
17575 @deftp {Data Type} pagekite-configuration
17576 Data type representing the configuration of PageKite.
17579 @item @code{package} (default: @var{pagekite})
17580 Package object of PageKite.
17582 @item @code{kitename} (default: @code{#f})
17583 PageKite name for authenticating to the frontend server.
17585 @item @code{kitesecret} (default: @code{#f})
17586 Shared secret for authenticating to the frontend server. You should probably
17587 put this inside @code{extra-file} instead.
17589 @item @code{frontend} (default: @code{#f})
17590 Connect to the named PageKite frontend server instead of the
17591 @uref{https://pagekite.net,,pagekite.net} service.
17593 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17594 List of service kites to use. Exposes HTTP on port 80 by default. The format
17595 is @code{proto:kitename:host:port:secret}.
17597 @item @code{extra-file} (default: @code{#f})
17598 Extra configuration file to read, which you are expected to create manually.
17599 Use this to add additional options and manage shared secrets out-of-band.
17604 @defvr {Scheme Variable} yggdrasil-service-type
17605 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17606 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17607 encrypted IPv6 network.
17610 Yggdrasil provides name-independent routing with cryptographically generated
17611 addresses. Static addressing means you can keep the same address as long as
17612 you want, even if you move to a new location, or generate a new address (by
17613 generating new keys) whenever you want.
17614 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17617 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17618 peers and/or local peers.
17620 Here is an example using public peers and a static address. The static
17621 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17622 (the default value for @code{config-file}).
17625 ;; part of the operating-system declaration
17626 (service yggdrasil-service-type
17627 (yggdrasil-configuration
17628 (autoconf? #f) ;; use only the public peers
17631 ;; https://github.com/yggdrasil-network/public-peers
17632 '((peers . #("tcp://1.2.3.4:1337"))))
17633 ;; /etc/yggdrasil-private.conf is the default value for config-file
17637 # sample content for /etc/yggdrasil-private.conf
17639 # Your public encryption key. Your peers may ask you for this to put
17640 # into their AllowedEncryptionPublicKeys configuration.
17641 EncryptionPublicKey: 378dc5...
17643 # Your private encryption key. DO NOT share this with anyone!
17644 EncryptionPrivateKey: 0777...
17646 # Your public signing key. You should not ordinarily need to share
17647 # this with anyone.
17648 SigningPublicKey: e1664...
17650 # Your private signing key. DO NOT share this with anyone!
17651 SigningPrivateKey: 0589d...
17656 @deftp {Data Type} yggdrasil-configuration
17657 Data type representing the configuration of Yggdrasil.
17660 @item @code{package} (default: @code{yggdrasil})
17661 Package object of Yggdrasil.
17663 @item @code{json-config} (default: @code{'()})
17664 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17665 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17666 the Guix store, which is readable to all users. @strong{Do not store your
17667 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17668 quick overview of valid keys and their default values.
17670 @item @code{autoconf?} (default: @code{#f})
17671 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17672 and peer with IPv6 neighbors.
17674 @item @code{log-level} (default: @code{'info})
17675 How much detail to include in logs. Use @code{'debug} for more detail.
17677 @item @code{log-to} (default: @code{'stdout})
17678 Where to send logs. By default, the service logs standard output to
17679 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17680 sends output to the running syslog service.
17682 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17683 What HJSON file to load sensitive data from. This is where private keys
17684 should be stored, which are necessary to specify if you don't want a
17685 randomized address after each restart. Use @code{#f} to disable. Options
17686 defined in this file take precedence over @code{json-config}. Use the output
17687 of @code{yggdrasil -genconf} as a starting point. To configure a static
17688 address, delete everything except these options:
17691 @item @code{EncryptionPublicKey}
17692 @item @code{EncryptionPrivateKey}
17693 @item @code{SigningPublicKey}
17694 @item @code{SigningPrivateKey}
17700 @defvr {Scheme Variable} ipfs-service-type
17701 The service type for connecting to the @uref{https://ipfs.io,IPFS network},
17702 a global, versioned, peer-to-peer file system. Pass it a
17703 @code{ipfs-configuration} to change the ports used for the gateway and API.
17705 Here's an example configuration, using some non-standard ports:
17708 (service ipfs-service-type
17709 (ipfs-configuration
17710 (gateway "/ip4/127.0.0.1/tcp/8880")
17711 (api "/ip4/127.0.0.1/tcp/8881")))
17715 @deftp {Data Type} ipfs-configuration
17716 Data type representing the configuration of IPFS.
17719 @item @code{package} (default: @code{go-ipfs})
17720 Package object of IPFS.
17722 @item @code{gateway} (default: @code{"/ip4/127.0.0.1/tcp/8082"})
17723 Address of the gateway, in ‘multiaddress’ format.
17725 @item @code{api} (default: @code{"/ip4/127.0.0.1/tcp/5001"})
17726 Address of the API endpoint, in ‘multiaddress’ format.
17731 @deffn {Scheme Variable} keepalived-service-type
17732 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
17733 routing software, @command{keepalived}. Its value must be an
17734 @code{keepalived-configuration} record as in this example for master
17738 (service keepalived-service-type
17739 (keepalived-configuration
17740 (config-file (local-file "keepalived-master.conf"))))
17743 where @file{keepalived-master.conf}:
17746 vrrp_instance my-group @{
17749 virtual_router_id 100
17751 unicast_peer @{ 10.0.0.2 @}
17752 virtual_ipaddress @{
17758 and for backup machine:
17761 (service keepalived-service-type
17762 (keepalived-configuration
17763 (config-file (local-file "keepalived-backup.conf"))))
17766 where @file{keepalived-backup.conf}:
17769 vrrp_instance my-group @{
17772 virtual_router_id 100
17774 unicast_peer @{ 10.0.0.3 @}
17775 virtual_ipaddress @{
17782 @node Unattended Upgrades
17783 @subsection Unattended Upgrades
17785 @cindex unattended upgrades
17786 @cindex upgrades, unattended
17787 Guix provides a service to perform @emph{unattended upgrades}:
17788 periodically, the system automatically reconfigures itself from the
17789 latest Guix. Guix System has several properties that make unattended
17794 upgrades are transactional (either the upgrade succeeds or it fails, but
17795 you cannot end up with an ``in-between'' system state);
17797 the upgrade log is kept---you can view it with @command{guix system
17798 list-generations}---and you can roll back to any previous generation,
17799 should the upgraded system fail to behave as intended;
17801 channel code is authenticated so you know you can only run genuine code
17802 (@pxref{Channels});
17804 @command{guix system reconfigure} prevents downgrades, which makes it
17805 immune to @dfn{downgrade attacks}.
17808 To set up unattended upgrades, add an instance of
17809 @code{unattended-upgrade-service-type} like the one below to the list of
17810 your operating system services:
17813 (service unattended-upgrade-service-type)
17816 The defaults above set up weekly upgrades: every Sunday at midnight.
17817 You do not need to provide the operating system configuration file: it
17818 uses @file{/run/current-system/configuration.scm}, which ensures it
17819 always uses your latest configuration---@pxref{provenance-service-type},
17820 for more information about this file.
17822 There are several things that can be configured, in particular the
17823 periodicity and services (daemons) to be restarted upon completion.
17824 When the upgrade is successful, the service takes care of deleting
17825 system generations older that some threshold, as per @command{guix
17826 system delete-generations}. See the reference below for details.
17828 To ensure that upgrades are actually happening, you can run
17829 @command{guix system describe}. To investigate upgrade failures, visit
17830 the unattended upgrade log file (see below).
17832 @defvr {Scheme Variable} unattended-upgrade-service-type
17833 This is the service type for unattended upgrades. It sets up an mcron
17834 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17835 reconfigure} from the latest version of the specified channels.
17837 Its value must be a @code{unattended-upgrade-configuration} record (see
17841 @deftp {Data Type} unattended-upgrade-configuration
17842 This data type represents the configuration of the unattended upgrade
17843 service. The following fields are available:
17846 @item @code{schedule} (default: @code{"30 01 * * 0"})
17847 This is the schedule of upgrades, expressed as a gexp containing an
17848 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17849 mcron, GNU@tie{}mcron}).
17851 @item @code{channels} (default: @code{#~%default-channels})
17852 This gexp specifies the channels to use for the upgrade
17853 (@pxref{Channels}). By default, the tip of the official @code{guix}
17856 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17857 This field specifies the operating system configuration file to use.
17858 The default is to reuse the config file of the current configuration.
17860 There are cases, though, where referring to
17861 @file{/run/current-system/configuration.scm} is not enough, for instance
17862 because that file refers to extra files (SSH public keys, extra
17863 configuration files, etc.) @i{via} @code{local-file} and similar
17864 constructs. For those cases, we recommend something along these lines:
17867 (unattended-upgrade-configuration
17868 (operating-system-file
17869 (file-append (local-file "." "config-dir" #:recursive? #t)
17873 The effect here is to import all of the current directory into the
17874 store, and to refer to @file{config.scm} within that directory.
17875 Therefore, uses of @code{local-file} within @file{config.scm} will work
17876 as expected. @xref{G-Expressions}, for information about
17877 @code{local-file} and @code{file-append}.
17879 @item @code{services-to-restart} (default: @code{'(mcron)})
17880 This field specifies the Shepherd services to restart when the upgrade
17883 Those services are restarted right away upon completion, as with
17884 @command{herd restart}, which ensures that the latest version is
17885 running---remember that by default @command{guix system reconfigure}
17886 only restarts services that are not currently running, which is
17887 conservative: it minimizes disruption but leaves outdated services
17890 Use @command{herd status} to find out candidates for restarting.
17891 @xref{Services}, for general information about services. Common
17892 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17894 By default, the @code{mcron} service is restarted. This ensures that
17895 the latest version of the unattended upgrade job will be used next time.
17897 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17898 This is the expiration time in seconds for system generations. System
17899 generations older that this amount of time are deleted with
17900 @command{guix system delete-generations} when an upgrade completes.
17903 The unattended upgrade service does not run the garbage collector. You
17904 will probably want to set up your own mcron job to run @command{guix gc}
17908 @item @code{maximum-duration} (default: @code{3600})
17909 Maximum duration in seconds for the upgrade; past that time, the upgrade
17912 This is primarily useful to ensure the upgrade does not end up
17913 rebuilding or re-downloading ``the world''.
17915 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17916 File where unattended upgrades are logged.
17921 @subsection X Window
17924 @cindex X Window System
17925 @cindex login manager
17926 Support for the X Window graphical display system---specifically
17927 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17928 there is no @code{xorg-service} procedure. Instead, the X server is
17929 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17932 @cindex GNOME, login manager
17933 GDM of course allows users to log in into window managers and desktop
17934 environments other than GNOME; for those using GNOME, GDM is required for
17935 features such as automatic screen locking.
17937 @cindex window manager
17938 To use X11, you must install at least one @dfn{window manager}---for
17939 example the @code{windowmaker} or @code{openbox} packages---preferably
17940 by adding it to the @code{packages} field of your operating system
17941 definition (@pxref{operating-system Reference, system-wide packages}).
17943 @defvr {Scheme Variable} gdm-service-type
17944 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17945 Desktop Manager} (GDM), a program that manages graphical display servers and
17946 handles graphical user logins. Its value must be a @code{gdm-configuration}
17949 @cindex session types (X11)
17950 @cindex X11 session types
17951 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17952 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17953 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17954 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17955 set of packages automatically makes them available at the log-in screen.
17957 In addition, @file{~/.xsession} files are honored. When available,
17958 @file{~/.xsession} must be an executable that starts a window manager
17959 and/or other X clients.
17962 @deftp {Data Type} gdm-configuration
17964 @item @code{auto-login?} (default: @code{#f})
17965 @itemx @code{default-user} (default: @code{#f})
17966 When @code{auto-login?} is false, GDM presents a log-in screen.
17968 When @code{auto-login?} is true, GDM logs in directly as
17969 @code{default-user}.
17971 @item @code{debug?} (default: @code{#f})
17972 When true, GDM writes debug messages to its log.
17974 @item @code{gnome-shell-assets} (default: ...)
17975 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17977 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17978 Configuration of the Xorg graphical server.
17980 @item @code{xsession} (default: @code{(xinitrc)})
17981 Script to run before starting a X session.
17983 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17984 File name of the @code{dbus-daemon} executable.
17986 @item @code{gdm} (default: @code{gdm})
17987 The GDM package to use.
17991 @defvr {Scheme Variable} slim-service-type
17992 This is the type for the SLiM graphical login manager for X11.
17994 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17995 allows users to choose a session from the log-in screen using @kbd{F1}. It
17996 also honors @file{~/.xsession} files.
17998 Unlike GDM, SLiM does not spawn the user session on a different VT after
17999 logging in, which means that you can only start one graphical session. If you
18000 want to be able to run multiple graphical sessions at the same time you have
18001 to add multiple SLiM services to your system services. The following example
18002 shows how to replace the default GDM service with two SLiM services on tty7
18006 (use-modules (gnu services)
18007 (gnu services desktop)
18008 (gnu services xorg)
18009 (srfi srfi-1)) ;for 'remove'
18013 (services (cons* (service slim-service-type (slim-configuration
18016 (service slim-service-type (slim-configuration
18019 (modify-services %desktop-services
18020 (delete gdm-service-type)))))
18025 @deftp {Data Type} slim-configuration
18026 Data type representing the configuration of @code{slim-service-type}.
18029 @item @code{allow-empty-passwords?} (default: @code{#t})
18030 Whether to allow logins with empty passwords.
18032 @item @code{auto-login?} (default: @code{#f})
18033 @itemx @code{default-user} (default: @code{""})
18034 When @code{auto-login?} is false, SLiM presents a log-in screen.
18036 When @code{auto-login?} is true, SLiM logs in directly as
18037 @code{default-user}.
18039 @item @code{theme} (default: @code{%default-slim-theme})
18040 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
18041 The graphical theme to use and its name.
18043 @item @code{auto-login-session} (default: @code{#f})
18044 If true, this must be the name of the executable to start as the default
18045 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
18047 If false, a session described by one of the available @file{.desktop}
18048 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
18052 You must install at least one window manager in the system profile or in
18053 your user profile. Failing to do that, if @code{auto-login-session} is
18054 false, you will be unable to log in.
18057 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
18058 Configuration of the Xorg graphical server.
18060 @item @code{display} (default @code{":0"})
18061 The display on which to start the Xorg graphical server.
18063 @item @code{vt} (default @code{"vt7"})
18064 The VT on which to start the Xorg graphical server.
18066 @item @code{xauth} (default: @code{xauth})
18067 The XAuth package to use.
18069 @item @code{shepherd} (default: @code{shepherd})
18070 The Shepherd package used when invoking @command{halt} and
18073 @item @code{sessreg} (default: @code{sessreg})
18074 The sessreg package used in order to register the session.
18076 @item @code{slim} (default: @code{slim})
18077 The SLiM package to use.
18081 @defvr {Scheme Variable} %default-theme
18082 @defvrx {Scheme Variable} %default-theme-name
18083 The default SLiM theme and its name.
18087 @deftp {Data Type} sddm-configuration
18088 This is the data type representing the SDDM service configuration.
18091 @item @code{display-server} (default: "x11")
18092 Select display server to use for the greeter. Valid values are
18093 @samp{"x11"} or @samp{"wayland"}.
18095 @item @code{numlock} (default: "on")
18096 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
18098 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
18099 Command to run when halting.
18101 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
18102 Command to run when rebooting.
18104 @item @code{theme} (default "maldives")
18105 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
18106 @samp{"maldives"} or @samp{"maya"}.
18108 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
18109 Directory to look for themes.
18111 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
18112 Directory to look for faces.
18114 @item @code{default-path} (default "/run/current-system/profile/bin")
18115 Default PATH to use.
18117 @item @code{minimum-uid} (default: 1000)
18118 Minimum UID displayed in SDDM and allowed for log-in.
18120 @item @code{maximum-uid} (default: 2000)
18121 Maximum UID to display in SDDM.
18123 @item @code{remember-last-user?} (default #t)
18124 Remember last user.
18126 @item @code{remember-last-session?} (default #t)
18127 Remember last session.
18129 @item @code{hide-users} (default "")
18130 Usernames to hide from SDDM greeter.
18132 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
18133 Users with shells listed will be hidden from the SDDM greeter.
18135 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
18136 Script to run before starting a wayland session.
18138 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
18139 Directory to look for desktop files starting wayland sessions.
18141 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
18142 Configuration of the Xorg graphical server.
18144 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
18147 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
18150 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
18151 Script to run after starting xorg-server.
18153 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
18154 Script to run before stopping xorg-server.
18156 @item @code{xsession-command} (default: @code{xinitrc})
18157 Script to run before starting a X session.
18159 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
18160 Directory to look for desktop files starting X sessions.
18162 @item @code{minimum-vt} (default: 7)
18165 @item @code{auto-login-user} (default "")
18166 User to use for auto-login.
18168 @item @code{auto-login-session} (default "")
18169 Desktop file to use for auto-login.
18171 @item @code{relogin?} (default #f)
18172 Relogin after logout.
18177 @cindex login manager
18179 @defvr {Scheme Variable} sddm-service-type
18180 This is the type of the service to run the
18181 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
18182 must be a @code{sddm-configuration} record (see below).
18184 Here's an example use:
18187 (service sddm-service-type
18188 (sddm-configuration
18189 (auto-login-user "alice")
18190 (auto-login-session "xfce.desktop")))
18194 @deftp {Data Type} sddm-configuration
18195 This data type represents the configuration of the SDDM login manager.
18196 The available fields are:
18199 @item @code{sddm} (default: @code{sddm})
18200 The SDDM package to use.
18202 @item @code{display-server} (default: @code{"x11"})
18203 This must be either @code{"x11"} or @code{"wayland"}.
18205 @c FIXME: Add more fields.
18207 @item @code{auto-login-user} (default: @code{""})
18208 If non-empty, this is the user account under which to log in
18211 @item @code{auto-login-session} (default: @code{""})
18212 If non-empty, this is the @file{.desktop} file name to use as the
18213 auto-login session.
18217 @cindex Xorg, configuration
18218 @deftp {Data Type} xorg-configuration
18219 This data type represents the configuration of the Xorg graphical display
18220 server. Note that there is no Xorg service; instead, the X server is started
18221 by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
18222 of these display managers aggregates an @code{xorg-configuration} record.
18225 @item @code{modules} (default: @code{%default-xorg-modules})
18226 This is a list of @dfn{module packages} loaded by the Xorg
18227 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
18229 @item @code{fonts} (default: @code{%default-xorg-fonts})
18230 This is a list of font directories to add to the server's @dfn{font path}.
18232 @item @code{drivers} (default: @code{'()})
18233 This must be either the empty list, in which case Xorg chooses a graphics
18234 driver automatically, or a list of driver names that will be tried in this
18235 order---e.g., @code{("modesetting" "vesa")}.
18237 @item @code{resolutions} (default: @code{'()})
18238 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
18239 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
18242 @cindex keyboard layout, for Xorg
18243 @cindex keymap, for Xorg
18244 @item @code{keyboard-layout} (default: @code{#f})
18245 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
18246 English (``qwerty'') for a 105-key PC keyboard.
18248 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
18249 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
18250 information on how to specify the keyboard layout.
18252 @item @code{extra-config} (default: @code{'()})
18253 This is a list of strings or objects appended to the configuration file. It
18254 is used to pass extra text to be added verbatim to the configuration file.
18256 @item @code{server} (default: @code{xorg-server})
18257 This is the package providing the Xorg server.
18259 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
18260 This is the list of command-line arguments to pass to the X server. The
18261 default is @code{-nolisten tcp}.
18265 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
18266 [@var{login-manager-service-type}]
18267 Tell the log-in manager (of type @var{login-manager-service-type}) to use
18268 @var{config}, an @code{<xorg-configuration>} record.
18270 Since the Xorg configuration is embedded in the log-in manager's
18271 configuration---e.g., @code{gdm-configuration}---this procedure provides a
18272 shorthand to set the Xorg configuration.
18275 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
18276 Return a @code{startx} script in which the modules, fonts, etc. specified
18277 in @var{config}, are available. The result should be used in place of
18280 Usually the X server is started by a login manager.
18284 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
18285 Add @var{package}, a package for a screen locker or screen saver whose
18286 command is @var{program}, to the set of setuid programs and add a PAM entry
18287 for it. For example:
18290 (screen-locker-service xlockmore "xlock")
18293 makes the good ol' XlockMore usable.
18297 @node Printing Services
18298 @subsection Printing Services
18300 @cindex printer support with CUPS
18301 The @code{(gnu services cups)} module provides a Guix service definition
18302 for the CUPS printing service. To add printer support to a Guix
18303 system, add a @code{cups-service} to the operating system definition:
18305 @deffn {Scheme Variable} cups-service-type
18306 The service type for the CUPS print server. Its value should be a valid
18307 CUPS configuration (see below). To use the default settings, simply
18310 (service cups-service-type)
18314 The CUPS configuration controls the basic things about your CUPS
18315 installation: what interfaces it listens on, what to do if a print job
18316 fails, how much logging to do, and so on. To actually add a printer,
18317 you have to visit the @url{http://localhost:631} URL, or use a tool such
18318 as GNOME's printer configuration services. By default, configuring a
18319 CUPS service will generate a self-signed certificate if needed, for
18320 secure connections to the print server.
18322 Suppose you want to enable the Web interface of CUPS and also add
18323 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
18324 package and for HP printers @i{via} the @code{hplip-minimal} package.
18325 You can do that directly, like this (you need to use the
18326 @code{(gnu packages cups)} module):
18329 (service cups-service-type
18330 (cups-configuration
18331 (web-interface? #t)
18333 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
18336 Note: If you wish to use the Qt5 based GUI which comes with the hplip
18337 package then it is suggested that you install the @code{hplip} package,
18338 either in your OS configuration file or as your user.
18340 The available configuration parameters follow. Each parameter
18341 definition is preceded by its type; for example, @samp{string-list foo}
18342 indicates that the @code{foo} parameter should be specified as a list of
18343 strings. There is also a way to specify the configuration as a string,
18344 if you have an old @code{cupsd.conf} file that you want to port over
18345 from some other system; see the end for more details.
18347 @c The following documentation was initially generated by
18348 @c (generate-documentation) in (gnu services cups). Manually maintained
18349 @c documentation is better, so we shouldn't hesitate to edit below as
18350 @c needed. However if the change you want to make to this documentation
18351 @c can be done in an automated way, it's probably easier to change
18352 @c (generate-documentation) than to make it below and have to deal with
18353 @c the churn as CUPS updates.
18356 Available @code{cups-configuration} fields are:
18358 @deftypevr {@code{cups-configuration} parameter} package cups
18362 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
18363 Drivers and other extensions to the CUPS package.
18366 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
18367 Configuration of where to write logs, what directories to use for print
18368 spools, and related privileged configuration parameters.
18370 Available @code{files-configuration} fields are:
18372 @deftypevr {@code{files-configuration} parameter} log-location access-log
18373 Defines the access log filename. Specifying a blank filename disables
18374 access log generation. The value @code{stderr} causes log entries to be
18375 sent to the standard error file when the scheduler is running in the
18376 foreground, or to the system log daemon when run in the background. The
18377 value @code{syslog} causes log entries to be sent to the system log
18378 daemon. The server name may be included in filenames using the string
18379 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
18381 Defaults to @samp{"/var/log/cups/access_log"}.
18384 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
18385 Where CUPS should cache data.
18387 Defaults to @samp{"/var/cache/cups"}.
18390 @deftypevr {@code{files-configuration} parameter} string config-file-perm
18391 Specifies the permissions for all configuration files that the scheduler
18394 Note that the permissions for the printers.conf file are currently
18395 masked to only allow access from the scheduler user (typically root).
18396 This is done because printer device URIs sometimes contain sensitive
18397 authentication information that should not be generally known on the
18398 system. There is no way to disable this security feature.
18400 Defaults to @samp{"0640"}.
18403 @deftypevr {@code{files-configuration} parameter} log-location error-log
18404 Defines the error log filename. Specifying a blank filename disables
18405 error log generation. The value @code{stderr} causes log entries to be
18406 sent to the standard error file when the scheduler is running in the
18407 foreground, or to the system log daemon when run in the background. The
18408 value @code{syslog} causes log entries to be sent to the system log
18409 daemon. The server name may be included in filenames using the string
18410 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
18412 Defaults to @samp{"/var/log/cups/error_log"}.
18415 @deftypevr {@code{files-configuration} parameter} string fatal-errors
18416 Specifies which errors are fatal, causing the scheduler to exit. The
18421 No errors are fatal.
18424 All of the errors below are fatal.
18427 Browsing initialization errors are fatal, for example failed connections
18428 to the DNS-SD daemon.
18431 Configuration file syntax errors are fatal.
18434 Listen or Port errors are fatal, except for IPv6 failures on the
18435 loopback or @code{any} addresses.
18438 Log file creation or write errors are fatal.
18441 Bad startup file permissions are fatal, for example shared TLS
18442 certificate and key files with world-read permissions.
18445 Defaults to @samp{"all -browse"}.
18448 @deftypevr {@code{files-configuration} parameter} boolean file-device?
18449 Specifies whether the file pseudo-device can be used for new printer
18450 queues. The URI @uref{file:///dev/null} is always allowed.
18452 Defaults to @samp{#f}.
18455 @deftypevr {@code{files-configuration} parameter} string group
18456 Specifies the group name or ID that will be used when executing external
18459 Defaults to @samp{"lp"}.
18462 @deftypevr {@code{files-configuration} parameter} string log-file-perm
18463 Specifies the permissions for all log files that the scheduler writes.
18465 Defaults to @samp{"0644"}.
18468 @deftypevr {@code{files-configuration} parameter} log-location page-log
18469 Defines the page log filename. Specifying a blank filename disables
18470 page log generation. The value @code{stderr} causes log entries to be
18471 sent to the standard error file when the scheduler is running in the
18472 foreground, or to the system log daemon when run in the background. The
18473 value @code{syslog} causes log entries to be sent to the system log
18474 daemon. The server name may be included in filenames using the string
18475 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
18477 Defaults to @samp{"/var/log/cups/page_log"}.
18480 @deftypevr {@code{files-configuration} parameter} string remote-root
18481 Specifies the username that is associated with unauthenticated accesses
18482 by clients claiming to be the root user. The default is @code{remroot}.
18484 Defaults to @samp{"remroot"}.
18487 @deftypevr {@code{files-configuration} parameter} file-name request-root
18488 Specifies the directory that contains print jobs and other HTTP request
18491 Defaults to @samp{"/var/spool/cups"}.
18494 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
18495 Specifies the level of security sandboxing that is applied to print
18496 filters, backends, and other child processes of the scheduler; either
18497 @code{relaxed} or @code{strict}. This directive is currently only
18498 used/supported on macOS.
18500 Defaults to @samp{strict}.
18503 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
18504 Specifies the location of TLS certificates and private keys. CUPS will
18505 look for public and private keys in this directory: @file{.crt} files
18506 for PEM-encoded certificates and corresponding @file{.key} files for
18507 PEM-encoded private keys.
18509 Defaults to @samp{"/etc/cups/ssl"}.
18512 @deftypevr {@code{files-configuration} parameter} file-name server-root
18513 Specifies the directory containing the server configuration files.
18515 Defaults to @samp{"/etc/cups"}.
18518 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
18519 Specifies whether the scheduler calls fsync(2) after writing
18520 configuration or state files.
18522 Defaults to @samp{#f}.
18525 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
18526 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
18529 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
18530 Specifies the directory where temporary files are stored.
18532 Defaults to @samp{"/var/spool/cups/tmp"}.
18535 @deftypevr {@code{files-configuration} parameter} string user
18536 Specifies the user name or ID that is used when running external
18539 Defaults to @samp{"lp"}.
18542 @deftypevr {@code{files-configuration} parameter} string set-env
18543 Set the specified environment variable to be passed to child processes.
18545 Defaults to @samp{"variable value"}.
18549 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
18550 Specifies the logging level for the AccessLog file. The @code{config}
18551 level logs when printers and classes are added, deleted, or modified and
18552 when configuration files are accessed or updated. The @code{actions}
18553 level logs when print jobs are submitted, held, released, modified, or
18554 canceled, and any of the conditions for @code{config}. The @code{all}
18555 level logs all requests.
18557 Defaults to @samp{actions}.
18560 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
18561 Specifies whether to purge job history data automatically when it is no
18562 longer required for quotas.
18564 Defaults to @samp{#f}.
18567 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
18568 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
18569 For example, @samp{"_cups" "_print"} will tell network clients that both
18570 CUPS sharing and IPP Everywhere are supported.
18572 Defaults to @samp{"_cups"}.
18575 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
18576 Specifies which protocols to use for local printer sharing.
18578 Defaults to @samp{dnssd}.
18581 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
18582 Specifies whether the CUPS web interface is advertised.
18584 Defaults to @samp{#f}.
18587 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
18588 Specifies whether shared printers are advertised.
18590 Defaults to @samp{#f}.
18593 @deftypevr {@code{cups-configuration} parameter} string classification
18594 Specifies the security classification of the server. Any valid banner
18595 name can be used, including @samp{"classified"}, @samp{"confidential"},
18596 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
18597 banner can be omitted to disable secure printing functions.
18599 Defaults to @samp{""}.
18602 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
18603 Specifies whether users may override the classification (cover page) of
18604 individual print jobs using the @code{job-sheets} option.
18606 Defaults to @samp{#f}.
18609 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
18610 Specifies the default type of authentication to use.
18612 Defaults to @samp{Basic}.
18615 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
18616 Specifies whether encryption will be used for authenticated requests.
18618 Defaults to @samp{Required}.
18621 @deftypevr {@code{cups-configuration} parameter} string default-language
18622 Specifies the default language to use for text and web content.
18624 Defaults to @samp{"en"}.
18627 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
18628 Specifies the default paper size for new print queues. @samp{"Auto"}
18629 uses a locale-specific default, while @samp{"None"} specifies there is
18630 no default paper size. Specific size names are typically
18631 @samp{"Letter"} or @samp{"A4"}.
18633 Defaults to @samp{"Auto"}.
18636 @deftypevr {@code{cups-configuration} parameter} string default-policy
18637 Specifies the default access policy to use.
18639 Defaults to @samp{"default"}.
18642 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
18643 Specifies whether local printers are shared by default.
18645 Defaults to @samp{#t}.
18648 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
18649 Specifies the delay for updating of configuration and state files, in
18650 seconds. A value of 0 causes the update to happen as soon as possible,
18651 typically within a few milliseconds.
18653 Defaults to @samp{30}.
18656 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18657 Specifies what to do when an error occurs. Possible values are
18658 @code{abort-job}, which will discard the failed print job;
18659 @code{retry-job}, which will retry the job at a later time;
18660 @code{retry-current-job}, which retries the failed job immediately; and
18661 @code{stop-printer}, which stops the printer.
18663 Defaults to @samp{stop-printer}.
18666 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18667 Specifies the maximum cost of filters that are run concurrently, which
18668 can be used to minimize disk, memory, and CPU resource problems. A
18669 limit of 0 disables filter limiting. An average print to a
18670 non-PostScript printer needs a filter limit of about 200. A PostScript
18671 printer needs about half that (100). Setting the limit below these
18672 thresholds will effectively limit the scheduler to printing a single job
18675 Defaults to @samp{0}.
18678 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18679 Specifies the scheduling priority of filters that are run to print a
18680 job. The nice value ranges from 0, the highest priority, to 19, the
18683 Defaults to @samp{0}.
18686 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18687 Specifies whether to do reverse lookups on connecting clients. The
18688 @code{double} setting causes @code{cupsd} to verify that the hostname
18689 resolved from the address matches one of the addresses returned for that
18690 hostname. Double lookups also prevent clients with unregistered
18691 addresses from connecting to your server. Only set this option to
18692 @code{#t} or @code{double} if absolutely required.
18694 Defaults to @samp{#f}.
18697 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18698 Specifies the number of seconds to wait before killing the filters and
18699 backend associated with a canceled or held job.
18701 Defaults to @samp{30}.
18704 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18705 Specifies the interval between retries of jobs in seconds. This is
18706 typically used for fax queues but can also be used with normal print
18707 queues whose error policy is @code{retry-job} or
18708 @code{retry-current-job}.
18710 Defaults to @samp{30}.
18713 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18714 Specifies the number of retries that are done for jobs. This is
18715 typically used for fax queues but can also be used with normal print
18716 queues whose error policy is @code{retry-job} or
18717 @code{retry-current-job}.
18719 Defaults to @samp{5}.
18722 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18723 Specifies whether to support HTTP keep-alive connections.
18725 Defaults to @samp{#t}.
18728 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18729 Specifies the maximum size of print files, IPP requests, and HTML form
18730 data. A limit of 0 disables the limit check.
18732 Defaults to @samp{0}.
18735 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18736 Listens on the specified interfaces for connections. Valid values are
18737 of the form @var{address}:@var{port}, where @var{address} is either an
18738 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18739 indicate all addresses. Values can also be file names of local UNIX
18740 domain sockets. The Listen directive is similar to the Port directive
18741 but allows you to restrict access to specific interfaces or networks.
18744 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18745 Specifies the number of pending connections that will be allowed. This
18746 normally only affects very busy servers that have reached the MaxClients
18747 limit, but can also be triggered by large numbers of simultaneous
18748 connections. When the limit is reached, the operating system will
18749 refuse additional connections until the scheduler can accept the pending
18752 Defaults to @samp{128}.
18755 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18756 Specifies a set of additional access controls.
18758 Available @code{location-access-controls} fields are:
18760 @deftypevr {@code{location-access-controls} parameter} file-name path
18761 Specifies the URI path to which the access control applies.
18764 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18765 Access controls for all access to this path, in the same format as the
18766 @code{access-controls} of @code{operation-access-control}.
18768 Defaults to @samp{()}.
18771 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18772 Access controls for method-specific access to this path.
18774 Defaults to @samp{()}.
18776 Available @code{method-access-controls} fields are:
18778 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18779 If @code{#t}, apply access controls to all methods except the listed
18780 methods. Otherwise apply to only the listed methods.
18782 Defaults to @samp{#f}.
18785 @deftypevr {@code{method-access-controls} parameter} method-list methods
18786 Methods to which this access control applies.
18788 Defaults to @samp{()}.
18791 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18792 Access control directives, as a list of strings. Each string should be
18793 one directive, such as @samp{"Order allow,deny"}.
18795 Defaults to @samp{()}.
18800 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18801 Specifies the number of debugging messages that are retained for logging
18802 if an error occurs in a print job. Debug messages are logged regardless
18803 of the LogLevel setting.
18805 Defaults to @samp{100}.
18808 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18809 Specifies the level of logging for the ErrorLog file. The value
18810 @code{none} stops all logging while @code{debug2} logs everything.
18812 Defaults to @samp{info}.
18815 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18816 Specifies the format of the date and time in the log files. The value
18817 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18819 Defaults to @samp{standard}.
18822 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18823 Specifies the maximum number of simultaneous clients that are allowed by
18826 Defaults to @samp{100}.
18829 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18830 Specifies the maximum number of simultaneous clients that are allowed
18831 from a single address.
18833 Defaults to @samp{100}.
18836 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18837 Specifies the maximum number of copies that a user can print of each
18840 Defaults to @samp{9999}.
18843 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18844 Specifies the maximum time a job may remain in the @code{indefinite}
18845 hold state before it is canceled. A value of 0 disables cancellation of
18848 Defaults to @samp{0}.
18851 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18852 Specifies the maximum number of simultaneous jobs that are allowed. Set
18853 to 0 to allow an unlimited number of jobs.
18855 Defaults to @samp{500}.
18858 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18859 Specifies the maximum number of simultaneous jobs that are allowed per
18860 printer. A value of 0 allows up to MaxJobs jobs per printer.
18862 Defaults to @samp{0}.
18865 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18866 Specifies the maximum number of simultaneous jobs that are allowed per
18867 user. A value of 0 allows up to MaxJobs jobs per user.
18869 Defaults to @samp{0}.
18872 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18873 Specifies the maximum time a job may take to print before it is
18874 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18876 Defaults to @samp{10800}.
18879 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18880 Specifies the maximum size of the log files before they are rotated, in
18881 bytes. The value 0 disables log rotation.
18883 Defaults to @samp{1048576}.
18886 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18887 Specifies the maximum amount of time to allow between files in a
18888 multiple file print job, in seconds.
18890 Defaults to @samp{300}.
18893 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18894 Specifies the format of PageLog lines. Sequences beginning with percent
18895 (@samp{%}) characters are replaced with the corresponding information,
18896 while all other characters are copied literally. The following percent
18897 sequences are recognized:
18901 insert a single percent character
18904 insert the value of the specified IPP attribute
18907 insert the number of copies for the current page
18910 insert the current page number
18913 insert the current date and time in common log format
18919 insert the printer name
18922 insert the username
18925 A value of the empty string disables page logging. The string @code{%p
18926 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18927 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18930 Defaults to @samp{""}.
18933 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18934 Passes the specified environment variable(s) to child processes; a list
18937 Defaults to @samp{()}.
18940 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18941 Specifies named access control policies.
18943 Available @code{policy-configuration} fields are:
18945 @deftypevr {@code{policy-configuration} parameter} string name
18946 Name of the policy.
18949 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18950 Specifies an access list for a job's private values. @code{@@ACL} maps
18951 to the printer's requesting-user-name-allowed or
18952 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18953 owner. @code{@@SYSTEM} maps to the groups listed for the
18954 @code{system-group} field of the @code{files-configuration},
18955 which is reified into the @code{cups-files.conf(5)} file. Other
18956 possible elements of the access list include specific user names, and
18957 @code{@@@var{group}} to indicate members of a specific group. The
18958 access list may also be simply @code{all} or @code{default}.
18960 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18963 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18964 Specifies the list of job values to make private, or @code{all},
18965 @code{default}, or @code{none}.
18967 Defaults to @samp{"job-name job-originating-host-name
18968 job-originating-user-name phone"}.
18971 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18972 Specifies an access list for a subscription's private values.
18973 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18974 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18975 owner. @code{@@SYSTEM} maps to the groups listed for the
18976 @code{system-group} field of the @code{files-configuration},
18977 which is reified into the @code{cups-files.conf(5)} file. Other
18978 possible elements of the access list include specific user names, and
18979 @code{@@@var{group}} to indicate members of a specific group. The
18980 access list may also be simply @code{all} or @code{default}.
18982 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18985 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18986 Specifies the list of job values to make private, or @code{all},
18987 @code{default}, or @code{none}.
18989 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18990 notify-subscriber-user-name notify-user-data"}.
18993 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18994 Access control by IPP operation.
18996 Defaults to @samp{()}.
19000 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
19001 Specifies whether job files (documents) are preserved after a job is
19002 printed. If a numeric value is specified, job files are preserved for
19003 the indicated number of seconds after printing. Otherwise a boolean
19004 value applies indefinitely.
19006 Defaults to @samp{86400}.
19009 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
19010 Specifies whether the job history is preserved after a job is printed.
19011 If a numeric value is specified, the job history is preserved for the
19012 indicated number of seconds after printing. If @code{#t}, the job
19013 history is preserved until the MaxJobs limit is reached.
19015 Defaults to @samp{#t}.
19018 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
19019 Specifies the amount of time to wait for job completion before
19020 restarting the scheduler.
19022 Defaults to @samp{30}.
19025 @deftypevr {@code{cups-configuration} parameter} string rip-cache
19026 Specifies the maximum amount of memory to use when converting documents
19027 into bitmaps for a printer.
19029 Defaults to @samp{"128m"}.
19032 @deftypevr {@code{cups-configuration} parameter} string server-admin
19033 Specifies the email address of the server administrator.
19035 Defaults to @samp{"root@@localhost.localdomain"}.
19038 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
19039 The ServerAlias directive is used for HTTP Host header validation when
19040 clients connect to the scheduler from external interfaces. Using the
19041 special name @code{*} can expose your system to known browser-based DNS
19042 rebinding attacks, even when accessing sites through a firewall. If the
19043 auto-discovery of alternate names does not work, we recommend listing
19044 each alternate name with a ServerAlias directive instead of using
19047 Defaults to @samp{*}.
19050 @deftypevr {@code{cups-configuration} parameter} string server-name
19051 Specifies the fully-qualified host name of the server.
19053 Defaults to @samp{"localhost"}.
19056 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
19057 Specifies what information is included in the Server header of HTTP
19058 responses. @code{None} disables the Server header. @code{ProductOnly}
19059 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
19060 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
19061 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
19062 the output of the @code{uname} command. @code{Full} reports @code{CUPS
19063 2.0.0 (@var{uname}) IPP/2.0}.
19065 Defaults to @samp{Minimal}.
19068 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
19069 Listens on the specified interfaces for encrypted connections. Valid
19070 values are of the form @var{address}:@var{port}, where @var{address} is
19071 either an IPv6 address enclosed in brackets, an IPv4 address, or
19072 @code{*} to indicate all addresses.
19074 Defaults to @samp{()}.
19077 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
19078 Sets encryption options. By default, CUPS only supports encryption
19079 using TLS v1.0 or higher using known secure cipher suites. Security is
19080 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
19081 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
19082 suites, which are required for some older clients. The @code{AllowSSL3} option
19083 enables SSL v3.0, which is required for some older clients that do not support
19084 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
19085 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
19086 protocol version to TLS v1.1.
19088 Defaults to @samp{()}.
19091 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
19092 Specifies whether the scheduler requires clients to strictly adhere to
19093 the IPP specifications.
19095 Defaults to @samp{#f}.
19098 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
19099 Specifies the HTTP request timeout, in seconds.
19101 Defaults to @samp{300}.
19105 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
19106 Specifies whether the web interface is enabled.
19108 Defaults to @samp{#f}.
19111 At this point you're probably thinking ``oh dear, Guix manual, I like
19112 you but you can stop already with the configuration options''. Indeed.
19113 However, one more point: it could be that you have an existing
19114 @code{cupsd.conf} that you want to use. In that case, you can pass an
19115 @code{opaque-cups-configuration} as the configuration of a
19116 @code{cups-service-type}.
19118 Available @code{opaque-cups-configuration} fields are:
19120 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
19124 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
19125 The contents of the @code{cupsd.conf}, as a string.
19128 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
19129 The contents of the @code{cups-files.conf} file, as a string.
19132 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
19133 strings of the same name, you could instantiate a CUPS service like
19137 (service cups-service-type
19138 (opaque-cups-configuration
19139 (cupsd.conf cupsd.conf)
19140 (cups-files.conf cups-files.conf)))
19144 @node Desktop Services
19145 @subsection Desktop Services
19147 The @code{(gnu services desktop)} module provides services that are
19148 usually useful in the context of a ``desktop'' setup---that is, on a
19149 machine running a graphical display server, possibly with graphical user
19150 interfaces, etc. It also defines services that provide specific desktop
19151 environments like GNOME, Xfce or MATE.
19153 To simplify things, the module defines a variable containing the set of
19154 services that users typically expect on a machine with a graphical
19155 environment and networking:
19157 @defvr {Scheme Variable} %desktop-services
19158 This is a list of services that builds upon @code{%base-services} and
19159 adds or adjusts services for a typical ``desktop'' setup.
19161 In particular, it adds a graphical login manager (@pxref{X Window,
19162 @code{gdm-service-type}}), screen lockers, a network management tool
19163 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
19164 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
19165 energy and color management services, the @code{elogind} login and seat
19166 manager, the Polkit privilege service, the GeoClue location service, the
19167 AccountsService daemon that allows authorized users change system passwords,
19168 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
19169 name service switch service configured to be able to use @code{nss-mdns}
19170 (@pxref{Name Service Switch, mDNS}).
19173 The @code{%desktop-services} variable can be used as the @code{services}
19174 field of an @code{operating-system} declaration (@pxref{operating-system
19175 Reference, @code{services}}).
19177 Additionally, the @code{gnome-desktop-service-type},
19178 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
19179 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
19180 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
19181 ``add GNOME'' means that system-level services like the backlight adjustment
19182 helpers and the power management utilities are added to the system, extending
19183 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
19184 elevated privileges on a limited number of special-purpose system interfaces.
19185 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
19186 the GNOME metapackage to the system profile. Likewise, adding the Xfce
19187 service not only adds the @code{xfce} metapackage to the system profile, but
19188 it also gives the Thunar file manager the ability to open a ``root-mode'' file
19189 management window, if the user authenticates using the administrator's
19190 password via the standard polkit graphical interface. To ``add MATE'' means
19191 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
19192 to operate with elevated privileges on a limited number of special-purpose
19193 system interfaces. Additionally, adding a service of type
19194 @code{mate-desktop-service-type} adds the MATE metapackage to the system
19195 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
19196 appropriately, and several of Enlightenment's binaries are set as setuid,
19197 allowing Enlightenment's screen locker and other functionality to work as
19200 The desktop environments in Guix use the Xorg display server by
19201 default. If you'd like to use the newer display server protocol
19202 called Wayland, you need to use the @code{sddm-service} instead of
19203 GDM as the graphical login manager. You should then
19204 select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
19205 also try starting GNOME on Wayland manually from a TTY with the
19206 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
19207 gnome-session``. Currently only GNOME has support for Wayland.
19209 @defvr {Scheme Variable} gnome-desktop-service-type
19210 This is the type of the service that adds the @uref{https://www.gnome.org,
19211 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
19212 object (see below).
19214 This service adds the @code{gnome} package to the system profile, and extends
19215 polkit with the actions from @code{gnome-settings-daemon}.
19218 @deftp {Data Type} gnome-desktop-configuration
19219 Configuration record for the GNOME desktop environment.
19222 @item @code{gnome} (default: @code{gnome})
19223 The GNOME package to use.
19227 @defvr {Scheme Variable} xfce-desktop-service-type
19228 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
19229 desktop environment. Its value is an @code{xfce-desktop-configuration} object
19232 This service adds the @code{xfce} package to the system profile, and
19233 extends polkit with the ability for @code{thunar} to manipulate the file
19234 system as root from within a user session, after the user has authenticated
19235 with the administrator's password.
19237 Note that @code{xfce4-panel} and its plugin packages should be installed in
19238 the same profile to ensure compatibility. When using this service, you should
19239 add extra plugins (@code{xfce4-whiskermenu-plugin},
19240 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
19241 @code{operating-system}.
19244 @deftp {Data Type} xfce-desktop-configuration
19245 Configuration record for the Xfce desktop environment.
19248 @item @code{xfce} (default: @code{xfce})
19249 The Xfce package to use.
19253 @deffn {Scheme Variable} mate-desktop-service-type
19254 This is the type of the service that runs the @uref{https://mate-desktop.org/,
19255 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
19256 object (see below).
19258 This service adds the @code{mate} package to the system
19259 profile, and extends polkit with the actions from
19260 @code{mate-settings-daemon}.
19263 @deftp {Data Type} mate-desktop-configuration
19264 Configuration record for the MATE desktop environment.
19267 @item @code{mate} (default: @code{mate})
19268 The MATE package to use.
19272 @deffn {Scheme Variable} lxqt-desktop-service-type
19273 This is the type of the service that runs the @uref{https://lxqt-project.org,
19274 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
19275 object (see below).
19277 This service adds the @code{lxqt} package to the system
19281 @deftp {Data Type} lxqt-desktop-configuration
19282 Configuration record for the LXQt desktop environment.
19285 @item @code{lxqt} (default: @code{lxqt})
19286 The LXQT package to use.
19290 @deffn {Scheme Variable} enlightenment-desktop-service-type
19291 Return a service that adds the @code{enlightenment} package to the system
19292 profile, and extends dbus with actions from @code{efl}.
19295 @deftp {Data Type} enlightenment-desktop-service-configuration
19297 @item @code{enlightenment} (default: @code{enlightenment})
19298 The enlightenment package to use.
19302 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
19303 the default @code{%desktop-services} variable doesn't include any of
19304 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
19305 @code{%desktop-services} in the @code{services} field of your
19306 @code{operating-system}:
19309 (use-modules (gnu))
19310 (use-service-modules desktop)
19313 ;; cons* adds items to the list given as its last argument.
19314 (services (cons* (service gnome-desktop-service-type)
19315 (service xfce-desktop-service)
19316 %desktop-services))
19320 These desktop environments will then be available as options in the
19321 graphical login window.
19323 The actual service definitions included in @code{%desktop-services} and
19324 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
19325 are described below.
19327 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
19328 Return a service that runs the ``system bus'', using @var{dbus}, with
19329 support for @var{services}.
19331 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
19332 facility. Its system bus is used to allow system services to communicate
19333 and to be notified of system-wide events.
19335 @var{services} must be a list of packages that provide an
19336 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
19337 and policy files. For example, to allow avahi-daemon to use the system bus,
19338 @var{services} must be equal to @code{(list avahi)}.
19341 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
19342 Return a service that runs the @code{elogind} login and
19343 seat management daemon. @uref{https://github.com/elogind/elogind,
19344 Elogind} exposes a D-Bus interface that can be used to know which users
19345 are logged in, know what kind of sessions they have open, suspend the
19346 system, inhibit system suspend, reboot the system, and other tasks.
19348 Elogind handles most system-level power events for a computer, for
19349 example suspending the system when a lid is closed, or shutting it down
19350 when the power button is pressed.
19352 The @var{config} keyword argument specifies the configuration for
19353 elogind, and should be the result of an @code{(elogind-configuration
19354 (@var{parameter} @var{value})...)} invocation. Available parameters and
19355 their default values are:
19358 @item kill-user-processes?
19360 @item kill-only-users
19362 @item kill-exclude-users
19364 @item inhibit-delay-max-seconds
19366 @item handle-power-key
19368 @item handle-suspend-key
19370 @item handle-hibernate-key
19372 @item handle-lid-switch
19374 @item handle-lid-switch-docked
19376 @item handle-lid-switch-external-power
19378 @item power-key-ignore-inhibited?
19380 @item suspend-key-ignore-inhibited?
19382 @item hibernate-key-ignore-inhibited?
19384 @item lid-switch-ignore-inhibited?
19386 @item holdoff-timeout-seconds
19390 @item idle-action-seconds
19392 @item runtime-directory-size-percent
19394 @item runtime-directory-size
19398 @item suspend-state
19399 @code{("mem" "standby" "freeze")}
19402 @item hibernate-state
19404 @item hibernate-mode
19405 @code{("platform" "shutdown")}
19406 @item hybrid-sleep-state
19408 @item hybrid-sleep-mode
19409 @code{("suspend" "platform" "shutdown")}
19413 @deffn {Scheme Procedure} accountsservice-service @
19414 [#:accountsservice @var{accountsservice}]
19415 Return a service that runs AccountsService, a system service that can
19416 list available accounts, change their passwords, and so on.
19417 AccountsService integrates with PolicyKit to enable unprivileged users
19418 to acquire the capability to modify their system configuration.
19419 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
19420 accountsservice web site} for more information.
19422 The @var{accountsservice} keyword argument is the @code{accountsservice}
19423 package to expose as a service.
19426 @deffn {Scheme Procedure} polkit-service @
19427 [#:polkit @var{polkit}]
19428 Return a service that runs the
19429 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
19430 management service}, which allows system administrators to grant access to
19431 privileged operations in a structured way. By querying the Polkit service, a
19432 privileged system component can know when it should grant additional
19433 capabilities to ordinary users. For example, an ordinary user can be granted
19434 the capability to suspend the system if the user is logged in locally.
19437 @defvr {Scheme Variable} polkit-wheel-service
19438 Service that adds the @code{wheel} group as admins to the Polkit
19439 service. This makes it so that users in the @code{wheel} group are queried
19440 for their own passwords when performing administrative actions instead of
19441 @code{root}'s, similar to the behaviour used by @code{sudo}.
19444 @defvr {Scheme Variable} upower-service-type
19445 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
19446 system-wide monitor for power consumption and battery levels, with the given
19447 configuration settings.
19449 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
19450 notably used by GNOME.
19453 @deftp {Data Type} upower-configuration
19454 Data type representation the configuration for UPower.
19458 @item @code{upower} (default: @var{upower})
19459 Package to use for @code{upower}.
19461 @item @code{watts-up-pro?} (default: @code{#f})
19462 Enable the Watts Up Pro device.
19464 @item @code{poll-batteries?} (default: @code{#t})
19465 Enable polling the kernel for battery level changes.
19467 @item @code{ignore-lid?} (default: @code{#f})
19468 Ignore the lid state, this can be useful if it's incorrect on a device.
19470 @item @code{use-percentage-for-policy?} (default: @code{#f})
19471 Whether battery percentage based policy should be used. The default is to use
19472 the time left, change to @code{#t} to use the percentage.
19474 @item @code{percentage-low} (default: @code{10})
19475 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19476 at which the battery is considered low.
19478 @item @code{percentage-critical} (default: @code{3})
19479 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19480 at which the battery is considered critical.
19482 @item @code{percentage-action} (default: @code{2})
19483 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19484 at which action will be taken.
19486 @item @code{time-low} (default: @code{1200})
19487 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19488 seconds at which the battery is considered low.
19490 @item @code{time-critical} (default: @code{300})
19491 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19492 seconds at which the battery is considered critical.
19494 @item @code{time-action} (default: @code{120})
19495 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19496 seconds at which action will be taken.
19498 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
19499 The action taken when @code{percentage-action} or @code{time-action} is
19500 reached (depending on the configuration of @code{use-percentage-for-policy?}).
19502 Possible values are:
19512 @code{'hybrid-sleep}.
19518 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
19519 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
19520 UDisks}, a @dfn{disk management} daemon that provides user interfaces
19521 with notifications and ways to mount/unmount disks. Programs that talk
19522 to UDisks include the @command{udisksctl} command, part of UDisks, and
19523 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
19524 it will only be able to use the file-system utilities installed in the
19525 system profile. For example if you want to be able to mount NTFS
19526 file-systems in read and write fashion, you'll need to have
19527 @code{ntfs-3g} installed system-wide.
19530 @deffn {Scheme Variable} colord-service-type
19531 This is the type of the service that runs @command{colord}, a system
19532 service with a D-Bus
19533 interface to manage the color profiles of input and output devices such as
19534 screens and scanners. It is notably used by the GNOME Color Manager graphical
19535 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
19536 site} for more information.
19539 @cindex scanner access
19540 @defvr {Scheme Variable} sane-service-type
19541 This service provides access to scanners @i{via}
19542 @uref{http://www.sane-project.org, SANE} by installing the necessary
19543 udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
19544 Services}) and relies by default on @code{sane-backends-minimal} package
19545 (see below) for hardware support.
19548 @defvr {Scheme Variable} sane-backends-minimal
19549 The default package which the @code{sane-service-type} installs. It
19550 supports many recent scanners.
19553 @defvr {Scheme Variable} sane-backends
19554 This package includes support for all scanners that
19555 @code{sane-backends-minimal} supports, plus older Hewlett-Packard
19556 scanners supported by @code{hplip} package. In order to use this on
19557 a system which relies on @code{%desktop-services}, you may use
19558 @code{modify-services} (@pxref{Service Reference,
19559 @code{modify-services}}) as illustrated below:
19562 (use-modules (gnu))
19563 (use-service-modules
19566 (use-package-modules
19570 (define %my-desktop-services
19571 ;; List of desktop services that supports a broader range of scanners.
19572 (modify-services %desktop-services
19573 (sane-service-type _ => sane-backends)))
19577 (services %my-desktop-services)
19581 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
19582 Return a configuration allowing an application to access GeoClue
19583 location data. @var{name} is the Desktop ID of the application, without
19584 the @code{.desktop} part. If @var{allowed?} is true, the application
19585 will have access to location information by default. The boolean
19586 @var{system?} value indicates whether an application is a system component
19587 or not. Finally @var{users} is a list of UIDs of all users for which
19588 this application is allowed location info access. An empty users list
19589 means that all users are allowed.
19592 @defvr {Scheme Variable} %standard-geoclue-applications
19593 The standard list of well-known GeoClue application configurations,
19594 granting authority to the GNOME date-and-time utility to ask for the
19595 current location in order to set the time zone, and allowing the
19596 IceCat and Epiphany web browsers to request location information.
19597 IceCat and Epiphany both query the user before allowing a web page to
19598 know the user's location.
19601 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
19602 [#:whitelist '()] @
19603 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
19604 [#:submit-data? #f]
19605 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
19606 [#:submission-nick "geoclue"] @
19607 [#:applications %standard-geoclue-applications]
19608 Return a service that runs the GeoClue location service. This service
19609 provides a D-Bus interface to allow applications to request access to a
19610 user's physical location, and optionally to add information to online
19611 location databases. See
19612 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
19613 web site} for more information.
19616 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
19617 [@w{#:auto-enable? #f}]
19618 Return a service that runs the @command{bluetoothd} daemon, which
19619 manages all the Bluetooth devices and provides a number of D-Bus
19620 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
19621 powered automatically at boot, which can be useful when using a
19622 bluetooth keyboard or mouse.
19624 Users need to be in the @code{lp} group to access the D-Bus service.
19627 @defvr {Scheme Variable} gnome-keyring-service-type
19628 This is the type of the service that adds the
19629 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
19630 value is a @code{gnome-keyring-configuration} object (see below).
19632 This service adds the @code{gnome-keyring} package to the system profile
19633 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
19634 a user's login keyring when they log in or setting its password with passwd.
19637 @deftp {Data Type} gnome-keyring-configuration
19638 Configuration record for the GNOME Keyring service.
19641 @item @code{keyring} (default: @code{gnome-keyring})
19642 The GNOME keyring package to use.
19644 @item @code{pam-services}
19645 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
19646 services to extend, where @var{service} is the name of an existing
19647 service to extend and @var{kind} is one of @code{login} or
19650 If @code{login} is given, it adds an optional
19651 @code{pam_gnome_keyring.so} to the auth block without arguments and to
19652 the session block with @code{auto_start}. If @code{passwd} is given, it
19653 adds an optional @code{pam_gnome_keyring.so} to the password block
19656 By default, this field contains ``gdm-password'' with the value @code{login}
19657 and ``passwd'' is with the value @code{passwd}.
19662 @node Sound Services
19663 @subsection Sound Services
19665 @cindex sound support
19667 @cindex PulseAudio, sound support
19669 The @code{(gnu services sound)} module provides a service to configure the
19670 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
19671 preferred ALSA output driver.
19673 @deffn {Scheme Variable} alsa-service-type
19674 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
19675 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
19676 configuration file. The value for this type is a @command{alsa-configuration}
19677 record as in this example:
19680 (service alsa-service-type)
19683 See below for details about @code{alsa-configuration}.
19686 @deftp {Data Type} alsa-configuration
19687 Data type representing the configuration for @code{alsa-service}.
19690 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19691 @code{alsa-plugins} package to use.
19693 @item @code{pulseaudio?} (default: @var{#t})
19694 Whether ALSA applications should transparently be made to use the
19695 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19697 Using PulseAudio allows you to run several sound-producing applications
19698 at the same time and to individual control them @i{via}
19699 @command{pavucontrol}, among other things.
19701 @item @code{extra-options} (default: @var{""})
19702 String to append to the @file{/etc/asound.conf} file.
19707 Individual users who want to override the system configuration of ALSA can do
19708 it with the @file{~/.asoundrc} file:
19711 # In guix, we have to specify the absolute path for plugins.
19713 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19716 # Routing ALSA to jack:
19717 # <http://jackaudio.org/faq/routing_alsa.html>.
19721 0 system:playback_1
19722 1 system:playback_2
19739 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19742 @deffn {Scheme Variable} pulseaudio-service-type
19743 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19744 sound server. It exists to allow system overrides of the default settings
19745 via @code{pulseaudio-configuration}, see below.
19748 This service overrides per-user configuration files. If you want
19749 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19750 have to unset the environment variables @env{PULSE_CONFIG} and
19751 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19755 This service on its own does not ensure, that the @code{pulseaudio} package
19756 exists on your machine. It merely adds configuration files for it, as
19757 detailed below. In the (admittedly unlikely) case, that you find yourself
19758 without a @code{pulseaudio} package, consider enabling it through the
19759 @code{alsa-service-type} above.
19763 @deftp {Data Type} pulseaudio-configuration
19764 Data type representing the configuration for @code{pulseaudio-service}.
19767 @item @code{client-conf} (default: @code{'()})
19768 List of settings to set in @file{client.conf}.
19769 Accepts a list of strings or a symbol-value pairs. A string will be
19770 inserted as-is with a newline added. A pair will be formatted as
19771 ``key = value'', again with a newline added.
19773 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19774 List of settings to set in @file{daemon.conf}, formatted just like
19777 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19778 Script file to use as @file{default.pa}.
19780 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19781 Script file to use as @file{system.pa}.
19785 @deffn {Scheme Variable} ladspa-service-type
19786 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19787 respect it, e.g. PulseAudio, can load LADSPA plugins.
19789 The following example will setup the service to enable modules from the
19790 @code{swh-plugins} package:
19793 (service ladspa-service-type
19794 (ladspa-configuration (plugins (list swh-plugins))))
19797 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19802 @node Database Services
19803 @subsection Database Services
19807 The @code{(gnu services databases)} module provides the following services.
19809 @subsubheading PostgreSQL
19811 The following example describes a PostgreSQL service with the default
19815 (service postgresql-service-type
19816 (postgresql-configuration
19817 (postgresql postgresql-10)))
19820 If the services fails to start, it may be due to an incompatible
19821 cluster already present in @var{data-directory}. Adjust it (or, if you
19822 don't need the cluster anymore, delete @var{data-directory}), then
19823 restart the service.
19825 Peer authentication is used by default and the @code{postgres} user
19826 account has no shell, which prevents the direct execution of @code{psql}
19827 commands as this user. To use @code{psql}, you can temporarily log in
19828 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19829 same name as one of the system users and then create the associated
19833 sudo -u postgres -s /bin/sh
19834 createuser --interactive
19835 createdb $MY_USER_LOGIN # Replace appropriately.
19838 @deftp {Data Type} postgresql-configuration
19839 Data type representing the configuration for the
19840 @code{postgresql-service-type}.
19843 @item @code{postgresql}
19844 PostgreSQL package to use for the service.
19846 @item @code{port} (default: @code{5432})
19847 Port on which PostgreSQL should listen.
19849 @item @code{locale} (default: @code{"en_US.utf8"})
19850 Locale to use as the default when creating the database cluster.
19852 @item @code{config-file} (default: @code{(postgresql-config-file)})
19853 The configuration file to use when running PostgreSQL@. The default
19854 behaviour uses the postgresql-config-file record with the default values
19857 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
19858 The directory where @command{pg_ctl} output will be written in a file
19859 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
19860 configuration errors for instance.
19862 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19863 Directory in which to store the data.
19865 @item @code{extension-packages} (default: @code{'()})
19866 @cindex postgresql extension-packages
19867 Additional extensions are loaded from packages listed in
19868 @var{extension-packages}. Extensions are available at runtime. For instance,
19869 to create a geographic database using the @code{postgis} extension, a user can
19870 configure the postgresql-service as in this example:
19874 (use-package-modules databases geo)
19878 ;; postgresql is required to run `psql' but postgis is not required for
19879 ;; proper operation.
19880 (packages (cons* postgresql %base-packages))
19883 (service postgresql-service-type
19884 (postgresql-configuration
19885 (postgresql postgresql-10)
19886 (extension-packages (list postgis))))
19890 Then the extension becomes visible and you can initialise an empty geographic
19891 database in this way:
19895 > create database postgistest;
19896 > \connect postgistest;
19897 > create extension postgis;
19898 > create extension postgis_topology;
19901 There is no need to add this field for contrib extensions such as hstore or
19902 dblink as they are already loadable by postgresql. This field is only
19903 required to add extensions provided by other packages.
19908 @deftp {Data Type} postgresql-config-file
19909 Data type representing the PostgreSQL configuration file. As shown in
19910 the following example, this can be used to customize the configuration
19911 of PostgreSQL@. Note that you can use any G-expression or filename in
19912 place of this record, if you already have a configuration file you'd
19913 like to use for example.
19916 (service postgresql-service-type
19917 (postgresql-configuration
19919 (postgresql-config-file
19920 (log-destination "stderr")
19922 (plain-file "pg_hba.conf"
19924 local all all trust
19925 host all all 127.0.0.1/32 md5
19926 host all all ::1/128 md5"))
19928 '(("session_preload_libraries" "auto_explain")
19929 ("random_page_cost" 2)
19930 ("auto_explain.log_min_duration" "100 ms")
19931 ("work_mem" "500 MB")
19932 ("logging_collector" #t)
19933 ("log_directory" "/var/log/postgresql")))))))
19937 @item @code{log-destination} (default: @code{"syslog"})
19938 The logging method to use for PostgreSQL@. Multiple values are accepted,
19939 separated by commas.
19941 @item @code{hba-file} (default: @code{%default-postgres-hba})
19942 Filename or G-expression for the host-based authentication
19945 @item @code{ident-file} (default: @code{%default-postgres-ident})
19946 Filename or G-expression for the user name mapping configuration.
19948 @item @code{socket-directory} (default: @code{#false})
19949 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
19950 is to listen for connections from client applications. If set to
19951 @code{""} PostgreSQL does not listen on any Unix-domain sockets, in
19952 which case only TCP/IP sockets can be used to connect to the server.
19954 By default, the @code{#false} value means the PostgreSQL default value
19955 will be used, which is currently @samp{/tmp}.
19957 @item @code{extra-config} (default: @code{'()})
19958 List of additional keys and values to include in the PostgreSQL config
19959 file. Each entry in the list should be a list where the first element
19960 is the key, and the remaining elements are the values.
19962 The values can be numbers, booleans or strings and will be mapped to
19963 PostgreSQL parameters types @code{Boolean}, @code{String},
19964 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
19965 @uref{https://www.postgresql.org/docs/current/config-setting.html,
19971 @deffn {Scheme Variable} postgresql-role-service-type
19972 This service allows to create PostgreSQL roles and databases after
19973 PostgreSQL service start. Here is an example of its use.
19976 (service postgresql-role-service-type
19977 (postgresql-role-configuration
19979 (list (postgresql-role
19981 (create-database? #t))))))
19984 This service can be extended with extra roles, as in this
19988 (service-extension postgresql-role-service-type
19989 (const (postgresql-role
19991 (create-database? #t))))
19995 @deftp {Data Type} postgresql-role
19996 PostgreSQL manages database access permissions using the concept of
19997 roles. A role can be thought of as either a database user, or a group
19998 of database users, depending on how the role is set up. Roles can own
19999 database objects (for example, tables) and can assign privileges on
20000 those objects to other roles to control who has access to which objects.
20006 @item @code{permissions} (default: @code{'(createdb login)})
20007 The role permissions list. Supported permissions are @code{bypassrls},
20008 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
20011 @item @code{create-database?} (default: @code{#f})
20012 Whether to create a database with the same name as the role.
20017 @deftp {Data Type} postgresql-role-configuration
20018 Data type representing the configuration of
20019 @var{postgresql-role-service-type}.
20022 @item @code{host} (default: @code{"/var/run/postgresql"})
20023 The PostgreSQL host to connect to.
20025 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
20026 File name of the log file.
20028 @item @code{roles} (default: @code{'()})
20029 The initial PostgreSQL roles to create.
20033 @subsubheading MariaDB/MySQL
20035 @defvr {Scheme Variable} mysql-service-type
20036 This is the service type for a MySQL or MariaDB database server. Its value
20037 is a @code{mysql-configuration} object that specifies which package to use,
20038 as well as various settings for the @command{mysqld} daemon.
20041 @deftp {Data Type} mysql-configuration
20042 Data type representing the configuration of @var{mysql-service-type}.
20045 @item @code{mysql} (default: @var{mariadb})
20046 Package object of the MySQL database server, can be either @var{mariadb}
20049 For MySQL, a temporary root password will be displayed at activation time.
20050 For MariaDB, the root password is empty.
20052 @item @code{bind-address} (default: @code{"127.0.0.1"})
20053 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
20054 to bind to all available network interfaces.
20056 @item @code{port} (default: @code{3306})
20057 TCP port on which the database server listens for incoming connections.
20059 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
20060 Socket file to use for local (non-network) connections.
20062 @item @code{extra-content} (default: @code{""})
20063 Additional settings for the @file{my.cnf} configuration file.
20065 @item @code{extra-environment} (default: @code{#~'()})
20066 List of environment variables passed to the @command{mysqld} process.
20068 @item @code{auto-upgrade?} (default: @code{#t})
20069 Whether to automatically run @command{mysql_upgrade} after starting the
20070 service. This is necessary to upgrade the @dfn{system schema} after
20071 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
20072 be disabled if you would rather do that manually.
20077 @subsubheading Memcached
20079 @defvr {Scheme Variable} memcached-service-type
20080 This is the service type for the @uref{https://memcached.org/,
20081 Memcached} service, which provides a distributed in memory cache. The
20082 value for the service type is a @code{memcached-configuration} object.
20086 (service memcached-service-type)
20089 @deftp {Data Type} memcached-configuration
20090 Data type representing the configuration of memcached.
20093 @item @code{memcached} (default: @code{memcached})
20094 The Memcached package to use.
20096 @item @code{interfaces} (default: @code{'("0.0.0.0")})
20097 Network interfaces on which to listen.
20099 @item @code{tcp-port} (default: @code{11211})
20100 Port on which to accept connections.
20102 @item @code{udp-port} (default: @code{11211})
20103 Port on which to accept UDP connections on, a value of 0 will disable
20104 listening on a UDP socket.
20106 @item @code{additional-options} (default: @code{'()})
20107 Additional command line options to pass to @code{memcached}.
20111 @subsubheading Redis
20113 @defvr {Scheme Variable} redis-service-type
20114 This is the service type for the @uref{https://redis.io/, Redis}
20115 key/value store, whose value is a @code{redis-configuration} object.
20118 @deftp {Data Type} redis-configuration
20119 Data type representing the configuration of redis.
20122 @item @code{redis} (default: @code{redis})
20123 The Redis package to use.
20125 @item @code{bind} (default: @code{"127.0.0.1"})
20126 Network interface on which to listen.
20128 @item @code{port} (default: @code{6379})
20129 Port on which to accept connections on, a value of 0 will disable
20130 listening on a TCP socket.
20132 @item @code{working-directory} (default: @code{"/var/lib/redis"})
20133 Directory in which to store the database and related files.
20137 @node Mail Services
20138 @subsection Mail Services
20142 The @code{(gnu services mail)} module provides Guix service definitions
20143 for email services: IMAP, POP3, and LMTP servers, as well as mail
20144 transport agents (MTAs). Lots of acronyms! These services are detailed
20145 in the subsections below.
20147 @subsubheading Dovecot Service
20149 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
20150 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
20153 By default, Dovecot does not need much configuration; the default
20154 configuration object created by @code{(dovecot-configuration)} will
20155 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
20156 certificate will be generated for TLS-protected connections, though
20157 Dovecot will also listen on cleartext ports by default. There are a
20158 number of options, though, which mail administrators might need to change,
20159 and as is the case with other services, Guix allows the system
20160 administrator to specify these parameters via a uniform Scheme interface.
20162 For example, to specify that mail is located at @code{maildir~/.mail},
20163 one would instantiate the Dovecot service like this:
20166 (dovecot-service #:config
20167 (dovecot-configuration
20168 (mail-location "maildir:~/.mail")))
20171 The available configuration parameters follow. Each parameter
20172 definition is preceded by its type; for example, @samp{string-list foo}
20173 indicates that the @code{foo} parameter should be specified as a list of
20174 strings. There is also a way to specify the configuration as a string,
20175 if you have an old @code{dovecot.conf} file that you want to port over
20176 from some other system; see the end for more details.
20178 @c The following documentation was initially generated by
20179 @c (generate-documentation) in (gnu services mail). Manually maintained
20180 @c documentation is better, so we shouldn't hesitate to edit below as
20181 @c needed. However if the change you want to make to this documentation
20182 @c can be done in an automated way, it's probably easier to change
20183 @c (generate-documentation) than to make it below and have to deal with
20184 @c the churn as dovecot updates.
20186 Available @code{dovecot-configuration} fields are:
20188 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
20189 The dovecot package.
20192 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
20193 A list of IPs or hosts where to listen for connections. @samp{*}
20194 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
20195 interfaces. If you want to specify non-default ports or anything more
20196 complex, customize the address and port fields of the
20197 @samp{inet-listener} of the specific services you are interested in.
20200 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
20201 List of protocols we want to serve. Available protocols include
20202 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
20204 Available @code{protocol-configuration} fields are:
20206 @deftypevr {@code{protocol-configuration} parameter} string name
20207 The name of the protocol.
20210 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
20211 UNIX socket path to the master authentication server to find users.
20212 This is used by imap (for shared users) and lda.
20213 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20216 @deftypevr {@code{protocol-configuration} parameter} boolean imap-metadata?
20217 Whether to enable the @code{IMAP METADATA} extension as defined in
20218 @uref{https://tools.ietf.org/html/rfc5464,RFC@tie{}5464}, which provides
20219 a means for clients to set and retrieve per-mailbox, per-user metadata
20220 and annotations over IMAP.
20222 If this is @samp{#t}, you must also specify a dictionary @i{via} the
20223 @code{mail-attribute-dict} setting.
20225 Defaults to @samp{#f}.
20229 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list managesieve-notify-capabilities
20230 Which NOTIFY capabilities to report to clients that first connect to
20231 the ManageSieve service, before authentication. These may differ from the
20232 capabilities offered to authenticated users. If this field is left empty,
20233 report what the Sieve interpreter supports by default.
20235 Defaults to @samp{()}.
20238 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list managesieve-sieve-capability
20239 Which SIEVE capabilities to report to clients that first connect to
20240 the ManageSieve service, before authentication. These may differ from the
20241 capabilities offered to authenticated users. If this field is left empty,
20242 report what the Sieve interpreter supports by default.
20244 Defaults to @samp{()}.
20248 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
20249 Space separated list of plugins to load.
20252 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
20253 Maximum number of IMAP connections allowed for a user from each IP
20254 address. NOTE: The username is compared case-sensitively.
20255 Defaults to @samp{10}.
20260 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
20261 List of services to enable. Available services include @samp{imap},
20262 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
20265 Available @code{service-configuration} fields are:
20267 @deftypevr {@code{service-configuration} parameter} string kind
20268 The service kind. Valid values include @code{director},
20269 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
20270 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
20271 @code{tcpwrap}, @code{quota-warning}, or anything else.
20274 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
20275 Listeners for the service. A listener is either a
20276 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
20277 an @code{inet-listener-configuration}.
20278 Defaults to @samp{()}.
20280 Available @code{unix-listener-configuration} fields are:
20282 @deftypevr {@code{unix-listener-configuration} parameter} string path
20283 Path to the file, relative to @code{base-dir} field. This is also used as
20287 @deftypevr {@code{unix-listener-configuration} parameter} string mode
20288 The access mode for the socket.
20289 Defaults to @samp{"0600"}.
20292 @deftypevr {@code{unix-listener-configuration} parameter} string user
20293 The user to own the socket.
20294 Defaults to @samp{""}.
20297 @deftypevr {@code{unix-listener-configuration} parameter} string group
20298 The group to own the socket.
20299 Defaults to @samp{""}.
20303 Available @code{fifo-listener-configuration} fields are:
20305 @deftypevr {@code{fifo-listener-configuration} parameter} string path
20306 Path to the file, relative to @code{base-dir} field. This is also used as
20310 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
20311 The access mode for the socket.
20312 Defaults to @samp{"0600"}.
20315 @deftypevr {@code{fifo-listener-configuration} parameter} string user
20316 The user to own the socket.
20317 Defaults to @samp{""}.
20320 @deftypevr {@code{fifo-listener-configuration} parameter} string group
20321 The group to own the socket.
20322 Defaults to @samp{""}.
20326 Available @code{inet-listener-configuration} fields are:
20328 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
20329 The protocol to listen for.
20332 @deftypevr {@code{inet-listener-configuration} parameter} string address
20333 The address on which to listen, or empty for all addresses.
20334 Defaults to @samp{""}.
20337 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
20338 The port on which to listen.
20341 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
20342 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
20344 Defaults to @samp{#t}.
20349 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
20350 Maximum number of simultaneous client connections per process. Once
20351 this number of connections is received, the next incoming connection
20352 will prompt Dovecot to spawn another process. If set to 0,
20353 @code{default-client-limit} is used instead.
20355 Defaults to @samp{0}.
20359 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
20360 Number of connections to handle before starting a new process.
20361 Typically the only useful values are 0 (unlimited) or 1. 1 is more
20362 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
20363 Defaults to @samp{1}.
20367 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
20368 Maximum number of processes that can exist for this service. If set to
20369 0, @code{default-process-limit} is used instead.
20371 Defaults to @samp{0}.
20375 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
20376 Number of processes to always keep waiting for more connections.
20377 Defaults to @samp{0}.
20380 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
20381 If you set @samp{service-count 0}, you probably need to grow
20383 Defaults to @samp{256000000}.
20388 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
20389 Dict configuration, as created by the @code{dict-configuration}
20392 Available @code{dict-configuration} fields are:
20394 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
20395 A list of key-value pairs that this dict should hold.
20396 Defaults to @samp{()}.
20401 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
20402 A list of passdb configurations, each one created by the
20403 @code{passdb-configuration} constructor.
20405 Available @code{passdb-configuration} fields are:
20407 @deftypevr {@code{passdb-configuration} parameter} string driver
20408 The driver that the passdb should use. Valid values include
20409 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
20411 Defaults to @samp{"pam"}.
20414 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
20415 Space separated list of arguments to the passdb driver.
20416 Defaults to @samp{""}.
20421 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
20422 List of userdb configurations, each one created by the
20423 @code{userdb-configuration} constructor.
20425 Available @code{userdb-configuration} fields are:
20427 @deftypevr {@code{userdb-configuration} parameter} string driver
20428 The driver that the userdb should use. Valid values include
20429 @samp{passwd} and @samp{static}.
20430 Defaults to @samp{"passwd"}.
20433 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
20434 Space separated list of arguments to the userdb driver.
20435 Defaults to @samp{""}.
20438 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
20439 Override fields from passwd.
20440 Defaults to @samp{()}.
20445 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
20446 Plug-in configuration, created by the @code{plugin-configuration}
20450 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
20451 List of namespaces. Each item in the list is created by the
20452 @code{namespace-configuration} constructor.
20454 Available @code{namespace-configuration} fields are:
20456 @deftypevr {@code{namespace-configuration} parameter} string name
20457 Name for this namespace.
20460 @deftypevr {@code{namespace-configuration} parameter} string type
20461 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
20462 Defaults to @samp{"private"}.
20465 @deftypevr {@code{namespace-configuration} parameter} string separator
20466 Hierarchy separator to use. You should use the same separator for
20467 all namespaces or some clients get confused. @samp{/} is usually a good
20468 one. The default however depends on the underlying mail storage
20470 Defaults to @samp{""}.
20473 @deftypevr {@code{namespace-configuration} parameter} string prefix
20474 Prefix required to access this namespace. This needs to be
20475 different for all namespaces. For example @samp{Public/}.
20476 Defaults to @samp{""}.
20479 @deftypevr {@code{namespace-configuration} parameter} string location
20480 Physical location of the mailbox. This is in the same format as
20481 mail_location, which is also the default for it.
20482 Defaults to @samp{""}.
20485 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
20486 There can be only one INBOX, and this setting defines which
20488 Defaults to @samp{#f}.
20491 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
20492 If namespace is hidden, it's not advertised to clients via NAMESPACE
20493 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
20494 useful when converting from another server with different namespaces
20495 which you want to deprecate but still keep working. For example you can
20496 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
20498 Defaults to @samp{#f}.
20501 @deftypevr {@code{namespace-configuration} parameter} boolean list?
20502 Show the mailboxes under this namespace with the LIST command. This
20503 makes the namespace visible for clients that do not support the NAMESPACE
20504 extension. The special @code{children} value lists child mailboxes, but
20505 hides the namespace prefix.
20506 Defaults to @samp{#t}.
20509 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
20510 Namespace handles its own subscriptions. If set to @code{#f}, the
20511 parent namespace handles them. The empty prefix should always have this
20513 Defaults to @samp{#t}.
20516 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
20517 List of predefined mailboxes in this namespace.
20518 Defaults to @samp{()}.
20520 Available @code{mailbox-configuration} fields are:
20522 @deftypevr {@code{mailbox-configuration} parameter} string name
20523 Name for this mailbox.
20526 @deftypevr {@code{mailbox-configuration} parameter} string auto
20527 @samp{create} will automatically create this mailbox.
20528 @samp{subscribe} will both create and subscribe to the mailbox.
20529 Defaults to @samp{"no"}.
20532 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
20533 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
20534 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
20535 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
20536 Defaults to @samp{()}.
20543 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
20544 Base directory where to store runtime data.
20545 Defaults to @samp{"/var/run/dovecot/"}.
20548 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
20549 Greeting message for clients.
20550 Defaults to @samp{"Dovecot ready."}.
20553 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
20554 List of trusted network ranges. Connections from these IPs are
20555 allowed to override their IP addresses and ports (for logging and for
20556 authentication checks). @samp{disable-plaintext-auth} is also ignored
20557 for these networks. Typically you would specify your IMAP proxy servers
20559 Defaults to @samp{()}.
20562 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
20563 List of login access check sockets (e.g.@: tcpwrap).
20564 Defaults to @samp{()}.
20567 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
20568 Show more verbose process titles (in ps). Currently shows user name
20569 and IP address. Useful for seeing who is actually using the IMAP
20570 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
20572 Defaults to @samp{#f}.
20575 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
20576 Should all processes be killed when Dovecot master process shuts down.
20577 Setting this to @code{#f} means that Dovecot can be upgraded without
20578 forcing existing client connections to close (although that could also
20579 be a problem if the upgrade is e.g.@: due to a security fix).
20580 Defaults to @samp{#t}.
20583 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
20584 If non-zero, run mail commands via this many connections to doveadm
20585 server, instead of running them directly in the same process.
20586 Defaults to @samp{0}.
20589 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
20590 UNIX socket or host:port used for connecting to doveadm server.
20591 Defaults to @samp{"doveadm-server"}.
20594 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
20595 List of environment variables that are preserved on Dovecot startup
20596 and passed down to all of its child processes. You can also give
20597 key=value pairs to always set specific settings.
20600 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
20601 Disable LOGIN command and all other plaintext authentications unless
20602 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
20603 matches the local IP (i.e.@: you're connecting from the same computer),
20604 the connection is considered secure and plaintext authentication is
20605 allowed. See also ssl=required setting.
20606 Defaults to @samp{#t}.
20609 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
20610 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
20611 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
20612 for caching to be used.
20613 Defaults to @samp{0}.
20616 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
20617 Time to live for cached data. After TTL expires the cached record
20618 is no longer used, *except* if the main database lookup returns internal
20619 failure. We also try to handle password changes automatically: If
20620 user's previous authentication was successful, but this one wasn't, the
20621 cache isn't used. For now this works only with plaintext
20623 Defaults to @samp{"1 hour"}.
20626 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
20627 TTL for negative hits (user not found, password mismatch).
20628 0 disables caching them completely.
20629 Defaults to @samp{"1 hour"}.
20632 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
20633 List of realms for SASL authentication mechanisms that need them.
20634 You can leave it empty if you don't want to support multiple realms.
20635 Many clients simply use the first one listed here, so keep the default
20637 Defaults to @samp{()}.
20640 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
20641 Default realm/domain to use if none was specified. This is used for
20642 both SASL realms and appending @@domain to username in plaintext
20644 Defaults to @samp{""}.
20647 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
20648 List of allowed characters in username. If the user-given username
20649 contains a character not listed in here, the login automatically fails.
20650 This is just an extra check to make sure user can't exploit any
20651 potential quote escaping vulnerabilities with SQL/LDAP databases. If
20652 you want to allow all characters, set this value to empty.
20653 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
20656 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
20657 Username character translations before it's looked up from
20658 databases. The value contains series of from -> to characters. For
20659 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
20660 translated to @samp{@@}.
20661 Defaults to @samp{""}.
20664 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
20665 Username formatting before it's looked up from databases. You can
20666 use the standard variables here, e.g.@: %Lu would lowercase the username,
20667 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
20668 change the @samp{@@} into @samp{-AT-}. This translation is done after
20669 @samp{auth-username-translation} changes.
20670 Defaults to @samp{"%Lu"}.
20673 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
20674 If you want to allow master users to log in by specifying the master
20675 username within the normal username string (i.e.@: not using SASL
20676 mechanism's support for it), you can specify the separator character
20677 here. The format is then <username><separator><master username>.
20678 UW-IMAP uses @samp{*} as the separator, so that could be a good
20680 Defaults to @samp{""}.
20683 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
20684 Username to use for users logging in with ANONYMOUS SASL
20686 Defaults to @samp{"anonymous"}.
20689 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
20690 Maximum number of dovecot-auth worker processes. They're used to
20691 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
20692 They're automatically created and destroyed as needed.
20693 Defaults to @samp{30}.
20696 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
20697 Host name to use in GSSAPI principal names. The default is to use
20698 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
20699 allow all keytab entries.
20700 Defaults to @samp{""}.
20703 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
20704 Kerberos keytab to use for the GSSAPI mechanism. Will use the
20705 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
20706 need to change the auth service to run as root to be able to read this
20708 Defaults to @samp{""}.
20711 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
20712 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
20713 and @samp{ntlm-auth} helper.
20714 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
20715 Defaults to @samp{#f}.
20718 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
20719 Path for Samba's @samp{ntlm-auth} helper binary.
20720 Defaults to @samp{"/usr/bin/ntlm_auth"}.
20723 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
20724 Time to delay before replying to failed authentications.
20725 Defaults to @samp{"2 secs"}.
20728 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
20729 Require a valid SSL client certificate or the authentication
20731 Defaults to @samp{#f}.
20734 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
20735 Take the username from client's SSL certificate, using
20736 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
20738 Defaults to @samp{#f}.
20741 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
20742 List of wanted authentication mechanisms. Supported mechanisms are:
20743 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
20744 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
20745 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
20746 @samp{disable-plaintext-auth} setting.
20749 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
20750 List of IPs or hostnames to all director servers, including ourself.
20751 Ports can be specified as ip:port. The default port is the same as what
20752 director service's @samp{inet-listener} is using.
20753 Defaults to @samp{()}.
20756 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
20757 List of IPs or hostnames to all backend mail servers. Ranges are
20758 allowed too, like 10.0.0.10-10.0.0.30.
20759 Defaults to @samp{()}.
20762 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
20763 How long to redirect users to a specific server after it no longer
20764 has any connections.
20765 Defaults to @samp{"15 min"}.
20768 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
20769 How the username is translated before being hashed. Useful values
20770 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
20771 are shared within domain.
20772 Defaults to @samp{"%Lu"}.
20775 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20776 Log file to use for error messages. @samp{syslog} logs to syslog,
20777 @samp{/dev/stderr} logs to stderr.
20778 Defaults to @samp{"syslog"}.
20781 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20782 Log file to use for informational messages. Defaults to
20784 Defaults to @samp{""}.
20787 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20788 Log file to use for debug messages. Defaults to
20789 @samp{info-log-path}.
20790 Defaults to @samp{""}.
20793 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20794 Syslog facility to use if you're logging to syslog. Usually if you
20795 don't want to use @samp{mail}, you'll use local0..local7. Also other
20796 standard facilities are supported.
20797 Defaults to @samp{"mail"}.
20800 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20801 Log unsuccessful authentication attempts and the reasons why they
20803 Defaults to @samp{#f}.
20806 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20807 In case of password mismatches, log the attempted password. Valid
20808 values are no, plain and sha1. sha1 can be useful for detecting brute
20809 force password attempts vs. user simply trying the same password over
20810 and over again. You can also truncate the value to n chars by appending
20811 ":n" (e.g.@: sha1:6).
20812 Defaults to @samp{"no"}.
20815 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20816 Even more verbose logging for debugging purposes. Shows for example
20818 Defaults to @samp{#f}.
20821 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20822 In case of password mismatches, log the passwords and used scheme so
20823 the problem can be debugged. Enabling this also enables
20825 Defaults to @samp{#f}.
20828 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20829 Enable mail process debugging. This can help you figure out why
20830 Dovecot isn't finding your mails.
20831 Defaults to @samp{#f}.
20834 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20835 Show protocol level SSL errors.
20836 Defaults to @samp{#f}.
20839 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20840 Prefix for each line written to log file. % codes are in
20841 strftime(3) format.
20842 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20845 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20846 List of elements we want to log. The elements which have a
20847 non-empty variable value are joined together to form a comma-separated
20851 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20852 Login log format. %s contains @samp{login-log-format-elements}
20853 string, %$ contains the data we want to log.
20854 Defaults to @samp{"%$: %s"}.
20857 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20858 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20859 of possible variables you can use.
20860 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20863 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20864 Format to use for logging mail deliveries. You can use variables:
20867 Delivery status message (e.g.@: @samp{saved to INBOX})
20879 Defaults to @samp{"msgid=%m: %$"}.
20882 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20883 Location for users' mailboxes. The default is empty, which means
20884 that Dovecot tries to find the mailboxes automatically. This won't work
20885 if the user doesn't yet have any mail, so you should explicitly tell
20886 Dovecot the full location.
20888 If you're using mbox, giving a path to the INBOX
20889 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20890 where the other mailboxes are kept. This is called the @emph{root mail
20891 directory}, and it must be the first path given in the
20892 @samp{mail-location} setting.
20894 There are a few special variables you can use, e.g.:
20900 user part in user@@domain, same as %u if there's no domain
20902 domain part in user@@domain, empty if there's no domain
20907 See doc/wiki/Variables.txt for full list. Some examples:
20909 @item maildir:~/Maildir
20910 @item mbox:~/mail:INBOX=/var/mail/%u
20911 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20913 Defaults to @samp{""}.
20916 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20917 System user and group used to access mails. If you use multiple,
20918 userdb can override these by returning uid or gid fields. You can use
20919 either numbers or names. <doc/wiki/UserIds.txt>.
20920 Defaults to @samp{""}.
20923 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20925 Defaults to @samp{""}.
20928 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20929 Group to enable temporarily for privileged operations. Currently
20930 this is used only with INBOX when either its initial creation or
20931 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20933 Defaults to @samp{""}.
20936 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20937 Grant access to these supplementary groups for mail processes.
20938 Typically these are used to set up access to shared mailboxes. Note
20939 that it may be dangerous to set these if users can create symlinks
20940 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20941 could allow a user to delete others' mailboxes, or @code{ln -s
20942 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20946 @deftypevr {@code{dovecot-configuration} parameter} string mail-attribute-dict
20947 The location of a dictionary used to store @code{IMAP METADATA}
20948 as defined by @uref{https://tools.ietf.org/html/rfc5464, RFC@tie{}5464}.
20950 The IMAP METADATA commands are available only if the ``imap''
20951 protocol configuration's @code{imap-metadata?} field is @samp{#t}.
20953 Defaults to @samp{""}.
20957 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20958 Allow full file system access to clients. There's no access checks
20959 other than what the operating system does for the active UID/GID@. It
20960 works with both maildir and mboxes, allowing you to prefix mailboxes
20961 names with e.g.@: @file{/path/} or @file{~user/}.
20962 Defaults to @samp{#f}.
20965 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20966 Don't use @code{mmap()} at all. This is required if you store indexes to
20967 shared file systems (NFS or clustered file system).
20968 Defaults to @samp{#f}.
20971 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20972 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20973 supports @samp{O_EXCL} since version 3, so this should be safe to use
20974 nowadays by default.
20975 Defaults to @samp{#t}.
20978 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20979 When to use fsync() or fdatasync() calls:
20982 Whenever necessary to avoid losing important data
20984 Useful with e.g.@: NFS when @code{write()}s are delayed
20986 Never use it (best performance, but crashes can lose data).
20988 Defaults to @samp{"optimized"}.
20991 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20992 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
20993 NFS caches whenever needed. If you're using only a single mail server
20995 Defaults to @samp{#f}.
20998 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20999 Mail index files also exist in NFS@. Setting this to yes requires
21000 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
21001 Defaults to @samp{#f}.
21004 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
21005 Locking method for index files. Alternatives are fcntl, flock and
21006 dotlock. Dotlocking uses some tricks which may create more disk I/O
21007 than other locking methods. NFS users: flock doesn't work, remember to
21008 change @samp{mmap-disable}.
21009 Defaults to @samp{"fcntl"}.
21012 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
21013 Directory in which LDA/LMTP temporarily stores incoming mails >128
21015 Defaults to @samp{"/tmp"}.
21018 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
21019 Valid UID range for users. This is mostly to make sure that users can't
21020 log in as daemons or other system users. Note that denying root logins is
21021 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
21023 Defaults to @samp{500}.
21026 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
21028 Defaults to @samp{0}.
21031 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
21032 Valid GID range for users. Users having non-valid GID as primary group ID
21033 aren't allowed to log in. If user belongs to supplementary groups with
21034 non-valid GIDs, those groups are not set.
21035 Defaults to @samp{1}.
21038 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
21040 Defaults to @samp{0}.
21043 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
21044 Maximum allowed length for mail keyword name. It's only forced when
21045 trying to create new keywords.
21046 Defaults to @samp{50}.
21049 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
21050 List of directories under which chrooting is allowed for mail
21051 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
21052 too). This setting doesn't affect @samp{login-chroot}
21053 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
21054 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
21055 which local users can modify, that may lead to root exploit. Usually
21056 this should be done only if you don't allow shell access for users.
21057 <doc/wiki/Chrooting.txt>.
21058 Defaults to @samp{()}.
21061 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
21062 Default chroot directory for mail processes. This can be overridden
21063 for specific users in user database by giving @samp{/./} in user's home
21064 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
21065 there is no real need to do chrooting, Dovecot doesn't allow users to
21066 access files outside their mail directory anyway. If your home
21067 directories are prefixed with the chroot directory, append @samp{/.} to
21068 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
21069 Defaults to @samp{""}.
21072 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
21073 UNIX socket path to master authentication server to find users.
21074 This is used by imap (for shared users) and lda.
21075 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
21078 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
21079 Directory where to look up mail plugins.
21080 Defaults to @samp{"/usr/lib/dovecot"}.
21083 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
21084 List of plugins to load for all services. Plugins specific to IMAP,
21085 LDA, etc.@: are added to this list in their own .conf files.
21086 Defaults to @samp{()}.
21089 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
21090 The minimum number of mails in a mailbox before updates are done to
21091 cache file. This allows optimizing Dovecot's behavior to do less disk
21092 writes at the cost of more disk reads.
21093 Defaults to @samp{0}.
21096 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
21097 When IDLE command is running, mailbox is checked once in a while to
21098 see if there are any new mails or other changes. This setting defines
21099 the minimum time to wait between those checks. Dovecot can also use
21100 dnotify, inotify and kqueue to find out immediately when changes
21102 Defaults to @samp{"30 secs"}.
21105 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
21106 Save mails with CR+LF instead of plain LF@. This makes sending those
21107 mails take less CPU, especially with sendfile() syscall with Linux and
21108 FreeBSD@. But it also creates a bit more disk I/O which may just make it
21109 slower. Also note that if other software reads the mboxes/maildirs,
21110 they may handle the extra CRs wrong and cause problems.
21111 Defaults to @samp{#f}.
21114 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
21115 By default LIST command returns all entries in maildir beginning
21116 with a dot. Enabling this option makes Dovecot return only entries
21117 which are directories. This is done by stat()ing each entry, so it
21118 causes more disk I/O.
21119 (For systems setting struct @samp{dirent->d_type} this check is free
21120 and it's done always regardless of this setting).
21121 Defaults to @samp{#f}.
21124 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
21125 When copying a message, do it with hard links whenever possible.
21126 This makes the performance much better, and it's unlikely to have any
21128 Defaults to @samp{#t}.
21131 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
21132 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
21133 directory only when its mtime changes unexpectedly or when we can't find
21134 the mail otherwise.
21135 Defaults to @samp{#f}.
21138 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
21139 Which locking methods to use for locking mbox. There are four
21144 Create <mailbox>.lock file. This is the oldest and most NFS-safe
21145 solution. If you want to use /var/mail/ like directory, the users will
21146 need write access to that directory.
21148 Same as dotlock, but if it fails because of permissions or because there
21149 isn't enough disk space, just skip it.
21151 Use this if possible. Works with NFS too if lockd is used.
21153 May not exist in all systems. Doesn't work with NFS.
21155 May not exist in all systems. Doesn't work with NFS.
21158 You can use multiple locking methods; if you do the order they're declared
21159 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
21160 locking methods as well. Some operating systems don't allow using some of
21161 them simultaneously.
21164 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
21168 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
21169 Maximum time to wait for lock (all of them) before aborting.
21170 Defaults to @samp{"5 mins"}.
21173 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
21174 If dotlock exists but the mailbox isn't modified in any way,
21175 override the lock file after this much time.
21176 Defaults to @samp{"2 mins"}.
21179 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
21180 When mbox changes unexpectedly we have to fully read it to find out
21181 what changed. If the mbox is large this can take a long time. Since
21182 the change is usually just a newly appended mail, it'd be faster to
21183 simply read the new mails. If this setting is enabled, Dovecot does
21184 this but still safely fallbacks to re-reading the whole mbox file
21185 whenever something in mbox isn't how it's expected to be. The only real
21186 downside to this setting is that if some other MUA changes message
21187 flags, Dovecot doesn't notice it immediately. Note that a full sync is
21188 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
21189 Defaults to @samp{#t}.
21192 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
21193 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
21194 EXAMINE, EXPUNGE or CHECK commands. If this is set,
21195 @samp{mbox-dirty-syncs} is ignored.
21196 Defaults to @samp{#f}.
21199 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
21200 Delay writing mbox headers until doing a full write sync (EXPUNGE
21201 and CHECK commands and when closing the mailbox). This is especially
21202 useful for POP3 where clients often delete all mails. The downside is
21203 that our changes aren't immediately visible to other MUAs.
21204 Defaults to @samp{#t}.
21207 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
21208 If mbox size is smaller than this (e.g.@: 100k), don't write index
21209 files. If an index file already exists it's still read, just not
21211 Defaults to @samp{0}.
21214 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
21215 Maximum dbox file size until it's rotated.
21216 Defaults to @samp{10000000}.
21219 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
21220 Maximum dbox file age until it's rotated. Typically in days. Day
21221 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
21223 Defaults to @samp{"1d"}.
21226 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
21227 When creating new mdbox files, immediately preallocate their size to
21228 @samp{mdbox-rotate-size}. This setting currently works only in Linux
21229 with some file systems (ext4, xfs).
21230 Defaults to @samp{#f}.
21233 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
21234 sdbox and mdbox support saving mail attachments to external files,
21235 which also allows single instance storage for them. Other backends
21236 don't support this for now.
21238 WARNING: This feature hasn't been tested much yet. Use at your own risk.
21240 Directory root where to store mail attachments. Disabled, if empty.
21241 Defaults to @samp{""}.
21244 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
21245 Attachments smaller than this aren't saved externally. It's also
21246 possible to write a plugin to disable saving specific attachments
21248 Defaults to @samp{128000}.
21251 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
21252 File system backend to use for saving attachments:
21255 No SiS done by Dovecot (but this might help FS's own deduplication)
21257 SiS with immediate byte-by-byte comparison during saving
21258 @item sis-queue posix
21259 SiS with delayed comparison and deduplication.
21261 Defaults to @samp{"sis posix"}.
21264 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
21265 Hash format to use in attachment filenames. You can add any text and
21266 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
21267 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
21268 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
21269 Defaults to @samp{"%@{sha1@}"}.
21272 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
21274 Defaults to @samp{100}.
21277 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
21279 Defaults to @samp{1000}.
21282 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
21283 Default VSZ (virtual memory size) limit for service processes.
21284 This is mainly intended to catch and kill processes that leak memory
21285 before they eat up everything.
21286 Defaults to @samp{256000000}.
21289 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
21290 Login user is internally used by login processes. This is the most
21291 untrusted user in Dovecot system. It shouldn't have access to anything
21293 Defaults to @samp{"dovenull"}.
21296 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
21297 Internal user is used by unprivileged processes. It should be
21298 separate from login user, so that login processes can't disturb other
21300 Defaults to @samp{"dovecot"}.
21303 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
21304 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
21305 Defaults to @samp{"required"}.
21308 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
21309 PEM encoded X.509 SSL/TLS certificate (public key).
21310 Defaults to @samp{"</etc/dovecot/default.pem"}.
21313 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
21314 PEM encoded SSL/TLS private key. The key is opened before
21315 dropping root privileges, so keep the key file unreadable by anyone but
21317 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
21320 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
21321 If key file is password protected, give the password here.
21322 Alternatively give it when starting dovecot with -p parameter. Since
21323 this file is often world-readable, you may want to place this setting
21324 instead to a different.
21325 Defaults to @samp{""}.
21328 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
21329 PEM encoded trusted certificate authority. Set this only if you
21330 intend to use @samp{ssl-verify-client-cert? #t}. The file should
21331 contain the CA certificate(s) followed by the matching
21332 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
21333 Defaults to @samp{""}.
21336 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
21337 Require that CRL check succeeds for client certificates.
21338 Defaults to @samp{#t}.
21341 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
21342 Request client to send a certificate. If you also want to require
21343 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
21344 Defaults to @samp{#f}.
21347 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
21348 Which field from certificate to use for username. commonName and
21349 x500UniqueIdentifier are the usual choices. You'll also need to set
21350 @samp{auth-ssl-username-from-cert? #t}.
21351 Defaults to @samp{"commonName"}.
21354 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
21355 Minimum SSL protocol version to accept.
21356 Defaults to @samp{"TLSv1"}.
21359 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
21360 SSL ciphers to use.
21361 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
21364 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
21365 SSL crypto device to use, for valid values run "openssl engine".
21366 Defaults to @samp{""}.
21369 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
21370 Address to use when sending rejection mails.
21371 %d expands to recipient domain.
21372 Defaults to @samp{"postmaster@@%d"}.
21375 @deftypevr {@code{dovecot-configuration} parameter} string hostname
21376 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
21377 and in LMTP replies. Default is the system's real hostname@@domain.
21378 Defaults to @samp{""}.
21381 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
21382 If user is over quota, return with temporary failure instead of
21384 Defaults to @samp{#f}.
21387 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
21388 Binary to use for sending mails.
21389 Defaults to @samp{"/usr/sbin/sendmail"}.
21392 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
21393 If non-empty, send mails via this SMTP host[:port] instead of
21395 Defaults to @samp{""}.
21398 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
21399 Subject: header to use for rejection mails. You can use the same
21400 variables as for @samp{rejection-reason} below.
21401 Defaults to @samp{"Rejected: %s"}.
21404 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
21405 Human readable error message for rejection mails. You can use
21418 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
21421 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
21422 Delimiter character between local-part and detail in email
21424 Defaults to @samp{"+"}.
21427 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
21428 Header where the original recipient address (SMTP's RCPT TO:
21429 address) is taken from if not available elsewhere. With dovecot-lda -a
21430 parameter overrides this. A commonly used header for this is
21432 Defaults to @samp{""}.
21435 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
21436 Should saving a mail to a nonexistent mailbox automatically create
21438 Defaults to @samp{#f}.
21441 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
21442 Should automatically created mailboxes be also automatically
21444 Defaults to @samp{#f}.
21447 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
21448 Maximum IMAP command line length. Some clients generate very long
21449 command lines with huge mailboxes, so you may need to raise this if you
21450 get "Too long argument" or "IMAP command line too large" errors
21452 Defaults to @samp{64000}.
21455 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
21456 IMAP logout format string:
21459 total number of bytes read from client
21461 total number of bytes sent to client.
21463 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
21464 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@}"}.
21467 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
21468 Override the IMAP CAPABILITY response. If the value begins with '+',
21469 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
21470 Defaults to @samp{""}.
21473 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
21474 How long to wait between "OK Still here" notifications when client
21476 Defaults to @samp{"2 mins"}.
21479 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
21480 ID field names and values to send to clients. Using * as the value
21481 makes Dovecot use the default value. The following fields have default
21482 values currently: name, version, os, os-version, support-url,
21484 Defaults to @samp{""}.
21487 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
21488 ID fields sent by client to log. * means everything.
21489 Defaults to @samp{""}.
21492 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
21493 Workarounds for various client bugs:
21496 @item delay-newmail
21497 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
21498 CHECK commands. Some clients ignore them otherwise, for example OSX
21499 Mail (<v2.1). Outlook Express breaks more badly though, without this it
21500 may show user "Message no longer in server" errors. Note that OE6
21501 still breaks even with this workaround if synchronization is set to
21504 @item tb-extra-mailbox-sep
21505 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
21506 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
21507 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
21509 @item tb-lsub-flags
21510 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
21511 This makes Thunderbird realize they aren't selectable and show them
21512 greyed out, instead of only later giving "not selectable" popup error.
21514 Defaults to @samp{()}.
21517 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
21518 Host allowed in URLAUTH URLs sent by client. "*" allows all.
21519 Defaults to @samp{""}.
21523 Whew! Lots of configuration options. The nice thing about it though is
21524 that Guix has a complete interface to Dovecot's configuration
21525 language. This allows not only a nice way to declare configurations,
21526 but also offers reflective capabilities as well: users can write code to
21527 inspect and transform configurations from within Scheme.
21529 However, it could be that you just want to get a @code{dovecot.conf} up
21530 and running. In that case, you can pass an
21531 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
21532 @code{dovecot-service}. As its name indicates, an opaque configuration
21533 does not have easy reflective capabilities.
21535 Available @code{opaque-dovecot-configuration} fields are:
21537 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
21538 The dovecot package.
21541 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
21542 The contents of the @code{dovecot.conf}, as a string.
21545 For example, if your @code{dovecot.conf} is just the empty string, you
21546 could instantiate a dovecot service like this:
21549 (dovecot-service #:config
21550 (opaque-dovecot-configuration
21554 @subsubheading OpenSMTPD Service
21556 @deffn {Scheme Variable} opensmtpd-service-type
21557 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
21558 service, whose value should be an @code{opensmtpd-configuration} object
21559 as in this example:
21562 (service opensmtpd-service-type
21563 (opensmtpd-configuration
21564 (config-file (local-file "./my-smtpd.conf"))))
21568 @deftp {Data Type} opensmtpd-configuration
21569 Data type representing the configuration of opensmtpd.
21572 @item @code{package} (default: @var{opensmtpd})
21573 Package object of the OpenSMTPD SMTP server.
21575 @item @code{config-file} (default: @code{%default-opensmtpd-file})
21576 File-like object of the OpenSMTPD configuration file to use. By default
21577 it listens on the loopback network interface, and allows for mail from
21578 users and daemons on the local machine, as well as permitting email to
21579 remote servers. Run @command{man smtpd.conf} for more information.
21584 @subsubheading Exim Service
21586 @cindex mail transfer agent (MTA)
21587 @cindex MTA (mail transfer agent)
21590 @deffn {Scheme Variable} exim-service-type
21591 This is the type of the @uref{https://exim.org, Exim} mail transfer
21592 agent (MTA), whose value should be an @code{exim-configuration} object
21593 as in this example:
21596 (service exim-service-type
21597 (exim-configuration
21598 (config-file (local-file "./my-exim.conf"))))
21602 In order to use an @code{exim-service-type} service you must also have a
21603 @code{mail-aliases-service-type} service present in your
21604 @code{operating-system} (even if it has no aliases).
21606 @deftp {Data Type} exim-configuration
21607 Data type representing the configuration of exim.
21610 @item @code{package} (default: @var{exim})
21611 Package object of the Exim server.
21613 @item @code{config-file} (default: @code{#f})
21614 File-like object of the Exim configuration file to use. If its value is
21615 @code{#f} then use the default configuration file from the package
21616 provided in @code{package}. The resulting configuration file is loaded
21617 after setting the @code{exim_user} and @code{exim_group} configuration
21623 @subsubheading Getmail service
21628 @deffn {Scheme Variable} getmail-service-type
21629 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
21630 mail retriever, whose value should be an @code{getmail-configuration}.
21633 Available @code{getmail-configuration} fields are:
21635 @deftypevr {@code{getmail-configuration} parameter} symbol name
21636 A symbol to identify the getmail service.
21638 Defaults to @samp{"unset"}.
21642 @deftypevr {@code{getmail-configuration} parameter} package package
21643 The getmail package to use.
21647 @deftypevr {@code{getmail-configuration} parameter} string user
21648 The user to run getmail as.
21650 Defaults to @samp{"getmail"}.
21654 @deftypevr {@code{getmail-configuration} parameter} string group
21655 The group to run getmail as.
21657 Defaults to @samp{"getmail"}.
21661 @deftypevr {@code{getmail-configuration} parameter} string directory
21662 The getmail directory to use.
21664 Defaults to @samp{"/var/lib/getmail/default"}.
21668 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
21669 The getmail configuration file to use.
21671 Available @code{getmail-configuration-file} fields are:
21673 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
21674 What mail account to retrieve mail from, and how to access that account.
21676 Available @code{getmail-retriever-configuration} fields are:
21678 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
21679 The type of mail retriever to use. Valid values include @samp{passwd}
21682 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
21686 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
21687 Username to login to the mail server with.
21689 Defaults to @samp{unset}.
21693 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
21694 Username to login to the mail server with.
21696 Defaults to @samp{unset}.
21700 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
21701 Port number to connect to.
21703 Defaults to @samp{#f}.
21707 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
21708 Override fields from passwd.
21710 Defaults to @samp{""}.
21714 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
21715 Override fields from passwd.
21717 Defaults to @samp{()}.
21721 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
21722 PEM-formatted key file to use for the TLS negotiation.
21724 Defaults to @samp{""}.
21728 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
21729 PEM-formatted certificate file to use for the TLS negotiation.
21731 Defaults to @samp{""}.
21735 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
21736 CA certificates to use.
21738 Defaults to @samp{""}.
21742 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
21743 Extra retriever parameters.
21745 Defaults to @samp{()}.
21751 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
21752 What to do with retrieved messages.
21754 Available @code{getmail-destination-configuration} fields are:
21756 @deftypevr {@code{getmail-destination-configuration} parameter} string type
21757 The type of mail destination. Valid values include @samp{Maildir},
21758 @samp{Mboxrd} and @samp{MDA_external}.
21760 Defaults to @samp{unset}.
21764 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
21765 The path option for the mail destination. The behaviour depends on the
21768 Defaults to @samp{""}.
21772 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
21773 Extra destination parameters
21775 Defaults to @samp{()}.
21781 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
21784 Available @code{getmail-options-configuration} fields are:
21786 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21787 If set to @samp{0}, getmail will only print warnings and errors. A
21788 value of @samp{1} means that messages will be printed about retrieving
21789 and deleting messages. If set to @samp{2}, getmail will print messages
21790 about each of its actions.
21792 Defaults to @samp{1}.
21796 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21797 If true, getmail will retrieve all available messages. Otherwise it
21798 will only retrieve messages it hasn't seen previously.
21800 Defaults to @samp{#t}.
21804 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21805 If set to true, messages will be deleted from the server after
21806 retrieving and successfully delivering them. Otherwise, messages will
21807 be left on the server.
21809 Defaults to @samp{#f}.
21813 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21814 Getmail will delete messages this number of days after seeing them, if
21815 they have been delivered. This means messages will be left on the
21816 server this number of days after delivering them. A value of @samp{0}
21817 disabled this feature.
21819 Defaults to @samp{0}.
21823 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21824 Delete messages larger than this of bytes after retrieving them, even if
21825 the delete and delete-after options are disabled. A value of @samp{0}
21826 disables this feature.
21828 Defaults to @samp{0}.
21832 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21833 Retrieve messages totalling up to this number of bytes before closing
21834 the session with the server. A value of @samp{0} disables this feature.
21836 Defaults to @samp{0}.
21840 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21841 Don't retrieve messages larger than this number of bytes. A value of
21842 @samp{0} disables this feature.
21844 Defaults to @samp{0}.
21848 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21849 If true, getmail will add a Delivered-To header to messages.
21851 Defaults to @samp{#t}.
21855 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21856 If set, getmail adds a Received header to the messages.
21858 Defaults to @samp{#t}.
21862 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21863 Getmail will record a log of its actions to the named file. A value of
21864 @samp{""} disables this feature.
21866 Defaults to @samp{""}.
21870 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21871 If true, getmail will record a log of its actions using the system
21874 Defaults to @samp{#f}.
21878 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21879 If true, getmail will log information about messages not retrieved and
21880 the reason for not retrieving them, as well as starting and ending
21883 Defaults to @samp{#f}.
21887 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21888 Extra options to include.
21890 Defaults to @samp{()}.
21898 @deftypevr {@code{getmail-configuration} parameter} list idle
21899 A list of mailboxes that getmail should wait on the server for new mail
21900 notifications. This depends on the server supporting the IDLE
21903 Defaults to @samp{()}.
21907 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21908 Environment variables to set for getmail.
21910 Defaults to @samp{()}.
21914 @subsubheading Mail Aliases Service
21916 @cindex email aliases
21917 @cindex aliases, for email addresses
21919 @deffn {Scheme Variable} mail-aliases-service-type
21920 This is the type of the service which provides @code{/etc/aliases},
21921 specifying how to deliver mail to users on this system.
21924 (service mail-aliases-service-type
21925 '(("postmaster" "bob")
21926 ("bob" "bob@@example.com" "bob@@example2.com")))
21930 The configuration for a @code{mail-aliases-service-type} service is an
21931 association list denoting how to deliver mail that comes to this
21932 system. Each entry is of the form @code{(alias addresses ...)}, with
21933 @code{alias} specifying the local alias and @code{addresses} specifying
21934 where to deliver this user's mail.
21936 The aliases aren't required to exist as users on the local system. In
21937 the above example, there doesn't need to be a @code{postmaster} entry in
21938 the @code{operating-system}'s @code{user-accounts} in order to deliver
21939 the @code{postmaster} mail to @code{bob} (which subsequently would
21940 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21942 @subsubheading GNU Mailutils IMAP4 Daemon
21943 @cindex GNU Mailutils IMAP4 Daemon
21945 @deffn {Scheme Variable} imap4d-service-type
21946 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21947 mailutils, GNU Mailutils Manual}), whose value should be an
21948 @code{imap4d-configuration} object as in this example:
21951 (service imap4d-service-type
21952 (imap4d-configuration
21953 (config-file (local-file "imap4d.conf"))))
21957 @deftp {Data Type} imap4d-configuration
21958 Data type representing the configuration of @command{imap4d}.
21961 @item @code{package} (default: @code{mailutils})
21962 The package that provides @command{imap4d}.
21964 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21965 File-like object of the configuration file to use, by default it will listen
21966 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21967 Mailutils Manual}, for details.
21972 @subsubheading Radicale Service
21976 @deffn {Scheme Variable} radicale-service-type
21977 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
21978 server whose value should be a @code{radicale-configuration}.
21981 @deftp {Data Type} radicale-configuration
21982 Data type representing the configuration of @command{radicale}.
21985 @item @code{package} (default: @code{radicale})
21986 The package that provides @command{radicale}.
21988 @item @code{config-file} (default: @code{%default-radicale-config-file})
21989 File-like object of the configuration file to use, by default it will listen
21990 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
21991 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
21996 @node Messaging Services
21997 @subsection Messaging Services
22002 The @code{(gnu services messaging)} module provides Guix service
22003 definitions for messaging services. Currently it provides the following
22006 @subsubheading Prosody Service
22008 @deffn {Scheme Variable} prosody-service-type
22009 This is the type for the @uref{https://prosody.im, Prosody XMPP
22010 communication server}. Its value must be a @code{prosody-configuration}
22011 record as in this example:
22014 (service prosody-service-type
22015 (prosody-configuration
22016 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
22019 (int-component-configuration
22020 (hostname "conference.example.net")
22022 (mod-muc (mod-muc-configuration)))))
22025 (virtualhost-configuration
22026 (domain "example.net"))))))
22029 See below for details about @code{prosody-configuration}.
22033 By default, Prosody does not need much configuration. Only one
22034 @code{virtualhosts} field is needed: it specifies the domain you wish
22037 You can perform various sanity checks on the generated configuration
22038 with the @code{prosodyctl check} command.
22040 Prosodyctl will also help you to import certificates from the
22041 @code{letsencrypt} directory so that the @code{prosody} user can access
22042 them. See @url{https://prosody.im/doc/letsencrypt}.
22045 prosodyctl --root cert import /etc/letsencrypt/live
22048 The available configuration parameters follow. Each parameter
22049 definition is preceded by its type; for example, @samp{string-list foo}
22050 indicates that the @code{foo} parameter should be specified as a list of
22051 strings. Types starting with @code{maybe-} denote parameters that won't
22052 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
22054 There is also a way to specify the configuration as a string, if you
22055 have an old @code{prosody.cfg.lua} file that you want to port over from
22056 some other system; see the end for more details.
22058 The @code{file-object} type designates either a file-like object
22059 (@pxref{G-Expressions, file-like objects}) or a file name.
22061 @c The following documentation was initially generated by
22062 @c (generate-documentation) in (gnu services messaging). Manually maintained
22063 @c documentation is better, so we shouldn't hesitate to edit below as
22064 @c needed. However if the change you want to make to this documentation
22065 @c can be done in an automated way, it's probably easier to change
22066 @c (generate-documentation) than to make it below and have to deal with
22067 @c the churn as Prosody updates.
22069 Available @code{prosody-configuration} fields are:
22071 @deftypevr {@code{prosody-configuration} parameter} package prosody
22072 The Prosody package.
22075 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
22076 Location of the Prosody data storage directory. See
22077 @url{https://prosody.im/doc/configure}.
22078 Defaults to @samp{"/var/lib/prosody"}.
22081 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
22082 Additional plugin directories. They are searched in all the specified
22083 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
22084 Defaults to @samp{()}.
22087 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
22088 Every virtual host and component needs a certificate so that clients and
22089 servers can securely verify its identity. Prosody will automatically load
22090 certificates/keys from the directory specified here.
22091 Defaults to @samp{"/etc/prosody/certs"}.
22094 @deftypevr {@code{prosody-configuration} parameter} string-list admins
22095 This is a list of accounts that are admins for the server. Note that you
22096 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
22097 @url{https://prosody.im/doc/creating_accounts}.
22098 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
22099 Defaults to @samp{()}.
22102 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
22103 Enable use of libevent for better performance under high load. See
22104 @url{https://prosody.im/doc/libevent}.
22105 Defaults to @samp{#f}.
22108 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
22109 This is the list of modules Prosody will load on startup. It looks for
22110 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
22111 Documentation on modules can be found at:
22112 @url{https://prosody.im/doc/modules}.
22113 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
22116 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
22117 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
22118 should you want to disable them then add them to this list.
22119 Defaults to @samp{()}.
22122 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
22123 Path to a text file where the shared groups are defined. If this path is
22124 empty then @samp{mod_groups} does nothing. See
22125 @url{https://prosody.im/doc/modules/mod_groups}.
22126 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
22129 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
22130 Disable account creation by default, for security. See
22131 @url{https://prosody.im/doc/creating_accounts}.
22132 Defaults to @samp{#f}.
22135 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
22136 These are the SSL/TLS-related settings. Most of them are disabled so to
22137 use Prosody's defaults. If you do not completely understand these options, do
22138 not add them to your config, it is easy to lower the security of your server
22139 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
22141 Available @code{ssl-configuration} fields are:
22143 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
22144 This determines what handshake to use.
22147 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
22148 Path to your private key file.
22151 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
22152 Path to your certificate file.
22155 @deftypevr {@code{ssl-configuration} parameter} file-object capath
22156 Path to directory containing root certificates that you wish Prosody to
22157 trust when verifying the certificates of remote servers.
22158 Defaults to @samp{"/etc/ssl/certs"}.
22161 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
22162 Path to a file containing root certificates that you wish Prosody to trust.
22163 Similar to @code{capath} but with all certificates concatenated together.
22166 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
22167 A list of verification options (these mostly map to OpenSSL's
22168 @code{set_verify()} flags).
22171 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
22172 A list of general options relating to SSL/TLS@. These map to OpenSSL's
22173 @code{set_options()}. For a full list of options available in LuaSec, see the
22177 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
22178 How long a chain of certificate authorities to check when looking for a
22179 trusted root certificate.
22182 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
22183 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
22184 clients, and in what order.
22187 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
22188 A path to a file containing parameters for Diffie-Hellman key exchange. You
22189 can create such a file with:
22190 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
22193 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
22194 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
22195 @samp{"secp384r1"}.
22198 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
22199 A list of ``extra'' verification options.
22202 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
22203 Password for encrypted private keys.
22208 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
22209 Whether to force all client-to-server connections to be encrypted or not.
22210 See @url{https://prosody.im/doc/modules/mod_tls}.
22211 Defaults to @samp{#f}.
22214 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
22215 Set of mechanisms that will never be offered. See
22216 @url{https://prosody.im/doc/modules/mod_saslauth}.
22217 Defaults to @samp{("DIGEST-MD5")}.
22220 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
22221 Whether to force all server-to-server connections to be encrypted or not.
22222 See @url{https://prosody.im/doc/modules/mod_tls}.
22223 Defaults to @samp{#f}.
22226 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
22227 Whether to require encryption and certificate authentication. This
22228 provides ideal security, but requires servers you communicate with to support
22229 encryption AND present valid, trusted certificates. See
22230 @url{https://prosody.im/doc/s2s#security}.
22231 Defaults to @samp{#f}.
22234 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
22235 Many servers don't support encryption or have invalid or self-signed
22236 certificates. You can list domains here that will not be required to
22237 authenticate using certificates. They will be authenticated using DNS@. See
22238 @url{https://prosody.im/doc/s2s#security}.
22239 Defaults to @samp{()}.
22242 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
22243 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
22244 valid certificates for some domains by specifying a list here. See
22245 @url{https://prosody.im/doc/s2s#security}.
22246 Defaults to @samp{()}.
22249 @deftypevr {@code{prosody-configuration} parameter} string authentication
22250 Select the authentication backend to use. The default provider stores
22251 passwords in plaintext and uses Prosody's configured data storage to store the
22252 authentication data. If you do not trust your server please see
22253 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
22254 about using the hashed backend. See also
22255 @url{https://prosody.im/doc/authentication}
22256 Defaults to @samp{"internal_plain"}.
22259 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
22260 Set logging options. Advanced logging configuration is not yet supported
22261 by the Prosody service. See @url{https://prosody.im/doc/logging}.
22262 Defaults to @samp{"*syslog"}.
22265 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
22266 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
22267 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
22270 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
22271 Maximum allowed size of the HTTP body (in bytes).
22274 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
22275 Some modules expose their own URL in various ways. This URL is built
22276 from the protocol, host and port used. If Prosody sits behind a proxy, the
22277 public URL will be @code{http-external-url} instead. See
22278 @url{https://prosody.im/doc/http#external_url}.
22281 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
22282 A host in Prosody is a domain on which user accounts can be created. For
22283 example if you want your users to have addresses like
22284 @samp{"john.smith@@example.com"} then you need to add a host
22285 @samp{"example.com"}. All options in this list will apply only to this host.
22287 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
22288 the actual physical host that Prosody is installed on. A single Prosody
22289 instance can serve many domains, each one defined as a VirtualHost entry in
22290 Prosody's configuration. Conversely a server that hosts a single domain would
22291 have just one VirtualHost entry.
22293 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
22295 Available @code{virtualhost-configuration} fields are:
22297 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:
22298 @deftypevr {@code{virtualhost-configuration} parameter} string domain
22299 Domain you wish Prosody to serve.
22304 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
22305 Components are extra services on a server which are available to clients,
22306 usually on a subdomain of the main server (such as
22307 @samp{"mycomponent.example.com"}). Example components might be chatroom
22308 servers, user directories, or gateways to other protocols.
22310 Internal components are implemented with Prosody-specific plugins. To add an
22311 internal component, you simply fill the hostname field, and the plugin you wish
22312 to use for the component.
22314 See @url{https://prosody.im/doc/components}.
22315 Defaults to @samp{()}.
22317 Available @code{int-component-configuration} fields are:
22319 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:
22320 @deftypevr {@code{int-component-configuration} parameter} string hostname
22321 Hostname of the component.
22324 @deftypevr {@code{int-component-configuration} parameter} string plugin
22325 Plugin you wish to use for the component.
22328 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
22329 Multi-user chat (MUC) is Prosody's module for allowing you to create
22330 hosted chatrooms/conferences for XMPP users.
22332 General information on setting up and using multi-user chatrooms can be found
22333 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
22334 which you should read if you are new to XMPP chatrooms.
22336 See also @url{https://prosody.im/doc/modules/mod_muc}.
22338 Available @code{mod-muc-configuration} fields are:
22340 @deftypevr {@code{mod-muc-configuration} parameter} string name
22341 The name to return in service discovery responses.
22342 Defaults to @samp{"Prosody Chatrooms"}.
22345 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
22346 If @samp{#t}, this will only allow admins to create new chatrooms.
22347 Otherwise anyone can create a room. The value @samp{"local"} restricts room
22348 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
22349 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
22350 restricts to service administrators only.
22351 Defaults to @samp{#f}.
22354 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
22355 Maximum number of history messages that will be sent to the member that has
22356 just joined the room.
22357 Defaults to @samp{20}.
22364 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
22365 External components use XEP-0114, which most standalone components
22366 support. To add an external component, you simply fill the hostname field. See
22367 @url{https://prosody.im/doc/components}.
22368 Defaults to @samp{()}.
22370 Available @code{ext-component-configuration} fields are:
22372 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:
22373 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
22374 Password which the component will use to log in.
22377 @deftypevr {@code{ext-component-configuration} parameter} string hostname
22378 Hostname of the component.
22383 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
22384 Port(s) Prosody listens on for component connections.
22385 Defaults to @samp{(5347)}.
22388 @deftypevr {@code{prosody-configuration} parameter} string component-interface
22389 Interface Prosody listens on for component connections.
22390 Defaults to @samp{"127.0.0.1"}.
22393 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
22394 Raw content that will be added to the configuration file.
22397 It could be that you just want to get a @code{prosody.cfg.lua}
22398 up and running. In that case, you can pass an
22399 @code{opaque-prosody-configuration} record as the value of
22400 @code{prosody-service-type}. As its name indicates, an opaque configuration
22401 does not have easy reflective capabilities.
22402 Available @code{opaque-prosody-configuration} fields are:
22404 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
22405 The prosody package.
22408 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
22409 The contents of the @code{prosody.cfg.lua} to use.
22412 For example, if your @code{prosody.cfg.lua} is just the empty
22413 string, you could instantiate a prosody service like this:
22416 (service prosody-service-type
22417 (opaque-prosody-configuration
22418 (prosody.cfg.lua "")))
22421 @c end of Prosody auto-generated documentation
22423 @subsubheading BitlBee Service
22425 @cindex IRC (Internet Relay Chat)
22426 @cindex IRC gateway
22427 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
22428 interface to a variety of messaging protocols such as XMPP.
22430 @defvr {Scheme Variable} bitlbee-service-type
22431 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
22432 gateway daemon. Its value is a @code{bitlbee-configuration} (see
22435 To have BitlBee listen on port 6667 on localhost, add this line to your
22439 (service bitlbee-service-type)
22443 @deftp {Data Type} bitlbee-configuration
22444 This is the configuration for BitlBee, with the following fields:
22447 @item @code{interface} (default: @code{"127.0.0.1"})
22448 @itemx @code{port} (default: @code{6667})
22449 Listen on the network interface corresponding to the IP address
22450 specified in @var{interface}, on @var{port}.
22452 When @var{interface} is @code{127.0.0.1}, only local clients can
22453 connect; when it is @code{0.0.0.0}, connections can come from any
22454 networking interface.
22456 @item @code{bitlbee} (default: @code{bitlbee})
22457 The BitlBee package to use.
22459 @item @code{plugins} (default: @code{'()})
22460 List of plugin packages to use---e.g., @code{bitlbee-discord}.
22462 @item @code{extra-settings} (default: @code{""})
22463 Configuration snippet added as-is to the BitlBee configuration file.
22467 @subsubheading Quassel Service
22469 @cindex IRC (Internet Relay Chat)
22470 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
22471 meaning that one or more clients can attach to and detach from the
22474 @defvr {Scheme Variable} quassel-service-type
22475 This is the service type for the @url{https://quassel-irc.org/,Quassel}
22476 IRC backend daemon. Its value is a @code{quassel-configuration}
22480 @deftp {Data Type} quassel-configuration
22481 This is the configuration for Quassel, with the following fields:
22484 @item @code{quassel} (default: @code{quassel})
22485 The Quassel package to use.
22487 @item @code{interface} (default: @code{"::,0.0.0.0"})
22488 @item @code{port} (default: @code{4242})
22489 Listen on the network interface(s) corresponding to the IPv4 or IPv6
22490 interfaces specified in the comma delimited @var{interface}, on
22493 @item @code{loglevel} (default: @code{"Info"})
22494 The level of logging desired. Accepted values are Debug, Info, Warning
22499 @node Telephony Services
22500 @subsection Telephony Services
22502 @cindex Murmur (VoIP server)
22503 @cindex VoIP server
22504 This section describes how to set up and run a Murmur server. Murmur is
22505 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
22508 @deftp {Data Type} murmur-configuration
22509 The service type for the Murmur server. An example configuration can
22513 (service murmur-service-type
22514 (murmur-configuration
22516 "Welcome to this Mumble server running on Guix!")
22517 (cert-required? #t) ;disallow text password logins
22518 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
22519 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
22522 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
22523 password with the command that is printed during the activation phase.
22525 It is recommended to register a normal Mumble user account
22526 and grant it admin or moderator rights.
22527 You can use the @code{mumble} client to
22528 login as new normal user, register yourself, and log out.
22529 For the next step login with the name @code{SuperUser} use
22530 the @code{SuperUser} password that you set previously,
22531 and grant your newly registered mumble user administrator or moderator
22532 rights and create some channels.
22534 Available @code{murmur-configuration} fields are:
22537 @item @code{package} (default: @code{mumble})
22538 Package that contains @code{bin/murmurd}.
22540 @item @code{user} (default: @code{"murmur"})
22541 User who will run the Murmur server.
22543 @item @code{group} (default: @code{"murmur"})
22544 Group of the user who will run the murmur server.
22546 @item @code{port} (default: @code{64738})
22547 Port on which the server will listen.
22549 @item @code{welcome-text} (default: @code{""})
22550 Welcome text sent to clients when they connect.
22552 @item @code{server-password} (default: @code{""})
22553 Password the clients have to enter in order to connect.
22555 @item @code{max-users} (default: @code{100})
22556 Maximum of users that can be connected to the server at once.
22558 @item @code{max-user-bandwidth} (default: @code{#f})
22559 Maximum voice traffic a user can send per second.
22561 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
22562 File name of the sqlite database.
22563 The service's user will become the owner of the directory.
22565 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
22566 File name of the log file.
22567 The service's user will become the owner of the directory.
22569 @item @code{autoban-attempts} (default: @code{10})
22570 Maximum number of logins a user can make in @code{autoban-timeframe}
22571 without getting auto banned for @code{autoban-time}.
22573 @item @code{autoban-timeframe} (default: @code{120})
22574 Timeframe for autoban in seconds.
22576 @item @code{autoban-time} (default: @code{300})
22577 Amount of time in seconds for which a client gets banned
22578 when violating the autoban limits.
22580 @item @code{opus-threshold} (default: @code{100})
22581 Percentage of clients that need to support opus
22582 before switching over to opus audio codec.
22584 @item @code{channel-nesting-limit} (default: @code{10})
22585 How deep channels can be nested at maximum.
22587 @item @code{channelname-regex} (default: @code{#f})
22588 A string in form of a Qt regular expression that channel names must conform to.
22590 @item @code{username-regex} (default: @code{#f})
22591 A string in form of a Qt regular expression that user names must conform to.
22593 @item @code{text-message-length} (default: @code{5000})
22594 Maximum size in bytes that a user can send in one text chat message.
22596 @item @code{image-message-length} (default: @code{(* 128 1024)})
22597 Maximum size in bytes that a user can send in one image message.
22599 @item @code{cert-required?} (default: @code{#f})
22600 If it is set to @code{#t} clients that use weak password authentication
22601 will not be accepted. Users must have completed the certificate wizard to join.
22603 @item @code{remember-channel?} (default: @code{#f})
22604 Should murmur remember the last channel each user was in when they disconnected
22605 and put them into the remembered channel when they rejoin.
22607 @item @code{allow-html?} (default: @code{#f})
22608 Should html be allowed in text messages, user comments, and channel descriptions.
22610 @item @code{allow-ping?} (default: @code{#f})
22611 Setting to true exposes the current user count, the maximum user count, and
22612 the server's maximum bandwidth per client to unauthenticated users. In the
22613 Mumble client, this information is shown in the Connect dialog.
22615 Disabling this setting will prevent public listing of the server.
22617 @item @code{bonjour?} (default: @code{#f})
22618 Should the server advertise itself in the local network through the bonjour protocol.
22620 @item @code{send-version?} (default: @code{#f})
22621 Should the murmur server version be exposed in ping requests.
22623 @item @code{log-days} (default: @code{31})
22624 Murmur also stores logs in the database, which are accessible via RPC.
22625 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
22626 or -1 to disable logging to the database.
22628 @item @code{obfuscate-ips?} (default: @code{#t})
22629 Should logged ips be obfuscated to protect the privacy of users.
22631 @item @code{ssl-cert} (default: @code{#f})
22632 File name of the SSL/TLS certificate used for encrypted connections.
22635 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
22637 @item @code{ssl-key} (default: @code{#f})
22638 Filepath to the ssl private key used for encrypted connections.
22640 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
22643 @item @code{ssl-dh-params} (default: @code{#f})
22644 File name of a PEM-encoded file with Diffie-Hellman parameters
22645 for the SSL/TLS encryption. Alternatively you set it to
22646 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
22647 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
22649 @item @code{ssl-ciphers} (default: @code{#f})
22650 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
22653 This option is specified using
22654 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
22655 OpenSSL cipher list notation}.
22657 It is recommended that you try your cipher string using 'openssl ciphers <string>'
22658 before setting it here, to get a feel for which cipher suites you will get.
22659 After setting this option, it is recommend that you inspect your Murmur log
22660 to ensure that Murmur is using the cipher suites that you expected it to.
22662 Note: Changing this option may impact the backwards compatibility of your
22663 Murmur server, and can remove the ability for older Mumble clients to be able
22666 @item @code{public-registration} (default: @code{#f})
22667 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
22669 You can optionally register your server in the public server list that the
22670 @code{mumble} client shows on startup.
22671 You cannot register your server if you have set a @code{server-password},
22672 or set @code{allow-ping} to @code{#f}.
22674 It might take a few hours until it shows up in the public list.
22676 @item @code{file} (default: @code{#f})
22677 Optional alternative override for this configuration.
22681 @deftp {Data Type} murmur-public-registration-configuration
22682 Configuration for public registration of a murmur service.
22686 This is a display name for your server. Not to be confused with the hostname.
22688 @item @code{password}
22689 A password to identify your registration.
22690 Subsequent updates will need the same password. Don't lose your password.
22693 This should be a @code{http://} or @code{https://} link to your web
22696 @item @code{hostname} (default: @code{#f})
22697 By default your server will be listed by its IP address.
22698 If it is set your server will be linked by this host name instead.
22704 @node File-Sharing Services
22705 @subsection File-Sharing Services
22707 The @code{(gnu services file-sharing)} module provides services that
22708 assist with transferring files over peer-to-peer file-sharing networks.
22710 @subsubheading Transmission Daemon Service
22712 @uref{https://transmissionbt.com/, Transmission} is a flexible
22713 BitTorrent client that offers a variety of graphical and command-line
22714 interfaces. A @code{transmission-daemon-service-type} service provides
22715 Transmission's headless variant, @command{transmission-daemon}, as a
22716 system service, allowing users to share files via BitTorrent even when
22717 they are not logged in.
22719 @deffn {Scheme Variable} transmission-daemon-service-type
22720 The service type for the Transmission Daemon BitTorrent client. Its
22721 value must be a @code{transmission-daemon-configuration} object as in
22725 (service transmission-daemon-service-type
22726 (transmission-daemon-configuration
22727 ;; Restrict access to the RPC ("control") interface
22728 (rpc-authentication-required? #t)
22729 (rpc-username "transmission")
22731 (transmission-password-hash
22732 "transmission" ; desired password
22733 "uKd1uMs9")) ; arbitrary salt value
22735 ;; Accept requests from this and other hosts on the
22737 (rpc-whitelist-enabled? #t)
22738 (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
22740 ;; Limit bandwidth use during work hours
22741 (alt-speed-down (* 1024 2)) ; 2 MB/s
22742 (alt-speed-up 512) ; 512 kB/s
22744 (alt-speed-time-enabled? #t)
22745 (alt-speed-time-day 'weekdays)
22746 (alt-speed-time-begin
22747 (+ (* 60 8) 30)) ; 8:30 am
22748 (alt-speed-time-end
22749 (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
22753 Once the service is started, users can interact with the daemon through
22754 its Web interface (at @code{http://localhost:9091/}) or by using the
22755 @command{transmission-remote} command-line tool, available in the
22756 @code{transmission} package. (Emacs users may want to also consider the
22757 @code{emacs-transmission} package.) Both communicate with the daemon
22758 through its remote procedure call (RPC) interface, which by default is
22759 available to all users on the system; you may wish to change this by
22760 assigning values to the @code{rpc-authentication-required?},
22761 @code{rpc-username} and @code{rpc-password} settings, as shown in the
22762 example above and documented further below.
22764 The value for @code{rpc-password} must be a password hash of the type
22765 generated and used by Transmission clients. This can be copied verbatim
22766 from an existing @file{settings.json} file, if another Transmission
22767 client is already being used. Otherwise, the
22768 @code{transmission-password-hash} and @code{transmission-random-salt}
22769 procedures provided by this module can be used to obtain a suitable hash
22772 @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
22773 Returns a string containing the result of hashing @var{password}
22774 together with @var{salt}, in the format recognized by Transmission
22775 clients for their @code{rpc-password} configuration setting.
22777 @var{salt} must be an eight-character string. The
22778 @code{transmission-random-salt} procedure can be used to generate a
22779 suitable salt value at random.
22782 @deffn {Scheme Procedure} transmission-random-salt
22783 Returns a string containing a random, eight-character salt value of the
22784 type generated and used by Transmission clients, suitable for passing to
22785 the @code{transmission-password-hash} procedure.
22788 These procedures are accessible from within a Guile REPL started with
22789 the @command{guix repl} command (@pxref{Invoking guix repl}). This is
22790 useful for obtaining a random salt value to provide as the second
22791 parameter to `transmission-password-hash`, as in this example session:
22795 scheme@@(guix-user)> ,use (gnu services file-sharing)
22796 scheme@@(guix-user)> (transmission-random-salt)
22800 Alternatively, a complete password hash can generated in a single step:
22803 scheme@@(guix-user)> (transmission-password-hash "transmission"
22804 (transmission-random-salt))
22805 $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
22808 The resulting string can be used as-is for the value of
22809 @code{rpc-password}, allowing the password to be kept hidden even in the
22810 operating-system configuration.
22812 Torrent files downloaded by the daemon are directly accessible only to
22813 users in the ``transmission'' user group, who receive read-only access
22814 to the directory specified by the @code{download-dir} configuration
22815 setting (and also the directory specified by @code{incomplete-dir}, if
22816 @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
22817 moved to another directory or deleted altogether using
22818 @command{transmission-remote} with its @code{--move} and
22819 @code{--remove-and-delete} options.
22821 If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
22822 the ``transmission'' group are able also to place @file{.torrent} files
22823 in the directory specified by @code{watch-dir} to have the corresponding
22824 torrents added by the daemon. (The @code{trash-original-torrent-files?}
22825 setting controls whether the daemon deletes these files after processing
22828 Some of the daemon's configuration settings can be changed temporarily
22829 by @command{transmission-remote} and similar tools. To undo these
22830 changes, use the service's @code{reload} action to have the daemon
22831 reload its settings from disk:
22834 # herd reload transmission-daemon
22837 The full set of available configuration settings is defined by the
22838 @code{transmission-daemon-configuration} data type.
22840 @deftp {Data Type} transmission-daemon-configuration
22841 The data type representing configuration settings for Transmission
22842 Daemon. These correspond directly to the settings recognized by
22843 Transmission clients in their @file{settings.json} file.
22846 @c The following documentation was initially generated by
22847 @c (generate-transmission-daemon-documentation) in (gnu services
22848 @c file-sharing). Manually maintained documentation is better, so we
22849 @c shouldn't hesitate to edit below as needed. However if the change
22850 @c you want to make to this documentation can be done in an automated
22851 @c way, it's probably easier to change (generate-documentation) than to
22852 @c make it below and have to deal with the churn as Transmission Daemon
22855 @c %start of fragment
22857 Available @code{transmission-daemon-configuration} fields are:
22859 @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
22860 The Transmission package to use.
22864 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
22865 The period, in seconds, to wait when stopping the service for
22866 @command{transmission-daemon} to exit before killing its process. This
22867 allows the daemon time to complete its housekeeping and send a final
22868 update to trackers as it shuts down. On slow hosts, or hosts with a
22869 slow network connection, this value may need to be increased.
22871 Defaults to @samp{10}.
22875 @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
22876 The directory to which torrent files are downloaded.
22878 Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
22882 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
22883 If @code{#t}, files will be held in @code{incomplete-dir} while their
22884 torrent is being downloaded, then moved to @code{download-dir} once the
22885 torrent is complete. Otherwise, files for all torrents (including those
22886 still being downloaded) will be placed in @code{download-dir}.
22888 Defaults to @samp{#f}.
22892 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
22893 The directory in which files from incompletely downloaded torrents will
22894 be held when @code{incomplete-dir-enabled?} is @code{#t}.
22896 Defaults to @samp{disabled}.
22900 @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
22901 The file mode creation mask used for downloaded files. (See the
22902 @command{umask} man page for more information.)
22904 Defaults to @samp{18}.
22908 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
22909 When @code{#t}, ``.part'' is appended to the name of partially
22912 Defaults to @samp{#t}.
22916 @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
22917 The mode by which space should be preallocated for downloaded files, one
22918 of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
22919 Specifying @code{full} will minimize disk fragmentation at a cost to
22920 file-creation speed.
22922 Defaults to @samp{fast}.
22926 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
22927 If @code{#t}, the directory specified by @code{watch-dir} will be
22928 watched for new @file{.torrent} files and the torrents they describe
22929 added automatically (and the original files removed, if
22930 @code{trash-original-torrent-files?} is @code{#t}).
22932 Defaults to @samp{#f}.
22936 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
22937 The directory to be watched for @file{.torrent} files indicating new
22938 torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
22940 Defaults to @samp{disabled}.
22944 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
22945 When @code{#t}, @file{.torrent} files will be deleted from the watch
22946 directory once their torrent has been added (see
22947 @code{watch-directory-enabled?}).
22949 Defaults to @samp{#f}.
22953 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
22954 When @code{#t}, the daemon's download speed will be limited to the rate
22955 specified by @code{speed-limit-down}.
22957 Defaults to @samp{#f}.
22961 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
22962 The default global-maximum download speed, in kilobytes per second.
22964 Defaults to @samp{100}.
22968 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
22969 When @code{#t}, the daemon's upload speed will be limited to the rate
22970 specified by @code{speed-limit-up}.
22972 Defaults to @samp{#f}.
22976 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
22977 The default global-maximum upload speed, in kilobytes per second.
22979 Defaults to @samp{100}.
22983 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
22984 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22985 @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
22986 @code{speed-limit-up}, if they are enabled) to constrain the daemon's
22987 bandwidth usage. This can be scheduled to occur automatically at
22988 certain times during the week; see @code{alt-speed-time-enabled?}.
22990 Defaults to @samp{#f}.
22994 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
22995 The alternate global-maximum download speed, in kilobytes per second.
22997 Defaults to @samp{50}.
23001 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
23002 The alternate global-maximum upload speed, in kilobytes per second.
23004 Defaults to @samp{50}.
23008 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
23009 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
23010 @code{alt-speed-up} will be enabled automatically during the periods
23011 specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
23012 @code{alt-time-speed-end}.
23014 Defaults to @samp{#f}.
23018 @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
23019 The days of the week on which the alternate-speed schedule should be
23020 used, specified either as a list of days (@code{sunday}, @code{monday},
23021 and so on) or using one of the symbols @code{weekdays}, @code{weekends}
23024 Defaults to @samp{all}.
23028 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
23029 The time of day at which to enable the alternate speed limits, expressed
23030 as a number of minutes since midnight.
23032 Defaults to @samp{540}.
23036 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
23037 The time of day at which to disable the alternate speed limits,
23038 expressed as a number of minutes since midnight.
23040 Defaults to @samp{1020}.
23044 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
23045 The IP address at which to listen for peer connections, or ``0.0.0.0''
23046 to listen at all available IP addresses.
23048 Defaults to @samp{"0.0.0.0"}.
23052 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
23053 The IPv6 address at which to listen for peer connections, or ``::'' to
23054 listen at all available IPv6 addresses.
23056 Defaults to @samp{"::"}.
23060 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
23061 If @code{#t}, when the daemon starts it will select a port at random on
23062 which to listen for peer connections, from the range specified
23063 (inclusively) by @code{peer-port-random-low} and
23064 @code{peer-port-random-high}. Otherwise, it listens on the port
23065 specified by @code{peer-port}.
23067 Defaults to @samp{#f}.
23071 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
23072 The lowest selectable port number when @code{peer-port-random-on-start?}
23075 Defaults to @samp{49152}.
23079 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
23080 The highest selectable port number when @code{peer-port-random-on-start}
23083 Defaults to @samp{65535}.
23087 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
23088 The port on which to listen for peer connections when
23089 @code{peer-port-random-on-start?} is @code{#f}.
23091 Defaults to @samp{51413}.
23095 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
23096 If @code{#t}, the daemon will attempt to configure port-forwarding on an
23097 upstream gateway automatically using @acronym{UPnP} and
23100 Defaults to @samp{#t}.
23104 @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
23105 The encryption preference for peer connections, one of
23106 @code{prefer-unencrypted-connections},
23107 @code{prefer-encrypted-connections} or
23108 @code{require-encrypted-connections}.
23110 Defaults to @samp{prefer-encrypted-connections}.
23114 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
23115 The TCP congestion-control algorithm to use for peer connections,
23116 specified using a string recognized by the operating system in calls to
23117 @code{setsockopt} (or set to @code{disabled}, in which case the
23118 operating-system default is used).
23120 Note that on GNU/Linux systems, the kernel must be configured to allow
23121 processes to use a congestion-control algorithm not in the default set;
23122 otherwise, it will deny these requests with ``Operation not permitted''.
23123 To see which algorithms are available on your system and which are
23124 currently permitted for use, look at the contents of the files
23125 @file{tcp_available_congestion_control} and
23126 @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
23129 As an example, to have Transmission Daemon use
23130 @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
23131 congestion-control algorithm}, you'll need to modify your kernel
23132 configuration to build in support for the algorithm, then update your
23133 operating-system configuration to allow its use by adding a
23134 @code{sysctl-service-type} service (or updating the existing one's
23135 configuration) with lines like the following:
23138 (service sysctl-service-type
23139 (sysctl-configuration
23141 ("net.ipv4.tcp_allowed_congestion_control" .
23142 "reno cubic lp"))))
23145 The Transmission Daemon configuration can then be updated with
23148 (peer-congestion-algorithm "lp")
23151 and the system reconfigured to have the changes take effect.
23153 Defaults to @samp{disabled}.
23157 @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
23158 The type of service to request in outgoing @acronym{TCP} packets, one of
23159 @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
23160 @code{reliability}.
23162 Defaults to @samp{default}.
23166 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
23167 The global limit on the number of connected peers.
23169 Defaults to @samp{200}.
23173 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
23174 The per-torrent limit on the number of connected peers.
23176 Defaults to @samp{50}.
23180 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
23181 The maximum number of peers to which the daemon will upload data
23182 simultaneously for each torrent.
23184 Defaults to @samp{14}.
23188 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
23189 The maximum lifespan, in hours, of the peer ID associated with each
23190 public torrent before it is regenerated.
23192 Defaults to @samp{6}.
23196 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
23197 When @code{#t}, the daemon will ignore peers mentioned in the blocklist
23198 it has most recently downloaded from @code{blocklist-url}.
23200 Defaults to @samp{#f}.
23204 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
23205 The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
23206 @file{.dat} format) to be periodically downloaded and applied when
23207 @code{blocklist-enabled?} is @code{#t}.
23209 Defaults to @samp{disabled}.
23213 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
23214 If @code{#t}, the daemon will be limited to downloading at most
23215 @code{download-queue-size} non-stalled torrents simultaneously.
23217 Defaults to @samp{#t}.
23221 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
23222 The size of the daemon's download queue, which limits the number of
23223 non-stalled torrents it will download at any one time when
23224 @code{download-queue-enabled?} is @code{#t}.
23226 Defaults to @samp{5}.
23230 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
23231 If @code{#t}, the daemon will be limited to seeding at most
23232 @code{seed-queue-size} non-stalled torrents simultaneously.
23234 Defaults to @samp{#f}.
23238 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
23239 The size of the daemon's seed queue, which limits the number of
23240 non-stalled torrents it will seed at any one time when
23241 @code{seed-queue-enabled?} is @code{#t}.
23243 Defaults to @samp{10}.
23247 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
23248 When @code{#t}, the daemon will consider torrents for which it has not
23249 shared data in the past @code{queue-stalled-minutes} minutes to be
23250 stalled and not count them against its @code{download-queue-size} and
23251 @code{seed-queue-size} limits.
23253 Defaults to @samp{#t}.
23257 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
23258 The maximum period, in minutes, a torrent may be idle before it is
23259 considered to be stalled, when @code{queue-stalled-enabled?} is
23262 Defaults to @samp{30}.
23266 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
23267 When @code{#t}, a torrent being seeded will automatically be paused once
23268 it reaches the ratio specified by @code{ratio-limit}.
23270 Defaults to @samp{#f}.
23274 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
23275 The ratio at which a torrent being seeded will be paused, when
23276 @code{ratio-limit-enabled?} is @code{#t}.
23278 Defaults to @samp{2.0}.
23282 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
23283 When @code{#t}, a torrent being seeded will automatically be paused once
23284 it has been idle for @code{idle-seeding-limit} minutes.
23286 Defaults to @samp{#f}.
23290 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
23291 The maximum period, in minutes, a torrent being seeded may be idle
23292 before it is paused, when @code{idle-seeding-limit-enabled?} is
23295 Defaults to @samp{30}.
23299 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
23300 Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
23301 hash table (@acronym{DHT}) protocol}, which supports the use of
23302 trackerless torrents.
23304 Defaults to @samp{#t}.
23308 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
23309 Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
23310 peer discovery} (@acronym{LPD}), which allows the discovery of peers on
23311 the local network and may reduce the amount of data sent over the public
23314 Defaults to @samp{#f}.
23318 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
23319 Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
23320 (@acronym{PEX}), which reduces the daemon's reliance on external
23321 trackers and may improve its performance.
23323 Defaults to @samp{#t}.
23327 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
23328 Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
23329 transport protocol} (@acronym{uTP}), which aims to reduce the impact of
23330 BitTorrent traffic on other users of the local network while maintaining
23331 full utilization of the available bandwidth.
23333 Defaults to @samp{#t}.
23337 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
23338 If @code{#t}, enable the remote procedure call (@acronym{RPC})
23339 interface, which allows remote control of the daemon via its Web
23340 interface, the @command{transmission-remote} command-line client, and
23343 Defaults to @samp{#t}.
23347 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
23348 The IP address at which to listen for @acronym{RPC} connections, or
23349 ``0.0.0.0'' to listen at all available IP addresses.
23351 Defaults to @samp{"0.0.0.0"}.
23355 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
23356 The port on which to listen for @acronym{RPC} connections.
23358 Defaults to @samp{9091}.
23362 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
23363 The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
23365 Defaults to @samp{"/transmission/"}.
23369 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
23370 When @code{#t}, clients must authenticate (see @code{rpc-username} and
23371 @code{rpc-password}) when using the @acronym{RPC} interface. Note this
23372 has the side effect of disabling host-name whitelisting (see
23373 @code{rpc-host-whitelist-enabled?}.
23375 Defaults to @samp{#f}.
23379 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
23380 The username required by clients to access the @acronym{RPC} interface
23381 when @code{rpc-authentication-required?} is @code{#t}.
23383 Defaults to @samp{disabled}.
23387 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
23388 The password required by clients to access the @acronym{RPC} interface
23389 when @code{rpc-authentication-required?} is @code{#t}. This must be
23390 specified using a password hash in the format recognized by Transmission
23391 clients, either copied from an existing @file{settings.json} file or
23392 generated using the @code{transmission-password-hash} procedure.
23394 Defaults to @samp{disabled}.
23398 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
23399 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23400 originate from an address specified in @code{rpc-whitelist}.
23402 Defaults to @samp{#t}.
23406 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
23407 The list of IP and IPv6 addresses from which @acronym{RPC} requests will
23408 be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
23409 may be specified using @samp{*}.
23411 Defaults to @samp{("127.0.0.1" "::1")}.
23415 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
23416 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23417 are addressed to a host named in @code{rpc-host-whitelist}. Note that
23418 requests to ``localhost'' or ``localhost.'', or to a numeric address,
23419 are always accepted regardless of these settings.
23421 Note also this functionality is disabled when
23422 @code{rpc-authentication-required?} is @code{#t}.
23424 Defaults to @samp{#t}.
23428 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
23429 The list of host names recognized by the @acronym{RPC} server when
23430 @code{rpc-host-whitelist-enabled?} is @code{#t}.
23432 Defaults to @samp{()}.
23436 @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
23437 The minimum severity level of messages to be logged (to
23438 @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
23439 logging), @code{error}, @code{info} and @code{debug}.
23441 Defaults to @samp{info}.
23445 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
23446 When @code{#t}, torrents are started as soon as they are added;
23447 otherwise, they are added in ``paused'' state.
23449 Defaults to @samp{#t}.
23453 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
23454 When @code{#t}, the script specified by
23455 @code{script-torrent-done-filename} will be invoked each time a torrent
23458 Defaults to @samp{#f}.
23462 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
23463 A file name or file-like object specifying a script to run each time a
23464 torrent completes, when @code{script-torrent-done-enabled?} is
23467 Defaults to @samp{disabled}.
23471 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
23472 When @code{#t}, the daemon will scrape trackers for a torrent even when
23473 the torrent is paused.
23475 Defaults to @samp{#t}.
23479 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
23480 The amount of memory, in megabytes, to allocate for the daemon's
23481 in-memory cache. A larger value may increase performance by reducing
23482 the frequency of disk I/O.
23484 Defaults to @samp{4}.
23488 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
23489 When @code{#t}, the daemon will try to improve I/O performance by
23490 hinting to the operating system which data is likely to be read next
23491 from disk to satisfy requests from peers.
23493 Defaults to @samp{#t}.
23498 @c %end of fragment
23502 @node Monitoring Services
23503 @subsection Monitoring Services
23505 @subsubheading Tailon Service
23507 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
23508 viewing and searching log files.
23510 The following example will configure the service with default values.
23511 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
23514 (service tailon-service-type)
23517 The following example customises more of the Tailon configuration,
23518 adding @command{sed} to the list of allowed commands.
23521 (service tailon-service-type
23522 (tailon-configuration
23524 (tailon-configuration-file
23525 (allowed-commands '("tail" "grep" "awk" "sed"))))))
23529 @deftp {Data Type} tailon-configuration
23530 Data type representing the configuration of Tailon.
23531 This type has the following parameters:
23534 @item @code{config-file} (default: @code{(tailon-configuration-file)})
23535 The configuration file to use for Tailon. This can be set to a
23536 @dfn{tailon-configuration-file} record value, or any gexp
23537 (@pxref{G-Expressions}).
23539 For example, to instead use a local file, the @code{local-file} function
23543 (service tailon-service-type
23544 (tailon-configuration
23545 (config-file (local-file "./my-tailon.conf"))))
23548 @item @code{package} (default: @code{tailon})
23549 The tailon package to use.
23554 @deftp {Data Type} tailon-configuration-file
23555 Data type representing the configuration options for Tailon.
23556 This type has the following parameters:
23559 @item @code{files} (default: @code{(list "/var/log")})
23560 List of files to display. The list can include strings for a single file
23561 or directory, or a list, where the first item is the name of a
23562 subsection, and the remaining items are the files or directories in that
23565 @item @code{bind} (default: @code{"localhost:8080"})
23566 Address and port to which Tailon should bind on.
23568 @item @code{relative-root} (default: @code{#f})
23569 URL path to use for Tailon, set to @code{#f} to not use a path.
23571 @item @code{allow-transfers?} (default: @code{#t})
23572 Allow downloading the log files in the web interface.
23574 @item @code{follow-names?} (default: @code{#t})
23575 Allow tailing of not-yet existent files.
23577 @item @code{tail-lines} (default: @code{200})
23578 Number of lines to read initially from each file.
23580 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
23581 Commands to allow running. By default, @code{sed} is disabled.
23583 @item @code{debug?} (default: @code{#f})
23584 Set @code{debug?} to @code{#t} to show debug messages.
23586 @item @code{wrap-lines} (default: @code{#t})
23587 Initial line wrapping state in the web interface. Set to @code{#t} to
23588 initially wrap lines (the default), or to @code{#f} to initially not
23591 @item @code{http-auth} (default: @code{#f})
23592 HTTP authentication type to use. Set to @code{#f} to disable
23593 authentication (the default). Supported values are @code{"digest"} or
23596 @item @code{users} (default: @code{#f})
23597 If HTTP authentication is enabled (see @code{http-auth}), access will be
23598 restricted to the credentials provided here. To configure users, use a
23599 list of pairs, where the first element of the pair is the username, and
23600 the 2nd element of the pair is the password.
23603 (tailon-configuration-file
23604 (http-auth "basic")
23605 (users '(("user1" . "password1")
23606 ("user2" . "password2"))))
23613 @subsubheading Darkstat Service
23615 Darkstat is a packet sniffer that captures network traffic, calculates
23616 statistics about usage, and serves reports over HTTP.
23618 @defvar {Scheme Variable} darkstat-service-type
23619 This is the service type for the
23620 @uref{https://unix4lyfe.org/darkstat/, darkstat}
23621 service, its value must be a @code{darkstat-configuration} record as in
23625 (service darkstat-service-type
23626 (darkstat-configuration
23627 (interface "eno1")))
23631 @deftp {Data Type} darkstat-configuration
23632 Data type representing the configuration of @command{darkstat}.
23635 @item @code{package} (default: @code{darkstat})
23636 The darkstat package to use.
23638 @item @code{interface}
23639 Capture traffic on the specified network interface.
23641 @item @code{port} (default: @code{"667"})
23642 Bind the web interface to the specified port.
23644 @item @code{bind-address} (default: @code{"127.0.0.1"})
23645 Bind the web interface to the specified address.
23647 @item @code{base} (default: @code{"/"})
23648 Specify the path of the base URL@. This can be useful if
23649 @command{darkstat} is accessed via a reverse proxy.
23654 @subsubheading Prometheus Node Exporter Service
23656 @cindex prometheus-node-exporter
23657 The Prometheus ``node exporter'' makes hardware and operating system statistics
23658 provided by the Linux kernel available for the Prometheus monitoring system.
23659 This service should be deployed on all physical nodes and virtual machines,
23660 where monitoring these statistics is desirable.
23662 @defvar {Scheme variable} prometheus-node-exporter-service-type
23663 This is the service type for the
23664 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
23665 service, its value must be a @code{prometheus-node-exporter-configuration}.
23668 (service prometheus-node-exporter-service-type)
23672 @deftp {Data Type} prometheus-node-exporter-configuration
23673 Data type representing the configuration of @command{node_exporter}.
23676 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
23677 The prometheus-node-exporter package to use.
23679 @item @code{web-listen-address} (default: @code{":9100"})
23680 Bind the web interface to the specified address.
23682 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
23683 This directory can be used to export metrics specific to this machine.
23684 Files containing metrics in the text format, with the filename ending in
23685 @code{.prom} should be placed in this directory.
23687 @item @code{extra-options} (default: @code{'()})
23688 Extra options to pass to the Prometheus node exporter.
23693 @subsubheading Zabbix server
23694 @cindex zabbix zabbix-server
23695 Zabbix provides monitoring metrics, among others network utilization, CPU load
23696 and disk space consumption:
23699 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
23700 @item Auto-discovery of servers and network devices and interfaces.
23701 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
23702 @item Distributed monitoring with centralized web administration.
23703 @item Native high performance agents.
23704 @item SLA, and ITIL KPI metrics on reporting.
23705 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
23706 @item Remote command execution through Zabbix proxies.
23709 @c %start of fragment
23711 Available @code{zabbix-server-configuration} fields are:
23713 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
23714 The zabbix-server package.
23718 @deftypevr {@code{zabbix-server-configuration} parameter} string user
23719 User who will run the Zabbix server.
23721 Defaults to @samp{"zabbix"}.
23725 @deftypevr {@code{zabbix-server-configuration} parameter} group group
23726 Group who will run the Zabbix server.
23728 Defaults to @samp{"zabbix"}.
23732 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
23733 Database host name.
23735 Defaults to @samp{"127.0.0.1"}.
23739 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
23742 Defaults to @samp{"zabbix"}.
23746 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
23749 Defaults to @samp{"zabbix"}.
23753 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
23754 Database password. Please, use @code{include-files} with
23755 @code{DBPassword=SECRET} inside a specified file instead.
23757 Defaults to @samp{""}.
23761 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
23764 Defaults to @samp{5432}.
23768 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
23769 Specifies where log messages are written to:
23773 @code{system} - syslog.
23776 @code{file} - file specified with @code{log-file} parameter.
23779 @code{console} - standard output.
23783 Defaults to @samp{""}.
23787 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
23788 Log file name for @code{log-type} @code{file} parameter.
23790 Defaults to @samp{"/var/log/zabbix/server.log"}.
23794 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
23797 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
23801 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
23802 The location of certificate authority (CA) files for SSL server
23803 certificate verification.
23805 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
23809 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
23810 Location of SSL client certificates.
23812 Defaults to @samp{"/etc/ssl/certs"}.
23816 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
23817 Extra options will be appended to Zabbix server configuration file.
23819 Defaults to @samp{""}.
23823 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
23824 You may include individual files or all files in a directory in the
23825 configuration file.
23827 Defaults to @samp{()}.
23831 @c %end of fragment
23833 @subsubheading Zabbix agent
23834 @cindex zabbix zabbix-agent
23836 Zabbix agent gathers information for Zabbix server.
23838 @c %start of fragment
23840 Available @code{zabbix-agent-configuration} fields are:
23842 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
23843 The zabbix-agent package.
23847 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
23848 User who will run the Zabbix agent.
23850 Defaults to @samp{"zabbix"}.
23854 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
23855 Group who will run the Zabbix agent.
23857 Defaults to @samp{"zabbix"}.
23861 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
23862 Unique, case sensitive hostname which is required for active checks and
23863 must match hostname as configured on the server.
23865 Defaults to @samp{""}.
23869 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
23870 Specifies where log messages are written to:
23874 @code{system} - syslog.
23877 @code{file} - file specified with @code{log-file} parameter.
23880 @code{console} - standard output.
23884 Defaults to @samp{""}.
23888 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
23889 Log file name for @code{log-type} @code{file} parameter.
23891 Defaults to @samp{"/var/log/zabbix/agent.log"}.
23895 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
23898 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
23902 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
23903 List of IP addresses, optionally in CIDR notation, or hostnames of
23904 Zabbix servers and Zabbix proxies. Incoming connections will be
23905 accepted only from the hosts listed here.
23907 Defaults to @samp{("127.0.0.1")}.
23911 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
23912 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
23913 proxies for active checks. If port is not specified, default port is
23914 used. If this parameter is not specified, active checks are disabled.
23916 Defaults to @samp{("127.0.0.1")}.
23920 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
23921 Extra options will be appended to Zabbix server configuration file.
23923 Defaults to @samp{""}.
23927 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
23928 You may include individual files or all files in a directory in the
23929 configuration file.
23931 Defaults to @samp{()}.
23935 @c %end of fragment
23937 @subsubheading Zabbix front-end
23938 @cindex zabbix zabbix-front-end
23940 This service provides a WEB interface to Zabbix server.
23942 @c %start of fragment
23944 Available @code{zabbix-front-end-configuration} fields are:
23946 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
23947 NGINX configuration.
23951 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
23952 Database host name.
23954 Defaults to @samp{"localhost"}.
23958 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
23961 Defaults to @samp{5432}.
23965 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
23968 Defaults to @samp{"zabbix"}.
23972 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
23975 Defaults to @samp{"zabbix"}.
23979 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
23980 Database password. Please, use @code{db-secret-file} instead.
23982 Defaults to @samp{""}.
23986 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
23987 Secret file containing the credentials for the Zabbix front-end. The value
23988 must be a local file name, not a G-expression. You are expected to create
23989 this file manually. Its contents will be copied into @file{zabbix.conf.php}
23990 as the value of @code{$DB['PASSWORD']}.
23992 Defaults to @samp{""}.
23996 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
23997 Zabbix server hostname.
23999 Defaults to @samp{"localhost"}.
24003 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
24004 Zabbix server port.
24006 Defaults to @samp{10051}.
24011 @c %end of fragment
24013 @node Kerberos Services
24014 @subsection Kerberos Services
24017 The @code{(gnu services kerberos)} module provides services relating to
24018 the authentication protocol @dfn{Kerberos}.
24020 @subsubheading Krb5 Service
24022 Programs using a Kerberos client library normally
24023 expect a configuration file in @file{/etc/krb5.conf}.
24024 This service generates such a file from a definition provided in the
24025 operating system declaration.
24026 It does not cause any daemon to be started.
24028 No ``keytab'' files are provided by this service---you must explicitly create them.
24029 This service is known to work with the MIT client library, @code{mit-krb5}.
24030 Other implementations have not been tested.
24032 @defvr {Scheme Variable} krb5-service-type
24033 A service type for Kerberos 5 clients.
24037 Here is an example of its use:
24039 (service krb5-service-type
24040 (krb5-configuration
24041 (default-realm "EXAMPLE.COM")
24042 (allow-weak-crypto? #t)
24045 (name "EXAMPLE.COM")
24046 (admin-server "groucho.example.com")
24047 (kdc "karl.example.com"))
24050 (admin-server "kerb-admin.argrx.edu")
24051 (kdc "keys.argrx.edu"))))))
24055 This example provides a Kerberos@tie{}5 client configuration which:
24057 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
24058 of which have distinct administration servers and key distribution centers;
24059 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
24060 specified by clients;
24061 @item Accepts services which only support encryption types known to be weak.
24064 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
24065 Only the most commonly used ones are described here.
24066 For a full list, and more detailed explanation of each, see the MIT
24067 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
24071 @deftp {Data Type} krb5-realm
24072 @cindex realm, kerberos
24075 This field is a string identifying the name of the realm.
24076 A common convention is to use the fully qualified DNS name of your organization,
24077 converted to upper case.
24079 @item @code{admin-server}
24080 This field is a string identifying the host where the administration server is
24084 This field is a string identifying the key distribution center
24089 @deftp {Data Type} krb5-configuration
24092 @item @code{allow-weak-crypto?} (default: @code{#f})
24093 If this flag is @code{#t} then services which only offer encryption algorithms
24094 known to be weak will be accepted.
24096 @item @code{default-realm} (default: @code{#f})
24097 This field should be a string identifying the default Kerberos
24098 realm for the client.
24099 You should set this field to the name of your Kerberos realm.
24100 If this value is @code{#f}
24101 then a realm must be specified with every Kerberos principal when invoking programs
24102 such as @command{kinit}.
24104 @item @code{realms}
24105 This should be a non-empty list of @code{krb5-realm} objects, which clients may
24107 Normally, one of them will have a @code{name} field matching the @code{default-realm}
24113 @subsubheading PAM krb5 Service
24116 The @code{pam-krb5} service allows for login authentication and password
24117 management via Kerberos.
24118 You will need this service if you want PAM enabled applications to authenticate
24119 users using Kerberos.
24121 @defvr {Scheme Variable} pam-krb5-service-type
24122 A service type for the Kerberos 5 PAM module.
24125 @deftp {Data Type} pam-krb5-configuration
24126 Data type representing the configuration of the Kerberos 5 PAM module.
24127 This type has the following parameters:
24129 @item @code{pam-krb5} (default: @code{pam-krb5})
24130 The pam-krb5 package to use.
24132 @item @code{minimum-uid} (default: @code{1000})
24133 The smallest user ID for which Kerberos authentications should be attempted.
24134 Local accounts with lower values will silently fail to authenticate.
24139 @node LDAP Services
24140 @subsection LDAP Services
24142 @cindex nslcd, LDAP service
24144 The @code{(gnu services authentication)} module provides the
24145 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
24146 server. In addition to configuring the service itself, you may want to add
24147 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
24148 Switch} for detailed information.
24150 Here is a simple operating system declaration with a default configuration of
24151 the @code{nslcd-service-type} and a Name Service Switch configuration that
24152 consults the @code{ldap} name service last:
24155 (use-service-modules authentication)
24156 (use-modules (gnu system nss))
24162 (service nslcd-service-type)
24163 (service dhcp-client-service-type)
24165 (name-service-switch
24166 (let ((services (list (name-service (name "db"))
24167 (name-service (name "files"))
24168 (name-service (name "ldap")))))
24169 (name-service-switch
24170 (inherit %mdns-host-lookup-nss)
24171 (password services)
24174 (netgroup services)
24175 (gshadow services)))))
24178 @c %start of generated documentation for nslcd-configuration
24180 Available @code{nslcd-configuration} fields are:
24182 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
24183 The @code{nss-pam-ldapd} package to use.
24187 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
24188 The number of threads to start that can handle requests and perform LDAP
24189 queries. Each thread opens a separate connection to the LDAP server.
24190 The default is to start 5 threads.
24192 Defaults to @samp{disabled}.
24196 @deftypevr {@code{nslcd-configuration} parameter} string uid
24197 This specifies the user id with which the daemon should be run.
24199 Defaults to @samp{"nslcd"}.
24203 @deftypevr {@code{nslcd-configuration} parameter} string gid
24204 This specifies the group id with which the daemon should be run.
24206 Defaults to @samp{"nslcd"}.
24210 @deftypevr {@code{nslcd-configuration} parameter} log-option log
24211 This option controls the way logging is done via a list containing
24212 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
24213 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
24214 argument is optional and specifies the log level. The log level may be
24215 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
24216 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
24217 specified log level or higher are logged.
24219 Defaults to @samp{("/var/log/nslcd" info)}.
24223 @deftypevr {@code{nslcd-configuration} parameter} list uri
24224 The list of LDAP server URIs. Normally, only the first server will be
24225 used with the following servers as fall-back.
24227 Defaults to @samp{("ldap://localhost:389/")}.
24231 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
24232 The version of the LDAP protocol to use. The default is to use the
24233 maximum version supported by the LDAP library.
24235 Defaults to @samp{disabled}.
24239 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
24240 Specifies the distinguished name with which to bind to the directory
24241 server for lookups. The default is to bind anonymously.
24243 Defaults to @samp{disabled}.
24247 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
24248 Specifies the credentials with which to bind. This option is only
24249 applicable when used with binddn.
24251 Defaults to @samp{disabled}.
24255 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
24256 Specifies the distinguished name to use when the root user tries to
24257 modify a user's password using the PAM module.
24259 Defaults to @samp{disabled}.
24263 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
24264 Specifies the credentials with which to bind if the root user tries to
24265 change a user's password. This option is only applicable when used with
24268 Defaults to @samp{disabled}.
24272 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
24273 Specifies the SASL mechanism to be used when performing SASL
24276 Defaults to @samp{disabled}.
24280 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
24281 Specifies the SASL realm to be used when performing SASL authentication.
24283 Defaults to @samp{disabled}.
24287 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
24288 Specifies the authentication identity to be used when performing SASL
24291 Defaults to @samp{disabled}.
24295 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
24296 Specifies the authorization identity to be used when performing SASL
24299 Defaults to @samp{disabled}.
24303 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
24304 Determines whether the LDAP server host name should be canonicalised. If
24305 this is enabled the LDAP library will do a reverse host name lookup. By
24306 default, it is left up to the LDAP library whether this check is
24309 Defaults to @samp{disabled}.
24313 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
24314 Set the name for the GSS-API Kerberos credentials cache.
24316 Defaults to @samp{disabled}.
24320 @deftypevr {@code{nslcd-configuration} parameter} string base
24321 The directory search base.
24323 Defaults to @samp{"dc=example,dc=com"}.
24327 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
24328 Specifies the search scope (subtree, onelevel, base or children). The
24329 default scope is subtree; base scope is almost never useful for name
24330 service lookups; children scope is not supported on all servers.
24332 Defaults to @samp{(subtree)}.
24336 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
24337 Specifies the policy for dereferencing aliases. The default policy is
24338 to never dereference aliases.
24340 Defaults to @samp{disabled}.
24344 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
24345 Specifies whether automatic referral chasing should be enabled. The
24346 default behaviour is to chase referrals.
24348 Defaults to @samp{disabled}.
24352 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
24353 This option allows for custom attributes to be looked up instead of the
24354 default RFC 2307 attributes. It is a list of maps, each consisting of
24355 the name of a map, the RFC 2307 attribute to match and the query
24356 expression for the attribute as it is available in the directory.
24358 Defaults to @samp{()}.
24362 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
24363 A list of filters consisting of the name of a map to which the filter
24364 applies and an LDAP search filter expression.
24366 Defaults to @samp{()}.
24370 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
24371 Specifies the time limit in seconds to use when connecting to the
24372 directory server. The default value is 10 seconds.
24374 Defaults to @samp{disabled}.
24378 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
24379 Specifies the time limit (in seconds) to wait for a response from the
24380 LDAP server. A value of zero, which is the default, is to wait
24381 indefinitely for searches to be completed.
24383 Defaults to @samp{disabled}.
24387 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
24388 Specifies the period if inactivity (in seconds) after which the con‐
24389 nection to the LDAP server will be closed. The default is not to time
24392 Defaults to @samp{disabled}.
24396 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
24397 Specifies the number of seconds to sleep when connecting to all LDAP
24398 servers fails. By default one second is waited between the first
24399 failure and the first retry.
24401 Defaults to @samp{disabled}.
24405 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
24406 Specifies the time after which the LDAP server is considered to be
24407 permanently unavailable. Once this time is reached retries will be done
24408 only once per this time period. The default value is 10 seconds.
24410 Defaults to @samp{disabled}.
24414 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
24415 Specifies whether to use SSL/TLS or not (the default is not to). If
24416 'start-tls is specified then StartTLS is used rather than raw LDAP over
24419 Defaults to @samp{disabled}.
24423 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
24424 Specifies what checks to perform on a server-supplied certificate. The
24425 meaning of the values is described in the ldap.conf(5) manual page.
24427 Defaults to @samp{disabled}.
24431 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
24432 Specifies the directory containing X.509 certificates for peer authen‐
24433 tication. This parameter is ignored when using GnuTLS.
24435 Defaults to @samp{disabled}.
24439 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
24440 Specifies the path to the X.509 certificate for peer authentication.
24442 Defaults to @samp{disabled}.
24446 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
24447 Specifies the path to an entropy source. This parameter is ignored when
24450 Defaults to @samp{disabled}.
24454 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
24455 Specifies the ciphers to use for TLS as a string.
24457 Defaults to @samp{disabled}.
24461 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
24462 Specifies the path to the file containing the local certificate for
24463 client TLS authentication.
24465 Defaults to @samp{disabled}.
24469 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
24470 Specifies the path to the file containing the private key for client TLS
24473 Defaults to @samp{disabled}.
24477 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
24478 Set this to a number greater than 0 to request paged results from the
24479 LDAP server in accordance with RFC2696. The default (0) is to not
24480 request paged results.
24482 Defaults to @samp{disabled}.
24486 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
24487 This option prevents group membership lookups through LDAP for the
24488 specified users. Alternatively, the value 'all-local may be used. With
24489 that value nslcd builds a full list of non-LDAP users on startup.
24491 Defaults to @samp{disabled}.
24495 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
24496 This option ensures that LDAP users with a numeric user id lower than
24497 the specified value are ignored.
24499 Defaults to @samp{disabled}.
24503 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
24504 This option specifies an offset that is added to all LDAP numeric user
24505 ids. This can be used to avoid user id collisions with local users.
24507 Defaults to @samp{disabled}.
24511 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
24512 This option specifies an offset that is added to all LDAP numeric group
24513 ids. This can be used to avoid user id collisions with local groups.
24515 Defaults to @samp{disabled}.
24519 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
24520 If this option is set, the member attribute of a group may point to
24521 another group. Members of nested groups are also returned in the higher
24522 level group and parent groups are returned when finding groups for a
24523 specific user. The default is not to perform extra searches for nested
24526 Defaults to @samp{disabled}.
24530 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
24531 If this option is set, the group member list is not retrieved when
24532 looking up groups. Lookups for finding which groups a user belongs to
24533 will remain functional so the user will likely still get the correct
24534 groups assigned on login.
24536 Defaults to @samp{disabled}.
24540 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
24541 If this option is set, functions which cause all user/group entries to
24542 be loaded from the directory will not succeed in doing so. This can
24543 dramatically reduce LDAP server load in situations where there are a
24544 great number of users and/or groups. This option is not recommended for
24545 most configurations.
24547 Defaults to @samp{disabled}.
24551 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
24552 This option can be used to specify how user and group names are verified
24553 within the system. This pattern is used to check all user and group
24554 names that are requested and returned from LDAP.
24556 Defaults to @samp{disabled}.
24560 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
24561 This specifies whether or not to perform searches using case-insensitive
24562 matching. Enabling this could open up the system to authorization
24563 bypass vulnerabilities and introduce nscd cache poisoning
24564 vulnerabilities which allow denial of service.
24566 Defaults to @samp{disabled}.
24570 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
24571 This option specifies whether password policy controls are requested and
24572 handled from the LDAP server when performing user authentication.
24574 Defaults to @samp{disabled}.
24578 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
24579 By default nslcd performs an LDAP search with the user's credentials
24580 after BIND (authentication) to ensure that the BIND operation was
24581 successful. The default search is a simple check to see if the user's
24582 DN exists. A search filter can be specified that will be used instead.
24583 It should return at least one entry.
24585 Defaults to @samp{disabled}.
24589 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
24590 This option allows flexible fine tuning of the authorisation check that
24591 should be performed. The search filter specified is executed and if any
24592 entries match, access is granted, otherwise access is denied.
24594 Defaults to @samp{disabled}.
24598 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
24599 If this option is set password modification using pam_ldap will be
24600 denied and the specified message will be presented to the user instead.
24601 The message can be used to direct the user to an alternative means of
24602 changing their password.
24604 Defaults to @samp{disabled}.
24608 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
24609 List of pam service names for which LDAP authentication should suffice.
24611 Defaults to @samp{()}.
24615 @c %end of generated documentation for nslcd-configuration
24619 @subsection Web Services
24624 The @code{(gnu services web)} module provides the Apache HTTP Server,
24625 the nginx web server, and also a fastcgi wrapper daemon.
24627 @subsubheading Apache HTTP Server
24629 @deffn {Scheme Variable} httpd-service-type
24630 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
24631 (@dfn{httpd}). The value for this service type is a
24632 @code{httpd-configuration} record.
24634 A simple example configuration is given below.
24637 (service httpd-service-type
24638 (httpd-configuration
24641 (server-name "www.example.com")
24642 (document-root "/srv/http/www.example.com")))))
24645 Other services can also extend the @code{httpd-service-type} to add to
24649 (simple-service 'www.example.com-server httpd-service-type
24653 (list (string-join '("ServerName www.example.com"
24654 "DocumentRoot /srv/http/www.example.com")
24659 The details for the @code{httpd-configuration}, @code{httpd-module},
24660 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
24663 @deffn {Data Type} httpd-configuration
24664 This data type represents the configuration for the httpd service.
24667 @item @code{package} (default: @code{httpd})
24668 The httpd package to use.
24670 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24671 The pid file used by the shepherd-service.
24673 @item @code{config} (default: @code{(httpd-config-file)})
24674 The configuration file to use with the httpd service. The default value
24675 is a @code{httpd-config-file} record, but this can also be a different
24676 G-expression that generates a file, for example a @code{plain-file}. A
24677 file outside of the store can also be specified through a string.
24682 @deffn {Data Type} httpd-module
24683 This data type represents a module for the httpd service.
24687 The name of the module.
24690 The file for the module. This can be relative to the httpd package being
24691 used, the absolute location of a file, or a G-expression for a file
24692 within the store, for example @code{(file-append mod-wsgi
24693 "/modules/mod_wsgi.so")}.
24698 @defvr {Scheme Variable} %default-httpd-modules
24699 A default list of @code{httpd-module} objects.
24702 @deffn {Data Type} httpd-config-file
24703 This data type represents a configuration file for the httpd service.
24706 @item @code{modules} (default: @code{%default-httpd-modules})
24707 The modules to load. Additional modules can be added here, or loaded by
24708 additional configuration.
24710 For example, in order to handle requests for PHP files, you can use Apache’s
24711 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
24714 (service httpd-service-type
24715 (httpd-configuration
24720 (name "proxy_module")
24721 (file "modules/mod_proxy.so"))
24723 (name "proxy_fcgi_module")
24724 (file "modules/mod_proxy_fcgi.so"))
24725 %default-httpd-modules))
24726 (extra-config (list "\
24727 <FilesMatch \\.php$>
24728 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
24729 </FilesMatch>"))))))
24730 (service php-fpm-service-type
24731 (php-fpm-configuration
24732 (socket "/var/run/php-fpm.sock")
24733 (socket-group "httpd")))
24736 @item @code{server-root} (default: @code{httpd})
24737 The @code{ServerRoot} in the configuration file, defaults to the httpd
24738 package. Directives including @code{Include} and @code{LoadModule} are
24739 taken as relative to the server root.
24741 @item @code{server-name} (default: @code{#f})
24742 The @code{ServerName} in the configuration file, used to specify the
24743 request scheme, hostname and port that the server uses to identify
24746 This doesn't need to be set in the server config, and can be specified
24747 in virtual hosts. The default is @code{#f} to not specify a
24750 @item @code{document-root} (default: @code{"/srv/http"})
24751 The @code{DocumentRoot} from which files will be served.
24753 @item @code{listen} (default: @code{'("80")})
24754 The list of values for the @code{Listen} directives in the config
24755 file. The value should be a list of strings, when each string can
24756 specify the port number to listen on, and optionally the IP address and
24759 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24760 The @code{PidFile} to use. This should match the @code{pid-file} set in
24761 the @code{httpd-configuration} so that the Shepherd service is
24762 configured correctly.
24764 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
24765 The @code{ErrorLog} to which the server will log errors.
24767 @item @code{user} (default: @code{"httpd"})
24768 The @code{User} which the server will answer requests as.
24770 @item @code{group} (default: @code{"httpd"})
24771 The @code{Group} which the server will answer requests as.
24773 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
24774 A flat list of strings and G-expressions which will be added to the end
24775 of the configuration file.
24777 Any values which the service is extended with will be appended to this
24783 @deffn {Data Type} httpd-virtualhost
24784 This data type represents a virtualhost configuration block for the httpd service.
24786 These should be added to the extra-config for the httpd-service.
24789 (simple-service 'www.example.com-server httpd-service-type
24793 (list (string-join '("ServerName www.example.com"
24794 "DocumentRoot /srv/http/www.example.com")
24799 @item @code{addresses-and-ports}
24800 The addresses and ports for the @code{VirtualHost} directive.
24802 @item @code{contents}
24803 The contents of the @code{VirtualHost} directive, this should be a list
24804 of strings and G-expressions.
24809 @subsubheading NGINX
24811 @deffn {Scheme Variable} nginx-service-type
24812 Service type for the @uref{https://nginx.org/,NGinx} web server. The
24813 value for this service type is a @code{<nginx-configuration>} record.
24815 A simple example configuration is given below.
24818 (service nginx-service-type
24819 (nginx-configuration
24821 (list (nginx-server-configuration
24822 (server-name '("www.example.com"))
24823 (root "/srv/http/www.example.com"))))))
24826 In addition to adding server blocks to the service configuration
24827 directly, this service can be extended by other services to add server
24828 blocks, as in this example:
24831 (simple-service 'my-extra-server nginx-service-type
24832 (list (nginx-server-configuration
24833 (root "/srv/http/extra-website")
24834 (try-files (list "$uri" "$uri/index.html")))))
24838 At startup, @command{nginx} has not yet read its configuration file, so
24839 it uses a default file to log error messages. If it fails to load its
24840 configuration file, that is where error messages are logged. After the
24841 configuration file is loaded, the default error log file changes as per
24842 configuration. In our case, startup error messages can be found in
24843 @file{/var/run/nginx/logs/error.log}, and after configuration in
24844 @file{/var/log/nginx/error.log}. The second location can be changed
24845 with the @var{log-directory} configuration option.
24847 @deffn {Data Type} nginx-configuration
24848 This data type represents the configuration for NGinx. Some
24849 configuration can be done through this and the other provided record
24850 types, or alternatively, a config file can be provided.
24853 @item @code{nginx} (default: @code{nginx})
24854 The nginx package to use.
24856 @item @code{log-directory} (default: @code{"/var/log/nginx"})
24857 The directory to which NGinx will write log files.
24859 @item @code{run-directory} (default: @code{"/var/run/nginx"})
24860 The directory in which NGinx will create a pid file, and write temporary
24863 @item @code{server-blocks} (default: @code{'()})
24864 A list of @dfn{server blocks} to create in the generated configuration
24865 file, the elements should be of type
24866 @code{<nginx-server-configuration>}.
24868 The following example would setup NGinx to serve @code{www.example.com}
24869 from the @code{/srv/http/www.example.com} directory, without using
24872 (service nginx-service-type
24873 (nginx-configuration
24875 (list (nginx-server-configuration
24876 (server-name '("www.example.com"))
24877 (root "/srv/http/www.example.com"))))))
24880 @item @code{upstream-blocks} (default: @code{'()})
24881 A list of @dfn{upstream blocks} to create in the generated configuration
24882 file, the elements should be of type
24883 @code{<nginx-upstream-configuration>}.
24885 Configuring upstreams through the @code{upstream-blocks} can be useful
24886 when combined with @code{locations} in the
24887 @code{<nginx-server-configuration>} records. The following example
24888 creates a server configuration with one location configuration, that
24889 will proxy requests to a upstream configuration, which will handle
24890 requests with two servers.
24895 (nginx-configuration
24897 (list (nginx-server-configuration
24898 (server-name '("www.example.com"))
24899 (root "/srv/http/www.example.com")
24902 (nginx-location-configuration
24904 (body '("proxy_pass http://server-proxy;"))))))))
24906 (list (nginx-upstream-configuration
24907 (name "server-proxy")
24908 (servers (list "server1.example.com"
24909 "server2.example.com")))))))
24912 @item @code{file} (default: @code{#f})
24913 If a configuration @var{file} is provided, this will be used, rather than
24914 generating a configuration file from the provided @code{log-directory},
24915 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
24916 proper operation, these arguments should match what is in @var{file} to ensure
24917 that the directories are created when the service is activated.
24919 This can be useful if you have an existing configuration file, or it's
24920 not possible to do what is required through the other parts of the
24921 nginx-configuration record.
24923 @item @code{server-names-hash-bucket-size} (default: @code{#f})
24924 Bucket size for the server names hash tables, defaults to @code{#f} to
24925 use the size of the processors cache line.
24927 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
24928 Maximum bucket size for the server names hash tables.
24930 @item @code{modules} (default: @code{'()})
24931 List of nginx dynamic modules to load. This should be a list of file
24932 names of loadable modules, as in this example:
24937 (file-append nginx-accept-language-module "\
24938 /etc/nginx/modules/ngx_http_accept_language_module.so")
24939 (file-append nginx-lua-module "\
24940 /etc/nginx/modules/ngx_http_lua_module.so")))
24943 @item @code{lua-package-path} (default: @code{'()})
24944 List of nginx lua packages to load. This should be a list of package
24945 names of loadable lua modules, as in this example:
24948 (lua-package-path (list lua-resty-core
24955 @item @code{lua-package-cpath} (default: @code{'()})
24956 List of nginx lua C packages to load. This should be a list of package
24957 names of loadable lua C modules, as in this example:
24960 (lua-package-cpath (list lua-resty-signal))
24963 @item @code{global-directives} (default: @code{'((events . ()))})
24964 Association list of global directives for the top level of the nginx
24965 configuration. Values may themselves be association lists.
24969 `((worker_processes . 16)
24971 (events . ((worker_connections . 1024)))))
24974 @item @code{extra-content} (default: @code{""})
24975 Extra content for the @code{http} block. Should be string or a string
24976 valued G-expression.
24981 @deftp {Data Type} nginx-server-configuration
24982 Data type representing the configuration of an nginx server block.
24983 This type has the following parameters:
24986 @item @code{listen} (default: @code{'("80" "443 ssl")})
24987 Each @code{listen} directive sets the address and port for IP, or the
24988 path for a UNIX-domain socket on which the server will accept requests.
24989 Both address and port, or only address or only port can be specified.
24990 An address may also be a hostname, for example:
24993 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
24996 @item @code{server-name} (default: @code{(list 'default)})
24997 A list of server names this server represents. @code{'default} represents the
24998 default server for connections matching no other server.
25000 @item @code{root} (default: @code{"/srv/http"})
25001 Root of the website nginx will serve.
25003 @item @code{locations} (default: @code{'()})
25004 A list of @dfn{nginx-location-configuration} or
25005 @dfn{nginx-named-location-configuration} records to use within this
25008 @item @code{index} (default: @code{(list "index.html")})
25009 Index files to look for when clients ask for a directory. If it cannot be found,
25010 Nginx will send the list of files in the directory.
25012 @item @code{try-files} (default: @code{'()})
25013 A list of files whose existence is checked in the specified order.
25014 @code{nginx} will use the first file it finds to process the request.
25016 @item @code{ssl-certificate} (default: @code{#f})
25017 Where to find the certificate for secure connections. Set it to @code{#f} if
25018 you don't have a certificate or you don't want to use HTTPS.
25020 @item @code{ssl-certificate-key} (default: @code{#f})
25021 Where to find the private key for secure connections. Set it to @code{#f} if
25022 you don't have a key or you don't want to use HTTPS.
25024 @item @code{server-tokens?} (default: @code{#f})
25025 Whether the server should add its configuration to response.
25027 @item @code{raw-content} (default: @code{'()})
25028 A list of raw lines added to the server block.
25033 @deftp {Data Type} nginx-upstream-configuration
25034 Data type representing the configuration of an nginx @code{upstream}
25035 block. This type has the following parameters:
25039 Name for this group of servers.
25041 @item @code{servers}
25042 Specify the addresses of the servers in the group. The address can be
25043 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
25044 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
25045 prefix @samp{unix:}. For addresses using an IP address or domain name,
25046 the default port is 80, and a different port can be specified
25052 @deftp {Data Type} nginx-location-configuration
25053 Data type representing the configuration of an nginx @code{location}
25054 block. This type has the following parameters:
25058 URI which this location block matches.
25060 @anchor{nginx-location-configuration body}
25062 Body of the location block, specified as a list of strings. This can contain
25064 configuration directives. For example, to pass requests to a upstream
25065 server group defined using an @code{nginx-upstream-configuration} block,
25066 the following directive would be specified in the body @samp{(list "proxy_pass
25067 http://upstream-name;")}.
25072 @deftp {Data Type} nginx-named-location-configuration
25073 Data type representing the configuration of an nginx named location
25074 block. Named location blocks are used for request redirection, and not
25075 used for regular request processing. This type has the following
25080 Name to identify this location block.
25083 @xref{nginx-location-configuration body}, as the body for named location
25084 blocks can be used in a similar way to the
25085 @code{nginx-location-configuration body}. One restriction is that the
25086 body of a named location block cannot contain location blocks.
25091 @subsubheading Varnish Cache
25093 Varnish is a fast cache server that sits in between web applications
25094 and end users. It proxies requests from clients and caches the
25095 accessed URLs such that multiple requests for the same resource only
25096 creates one request to the back-end.
25098 @defvr {Scheme Variable} varnish-service-type
25099 Service type for the Varnish daemon.
25102 @deftp {Data Type} varnish-configuration
25103 Data type representing the @code{varnish} service configuration.
25104 This type has the following parameters:
25107 @item @code{package} (default: @code{varnish})
25108 The Varnish package to use.
25110 @item @code{name} (default: @code{"default"})
25111 A name for this Varnish instance. Varnish will create a directory in
25112 @file{/var/varnish/} with this name and keep temporary files there. If
25113 the name starts with a forward slash, it is interpreted as an absolute
25116 Pass the @code{-n} argument to other Varnish programs to connect to the
25117 named instance, e.g.@: @command{varnishncsa -n default}.
25119 @item @code{backend} (default: @code{"localhost:8080"})
25120 The backend to use. This option has no effect if @code{vcl} is set.
25122 @item @code{vcl} (default: #f)
25123 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
25124 is @code{#f}, Varnish will proxy @code{backend} using the default
25125 configuration. Otherwise this must be a file-like object with valid
25128 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
25129 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
25130 can do something along these lines:
25133 (define %gnu-mirror
25134 (plain-file "gnu.vcl"
25136 backend gnu @{ .host = \"www.gnu.org\"; @}"))
25140 (services (cons (service varnish-service-type
25141 (varnish-configuration
25143 (vcl %gnu-mirror)))
25147 The configuration of an already running Varnish instance can be inspected
25148 and changed using the @command{varnishadm} program.
25150 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
25151 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
25152 comprehensive documentation on Varnish and its configuration language.
25154 @item @code{listen} (default: @code{'("localhost:80")})
25155 List of addresses Varnish will listen on.
25157 @item @code{storage} (default: @code{'("malloc,128m")})
25158 List of storage backends that will be available in VCL.
25160 @item @code{parameters} (default: @code{'()})
25161 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
25163 @item @code{extra-options} (default: @code{'()})
25164 Additional arguments to pass to the @command{varnishd} process.
25169 @subsubheading Patchwork
25171 Patchwork is a patch tracking system. It can collect patches sent to a
25172 mailing list, and display them in a web interface.
25174 @defvr {Scheme Variable} patchwork-service-type
25175 Service type for Patchwork.
25178 The following example is an example of a minimal service for Patchwork, for
25179 the @code{patchwork.example.com} domain.
25182 (service patchwork-service-type
25183 (patchwork-configuration
25184 (domain "patchwork.example.com")
25186 (patchwork-settings-module
25187 (allowed-hosts (list domain))
25188 (default-from-email "patchwork@@patchwork.example.com")))
25189 (getmail-retriever-config
25190 (getmail-retriever-configuration
25191 (type "SimpleIMAPSSLRetriever")
25192 (server "imap.example.com")
25194 (username "patchwork")
25196 (list (file-append coreutils "/bin/cat")
25197 "/etc/getmail-patchwork-imap-password"))
25199 '((mailboxes . ("Patches"))))))))
25203 There are three records for configuring the Patchwork service. The
25204 @code{<patchwork-configuration>} relates to the configuration for Patchwork
25205 within the HTTPD service.
25207 The @code{settings-module} field within the @code{<patchwork-configuration>}
25208 record can be populated with the @code{<patchwork-settings-module>} record,
25209 which describes a settings module that is generated within the Guix store.
25211 For the @code{database-configuration} field within the
25212 @code{<patchwork-settings-module>}, the
25213 @code{<patchwork-database-configuration>} must be used.
25215 @deftp {Data Type} patchwork-configuration
25216 Data type representing the Patchwork service configuration. This type has the
25217 following parameters:
25220 @item @code{patchwork} (default: @code{patchwork})
25221 The Patchwork package to use.
25223 @item @code{domain}
25224 The domain to use for Patchwork, this is used in the HTTPD service virtual
25227 @item @code{settings-module}
25228 The settings module to use for Patchwork. As a Django application, Patchwork
25229 is configured with a Python module containing the settings. This can either be
25230 an instance of the @code{<patchwork-settings-module>} record, any other record
25231 that represents the settings in the store, or a directory outside of the
25234 @item @code{static-path} (default: @code{"/static/"})
25235 The path under which the HTTPD service should serve the static files.
25237 @item @code{getmail-retriever-config}
25238 The getmail-retriever-configuration record value to use with
25239 Patchwork. Getmail will be configured with this value, the messages will be
25240 delivered to Patchwork.
25245 @deftp {Data Type} patchwork-settings-module
25246 Data type representing a settings module for Patchwork. Some of these
25247 settings relate directly to Patchwork, but others relate to Django, the web
25248 framework used by Patchwork, or the Django Rest Framework library. This type
25249 has the following parameters:
25252 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
25253 The database connection settings used for Patchwork. See the
25254 @code{<patchwork-database-configuration>} record type for more information.
25256 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
25257 Patchwork, as a Django web application uses a secret key for cryptographically
25258 signing values. This file should contain a unique unpredictable value.
25260 If this file does not exist, it will be created and populated with a random
25261 value by the patchwork-setup shepherd service.
25263 This setting relates to Django.
25265 @item @code{allowed-hosts}
25266 A list of valid hosts for this Patchwork service. This should at least include
25267 the domain specified in the @code{<patchwork-configuration>} record.
25269 This is a Django setting.
25271 @item @code{default-from-email}
25272 The email address from which Patchwork should send email by default.
25274 This is a Patchwork setting.
25276 @item @code{static-url} (default: @code{#f})
25277 The URL to use when serving static assets. It can be part of a URL, or a full
25278 URL, but must end in a @code{/}.
25280 If the default value is used, the @code{static-path} value from the
25281 @code{<patchwork-configuration>} record will be used.
25283 This is a Django setting.
25285 @item @code{admins} (default: @code{'()})
25286 Email addresses to send the details of errors that occur. Each value should
25287 be a list containing two elements, the name and then the email address.
25289 This is a Django setting.
25291 @item @code{debug?} (default: @code{#f})
25292 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
25293 messages will be shown.
25295 This is a Django setting.
25297 @item @code{enable-rest-api?} (default: @code{#t})
25298 Whether to enable the Patchwork REST API.
25300 This is a Patchwork setting.
25302 @item @code{enable-xmlrpc?} (default: @code{#t})
25303 Whether to enable the XML RPC API.
25305 This is a Patchwork setting.
25307 @item @code{force-https-links?} (default: @code{#t})
25308 Whether to use HTTPS links on Patchwork pages.
25310 This is a Patchwork setting.
25312 @item @code{extra-settings} (default: @code{""})
25313 Extra code to place at the end of the Patchwork settings module.
25318 @deftp {Data Type} patchwork-database-configuration
25319 Data type representing the database configuration for Patchwork.
25322 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
25323 The database engine to use.
25325 @item @code{name} (default: @code{"patchwork"})
25326 The name of the database to use.
25328 @item @code{user} (default: @code{"httpd"})
25329 The user to connect to the database as.
25331 @item @code{password} (default: @code{""})
25332 The password to use when connecting to the database.
25334 @item @code{host} (default: @code{""})
25335 The host to make the database connection to.
25337 @item @code{port} (default: @code{""})
25338 The port on which to connect to the database.
25343 @subsubheading Mumi
25345 @cindex Mumi, Debbugs Web interface
25346 @cindex Debbugs, Mumi Web interface
25347 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
25348 Web interface to the Debbugs bug tracker, by default for
25349 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
25350 but it also fetches and indexes mail retrieved from Debbugs.
25352 @defvr {Scheme Variable} mumi-service-type
25353 This is the service type for Mumi.
25356 @deftp {Data Type} mumi-configuration
25357 Data type representing the Mumi service configuration. This type has the
25361 @item @code{mumi} (default: @code{mumi})
25362 The Mumi package to use.
25364 @item @code{mailer?} (default: @code{#true})
25365 Whether to enable or disable the mailer component.
25367 @item @code{mumi-configuration-sender}
25368 The email address used as the sender for comments.
25370 @item @code{mumi-configuration-smtp}
25371 A URI to configure the SMTP settings for Mailutils. This could be
25372 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
25373 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
25374 mailutils, GNU@tie{}Mailutils}.
25380 @subsubheading FastCGI
25383 FastCGI is an interface between the front-end and the back-end of a web
25384 service. It is a somewhat legacy facility; new web services should
25385 generally just talk HTTP between the front-end and the back-end.
25386 However there are a number of back-end services such as PHP or the
25387 optimized HTTP Git repository access that use FastCGI, so we have
25388 support for it in Guix.
25390 To use FastCGI, you configure the front-end web server (e.g., nginx) to
25391 dispatch some subset of its requests to the fastcgi backend, which
25392 listens on a local TCP or UNIX socket. There is an intermediary
25393 @code{fcgiwrap} program that sits between the actual backend process and
25394 the web server. The front-end indicates which backend program to run,
25395 passing that information to the @code{fcgiwrap} process.
25397 @defvr {Scheme Variable} fcgiwrap-service-type
25398 A service type for the @code{fcgiwrap} FastCGI proxy.
25401 @deftp {Data Type} fcgiwrap-configuration
25402 Data type representing the configuration of the @code{fcgiwrap} service.
25403 This type has the following parameters:
25405 @item @code{package} (default: @code{fcgiwrap})
25406 The fcgiwrap package to use.
25408 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
25409 The socket on which the @code{fcgiwrap} process should listen, as a
25410 string. Valid @var{socket} values include
25411 @code{unix:@var{/path/to/unix/socket}},
25412 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
25413 @code{tcp6:[@var{ipv6_addr}]:port}.
25415 @item @code{user} (default: @code{fcgiwrap})
25416 @itemx @code{group} (default: @code{fcgiwrap})
25417 The user and group names, as strings, under which to run the
25418 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
25419 the user asks for the specific user or group names @code{fcgiwrap} that
25420 the corresponding user and/or group is present on the system.
25422 It is possible to configure a FastCGI-backed web service to pass HTTP
25423 authentication information from the front-end to the back-end, and to
25424 allow @code{fcgiwrap} to run the back-end process as a corresponding
25425 local user. To enable this capability on the back-end, run
25426 @code{fcgiwrap} as the @code{root} user and group. Note that this
25427 capability also has to be configured on the front-end as well.
25432 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
25433 with some additional features useful for sites of any size.
25435 These features include:
25437 @item Adaptive process spawning
25438 @item Basic statistics (similar to Apache's mod_status)
25439 @item Advanced process management with graceful stop/start
25440 @item Ability to start workers with different uid/gid/chroot/environment
25441 and different php.ini (replaces safe_mode)
25442 @item Stdout & stderr logging
25443 @item Emergency restart in case of accidental opcode cache destruction
25444 @item Accelerated upload support
25445 @item Support for a "slowlog"
25446 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
25447 a special function to finish request & flush all data while continuing to do
25448 something time-consuming (video converting, stats processing, etc.)
25450 ...@: and much more.
25452 @defvr {Scheme Variable} php-fpm-service-type
25453 A Service type for @code{php-fpm}.
25456 @deftp {Data Type} php-fpm-configuration
25457 Data Type for php-fpm service configuration.
25459 @item @code{php} (default: @code{php})
25460 The php package to use.
25461 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
25462 The address on which to accept FastCGI requests. Valid syntaxes are:
25464 @item @code{"ip.add.re.ss:port"}
25465 Listen on a TCP socket to a specific address on a specific port.
25466 @item @code{"port"}
25467 Listen on a TCP socket to all addresses on a specific port.
25468 @item @code{"/path/to/unix/socket"}
25469 Listen on a unix socket.
25472 @item @code{user} (default: @code{php-fpm})
25473 User who will own the php worker processes.
25474 @item @code{group} (default: @code{php-fpm})
25475 Group of the worker processes.
25476 @item @code{socket-user} (default: @code{php-fpm})
25477 User who can speak to the php-fpm socket.
25478 @item @code{socket-group} (default: @code{nginx})
25479 Group that can speak to the php-fpm socket.
25480 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
25481 The process id of the php-fpm process is written to this file
25482 once the service has started.
25483 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
25484 Log for the php-fpm master process.
25485 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
25486 Detailed settings for the php-fpm process manager.
25489 @item @code{<php-fpm-dynamic-process-manager-configuration>}
25490 @item @code{<php-fpm-static-process-manager-configuration>}
25491 @item @code{<php-fpm-on-demand-process-manager-configuration>}
25493 @item @code{display-errors} (default @code{#f})
25494 Determines whether php errors and warning should be sent to clients
25495 and displayed in their browsers.
25496 This is useful for local php development, but a security risk for public sites,
25497 as error messages can reveal passwords and personal data.
25498 @item @code{timezone} (default @code{#f})
25499 Specifies @code{php_admin_value[date.timezone]} parameter.
25500 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
25501 This file will log the @code{stderr} outputs of php worker processes.
25502 Can be set to @code{#f} to disable logging.
25503 @item @code{file} (default @code{#f})
25504 An optional override of the whole configuration.
25505 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25506 @item @code{php-ini-file} (default @code{#f})
25507 An optional override of the default php settings.
25508 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
25509 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25511 For local development it is useful to set a higher timeout and memory
25512 limit for spawned php processes. This be accomplished with the
25513 following operating system configuration snippet:
25515 (define %local-php-ini
25516 (plain-file "php.ini"
25518 max_execution_time = 1800"))
25522 (services (cons (service php-fpm-service-type
25523 (php-fpm-configuration
25524 (php-ini-file %local-php-ini)))
25528 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
25529 directives} for comprehensive documentation on the acceptable
25530 @file{php.ini} directives.
25534 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
25535 Data Type for the @code{dynamic} php-fpm process manager. With the
25536 @code{dynamic} process manager, spare worker processes are kept around
25537 based on its configured limits.
25539 @item @code{max-children} (default: @code{5})
25540 Maximum of worker processes.
25541 @item @code{start-servers} (default: @code{2})
25542 How many worker processes should be started on start-up.
25543 @item @code{min-spare-servers} (default: @code{1})
25544 How many spare worker processes should be kept around at minimum.
25545 @item @code{max-spare-servers} (default: @code{3})
25546 How many spare worker processes should be kept around at maximum.
25550 @deftp {Data type} php-fpm-static-process-manager-configuration
25551 Data Type for the @code{static} php-fpm process manager. With the
25552 @code{static} process manager, an unchanging number of worker processes
25555 @item @code{max-children} (default: @code{5})
25556 Maximum of worker processes.
25560 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
25561 Data Type for the @code{on-demand} php-fpm process manager. With the
25562 @code{on-demand} process manager, worker processes are only created as
25565 @item @code{max-children} (default: @code{5})
25566 Maximum of worker processes.
25567 @item @code{process-idle-timeout} (default: @code{10})
25568 The time in seconds after which a process with no requests is killed.
25573 @deffn {Scheme Procedure} nginx-php-location @
25574 [#:nginx-package nginx] @
25575 [socket (string-append "/var/run/php" @
25576 (version-major (package-version php)) @
25578 A helper function to quickly add php to an @code{nginx-server-configuration}.
25581 A simple services setup for nginx with php can look like this:
25583 (services (cons* (service dhcp-client-service-type)
25584 (service php-fpm-service-type)
25585 (service nginx-service-type
25586 (nginx-server-configuration
25587 (server-name '("example.com"))
25588 (root "/srv/http/")
25590 (list (nginx-php-location)))
25592 (ssl-certificate #f)
25593 (ssl-certificate-key #f)))
25597 @cindex cat-avatar-generator
25598 The cat avatar generator is a simple service to demonstrate the use of php-fpm
25599 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
25600 the hash of a user's email address.
25602 @deffn {Scheme Procedure} cat-avatar-generator-service @
25603 [#:cache-dir "/var/cache/cat-avatar-generator"] @
25604 [#:package cat-avatar-generator] @
25605 [#:configuration (nginx-server-configuration)]
25606 Returns an nginx-server-configuration that inherits @code{configuration}. It
25607 extends the nginx configuration to add a server block that serves @code{package},
25608 a version of cat-avatar-generator. During execution, cat-avatar-generator will
25609 be able to use @code{cache-dir} as its cache directory.
25612 A simple setup for cat-avatar-generator can look like this:
25614 (services (cons* (cat-avatar-generator-service
25616 (nginx-server-configuration
25617 (server-name '("example.com"))))
25622 @subsubheading Hpcguix-web
25624 @cindex hpcguix-web
25625 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
25626 program is a customizable web interface to browse Guix packages,
25627 initially designed for users of high-performance computing (HPC)
25630 @defvr {Scheme Variable} hpcguix-web-service-type
25631 The service type for @code{hpcguix-web}.
25634 @deftp {Data Type} hpcguix-web-configuration
25635 Data type for the hpcguix-web service configuration.
25639 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
25640 configuration. The main items available in this spec are:
25643 @item @code{title-prefix} (default: @code{"hpcguix | "})
25644 The page title prefix.
25646 @item @code{guix-command} (default: @code{"guix"})
25647 The @command{guix} command.
25649 @item @code{package-filter-proc} (default: @code{(const #t)})
25650 A procedure specifying how to filter packages that are displayed.
25652 @item @code{package-page-extension-proc} (default: @code{(const '())})
25653 Extension package for @code{hpcguix-web}.
25655 @item @code{menu} (default: @code{'()})
25656 Additional entry in page @code{menu}.
25658 @item @code{channels} (default: @code{%default-channels})
25659 List of channels from which the package list is built (@pxref{Channels}).
25661 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
25662 The expiration time, in seconds, after which the package list is rebuilt from
25663 the latest instances of the given channels.
25666 See the hpcguix-web repository for a
25667 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
25670 @item @code{package} (default: @code{hpcguix-web})
25671 The hpcguix-web package to use.
25675 A typical hpcguix-web service declaration looks like this:
25678 (service hpcguix-web-service-type
25679 (hpcguix-web-configuration
25681 #~(define site-config
25682 (hpcweb-configuration
25683 (title-prefix "Guix-HPC - ")
25684 (menu '(("/about" "ABOUT"))))))))
25688 The hpcguix-web service periodically updates the package list it publishes by
25689 pulling channels from Git. To that end, it needs to access X.509 certificates
25690 so that it can authenticate Git servers when communicating over HTTPS, and it
25691 assumes that @file{/etc/ssl/certs} contains those certificates.
25693 Thus, make sure to add @code{nss-certs} or another certificate package to the
25694 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
25695 more information on X.509 certificates.
25698 @subsubheading gmnisrv
25701 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
25702 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
25704 @deffn {Scheme Variable} gmnisrv-service-type
25705 This is the type of the gmnisrv service, whose value should be a
25706 @code{gmnisrv-configuration} object, as in this example:
25709 (service gmnisrv-service-type
25710 (gmnisrv-configuration
25711 (config-file (local-file "./my-gmnisrv.ini"))))
25715 @deftp {Data Type} gmnisrv-configuration
25716 Data type representing the configuration of gmnisrv.
25719 @item @code{package} (default: @var{gmnisrv})
25720 Package object of the gmnisrv server.
25722 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
25723 File-like object of the gmnisrv configuration file to use. The default
25724 configuration listens on port 1965 and serves files from
25725 @file{/srv/gemini}. Certificates are stored in
25726 @file{/var/lib/gemini/certs}. For more information, run @command{man
25727 gmnisrv} and @command{man gmnisrv.ini}.
25732 @subsubheading Agate
25735 The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
25736 (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
25737 program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
25738 protocol server written in Rust.
25740 @deffn {Scheme Variable} agate-service-type
25741 This is the type of the agate service, whose value should be an
25742 @code{agate-service-type} object, as in this example:
25745 (service agate-service-type
25746 (agate-configuration
25747 (content "/srv/gemini")
25748 (cert "/srv/cert.pem")
25749 (key "/srv/key.rsa")))
25752 The example above represents the minimal tweaking necessary to get Agate
25753 up and running. Specifying the path to the certificate and key is
25754 always necessary, as the Gemini protocol requires TLS by default.
25756 To obtain a certificate and a key, you could, for example, use OpenSSL,
25757 running a command similar to the following example:
25760 openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
25761 -days 3650 -nodes -subj "/CN=example.com"
25764 Of course, you'll have to replace @i{example.com} with your own domain
25765 name, and then point the Agate configuration towards the path of the
25766 generated key and certificate.
25770 @deftp {Data Type} agate-configuration
25771 Data type representing the configuration of Agate.
25774 @item @code{package} (default: @code{agate})
25775 The package object of the Agate server.
25777 @item @code{content} (default: @file{"/srv/gemini"})
25778 The directory from which Agate will serve files.
25780 @item @code{cert} (default: @code{#f})
25781 The path to the TLS certificate PEM file to be used for encrypted
25782 connections. Must be filled in with a value from the user.
25784 @item @code{key} (default: @code{#f})
25785 The path to the PKCS8 private key file to be used for encrypted
25786 connections. Must be filled in with a value from the user.
25788 @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
25789 A list of the addresses to listen on.
25791 @item @code{hostname} (default: @code{#f})
25792 The domain name of this Gemini server. Optional.
25794 @item @code{lang} (default: @code{#f})
25795 RFC 4646 language code(s) for text/gemini documents. Optional.
25797 @item @code{silent?} (default: @code{#f})
25798 Set to @code{#t} to disable logging output.
25800 @item @code{serve-secret?} (default: @code{#f})
25801 Set to @code{#t} to serve secret files (files/directories starting with
25804 @item @code{log-ip?} (default: @code{#t})
25805 Whether or not to output IP addresses when logging.
25807 @item @code{user} (default: @code{"agate"})
25808 Owner of the @code{agate} process.
25810 @item @code{group} (default: @code{"agate"})
25811 Owner's group of the @code{agate} process.
25813 @item @code{log-file} (default: @file{"/var/log/agate.log"})
25814 The file which should store the logging output of Agate.
25819 @node Certificate Services
25820 @subsection Certificate Services
25823 @cindex HTTP, HTTPS
25824 @cindex Let's Encrypt
25825 @cindex TLS certificates
25826 The @code{(gnu services certbot)} module provides a service to
25827 automatically obtain a valid TLS certificate from the Let's Encrypt
25828 certificate authority. These certificates can then be used to serve
25829 content securely over HTTPS or other TLS-based protocols, with the
25830 knowledge that the client will be able to verify the server's
25833 @url{https://letsencrypt.org/, Let's Encrypt} provides the
25834 @code{certbot} tool to automate the certification process. This tool
25835 first securely generates a key on the server. It then makes a request
25836 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
25837 checks that the request originates from the host in question by using a
25838 challenge-response protocol, requiring the server to provide its
25839 response over HTTP@. If that protocol completes successfully, the CA
25840 signs the key, resulting in a certificate. That certificate is valid
25841 for a limited period of time, and therefore to continue to provide TLS
25842 services, the server needs to periodically ask the CA to renew its
25845 The certbot service automates this process: the initial key
25846 generation, the initial certification request to the Let's Encrypt
25847 service, the web server challenge/response integration, writing the
25848 certificate to disk, the automated periodic renewals, and the deployment
25849 tasks associated with the renewal (e.g.@: reloading services, copying keys
25850 with different permissions).
25852 Certbot is run twice a day, at a random minute within the hour. It
25853 won't do anything until your certificates are due for renewal or
25854 revoked, but running it regularly would give your service a chance of
25855 staying online in case a Let's Encrypt-initiated revocation happened for
25858 By using this service, you agree to the ACME Subscriber Agreement, which
25859 can be found there:
25860 @url{https://acme-v01.api.letsencrypt.org/directory}.
25862 @defvr {Scheme Variable} certbot-service-type
25863 A service type for the @code{certbot} Let's Encrypt client. Its value
25864 must be a @code{certbot-configuration} record as in this example:
25867 (define %nginx-deploy-hook
25869 "nginx-deploy-hook"
25870 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
25871 (kill pid SIGHUP))))
25873 (service certbot-service-type
25874 (certbot-configuration
25875 (email "foo@@example.net")
25878 (certificate-configuration
25879 (domains '("example.net" "www.example.net"))
25880 (deploy-hook %nginx-deploy-hook))
25881 (certificate-configuration
25882 (domains '("bar.example.net")))))))
25885 See below for details about @code{certbot-configuration}.
25888 @deftp {Data Type} certbot-configuration
25889 Data type representing the configuration of the @code{certbot} service.
25890 This type has the following parameters:
25893 @item @code{package} (default: @code{certbot})
25894 The certbot package to use.
25896 @item @code{webroot} (default: @code{/var/www})
25897 The directory from which to serve the Let's Encrypt challenge/response
25900 @item @code{certificates} (default: @code{()})
25901 A list of @code{certificates-configuration}s for which to generate
25902 certificates and request signatures. Each certificate has a @code{name}
25903 and several @code{domains}.
25905 @item @code{email} (default: @code{#f})
25906 Optional email address used for registration and recovery contact.
25907 Setting this is encouraged as it allows you to receive important
25908 notifications about the account and issued certificates.
25910 @item @code{server} (default: @code{#f})
25911 Optional URL of ACME server. Setting this overrides certbot's default,
25912 which is the Let's Encrypt server.
25914 @item @code{rsa-key-size} (default: @code{2048})
25915 Size of the RSA key.
25917 @item @code{default-location} (default: @i{see below})
25918 The default @code{nginx-location-configuration}. Because @code{certbot}
25919 needs to be able to serve challenges and responses, it needs to be able
25920 to run a web server. It does so by extending the @code{nginx} web
25921 service with an @code{nginx-server-configuration} listening on the
25922 @var{domains} on port 80, and which has a
25923 @code{nginx-location-configuration} for the @code{/.well-known/} URI
25924 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
25925 these nginx configuration data types.
25927 Requests to other URL paths will be matched by the
25928 @code{default-location}, which if present is added to all
25929 @code{nginx-server-configuration}s.
25931 By default, the @code{default-location} will issue a redirect from
25932 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
25933 you to define what to serve on your site via @code{https}.
25935 Pass @code{#f} to not issue a default location.
25939 @deftp {Data Type} certificate-configuration
25940 Data type representing the configuration of a certificate.
25941 This type has the following parameters:
25944 @item @code{name} (default: @i{see below})
25945 This name is used by Certbot for housekeeping and in file paths; it
25946 doesn't affect the content of the certificate itself. To see
25947 certificate names, run @code{certbot certificates}.
25949 Its default is the first provided domain.
25951 @item @code{domains} (default: @code{()})
25952 The first domain provided will be the subject CN of the certificate, and
25953 all domains will be Subject Alternative Names on the certificate.
25955 @item @code{challenge} (default: @code{#f})
25956 The challenge type that has to be run by certbot. If @code{#f} is specified,
25957 default to the HTTP challenge. If a value is specified, defaults to the
25958 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
25959 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
25960 and gives Let's Encrypt permission to log the public IP address of the
25961 requesting machine.
25963 @item @code{csr} (default: @code{#f})
25964 File name of Certificate Signing Request (CSR) in DER or PEM format.
25965 If @code{#f} is specified, this argument will not be passed to certbot.
25966 If a value is specified, certbot will use it to obtain a certificate, instead of
25967 using a self-generated CSR.
25968 The domain-name(s) mentioned in @code{domains}, must be consistent with the
25969 domain-name(s) mentioned in CSR file.
25971 @item @code{authentication-hook} (default: @code{#f})
25972 Command to be run in a shell once for each certificate challenge to be
25973 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
25974 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
25975 contains the validation string and @code{$CERTBOT_TOKEN} contains the
25976 file name of the resource requested when performing an HTTP-01 challenge.
25978 @item @code{cleanup-hook} (default: @code{#f})
25979 Command to be run in a shell once for each certificate challenge that
25980 have been answered by the @code{auth-hook}. For this command, the shell
25981 variables available in the @code{auth-hook} script are still available, and
25982 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
25983 of the @code{auth-hook} script.
25985 @item @code{deploy-hook} (default: @code{#f})
25986 Command to be run in a shell once for each successfully issued
25987 certificate. For this command, the shell variable
25988 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
25989 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
25990 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
25991 contain a space-delimited list of renewed certificate domains (for
25992 example, @samp{"example.com www.example.com"}.
25997 For each @code{certificate-configuration}, the certificate is saved to
25998 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
25999 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
26001 @subsection DNS Services
26002 @cindex DNS (domain name system)
26003 @cindex domain name system (DNS)
26005 The @code{(gnu services dns)} module provides services related to the
26006 @dfn{domain name system} (DNS). It provides a server service for hosting
26007 an @emph{authoritative} DNS server for multiple zones, slave or master.
26008 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
26009 caching and forwarding DNS server for the LAN, which uses
26010 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
26012 @subsubheading Knot Service
26014 An example configuration of an authoritative server for two zones, one master
26018 (define-zone-entries example.org.zone
26019 ;; Name TTL Class Type Data
26020 ("@@" "" "IN" "A" "127.0.0.1")
26021 ("@@" "" "IN" "NS" "ns")
26022 ("ns" "" "IN" "A" "127.0.0.1"))
26024 (define master-zone
26025 (knot-zone-configuration
26026 (domain "example.org")
26028 (origin "example.org")
26029 (entries example.org.zone)))))
26032 (knot-zone-configuration
26033 (domain "plop.org")
26034 (dnssec-policy "default")
26035 (master (list "plop-master"))))
26037 (define plop-master
26038 (knot-remote-configuration
26040 (address (list "208.76.58.171"))))
26044 (services (cons* (service knot-service-type
26045 (knot-configuration
26046 (remotes (list plop-master))
26047 (zones (list master-zone slave-zone))))
26052 @deffn {Scheme Variable} knot-service-type
26053 This is the type for the Knot DNS server.
26055 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
26056 zones, that is to say domain names you would buy from a registrar. This server
26057 is not a resolver, meaning that it can only resolve names for which it is
26058 authoritative. This server can be configured to serve zones as a master server
26059 or a slave server as a per-zone basis. Slave zones will get their data from
26060 masters, and will serve it as an authoritative server. From the point of view
26061 of a resolver, there is no difference between master and slave.
26063 The following data types are used to configure the Knot DNS server:
26066 @deftp {Data Type} knot-key-configuration
26067 Data type representing a key.
26068 This type has the following parameters:
26071 @item @code{id} (default: @code{""})
26072 An identifier for other configuration fields to refer to this key. IDs must
26073 be unique and must not be empty.
26075 @item @code{algorithm} (default: @code{#f})
26076 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
26077 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
26078 and @code{'hmac-sha512}.
26080 @item @code{secret} (default: @code{""})
26081 The secret key itself.
26086 @deftp {Data Type} knot-acl-configuration
26087 Data type representing an Access Control List (ACL) configuration.
26088 This type has the following parameters:
26091 @item @code{id} (default: @code{""})
26092 An identifier for other configuration fields to refer to this key. IDs must be
26093 unique and must not be empty.
26095 @item @code{address} (default: @code{'()})
26096 An ordered list of IP addresses, network subnets, or network ranges represented
26097 with strings. The query must match one of them. Empty value means that
26098 address match is not required.
26100 @item @code{key} (default: @code{'()})
26101 An ordered list of references to keys represented with strings. The string
26102 must match a key ID defined in a @code{knot-key-configuration}. No key means
26103 that a key is not require to match that ACL.
26105 @item @code{action} (default: @code{'()})
26106 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
26107 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
26108 and @code{'update}.
26110 @item @code{deny?} (default: @code{#f})
26111 When true, the ACL defines restrictions. Listed actions are forbidden. When
26112 false, listed actions are allowed.
26117 @deftp {Data Type} zone-entry
26118 Data type representing a record entry in a zone file.
26119 This type has the following parameters:
26122 @item @code{name} (default: @code{"@@"})
26123 The name of the record. @code{"@@"} refers to the origin of the zone. Names
26124 are relative to the origin of the zone. For example, in the @code{example.org}
26125 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
26126 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
26127 refers to @code{ns.example.org}.
26129 @item @code{ttl} (default: @code{""})
26130 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
26132 @item @code{class} (default: @code{"IN"})
26133 The class of the record. Knot currently supports only @code{"IN"} and
26134 partially @code{"CH"}.
26136 @item @code{type} (default: @code{"A"})
26137 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
26138 address), NS (Name Server) and MX (Mail eXchange). Many other types are
26141 @item @code{data} (default: @code{""})
26142 The data contained in the record. For instance an IP address associated with
26143 an A record, or a domain name associated with an NS record. Remember that
26144 domain names are relative to the origin unless they end with a dot.
26149 @deftp {Data Type} zone-file
26150 Data type representing the content of a zone file.
26151 This type has the following parameters:
26154 @item @code{entries} (default: @code{'()})
26155 The list of entries. The SOA record is taken care of, so you don't need to
26156 put it in the list of entries. This list should probably contain an entry
26157 for your primary authoritative DNS server. Other than using a list of entries
26158 directly, you can use @code{define-zone-entries} to define a object containing
26159 the list of entries more easily, that you can later pass to the @code{entries}
26160 field of the @code{zone-file}.
26162 @item @code{origin} (default: @code{""})
26163 The name of your zone. This parameter cannot be empty.
26165 @item @code{ns} (default: @code{"ns"})
26166 The domain of your primary authoritative DNS server. The name is relative to
26167 the origin, unless it ends with a dot. It is mandatory that this primary
26168 DNS server corresponds to an NS record in the zone and that it is associated
26169 to an IP address in the list of entries.
26171 @item @code{mail} (default: @code{"hostmaster"})
26172 An email address people can contact you at, as the owner of the zone. This
26173 is translated as @code{<mail>@@<origin>}.
26175 @item @code{serial} (default: @code{1})
26176 The serial number of the zone. As this is used to keep track of changes by
26177 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
26178 Always increment it when you make a change in your zone.
26180 @item @code{refresh} (default: @code{(* 2 24 3600)})
26181 The frequency at which slaves will do a zone transfer. This value is a number
26182 of seconds. It can be computed by multiplications or with
26183 @code{(string->duration)}.
26185 @item @code{retry} (default: @code{(* 15 60)})
26186 The period after which a slave will retry to contact its master when it fails
26187 to do so a first time.
26189 @item @code{expiry} (default: @code{(* 14 24 3600)})
26190 Default TTL of records. Existing records are considered correct for at most
26191 this amount of time. After this period, resolvers will invalidate their cache
26192 and check again that it still exists.
26194 @item @code{nx} (default: @code{3600})
26195 Default TTL of inexistent records. This delay is usually short because you want
26196 your new domains to reach everyone quickly.
26201 @deftp {Data Type} knot-remote-configuration
26202 Data type representing a remote configuration.
26203 This type has the following parameters:
26206 @item @code{id} (default: @code{""})
26207 An identifier for other configuration fields to refer to this remote. IDs must
26208 be unique and must not be empty.
26210 @item @code{address} (default: @code{'()})
26211 An ordered list of destination IP addresses. Addresses are tried in sequence.
26212 An optional port can be given with the @@ separator. For instance:
26213 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
26215 @item @code{via} (default: @code{'()})
26216 An ordered list of source IP addresses. An empty list will have Knot choose
26217 an appropriate source IP@. An optional port can be given with the @@ separator.
26218 The default is to choose at random.
26220 @item @code{key} (default: @code{#f})
26221 A reference to a key, that is a string containing the identifier of a key
26222 defined in a @code{knot-key-configuration} field.
26227 @deftp {Data Type} knot-keystore-configuration
26228 Data type representing a keystore to hold dnssec keys.
26229 This type has the following parameters:
26232 @item @code{id} (default: @code{""})
26233 The id of the keystore. It must not be empty.
26235 @item @code{backend} (default: @code{'pem})
26236 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
26238 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
26239 The configuration string of the backend. An example for the PKCS#11 is:
26240 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
26241 For the pem backend, the string represents a path in the file system.
26246 @deftp {Data Type} knot-policy-configuration
26247 Data type representing a dnssec policy. Knot DNS is able to automatically
26248 sign your zones. It can either generate and manage your keys automatically or
26249 use keys that you generate.
26251 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
26252 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
26253 zone. In order to be trusted, the KSK needs to be present in the parent zone
26254 (usually a top-level domain). If your registrar supports dnssec, you will
26255 have to send them your KSK's hash so they can add a DS record in their zone.
26256 This is not automated and need to be done each time you change your KSK.
26258 The policy also defines the lifetime of keys. Usually, ZSK can be changed
26259 easily and use weaker cryptographic functions (they use lower parameters) in
26260 order to sign records quickly, so they are changed often. The KSK however
26261 requires manual interaction with the registrar, so they are changed less often
26262 and use stronger parameters because they sign only one record.
26264 This type has the following parameters:
26267 @item @code{id} (default: @code{""})
26268 The id of the policy. It must not be empty.
26270 @item @code{keystore} (default: @code{"default"})
26271 A reference to a keystore, that is a string containing the identifier of a
26272 keystore defined in a @code{knot-keystore-configuration} field. The
26273 @code{"default"} identifier means the default keystore (a kasp database that
26274 was setup by this service).
26276 @item @code{manual?} (default: @code{#f})
26277 Whether the key management is manual or automatic.
26279 @item @code{single-type-signing?} (default: @code{#f})
26280 When @code{#t}, use the Single-Type Signing Scheme.
26282 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
26283 An algorithm of signing keys and issued signatures.
26285 @item @code{ksk-size} (default: @code{256})
26286 The length of the KSK@. Note that this value is correct for the default
26287 algorithm, but would be unsecure for other algorithms.
26289 @item @code{zsk-size} (default: @code{256})
26290 The length of the ZSK@. Note that this value is correct for the default
26291 algorithm, but would be unsecure for other algorithms.
26293 @item @code{dnskey-ttl} (default: @code{'default})
26294 The TTL value for DNSKEY records added into zone apex. The special
26295 @code{'default} value means same as the zone SOA TTL.
26297 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
26298 The period between ZSK publication and the next rollover initiation.
26300 @item @code{propagation-delay} (default: @code{(* 24 3600)})
26301 An extra delay added for each key rollover step. This value should be high
26302 enough to cover propagation of data from the master server to all slaves.
26304 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
26305 A validity period of newly issued signatures.
26307 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
26308 A period how long before a signature expiration the signature will be refreshed.
26310 @item @code{nsec3?} (default: @code{#f})
26311 When @code{#t}, NSEC3 will be used instead of NSEC.
26313 @item @code{nsec3-iterations} (default: @code{5})
26314 The number of additional times the hashing is performed.
26316 @item @code{nsec3-salt-length} (default: @code{8})
26317 The length of a salt field in octets, which is appended to the original owner
26318 name before hashing.
26320 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
26321 The validity period of newly issued salt field.
26326 @deftp {Data Type} knot-zone-configuration
26327 Data type representing a zone served by Knot.
26328 This type has the following parameters:
26331 @item @code{domain} (default: @code{""})
26332 The domain served by this configuration. It must not be empty.
26334 @item @code{file} (default: @code{""})
26335 The file where this zone is saved. This parameter is ignored by master zones.
26336 Empty means default location that depends on the domain name.
26338 @item @code{zone} (default: @code{(zone-file)})
26339 The content of the zone file. This parameter is ignored by slave zones. It
26340 must contain a zone-file record.
26342 @item @code{master} (default: @code{'()})
26343 A list of master remotes. When empty, this zone is a master. When set, this
26344 zone is a slave. This is a list of remotes identifiers.
26346 @item @code{ddns-master} (default: @code{#f})
26347 The main master. When empty, it defaults to the first master in the list of
26350 @item @code{notify} (default: @code{'()})
26351 A list of slave remote identifiers.
26353 @item @code{acl} (default: @code{'()})
26354 A list of acl identifiers.
26356 @item @code{semantic-checks?} (default: @code{#f})
26357 When set, this adds more semantic checks to the zone.
26359 @item @code{disable-any?} (default: @code{#f})
26360 When set, this forbids queries of the ANY type.
26362 @item @code{zonefile-sync} (default: @code{0})
26363 The delay between a modification in memory and on disk. 0 means immediate
26366 @item @code{zonefile-load} (default: @code{#f})
26367 The way the zone file contents are applied during zone load. Possible values
26371 @item @code{#f} for using the default value from Knot,
26372 @item @code{'none} for not using the zone file at all,
26373 @item @code{'difference} for computing the difference between already available
26374 contents and zone contents and applying it to the current zone contents,
26375 @item @code{'difference-no-serial} for the same as @code{'difference}, but
26376 ignoring the SOA serial in the zone file, while the server takes care of it
26378 @item @code{'whole} for loading zone contents from the zone file.
26381 @item @code{journal-content} (default: @code{#f})
26382 The way the journal is used to store zone and its changes. Possible values
26383 are @code{'none} to not use it at all, @code{'changes} to store changes and
26384 @code{'all} to store contents. @code{#f} does not set this option, so the
26385 default value from Knot is used.
26387 @item @code{max-journal-usage} (default: @code{#f})
26388 The maximum size for the journal on disk. @code{#f} does not set this option,
26389 so the default value from Knot is used.
26391 @item @code{max-journal-depth} (default: @code{#f})
26392 The maximum size of the history. @code{#f} does not set this option, so the
26393 default value from Knot is used.
26395 @item @code{max-zone-size} (default: @code{#f})
26396 The maximum size of the zone file. This limit is enforced for incoming
26397 transfer and updates. @code{#f} does not set this option, so the default
26398 value from Knot is used.
26400 @item @code{dnssec-policy} (default: @code{#f})
26401 A reference to a @code{knot-policy-configuration} record, or the special
26402 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
26405 @item @code{serial-policy} (default: @code{'increment})
26406 A policy between @code{'increment} and @code{'unixtime}.
26411 @deftp {Data Type} knot-configuration
26412 Data type representing the Knot configuration.
26413 This type has the following parameters:
26416 @item @code{knot} (default: @code{knot})
26419 @item @code{run-directory} (default: @code{"/var/run/knot"})
26420 The run directory. This directory will be used for pid file and sockets.
26422 @item @code{includes} (default: @code{'()})
26423 A list of strings or file-like objects denoting other files that must be
26424 included at the top of the configuration file.
26426 @cindex secrets, Knot service
26427 This can be used to manage secrets out-of-band. For example, secret
26428 keys may be stored in an out-of-band file not managed by Guix, and
26429 thus not visible in @file{/gnu/store}---e.g., you could store secret
26430 key configuration in @file{/etc/knot/secrets.conf} and add this file
26431 to the @code{includes} list.
26433 One can generate a secret tsig key (for nsupdate and zone transfers with the
26434 keymgr command from the knot package. Note that the package is not automatically
26435 installed by the service. The following example shows how to generate a new
26439 keymgr -t mysecret > /etc/knot/secrets.conf
26440 chmod 600 /etc/knot/secrets.conf
26443 Also note that the generated key will be named @var{mysecret}, so it is the
26444 name that needs to be used in the @var{key} field of the
26445 @code{knot-acl-configuration} record and in other places that need to refer
26448 It can also be used to add configuration not supported by this interface.
26450 @item @code{listen-v4} (default: @code{"0.0.0.0"})
26451 An ip address on which to listen.
26453 @item @code{listen-v6} (default: @code{"::"})
26454 An ip address on which to listen.
26456 @item @code{listen-port} (default: @code{53})
26457 A port on which to listen.
26459 @item @code{keys} (default: @code{'()})
26460 The list of knot-key-configuration used by this configuration.
26462 @item @code{acls} (default: @code{'()})
26463 The list of knot-acl-configuration used by this configuration.
26465 @item @code{remotes} (default: @code{'()})
26466 The list of knot-remote-configuration used by this configuration.
26468 @item @code{zones} (default: @code{'()})
26469 The list of knot-zone-configuration used by this configuration.
26474 @subsubheading Knot Resolver Service
26476 @deffn {Scheme Variable} knot-resolver-service-type
26477 This is the type of the knot resolver service, whose value should be
26478 an @code{knot-resolver-configuration} object as in this example:
26481 (service knot-resolver-service-type
26482 (knot-resolver-configuration
26483 (kresd-config-file (plain-file "kresd.conf" "
26484 net.listen('192.168.0.1', 5353)
26485 user('knot-resolver', 'knot-resolver')
26486 modules = @{ 'hints > iterate', 'stats', 'predict' @}
26487 cache.size = 100 * MB
26491 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
26494 @deftp {Data Type} knot-resolver-configuration
26495 Data type representing the configuration of knot-resolver.
26498 @item @code{package} (default: @var{knot-resolver})
26499 Package object of the knot DNS resolver.
26501 @item @code{kresd-config-file} (default: %kresd.conf)
26502 File-like object of the kresd configuration file to use, by default it
26503 will listen on @code{127.0.0.1} and @code{::1}.
26505 @item @code{garbage-collection-interval} (default: 1000)
26506 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
26512 @subsubheading Dnsmasq Service
26514 @deffn {Scheme Variable} dnsmasq-service-type
26515 This is the type of the dnsmasq service, whose value should be an
26516 @code{dnsmasq-configuration} object as in this example:
26519 (service dnsmasq-service-type
26520 (dnsmasq-configuration
26522 (servers '("192.168.1.1"))))
26526 @deftp {Data Type} dnsmasq-configuration
26527 Data type representing the configuration of dnsmasq.
26530 @item @code{package} (default: @var{dnsmasq})
26531 Package object of the dnsmasq server.
26533 @item @code{no-hosts?} (default: @code{#f})
26534 When true, don't read the hostnames in /etc/hosts.
26536 @item @code{port} (default: @code{53})
26537 The port to listen on. Setting this to zero completely disables DNS
26538 responses, leaving only DHCP and/or TFTP functions.
26540 @item @code{local-service?} (default: @code{#t})
26541 Accept DNS queries only from hosts whose address is on a local subnet,
26542 ie a subnet for which an interface exists on the server.
26544 @item @code{listen-addresses} (default: @code{'()})
26545 Listen on the given IP addresses.
26547 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
26548 The file to read the IP address of the upstream nameservers from.
26550 @item @code{no-resolv?} (default: @code{#f})
26551 When true, don't read @var{resolv-file}.
26553 @item @code{servers} (default: @code{'()})
26554 Specify IP address of upstream servers directly.
26556 @item @code{addresses} (default: @code{'()})
26557 For each entry, specify an IP address to return for any host in the
26558 given domains. Queries in the domains are never forwarded and always
26559 replied to with the specified IP address.
26561 This is useful for redirecting hosts locally, for example:
26564 (service dnsmasq-service-type
26565 (dnsmasq-configuration
26567 '(; Redirect to a local web-server.
26568 "/example.org/127.0.0.1"
26569 ; Redirect subdomain to a specific IP.
26570 "/subdomain.example.org/192.168.1.42"))))
26573 Note that rules in @file{/etc/hosts} take precedence over this.
26575 @item @code{cache-size} (default: @code{150})
26576 Set the size of dnsmasq's cache. Setting the cache size to zero
26579 @item @code{negative-cache?} (default: @code{#t})
26580 When false, disable negative caching.
26582 @item @code{tftp-enable?} (default: @code{#f})
26583 Whether to enable the built-in TFTP server.
26585 @item @code{tftp-no-fail?} (default: @code{#f})
26586 If true, does not fail dnsmasq if the TFTP server could not start up.
26588 @item @code{tftp-single-port?} (default: @code{#f})
26589 Whether to use only one single port for TFTP.
26591 @item @code{tftp-secure?} (default: @code{#f})
26592 If true, only files owned by the user running the dnsmasq process are accessible.
26594 If dnsmasq is being run as root, different rules apply:
26595 @code{tftp-secure?} has no effect, but only files which have the
26596 world-readable bit set are accessible.
26598 @item @code{tftp-max} (default: @code{#f})
26599 If set, sets the maximal number of concurrent connections allowed.
26601 @item @code{tftp-mtu} (default: @code{#f})
26602 If set, sets the MTU for TFTP packets to that value.
26604 @item @code{tftp-no-blocksize?} (default: @code{#f})
26605 If true, stops the TFTP server from negotiating the blocksize with a client.
26607 @item @code{tftp-lowercase?} (default: @code{#f})
26608 Whether to convert all filenames in TFTP requests to lowercase.
26610 @item @code{tftp-port-range} (default: @code{#f})
26611 If set, fixes the dynamical ports (one per client) to the given range
26612 (@code{"<start>,<end>"}).
26614 @item @code{tftp-root} (default: @code{/var/empty,lo})
26615 Look for files to transfer using TFTP relative to the given directory.
26616 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
26617 getting outside the specified root. Absolute paths (starting with @samp{/}) are
26618 allowed, but they must be within the TFTP-root. If the optional interface
26619 argument is given, the directory is only used for TFTP requests via that
26622 @item @code{tftp-unique-root} (default: @code{#f})
26623 If set, add the IP or hardware address of the TFTP client as a path component
26624 on the end of the TFTP-root. Only valid if a TFTP root is set and the
26625 directory exists. Defaults to adding IP address (in standard dotted-quad
26628 For instance, if @option{--tftp-root} is @samp{/tftp} and client
26629 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
26630 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
26631 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
26632 append the MAC address instead, using lowercase zero padded digits
26633 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
26634 resolving MAC addresses is only possible if the client is in the local
26635 network or obtained a DHCP lease from dnsmasq.
26640 @subsubheading ddclient Service
26643 The ddclient service described below runs the ddclient daemon, which takes
26644 care of automatically updating DNS entries for service providers such as
26645 @uref{https://dyn.com/dns/, Dyn}.
26647 The following example show instantiates the service with its default
26651 (service ddclient-service-type)
26654 Note that ddclient needs to access credentials that are stored in a
26655 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
26656 @code{secret-file} below). You are expected to create this file manually, in
26657 an ``out-of-band'' fashion (you @emph{could} make this file part of the
26658 service configuration, for instance by using @code{plain-file}, but it will be
26659 world-readable @i{via} @file{/gnu/store}). See the examples in the
26660 @file{share/ddclient} directory of the @code{ddclient} package.
26662 @c %start of fragment
26664 Available @code{ddclient-configuration} fields are:
26666 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
26667 The ddclient package.
26671 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
26672 The period after which ddclient will retry to check IP and domain name.
26674 Defaults to @samp{300}.
26678 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
26679 Use syslog for the output.
26681 Defaults to @samp{#t}.
26685 @deftypevr {@code{ddclient-configuration} parameter} string mail
26688 Defaults to @samp{"root"}.
26692 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
26693 Mail failed update to user.
26695 Defaults to @samp{"root"}.
26699 @deftypevr {@code{ddclient-configuration} parameter} string pid
26700 The ddclient PID file.
26702 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
26706 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
26707 Enable SSL support.
26709 Defaults to @samp{#t}.
26713 @deftypevr {@code{ddclient-configuration} parameter} string user
26714 Specifies the user name or ID that is used when running ddclient
26717 Defaults to @samp{"ddclient"}.
26721 @deftypevr {@code{ddclient-configuration} parameter} string group
26722 Group of the user who will run the ddclient program.
26724 Defaults to @samp{"ddclient"}.
26728 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
26729 Secret file which will be appended to @file{ddclient.conf} file. This
26730 file contains credentials for use by ddclient. You are expected to
26731 create it manually.
26733 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
26737 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
26738 Extra options will be appended to @file{ddclient.conf} file.
26740 Defaults to @samp{()}.
26745 @c %end of fragment
26749 @subsection VPN Services
26750 @cindex VPN (virtual private network)
26751 @cindex virtual private network (VPN)
26753 The @code{(gnu services vpn)} module provides services related to
26754 @dfn{virtual private networks} (VPNs).
26756 @subsubheading OpenVPN
26758 It provides a @emph{client} service for your machine to connect to a
26759 VPN, and a @emph{server} service for your machine to host a VPN@.
26761 @deffn {Scheme Procedure} openvpn-client-service @
26762 [#:config (openvpn-client-configuration)]
26764 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
26767 @deffn {Scheme Procedure} openvpn-server-service @
26768 [#:config (openvpn-server-configuration)]
26770 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
26772 Both can be run simultaneously.
26775 @c %automatically generated documentation
26777 Available @code{openvpn-client-configuration} fields are:
26779 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
26780 The OpenVPN package.
26784 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
26785 The OpenVPN pid file.
26787 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26791 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
26792 The protocol (UDP or TCP) used to open a channel between clients and
26795 Defaults to @samp{udp}.
26799 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
26800 The device type used to represent the VPN connection.
26802 Defaults to @samp{tun}.
26806 If you do not have some of these files (eg.@: you use a username and
26807 password), you can disable any of the following three fields by setting
26808 it to @code{'disabled}.
26810 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
26811 The certificate authority to check connections against.
26813 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26817 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
26818 The certificate of the machine the daemon is running on. It should be
26819 signed by the authority given in @code{ca}.
26821 Defaults to @samp{"/etc/openvpn/client.crt"}.
26825 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
26826 The key of the machine the daemon is running on. It must be the key whose
26827 certificate is @code{cert}.
26829 Defaults to @samp{"/etc/openvpn/client.key"}.
26833 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
26834 Whether to use the lzo compression algorithm.
26836 Defaults to @samp{#t}.
26840 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
26841 Don't re-read key files across SIGUSR1 or --ping-restart.
26843 Defaults to @samp{#t}.
26847 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
26848 Don't close and reopen TUN/TAP device or run up/down scripts across
26849 SIGUSR1 or --ping-restart restarts.
26851 Defaults to @samp{#t}.
26855 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
26856 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26857 poll/epoll/select prior to the write operation.
26859 Defaults to @samp{#f}.
26862 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
26865 Defaults to @samp{3}.
26869 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
26870 Add an additional layer of HMAC authentication on top of the TLS control
26871 channel to protect against DoS attacks.
26873 Defaults to @samp{#f}.
26877 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
26878 Authenticate with server using username/password. The option is a file
26879 containing username/password on 2 lines. Do not use a file-like object as it
26880 would be added to the store and readable by any user.
26882 Defaults to @samp{'disabled}.
26885 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
26886 Whether to check the server certificate has server usage extension.
26888 Defaults to @samp{#t}.
26892 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
26893 Bind to a specific local port number.
26895 Defaults to @samp{#f}.
26899 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
26900 Retry resolving server address.
26902 Defaults to @samp{#t}.
26906 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
26907 A list of remote servers to connect to.
26909 Defaults to @samp{()}.
26911 Available @code{openvpn-remote-configuration} fields are:
26913 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
26916 Defaults to @samp{"my-server"}.
26920 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
26921 Port number the server listens to.
26923 Defaults to @samp{1194}.
26928 @c %end of automatic openvpn-client documentation
26930 @c %automatically generated documentation
26932 Available @code{openvpn-server-configuration} fields are:
26934 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
26935 The OpenVPN package.
26939 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
26940 The OpenVPN pid file.
26942 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26946 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
26947 The protocol (UDP or TCP) used to open a channel between clients and
26950 Defaults to @samp{udp}.
26954 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
26955 The device type used to represent the VPN connection.
26957 Defaults to @samp{tun}.
26961 If you do not have some of these files (eg.@: you use a username and
26962 password), you can disable any of the following three fields by setting
26963 it to @code{'disabled}.
26965 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
26966 The certificate authority to check connections against.
26968 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26972 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
26973 The certificate of the machine the daemon is running on. It should be
26974 signed by the authority given in @code{ca}.
26976 Defaults to @samp{"/etc/openvpn/client.crt"}.
26980 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
26981 The key of the machine the daemon is running on. It must be the key whose
26982 certificate is @code{cert}.
26984 Defaults to @samp{"/etc/openvpn/client.key"}.
26988 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
26989 Whether to use the lzo compression algorithm.
26991 Defaults to @samp{#t}.
26995 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
26996 Don't re-read key files across SIGUSR1 or --ping-restart.
26998 Defaults to @samp{#t}.
27002 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
27003 Don't close and reopen TUN/TAP device or run up/down scripts across
27004 SIGUSR1 or --ping-restart restarts.
27006 Defaults to @samp{#t}.
27010 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
27011 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
27012 poll/epoll/select prior to the write operation.
27014 Defaults to @samp{#f}.
27017 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
27020 Defaults to @samp{3}.
27024 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
27025 Add an additional layer of HMAC authentication on top of the TLS control
27026 channel to protect against DoS attacks.
27028 Defaults to @samp{#f}.
27032 @deftypevr {@code{openvpn-server-configuration} parameter} number port
27033 Specifies the port number on which the server listens.
27035 Defaults to @samp{1194}.
27039 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
27040 An ip and mask specifying the subnet inside the virtual network.
27042 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
27046 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
27047 A CIDR notation specifying the IPv6 subnet inside the virtual network.
27049 Defaults to @samp{#f}.
27053 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
27054 The Diffie-Hellman parameters file.
27056 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
27060 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
27061 The file that records client IPs.
27063 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
27067 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
27068 When true, the server will act as a gateway for its clients.
27070 Defaults to @samp{#f}.
27074 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
27075 When true, clients are allowed to talk to each other inside the VPN.
27077 Defaults to @samp{#f}.
27081 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
27082 Causes ping-like messages to be sent back and forth over the link so
27083 that each side knows when the other side has gone down. @code{keepalive}
27084 requires a pair. The first element is the period of the ping sending,
27085 and the second element is the timeout before considering the other side
27090 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
27091 The maximum number of clients.
27093 Defaults to @samp{100}.
27097 @deftypevr {@code{openvpn-server-configuration} parameter} string status
27098 The status file. This file shows a small report on current connection.
27099 It is truncated and rewritten every minute.
27101 Defaults to @samp{"/var/run/openvpn/status"}.
27105 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
27106 The list of configuration for some clients.
27108 Defaults to @samp{()}.
27110 Available @code{openvpn-ccd-configuration} fields are:
27112 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
27115 Defaults to @samp{"client"}.
27119 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
27122 Defaults to @samp{#f}.
27126 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
27129 Defaults to @samp{#f}.
27135 @c %end of automatic openvpn-server documentation
27137 @subheading strongSwan
27139 Currently, the strongSwan service only provides legacy-style configuration with
27140 @file{ipsec.conf} and @file{ipsec.secrets} files.
27142 @defvr {Scheme Variable} strongswan-service-type
27143 A service type for configuring strongSwan for IPsec @acronym{VPN,
27144 Virtual Private Networking}. Its value must be a
27145 @code{strongswan-configuration} record as in this example:
27148 (service strongswan-service-type
27149 (strongswan-configuration
27150 (ipsec-conf "/etc/ipsec.conf")
27151 (ipsec-secrets "/etc/ipsec.secrets")))
27156 @deftp {Data Type} strongswan-configuration
27157 Data type representing the configuration of the StrongSwan service.
27160 @item @code{strongswan}
27161 The strongSwan package to use for this service.
27163 @item @code{ipsec-conf} (default: @code{#f})
27164 The file name of your @file{ipsec.conf}. If not @code{#f}, then this and
27165 @code{ipsec-secrets} must both be strings.
27167 @item @code{ipsec-secrets} (default @code{#f})
27168 The file name of your @file{ipsec.secrets}. If not @code{#f}, then this and
27169 @code{ipsec-conf} must both be strings.
27174 @subsubheading Wireguard
27176 @defvr {Scheme Variable} wireguard-service-type
27177 A service type for a Wireguard tunnel interface. Its value must be a
27178 @code{wireguard-configuration} record as in this example:
27181 (service wireguard-service-type
27182 (wireguard-configuration
27187 (endpoint "my.wireguard.com:51820")
27188 (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
27189 (allowed-ips '("10.0.0.2/32")))))))
27194 @deftp {Data Type} wireguard-configuration
27195 Data type representing the configuration of the Wireguard service.
27198 @item @code{wireguard}
27199 The wireguard package to use for this service.
27201 @item @code{interface} (default: @code{"wg0"})
27202 The interface name for the VPN.
27204 @item @code{addresses} (default: @code{'("10.0.0.1/32")})
27205 The IP addresses to be assigned to the above interface.
27207 @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
27208 The private key file for the interface. It is automatically generated if
27209 the file does not exist.
27211 @item @code{peers} (default: @code{'()})
27212 The authorized peers on this interface. This is a list of
27213 @var{wireguard-peer} records.
27218 @deftp {Data Type} wireguard-peer
27219 Data type representing a Wireguard peer attached to a given interface.
27225 @item @code{endpoint} (default: @code{#f})
27226 The optional endpoint for the peer, such as
27227 @code{"demo.wireguard.com:51820"}.
27229 @item @code{public-key}
27230 The peer public-key represented as a base64 string.
27232 @item @code{allowed-ips}
27233 A list of IP addresses from which incoming traffic for this peer is
27234 allowed and to which incoming traffic for this peer is directed.
27236 @item @code{keep-alive} (default: @code{#f})
27237 An optional time interval in seconds. A packet will be sent to the
27238 server endpoint once per time interval. This helps receiving
27239 incoming connections from this peer when you are behind a NAT or
27245 @node Network File System
27246 @subsection Network File System
27249 The @code{(gnu services nfs)} module provides the following services,
27250 which are most commonly used in relation to mounting or exporting
27251 directory trees as @dfn{network file systems} (NFS).
27253 While it is possible to use the individual components that together make
27254 up a Network File System service, we recommended to configure an NFS
27255 server with the @code{nfs-service-type}.
27257 @subsubheading NFS Service
27258 @cindex NFS, server
27260 The NFS service takes care of setting up all NFS component services,
27261 kernel configuration file systems, and installs configuration files in
27262 the locations that NFS expects.
27264 @defvr {Scheme Variable} nfs-service-type
27265 A service type for a complete NFS server.
27268 @deftp {Data Type} nfs-configuration
27269 This data type represents the configuration of the NFS service and all
27272 It has the following parameters:
27274 @item @code{nfs-utils} (default: @code{nfs-utils})
27275 The nfs-utils package to use.
27277 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
27278 If a list of string values is provided, the @command{rpc.nfsd} daemon
27279 will be limited to supporting the given versions of the NFS protocol.
27281 @item @code{exports} (default: @code{'()})
27282 This is a list of directories the NFS server should export. Each entry
27283 is a list consisting of two elements: a directory name and a string
27284 containing all options. This is an example in which the directory
27285 @file{/export} is served to all NFS clients as a read-only share:
27291 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
27294 @item @code{rpcmountd-port} (default: @code{#f})
27295 The network port that the @command{rpc.mountd} daemon should use.
27297 @item @code{rpcstatd-port} (default: @code{#f})
27298 The network port that the @command{rpc.statd} daemon should use.
27300 @item @code{rpcbind} (default: @code{rpcbind})
27301 The rpcbind package to use.
27303 @item @code{idmap-domain} (default: @code{"localdomain"})
27304 The local NFSv4 domain name.
27306 @item @code{nfsd-port} (default: @code{2049})
27307 The network port that the @command{nfsd} daemon should use.
27309 @item @code{nfsd-threads} (default: @code{8})
27310 The number of threads used by the @command{nfsd} daemon.
27312 @item @code{nfsd-tcp?} (default: @code{#t})
27313 Whether the @command{nfsd} daemon should listen on a TCP socket.
27315 @item @code{nfsd-udp?} (default: @code{#f})
27316 Whether the @command{nfsd} daemon should listen on a UDP socket.
27318 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27319 The directory where the pipefs file system is mounted.
27321 @item @code{debug} (default: @code{'()"})
27322 A list of subsystems for which debugging output should be enabled. This
27323 is a list of symbols. Any of these symbols are valid: @code{nfsd},
27324 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
27328 If you don't need a complete NFS service or prefer to build it yourself
27329 you can use the individual component services that are documented below.
27331 @subsubheading RPC Bind Service
27334 The RPC Bind service provides a facility to map program numbers into
27335 universal addresses.
27336 Many NFS related services use this facility. Hence it is automatically
27337 started when a dependent service starts.
27339 @defvr {Scheme Variable} rpcbind-service-type
27340 A service type for the RPC portmapper daemon.
27344 @deftp {Data Type} rpcbind-configuration
27345 Data type representing the configuration of the RPC Bind Service.
27346 This type has the following parameters:
27348 @item @code{rpcbind} (default: @code{rpcbind})
27349 The rpcbind package to use.
27351 @item @code{warm-start?} (default: @code{#t})
27352 If this parameter is @code{#t}, then the daemon will read a
27353 state file on startup thus reloading state information saved by a previous
27359 @subsubheading Pipefs Pseudo File System
27363 The pipefs file system is used to transfer NFS related data
27364 between the kernel and user space programs.
27366 @defvr {Scheme Variable} pipefs-service-type
27367 A service type for the pipefs pseudo file system.
27370 @deftp {Data Type} pipefs-configuration
27371 Data type representing the configuration of the pipefs pseudo file system service.
27372 This type has the following parameters:
27374 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27375 The directory to which the file system is to be attached.
27380 @subsubheading GSS Daemon Service
27383 @cindex global security system
27385 The @dfn{global security system} (GSS) daemon provides strong security for RPC
27387 Before exchanging RPC requests an RPC client must establish a security
27388 context. Typically this is done using the Kerberos command @command{kinit}
27389 or automatically at login time using PAM services (@pxref{Kerberos Services}).
27391 @defvr {Scheme Variable} gss-service-type
27392 A service type for the Global Security System (GSS) daemon.
27395 @deftp {Data Type} gss-configuration
27396 Data type representing the configuration of the GSS daemon service.
27397 This type has the following parameters:
27399 @item @code{nfs-utils} (default: @code{nfs-utils})
27400 The package in which the @command{rpc.gssd} command is to be found.
27402 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27403 The directory where the pipefs file system is mounted.
27409 @subsubheading IDMAP Daemon Service
27411 @cindex name mapper
27413 The idmap daemon service provides mapping between user IDs and user names.
27414 Typically it is required in order to access file systems mounted via NFSv4.
27416 @defvr {Scheme Variable} idmap-service-type
27417 A service type for the Identity Mapper (IDMAP) daemon.
27420 @deftp {Data Type} idmap-configuration
27421 Data type representing the configuration of the IDMAP daemon service.
27422 This type has the following parameters:
27424 @item @code{nfs-utils} (default: @code{nfs-utils})
27425 The package in which the @command{rpc.idmapd} command is to be found.
27427 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27428 The directory where the pipefs file system is mounted.
27430 @item @code{domain} (default: @code{#f})
27431 The local NFSv4 domain name.
27432 This must be a string or @code{#f}.
27433 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
27435 @item @code{verbosity} (default: @code{0})
27436 The verbosity level of the daemon.
27441 @node Continuous Integration
27442 @subsection Continuous Integration
27444 @cindex continuous integration
27445 @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
27446 integration tool for Guix. It can be used both for development and for
27447 providing substitutes to others (@pxref{Substitutes}).
27449 The @code{(gnu services cuirass)} module provides the following service.
27451 @defvr {Scheme Procedure} cuirass-service-type
27452 The type of the Cuirass service. Its value must be a
27453 @code{cuirass-configuration} object, as described below.
27456 To add build jobs, you have to set the @code{specifications} field of
27457 the configuration. For instance, the following example will build all
27458 the packages provided by the @code{my-channel} channel.
27461 (define %cuirass-specs
27462 #~(list (specification
27463 (name "my-channel")
27464 (build '(channels my-channel))
27468 (url "https://my-channel.git"))
27469 %default-channels)))))
27471 (service cuirass-service-type
27472 (cuirass-configuration
27473 (specifications %cuirass-specs)))
27476 To build the @code{linux-libre} package defined by the default Guix
27477 channel, one can use the following configuration.
27480 (define %cuirass-specs
27481 #~(list (specification
27483 (build '(packages "linux-libre")))))
27485 (service cuirass-service-type
27486 (cuirass-configuration
27487 (specifications %cuirass-specs)))
27490 The other configuration possibilities, as well as the specification
27491 record itself are described in the Cuirass manual
27492 (@pxref{Specifications,,, cuirass, Cuirass}).
27494 While information related to build jobs is located directly in the
27495 specifications, global settings for the @command{cuirass} process are
27496 accessible in other @code{cuirass-configuration} fields.
27498 @deftp {Data Type} cuirass-configuration
27499 Data type representing the configuration of Cuirass.
27502 @item @code{cuirass} (default: @code{cuirass})
27503 The Cuirass package to use.
27505 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
27506 Location of the log file.
27508 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
27509 Location of the log file used by the web interface.
27511 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
27512 Location of the repository cache.
27514 @item @code{user} (default: @code{"cuirass"})
27515 Owner of the @code{cuirass} process.
27517 @item @code{group} (default: @code{"cuirass"})
27518 Owner's group of the @code{cuirass} process.
27520 @item @code{interval} (default: @code{60})
27521 Number of seconds between the poll of the repositories followed by the
27524 @item @code{parameters} (default: @code{#f})
27525 Read parameters from the given @var{parameters} file. The supported
27526 parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
27528 @item @code{remote-server} (default: @code{#f})
27529 A @code{cuirass-remote-server-configuration} record to use the build
27530 remote mechanism or @code{#f} to use the default build mechanism.
27532 @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
27533 Use @var{database} as the database containing the jobs and the past
27534 build results. Since Cuirass uses PostgreSQL as a database engine,
27535 @var{database} must be a string such as @code{"dbname=cuirass
27538 @item @code{port} (default: @code{8081})
27539 Port number used by the HTTP server.
27541 @item @code{host} (default: @code{"localhost"})
27542 Listen on the network interface for @var{host}. The default is to
27543 accept connections from localhost.
27545 @item @code{specifications} (default: @code{#~'()})
27546 A gexp (@pxref{G-Expressions}) that evaluates to a list of
27547 specifications records. The specification record is described in the
27548 Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
27550 @item @code{use-substitutes?} (default: @code{#f})
27551 This allows using substitutes to avoid building every dependencies of a job
27554 @item @code{one-shot?} (default: @code{#f})
27555 Only evaluate specifications and build derivations once.
27557 @item @code{fallback?} (default: @code{#f})
27558 When substituting a pre-built binary fails, fall back to building
27561 @item @code{extra-options} (default: @code{'()})
27562 Extra options to pass when running the Cuirass processes.
27567 @cindex remote build
27568 @subsubheading Cuirass remote building
27570 Cuirass supports two mechanisms to build derivations.
27573 @item Using the local Guix daemon.
27574 This is the default build mechanism. Once the build jobs are
27575 evaluated, they are sent to the local Guix daemon. Cuirass then
27576 listens to the Guix daemon output to detect the various build events.
27578 @item Using the remote build mechanism.
27579 The build jobs are not submitted to the local Guix daemon. Instead, a
27580 remote server dispatches build requests to the connect remote workers,
27581 according to the build priorities.
27585 To enable this build mode a @code{cuirass-remote-server-configuration}
27586 record must be passed as @code{remote-server} argument of the
27587 @code{cuirass-configuration} record. The
27588 @code{cuirass-remote-server-configuration} record is described below.
27590 This build mode scales way better than the default build mode. This is
27591 the build mode that is used on the GNU Guix build farm at
27592 @url{https://ci.guix.gnu.org}. It should be preferred when using
27593 Cuirass to build large amount of packages.
27595 @deftp {Data Type} cuirass-remote-server-configuration
27596 Data type representing the configuration of the Cuirass remote-server.
27599 @item @code{backend-port} (default: @code{5555})
27600 The TCP port for communicating with @code{remote-worker} processes
27601 using ZMQ. It defaults to @code{5555}.
27603 @item @code{log-port} (default: @code{5556})
27604 The TCP port of the log server. It defaults to @code{5556}.
27606 @item @code{publish-port} (default: @code{5557})
27607 The TCP port of the publish server. It defaults to @code{5557}.
27609 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
27610 Location of the log file.
27612 @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
27613 Use @var{cache} directory to cache build log files.
27615 @item @code{trigger-url} (default: @code{#f})
27616 Once a substitute is successfully fetched, trigger substitute baking at
27619 @item @code{public-key}
27620 @item @code{private-key}
27621 Use the specific @var{file}s as the public/private key pair used to sign
27622 the store items being published.
27627 At least one remote worker must also be started on any machine of the
27628 local network to actually perform the builds and report their status.
27630 @deftp {Data Type} cuirass-remote-worker-configuration
27631 Data type representing the configuration of the Cuirass remote-worker.
27634 @item @code{cuirass} (default: @code{cuirass})
27635 The Cuirass package to use.
27637 @item @code{workers} (default: @code{1})
27638 Start @var{workers} parallel workers.
27640 @item @code{server} (default: @code{#f})
27641 Do not use Avahi discovery and connect to the given @code{server} IP
27644 @item @code{systems} (default: @code{(list (%current-system))})
27645 Only request builds for the given @var{systems}.
27647 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
27648 Location of the log file.
27650 @item @code{publish-port} (default: @code{5558})
27651 The TCP port of the publish server. It defaults to @code{5558}.
27653 @item @code{public-key}
27654 @item @code{private-key}
27655 Use the specific @var{file}s as the public/private key pair used to sign
27656 the store items being published.
27661 @subsubheading Laminar
27663 @uref{https://laminar.ohwg.net/, Laminar} is a lightweight and modular
27664 Continuous Integration service. It doesn't have a configuration web UI
27665 instead uses version-controllable configuration files and scripts.
27667 Laminar encourages the use of existing tools such as bash and cron
27668 instead of reinventing them.
27670 @defvr {Scheme Procedure} laminar-service-type
27671 The type of the Laminar service. Its value must be a
27672 @code{laminar-configuration} object, as described below.
27674 All configuration values have defaults, a minimal configuration to get
27675 Laminar running is shown below. By default, the web interface is
27676 available on port 8080.
27679 (service laminar-service-type)
27683 @deftp {Data Type} laminar-configuration
27684 Data type representing the configuration of Laminar.
27687 @item @code{laminar} (default: @code{laminar})
27688 The Laminar package to use.
27690 @item @code{home-directory} (default: @code{"/var/lib/laminar"})
27691 The directory for job configurations and run directories.
27693 @item @code{bind-http} (default: @code{"*:8080"})
27694 The interface/port or unix socket on which laminard should listen for
27695 incoming connections to the web frontend.
27697 @item @code{bind-rpc} (default: @code{"unix-abstract:laminar"})
27698 The interface/port or unix socket on which laminard should listen for
27699 incoming commands such as build triggers.
27701 @item @code{title} (default: @code{"Laminar"})
27702 The page title to show in the web frontend.
27704 @item @code{keep-rundirs} (default: @code{0})
27705 Set to an integer defining how many rundirs to keep per job. The
27706 lowest-numbered ones will be deleted. The default is 0, meaning all run
27707 dirs will be immediately deleted.
27709 @item @code{archive-url} (default: @code{#f})
27710 The web frontend served by laminard will use this URL to form links to
27711 artefacts archived jobs.
27713 @item @code{base-url} (default: @code{#f})
27714 Base URL to use for links to laminar itself.
27719 @node Power Management Services
27720 @subsection Power Management Services
27723 @cindex power management with TLP
27724 @subsubheading TLP daemon
27726 The @code{(gnu services pm)} module provides a Guix service definition
27727 for the Linux power management tool TLP.
27729 TLP enables various powersaving modes in userspace and kernel.
27730 Contrary to @code{upower-service}, it is not a passive,
27731 monitoring tool, as it will apply custom settings each time a new power
27732 source is detected. More information can be found at
27733 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
27735 @deffn {Scheme Variable} tlp-service-type
27736 The service type for the TLP tool. The default settings are optimised
27737 for battery life on most systems, but you can tweak them to your heart's
27738 content by adding a valid @code{tlp-configuration}:
27740 (service tlp-service-type
27742 (cpu-scaling-governor-on-ac (list "performance"))
27743 (sched-powersave-on-bat? #t)))
27747 Each parameter definition is preceded by its type; for example,
27748 @samp{boolean foo} indicates that the @code{foo} parameter
27749 should be specified as a boolean. Types starting with
27750 @code{maybe-} denote parameters that won't show up in TLP config file
27751 when their value is @code{'disabled}.
27753 @c The following documentation was initially generated by
27754 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
27755 @c documentation is better, so we shouldn't hesitate to edit below as
27756 @c needed. However if the change you want to make to this documentation
27757 @c can be done in an automated way, it's probably easier to change
27758 @c (generate-documentation) than to make it below and have to deal with
27759 @c the churn as TLP updates.
27761 Available @code{tlp-configuration} fields are:
27763 @deftypevr {@code{tlp-configuration} parameter} package tlp
27768 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
27769 Set to true if you wish to enable TLP.
27771 Defaults to @samp{#t}.
27775 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
27776 Default mode when no power supply can be detected. Alternatives are AC
27779 Defaults to @samp{"AC"}.
27783 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
27784 Number of seconds Linux kernel has to wait after the disk goes idle,
27785 before syncing on AC.
27787 Defaults to @samp{0}.
27791 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
27792 Same as @code{disk-idle-ac} but on BAT mode.
27794 Defaults to @samp{2}.
27798 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
27799 Dirty pages flushing periodicity, expressed in seconds.
27801 Defaults to @samp{15}.
27805 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
27806 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
27808 Defaults to @samp{60}.
27812 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
27813 CPU frequency scaling governor on AC mode. With intel_pstate driver,
27814 alternatives are powersave and performance. With acpi-cpufreq driver,
27815 alternatives are ondemand, powersave, performance and conservative.
27817 Defaults to @samp{disabled}.
27821 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
27822 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
27824 Defaults to @samp{disabled}.
27828 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
27829 Set the min available frequency for the scaling governor on AC.
27831 Defaults to @samp{disabled}.
27835 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
27836 Set the max available frequency for the scaling governor on AC.
27838 Defaults to @samp{disabled}.
27842 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
27843 Set the min available frequency for the scaling governor on BAT.
27845 Defaults to @samp{disabled}.
27849 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
27850 Set the max available frequency for the scaling governor on BAT.
27852 Defaults to @samp{disabled}.
27856 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
27857 Limit the min P-state to control the power dissipation of the CPU, in AC
27858 mode. Values are stated as a percentage of the available performance.
27860 Defaults to @samp{disabled}.
27864 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
27865 Limit the max P-state to control the power dissipation of the CPU, in AC
27866 mode. Values are stated as a percentage of the available performance.
27868 Defaults to @samp{disabled}.
27872 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
27873 Same as @code{cpu-min-perf-on-ac} on BAT mode.
27875 Defaults to @samp{disabled}.
27879 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
27880 Same as @code{cpu-max-perf-on-ac} on BAT mode.
27882 Defaults to @samp{disabled}.
27886 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
27887 Enable CPU turbo boost feature on AC mode.
27889 Defaults to @samp{disabled}.
27893 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
27894 Same as @code{cpu-boost-on-ac?} on BAT mode.
27896 Defaults to @samp{disabled}.
27900 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
27901 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
27902 used under light load conditions.
27904 Defaults to @samp{#f}.
27908 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
27909 Same as @code{sched-powersave-on-ac?} but on BAT mode.
27911 Defaults to @samp{#t}.
27915 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
27916 Enable Linux kernel NMI watchdog.
27918 Defaults to @samp{#f}.
27922 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
27923 For Linux kernels with PHC patch applied, change CPU voltages. An
27924 example value would be @samp{"F:V F:V F:V F:V"}.
27926 Defaults to @samp{disabled}.
27930 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
27931 Set CPU performance versus energy saving policy on AC@. Alternatives are
27932 performance, normal, powersave.
27934 Defaults to @samp{"performance"}.
27938 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
27939 Same as @code{energy-perf-policy-ac} but on BAT mode.
27941 Defaults to @samp{"powersave"}.
27945 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
27950 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
27951 Hard disk advanced power management level.
27955 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
27956 Same as @code{disk-apm-bat} but on BAT mode.
27960 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
27961 Hard disk spin down timeout. One value has to be specified for each
27962 declared hard disk.
27964 Defaults to @samp{disabled}.
27968 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
27969 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
27971 Defaults to @samp{disabled}.
27975 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
27976 Select IO scheduler for disk devices. One value has to be specified for
27977 each declared hard disk. Example alternatives are cfq, deadline and
27980 Defaults to @samp{disabled}.
27984 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
27985 SATA aggressive link power management (ALPM) level. Alternatives are
27986 min_power, medium_power, max_performance.
27988 Defaults to @samp{"max_performance"}.
27992 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
27993 Same as @code{sata-linkpwr-ac} but on BAT mode.
27995 Defaults to @samp{"min_power"}.
27999 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
28000 Exclude specified SATA host devices for link power management.
28002 Defaults to @samp{disabled}.
28006 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
28007 Enable Runtime Power Management for AHCI controller and disks on AC
28010 Defaults to @samp{disabled}.
28014 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
28015 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
28017 Defaults to @samp{disabled}.
28021 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
28022 Seconds of inactivity before disk is suspended.
28024 Defaults to @samp{15}.
28028 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
28029 PCI Express Active State Power Management level. Alternatives are
28030 default, performance, powersave.
28032 Defaults to @samp{"performance"}.
28036 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
28037 Same as @code{pcie-aspm-ac} but on BAT mode.
28039 Defaults to @samp{"powersave"}.
28043 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
28044 Radeon graphics clock speed level. Alternatives are low, mid, high,
28047 Defaults to @samp{"high"}.
28051 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
28052 Same as @code{radeon-power-ac} but on BAT mode.
28054 Defaults to @samp{"low"}.
28058 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
28059 Radeon dynamic power management method (DPM). Alternatives are battery,
28062 Defaults to @samp{"performance"}.
28066 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
28067 Same as @code{radeon-dpm-state-ac} but on BAT mode.
28069 Defaults to @samp{"battery"}.
28073 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
28074 Radeon DPM performance level. Alternatives are auto, low, high.
28076 Defaults to @samp{"auto"}.
28080 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
28081 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
28083 Defaults to @samp{"auto"}.
28087 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
28088 Wifi power saving mode.
28090 Defaults to @samp{#f}.
28094 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
28095 Same as @code{wifi-power-ac?} but on BAT mode.
28097 Defaults to @samp{#t}.
28101 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
28102 Disable wake on LAN.
28104 Defaults to @samp{#t}.
28108 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
28109 Timeout duration in seconds before activating audio power saving on
28110 Intel HDA and AC97 devices. A value of 0 disables power saving.
28112 Defaults to @samp{0}.
28116 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
28117 Same as @code{sound-powersave-ac} but on BAT mode.
28119 Defaults to @samp{1}.
28123 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
28124 Disable controller in powersaving mode on Intel HDA devices.
28126 Defaults to @samp{#t}.
28130 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
28131 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
28132 powered on again by releasing (and reinserting) the eject lever or by
28133 pressing the disc eject button on newer models.
28135 Defaults to @samp{#f}.
28139 @deftypevr {@code{tlp-configuration} parameter} string bay-device
28140 Name of the optical drive device to power off.
28142 Defaults to @samp{"sr0"}.
28146 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
28147 Runtime Power Management for PCI(e) bus devices. Alternatives are on
28150 Defaults to @samp{"on"}.
28154 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
28155 Same as @code{runtime-pm-ac} but on BAT mode.
28157 Defaults to @samp{"auto"}.
28161 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
28162 Runtime Power Management for all PCI(e) bus devices, except blacklisted
28165 Defaults to @samp{#t}.
28169 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
28170 Exclude specified PCI(e) device addresses from Runtime Power Management.
28172 Defaults to @samp{disabled}.
28176 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
28177 Exclude PCI(e) devices assigned to the specified drivers from Runtime
28182 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
28183 Enable USB autosuspend feature.
28185 Defaults to @samp{#t}.
28189 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
28190 Exclude specified devices from USB autosuspend.
28192 Defaults to @samp{disabled}.
28196 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
28197 Exclude WWAN devices from USB autosuspend.
28199 Defaults to @samp{#t}.
28203 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
28204 Include specified devices into USB autosuspend, even if they are already
28205 excluded by the driver or via @code{usb-blacklist-wwan?}.
28207 Defaults to @samp{disabled}.
28211 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
28212 Enable USB autosuspend before shutdown.
28214 Defaults to @samp{disabled}.
28218 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
28219 Restore radio device state (bluetooth, wifi, wwan) from previous
28220 shutdown on system startup.
28222 Defaults to @samp{#f}.
28227 @cindex CPU frequency scaling with thermald
28228 @subsubheading Thermald daemon
28230 The @code{(gnu services pm)} module provides an interface to
28231 thermald, a CPU frequency scaling service which helps prevent overheating.
28233 @defvr {Scheme Variable} thermald-service-type
28234 This is the service type for
28235 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
28236 Thermal Daemon, which is responsible for controlling the thermal state
28237 of processors and preventing overheating.
28240 @deftp {Data Type} thermald-configuration
28241 Data type representing the configuration of @code{thermald-service-type}.
28244 @item @code{ignore-cpuid-check?} (default: @code{#f})
28245 Ignore cpuid check for supported CPU models.
28247 @item @code{thermald} (default: @var{thermald})
28248 Package object of thermald.
28253 @node Audio Services
28254 @subsection Audio Services
28256 The @code{(gnu services audio)} module provides a service to start MPD
28257 (the Music Player Daemon).
28260 @subsubheading Music Player Daemon
28262 The Music Player Daemon (MPD) is a service that can play music while
28263 being controlled from the local machine or over the network by a variety
28266 The following example shows how one might run @code{mpd} as user
28267 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
28270 (service mpd-service-type
28276 @defvr {Scheme Variable} mpd-service-type
28277 The service type for @command{mpd}
28280 @deftp {Data Type} mpd-configuration
28281 Data type representing the configuration of @command{mpd}.
28284 @item @code{user} (default: @code{"mpd"})
28285 The user to run mpd as.
28287 @item @code{music-dir} (default: @code{"~/Music"})
28288 The directory to scan for music files.
28290 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
28291 The directory to store playlists.
28293 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
28294 The location of the music database.
28296 @item @code{state-file} (default: @code{"~/.mpd/state"})
28297 The location of the file that stores current MPD's state.
28299 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
28300 The location of the sticker database.
28302 @item @code{port} (default: @code{"6600"})
28303 The port to run mpd on.
28305 @item @code{address} (default: @code{"any"})
28306 The address that mpd will bind to. To use a Unix domain socket,
28307 an absolute path can be specified here.
28309 @item @code{outputs} (default: @code{"(list (mpd-output))"})
28310 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
28315 @deftp {Data Type} mpd-output
28316 Data type representing an @command{mpd} audio output.
28319 @item @code{name} (default: @code{"MPD"})
28320 The name of the audio output.
28322 @item @code{type} (default: @code{"pulse"})
28323 The type of audio output.
28325 @item @code{enabled?} (default: @code{#t})
28326 Specifies whether this audio output is enabled when MPD is started. By
28327 default, all audio outputs are enabled. This is just the default
28328 setting when there is no state file; with a state file, the previous
28331 @item @code{tags?} (default: @code{#t})
28332 If set to @code{#f}, then MPD will not send tags to this output. This
28333 is only useful for output plugins that can receive tags, for example the
28334 @code{httpd} output plugin.
28336 @item @code{always-on?} (default: @code{#f})
28337 If set to @code{#t}, then MPD attempts to keep this audio output always
28338 open. This may be useful for streaming servers, when you don’t want to
28339 disconnect all listeners even when playback is accidentally stopped.
28341 @item @code{mixer-type}
28342 This field accepts a symbol that specifies which mixer should be used
28343 for this audio output: the @code{hardware} mixer, the @code{software}
28344 mixer, the @code{null} mixer (allows setting the volume, but with no
28345 effect; this can be used as a trick to implement an external mixer
28346 External Mixer) or no mixer (@code{none}).
28348 @item @code{extra-options} (default: @code{'()})
28349 An association list of option symbols to string values to be appended to
28350 the audio output configuration.
28355 The following example shows a configuration of @code{mpd} that provides
28356 an HTTP audio streaming output.
28359 (service mpd-service-type
28367 `((encoder . "vorbis")
28368 (port . "8080"))))))))
28372 @node Virtualization Services
28373 @subsection Virtualization Services
28375 The @code{(gnu services virtualization)} module provides services for
28376 the libvirt and virtlog daemons, as well as other virtualization-related
28379 @subsubheading Libvirt daemon
28381 @code{libvirtd} is the server side daemon component of the libvirt
28382 virtualization management system. This daemon runs on host servers
28383 and performs required management tasks for virtualized guests.
28385 @deffn {Scheme Variable} libvirt-service-type
28386 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
28387 Its value must be a @code{libvirt-configuration}.
28390 (service libvirt-service-type
28391 (libvirt-configuration
28392 (unix-sock-group "libvirt")
28393 (tls-port "16555")))
28397 @c Auto-generated with (generate-libvirt-documentation)
28398 Available @code{libvirt-configuration} fields are:
28400 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
28405 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
28406 Flag listening for secure TLS connections on the public TCP/IP port.
28407 You must set @code{listen} for this to have any effect.
28409 It is necessary to setup a CA and issue server certificates before using
28412 Defaults to @samp{#t}.
28416 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
28417 Listen for unencrypted TCP connections on the public TCP/IP port. You must
28418 set @code{listen} for this to have any effect.
28420 Using the TCP socket requires SASL authentication by default. Only SASL
28421 mechanisms which support data encryption are allowed. This is
28422 DIGEST_MD5 and GSSAPI (Kerberos5).
28424 Defaults to @samp{#f}.
28428 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
28429 Port for accepting secure TLS connections. This can be a port number,
28432 Defaults to @samp{"16514"}.
28436 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
28437 Port for accepting insecure TCP connections. This can be a port number,
28440 Defaults to @samp{"16509"}.
28444 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
28445 IP address or hostname used for client connections.
28447 Defaults to @samp{"0.0.0.0"}.
28451 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
28452 Flag toggling mDNS advertisement of the libvirt service.
28454 Alternatively can disable for all services on a host by stopping the
28457 Defaults to @samp{#f}.
28461 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
28462 Default mDNS advertisement name. This must be unique on the immediate
28465 Defaults to @samp{"Virtualization Host <hostname>"}.
28469 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
28470 UNIX domain socket group ownership. This can be used to allow a
28471 'trusted' set of users access to management capabilities without
28474 Defaults to @samp{"root"}.
28478 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
28479 UNIX socket permissions for the R/O socket. This is used for monitoring
28482 Defaults to @samp{"0777"}.
28486 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
28487 UNIX socket permissions for the R/W socket. Default allows only root.
28488 If PolicyKit is enabled on the socket, the default will change to allow
28489 everyone (eg, 0777)
28491 Defaults to @samp{"0770"}.
28495 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
28496 UNIX socket permissions for the admin socket. Default allows only owner
28497 (root), do not change it unless you are sure to whom you are exposing
28500 Defaults to @samp{"0777"}.
28504 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
28505 The directory in which sockets will be found/created.
28507 Defaults to @samp{"/var/run/libvirt"}.
28511 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
28512 Authentication scheme for UNIX read-only sockets. By default socket
28513 permissions allow anyone to connect
28515 Defaults to @samp{"polkit"}.
28519 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
28520 Authentication scheme for UNIX read-write sockets. By default socket
28521 permissions only allow root. If PolicyKit support was compiled into
28522 libvirt, the default will be to use 'polkit' auth.
28524 Defaults to @samp{"polkit"}.
28528 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
28529 Authentication scheme for TCP sockets. If you don't enable SASL, then
28530 all TCP traffic is cleartext. Don't do this outside of a dev/test
28533 Defaults to @samp{"sasl"}.
28537 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
28538 Authentication scheme for TLS sockets. TLS sockets already have
28539 encryption provided by the TLS layer, and limited authentication is done
28542 It is possible to make use of any SASL authentication mechanism as well,
28543 by using 'sasl' for this option
28545 Defaults to @samp{"none"}.
28549 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
28550 API access control scheme.
28552 By default an authenticated user is allowed access to all APIs. Access
28553 drivers can place restrictions on this.
28555 Defaults to @samp{()}.
28559 @deftypevr {@code{libvirt-configuration} parameter} string key-file
28560 Server key file path. If set to an empty string, then no private key is
28563 Defaults to @samp{""}.
28567 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
28568 Server key file path. If set to an empty string, then no certificate is
28571 Defaults to @samp{""}.
28575 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
28576 Server key file path. If set to an empty string, then no CA certificate
28579 Defaults to @samp{""}.
28583 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
28584 Certificate revocation list path. If set to an empty string, then no
28587 Defaults to @samp{""}.
28591 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
28592 Disable verification of our own server certificates.
28594 When libvirtd starts it performs some sanity checks against its own
28597 Defaults to @samp{#f}.
28601 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
28602 Disable verification of client certificates.
28604 Client certificate verification is the primary authentication mechanism.
28605 Any client which does not present a certificate signed by the CA will be
28608 Defaults to @samp{#f}.
28612 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
28613 Whitelist of allowed x509 Distinguished Name.
28615 Defaults to @samp{()}.
28619 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
28620 Whitelist of allowed SASL usernames. The format for username depends on
28621 the SASL authentication mechanism.
28623 Defaults to @samp{()}.
28627 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
28628 Override the compile time default TLS priority string. The default is
28629 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
28630 is desired for libvirt to deviate from the global default settings.
28632 Defaults to @samp{"NORMAL"}.
28636 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
28637 Maximum number of concurrent client connections to allow over all
28640 Defaults to @samp{5000}.
28644 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
28645 Maximum length of queue of connections waiting to be accepted by the
28646 daemon. Note, that some protocols supporting retransmission may obey
28647 this so that a later reattempt at connection succeeds.
28649 Defaults to @samp{1000}.
28653 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
28654 Maximum length of queue of accepted but not yet authenticated clients.
28655 Set this to zero to turn this feature off
28657 Defaults to @samp{20}.
28661 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
28662 Number of workers to start up initially.
28664 Defaults to @samp{5}.
28668 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
28669 Maximum number of worker threads.
28671 If the number of active clients exceeds @code{min-workers}, then more
28672 threads are spawned, up to max_workers limit. Typically you'd want
28673 max_workers to equal maximum number of clients allowed.
28675 Defaults to @samp{20}.
28679 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
28680 Number of priority workers. If all workers from above pool are stuck,
28681 some calls marked as high priority (notably domainDestroy) can be
28682 executed in this pool.
28684 Defaults to @samp{5}.
28688 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
28689 Total global limit on concurrent RPC calls.
28691 Defaults to @samp{20}.
28695 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
28696 Limit on concurrent requests from a single client connection. To avoid
28697 one client monopolizing the server this should be a small fraction of
28698 the global max_requests and max_workers parameter.
28700 Defaults to @samp{5}.
28704 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
28705 Same as @code{min-workers} but for the admin interface.
28707 Defaults to @samp{1}.
28711 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
28712 Same as @code{max-workers} but for the admin interface.
28714 Defaults to @samp{5}.
28718 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
28719 Same as @code{max-clients} but for the admin interface.
28721 Defaults to @samp{5}.
28725 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
28726 Same as @code{max-queued-clients} but for the admin interface.
28728 Defaults to @samp{5}.
28732 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
28733 Same as @code{max-client-requests} but for the admin interface.
28735 Defaults to @samp{5}.
28739 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
28740 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28742 Defaults to @samp{3}.
28746 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
28749 A filter allows to select a different logging level for a given category
28750 of logs. The format for a filter is one of:
28761 where @code{name} is a string which is matched against the category
28762 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28763 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
28764 name in the filter can be a substring of the full category name, in
28765 order to match multiple similar categories), the optional @samp{"+"}
28766 prefix tells libvirt to log stack trace for each message matching name,
28767 and @code{x} is the minimal level where matching messages should be
28785 Multiple filters can be defined in a single filters statement, they just
28786 need to be separated by spaces.
28788 Defaults to @samp{"3:remote 4:event"}.
28792 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
28795 An output is one of the places to save logging information. The format
28796 for an output can be:
28800 output goes to stderr
28802 @item x:syslog:name
28803 use syslog for the output and use the given name as the ident
28805 @item x:file:file_path
28806 output to a file, with the given filepath
28809 output to journald logging system
28813 In all case the x prefix is the minimal level, acting as a filter
28830 Multiple outputs can be defined, they just need to be separated by
28833 Defaults to @samp{"3:stderr"}.
28837 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
28838 Allows usage of the auditing subsystem to be altered
28842 0: disable all auditing
28845 1: enable auditing, only if enabled on host
28848 2: enable auditing, and exit if disabled on host.
28852 Defaults to @samp{1}.
28856 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
28857 Send audit messages via libvirt logging infrastructure.
28859 Defaults to @samp{#f}.
28863 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
28864 Host UUID@. UUID must not have all digits be the same.
28866 Defaults to @samp{""}.
28870 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
28871 Source to read host UUID.
28875 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
28878 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
28882 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
28885 Defaults to @samp{"smbios"}.
28889 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
28890 A keepalive message is sent to a client after @code{keepalive_interval}
28891 seconds of inactivity to check if the client is still responding. If
28892 set to -1, libvirtd will never send keepalive requests; however clients
28893 can still send them and the daemon will send responses.
28895 Defaults to @samp{5}.
28899 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
28900 Maximum number of keepalive messages that are allowed to be sent to the
28901 client without getting any response before the connection is considered
28904 In other words, the connection is automatically closed approximately
28905 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
28906 the last message received from the client. When @code{keepalive-count}
28907 is set to 0, connections will be automatically closed after
28908 @code{keepalive-interval} seconds of inactivity without sending any
28909 keepalive messages.
28911 Defaults to @samp{5}.
28915 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
28916 Same as above but for admin interface.
28918 Defaults to @samp{5}.
28922 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
28923 Same as above but for admin interface.
28925 Defaults to @samp{5}.
28929 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
28930 Timeout for Open vSwitch calls.
28932 The @code{ovs-vsctl} utility is used for the configuration and its
28933 timeout option is set by default to 5 seconds to avoid potential
28934 infinite waits blocking libvirt.
28936 Defaults to @samp{5}.
28940 @c %end of autogenerated docs
28942 @subsubheading Virtlog daemon
28943 The virtlogd service is a server side daemon component of libvirt that is
28944 used to manage logs from virtual machine consoles.
28946 This daemon is not used directly by libvirt client applications, rather it
28947 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
28948 standalone daemon, the main @code{libvirtd} daemon can be restarted without
28949 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
28950 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
28952 @deffn {Scheme Variable} virtlog-service-type
28953 This is the type of the virtlog daemon.
28954 Its value must be a @code{virtlog-configuration}.
28957 (service virtlog-service-type
28958 (virtlog-configuration
28959 (max-clients 1000)))
28963 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
28964 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28966 Defaults to @samp{3}.
28970 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
28973 A filter allows to select a different logging level for a given category
28974 of logs The format for a filter is one of:
28985 where @code{name} is a string which is matched against the category
28986 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28987 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
28988 be a substring of the full category name, in order to match multiple
28989 similar categories), the optional "+" prefix tells libvirt to log stack
28990 trace for each message matching name, and @code{x} is the minimal level
28991 where matching messages should be logged:
29008 Multiple filters can be defined in a single filters statement, they just
29009 need to be separated by spaces.
29011 Defaults to @samp{"3:remote 4:event"}.
29015 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
29018 An output is one of the places to save logging information The format
29019 for an output can be:
29023 output goes to stderr
29025 @item x:syslog:name
29026 use syslog for the output and use the given name as the ident
29028 @item x:file:file_path
29029 output to a file, with the given filepath
29032 output to journald logging system
29036 In all case the x prefix is the minimal level, acting as a filter
29053 Multiple outputs can be defined, they just need to be separated by
29056 Defaults to @samp{"3:stderr"}.
29060 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
29061 Maximum number of concurrent client connections to allow over all
29064 Defaults to @samp{1024}.
29068 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
29069 Maximum file size before rolling over.
29071 Defaults to @samp{2MB}
29075 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
29076 Maximum number of backup files to keep.
29078 Defaults to @samp{3}
29082 @anchor{transparent-emulation-qemu}
29083 @subsubheading Transparent Emulation with QEMU
29086 @cindex @code{binfmt_misc}
29087 @code{qemu-binfmt-service-type} provides support for transparent
29088 emulation of program binaries built for different architectures---e.g.,
29089 it allows you to transparently execute an ARMv7 program on an x86_64
29090 machine. It achieves this by combining the @uref{https://www.qemu.org,
29091 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
29092 This feature only allows you to emulate GNU/Linux on a different
29093 architecture, but see below for GNU/Hurd support.
29095 @defvr {Scheme Variable} qemu-binfmt-service-type
29096 This is the type of the QEMU/binfmt service for transparent emulation.
29097 Its value must be a @code{qemu-binfmt-configuration} object, which
29098 specifies the QEMU package to use as well as the architecture we want to
29102 (service qemu-binfmt-service-type
29103 (qemu-binfmt-configuration
29104 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
29107 In this example, we enable transparent emulation for the ARM and aarch64
29108 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
29109 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
29110 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
29113 @deftp {Data Type} qemu-binfmt-configuration
29114 This is the configuration for the @code{qemu-binfmt} service.
29117 @item @code{platforms} (default: @code{'()})
29118 The list of emulated QEMU platforms. Each item must be a @dfn{platform
29119 object} as returned by @code{lookup-qemu-platforms} (see below).
29121 For example, let's suppose you're on an x86_64 machine and you have this
29125 (service qemu-binfmt-service-type
29126 (qemu-binfmt-configuration
29127 (platforms (lookup-qemu-platforms "arm"))))
29133 guix build -s armhf-linux inkscape
29137 and it will build Inkscape for ARMv7 @emph{as if it were a native
29138 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
29139 if you'd like to test a package build for an architecture you don't have
29142 @item @code{qemu} (default: @code{qemu})
29143 The QEMU package to use.
29147 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
29148 Return the list of QEMU platform objects corresponding to
29149 @var{platforms}@dots{}. @var{platforms} must be a list of strings
29150 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
29151 @code{"mips64el"}, and so on.
29154 @deffn {Scheme Procedure} qemu-platform? @var{obj}
29155 Return true if @var{obj} is a platform object.
29158 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
29159 Return the name of @var{platform}---a string such as @code{"arm"}.
29163 @subsubheading The Hurd in a Virtual Machine
29165 @cindex @code{hurd}
29169 Service @code{hurd-vm} provides support for running GNU/Hurd in a
29170 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
29171 to be used on GNU/Linux and the given GNU/Hurd operating system
29172 configuration is cross-compiled. The virtual machine is a Shepherd
29173 service that can be referred to by the names @code{hurd-vm} and
29174 @code{childhurd} and be controlled with commands such as:
29178 herd stop childhurd
29181 When the service is running, you can view its console by connecting to
29182 it with a VNC client, for example with:
29185 guix environment --ad-hoc tigervnc-client -- \
29186 vncviewer localhost:5900
29189 The default configuration (see @code{hurd-vm-configuration} below)
29190 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
29191 (the virtual machine emulator) redirects to port 10222 on the host.
29192 Thus, you can connect over SSH to the childhurd with:
29195 ssh root@@localhost -p 10022
29198 The childhurd is volatile and stateless: it starts with a fresh root
29199 file system every time you restart it. By default though, all the files
29200 under @file{/etc/childhurd} on the host are copied as is to the root
29201 file system of the childhurd when it boots. This allows you to
29202 initialize ``secrets'' inside the VM: SSH host keys, authorized
29203 substitute keys, and so on---see the explanation of @code{secret-root}
29206 @defvr {Scheme Variable} hurd-vm-service-type
29207 This is the type of the Hurd in a Virtual Machine service. Its value
29208 must be a @code{hurd-vm-configuration} object, which specifies the
29209 operating system (@pxref{operating-system Reference}) and the disk size
29210 for the Hurd Virtual Machine, the QEMU package to use as well as the
29211 options for running it.
29216 (service hurd-vm-service-type
29217 (hurd-vm-configuration
29218 (disk-size (* 5000 (expt 2 20))) ;5G
29219 (memory-size 1024))) ;1024MiB
29222 would create a disk image big enough to build GNU@tie{}Hello, with some
29226 @deftp {Data Type} hurd-vm-configuration
29227 The data type representing the configuration for
29228 @code{hurd-vm-service-type}.
29231 @item @code{os} (default: @var{%hurd-vm-operating-system})
29232 The operating system to instantiate. This default is bare-bones with a
29233 permissive OpenSSH secure shell daemon listening on port 2222
29234 (@pxref{Networking Services, @code{openssh-service-type}}).
29236 @item @code{qemu} (default: @code{qemu-minimal})
29237 The QEMU package to use.
29239 @item @code{image} (default: @var{hurd-vm-disk-image})
29240 The procedure used to build the disk-image built from this
29243 @item @code{disk-size} (default: @code{'guess})
29244 The size of the disk image.
29246 @item @code{memory-size} (default: @code{512})
29247 The memory size of the Virtual Machine in mebibytes.
29249 @item @code{options} (default: @code{'("--snapshot")})
29250 The extra options for running QEMU.
29252 @item @code{id} (default: @code{#f})
29253 If set, a non-zero positive integer used to parameterize Childhurd
29254 instances. It is appended to the service's name,
29255 e.g. @code{childhurd1}.
29257 @item @code{net-options} (default: @var{hurd-vm-net-options})
29258 The procedure used to produce the list of QEMU networking options.
29260 By default, it produces
29263 '("--device" "rtl8139,netdev=net0"
29264 "--netdev" (string-append
29266 "hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004,"
29267 "hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222,"
29268 "hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900"))
29271 with forwarded ports:
29274 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
29275 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
29276 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
29279 @item @code{secret-root} (default: @file{/etc/childhurd})
29280 The root directory with out-of-band secrets to be installed into the
29281 childhurd once it runs. Childhurds are volatile which means that on
29282 every startup, secrets such as the SSH host keys and Guix signing key
29285 If the @file{/etc/childhurd} directory does not exist, the
29286 @code{secret-service} running in the Childhurd will be sent an empty
29289 By default, the service automatically populates @file{/etc/childhurd}
29290 with the following non-volatile secrets, unless they already exist:
29293 /etc/childhurd/etc/guix/acl
29294 /etc/childhurd/etc/guix/signing-key.pub
29295 /etc/childhurd/etc/guix/signing-key.sec
29296 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
29297 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
29298 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
29299 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
29302 These files are automatically sent to the guest Hurd VM when it boots,
29303 including permissions.
29305 @cindex childhurd, offloading
29306 @cindex Hurd, offloading
29307 Having these files in place means that only a couple of things are
29308 missing to allow the host to offload @code{i586-gnu} builds to the
29313 Authorizing the childhurd's key on the host so that the host accepts
29314 build results coming from the childhurd, which can be done like so:
29317 guix archive --authorize < \
29318 /etc/childhurd/etc/guix/signing-key.pub
29322 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
29326 We're working towards making that happen automatically---get in touch
29327 with us at @email{guix-devel@@gnu.org} to discuss it!
29331 Note that by default the VM image is volatile, i.e., once stopped the
29332 contents are lost. If you want a stateful image instead, override the
29333 configuration's @code{image} and @code{options} without
29334 the @code{--snapshot} flag using something along these lines:
29337 (service hurd-vm-service-type
29338 (hurd-vm-configuration
29339 (image (const "/out/of/store/writable/hurd.img"))
29343 @subsubheading Ganeti
29348 This service is considered experimental. Configuration options may be changed
29349 in a backwards-incompatible manner, and not all features have been thorougly
29350 tested. Users of this service are encouraged to share their experience at
29351 @email{guix-devel@@gnu.org}.
29354 Ganeti is a virtual machine management system. It is designed to keep virtual
29355 machines running on a cluster of servers even in the event of hardware failures,
29356 and to make maintenance and recovery tasks easy. It consists of multiple
29357 services which are described later in this section. In addition to the Ganeti
29358 service, you will need the OpenSSH service (@pxref{Networking Services,
29359 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
29360 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
29361 and address (or use a DNS server).
29363 All nodes participating in a Ganeti cluster should have the same Ganeti and
29364 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
29365 cluster node that supports multiple storage backends, and installs the
29366 @code{debootstrap} and @code{guix} @dfn{OS providers}:
29369 (use-package-modules virtualization)
29370 (use-service-modules base ganeti networking ssh)
29373 (host-name "node1")
29374 (hosts-file (plain-file "hosts" (format #f "
29375 127.0.0.1 localhost
29378 192.168.1.200 ganeti.example.com
29379 192.168.1.201 node1.example.com node1
29380 192.168.1.202 node2.example.com node2
29383 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
29384 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
29385 (packages (append (map specification->package
29386 '("qemu" "lvm2" "drbd-utils" "ceph"
29387 ;; Add the debootstrap and guix OS providers.
29388 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
29391 (append (list (static-networking-service "eth0" "192.168.1.201"
29392 #:netmask "255.255.255.0"
29393 #:gateway "192.168.1.254"
29394 #:name-servers '("192.168.1.252"
29397 ;; Ganeti uses SSH to communicate between nodes.
29398 (service openssh-service-type
29399 (openssh-configuration
29400 (permit-root-login 'prohibit-password)))
29402 (service ganeti-service-type
29403 (ganeti-configuration
29404 ;; This list specifies allowed file system paths
29405 ;; for storing virtual machine images.
29406 (file-storage-paths '("/srv/ganeti/file-storage"))
29407 ;; This variable configures a single "variant" for
29408 ;; both Debootstrap and Guix that works with KVM.
29409 (os %default-ganeti-os))))
29413 Users are advised to read the
29414 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
29415 administrators guide} to learn about the various cluster options and
29416 day-to-day operations. There is also a
29417 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
29418 describing how to configure and initialize a small cluster.
29420 @defvr {Scheme Variable} ganeti-service-type
29421 This is a service type that includes all the various services that Ganeti
29424 Its value is a @code{ganeti-configuration} object that defines the package
29425 to use for CLI operations, as well as configuration for the various daemons.
29426 Allowed file storage paths and available guest operating systems are also
29427 configured through this data type.
29430 @deftp {Data Type} ganeti-configuration
29431 The @code{ganeti} service takes the following configuration options:
29434 @item @code{ganeti} (default: @code{ganeti})
29435 The @code{ganeti} package to use. It will be installed to the system profile
29436 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
29437 that the value specified here does not affect the other services as each refer
29438 to a specific @code{ganeti} package (see below).
29440 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
29441 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
29442 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
29443 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
29444 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
29445 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
29446 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
29447 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
29448 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
29449 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
29451 These options control the various daemons and cron jobs that are distributed
29452 with Ganeti. The possible values for these are described in detail below.
29453 To override a setting, you must use the configuration type for that service:
29456 (service ganeti-service-type
29457 (ganeti-configuration
29458 (rapi-configuration
29459 (ganeti-rapi-configuration
29460 (interface "eth1"))))
29461 (watcher-configuration
29462 (ganeti-watcher-configuration
29463 (rapi-ip "10.0.0.1"))))
29466 @item @code{file-storage-paths} (default: @code{'()})
29467 List of allowed directories for file storage backend.
29469 @item @code{os} (default: @code{%default-ganeti-os})
29470 List of @code{<ganeti-os>} records.
29473 In essence @code{ganeti-service-type} is shorthand for declaring each service
29477 (service ganeti-noded-service-type)
29478 (service ganeti-confd-service-type)
29479 (service ganeti-wconfd-service-type)
29480 (service ganeti-luxid-service-type)
29481 (service ganeti-kvmd-service-type)
29482 (service ganeti-mond-service-type)
29483 (service ganeti-metad-service-type)
29484 (service ganeti-watcher-service-type)
29485 (service ganeti-cleaner-service-type)
29488 Plus a service extension for @code{etc-service-type} that configures the file
29489 storage backend and OS variants.
29493 @deftp {Data Type} ganeti-os
29494 This data type is suitable for passing to the @code{os} parameter of
29495 @code{ganeti-configuration}. It takes the following parameters:
29499 The name for this OS provider. It is only used to specify where the
29500 configuration ends up. Setting it to ``debootstrap'' will create
29501 @file{/etc/ganeti/instance-debootstrap}.
29503 @item @code{extension}
29504 The file extension for variants of this OS type. For example
29505 @file{.conf} or @file{.scm}.
29507 @item @code{variants} (default: @code{'()})
29508 List of @code{ganeti-os-variant} objects for this OS.
29513 @deftp {Data Type} ganeti-os-variant
29514 This is the data type for a Ganeti OS variant. It takes the following
29519 The name of this variant.
29521 @item @code{configuration}
29522 A configuration file for this variant.
29526 @defvr {Scheme Variable} %default-debootstrap-hooks
29527 This variable contains hooks to configure networking and the GRUB bootloader.
29530 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
29531 This variable contains a list of packages suitable for a fully-virtualized guest.
29534 @deftp {Data Type} debootstrap-configuration
29536 This data type creates configuration files suitable for the debootstrap OS provider.
29539 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
29540 When not @code{#f}, this must be a G-expression that specifies a directory with
29541 scripts that will run when the OS is installed. It can also be a list of
29542 @code{(name . file-like)} pairs. For example:
29545 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
29548 That will create a directory with one executable named @code{99-hello-world}
29549 and run it every time this variant is installed. If set to @code{#f}, hooks
29550 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
29551 @item @code{proxy} (default: @code{#f})
29552 Optional HTTP proxy to use.
29553 @item @code{mirror} (default: @code{#f})
29554 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
29555 The default varies depending on the distribution.
29556 @item @code{arch} (default: @code{#f})
29557 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
29558 on an AArch64 host. Default is to use the current system architecture.
29559 @item @code{suite} (default: @code{"stable"})
29560 When set, this must be a Debian distribution ``suite'' such as @code{buster}
29561 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
29562 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
29563 List of extra packages that will get installed by dpkg in addition
29564 to the minimal system.
29565 @item @code{components} (default: @code{#f})
29566 When set, must be a list of Debian repository ``components''. For example
29567 @code{'("main" "contrib")}.
29568 @item @code{generate-cache?} (default: @code{#t})
29569 Whether to automatically cache the generated debootstrap archive.
29570 @item @code{clean-cache} (default: @code{14})
29571 Discard the cache after this amount of days. Use @code{#f} to never
29573 @item @code{partition-style} (default: @code{'msdos})
29574 The type of partition to create. When set, it must be one of
29575 @code{'msdos}, @code{'none} or a string.
29576 @item @code{partition-alignment} (default: @code{2048})
29577 Alignment of the partition in sectors.
29581 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
29582 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
29583 takes two parameters: a name and a @code{debootstrap-configuration} object.
29586 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
29587 This is a helper procedure that creates a @code{ganeti-os} record. It takes
29588 a list of variants created with @code{debootstrap-variant}.
29591 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
29592 This is a helper procedure that creates a @code{ganeti-os-variant} record for
29593 use with the Guix OS provider. It takes a name and a G-expression that returns
29594 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
29595 Guix System configuration.
29598 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
29599 This is a helper procedure that creates a @code{ganeti-os} record. It
29600 takes a list of variants produced by @code{guix-variant}.
29603 @defvr {Scheme Variable} %default-debootstrap-variants
29604 This is a convenience variable to make the debootstrap provider work
29605 ``out of the box'' without users having to declare variants manually. It
29606 contains a single debootstrap variant with the default configuration:
29609 (list (debootstrap-variant
29611 (debootstrap-configuration)))
29615 @defvr {Scheme Variable} %default-guix-variants
29616 This is a convenience variable to make the Guix OS provider work without
29617 additional configuration. It creates a virtual machine that has an SSH
29618 server, a serial console, and authorizes the Ganeti hosts SSH keys.
29621 (list (guix-variant
29623 (file-append ganeti-instance-guix
29624 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
29628 Users can implement support for OS providers unbeknownst to Guix by extending
29629 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
29635 (extension ".conf")
29637 (list (ganeti-os-variant
29639 (configuration (plain-file "bar" "this is fine"))))))
29642 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
29643 to a file in the store with contents @code{this is fine}. It also creates
29644 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
29646 Obviously this may not work for all OS providers out there. If you find the
29647 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
29649 The rest of this section documents the various services that are included by
29650 @code{ganeti-service-type}.
29652 @defvr {Scheme Variable} ganeti-noded-service-type
29653 @command{ganeti-noded} is the daemon responsible for node-specific functions
29654 within the Ganeti system. The value of this service must be a
29655 @code{ganeti-noded-configuration} object.
29658 @deftp {Data Type} ganeti-noded-configuration
29659 This is the configuration for the @code{ganeti-noded} service.
29662 @item @code{ganeti} (default: @code{ganeti})
29663 The @code{ganeti} package to use for this service.
29665 @item @code{port} (default: @code{1811})
29666 The TCP port on which the node daemon listens for network requests.
29668 @item @code{address} (default: @code{"0.0.0.0"})
29669 The network address that the daemon will bind to. The default address means
29670 bind to all available addresses.
29672 @item @code{interface} (default: @code{#f})
29673 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
29674 that the daemon will bind to.
29676 @item @code{max-clients} (default: @code{20})
29677 This sets a limit on the maximum number of simultaneous client connections
29678 that the daemon will handle. Connections above this count are accepted, but
29679 no responses will be sent until enough connections have closed.
29681 @item @code{ssl?} (default: @code{#t})
29682 Whether to use SSL/TLS to encrypt network communications. The certificate
29683 is automatically provisioned by the cluster and can be rotated with
29684 @command{gnt-cluster renew-crypto}.
29686 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29687 This can be used to provide a specific encryption key for TLS communications.
29689 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29690 This can be used to provide a specific certificate for TLS communications.
29692 @item @code{debug?} (default: @code{#f})
29693 When true, the daemon performs additional logging for debugging purposes.
29694 Note that this will leak encryption details to the log files, use with caution.
29699 @defvr {Scheme Variable} ganeti-confd-service-type
29700 @command{ganeti-confd} answers queries related to the configuration of a
29701 Ganeti cluster. The purpose of this daemon is to have a highly available
29702 and fast way to query cluster configuration values. It is automatically
29703 active on all @dfn{master candidates}. The value of this service must be a
29704 @code{ganeti-confd-configuration} object.
29708 @deftp {Data Type} ganeti-confd-configuration
29709 This is the configuration for the @code{ganeti-confd} service.
29712 @item @code{ganeti} (default: @code{ganeti})
29713 The @code{ganeti} package to use for this service.
29715 @item @code{port} (default: @code{1814})
29716 The UDP port on which to listen for network requests.
29718 @item @code{address} (default: @code{"0.0.0.0"})
29719 Network address that the daemon will bind to.
29721 @item @code{debug?} (default: @code{#f})
29722 When true, the daemon performs additional logging for debugging purposes.
29727 @defvr {Scheme Variable} ganeti-wconfd-service-type
29728 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
29729 about the cluster configuration and is the only entity that can accept
29730 changes to it. All jobs that need to modify the configuration will do so
29731 by sending appropriate requests to this daemon. It only runs on the
29732 @dfn{master node} and will automatically disable itself on other nodes.
29734 The value of this service must be a
29735 @code{ganeti-wconfd-configuration} object.
29738 @deftp {Data Type} ganeti-wconfd-configuration
29739 This is the configuration for the @code{ganeti-wconfd} service.
29742 @item @code{ganeti} (default: @code{ganeti})
29743 The @code{ganeti} package to use for this service.
29745 @item @code{no-voting?} (default: @code{#f})
29746 The daemon will refuse to start if the majority of cluster nodes does not
29747 agree that it is running on the master node. Set to @code{#t} to start
29748 even if a quorum can not be reached (dangerous, use with caution).
29750 @item @code{debug?} (default: @code{#f})
29751 When true, the daemon performs additional logging for debugging purposes.
29756 @defvr {Scheme Variable} ganeti-luxid-service-type
29757 @command{ganeti-luxid} is a daemon used to answer queries related to the
29758 configuration and the current live state of a Ganeti cluster. Additionally,
29759 it is the authoritative daemon for the Ganeti job queue. Jobs can be
29760 submitted via this daemon and it schedules and starts them.
29762 It takes a @code{ganeti-luxid-configuration} object.
29765 @deftp {Data Type} ganeti-luxid-configuration
29766 This is the configuration for the @code{ganeti-wconfd} service.
29769 @item @code{ganeti} (default: @code{ganeti})
29770 The @code{ganeti} package to use for this service.
29772 @item @code{no-voting?} (default: @code{#f})
29773 The daemon will refuse to start if it cannot verify that the majority of
29774 cluster nodes believes that it is running on the master node. Set to
29775 @code{#t} to ignore such checks and start anyway (this can be dangerous).
29777 @item @code{debug?} (default: @code{#f})
29778 When true, the daemon performs additional logging for debugging purposes.
29783 @defvr {Scheme Variable} ganeti-rapi-service-type
29784 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
29785 the master node and can be used to perform cluster actions programmatically
29786 via a JSON-based RPC protocol.
29788 Most query operations are allowed without authentication (unless
29789 @var{require-authentication?} is set), whereas write operations require
29790 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
29791 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
29792 API documentation} for more information.
29794 The value of this service must be a @code{ganeti-rapi-configuration} object.
29797 @deftp {Data Type} ganeti-rapi-configuration
29798 This is the configuration for the @code{ganeti-rapi} service.
29801 @item @code{ganeti} (default: @code{ganeti})
29802 The @code{ganeti} package to use for this service.
29804 @item @code{require-authentication?} (default: @code{#f})
29805 Whether to require authentication even for read-only operations.
29807 @item @code{port} (default: @code{5080})
29808 The TCP port on which to listen to API requests.
29810 @item @code{address} (default: @code{"0.0.0.0"})
29811 The network address that the service will bind to. By default it listens
29812 on all configured addresses.
29814 @item @code{interface} (default: @code{#f})
29815 When set, it must specify a specific network interface such as @code{eth0}
29816 that the daemon will bind to.
29818 @item @code{max-clients} (default: @code{20})
29819 The maximum number of simultaneous client requests to handle. Further
29820 connections are allowed, but no responses are sent until enough connections
29823 @item @code{ssl?} (default: @code{#t})
29824 Whether to use SSL/TLS encryption on the RAPI port.
29826 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29827 This can be used to provide a specific encryption key for TLS communications.
29829 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29830 This can be used to provide a specific certificate for TLS communications.
29832 @item @code{debug?} (default: @code{#f})
29833 When true, the daemon performs additional logging for debugging purposes.
29834 Note that this will leak encryption details to the log files, use with caution.
29839 @defvr {Scheme Variable} ganeti-kvmd-service-type
29840 @command{ganeti-kvmd} is responsible for determining whether a given KVM
29841 instance was shut down by an administrator or a user. Normally Ganeti will
29842 restart an instance that was not stopped through Ganeti itself. If the
29843 cluster option @code{user_shutdown} is true, this daemon monitors the
29844 @code{QMP} socket provided by QEMU and listens for shutdown events, and
29845 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
29846 it shuts down gracefully by itself.
29848 It takes a @code{ganeti-kvmd-configuration} object.
29851 @deftp {Data Type} ganeti-kvmd-configuration
29854 @item @code{ganeti} (default: @code{ganeti})
29855 The @code{ganeti} package to use for this service.
29857 @item @code{debug?} (default: @code{#f})
29858 When true, the daemon performs additional logging for debugging purposes.
29863 @defvr {Scheme Variable} ganeti-mond-service-type
29864 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
29865 functionality. It is responsible for running data collectors and publish the
29866 collected information through a HTTP interface.
29868 It takes a @code{ganeti-mond-configuration} object.
29871 @deftp {Data Type} ganeti-mond-configuration
29874 @item @code{ganeti} (default: @code{ganeti})
29875 The @code{ganeti} package to use for this service.
29877 @item @code{port} (default: @code{1815})
29878 The port on which the daemon will listen.
29880 @item @code{address} (default: @code{"0.0.0.0"})
29881 The network address that the daemon will bind to. By default it binds to all
29882 available interfaces.
29884 @item @code{debug?} (default: @code{#f})
29885 When true, the daemon performs additional logging for debugging purposes.
29890 @defvr {Scheme Variable} ganeti-metad-service-type
29891 @command{ganeti-metad} is an optional daemon that can be used to provide
29892 information about the cluster to instances or OS install scripts.
29894 It takes a @code{ganeti-metad-configuration} object.
29897 @deftp {Data Type} ganeti-metad-configuration
29900 @item @code{ganeti} (default: @code{ganeti})
29901 The @code{ganeti} package to use for this service.
29903 @item @code{port} (default: @code{80})
29904 The port on which the daemon will listen.
29906 @item @code{address} (default: @code{#f})
29907 If set, the daemon will bind to this address only. If left unset, the behavior
29908 depends on the cluster configuration.
29910 @item @code{debug?} (default: @code{#f})
29911 When true, the daemon performs additional logging for debugging purposes.
29916 @defvr {Scheme Variable} ganeti-watcher-service-type
29917 @command{ganeti-watcher} is a script designed to run periodically and ensure
29918 the health of a cluster. It will automatically restart instances that have
29919 stopped without Ganeti's consent, and repairs DRBD links in case a node has
29920 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
29921 that are not running. If the cluster parameter @code{ensure_node_health}
29922 is set, the watcher will also shutdown instances and DRBD devices if the
29923 node it is running on is declared offline by known master candidates.
29925 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
29927 The service takes a @code{ganeti-watcher-configuration} object.
29930 @deftp {Data Type} ganeti-watcher-configuration
29933 @item @code{ganeti} (default: @code{ganeti})
29934 The @code{ganeti} package to use for this service.
29936 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
29937 How often to run the script. The default is every five minutes.
29939 @item @code{rapi-ip} (default: @code{#f})
29940 This option needs to be specified only if the RAPI daemon is configured to use
29941 a particular interface or address. By default the cluster address is used.
29943 @item @code{job-age} (default: @code{(* 6 3600)})
29944 Archive cluster jobs older than this age, specified in seconds. The default
29945 is 6 hours. This keeps @command{gnt-job list} manageable.
29947 @item @code{verify-disks?} (default: @code{#t})
29948 If this is @code{#f}, the watcher will not try to repair broken DRBD links
29949 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
29952 @item @code{debug?} (default: @code{#f})
29953 When @code{#t}, the script performs additional logging for debugging purposes.
29958 @defvr {Scheme Variable} ganeti-cleaner-service-type
29959 @command{ganeti-cleaner} is a script designed to run periodically and remove
29960 old files from the cluster. This service type controls two @dfn{cron jobs}:
29961 one intended for the master node that permanently purges old cluster jobs,
29962 and one intended for every node that removes expired X509 certificates, keys,
29963 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
29964 it is safe to include even on non-master nodes as it will disable itself as
29967 It takes a @code{ganeti-cleaner-configuration} object.
29970 @deftp {Data Type} ganeti-cleaner-configuration
29973 @item @code{ganeti} (default: @code{ganeti})
29974 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
29976 @item @code{master-schedule} (default: @code{"45 1 * * *"})
29977 How often to run the master cleaning job. The default is once per day, at
29980 @item @code{node-schedule} (default: @code{"45 2 * * *"})
29981 How often to run the node cleaning job. The default is once per day, at
29987 @node Version Control Services
29988 @subsection Version Control Services
29990 The @code{(gnu services version-control)} module provides a service to
29991 allow remote access to local Git repositories. There are three options:
29992 the @code{git-daemon-service}, which provides access to repositories via
29993 the @code{git://} unsecured TCP-based protocol, extending the
29994 @code{nginx} web server to proxy some requests to
29995 @code{git-http-backend}, or providing a web interface with
29996 @code{cgit-service-type}.
29998 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
30000 Return a service that runs @command{git daemon}, a simple TCP server to
30001 expose repositories over the Git protocol for anonymous access.
30003 The optional @var{config} argument should be a
30004 @code{<git-daemon-configuration>} object, by default it allows read-only
30005 access to exported@footnote{By creating the magic file
30006 @file{git-daemon-export-ok} in the repository directory.} repositories under
30011 @deftp {Data Type} git-daemon-configuration
30012 Data type representing the configuration for @code{git-daemon-service}.
30015 @item @code{package} (default: @code{git})
30016 Package object of the Git distributed version control system.
30018 @item @code{export-all?} (default: @code{#f})
30019 Whether to allow access for all Git repositories, even if they do not
30020 have the @file{git-daemon-export-ok} file.
30022 @item @code{base-path} (default: @file{/srv/git})
30023 Whether to remap all the path requests as relative to the given path.
30024 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
30025 @samp{example.com}, then if you later try to pull
30026 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
30027 path as @file{/srv/git/hello.git}.
30029 @item @code{user-path} (default: @code{#f})
30030 Whether to allow @code{~user} notation to be used in requests. When
30031 specified with empty string, requests to
30032 @indicateurl{git://host/~alice/foo} is taken as a request to access
30033 @code{foo} repository in the home directory of user @code{alice}. If
30034 @code{(user-path "@var{path}")} is specified, the same request is taken
30035 as a request to access @file{@var{path}/foo} repository in the home
30036 directory of user @code{alice}.
30038 @item @code{listen} (default: @code{'()})
30039 Whether to listen on specific IP addresses or hostnames, defaults to
30042 @item @code{port} (default: @code{#f})
30043 Whether to listen on an alternative port, which defaults to 9418.
30045 @item @code{whitelist} (default: @code{'()})
30046 If not empty, only allow access to this list of directories.
30048 @item @code{extra-options} (default: @code{'()})
30049 Extra options will be passed to @command{git daemon}, please run
30050 @command{man git-daemon} for more information.
30055 The @code{git://} protocol lacks authentication. When you pull from a
30056 repository fetched via @code{git://}, you don't know whether the data you
30057 receive was modified or is even coming from the specified host, and your
30058 connection is subject to eavesdropping. It's better to use an authenticated
30059 and encrypted transport, such as @code{https}. Although Git allows you
30060 to serve repositories using unsophisticated file-based web servers,
30061 there is a faster protocol implemented by the @code{git-http-backend}
30062 program. This program is the back-end of a proper Git web service. It
30063 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
30064 on running the necessary @code{fcgiwrap} daemon.
30066 Guix has a separate configuration data type for serving Git repositories
30069 @deftp {Data Type} git-http-configuration
30070 Data type representing the configuration for a future
30071 @code{git-http-service-type}; can currently be used to configure Nginx
30072 through @code{git-http-nginx-location-configuration}.
30075 @item @code{package} (default: @var{git})
30076 Package object of the Git distributed version control system.
30078 @item @code{git-root} (default: @file{/srv/git})
30079 Directory containing the Git repositories to expose to the world.
30081 @item @code{export-all?} (default: @code{#f})
30082 Whether to expose access for all Git repositories in @var{git-root},
30083 even if they do not have the @file{git-daemon-export-ok} file.
30085 @item @code{uri-path} (default: @samp{/git/})
30086 Path prefix for Git access. With the default @samp{/git/} prefix, this
30087 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
30088 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
30089 with this prefix are not passed on to this Git instance.
30091 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
30092 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
30097 There is no @code{git-http-service-type}, currently; instead you can
30098 create an @code{nginx-location-configuration} from a
30099 @code{git-http-configuration} and then add that location to a web
30102 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
30103 [config=(git-http-configuration)]
30104 Compute an @code{nginx-location-configuration} that corresponds to the
30105 given Git http configuration. An example nginx service definition to
30106 serve the default @file{/srv/git} over HTTPS might be:
30109 (service nginx-service-type
30110 (nginx-configuration
30113 (nginx-server-configuration
30114 (listen '("443 ssl"))
30115 (server-name "git.my-host.org")
30117 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
30118 (ssl-certificate-key
30119 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
30122 (git-http-nginx-location-configuration
30123 (git-http-configuration (uri-path "/"))))))))))
30126 This example assumes that you are using Let's Encrypt to get your TLS
30127 certificate. @xref{Certificate Services}. The default @code{certbot}
30128 service will redirect all HTTP traffic on @code{git.my-host.org} to
30129 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
30130 system services. @xref{Web Services}.
30133 @subsubheading Cgit Service
30135 @cindex Cgit service
30136 @cindex Git, web interface
30137 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
30138 repositories written in C.
30140 The following example will configure the service with default values.
30141 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
30144 (service cgit-service-type)
30147 The @code{file-object} type designates either a file-like object
30148 (@pxref{G-Expressions, file-like objects}) or a string.
30150 @c %start of fragment
30152 Available @code{cgit-configuration} fields are:
30154 @deftypevr {@code{cgit-configuration} parameter} package package
30159 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
30160 NGINX configuration.
30164 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
30165 Specifies a command which will be invoked to format the content of about
30166 pages (both top-level and for each repository).
30168 Defaults to @samp{""}.
30172 @deftypevr {@code{cgit-configuration} parameter} string agefile
30173 Specifies a path, relative to each repository path, which can be used to
30174 specify the date and time of the youngest commit in the repository.
30176 Defaults to @samp{""}.
30180 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
30181 Specifies a command that will be invoked for authenticating repository
30184 Defaults to @samp{""}.
30188 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
30189 Flag which, when set to @samp{age}, enables date ordering in the branch
30190 ref list, and when set @samp{name} enables ordering by branch name.
30192 Defaults to @samp{"name"}.
30196 @deftypevr {@code{cgit-configuration} parameter} string cache-root
30197 Path used to store the cgit cache entries.
30199 Defaults to @samp{"/var/cache/cgit"}.
30203 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
30204 Number which specifies the time-to-live, in minutes, for the cached
30205 version of repository pages accessed with a fixed SHA1.
30207 Defaults to @samp{-1}.
30211 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
30212 Number which specifies the time-to-live, in minutes, for the cached
30213 version of repository pages accessed without a fixed SHA1.
30215 Defaults to @samp{5}.
30219 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
30220 Number which specifies the time-to-live, in minutes, for the cached
30221 version of the repository summary page.
30223 Defaults to @samp{5}.
30227 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
30228 Number which specifies the time-to-live, in minutes, for the cached
30229 version of the repository index page.
30231 Defaults to @samp{5}.
30235 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
30236 Number which specifies the time-to-live, in minutes, for the result of
30237 scanning a path for Git repositories.
30239 Defaults to @samp{15}.
30243 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
30244 Number which specifies the time-to-live, in minutes, for the cached
30245 version of the repository about page.
30247 Defaults to @samp{15}.
30251 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
30252 Number which specifies the time-to-live, in minutes, for the cached
30253 version of snapshots.
30255 Defaults to @samp{5}.
30259 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
30260 The maximum number of entries in the cgit cache. When set to @samp{0},
30261 caching is disabled.
30263 Defaults to @samp{0}.
30267 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
30268 Sort items in the repo list case sensitively.
30270 Defaults to @samp{#t}.
30274 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
30275 List of common prefixes which, when combined with a repository URL,
30276 generates valid clone URLs for the repository.
30278 Defaults to @samp{()}.
30282 @deftypevr {@code{cgit-configuration} parameter} list clone-url
30283 List of @code{clone-url} templates.
30285 Defaults to @samp{()}.
30289 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
30290 Command which will be invoked to format commit messages.
30292 Defaults to @samp{""}.
30296 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
30297 Flag which, when set to @samp{date}, enables strict date ordering in the
30298 commit log, and when set to @samp{topo} enables strict topological
30301 Defaults to @samp{"git log"}.
30305 @deftypevr {@code{cgit-configuration} parameter} file-object css
30306 URL which specifies the css document to include in all cgit pages.
30308 Defaults to @samp{"/share/cgit/cgit.css"}.
30312 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
30313 Specifies a command which will be invoked to format names and email
30314 address of committers, authors, and taggers, as represented in various
30315 places throughout the cgit interface.
30317 Defaults to @samp{""}.
30321 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
30322 Flag which, when set to @samp{#t}, will make cgit generate a HTML
30323 fragment suitable for embedding in other HTML pages.
30325 Defaults to @samp{#f}.
30329 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
30330 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
30331 commit history graph to the left of the commit messages in the
30332 repository log page.
30334 Defaults to @samp{#f}.
30338 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
30339 Flag which, when set to @samp{#t}, allows all filter settings to be
30340 overridden in repository-specific cgitrc files.
30342 Defaults to @samp{#f}.
30346 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
30347 Flag which, when set to @samp{#t}, allows users to follow a file in the
30350 Defaults to @samp{#f}.
30354 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
30355 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
30358 Defaults to @samp{#t}.
30362 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
30363 Flag which, when set to @samp{#t}, will make cgit generate extra links
30364 "summary", "commit", "tree" for each repo in the repository index.
30366 Defaults to @samp{#f}.
30370 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
30371 Flag which, when set to @samp{#t}, will make cgit display the owner of
30372 each repo in the repository index.
30374 Defaults to @samp{#t}.
30378 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
30379 Flag which, when set to @samp{#t}, will make cgit print the number of
30380 modified files for each commit on the repository log page.
30382 Defaults to @samp{#f}.
30386 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
30387 Flag which, when set to @samp{#t}, will make cgit print the number of
30388 added and removed lines for each commit on the repository log page.
30390 Defaults to @samp{#f}.
30394 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
30395 Flag which, when set to @code{#t}, will make cgit display remote
30396 branches in the summary and refs views.
30398 Defaults to @samp{#f}.
30402 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
30403 Flag which, when set to @code{1}, will make cgit use the subject of the
30404 parent commit as link text when generating links to parent commits in
30407 Defaults to @samp{#f}.
30411 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
30412 Flag which, when set to @samp{#t}, will make cgit use the subject of the
30413 parent commit as link text when generating links to parent commits in
30416 Defaults to @samp{#f}.
30420 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
30421 Flag which, when set to @samp{#t}, will make cgit generate linenumber
30422 links for plaintext blobs printed in the tree view.
30424 Defaults to @samp{#t}.
30428 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
30429 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
30430 set any repo specific settings.
30432 Defaults to @samp{#f}.
30436 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
30437 URL used as link to a shortcut icon for cgit.
30439 Defaults to @samp{"/favicon.ico"}.
30443 @deftypevr {@code{cgit-configuration} parameter} string footer
30444 The content of the file specified with this option will be included
30445 verbatim at the bottom of all pages (i.e.@: it replaces the standard
30446 "generated by..."@: message).
30448 Defaults to @samp{""}.
30452 @deftypevr {@code{cgit-configuration} parameter} string head-include
30453 The content of the file specified with this option will be included
30454 verbatim in the HTML HEAD section on all pages.
30456 Defaults to @samp{""}.
30460 @deftypevr {@code{cgit-configuration} parameter} string header
30461 The content of the file specified with this option will be included
30462 verbatim at the top of all pages.
30464 Defaults to @samp{""}.
30468 @deftypevr {@code{cgit-configuration} parameter} file-object include
30469 Name of a configfile to include before the rest of the current config-
30472 Defaults to @samp{""}.
30476 @deftypevr {@code{cgit-configuration} parameter} string index-header
30477 The content of the file specified with this option will be included
30478 verbatim above the repository index.
30480 Defaults to @samp{""}.
30484 @deftypevr {@code{cgit-configuration} parameter} string index-info
30485 The content of the file specified with this option will be included
30486 verbatim below the heading on the repository index page.
30488 Defaults to @samp{""}.
30492 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
30493 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
30494 in the servers timezone.
30496 Defaults to @samp{#f}.
30500 @deftypevr {@code{cgit-configuration} parameter} file-object logo
30501 URL which specifies the source of an image which will be used as a logo
30504 Defaults to @samp{"/share/cgit/cgit.png"}.
30508 @deftypevr {@code{cgit-configuration} parameter} string logo-link
30509 URL loaded when clicking on the cgit logo image.
30511 Defaults to @samp{""}.
30515 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
30516 Command which will be invoked to format the Owner column of the main
30519 Defaults to @samp{""}.
30523 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
30524 Number of items to display in atom feeds view.
30526 Defaults to @samp{10}.
30530 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
30531 Number of entries to list per page in "log" view.
30533 Defaults to @samp{50}.
30537 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
30538 Number of commit message characters to display in "log" view.
30540 Defaults to @samp{80}.
30544 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
30545 Specifies the number of entries to list per page on the repository index
30548 Defaults to @samp{50}.
30552 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
30553 Specifies the maximum number of repo description characters to display
30554 on the repository index page.
30556 Defaults to @samp{80}.
30560 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
30561 Specifies the maximum size of a blob to display HTML for in KBytes.
30563 Defaults to @samp{0}.
30567 @deftypevr {@code{cgit-configuration} parameter} string max-stats
30568 Maximum statistics period. Valid values are @samp{week},@samp{month},
30569 @samp{quarter} and @samp{year}.
30571 Defaults to @samp{""}.
30575 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
30576 Mimetype for the specified filename extension.
30578 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
30579 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
30580 "image/png") (svg "image/svg+xml"))}.
30584 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
30585 Specifies the file to use for automatic mimetype lookup.
30587 Defaults to @samp{""}.
30591 @deftypevr {@code{cgit-configuration} parameter} string module-link
30592 Text which will be used as the formatstring for a hyperlink when a
30593 submodule is printed in a directory listing.
30595 Defaults to @samp{""}.
30599 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
30600 If set to the value @samp{#t} caching will be disabled.
30602 Defaults to @samp{#f}.
30606 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
30607 If set to @samp{#t} showing full author email addresses will be
30610 Defaults to @samp{#f}.
30614 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
30615 Flag which, when set to @samp{#t}, will make cgit omit the standard
30616 header on all pages.
30618 Defaults to @samp{#f}.
30622 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
30623 A list of subdirectories inside of @code{repository-directory}, relative
30624 to it, that should loaded as Git repositories. An empty list means that
30625 all subdirectories will be loaded.
30627 Defaults to @samp{()}.
30631 @deftypevr {@code{cgit-configuration} parameter} file-object readme
30632 Text which will be used as default value for @code{cgit-repo-readme}.
30634 Defaults to @samp{""}.
30638 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
30639 If set to @code{#t} and @code{repository-directory} is enabled, if any
30640 repositories are found with a suffix of @code{.git}, this suffix will be
30641 removed for the URL and name.
30643 Defaults to @samp{#f}.
30647 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
30648 Maximum number of files to consider when detecting renames.
30650 Defaults to @samp{-1}.
30654 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
30655 The way in which repositories in each section are sorted.
30657 Defaults to @samp{""}.
30661 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
30662 Text used as content for the @code{robots} meta-tag.
30664 Defaults to @samp{("noindex" "nofollow")}.
30668 @deftypevr {@code{cgit-configuration} parameter} string root-desc
30669 Text printed below the heading on the repository index page.
30671 Defaults to @samp{"a fast webinterface for the git dscm"}.
30675 @deftypevr {@code{cgit-configuration} parameter} string root-readme
30676 The content of the file specified with this option will be included
30677 verbatim below the ``about'' link on the repository index page.
30679 Defaults to @samp{""}.
30683 @deftypevr {@code{cgit-configuration} parameter} string root-title
30684 Text printed as heading on the repository index page.
30686 Defaults to @samp{""}.
30690 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
30691 If set to @samp{#t} and repository-directory is enabled,
30692 repository-directory will recurse into directories whose name starts
30693 with a period. Otherwise, repository-directory will stay away from such
30694 directories, considered as ``hidden''. Note that this does not apply to
30695 the @file{.git} directory in non-bare repos.
30697 Defaults to @samp{#f}.
30701 @deftypevr {@code{cgit-configuration} parameter} list snapshots
30702 Text which specifies the default set of snapshot formats that cgit
30703 generates links for.
30705 Defaults to @samp{()}.
30709 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
30710 Name of the directory to scan for repositories (represents
30713 Defaults to @samp{"/srv/git"}.
30717 @deftypevr {@code{cgit-configuration} parameter} string section
30718 The name of the current repository section - all repositories defined
30719 after this option will inherit the current section name.
30721 Defaults to @samp{""}.
30725 @deftypevr {@code{cgit-configuration} parameter} string section-sort
30726 Flag which, when set to @samp{1}, will sort the sections on the
30727 repository listing by name.
30729 Defaults to @samp{""}.
30733 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
30734 A number which, if defined prior to repository-directory, specifies how
30735 many path elements from each repo path to use as a default section name.
30737 Defaults to @samp{0}.
30741 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
30742 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
30745 Defaults to @samp{#f}.
30749 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
30750 Specifies a command which will be invoked to format plaintext blobs in
30753 Defaults to @samp{""}.
30757 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
30758 Specifies the number of branches to display in the repository ``summary''
30761 Defaults to @samp{10}.
30765 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
30766 Specifies the number of log entries to display in the repository
30769 Defaults to @samp{10}.
30773 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
30774 Specifies the number of tags to display in the repository ``summary''
30777 Defaults to @samp{10}.
30781 @deftypevr {@code{cgit-configuration} parameter} string strict-export
30782 Filename which, if specified, needs to be present within the repository
30783 for cgit to allow access to that repository.
30785 Defaults to @samp{""}.
30789 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
30790 URL which, if specified, will be used as root for all cgit links.
30792 Defaults to @samp{"/"}.
30796 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
30797 A list of @dfn{cgit-repo} records to use with config.
30799 Defaults to @samp{()}.
30801 Available @code{repository-cgit-configuration} fields are:
30803 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
30804 A mask of snapshot formats for this repo that cgit generates links for,
30805 restricted by the global @code{snapshots} setting.
30807 Defaults to @samp{()}.
30811 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
30812 Override the default @code{source-filter}.
30814 Defaults to @samp{""}.
30818 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
30819 The relative URL used to access the repository.
30821 Defaults to @samp{""}.
30825 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
30826 Override the default @code{about-filter}.
30828 Defaults to @samp{""}.
30832 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
30833 Flag which, when set to @samp{age}, enables date ordering in the branch
30834 ref list, and when set to @samp{name} enables ordering by branch name.
30836 Defaults to @samp{""}.
30840 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
30841 A list of URLs which can be used to clone repo.
30843 Defaults to @samp{()}.
30847 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
30848 Override the default @code{commit-filter}.
30850 Defaults to @samp{""}.
30854 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
30855 Flag which, when set to @samp{date}, enables strict date ordering in the
30856 commit log, and when set to @samp{topo} enables strict topological
30859 Defaults to @samp{""}.
30863 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
30864 The name of the default branch for this repository. If no such branch
30865 exists in the repository, the first branch name (when sorted) is used as
30866 default instead. By default branch pointed to by HEAD, or ``master'' if
30867 there is no suitable HEAD.
30869 Defaults to @samp{""}.
30873 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
30874 The value to show as repository description.
30876 Defaults to @samp{""}.
30880 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
30881 The value to show as repository homepage.
30883 Defaults to @samp{""}.
30887 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
30888 Override the default @code{email-filter}.
30890 Defaults to @samp{""}.
30894 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
30895 A flag which can be used to disable the global setting
30896 @code{enable-commit-graph?}.
30898 Defaults to @samp{disabled}.
30902 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
30903 A flag which can be used to disable the global setting
30904 @code{enable-log-filecount?}.
30906 Defaults to @samp{disabled}.
30910 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
30911 A flag which can be used to disable the global setting
30912 @code{enable-log-linecount?}.
30914 Defaults to @samp{disabled}.
30918 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
30919 Flag which, when set to @code{#t}, will make cgit display remote
30920 branches in the summary and refs views.
30922 Defaults to @samp{disabled}.
30926 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
30927 A flag which can be used to override the global setting
30928 @code{enable-subject-links?}.
30930 Defaults to @samp{disabled}.
30934 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
30935 A flag which can be used to override the global setting
30936 @code{enable-html-serving?}.
30938 Defaults to @samp{disabled}.
30942 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
30943 Flag which, when set to @code{#t}, hides the repository from the
30946 Defaults to @samp{#f}.
30950 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
30951 Flag which, when set to @samp{#t}, ignores the repository.
30953 Defaults to @samp{#f}.
30957 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
30958 URL which specifies the source of an image which will be used as a logo
30959 on this repo’s pages.
30961 Defaults to @samp{""}.
30965 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
30966 URL loaded when clicking on the cgit logo image.
30968 Defaults to @samp{""}.
30972 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
30973 Override the default @code{owner-filter}.
30975 Defaults to @samp{""}.
30979 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
30980 Text which will be used as the formatstring for a hyperlink when a
30981 submodule is printed in a directory listing. The arguments for the
30982 formatstring are the path and SHA1 of the submodule commit.
30984 Defaults to @samp{""}.
30988 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
30989 Text which will be used as the formatstring for a hyperlink when a
30990 submodule with the specified subdirectory path is printed in a directory
30993 Defaults to @samp{()}.
30997 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
30998 Override the default maximum statistics period.
31000 Defaults to @samp{""}.
31004 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
31005 The value to show as repository name.
31007 Defaults to @samp{""}.
31011 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
31012 A value used to identify the owner of the repository.
31014 Defaults to @samp{""}.
31018 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
31019 An absolute path to the repository directory.
31021 Defaults to @samp{""}.
31025 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
31026 A path (relative to repo) which specifies a file to include verbatim as
31027 the ``About'' page for this repo.
31029 Defaults to @samp{""}.
31033 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
31034 The name of the current repository section - all repositories defined
31035 after this option will inherit the current section name.
31037 Defaults to @samp{""}.
31041 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
31042 Extra options will be appended to cgitrc file.
31044 Defaults to @samp{()}.
31050 @deftypevr {@code{cgit-configuration} parameter} list extra-options
31051 Extra options will be appended to cgitrc file.
31053 Defaults to @samp{()}.
31058 @c %end of fragment
31060 However, it could be that you just want to get a @code{cgitrc} up and
31061 running. In that case, you can pass an @code{opaque-cgit-configuration}
31062 as a record to @code{cgit-service-type}. As its name indicates, an
31063 opaque configuration does not have easy reflective capabilities.
31065 Available @code{opaque-cgit-configuration} fields are:
31067 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
31071 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
31072 The contents of the @code{cgitrc}, as a string.
31075 For example, if your @code{cgitrc} is just the empty string, you
31076 could instantiate a cgit service like this:
31079 (service cgit-service-type
31080 (opaque-cgit-configuration
31084 @subsubheading Gitolite Service
31086 @cindex Gitolite service
31087 @cindex Git, hosting
31088 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
31089 repositories on a central server.
31091 Gitolite can handle multiple repositories and users, and supports flexible
31092 configuration of the permissions for the users on the repositories.
31094 The following example will configure Gitolite using the default @code{git}
31095 user, and the provided SSH public key.
31098 (service gitolite-service-type
31099 (gitolite-configuration
31100 (admin-pubkey (plain-file
31102 "ssh-rsa AAAA... guix@@example.com"))))
31105 Gitolite is configured through a special admin repository which you can clone,
31106 for example, if you setup Gitolite on @code{example.com}, you would run the
31107 following command to clone the admin repository.
31110 git clone git@@example.com:gitolite-admin
31113 When the Gitolite service is activated, the provided @code{admin-pubkey} will
31114 be inserted in to the @file{keydir} directory in the gitolite-admin
31115 repository. If this results in a change in the repository, it will be
31116 committed using the message ``gitolite setup by GNU Guix''.
31118 @deftp {Data Type} gitolite-configuration
31119 Data type representing the configuration for @code{gitolite-service-type}.
31122 @item @code{package} (default: @var{gitolite})
31123 Gitolite package to use.
31125 @item @code{user} (default: @var{git})
31126 User to use for Gitolite. This will be user that you use when accessing
31129 @item @code{group} (default: @var{git})
31130 Group to use for Gitolite.
31132 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
31133 Directory in which to store the Gitolite configuration and repositories.
31135 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
31136 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
31137 representing the configuration for Gitolite.
31139 @item @code{admin-pubkey} (default: @var{#f})
31140 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
31141 setup Gitolite. This will be inserted in to the @file{keydir} directory
31142 within the gitolite-admin repository.
31144 To specify the SSH key as a string, use the @code{plain-file} function.
31147 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
31153 @deftp {Data Type} gitolite-rc-file
31154 Data type representing the Gitolite RC file.
31157 @item @code{umask} (default: @code{#o0077})
31158 This controls the permissions Gitolite sets on the repositories and their
31161 A value like @code{#o0027} will give read access to the group used by Gitolite
31162 (by default: @code{git}). This is necessary when using Gitolite with software
31163 like cgit or gitweb.
31165 @item @code{git-config-keys} (default: @code{""})
31166 Gitolite allows you to set git config values using the @samp{config}
31167 keyword. This setting allows control over the config keys to accept.
31169 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
31170 Set the role names allowed to be used by users running the perms command.
31172 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
31173 This setting controls the commands and features to enable within Gitolite.
31179 @node Game Services
31180 @subsection Game Services
31182 @subsubheading The Battle for Wesnoth Service
31184 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
31185 based tactical strategy game, with several single player campaigns, and
31186 multiplayer games (both networked and local).
31188 @defvar {Scheme Variable} wesnothd-service-type
31189 Service type for the wesnothd service. Its value must be a
31190 @code{wesnothd-configuration} object. To run wesnothd in the default
31191 configuration, instantiate it as:
31194 (service wesnothd-service-type)
31198 @deftp {Data Type} wesnothd-configuration
31199 Data type representing the configuration of @command{wesnothd}.
31202 @item @code{package} (default: @code{wesnoth-server})
31203 The wesnoth server package to use.
31205 @item @code{port} (default: @code{15000})
31206 The port to bind the server to.
31211 @node PAM Mount Service
31212 @subsection PAM Mount Service
31215 The @code{(gnu services pam-mount)} module provides a service allowing
31216 users to mount volumes when they log in. It should be able to mount any
31217 volume format supported by the system.
31219 @defvar {Scheme Variable} pam-mount-service-type
31220 Service type for PAM Mount support.
31223 @deftp {Data Type} pam-mount-configuration
31224 Data type representing the configuration of PAM Mount.
31226 It takes the following parameters:
31230 The configuration rules that will be used to generate
31231 @file{/etc/security/pam_mount.conf.xml}.
31233 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
31234 Guile Reference Manual}), and the default ones don't mount anything for
31238 `((debug (@@ (enable "0")))
31239 (mntoptions (@@ (allow ,(string-join
31240 '("nosuid" "nodev" "loop"
31241 "encryption" "fsck" "nonempty"
31242 "allow_root" "allow_other")
31244 (mntoptions (@@ (require "nosuid,nodev")))
31245 (logout (@@ (wait "0")
31249 (mkmountpoint (@@ (enable "1")
31253 Some @code{volume} elements must be added to automatically mount volumes
31254 at login. Here's an example allowing the user @code{alice} to mount her
31255 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
31256 the partition where he stores his data:
31259 (define pam-mount-rules
31260 `((debug (@@ (enable "0")))
31261 (volume (@@ (user "alice")
31264 (mountpoint "/home/alice")))
31265 (volume (@@ (user "bob")
31268 (mountpoint "/home/bob/data")
31269 (options "defaults,autodefrag,compress")))
31270 (mntoptions (@@ (allow ,(string-join
31271 '("nosuid" "nodev" "loop"
31272 "encryption" "fsck" "nonempty"
31273 "allow_root" "allow_other")
31275 (mntoptions (@@ (require "nosuid,nodev")))
31276 (logout (@@ (wait "0")
31280 (mkmountpoint (@@ (enable "1")
31281 (remove "true")))))
31283 (service pam-mount-service-type
31284 (pam-mount-configuration
31285 (rules pam-mount-rules)))
31288 The complete list of possible options can be found in the man page for
31289 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
31294 @node Guix Services
31295 @subsection Guix Services
31297 @subsubheading Guix Build Coordinator
31298 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
31299 Coordinator} aids in distributing derivation builds among machines
31300 running an @dfn{agent}. The build daemon is still used to build the
31301 derivations, but the Guix Build Coordinator manages allocating builds
31302 and working with the results.
31305 This service is considered experimental. Configuration options may be
31306 changed in a backwards-incompatible manner, and not all features have
31307 been thorougly tested.
31310 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
31311 more connected @dfn{agent} processes. The coordinator process handles
31312 clients submitting builds, and allocating builds to agents. The agent
31313 processes talk to a build daemon to actually perform the builds, then
31314 send the results back to the coordinator.
31316 There is a script to run the coordinator component of the Guix Build
31317 Coordinator, but the Guix service uses a custom Guile script instead, to
31318 provide better integration with G-expressions used in the configuration.
31320 @defvar {Scheme Variable} guix-build-coordinator-service-type
31321 Service type for the Guix Build Coordinator. Its value must be a
31322 @code{guix-build-coordinator-configuration} object.
31325 @deftp {Data Type} guix-build-coordinator-configuration
31326 Data type representing the configuration of the Guix Build Coordinator.
31329 @item @code{package} (default: @code{guix-build-coordinator})
31330 The Guix Build Coordinator package to use.
31332 @item @code{user} (default: @code{"guix-build-coordinator"})
31333 The system user to run the service as.
31335 @item @code{group} (default: @code{"guix-build-coordinator"})
31336 The system group to run the service as.
31338 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
31339 The URI to use for the database.
31341 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
31342 The URI describing how to listen to requests from agent processes.
31344 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
31345 The URI describing how to listen to requests from clients. The client
31346 API allows submitting builds and currently isn't authenticated, so take
31347 care when configuring this value.
31349 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
31350 A G-expression for the allocation strategy to be used. This is a
31351 procedure that takes the datastore as an argument and populates the
31352 allocation plan in the database.
31354 @item @code{hooks} (default: @var{'()})
31355 An association list of hooks. These provide a way to execute arbitrary
31356 code upon certain events, like a build result being processed.
31358 @item @code{guile} (default: @code{guile-3.0-latest})
31359 The Guile package with which to run the Guix Build Coordinator.
31364 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
31365 Service type for a Guix Build Coordinator agent. Its value must be a
31366 @code{guix-build-coordinator-agent-configuration} object.
31369 @deftp {Data Type} guix-build-coordinator-agent-configuration
31370 Data type representing the configuration a Guix Build Coordinator agent.
31373 @item @code{package} (default: @code{guix-build-coordinator})
31374 The Guix Build Coordinator package to use.
31376 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
31377 The system user to run the service as.
31379 @item @code{coordinator} (default: @code{"http://localhost:8745"})
31380 The URI to use when connecting to the coordinator.
31382 @item @code{authentication}
31383 Record describing how this agent should authenticate with the
31384 coordinator. Possible record types are described below.
31386 @item @code{systems} (default: @code{#f})
31387 The systems for which this agent should fetch builds. The agent process
31388 will use the current system it's running on as the default.
31390 @item @code{max-parallel-builds} (default: @code{1})
31391 The number of builds to perform in parallel.
31393 @item @code{max-1min-load-average} (default: @code{#f})
31394 Load average value to look at when considering starting new builds, if
31395 the 1 minute load average exceeds this value, the agent will wait before
31396 starting new builds.
31398 This will be unspecified if the value is @code{#f}, and the agent will
31399 use the number of cores reported by the system as the max 1 minute load
31402 @item @code{derivation-substitute-urls} (default: @code{#f})
31403 URLs from which to attempt to fetch substitutes for derivations, if the
31404 derivations aren't already available.
31406 @item @code{non-derivation-substitute-urls} (default: @code{#f})
31407 URLs from which to attempt to fetch substitutes for build inputs, if the
31408 input store items aren't already available.
31413 @deftp {Data Type} guix-build-coordinator-agent-password-auth
31414 Data type representing an agent authenticating with a coordinator via a
31419 The UUID of the agent. This should be generated by the coordinator
31420 process, stored in the coordinator database, and used by the intended
31423 @item @code{password}
31424 The password to use when connecting to the coordinator.
31429 @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
31430 Data type representing an agent authenticating with a coordinator via a
31431 UUID and password read from a file.
31435 The UUID of the agent. This should be generated by the coordinator
31436 process, stored in the coordinator database, and used by the intended
31439 @item @code{password-file}
31440 A file containing the password to use when connecting to the
31446 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
31447 Data type representing an agent authenticating with a coordinator via a
31448 dynamic auth token and agent name.
31451 @item @code{agent-name}
31452 Name of an agent, this is used to match up to an existing entry in the
31453 database if there is one. When no existing entry is found, a new entry
31454 is automatically added.
31457 Dynamic auth token, this is created and stored in the coordinator
31458 database, and is used by the agent to authenticate.
31463 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
31464 Data type representing an agent authenticating with a coordinator via a
31465 dynamic auth token read from a file and agent name.
31468 @item @code{agent-name}
31469 Name of an agent, this is used to match up to an existing entry in the
31470 database if there is one. When no existing entry is found, a new entry
31471 is automatically added.
31473 @item @code{token-file}
31474 File containing the dynamic auth token, this is created and stored in
31475 the coordinator database, and is used by the agent to authenticate.
31480 The Guix Build Coordinator package contains a script to query an
31481 instance of the Guix Data Service for derivations to build, and then
31482 submit builds for those derivations to the coordinator. The service
31483 type below assists in running this script. This is an additional tool
31484 that may be useful when building derivations contained within an
31485 instance of the Guix Data Service.
31487 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
31488 Service type for the
31489 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
31490 value must be a @code{guix-build-coordinator-queue-builds-configuration}
31494 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
31495 Data type representing the options to the queue builds from guix data
31499 @item @code{package} (default: @code{guix-build-coordinator})
31500 The Guix Build Coordinator package to use.
31502 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
31503 The system user to run the service as.
31505 @item @code{coordinator} (default: @code{"http://localhost:8746"})
31506 The URI to use when connecting to the coordinator.
31508 @item @code{systems} (default: @code{#f})
31509 The systems for which to fetch derivations to build.
31511 @item @code{systems-and-targets} (default: @code{#f})
31512 An association list of system and target pairs for which to fetch
31513 derivations to build.
31515 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
31516 The Guix Data Service instance from which to query to find out about
31517 derivations to build.
31519 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
31520 A file to record which commits have been processed, to avoid needlessly
31521 processing them again if the service is restarted.
31526 @subsubheading Guix Data Service
31527 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
31528 and provides data about GNU Guix. This includes information about
31529 packages, derivations and lint warnings.
31531 The data is stored in a PostgreSQL database, and available through a web
31534 @defvar {Scheme Variable} guix-data-service-type
31535 Service type for the Guix Data Service. Its value must be a
31536 @code{guix-data-service-configuration} object. The service optionally
31537 extends the getmail service, as the guix-commits mailing list is used to
31538 find out about changes in the Guix git repository.
31541 @deftp {Data Type} guix-data-service-configuration
31542 Data type representing the configuration of the Guix Data Service.
31545 @item @code{package} (default: @code{guix-data-service})
31546 The Guix Data Service package to use.
31548 @item @code{user} (default: @code{"guix-data-service"})
31549 The system user to run the service as.
31551 @item @code{group} (default: @code{"guix-data-service"})
31552 The system group to run the service as.
31554 @item @code{port} (default: @code{8765})
31555 The port to bind the web service to.
31557 @item @code{host} (default: @code{"127.0.0.1"})
31558 The host to bind the web service to.
31560 @item @code{getmail-idle-mailboxes} (default: @code{#f})
31561 If set, this is the list of mailboxes that the getmail service will be
31562 configured to listen to.
31564 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
31565 If set, this is the @code{getmail-retriever-configuration} object with
31566 which to configure getmail to fetch mail from the guix-commits mailing
31569 @item @code{extra-options} (default: @var{'()})
31570 Extra command line options for @code{guix-data-service}.
31572 @item @code{extra-process-jobs-options} (default: @var{'()})
31573 Extra command line options for @code{guix-data-service-process-jobs}.
31578 @node Linux Services
31579 @subsection Linux Services
31582 @cindex out of memory killer
31584 @cindex early out of memory daemon
31585 @subsubheading Early OOM Service
31587 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
31588 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
31589 space and provides a more responsive and configurable alternative to the
31590 in-kernel OOM killer. It is useful to prevent the system from becoming
31591 unresponsive when it runs out of memory.
31593 @deffn {Scheme Variable} earlyoom-service-type
31594 The service type for running @command{earlyoom}, the Early OOM daemon.
31595 Its value must be a @code{earlyoom-configuration} object, described
31596 below. The service can be instantiated in its default configuration
31600 (service earlyoom-service-type)
31604 @deftp {Data Type} earlyoom-configuration
31605 This is the configuration record for the @code{earlyoom-service-type}.
31608 @item @code{earlyoom} (default: @var{earlyoom})
31609 The Earlyoom package to use.
31611 @item @code{minimum-available-memory} (default: @code{10})
31612 The threshold for the minimum @emph{available} memory, in percentages.
31614 @item @code{minimum-free-swap} (default: @code{10})
31615 The threshold for the minimum free swap memory, in percentages.
31617 @item @code{prefer-regexp} (default: @code{#f})
31618 A regular expression (as a string) to match the names of the processes
31619 that should be preferably killed.
31621 @item @code{avoid-regexp} (default: @code{#f})
31622 A regular expression (as a string) to match the names of the processes
31623 that should @emph{not} be killed.
31625 @item @code{memory-report-interval} (default: @code{0})
31626 The interval in seconds at which a memory report is printed. It is
31627 disabled by default.
31629 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
31630 A boolean indicating whether the positive adjustments set in
31631 @file{/proc/*/oom_score_adj} should be ignored.
31633 @item @code{show-debug-messages?} (default: @code{#f})
31634 A boolean indicating whether debug messages should be printed. The logs
31635 are saved at @file{/var/log/earlyoom.log}.
31637 @item @code{send-notification-command} (default: @code{#f})
31638 This can be used to provide a custom command used for sending
31644 @cindex kernel module loader
31645 @subsubheading Kernel Module Loader Service
31647 The kernel module loader service allows one to load loadable kernel
31648 modules at boot. This is especially useful for modules that don't
31649 autoload and need to be manually loaded, as is the case with
31652 @deffn {Scheme Variable} kernel-module-loader-service-type
31653 The service type for loading loadable kernel modules at boot with
31654 @command{modprobe}. Its value must be a list of strings representing
31655 module names. For example loading the drivers provided by
31656 @code{ddcci-driver-linux}, in debugging mode by passing some module
31657 parameters, can be done as follow:
31660 (use-modules (gnu) (gnu services))
31661 (use-package-modules linux)
31662 (use-service-modules linux)
31664 (define ddcci-config
31665 (plain-file "ddcci.conf"
31666 "options ddcci dyndbg delay=120"))
31670 (services (cons* (service kernel-module-loader-service-type
31671 '("ddcci" "ddcci_backlight"))
31672 (simple-service 'ddcci-config etc-service-type
31673 (list `("modprobe.d/ddcci.conf"
31676 (kernel-loadable-modules (list ddcci-driver-linux)))
31681 @cindex Platform Reliability, Availability and Serviceability daemon
31682 @subsubheading Rasdaemon Service
31684 The Rasdaemon service provides a daemon which monitors platform
31685 @acronym{RAS, Reliability@comma{} Availability@comma{} and Serviceability} reports from
31686 Linux kernel trace events, logging them to syslogd.
31688 Reliability, Availability and Serviceability is a concept used on servers meant
31689 to measure their robustness.
31691 @strong{Relability} is the probability that a system will produce correct
31695 @item Generally measured as Mean Time Between Failures (MTBF), and
31696 @item Enhanced by features that help to avoid, detect and repair hardware
31700 @strong{Availability} is the probability that a system is operational at a
31704 @item Generally measured as a percentage of downtime per a period of time, and
31705 @item Often uses mechanisms to detect and correct hardware faults in runtime.
31708 @strong{Serviceability} is the simplicity and speed with which a system can be
31709 repaired or maintained:
31712 @item Generally measured on Mean Time Between Repair (MTBR).
31716 Among the monitoring measures, the most usual ones include:
31719 @item CPU – detect errors at instruction execution and at L1/L2/L3 caches;
31720 @item Memory – add error correction logic (ECC) to detect and correct errors;
31721 @item I/O – add CRC checksums for transferred data;
31722 @item Storage – RAID, journal file systems, checksums, Self-Monitoring,
31723 Analysis and Reporting Technology (SMART).
31726 By monitoring the number of occurrences of error detections, it is possible to
31727 identify if the probability of hardware errors is increasing, and, on such
31728 case, do a preventive maintenance to replace a degraded component while those
31729 errors are correctable.
31731 For detailed information about the types of error events gathered and how to
31732 make sense of them, see the kernel administrator's guide at
31733 @url{https://www.kernel.org/doc/html/latest/admin-guide/ras.html}.
31735 @defvr {Scheme Variable} rasdaemon-service-type
31736 Service type for the @command{rasdaemon} service. It accepts a
31737 @code{rasdaemon-configuration} object. Instantiating like
31740 (service rasdaemon-service-type)
31743 will load with a default configuration, which monitors all events and logs to
31747 @deftp {Data Type} rasdaemon-configuration
31748 The data type representing the configuration of @command{rasdaemon}.
31751 @item @code{record?} (default: @code{#f})
31753 A boolean indicating whether to record the events in an SQLite database. This
31754 provides a more structured access to the information contained in the log file.
31755 The database location is hard-coded to @file{/var/lib/rasdaemon/ras-mc_event.db}.
31761 @cindex compressed swap
31762 @cindex Compressed RAM-based block devices
31763 @subsubheading Zram Device Service
31765 The Zram device service provides a compressed swap device in system
31766 memory. The Linux Kernel documentation has more information about
31767 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
31770 @deffn {Scheme Variable} zram-device-service-type
31771 This service creates the zram block device, formats it as swap and
31772 enables it as a swap device. The service's value is a
31773 @code{zram-device-configuration} record.
31775 @deftp {Data Type} zram-device-configuration
31776 This is the data type representing the configuration for the zram-device
31780 @item @code{size} (default @code{"1G"})
31781 This is the amount of space you wish to provide for the zram device. It
31782 accepts a string and can be a number of bytes or use a suffix, eg.:
31783 @code{"512M"} or @code{1024000}.
31784 @item @code{compression-algorithm} (default @code{'lzo})
31785 This is the compression algorithm you wish to use. It is difficult to
31786 list all the possible compression options, but common ones supported by
31787 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
31788 @item @code{memory-limit} (default @code{0})
31789 This is the maximum amount of memory which the zram device can use.
31790 Setting it to '0' disables the limit. While it is generally expected
31791 that compression will be 2:1, it is possible that uncompressable data
31792 can be written to swap and this is a method to limit how much memory can
31793 be used. It accepts a string and can be a number of bytes or use a
31794 suffix, eg.: @code{"2G"}.
31795 @item @code{priority} (default @code{-1})
31796 This is the priority of the swap device created from the zram device.
31797 @code{swapon} accepts values between -1 and 32767, with higher values
31798 indicating higher priority. Higher priority swap will generally be used
31805 @node Hurd Services
31806 @subsection Hurd Services
31808 @defvr {Scheme Variable} hurd-console-service-type
31809 This service starts the fancy @code{VGA} console client on the Hurd.
31811 The service's value is a @code{hurd-console-configuration} record.
31814 @deftp {Data Type} hurd-console-configuration
31815 This is the data type representing the configuration for the
31816 hurd-console-service.
31819 @item @code{hurd} (default: @var{hurd})
31820 The Hurd package to use.
31824 @defvr {Scheme Variable} hurd-getty-service-type
31825 This service starts a tty using the Hurd @code{getty} program.
31827 The service's value is a @code{hurd-getty-configuration} record.
31830 @deftp {Data Type} hurd-getty-configuration
31831 This is the data type representing the configuration for the
31832 hurd-getty-service.
31835 @item @code{hurd} (default: @var{hurd})
31836 The Hurd package to use.
31839 The name of the console this Getty runs on---e.g., @code{"tty1"}.
31841 @item @code{baud-rate} (default: @code{38400})
31842 An integer specifying the baud rate of the tty.
31847 @node Miscellaneous Services
31848 @subsection Miscellaneous Services
31850 @cindex fingerprint
31851 @subsubheading Fingerprint Service
31853 The @code{(gnu services authentication)} module provides a DBus service to
31854 read and identify fingerprints via a fingerprint sensor.
31856 @defvr {Scheme Variable} fprintd-service-type
31857 The service type for @command{fprintd}, which provides the fingerprint
31858 reading capability.
31861 (service fprintd-service-type)
31866 @subsubheading System Control Service
31868 The @code{(gnu services sysctl)} provides a service to configure kernel
31869 parameters at boot.
31871 @defvr {Scheme Variable} sysctl-service-type
31872 The service type for @command{sysctl}, which modifies kernel parameters
31873 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
31877 (service sysctl-service-type
31878 (sysctl-configuration
31879 (settings '(("net.ipv4.ip_forward" . "1")))))
31882 Since @code{sysctl-service-type} is used in the default lists of
31883 services, @code{%base-services} and @code{%desktop-services}, you can
31884 use @code{modify-services} to change its configuration and add the
31885 kernel parameters that you want (@pxref{Service Reference,
31886 @code{modify-services}}).
31889 (modify-services %base-services
31890 (sysctl-service-type config =>
31891 (sysctl-configuration
31892 (settings (append '(("net.ipv4.ip_forward" . "1"))
31893 %default-sysctl-settings)))))
31898 @deftp {Data Type} sysctl-configuration
31899 The data type representing the configuration of @command{sysctl}.
31902 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
31903 The @command{sysctl} executable to use.
31905 @item @code{settings} (default: @code{%default-sysctl-settings})
31906 An association list specifies kernel parameters and their values.
31910 @defvr {Scheme Variable} %default-sysctl-settings
31911 An association list specifying the default @command{sysctl} parameters
31916 @subsubheading PC/SC Smart Card Daemon Service
31918 The @code{(gnu services security-token)} module provides the following service
31919 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
31920 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
31921 manager that coordinates communications with smart card readers, smart cards
31922 and cryptographic tokens that are connected to the system.
31924 @defvr {Scheme Variable} pcscd-service-type
31925 Service type for the @command{pcscd} service. Its value must be a
31926 @code{pcscd-configuration} object. To run pcscd in the default
31927 configuration, instantiate it as:
31930 (service pcscd-service-type)
31934 @deftp {Data Type} pcscd-configuration
31935 The data type representing the configuration of @command{pcscd}.
31938 @item @code{pcsc-lite} (default: @code{pcsc-lite})
31939 The pcsc-lite package that provides pcscd.
31940 @item @code{usb-drivers} (default: @code{(list ccid)})
31941 List of packages that provide USB drivers to pcscd. Drivers are expected to be
31942 under @file{pcsc/drivers} in the store directory of the package.
31947 @subsubheading Lirc Service
31949 The @code{(gnu services lirc)} module provides the following service.
31951 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
31952 [#:device #f] [#:driver #f] [#:config-file #f] @
31953 [#:extra-options '()]
31954 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
31955 decodes infrared signals from remote controls.
31957 Optionally, @var{device}, @var{driver} and @var{config-file}
31958 (configuration file name) may be specified. See @command{lircd} manual
31961 Finally, @var{extra-options} is a list of additional command-line options
31962 passed to @command{lircd}.
31966 @subsubheading Spice Service
31968 The @code{(gnu services spice)} module provides the following service.
31970 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
31971 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
31972 that enables sharing the clipboard with a vm and setting the guest display
31973 resolution when the graphical console window resizes.
31976 @cindex inputattach
31977 @subsubheading inputattach Service
31979 @cindex tablet input, for Xorg
31980 @cindex touchscreen input, for Xorg
31981 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
31982 use input devices such as Wacom tablets, touchscreens, or joysticks with the
31983 Xorg display server.
31985 @deffn {Scheme Variable} inputattach-service-type
31986 Type of a service that runs @command{inputattach} on a device and
31987 dispatches events from it.
31990 @deftp {Data Type} inputattach-configuration
31992 @item @code{device-type} (default: @code{"wacom"})
31993 The type of device to connect to. Run @command{inputattach --help}, from the
31994 @code{inputattach} package, to see the list of supported device types.
31996 @item @code{device} (default: @code{"/dev/ttyS0"})
31997 The device file to connect to the device.
31999 @item @code{baud-rate} (default: @code{#f})
32000 Baud rate to use for the serial connection.
32001 Should be a number or @code{#f}.
32003 @item @code{log-file} (default: @code{#f})
32004 If true, this must be the name of a file to log messages to.
32008 @subsubheading Dictionary Service
32010 The @code{(gnu services dict)} module provides the following service:
32012 @defvr {Scheme Variable} dicod-service-type
32013 This is the type of the service that runs the @command{dicod} daemon, an
32014 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
32017 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
32018 Return a service that runs the @command{dicod} daemon, an implementation
32019 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
32021 The optional @var{config} argument specifies the configuration for
32022 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
32023 default it serves the GNU Collaborative International Dictionary of English.
32025 You can add @command{open localhost} to your @file{~/.dico} file to make
32026 @code{localhost} the default server for @command{dico} client
32027 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
32030 @deftp {Data Type} dicod-configuration
32031 Data type representing the configuration of dicod.
32034 @item @code{dico} (default: @var{dico})
32035 Package object of the GNU Dico dictionary server.
32037 @item @code{interfaces} (default: @var{'("localhost")})
32038 This is the list of IP addresses and ports and possibly socket file
32039 names to listen to (@pxref{Server Settings, @code{listen} directive,,
32040 dico, GNU Dico Manual}).
32042 @item @code{handlers} (default: @var{'()})
32043 List of @code{<dicod-handler>} objects denoting handlers (module instances).
32045 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
32046 List of @code{<dicod-database>} objects denoting dictionaries to be served.
32050 @deftp {Data Type} dicod-handler
32051 Data type representing a dictionary handler (module instance).
32055 Name of the handler (module instance).
32057 @item @code{module} (default: @var{#f})
32058 Name of the dicod module of the handler (instance). If it is @code{#f},
32059 the module has the same name as the handler.
32060 (@pxref{Modules,,, dico, GNU Dico Manual}).
32062 @item @code{options}
32063 List of strings or gexps representing the arguments for the module handler
32067 @deftp {Data Type} dicod-database
32068 Data type representing a dictionary database.
32072 Name of the database, will be used in DICT commands.
32074 @item @code{handler}
32075 Name of the dicod handler (module instance) used by this database
32076 (@pxref{Handlers,,, dico, GNU Dico Manual}).
32078 @item @code{complex?} (default: @var{#f})
32079 Whether the database configuration complex. The complex configuration
32080 will need a corresponding @code{<dicod-handler>} object, otherwise not.
32082 @item @code{options}
32083 List of strings or gexps representing the arguments for the database
32084 (@pxref{Databases,,, dico, GNU Dico Manual}).
32088 @defvr {Scheme Variable} %dicod-database:gcide
32089 A @code{<dicod-database>} object serving the GNU Collaborative International
32090 Dictionary of English using the @code{gcide} package.
32093 The following is an example @code{dicod-service} configuration.
32096 (dicod-service #:config
32097 (dicod-configuration
32098 (handlers (list (dicod-handler
32102 (list #~(string-append "dbdir=" #$wordnet))))))
32103 (databases (list (dicod-database
32106 (handler "wordnet")
32107 (options '("database=wn")))
32108 %dicod-database:gcide))))
32112 @subsubheading Docker Service
32114 The @code{(gnu services docker)} module provides the following services.
32116 @defvr {Scheme Variable} docker-service-type
32118 This is the type of the service that runs @url{https://www.docker.com,Docker},
32119 a daemon that can execute application bundles (sometimes referred to as
32120 ``containers'') in isolated environments.
32124 @deftp {Data Type} docker-configuration
32125 This is the data type representing the configuration of Docker and Containerd.
32129 @item @code{package} (default: @code{docker})
32130 The Docker daemon package to use.
32132 @item @code{package} (default: @code{docker-cli})
32133 The Docker client package to use.
32135 @item @code{containerd} (default: @var{containerd})
32136 The Containerd package to use.
32138 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
32139 The Docker user-land networking proxy package to use.
32141 @item @code{enable-proxy?} (default @code{#t})
32142 Enable or disable the use of the Docker user-land networking proxy.
32144 @item @code{debug?} (default @code{#f})
32145 Enable or disable debug output.
32147 @item @code{enable-iptables?} (default @code{#t})
32148 Enable or disable the addition of iptables rules.
32153 @cindex Singularity, container service
32154 @defvr {Scheme Variable} singularity-service-type
32155 This is the type of the service that allows you to run
32156 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
32157 create and run application bundles (aka. ``containers''). The value for this
32158 service is the Singularity package to use.
32160 The service does not install a daemon; instead, it installs helper programs as
32161 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
32162 @command{singularity run} and similar commands.
32166 @subsubheading Auditd Service
32168 The @code{(gnu services auditd)} module provides the following service.
32170 @defvr {Scheme Variable} auditd-service-type
32172 This is the type of the service that runs
32173 @url{https://people.redhat.com/sgrubb/audit/,auditd},
32174 a daemon that tracks security-relevant information on your system.
32176 Examples of things that can be tracked:
32186 Failed login attempts
32193 @command{auditctl} from the @code{audit} package can be used in order
32194 to add or remove events to be tracked (until the next reboot).
32195 In order to permanently track events, put the command line arguments
32196 of auditctl into a file called @code{audit.rules} in the configuration
32197 directory (see below).
32198 @command{aureport} from the @code{audit} package can be used in order
32199 to view a report of all recorded events.
32200 The audit daemon by default logs into the file
32201 @file{/var/log/audit.log}.
32205 @deftp {Data Type} auditd-configuration
32206 This is the data type representing the configuration of auditd.
32210 @item @code{audit} (default: @code{audit})
32211 The audit package to use.
32213 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
32214 The directory containing the configuration file for the audit package, which
32215 must be named @code{auditd.conf}, and optionally some audit rules to
32216 instantiate on startup.
32222 @subsubheading R-Shiny service
32224 The @code{(gnu services science)} module provides the following service.
32226 @defvr {Scheme Variable} rshiny-service-type
32228 This is a type of service which is used to run a webapp created with
32229 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
32230 variable and runs the provided script to call @code{runApp}.
32232 @deftp {Data Type} rshiny-configuration
32233 This is the data type representing the configuration of rshiny.
32237 @item @code{package} (default: @code{r-shiny})
32238 The package to use.
32240 @item @code{binary} (defaunlt @code{"rshiny"})
32241 The name of the binary or shell script located at @code{package/bin/} to
32242 run when the service is run.
32244 The common way to create this file is as follows:
32248 (let* ((out (assoc-ref %outputs "out"))
32249 (targetdir (string-append out "/share/" ,name))
32250 (app (string-append out "/bin/" ,name))
32251 (Rbin (string-append (assoc-ref %build-inputs "r-min")
32254 (mkdir-p (string-append out "/bin"))
32255 (call-with-output-file app
32261 runApp(launch.browser=0, port=4202)~%\n"
32270 @subsubheading Nix service
32272 The @code{(gnu services nix)} module provides the following service.
32274 @defvr {Scheme Variable} nix-service-type
32276 This is the type of the service that runs build daemon of the
32277 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
32281 (use-modules (gnu))
32282 (use-service-modules nix)
32283 (use-package-modules package-management)
32287 (packages (append (list nix)
32290 (services (append (list (service nix-service-type))
32294 After @command{guix system reconfigure} configure Nix for your user:
32297 @item Add a Nix channel and update it. See
32298 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
32300 @item Create a symlink to your profile and activate Nix profile:
32304 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
32305 $ source /run/current-system/profile/etc/profile.d/nix.sh
32310 @deftp {Data Type} nix-configuration
32311 This data type represents the configuration of the Nix daemon.
32314 @item @code{nix} (default: @code{nix})
32315 The Nix package to use.
32317 @item @code{sandbox} (default: @code{#t})
32318 Specifies whether builds are sandboxed by default.
32320 @item @code{build-sandbox-items} (default: @code{'()})
32321 This is a list of strings or objects appended to the
32322 @code{build-sandbox-items} field of the configuration file.
32324 @item @code{extra-config} (default: @code{'()})
32325 This is a list of strings or objects appended to the configuration file.
32326 It is used to pass extra text to be added verbatim to the configuration
32329 @item @code{extra-options} (default: @code{'()})
32330 Extra command line options for @code{nix-service-type}.
32334 @node Setuid Programs
32335 @section Setuid Programs
32337 @cindex setuid programs
32338 Some programs need to run with ``root'' privileges, even when they are
32339 launched by unprivileged users. A notorious example is the
32340 @command{passwd} program, which users can run to change their
32341 password, and which needs to access the @file{/etc/passwd} and
32342 @file{/etc/shadow} files---something normally restricted to root, for
32343 obvious security reasons. To address that, these executables are
32344 @dfn{setuid-root}, meaning that they always run with root privileges
32345 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
32346 for more info about the setuid mechanism).
32348 The store itself @emph{cannot} contain setuid programs: that would be a
32349 security issue since any user on the system can write derivations that
32350 populate the store (@pxref{The Store}). Thus, a different mechanism is
32351 used: instead of changing the setuid bit directly on files that are in
32352 the store, we let the system administrator @emph{declare} which programs
32353 should be setuid root.
32355 The @code{setuid-programs} field of an @code{operating-system}
32356 declaration contains a list of G-expressions denoting the names of
32357 programs to be setuid-root (@pxref{Using the Configuration System}).
32358 For instance, the @command{passwd} program, which is part of the Shadow
32359 package, can be designated by this G-expression (@pxref{G-Expressions}):
32362 #~(string-append #$shadow "/bin/passwd")
32365 A default set of setuid programs is defined by the
32366 @code{%setuid-programs} variable of the @code{(gnu system)} module.
32368 @defvr {Scheme Variable} %setuid-programs
32369 A list of G-expressions denoting common programs that are setuid-root.
32371 The list includes commands such as @command{passwd}, @command{ping},
32372 @command{su}, and @command{sudo}.
32375 Under the hood, the actual setuid programs are created in the
32376 @file{/run/setuid-programs} directory at system activation time. The
32377 files in this directory refer to the ``real'' binaries, which are in the
32380 @node X.509 Certificates
32381 @section X.509 Certificates
32383 @cindex HTTPS, certificates
32384 @cindex X.509 certificates
32386 Web servers available over HTTPS (that is, HTTP over the transport-layer
32387 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
32388 that the client can then use to @emph{authenticate} the server. To do
32389 that, clients verify that the server's certificate is signed by a
32390 so-called @dfn{certificate authority} (CA). But to verify the CA's
32391 signature, clients must have first acquired the CA's certificate.
32393 Web browsers such as GNU@tie{}IceCat include their own set of CA
32394 certificates, such that they are able to verify CA signatures
32397 However, most other programs that can talk HTTPS---@command{wget},
32398 @command{git}, @command{w3m}, etc.---need to be told where CA
32399 certificates can be found.
32401 @cindex @code{nss-certs}
32402 In Guix, this is done by adding a package that provides certificates
32403 to the @code{packages} field of the @code{operating-system} declaration
32404 (@pxref{operating-system Reference}). Guix includes one such package,
32405 @code{nss-certs}, which is a set of CA certificates provided as part of
32406 Mozilla's Network Security Services.
32408 Note that it is @emph{not} part of @code{%base-packages}, so you need to
32409 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
32410 most applications and libraries look for certificates by default, points
32411 to the certificates installed globally.
32413 Unprivileged users, including users of Guix on a foreign distro,
32414 can also install their own certificate package in
32415 their profile. A number of environment variables need to be defined so
32416 that applications and libraries know where to find them. Namely, the
32417 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
32418 variables. Some applications add their own environment variables; for
32419 instance, the Git version control system honors the certificate bundle
32420 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
32421 would typically run something like:
32424 guix install nss-certs
32425 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
32426 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
32427 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
32430 As another example, R requires the @env{CURL_CA_BUNDLE} environment
32431 variable to point to a certificate bundle, so you would have to run
32432 something like this:
32435 guix install nss-certs
32436 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
32439 For other applications you may want to look up the required environment
32440 variable in the relevant documentation.
32443 @node Name Service Switch
32444 @section Name Service Switch
32446 @cindex name service switch
32448 The @code{(gnu system nss)} module provides bindings to the
32449 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
32450 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
32451 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
32452 extended with new ``name'' lookup methods for system databases, which
32453 includes host names, service names, user accounts, and more (@pxref{Name
32454 Service Switch, System Databases and Name Service Switch,, libc, The GNU
32455 C Library Reference Manual}).
32457 The NSS configuration specifies, for each system database, which lookup
32458 method is to be used, and how the various methods are chained
32459 together---for instance, under which circumstances NSS should try the
32460 next method in the list. The NSS configuration is given in the
32461 @code{name-service-switch} field of @code{operating-system} declarations
32462 (@pxref{operating-system Reference, @code{name-service-switch}}).
32465 @cindex .local, host name lookup
32466 As an example, the declaration below configures the NSS to use the
32467 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
32468 back-end}, which supports host name lookups over multicast DNS (mDNS)
32469 for host names ending in @code{.local}:
32472 (name-service-switch
32473 (hosts (list %files ;first, check /etc/hosts
32475 ;; If the above did not succeed, try
32476 ;; with 'mdns_minimal'.
32478 (name "mdns_minimal")
32480 ;; 'mdns_minimal' is authoritative for
32481 ;; '.local'. When it returns "not found",
32482 ;; no need to try the next methods.
32483 (reaction (lookup-specification
32484 (not-found => return))))
32486 ;; Then fall back to DNS.
32490 ;; Finally, try with the "full" 'mdns'.
32495 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
32496 contains this configuration, so you will not have to type it if all you
32497 want is to have @code{.local} host lookup working.
32499 Note that, in this case, in addition to setting the
32500 @code{name-service-switch} of the @code{operating-system} declaration,
32501 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
32502 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
32503 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
32504 to the name service cache daemon (@pxref{Base Services,
32505 @code{nscd-service}}).
32507 For convenience, the following variables provide typical NSS
32510 @defvr {Scheme Variable} %default-nss
32511 This is the default name service switch configuration, a
32512 @code{name-service-switch} object.
32515 @defvr {Scheme Variable} %mdns-host-lookup-nss
32516 This is the name service switch configuration with support for host name
32517 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
32520 The reference for name service switch configuration is given below. It
32521 is a direct mapping of the configuration file format of the C library , so
32522 please refer to the C library manual for more information (@pxref{NSS
32523 Configuration File,,, libc, The GNU C Library Reference Manual}).
32524 Compared to the configuration file format of libc NSS, it has the advantage
32525 not only of adding this warm parenthetic feel that we like, but also
32526 static checks: you will know about syntax errors and typos as soon as you
32527 run @command{guix system}.
32529 @deftp {Data Type} name-service-switch
32531 This is the data type representation the configuration of libc's name
32532 service switch (NSS). Each field below represents one of the supported
32549 The system databases handled by the NSS@. Each of these fields must be a
32550 list of @code{<name-service>} objects (see below).
32554 @deftp {Data Type} name-service
32556 This is the data type representing an actual name service and the
32557 associated lookup action.
32561 A string denoting the name service (@pxref{Services in the NSS
32562 configuration,,, libc, The GNU C Library Reference Manual}).
32564 Note that name services listed here must be visible to nscd. This is
32565 achieved by passing the @code{#:name-services} argument to
32566 @code{nscd-service} the list of packages providing the needed name
32567 services (@pxref{Base Services, @code{nscd-service}}).
32570 An action specified using the @code{lookup-specification} macro
32571 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
32572 Reference Manual}). For example:
32575 (lookup-specification (unavailable => continue)
32576 (success => return))
32581 @node Initial RAM Disk
32582 @section Initial RAM Disk
32585 @cindex initial RAM disk
32586 For bootstrapping purposes, the Linux-Libre kernel is passed an
32587 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
32588 root file system as well as an initialization script. The latter is
32589 responsible for mounting the real root file system, and for loading any
32590 kernel modules that may be needed to achieve that.
32592 The @code{initrd-modules} field of an @code{operating-system}
32593 declaration allows you to specify Linux-libre kernel modules that must
32594 be available in the initrd. In particular, this is where you would list
32595 modules needed to actually drive the hard disk where your root partition
32596 is---although the default value of @code{initrd-modules} should cover
32597 most use cases. For example, assuming you need the @code{megaraid_sas}
32598 module in addition to the default modules to be able to access your root
32599 file system, you would write:
32604 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
32607 @defvr {Scheme Variable} %base-initrd-modules
32608 This is the list of kernel modules included in the initrd by default.
32611 Furthermore, if you need lower-level customization, the @code{initrd}
32612 field of an @code{operating-system} declaration allows
32613 you to specify which initrd you would like to use. The @code{(gnu
32614 system linux-initrd)} module provides three ways to build an initrd: the
32615 high-level @code{base-initrd} procedure and the low-level
32616 @code{raw-initrd} and @code{expression->initrd} procedures.
32618 The @code{base-initrd} procedure is intended to cover most common uses.
32619 For example, if you want to add a bunch of kernel modules to be loaded
32620 at boot time, you can define the @code{initrd} field of the operating
32621 system declaration like this:
32624 (initrd (lambda (file-systems . rest)
32625 ;; Create a standard initrd but set up networking
32626 ;; with the parameters QEMU expects by default.
32627 (apply base-initrd file-systems
32628 #:qemu-networking? #t
32632 The @code{base-initrd} procedure also handles common use cases that
32633 involves using the system as a QEMU guest, or as a ``live'' system with
32634 volatile root file system.
32636 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
32637 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
32638 such as trying to guess which kernel modules and packages should be included
32639 to the initrd. An example use of @code{raw-initrd} is when a user has
32640 a custom Linux kernel configuration and default kernel modules included by
32641 @code{base-initrd} are not available.
32643 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
32644 honors several options passed on the Linux kernel command line
32645 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
32646 @code{-append} option of QEMU), notably:
32649 @item --load=@var{boot}
32650 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
32651 program, once it has mounted the root file system.
32653 Guix uses this option to yield control to a boot program that runs the
32654 service activation programs and then spawns the GNU@tie{}Shepherd, the
32655 initialization system.
32657 @item --root=@var{root}
32658 Mount @var{root} as the root file system. @var{root} can be a device
32659 name like @code{/dev/sda1}, a file system label, or a file system UUID.
32660 When unspecified, the device name from the root file system of the
32661 operating system declaration is used.
32663 @item --system=@var{system}
32664 Have @file{/run/booted-system} and @file{/run/current-system} point to
32667 @item modprobe.blacklist=@var{modules}@dots{}
32668 @cindex module, black-listing
32669 @cindex black list, of kernel modules
32670 Instruct the initial RAM disk as well as the @command{modprobe} command
32671 (from the kmod package) to refuse to load @var{modules}. @var{modules}
32672 must be a comma-separated list of module names---e.g.,
32673 @code{usbkbd,9pnet}.
32676 Start a read-eval-print loop (REPL) from the initial RAM disk before it
32677 tries to load kernel modules and to mount the root file system. Our
32678 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
32679 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
32680 Manual}, for more information on Guile's REPL.
32684 Now that you know all the features that initial RAM disks produced by
32685 @code{base-initrd} and @code{raw-initrd} provide,
32686 here is how to use it and customize it further.
32689 @cindex initial RAM disk
32690 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
32691 [#:linux-modules '()] [#:mapped-devices '()] @
32692 [#:keyboard-layout #f] @
32693 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
32694 Return a derivation that builds a raw initrd. @var{file-systems} is
32695 a list of file systems to be mounted by the initrd, possibly in addition to
32696 the root file system specified on the kernel command line via @option{--root}.
32697 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
32698 @var{mapped-devices} is a list of device mappings to realize before
32699 @var{file-systems} are mounted (@pxref{Mapped Devices}).
32700 @var{helper-packages} is a list of packages to be copied in the initrd.
32702 include @code{e2fsck/static} or other packages needed by the initrd to check
32703 the root file system.
32705 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32706 the desired console keyboard layout. This is done before @var{mapped-devices}
32707 are set up and before @var{file-systems} are mounted such that, should the
32708 user need to enter a passphrase or use the REPL, this happens using the
32709 intended keyboard layout.
32711 When @var{qemu-networking?} is true, set up networking with the standard QEMU
32712 parameters. When @var{virtio?} is true, load additional modules so that the
32713 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
32715 When @var{volatile-root?} is true, the root file system is writable but any changes
32719 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
32720 [#:mapped-devices '()] [#:keyboard-layout #f] @
32721 [#:qemu-networking? #f] [#:volatile-root? #f] @
32722 [#:linux-modules '()]
32723 Return as a file-like object a generic initrd, with kernel
32724 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
32725 mounted by the initrd, possibly in addition to the root file system specified
32726 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
32727 mappings to realize before @var{file-systems} are mounted.
32729 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32730 the desired console keyboard layout. This is done before @var{mapped-devices}
32731 are set up and before @var{file-systems} are mounted such that, should the
32732 user need to enter a passphrase or use the REPL, this happens using the
32733 intended keyboard layout.
32735 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
32737 The initrd is automatically populated with all the kernel modules necessary
32738 for @var{file-systems} and for the given options. Additional kernel
32739 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
32740 loaded at boot time in the order in which they appear.
32743 Needless to say, the initrds we produce and use embed a
32744 statically-linked Guile, and the initialization program is a Guile
32745 program. That gives a lot of flexibility. The
32746 @code{expression->initrd} procedure builds such an initrd, given the
32747 program to run in that initrd.
32749 @deffn {Scheme Procedure} expression->initrd @var{exp} @
32750 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
32751 Return as a file-like object a Linux initrd (a gzipped cpio archive)
32752 containing @var{guile} and that evaluates @var{exp}, a G-expression,
32753 upon booting. All the derivations referenced by @var{exp} are
32754 automatically copied to the initrd.
32757 @node Bootloader Configuration
32758 @section Bootloader Configuration
32761 @cindex boot loader
32763 The operating system supports multiple bootloaders. The bootloader is
32764 configured using @code{bootloader-configuration} declaration. All the
32765 fields of this structure are bootloader agnostic except for one field,
32766 @code{bootloader} that indicates the bootloader to be configured and
32769 Some of the bootloaders do not honor every field of
32770 @code{bootloader-configuration}. For instance, the extlinux
32771 bootloader does not support themes and thus ignores the @code{theme}
32774 @deftp {Data Type} bootloader-configuration
32775 The type of a bootloader configuration declaration.
32779 @item @code{bootloader}
32780 @cindex EFI, bootloader
32781 @cindex UEFI, bootloader
32782 @cindex BIOS, bootloader
32783 The bootloader to use, as a @code{bootloader} object. For now
32784 @code{grub-bootloader}, @code{grub-efi-bootloader},
32785 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
32786 @code{u-boot-bootloader} are supported.
32788 @cindex ARM, bootloaders
32789 @cindex AArch64, bootloaders
32790 Available bootloaders are described in @code{(gnu bootloader @dots{})}
32791 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
32792 of bootloaders for a wide range of ARM and AArch64 systems, using the
32793 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
32795 @vindex grub-efi-bootloader
32796 @code{grub-efi-bootloader} allows to boot on modern systems using the
32797 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
32798 use if the installation image contains a @file{/sys/firmware/efi} directory
32799 when you boot it on your system.
32801 @vindex grub-bootloader
32802 @code{grub-bootloader} allows you to boot in particular Intel-based machines
32803 in ``legacy'' BIOS mode.
32805 @vindex grub-efi-netboot-bootloader
32806 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
32807 through TFTP@. In combination with an NFS root file system this allows you to
32808 build a diskless Guix system.
32810 The installation of the @code{grub-efi-netboot-bootloader} generates the content
32811 of the TFTP root directory at @code{target}
32812 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
32813 You may want to mount your TFTP server directory onto @code{target} to move the
32814 required files to the TFTP server automatically.
32816 If you plan to use an NFS root file system as well (actually if you mount the
32817 store from an NFS share), then the TFTP server needs to serve the file
32818 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
32819 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
32820 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
32821 files from the store will be accessed by GRUB through TFTP with their normal
32822 store path, for example as
32823 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
32825 Two symlinks are created to make this possible. The first symlink is
32826 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
32827 @file{../../../boot/grub/grub.cfg},
32828 where @code{target} may be @file{/boot}. In this case the link is not leaving
32829 the served TFTP root directory, but otherwise it does. The second link is
32830 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
32831 is leaving the served TFTP root directory.
32833 The assumption behind all this is that you have an NFS server exporting the root
32834 file system for your Guix system, and additionally a TFTP server exporting your
32835 @code{target} directory—usually @file{/boot}—from that same root file system for
32836 your Guix system. In this constellation the symlinks will work.
32838 For other constellations you will have to program your own bootloader installer,
32839 which then takes care to make necessary files from the store accessible through
32840 TFTP, for example by copying them into the TFTP root directory at @code{target}.
32842 It is important to note that symlinks pointing outside the TFTP root directory
32843 may need to be allowed in the configuration of your TFTP server. Further the
32844 store link exposes the whole store through TFTP@. Both points need to be
32845 considered carefully for security aspects.
32847 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
32848 NFS servers, you also need a properly configured DHCP server to make the booting
32849 over netboot possible. For all this we can currently only recommend you to look
32850 for instructions about @acronym{PXE, Preboot eXecution Environment}.
32852 @item @code{target}
32853 This is a string denoting the target onto which to install the
32856 The interpretation depends on the bootloader in question. For
32857 @code{grub-bootloader}, for example, it should be a device name understood by
32858 the bootloader @command{installer} command, such as @code{/dev/sda} or
32859 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
32860 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
32861 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
32862 @code{target} should be the mount point corresponding to the TFTP root
32863 directory of your TFTP server.
32865 @item @code{menu-entries} (default: @code{()})
32866 A possibly empty list of @code{menu-entry} objects (see below), denoting
32867 entries to appear in the bootloader menu, in addition to the current
32868 system entry and the entry pointing to previous system generations.
32870 @item @code{default-entry} (default: @code{0})
32871 The index of the default boot menu entry. Index 0 is for the entry of the
32874 @item @code{timeout} (default: @code{5})
32875 The number of seconds to wait for keyboard input before booting. Set to
32876 0 to boot immediately, and to -1 to wait indefinitely.
32878 @cindex keyboard layout, for the bootloader
32879 @item @code{keyboard-layout} (default: @code{#f})
32880 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
32881 layout, usually US@tie{}English (``qwerty'').
32883 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
32887 This option is currently ignored by bootloaders other than @code{grub} and
32891 @item @code{theme} (default: @var{#f})
32892 The bootloader theme object describing the theme to use. If no theme
32893 is provided, some bootloaders might use a default theme, that's true
32896 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
32897 The output terminals used for the bootloader boot menu, as a list of
32898 symbols. GRUB accepts the values: @code{console}, @code{serial},
32899 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
32900 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
32901 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
32902 configuration,,, grub,GNU GRUB manual}).
32904 @item @code{terminal-inputs} (default: @code{'()})
32905 The input terminals used for the bootloader boot menu, as a list of
32906 symbols. For GRUB, the default is the native platform terminal as
32907 determined at run-time. GRUB accepts the values: @code{console},
32908 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
32909 @code{usb_keyboard}. This field corresponds to the GRUB variable
32910 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
32913 @item @code{serial-unit} (default: @code{#f})
32914 The serial unit used by the bootloader, as an integer from 0 to 3.
32915 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
32916 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32918 @item @code{serial-speed} (default: @code{#f})
32919 The speed of the serial interface, as an integer. For GRUB, the
32920 default value is chosen at run-time; currently GRUB chooses
32921 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32928 Should you want to list additional boot menu entries @i{via} the
32929 @code{menu-entries} field above, you will need to create them with the
32930 @code{menu-entry} form. For example, imagine you want to be able to
32931 boot another distro (hard to imagine!), you can define a menu entry
32936 (label "The Other Distro")
32937 (linux "/boot/old/vmlinux-2.6.32")
32938 (linux-arguments '("root=/dev/sda2"))
32939 (initrd "/boot/old/initrd"))
32944 @deftp {Data Type} menu-entry
32945 The type of an entry in the bootloader menu.
32950 The label to show in the menu---e.g., @code{"GNU"}.
32952 @item @code{linux} (default: @code{#f})
32953 The Linux kernel image to boot, for example:
32956 (file-append linux-libre "/bzImage")
32959 For GRUB, it is also possible to specify a device explicitly in the
32960 file path using GRUB's device naming convention (@pxref{Naming
32961 convention,,, grub, GNU GRUB manual}), for example:
32964 "(hd0,msdos1)/boot/vmlinuz"
32967 If the device is specified explicitly as above, then the @code{device}
32968 field is ignored entirely.
32970 @item @code{linux-arguments} (default: @code{()})
32971 The list of extra Linux kernel command-line arguments---e.g.,
32972 @code{("console=ttyS0")}.
32974 @item @code{initrd} (default: @code{#f})
32975 A G-Expression or string denoting the file name of the initial RAM disk
32976 to use (@pxref{G-Expressions}).
32978 @item @code{device} (default: @code{#f})
32979 The device where the kernel and initrd are to be found---i.e., for GRUB,
32980 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
32982 This may be a file system label (a string), a file system UUID (a
32983 bytevector, @pxref{File Systems}), or @code{#f}, in which case
32984 the bootloader will search the device containing the file specified by
32985 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
32986 must @emph{not} be an OS device name such as @file{/dev/sda1}.
32988 @item @code{multiboot-kernel} (default: @code{#f})
32989 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
32990 manual}). When this field is set, a Multiboot menu-entry is generated.
32994 (file-append mach "/boot/gnumach")
32997 @item @code{multiboot-arguments} (default: @code{()})
32998 The list of extra command-line arguments for the multiboot-kernel.
33000 @item @code{multiboot-modules} (default: @code{()})
33001 The list of commands for loading Multiboot modules. For example:
33004 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
33006 (list (file-append libc "/lib/ld.so.1") "exec"
33016 @c FIXME: Write documentation once it's stable.
33017 For now only GRUB has theme support. GRUB themes are created using
33018 the @code{grub-theme} form, which is not fully documented yet.
33020 @deftp {Data Type} grub-theme
33021 Data type representing the configuration of the GRUB theme.
33024 @item @code{gfxmode} (default: @code{'("auto")})
33025 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
33026 @pxref{gfxmode,,, grub, GNU GRUB manual}).
33030 @deffn {Scheme Procedure} grub-theme
33031 Return the default GRUB theme used by the operating system if no
33032 @code{theme} field is specified in @code{bootloader-configuration}
33035 It comes with a fancy background image displaying the GNU and Guix
33039 For example, to override the default resolution, you may use something
33044 (bootloader-configuration
33047 (inherit (grub-theme))
33048 (gfxmode '("1024x786x32" "auto"))))))
33051 @node Invoking guix system
33052 @section Invoking @code{guix system}
33054 Once you have written an operating system declaration as seen in the
33055 previous section, it can be @dfn{instantiated} using the @command{guix
33056 system} command. The synopsis is:
33059 guix system @var{options}@dots{} @var{action} @var{file}
33062 @var{file} must be the name of a file containing an
33063 @code{operating-system} declaration. @var{action} specifies how the
33064 operating system is instantiated. Currently the following values are
33069 Display available service type definitions that match the given regular
33070 expressions, sorted by relevance:
33076 $ guix system search console
33077 name: console-fonts
33078 location: gnu/services/base.scm:806:2
33079 extends: shepherd-root
33080 description: Install the given fonts on the specified ttys (fonts are per
33081 + virtual console on GNU/Linux). The value of this service is a list of
33082 + tty/font pairs. The font can be the name of a font provided by the `kbd'
33083 + package or any valid argument to `setfont', as in this example:
33085 + '(("tty1" . "LatGrkCyr-8x16")
33086 + ("tty2" . (file-append
33088 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
33089 + ("tty3" . (file-append
33091 + "/share/consolefonts/ter-132n"))) ; for HDPI
33095 location: gnu/services/base.scm:1190:2
33096 extends: shepherd-root
33097 description: Provide console login using the `mingetty' program.
33101 location: gnu/services/base.scm:860:2
33103 description: Provide a console log-in service as specified by its
33104 + configuration value, a `login-configuration' object.
33110 As for @command{guix package --search}, the result is written in
33111 @code{recutils} format, which makes it easy to filter the output
33112 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
33115 Build the operating system described in @var{file}, activate it, and
33116 switch to it@footnote{This action (and the related actions
33117 @code{switch-generation} and @code{roll-back}) are usable only on
33118 systems already running Guix System.}.
33121 @c The paragraph below refers to the problem discussed at
33122 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
33123 It is highly recommended to run @command{guix pull} once before you run
33124 @command{guix system reconfigure} for the first time (@pxref{Invoking
33125 guix pull}). Failing to do that you would see an older version of Guix
33126 once @command{reconfigure} has completed.
33129 This effects all the configuration specified in @var{file}: user
33130 accounts, system services, global package list, setuid programs, etc.
33131 The command starts system services specified in @var{file} that are not
33132 currently running; if a service is currently running this command will
33133 arrange for it to be upgraded the next time it is stopped (e.g.@: by
33134 @code{herd stop X} or @code{herd restart X}).
33136 This command creates a new generation whose number is one greater than
33137 the current generation (as reported by @command{guix system
33138 list-generations}). If that generation already exists, it will be
33139 overwritten. This behavior mirrors that of @command{guix package}
33140 (@pxref{Invoking guix package}).
33142 It also adds a bootloader menu entry for the new OS configuration,
33143 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
33144 entries for older configurations to a submenu, allowing you to choose
33145 an older system generation at boot time should you need it.
33147 @cindex provenance tracking, of the operating system
33148 Upon completion, the new system is deployed under
33149 @file{/run/current-system}. This directory contains @dfn{provenance
33150 meta-data}: the list of channels in use (@pxref{Channels}) and
33151 @var{file} itself, when available. You can view it by running:
33154 guix system describe
33157 This information is useful should you later want to inspect how this
33158 particular generation was built. In fact, assuming @var{file} is
33159 self-contained, you can later rebuild generation @var{n} of your
33160 operating system with:
33163 guix time-machine \
33164 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
33165 system reconfigure \
33166 /var/guix/profiles/system-@var{n}-link/configuration.scm
33169 You can think of it as some sort of built-in version control! Your
33170 system is not just a binary artifact: @emph{it carries its own source}.
33171 @xref{Service Reference, @code{provenance-service-type}}, for more
33172 information on provenance tracking.
33174 By default, @command{reconfigure} @emph{prevents you from downgrading
33175 your system}, which could (re)introduce security vulnerabilities and
33176 also cause problems with ``stateful'' services such as database
33177 management systems. You can override that behavior by passing
33178 @option{--allow-downgrades}.
33180 @item switch-generation
33181 @cindex generations
33182 Switch to an existing system generation. This action atomically
33183 switches the system profile to the specified system generation. It
33184 also rearranges the system's existing bootloader menu entries. It
33185 makes the menu entry for the specified system generation the default,
33186 and it moves the entries for the other generations to a submenu, if
33187 supported by the bootloader being used. The next time the system
33188 boots, it will use the specified system generation.
33190 The bootloader itself is not being reinstalled when using this
33191 command. Thus, the installed bootloader is used with an updated
33192 configuration file.
33194 The target generation can be specified explicitly by its generation
33195 number. For example, the following invocation would switch to system
33199 guix system switch-generation 7
33202 The target generation can also be specified relative to the current
33203 generation with the form @code{+N} or @code{-N}, where @code{+3} means
33204 ``3 generations ahead of the current generation,'' and @code{-1} means
33205 ``1 generation prior to the current generation.'' When specifying a
33206 negative value such as @code{-1}, you must precede it with @code{--} to
33207 prevent it from being parsed as an option. For example:
33210 guix system switch-generation -- -1
33213 Currently, the effect of invoking this action is @emph{only} to switch
33214 the system profile to an existing generation and rearrange the
33215 bootloader menu entries. To actually start using the target system
33216 generation, you must reboot after running this action. In the future,
33217 it will be updated to do the same things as @command{reconfigure},
33218 like activating and deactivating services.
33220 This action will fail if the specified generation does not exist.
33223 @cindex rolling back
33224 Switch to the preceding system generation. The next time the system
33225 boots, it will use the preceding system generation. This is the inverse
33226 of @command{reconfigure}, and it is exactly the same as invoking
33227 @command{switch-generation} with an argument of @code{-1}.
33229 Currently, as with @command{switch-generation}, you must reboot after
33230 running this action to actually start using the preceding system
33233 @item delete-generations
33234 @cindex deleting system generations
33235 @cindex saving space
33236 Delete system generations, making them candidates for garbage collection
33237 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
33240 This works in the same way as @samp{guix package --delete-generations}
33241 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
33242 arguments, all system generations but the current one are deleted:
33245 guix system delete-generations
33248 You can also select the generations you want to delete. The example below
33249 deletes all the system generations that are more than two month old:
33252 guix system delete-generations 2m
33255 Running this command automatically reinstalls the bootloader with an updated
33256 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
33257 longer lists the generations that have been deleted.
33260 Build the derivation of the operating system, which includes all the
33261 configuration files and programs needed to boot and run the system.
33262 This action does not actually install anything.
33265 Populate the given directory with all the files necessary to run the
33266 operating system specified in @var{file}. This is useful for first-time
33267 installations of Guix System. For instance:
33270 guix system init my-os-config.scm /mnt
33273 copies to @file{/mnt} all the store items required by the configuration
33274 specified in @file{my-os-config.scm}. This includes configuration
33275 files, packages, and so on. It also creates other essential files
33276 needed for the system to operate correctly---e.g., the @file{/etc},
33277 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
33279 This command also installs bootloader on the target specified in
33280 @file{my-os-config}, unless the @option{--no-bootloader} option was
33284 @cindex virtual machine
33286 @anchor{guix system vm}
33287 Build a virtual machine that contains the operating system declared in
33288 @var{file}, and return a script to run that virtual machine (VM).
33291 The @code{vm} action and others below
33292 can use KVM support in the Linux-libre kernel. Specifically, if the
33293 machine has hardware virtualization support, the corresponding
33294 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
33295 must exist and be readable and writable by the user and by the
33296 build users of the daemon (@pxref{Build Environment Setup}).
33299 Arguments given to the script are passed to QEMU as in the example
33300 below, which enables networking and requests 1@tie{}GiB of RAM for the
33304 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -nic user,model=virtio-net-pci
33307 The VM shares its store with the host system.
33309 Additional file systems can be shared between the host and the VM using
33310 the @option{--share} and @option{--expose} command-line options: the former
33311 specifies a directory to be shared with write access, while the latter
33312 provides read-only access to the shared directory.
33314 The example below creates a VM in which the user's home directory is
33315 accessible read-only, and where the @file{/exchange} directory is a
33316 read-write mapping of @file{$HOME/tmp} on the host:
33319 guix system vm my-config.scm \
33320 --expose=$HOME --share=$HOME/tmp=/exchange
33323 On GNU/Linux, the default is to boot directly to the kernel; this has
33324 the advantage of requiring only a very tiny root disk image since the
33325 store of the host can then be mounted.
33327 The @option{--full-boot} option forces a complete boot sequence, starting
33328 with the bootloader. This requires more disk space since a root image
33329 containing at least the kernel, initrd, and bootloader data files must
33330 be created. The @option{--image-size} option can be used to specify the
33333 @cindex System images, creation in various formats
33334 @cindex Creating system images in various formats
33336 @itemx docker-image
33337 Return a virtual machine, disk image, or Docker image of the operating
33338 system declared in @var{file} that stands alone. By default,
33339 @command{guix system} estimates the size of the image needed to store
33340 the system, but you can use the @option{--image-size} option to specify
33341 a value. Docker images are built to contain exactly what they need, so
33342 the @option{--image-size} option is ignored in the case of
33343 @code{docker-image}.
33345 @cindex image, creating disk images
33346 The @code{image} command can produce various image types. The
33347 image type can be selected using the @option{--image-type} option. It
33348 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
33349 @option{--label} option can be used to specify a volume ID with
33350 @code{image}. By default, the root file system of a disk image is
33351 mounted non-volatile; the @option{--volatile} option can be provided to
33352 make it volatile instead. When using @code{image}, the bootloader
33353 installed on the generated image is taken from the provided
33354 @code{operating-system} definition. The following example demonstrates
33355 how to generate an image that uses the @code{grub-efi-bootloader}
33356 bootloader and boot it with QEMU:
33359 image=$(guix system image --image-type=qcow2 \
33360 gnu/system/examples/lightweight-desktop.tmpl)
33361 cp $image /tmp/my-image.qcow2
33362 chmod +w /tmp/my-image.qcow2
33363 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
33364 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
33367 When using the @code{efi-raw} image type, a raw disk image is produced;
33368 it can be copied as is to a USB stick, for instance. Assuming
33369 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
33370 the image to it using the following command:
33373 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
33376 The @code{--list-image-types} command lists all the available image
33379 @cindex creating virtual machine images
33380 When using the @code{qcow2} image type, the returned image is in qcow2
33381 format, which the QEMU emulator can efficiently use. @xref{Running Guix
33382 in a VM}, for more information on how to run the image in a virtual
33383 machine. The @code{grub-bootloader} bootloader is always used
33384 independently of what is declared in the @code{operating-system} file
33385 passed as argument. This is to make it easier to work with QEMU, which
33386 uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
33387 in the Master Boot Record (MBR).
33389 @cindex docker-image, creating docker images
33390 When using @code{docker-image}, a Docker image is produced. Guix builds
33391 the image from scratch, not from a pre-existing Docker base image. As a
33392 result, it contains @emph{exactly} what you define in the operating
33393 system configuration file. You can then load the image and launch a
33394 Docker container using commands like the following:
33397 image_id="$(docker load < guix-system-docker-image.tar.gz)"
33398 container_id="$(docker create $image_id)"
33399 docker start $container_id
33402 This command starts a new Docker container from the specified image. It
33403 will boot the Guix system in the usual manner, which means it will
33404 start any services you have defined in the operating system
33405 configuration. You can get an interactive shell running in the container
33406 using @command{docker exec}:
33409 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
33412 Depending on what you run in the Docker container, it
33413 may be necessary to give the container additional permissions. For
33414 example, if you intend to build software using Guix inside of the Docker
33415 container, you may need to pass the @option{--privileged} option to
33416 @code{docker create}.
33418 Last, the @option{--network} option applies to @command{guix system
33419 docker-image}: it produces an image where network is supposedly shared
33420 with the host, and thus without services like nscd or NetworkManager.
33423 Return a script to run the operating system declared in @var{file}
33424 within a container. Containers are a set of lightweight isolation
33425 mechanisms provided by the kernel Linux-libre. Containers are
33426 substantially less resource-demanding than full virtual machines since
33427 the kernel, shared objects, and other resources can be shared with the
33428 host system; this also means they provide thinner isolation.
33430 Currently, the script must be run as root in order to support more than
33431 a single user and group. The container shares its store with the host
33434 As with the @code{vm} action (@pxref{guix system vm}), additional file
33435 systems to be shared between the host and container can be specified
33436 using the @option{--share} and @option{--expose} options:
33439 guix system container my-config.scm \
33440 --expose=$HOME --share=$HOME/tmp=/exchange
33444 This option requires Linux-libre 3.19 or newer.
33449 @var{options} can contain any of the common build options (@pxref{Common
33450 Build Options}). In addition, @var{options} can contain one of the
33454 @item --expression=@var{expr}
33455 @itemx -e @var{expr}
33456 Consider the operating-system @var{expr} evaluates to.
33457 This is an alternative to specifying a file which evaluates to an
33459 This is used to generate the Guix system installer @pxref{Building the
33460 Installation Image}).
33462 @item --system=@var{system}
33463 @itemx -s @var{system}
33464 Attempt to build for @var{system} instead of the host system type.
33465 This works as per @command{guix build} (@pxref{Invoking guix build}).
33469 Return the derivation file name of the given operating system without
33472 @cindex provenance tracking, of the operating system
33473 @item --save-provenance
33474 As discussed above, @command{guix system init} and @command{guix system
33475 reconfigure} always save provenance information @i{via} a dedicated
33476 service (@pxref{Service Reference, @code{provenance-service-type}}).
33477 However, other commands don't do that by default. If you wish to, say,
33478 create a virtual machine image that contains provenance information, you
33482 guix system image -t qcow2 --save-provenance config.scm
33485 That way, the resulting image will effectively ``embed its own source''
33486 in the form of meta-data in @file{/run/current-system}. With that
33487 information, one can rebuild the image to make sure it really contains
33488 what it pretends to contain; or they could use that to derive a variant
33491 @item --image-type=@var{type}
33492 @itemx -t @var{type}
33493 For the @code{image} action, create an image with given @var{type}.
33495 When this option is omitted, @command{guix system} uses the
33496 @code{efi-raw} image type.
33498 @cindex ISO-9660 format
33499 @cindex CD image format
33500 @cindex DVD image format
33501 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
33502 for burning on CDs and DVDs.
33504 @item --image-size=@var{size}
33505 For the @code{image} action, create an image of the given @var{size}.
33506 @var{size} may be a number of bytes, or it may include a unit as a
33507 suffix (@pxref{Block size, size specifications,, coreutils, GNU
33510 When this option is omitted, @command{guix system} computes an estimate
33511 of the image size as a function of the size of the system declared in
33516 For the @code{container} action, allow containers to access the host network,
33517 that is, do not create a network namespace.
33519 @item --root=@var{file}
33520 @itemx -r @var{file}
33521 Make @var{file} a symlink to the result, and register it as a garbage
33524 @item --skip-checks
33525 Skip pre-installation safety checks.
33527 By default, @command{guix system init} and @command{guix system
33528 reconfigure} perform safety checks: they make sure the file systems that
33529 appear in the @code{operating-system} declaration actually exist
33530 (@pxref{File Systems}), and that any Linux kernel modules that may be
33531 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
33532 RAM Disk}). Passing this option skips these tests altogether.
33534 @item --allow-downgrades
33535 Instruct @command{guix system reconfigure} to allow system downgrades.
33537 By default, @command{reconfigure} prevents you from downgrading your
33538 system. It achieves that by comparing the provenance info of your
33539 system (shown by @command{guix system describe}) with that of your
33540 @command{guix} command (shown by @command{guix describe}). If the
33541 commits for @command{guix} are not descendants of those used for your
33542 system, @command{guix system reconfigure} errors out. Passing
33543 @option{--allow-downgrades} allows you to bypass these checks.
33546 Make sure you understand its security implications before using
33547 @option{--allow-downgrades}.
33551 @cindex on-error strategy
33552 @cindex error strategy
33553 @item --on-error=@var{strategy}
33554 Apply @var{strategy} when an error occurs when reading @var{file}.
33555 @var{strategy} may be one of the following:
33558 @item nothing-special
33559 Report the error concisely and exit. This is the default strategy.
33562 Likewise, but also display a backtrace.
33565 Report the error and enter Guile's debugger. From there, you can run
33566 commands such as @code{,bt} to get a backtrace, @code{,locals} to
33567 display local variable values, and more generally inspect the state of the
33568 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
33569 a list of available debugging commands.
33573 Once you have built, configured, re-configured, and re-re-configured
33574 your Guix installation, you may find it useful to list the operating
33575 system generations available on disk---and that you can choose from the
33576 bootloader boot menu:
33581 Describe the current system generation: its file name, the kernel and
33582 bootloader used, etc., as well as provenance information when available.
33584 @item list-generations
33585 List a summary of each generation of the operating system available on
33586 disk, in a human-readable way. This is similar to the
33587 @option{--list-generations} option of @command{guix package}
33588 (@pxref{Invoking guix package}).
33590 Optionally, one can specify a pattern, with the same syntax that is used
33591 in @command{guix package --list-generations}, to restrict the list of
33592 generations displayed. For instance, the following command displays
33593 generations that are up to 10 days old:
33596 $ guix system list-generations 10d
33601 The @command{guix system} command has even more to offer! The following
33602 sub-commands allow you to visualize how your system services relate to
33605 @anchor{system-extension-graph}
33608 @item extension-graph
33609 Emit to standard output the @dfn{service
33610 extension graph} of the operating system defined in @var{file}
33611 (@pxref{Service Composition}, for more information on service
33612 extensions). By default the output is in Dot/Graphviz format, but you
33613 can choose a different format with @option{--graph-backend}, as with
33614 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
33619 $ guix system extension-graph @var{file} | xdot -
33622 shows the extension relations among services.
33624 @anchor{system-shepherd-graph}
33625 @item shepherd-graph
33626 Emit to standard output the @dfn{dependency
33627 graph} of shepherd services of the operating system defined in
33628 @var{file}. @xref{Shepherd Services}, for more information and for an
33631 Again, the default output format is Dot/Graphviz, but you can pass
33632 @option{--graph-backend} to select a different one.
33636 @node Invoking guix deploy
33637 @section Invoking @code{guix deploy}
33639 We've already seen @code{operating-system} declarations used to manage a
33640 machine's configuration locally. Suppose you need to configure multiple
33641 machines, though---perhaps you're managing a service on the web that's
33642 comprised of several servers. @command{guix deploy} enables you to use those
33643 same @code{operating-system} declarations to manage multiple remote hosts at
33644 once as a logical ``deployment''.
33647 The functionality described in this section is still under development
33648 and is subject to change. Get in touch with us on
33649 @email{guix-devel@@gnu.org}!
33653 guix deploy @var{file}
33656 Such an invocation will deploy the machines that the code within @var{file}
33657 evaluates to. As an example, @var{file} might contain a definition like this:
33660 ;; This is a Guix deployment of a "bare bones" setup, with
33661 ;; no X11 display server, to a machine with an SSH daemon
33662 ;; listening on localhost:2222. A configuration such as this
33663 ;; may be appropriate for virtual machine with ports
33664 ;; forwarded to the host's loopback interface.
33666 (use-service-modules networking ssh)
33667 (use-package-modules bootloaders)
33671 (host-name "gnu-deployed")
33672 (timezone "Etc/UTC")
33673 (bootloader (bootloader-configuration
33674 (bootloader grub-bootloader)
33675 (target "/dev/vda")
33676 (terminal-outputs '(console))))
33677 (file-systems (cons (file-system
33679 (device "/dev/vda1")
33681 %base-file-systems))
33683 (append (list (service dhcp-client-service-type)
33684 (service openssh-service-type
33685 (openssh-configuration
33686 (permit-root-login #t)
33687 (allow-empty-passwords? #t))))
33691 (operating-system %system)
33692 (environment managed-host-environment-type)
33693 (configuration (machine-ssh-configuration
33694 (host-name "localhost")
33695 (system "x86_64-linux")
33697 (identity "./id_rsa")
33701 The file should evaluate to a list of @var{machine} objects. This example,
33702 upon being deployed, will create a new generation on the remote system
33703 realizing the @code{operating-system} declaration @code{%system}.
33704 @code{environment} and @code{configuration} specify how the machine should be
33705 provisioned---that is, how the computing resources should be created and
33706 managed. The above example does not create any resources, as a
33707 @code{'managed-host} is a machine that is already running the Guix system and
33708 available over the network. This is a particularly simple case; a more
33709 complex deployment may involve, for example, starting virtual machines through
33710 a Virtual Private Server (VPS) provider. In such a case, a different
33711 @var{environment} type would be used.
33713 Do note that you first need to generate a key pair on the coordinator machine
33714 to allow the daemon to export signed archives of files from the store
33715 (@pxref{Invoking guix archive}), though this step is automatic on Guix
33719 # guix archive --generate-key
33723 Each target machine must authorize the key of the master machine so that it
33724 accepts store items it receives from the coordinator:
33727 # guix archive --authorize < coordinator-public-key.txt
33730 @code{user}, in this example, specifies the name of the user account to log in
33731 as to perform the deployment. Its default value is @code{root}, but root
33732 login over SSH may be forbidden in some cases. To work around this,
33733 @command{guix deploy} can log in as an unprivileged user and employ
33734 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
33735 currently installed on the remote and can be invoked non-interactively as
33736 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
33737 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
33738 be accomplished with the following operating system configuration snippet:
33742 (gnu system)) ;for %sudoers-specification
33744 (define %user "username")
33749 (plain-file "sudoers"
33750 (string-append (plain-file-content %sudoers-specification)
33751 (format #f "~a ALL = NOPASSWD: ALL~%"
33756 For more information regarding the format of the @file{sudoers} file,
33757 consult @command{man sudoers}.
33759 @deftp {Data Type} machine
33760 This is the data type representing a single machine in a heterogeneous Guix
33764 @item @code{operating-system}
33765 The object of the operating system configuration to deploy.
33767 @item @code{environment}
33768 An @code{environment-type} describing how the machine should be provisioned.
33770 @item @code{configuration} (default: @code{#f})
33771 An object describing the configuration for the machine's @code{environment}.
33772 If the @code{environment} has a default configuration, @code{#f} may be used.
33773 If @code{#f} is used for an environment with no default configuration,
33774 however, an error will be thrown.
33778 @deftp {Data Type} machine-ssh-configuration
33779 This is the data type representing the SSH client parameters for a machine
33780 with an @code{environment} of @code{managed-host-environment-type}.
33783 @item @code{host-name}
33784 @item @code{build-locally?} (default: @code{#t})
33785 If false, system derivations will be built on the machine being deployed to.
33786 @item @code{system}
33787 The system type describing the architecture of the machine being deployed
33788 to---e.g., @code{"x86_64-linux"}.
33789 @item @code{authorize?} (default: @code{#t})
33790 If true, the coordinator's signing key will be added to the remote's ACL
33792 @item @code{port} (default: @code{22})
33793 @item @code{user} (default: @code{"root"})
33794 @item @code{identity} (default: @code{#f})
33795 If specified, the path to the SSH private key to use to authenticate with the
33798 @item @code{host-key} (default: @code{#f})
33799 This should be the SSH host key of the machine, which looks like this:
33802 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
33805 When @code{host-key} is @code{#f}, the server is authenticated against
33806 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
33809 @item @code{allow-downgrades?} (default: @code{#f})
33810 Whether to allow potential downgrades.
33812 Like @command{guix system reconfigure}, @command{guix deploy} compares
33813 the channel commits currently deployed on the remote host (as returned
33814 by @command{guix system describe}) to those currently in use (as
33815 returned by @command{guix describe}) to determine whether commits
33816 currently in use are descendants of those deployed. When this is not
33817 the case and @code{allow-downgrades?} is false, it raises an error.
33818 This ensures you do not accidentally downgrade remote machines.
33822 @deftp {Data Type} digital-ocean-configuration
33823 This is the data type describing the Droplet that should be created for a
33824 machine with an @code{environment} of @code{digital-ocean-environment-type}.
33827 @item @code{ssh-key}
33828 The path to the SSH private key to use to authenticate with the remote
33829 host. In the future, this field may not exist.
33831 A list of string ``tags'' that uniquely identify the machine. Must be given
33832 such that no two machines in the deployment have the same set of tags.
33833 @item @code{region}
33834 A Digital Ocean region slug, such as @code{"nyc3"}.
33836 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
33837 @item @code{enable-ipv6?}
33838 Whether or not the droplet should be created with IPv6 networking.
33842 @node Running Guix in a VM
33843 @section Running Guix in a Virtual Machine
33845 @cindex virtual machine
33846 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM
33847 image distributed at
33848 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.qcow2}.
33849 This image is a compressed image in QCOW format. You can pass it to an
33850 emulator such as @uref{https://qemu.org/, QEMU} (see below for details).
33852 This image boots the Xfce graphical environment and it contains some
33853 commonly used tools. You can install more software in the image by running
33854 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
33855 also reconfigure the system based on its initial configuration file available
33856 as @file{/run/current-system/configuration.scm} (@pxref{Using the
33857 Configuration System}).
33859 Instead of using this pre-built image, one can also build their own
33860 image using @command{guix system image} (@pxref{Invoking guix system}).
33863 If you built your own image, you must copy it out of the store
33864 (@pxref{The Store}) and give yourself permission to write to the copy
33865 before you can use it. When invoking QEMU, you must choose a system
33866 emulator that is suitable for your hardware platform. Here is a minimal
33867 QEMU invocation that will boot the result of @command{guix system
33868 image -t qcow2} on x86_64 hardware:
33871 $ qemu-system-x86_64 \
33872 -nic user,model=virtio-net-pci \
33873 -enable-kvm -m 1024 \
33874 -device virtio-blk,drive=myhd \
33875 -drive if=none,file=/tmp/qemu-image,id=myhd
33878 Here is what each of these options means:
33881 @item qemu-system-x86_64
33882 This specifies the hardware platform to emulate. This should match the
33885 @item -nic user,model=virtio-net-pci
33886 Enable the unprivileged user-mode network stack. The guest OS can
33887 access the host but not vice versa. This is the simplest way to get the
33888 guest OS online. @code{model} specifies which network device to emulate:
33889 @code{virtio-net-pci} is a special device made for virtualized operating
33890 systems and recommended for most uses. Assuming your hardware platform is
33891 x86_64, you can get a list of available NIC models by running
33892 @command{qemu-system-x86_64 -nic model=help}.
33895 If your system has hardware virtualization extensions, enabling the
33896 virtual machine support (KVM) of the Linux kernel will make things run
33899 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
33901 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
33902 which may be insufficient for some operations.
33904 @item -device virtio-blk,drive=myhd
33905 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
33906 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
33907 better performance than if it were emulating a complete disk drive. See the
33908 QEMU and KVM documentation for more info.
33910 @item -drive if=none,file=/tmp/qemu-image,id=myhd
33911 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
33912 store of the ``myhd'' drive.
33915 The default @command{run-vm.sh} script that is returned by an invocation of
33916 @command{guix system vm} does not add a @command{-nic user} flag by default.
33917 To get network access from within the vm add the @code{(dhcp-client-service)}
33918 to your system definition and start the VM using
33919 @command{$(guix system vm config.scm) -nic user}. An important caveat of using
33920 @command{-nic user} for networking is that @command{ping} will not work, because
33921 it uses the ICMP protocol. You'll have to use a different command to check for
33922 network connectivity, for example @command{guix download}.
33924 @subsection Connecting Through SSH
33928 To enable SSH inside a VM you need to add an SSH server like
33929 @code{openssh-service-type} to your VM (@pxref{Networking Services,
33930 @code{openssh-service-type}}). In addition you need to forward the SSH port,
33931 22 by default, to the host. You can do this with
33934 $(guix system vm config.scm) -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
33937 To connect to the VM you can run
33940 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022 localhost
33943 The @command{-p} tells @command{ssh} the port you want to connect to.
33944 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
33945 every time you modify your @command{config.scm} file and the
33946 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
33947 connection to an unknown host every time you connect.
33950 If you find the above @samp{hostfwd} example not to be working (e.g.,
33951 your SSH client hangs attempting to connect to the mapped port of your
33952 VM), make sure that your Guix System VM has networking support, such as
33953 by using the @code{dhcp-client-service-type} service type.
33956 @subsection Using @command{virt-viewer} with Spice
33958 As an alternative to the default @command{qemu} graphical client you can
33959 use the @command{remote-viewer} from the @command{virt-viewer} package. To
33960 connect pass the @command{-spice port=5930,disable-ticketing} flag to
33961 @command{qemu}. See previous section for further information on how to do this.
33963 Spice also allows you to do some nice stuff like share your clipboard with your
33964 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
33967 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
33968 -chardev spicevmc,name=vdagent,id=vdagent
33969 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
33970 name=com.redhat.spice.0
33973 You'll also need to add the @code{(spice-vdagent-service)} to your
33974 system definition (@pxref{Miscellaneous Services, Spice service}).
33976 @node Defining Services
33977 @section Defining Services
33979 The previous sections show the available services and how one can combine
33980 them in an @code{operating-system} declaration. But how do we define
33981 them in the first place? And what is a service anyway?
33984 * Service Composition:: The model for composing services.
33985 * Service Types and Services:: Types and services.
33986 * Service Reference:: API reference.
33987 * Shepherd Services:: A particular type of service.
33990 @node Service Composition
33991 @subsection Service Composition
33995 Here we define a @dfn{service} as, broadly, something that extends the
33996 functionality of the operating system. Often a service is a process---a
33997 @dfn{daemon}---started when the system boots: a secure shell server, a
33998 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
33999 whose execution can be triggered by another daemon---e.g., an FTP server
34000 started by @command{inetd} or a D-Bus service activated by
34001 @command{dbus-daemon}. Occasionally, a service does not map to a
34002 daemon. For instance, the ``account'' service collects user accounts
34003 and makes sure they exist when the system runs; the ``udev'' service
34004 collects device management rules and makes them available to the eudev
34005 daemon; the @file{/etc} service populates the @file{/etc} directory
34008 @cindex service extensions
34009 Guix system services are connected by @dfn{extensions}. For instance, the
34010 secure shell service @emph{extends} the Shepherd---the
34011 initialization system, running as PID@tie{}1---by giving it the command
34012 lines to start and stop the secure shell daemon (@pxref{Networking
34013 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
34014 service by passing it its @file{.service} specification, and extends the
34015 udev service by passing it device management rules (@pxref{Desktop
34016 Services, @code{upower-service}}); the Guix daemon service extends the
34017 Shepherd by passing it the command lines to start and stop the daemon,
34018 and extends the account service by passing it a list of required build
34019 user accounts (@pxref{Base Services}).
34021 All in all, services and their ``extends'' relations form a directed
34022 acyclic graph (DAG). If we represent services as boxes and extensions
34023 as arrows, a typical system might provide something like this:
34025 @image{images/service-graph,,5in,Typical service extension graph.}
34027 @cindex system service
34028 At the bottom, we see the @dfn{system service}, which produces the
34029 directory containing everything to run and boot the system, as returned
34030 by the @command{guix system build} command. @xref{Service Reference},
34031 to learn about the other service types shown here.
34032 @xref{system-extension-graph, the @command{guix system extension-graph}
34033 command}, for information on how to generate this representation for a
34034 particular operating system definition.
34036 @cindex service types
34037 Technically, developers can define @dfn{service types} to express these
34038 relations. There can be any number of services of a given type on the
34039 system---for instance, a system running two instances of the GNU secure
34040 shell server (lsh) has two instances of @code{lsh-service-type}, with
34041 different parameters.
34043 The following section describes the programming interface for service
34044 types and services.
34046 @node Service Types and Services
34047 @subsection Service Types and Services
34049 A @dfn{service type} is a node in the DAG described above. Let us start
34050 with a simple example, the service type for the Guix build daemon
34051 (@pxref{Invoking guix-daemon}):
34054 (define guix-service-type
34058 (list (service-extension shepherd-root-service-type guix-shepherd-service)
34059 (service-extension account-service-type guix-accounts)
34060 (service-extension activation-service-type guix-activation)))
34061 (default-value (guix-configuration))))
34065 It defines three things:
34069 A name, whose sole purpose is to make inspection and debugging easier.
34072 A list of @dfn{service extensions}, where each extension designates the
34073 target service type and a procedure that, given the parameters of the
34074 service, returns a list of objects to extend the service of that type.
34076 Every service type has at least one service extension. The only
34077 exception is the @dfn{boot service type}, which is the ultimate service.
34080 Optionally, a default value for instances of this type.
34083 In this example, @code{guix-service-type} extends three services:
34086 @item shepherd-root-service-type
34087 The @code{guix-shepherd-service} procedure defines how the Shepherd
34088 service is extended. Namely, it returns a @code{<shepherd-service>}
34089 object that defines how @command{guix-daemon} is started and stopped
34090 (@pxref{Shepherd Services}).
34092 @item account-service-type
34093 This extension for this service is computed by @code{guix-accounts},
34094 which returns a list of @code{user-group} and @code{user-account}
34095 objects representing the build user accounts (@pxref{Invoking
34098 @item activation-service-type
34099 Here @code{guix-activation} is a procedure that returns a gexp, which is
34100 a code snippet to run at ``activation time''---e.g., when the service is
34104 A service of this type is instantiated like this:
34107 (service guix-service-type
34108 (guix-configuration
34110 (extra-options '("--gc-keep-derivations"))))
34113 The second argument to the @code{service} form is a value representing
34114 the parameters of this specific service instance.
34115 @xref{guix-configuration-type, @code{guix-configuration}}, for
34116 information about the @code{guix-configuration} data type. When the
34117 value is omitted, the default value specified by
34118 @code{guix-service-type} is used:
34121 (service guix-service-type)
34124 @code{guix-service-type} is quite simple because it extends other
34125 services but is not extensible itself.
34127 @c @subsubsubsection Extensible Service Types
34129 The service type for an @emph{extensible} service looks like this:
34132 (define udev-service-type
34133 (service-type (name 'udev)
34135 (list (service-extension shepherd-root-service-type
34136 udev-shepherd-service)))
34138 (compose concatenate) ;concatenate the list of rules
34139 (extend (lambda (config rules)
34141 (($ <udev-configuration> udev initial-rules)
34142 (udev-configuration
34143 (udev udev) ;the udev package to use
34144 (rules (append initial-rules rules)))))))))
34147 This is the service type for the
34148 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
34149 management daemon}. Compared to the previous example, in addition to an
34150 extension of @code{shepherd-root-service-type}, we see two new fields:
34154 This is the procedure to @dfn{compose} the list of extensions to
34155 services of this type.
34157 Services can extend the udev service by passing it lists of rules; we
34158 compose those extensions simply by concatenating them.
34161 This procedure defines how the value of the service is @dfn{extended} with
34162 the composition of the extensions.
34164 Udev extensions are composed into a list of rules, but the udev service
34165 value is itself a @code{<udev-configuration>} record. So here, we
34166 extend that record by appending the list of rules it contains to the
34167 list of contributed rules.
34170 This is a string giving an overview of the service type. The string can
34171 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
34172 @command{guix system search} command searches these strings and displays
34173 them (@pxref{Invoking guix system}).
34176 There can be only one instance of an extensible service type such as
34177 @code{udev-service-type}. If there were more, the
34178 @code{service-extension} specifications would be ambiguous.
34180 Still here? The next section provides a reference of the programming
34181 interface for services.
34183 @node Service Reference
34184 @subsection Service Reference
34186 We have seen an overview of service types (@pxref{Service Types and
34187 Services}). This section provides a reference on how to manipulate
34188 services and service types. This interface is provided by the
34189 @code{(gnu services)} module.
34191 @deffn {Scheme Procedure} service @var{type} [@var{value}]
34192 Return a new service of @var{type}, a @code{<service-type>} object (see
34193 below). @var{value} can be any object; it represents the parameters of
34194 this particular service instance.
34196 When @var{value} is omitted, the default value specified by @var{type}
34197 is used; if @var{type} does not specify a default value, an error is
34200 For instance, this:
34203 (service openssh-service-type)
34207 is equivalent to this:
34210 (service openssh-service-type
34211 (openssh-configuration))
34214 In both cases the result is an instance of @code{openssh-service-type}
34215 with the default configuration.
34218 @deffn {Scheme Procedure} service? @var{obj}
34219 Return true if @var{obj} is a service.
34222 @deffn {Scheme Procedure} service-kind @var{service}
34223 Return the type of @var{service}---i.e., a @code{<service-type>} object.
34226 @deffn {Scheme Procedure} service-value @var{service}
34227 Return the value associated with @var{service}. It represents its
34231 Here is an example of how a service is created and manipulated:
34235 (service nginx-service-type
34236 (nginx-configuration
34238 (log-directory log-directory)
34239 (run-directory run-directory)
34240 (file config-file))))
34245 (eq? (service-kind s) nginx-service-type)
34249 The @code{modify-services} form provides a handy way to change the
34250 parameters of some of the services of a list such as
34251 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
34252 evaluates to a list of services. Of course, you could always use
34253 standard list combinators such as @code{map} and @code{fold} to do that
34254 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
34255 @code{modify-services} simply provides a more concise form for this
34258 @deffn {Scheme Syntax} modify-services @var{services} @
34259 (@var{type} @var{variable} => @var{body}) @dots{}
34261 Modify the services listed in @var{services} according to the given
34262 clauses. Each clause has the form:
34265 (@var{type} @var{variable} => @var{body})
34268 where @var{type} is a service type---e.g.,
34269 @code{guix-service-type}---and @var{variable} is an identifier that is
34270 bound within the @var{body} to the service parameters---e.g., a
34271 @code{guix-configuration} instance---of the original service of that
34274 The @var{body} should evaluate to the new service parameters, which will
34275 be used to configure the new service. This new service will replace the
34276 original in the resulting list. Because a service's service parameters
34277 are created using @code{define-record-type*}, you can write a succinct
34278 @var{body} that evaluates to the new service parameters by using the
34279 @code{inherit} feature that @code{define-record-type*} provides.
34281 @xref{Using the Configuration System}, for example usage.
34285 Next comes the programming interface for service types. This is
34286 something you want to know when writing new service definitions, but not
34287 necessarily when simply looking for ways to customize your
34288 @code{operating-system} declaration.
34290 @deftp {Data Type} service-type
34291 @cindex service type
34292 This is the representation of a @dfn{service type} (@pxref{Service Types
34297 This is a symbol, used only to simplify inspection and debugging.
34299 @item @code{extensions}
34300 A non-empty list of @code{<service-extension>} objects (see below).
34302 @item @code{compose} (default: @code{#f})
34303 If this is @code{#f}, then the service type denotes services that cannot
34304 be extended---i.e., services that do not receive ``values'' from other
34307 Otherwise, it must be a one-argument procedure. The procedure is called
34308 by @code{fold-services} and is passed a list of values collected from
34309 extensions. It may return any single value.
34311 @item @code{extend} (default: @code{#f})
34312 If this is @code{#f}, services of this type cannot be extended.
34314 Otherwise, it must be a two-argument procedure: @code{fold-services}
34315 calls it, passing it the initial value of the service as the first
34316 argument and the result of applying @code{compose} to the extension
34317 values as the second argument. It must return a value that is a valid
34318 parameter value for the service instance.
34320 @item @code{description}
34321 This is a string, possibly using Texinfo markup, describing in a couple
34322 of sentences what the service is about. This string allows users to
34323 find about the service through @command{guix system search}
34324 (@pxref{Invoking guix system}).
34326 @item @code{default-value} (default: @code{&no-default-value})
34327 The default value associated for instances of this service type. This
34328 allows users to use the @code{service} form without its second argument:
34331 (service @var{type})
34334 The returned service in this case has the default value specified by
34338 @xref{Service Types and Services}, for examples.
34341 @deffn {Scheme Procedure} service-extension @var{target-type} @
34343 Return a new extension for services of type @var{target-type}.
34344 @var{compute} must be a one-argument procedure: @code{fold-services}
34345 calls it, passing it the value associated with the service that provides
34346 the extension; it must return a valid value for the target service.
34349 @deffn {Scheme Procedure} service-extension? @var{obj}
34350 Return true if @var{obj} is a service extension.
34353 Occasionally, you might want to simply extend an existing service. This
34354 involves creating a new service type and specifying the extension of
34355 interest, which can be verbose; the @code{simple-service} procedure
34356 provides a shorthand for this.
34358 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
34359 Return a service that extends @var{target} with @var{value}. This works
34360 by creating a singleton service type @var{name}, of which the returned
34361 service is an instance.
34363 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
34367 (simple-service 'my-mcron-job mcron-service-type
34368 #~(job '(next-hour (3)) "guix gc -F 2G"))
34372 At the core of the service abstraction lies the @code{fold-services}
34373 procedure, which is responsible for ``compiling'' a list of services
34374 down to a single directory that contains everything needed to boot and
34375 run the system---the directory shown by the @command{guix system build}
34376 command (@pxref{Invoking guix system}). In essence, it propagates
34377 service extensions down the service graph, updating each node parameters
34378 on the way, until it reaches the root node.
34380 @deffn {Scheme Procedure} fold-services @var{services} @
34381 [#:target-type @var{system-service-type}]
34382 Fold @var{services} by propagating their extensions down to the root of
34383 type @var{target-type}; return the root service adjusted accordingly.
34386 Lastly, the @code{(gnu services)} module also defines several essential
34387 service types, some of which are listed below.
34389 @defvr {Scheme Variable} system-service-type
34390 This is the root of the service graph. It produces the system directory
34391 as returned by the @command{guix system build} command.
34394 @defvr {Scheme Variable} boot-service-type
34395 The type of the ``boot service'', which produces the @dfn{boot script}.
34396 The boot script is what the initial RAM disk runs when booting.
34399 @defvr {Scheme Variable} etc-service-type
34400 The type of the @file{/etc} service. This service is used to create
34401 files under @file{/etc} and can be extended by
34402 passing it name/file tuples such as:
34405 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
34408 In this example, the effect would be to add an @file{/etc/issue} file
34409 pointing to the given file.
34412 @defvr {Scheme Variable} setuid-program-service-type
34413 Type for the ``setuid-program service''. This service collects lists of
34414 executable file names, passed as gexps, and adds them to the set of
34415 setuid-root programs on the system (@pxref{Setuid Programs}).
34418 @defvr {Scheme Variable} profile-service-type
34419 Type of the service that populates the @dfn{system profile}---i.e., the
34420 programs under @file{/run/current-system/profile}. Other services can
34421 extend it by passing it lists of packages to add to the system profile.
34424 @cindex provenance tracking, of the operating system
34425 @anchor{provenance-service-type}
34426 @defvr {Scheme Variable} provenance-service-type
34427 This is the type of the service that records @dfn{provenance meta-data}
34428 in the system itself. It creates several files under
34429 @file{/run/current-system}:
34433 This is a ``channel file'' that can be passed to @command{guix pull -C}
34434 or @command{guix time-machine -C}, and which describes the channels used
34435 to build the system, if that information was available
34436 (@pxref{Channels}).
34438 @item configuration.scm
34439 This is the file that was passed as the value for this
34440 @code{provenance-service-type} service. By default, @command{guix
34441 system reconfigure} automatically passes the OS configuration file it
34442 received on the command line.
34445 This contains the same information as the two other files but in a
34446 format that is more readily processable.
34449 In general, these two pieces of information (channels and configuration
34450 file) are enough to reproduce the operating system ``from source''.
34453 This information is necessary to rebuild your operating system, but it
34454 is not always sufficient. In particular, @file{configuration.scm}
34455 itself is insufficient if it is not self-contained---if it refers to
34456 external Guile modules or to extra files. If you want
34457 @file{configuration.scm} to be self-contained, we recommend that modules
34458 or files it refers to be part of a channel.
34460 Besides, provenance meta-data is ``silent'' in the sense that it does
34461 not change the bits contained in your system, @emph{except for the
34462 meta-data bits themselves}. Two different OS configurations or sets of
34463 channels can lead to the same system, bit-for-bit; when
34464 @code{provenance-service-type} is used, these two systems will have
34465 different meta-data and thus different store file names, which makes
34466 comparison less trivial.
34469 This service is automatically added to your operating system
34470 configuration when you use @command{guix system reconfigure},
34471 @command{guix system init}, or @command{guix deploy}.
34474 @defvr {Scheme Variable} linux-loadable-module-service-type
34475 Type of the service that collects lists of packages containing
34476 kernel-loadable modules, and adds them to the set of kernel-loadable
34479 This service type is intended to be extended by other service types,
34483 (simple-service 'installing-module
34484 linux-loadable-module-service-type
34485 (list module-to-install-1
34486 module-to-install-2))
34489 This does not actually load modules at bootup, only adds it to the
34490 kernel profile so that it @emph{can} be loaded by other means.
34493 @node Shepherd Services
34494 @subsection Shepherd Services
34496 @cindex shepherd services
34498 @cindex init system
34499 The @code{(gnu services shepherd)} module provides a way to define
34500 services managed by the GNU@tie{}Shepherd, which is the
34501 initialization system---the first process that is started when the
34502 system boots, also known as PID@tie{}1
34503 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
34505 Services in the Shepherd can depend on each other. For instance, the
34506 SSH daemon may need to be started after the syslog daemon has been
34507 started, which in turn can only happen once all the file systems have
34508 been mounted. The simple operating system defined earlier (@pxref{Using
34509 the Configuration System}) results in a service graph like this:
34511 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
34513 You can actually generate such a graph for any operating system
34514 definition using the @command{guix system shepherd-graph} command
34515 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
34517 The @code{%shepherd-root-service} is a service object representing
34518 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
34519 by passing it lists of @code{<shepherd-service>} objects.
34521 @deftp {Data Type} shepherd-service
34522 The data type representing a service managed by the Shepherd.
34525 @item @code{provision}
34526 This is a list of symbols denoting what the service provides.
34528 These are the names that may be passed to @command{herd start},
34529 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
34530 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
34531 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
34533 @item @code{requirement} (default: @code{'()})
34534 List of symbols denoting the Shepherd services this one depends on.
34536 @cindex one-shot services, for the Shepherd
34537 @item @code{one-shot?} (default: @code{#f})
34538 Whether this service is @dfn{one-shot}. One-shot services stop immediately
34539 after their @code{start} action has completed. @xref{Slots of services,,,
34540 shepherd, The GNU Shepherd Manual}, for more info.
34542 @item @code{respawn?} (default: @code{#t})
34543 Whether to restart the service when it stops, for instance when the
34544 underlying process dies.
34547 @itemx @code{stop} (default: @code{#~(const #f)})
34548 The @code{start} and @code{stop} fields refer to the Shepherd's
34549 facilities to start and stop processes (@pxref{Service De- and
34550 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
34551 G-expressions that get expanded in the Shepherd configuration file
34552 (@pxref{G-Expressions}).
34554 @item @code{actions} (default: @code{'()})
34555 @cindex actions, of Shepherd services
34556 This is a list of @code{shepherd-action} objects (see below) defining
34557 @dfn{actions} supported by the service, in addition to the standard
34558 @code{start} and @code{stop} actions. Actions listed here become available as
34559 @command{herd} sub-commands:
34562 herd @var{action} @var{service} [@var{arguments}@dots{}]
34565 @item @code{auto-start?} (default: @code{#t})
34566 Whether this service should be started automatically by the Shepherd. If it
34567 is @code{#f} the service has to be started manually with @code{herd start}.
34569 @item @code{documentation}
34570 A documentation string, as shown when running:
34573 herd doc @var{service-name}
34576 where @var{service-name} is one of the symbols in @code{provision}
34577 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
34579 @item @code{modules} (default: @code{%default-modules})
34580 This is the list of modules that must be in scope when @code{start} and
34581 @code{stop} are evaluated.
34586 The example below defines a Shepherd service that spawns
34587 @command{syslogd}, the system logger from the GNU Networking Utilities
34588 (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
34592 (let ((config (plain-file "syslogd.conf" "@dots{}")))
34594 (documentation "Run the syslog daemon (syslogd).")
34595 (provision '(syslogd))
34596 (requirement '(user-processes))
34597 (start #~(make-forkexec-constructor
34598 (list #$(file-append inetutils "/libexec/syslogd")
34599 "--rcfile" #$config)
34600 #:pid-file "/var/run/syslog.pid"))
34601 (stop #~(make-kill-destructor))))
34604 Key elements in this example are the @code{start} and @code{stop}
34605 fields: they are @dfn{staged} code snippets that use the
34606 @code{make-forkexec-constructor} procedure provided by the Shepherd and
34607 its dual, @code{make-kill-destructor} (@pxref{Service De- and
34608 Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
34609 field will have @command{shepherd} spawn @command{syslogd} with the
34610 given option; note that we pass @code{config} after @option{--rcfile},
34611 which is a configuration file declared above (contents of this file are
34612 omitted). Likewise, the @code{stop} field tells how this service is to
34613 be stopped; in this case, it is stopped by making the @code{kill} system
34614 call on its PID@. Code staging is achieved using G-expressions:
34615 @code{#~} stages code, while @code{#$} ``escapes'' back to host code
34616 (@pxref{G-Expressions}).
34618 @deftp {Data Type} shepherd-action
34619 This is the data type that defines additional actions implemented by a
34620 Shepherd service (see above).
34624 Symbol naming the action.
34626 @item documentation
34627 This is a documentation string for the action. It can be viewed by running:
34630 herd doc @var{service} action @var{action}
34634 This should be a gexp that evaluates to a procedure of at least one argument,
34635 which is the ``running value'' of the service (@pxref{Slots of services,,,
34636 shepherd, The GNU Shepherd Manual}).
34639 The following example defines an action called @code{say-hello} that kindly
34645 (documentation "Say hi!")
34646 (procedure #~(lambda (running . args)
34647 (format #t "Hello, friend! arguments: ~s\n"
34652 Assuming this action is added to the @code{example} service, then you can do:
34655 # herd say-hello example
34656 Hello, friend! arguments: ()
34657 # herd say-hello example a b c
34658 Hello, friend! arguments: ("a" "b" "c")
34661 This, as you can see, is a fairly sophisticated way to say hello.
34662 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
34666 @defvr {Scheme Variable} shepherd-root-service-type
34667 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
34669 This is the service type that extensions target when they want to create
34670 shepherd services (@pxref{Service Types and Services}, for an example).
34671 Each extension must pass a list of @code{<shepherd-service>}. Its
34672 value must be a @code{shepherd-configuration}, as described below.
34675 @deftp {Data Type} shepherd-configuration
34676 This data type represents the Shepherd's configuration.
34679 @item shepherd (default: @code{shepherd})
34680 The Shepherd package to use.
34682 @item services (default: @code{'()})
34683 A list of @code{<shepherd-service>} to start.
34684 You should probably use the service extension
34685 mechanism instead (@pxref{Shepherd Services}).
34689 The following example specifies the Shepherd package for the operating
34695 (services (append (list openssh-service-type))
34699 ;; Use own Shepherd package.
34700 (essential-services
34701 (modify-services (operating-system-default-essential-services
34702 this-operating-system)
34703 (shepherd-root-service-type config => (shepherd-configuration
34705 (shepherd my-shepherd))))))
34708 @defvr {Scheme Variable} %shepherd-root-service
34709 This service represents PID@tie{}1.
34713 @node Documentation
34714 @chapter Documentation
34716 @cindex documentation, searching for
34717 @cindex searching for documentation
34718 @cindex Info, documentation format
34720 @cindex manual pages
34721 In most cases packages installed with Guix come with documentation.
34722 There are two main documentation formats: ``Info'', a browsable
34723 hypertext format used for GNU software, and ``manual pages'' (or ``man
34724 pages''), the linear documentation format traditionally found on Unix.
34725 Info manuals are accessed with the @command{info} command or with Emacs,
34726 and man pages are accessed using @command{man}.
34728 You can look for documentation of software installed on your system by
34729 keyword. For example, the following command searches for information
34730 about ``TLS'' in Info manuals:
34734 "(emacs)Network Security" -- STARTTLS
34735 "(emacs)Network Security" -- TLS
34736 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
34737 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
34742 The command below searches for the same keyword in man pages:
34746 SSL (7) - OpenSSL SSL/TLS library
34747 certtool (1) - GnuTLS certificate tool
34751 These searches are purely local to your computer so you have the
34752 guarantee that documentation you find corresponds to what you have
34753 actually installed, you can access it off-line, and your privacy is
34756 Once you have these results, you can view the relevant documentation by
34760 $ info "(gnutls)Core TLS API"
34770 Info manuals contain sections and indices as well as hyperlinks like
34771 those found in Web pages. The @command{info} reader (@pxref{Top, Info
34772 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
34773 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
34774 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
34775 Introduction}, for an introduction to Info navigation.
34777 @node Installing Debugging Files
34778 @chapter Installing Debugging Files
34780 @cindex debugging files
34781 Program binaries, as produced by the GCC compilers for instance, are
34782 typically written in the ELF format, with a section containing
34783 @dfn{debugging information}. Debugging information is what allows the
34784 debugger, GDB, to map binary code to source code; it is required to
34785 debug a compiled program in good conditions.
34787 This chapter explains how to use separate debug info when packages
34788 provide it, and how to rebuild packages with debug info when it's
34792 * Separate Debug Info:: Installing 'debug' outputs.
34793 * Rebuilding Debug Info:: Building missing debug info.
34796 @node Separate Debug Info
34797 @section Separate Debug Info
34799 The problem with debugging information is that is takes up a fair amount
34800 of disk space. For example, debugging information for the GNU C Library
34801 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
34802 debugging info of all the installed programs is usually not an option.
34803 Yet, space savings should not come at the cost of an impediment to
34804 debugging---especially in the GNU system, which should make it easier
34805 for users to exert their computing freedom (@pxref{GNU Distribution}).
34807 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
34808 mechanism that allows users to get the best of both worlds: debugging
34809 information can be stripped from the binaries and stored in separate
34810 files. GDB is then able to load debugging information from those files,
34811 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
34814 The GNU distribution takes advantage of this by storing debugging
34815 information in the @code{lib/debug} sub-directory of a separate package
34816 output unimaginatively called @code{debug} (@pxref{Packages with
34817 Multiple Outputs}). Users can choose to install the @code{debug} output
34818 of a package when they need it. For instance, the following command
34819 installs the debugging information for the GNU C Library and for GNU
34823 guix install glibc:debug guile:debug
34826 GDB must then be told to look for debug files in the user's profile, by
34827 setting the @code{debug-file-directory} variable (consider setting it
34828 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
34832 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
34835 From there on, GDB will pick up debugging information from the
34836 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
34838 In addition, you will most likely want GDB to be able to show the source
34839 code being debugged. To do that, you will have to unpack the source
34840 code of the package of interest (obtained with @code{guix build
34841 --source}, @pxref{Invoking guix build}), and to point GDB to that source
34842 directory using the @code{directory} command (@pxref{Source Path,
34843 @code{directory},, gdb, Debugging with GDB}).
34845 @c XXX: keep me up-to-date
34846 The @code{debug} output mechanism in Guix is implemented by the
34847 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
34848 opt-in---debugging information is available only for the packages with
34849 definitions explicitly declaring a @code{debug} output. To check
34850 whether a package has a @code{debug} output, use @command{guix package
34851 --list-available} (@pxref{Invoking guix package}).
34853 Read on for how to deal with packages lacking a @code{debug} output.
34855 @node Rebuilding Debug Info
34856 @section Rebuilding Debug Info
34858 @cindex debugging info, rebuilding
34859 As we saw above, some packages, but not all, provide debugging info in a
34860 @code{debug} output. What can you do when debugging info is missing?
34861 The @option{--with-debug-info} option provides a solution to that: it
34862 allows you to rebuild the package(s) for which debugging info is
34863 missing---and only those---and to graft those onto the application
34864 you're debugging. Thus, while it's not as fast as installing a
34865 @code{debug} output, it is relatively inexpensive.
34867 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
34868 and would like to see what's going on in GLib, a library that's deep
34869 down in its dependency graph. As it turns out, GLib does not have a
34870 @code{debug} output and the backtrace GDB shows is all sadness:
34874 #0 0x00007ffff5f92190 in g_getenv ()
34875 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
34876 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
34877 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
34878 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
34879 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
34880 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
34884 To address that, you install Inkscape linked against a variant GLib that
34885 contains debug info:
34888 guix install inkscape --with-debug-info=glib
34891 This time, debugging will be a whole lot nicer:
34894 $ gdb --args sh -c 'exec inkscape'
34897 Function "g_getenv" not defined.
34898 Make breakpoint pending on future shared library load? (y or [n]) y
34899 Breakpoint 1 (g_getenv) pending.
34901 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
34904 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
34905 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
34906 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
34907 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
34908 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
34914 Note that there can be packages for which @option{--with-debug-info}
34915 will not have the desired effect. @xref{Package Transformation Options,
34916 @option{--with-debug-info}}, for more information.
34918 @node Security Updates
34919 @chapter Security Updates
34921 @cindex security updates
34922 @cindex security vulnerabilities
34923 Occasionally, important security vulnerabilities are discovered in software
34924 packages and must be patched. Guix developers try hard to keep track of
34925 known vulnerabilities and to apply fixes as soon as possible in the
34926 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
34927 containing only security updates). The @command{guix lint} tool helps
34928 developers find out about vulnerable versions of software packages in the
34933 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
34934 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
34935 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
34939 @xref{Invoking guix lint}, for more information.
34941 Guix follows a functional
34942 package management discipline (@pxref{Introduction}), which implies
34943 that, when a package is changed, @emph{every package that depends on it}
34944 must be rebuilt. This can significantly slow down the deployment of
34945 fixes in core packages such as libc or Bash, since basically the whole
34946 distribution would need to be rebuilt. Using pre-built binaries helps
34947 (@pxref{Substitutes}), but deployment may still take more time than
34951 To address this, Guix implements @dfn{grafts}, a mechanism that allows
34952 for fast deployment of critical updates without the costs associated
34953 with a whole-distribution rebuild. The idea is to rebuild only the
34954 package that needs to be patched, and then to ``graft'' it onto packages
34955 explicitly installed by the user and that were previously referring to
34956 the original package. The cost of grafting is typically very low, and
34957 order of magnitudes lower than a full rebuild of the dependency chain.
34959 @cindex replacements of packages, for grafts
34960 For instance, suppose a security update needs to be applied to Bash.
34961 Guix developers will provide a package definition for the ``fixed''
34962 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
34963 Packages}). Then, the original package definition is augmented with a
34964 @code{replacement} field pointing to the package containing the bug fix:
34971 (replacement bash-fixed)))
34974 From there on, any package depending directly or indirectly on Bash---as
34975 reported by @command{guix gc --requisites} (@pxref{Invoking guix
34976 gc})---that is installed is automatically ``rewritten'' to refer to
34977 @code{bash-fixed} instead of @code{bash}. This grafting process takes
34978 time proportional to the size of the package, usually less than a
34979 minute for an ``average'' package on a recent machine. Grafting is
34980 recursive: when an indirect dependency requires grafting, then grafting
34981 ``propagates'' up to the package that the user is installing.
34983 Currently, the length of the name and version of the graft and that of
34984 the package it replaces (@code{bash-fixed} and @code{bash} in the example
34985 above) must be equal. This restriction mostly comes from the fact that
34986 grafting works by patching files, including binary files, directly.
34987 Other restrictions may apply: for instance, when adding a graft to a
34988 package providing a shared library, the original shared library and its
34989 replacement must have the same @code{SONAME} and be binary-compatible.
34991 The @option{--no-grafts} command-line option allows you to forcefully
34992 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
34996 guix build bash --no-grafts
35000 returns the store file name of the original Bash, whereas:
35007 returns the store file name of the ``fixed'', replacement Bash. This
35008 allows you to distinguish between the two variants of Bash.
35010 To verify which Bash your whole profile refers to, you can run
35011 (@pxref{Invoking guix gc}):
35014 guix gc -R $(readlink -f ~/.guix-profile) | grep bash
35018 @dots{} and compare the store file names that you get with those above.
35019 Likewise for a complete Guix system generation:
35022 guix gc -R $(guix system build my-config.scm) | grep bash
35025 Lastly, to check which Bash running processes are using, you can use the
35026 @command{lsof} command:
35029 lsof | grep /gnu/store/.*bash
35033 @node Bootstrapping
35034 @chapter Bootstrapping
35036 @c Adapted from the ELS 2013 paper.
35038 @cindex bootstrapping
35040 Bootstrapping in our context refers to how the distribution gets built
35041 ``from nothing''. Remember that the build environment of a derivation
35042 contains nothing but its declared inputs (@pxref{Introduction}). So
35043 there's an obvious chicken-and-egg problem: how does the first package
35044 get built? How does the first compiler get compiled?
35046 It is tempting to think of this question as one that only die-hard
35047 hackers may care about. However, while the answer to that question is
35048 technical in nature, its implications are wide-ranging. How the
35049 distribution is bootstrapped defines the extent to which we, as
35050 individuals and as a collective of users and hackers, can trust the
35051 software we run. It is a central concern from the standpoint of
35052 @emph{security} and from a @emph{user freedom} viewpoint.
35054 @cindex bootstrap binaries
35055 The GNU system is primarily made of C code, with libc at its core. The
35056 GNU build system itself assumes the availability of a Bourne shell and
35057 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
35058 `grep'. Furthermore, build programs---programs that run
35059 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
35060 (@pxref{Derivations}). Consequently, to be able to build anything at
35061 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
35062 Binutils, libc, and the other packages mentioned above---the
35063 @dfn{bootstrap binaries}.
35065 These bootstrap binaries are ``taken for granted'', though we can also
35066 re-create them if needed (@pxref{Preparing to Use the Bootstrap
35070 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
35071 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
35074 @node Reduced Binary Seed Bootstrap
35075 @section The Reduced Binary Seed Bootstrap
35077 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
35078 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
35079 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
35080 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
35081 ``taken for granted.''
35083 Taking the bootstrap binaries for granted means that we consider them to
35084 be a correct and trustworthy ``seed'' for building the complete system.
35085 Therein lies a problem: the combined size of these bootstrap binaries is
35086 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
35087 or even inspecting these is next to impossible.
35089 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
35090 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
35091 Source Bootstrap'' and while we are working towards that goal it would
35092 be hyperbole to use that term for what we do now.}.
35094 The Reduced Binary Seed bootstrap removes the most critical tools---from a
35095 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
35096 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
35097 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
35098 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
35100 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
35101 C Library are built from source. From here on the more traditional
35102 bootstrap process resumes. This approach has reduced the bootstrap
35103 binaries in size to about 145MB in Guix v1.1.
35105 The next step that Guix has taken is to replace the shell and all its
35106 utilities with implementations in Guile Scheme, the @emph{Scheme-only
35107 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
35108 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
35109 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
35110 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
35111 removed are now built from source.
35113 Building the GNU System from source is currently only possible by adding
35114 some historical GNU packages as intermediate steps@footnote{Packages
35115 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
35116 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
35117 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
35118 and GNU packages become more bootstrappable again (e.g., new releases of
35119 GNU Sed will also ship as gzipped tarballs again, as alternative to the
35120 hard to bootstrap @code{xz}-compression), this set of added packages can
35121 hopefully be reduced again.
35123 The graph below shows the resulting dependency graph for
35124 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
35125 traditional bootstrap of the rest of the Guix System.
35127 @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
35128 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
35130 The only significant binary bootstrap seeds that remain@footnote{
35131 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
35132 together with @code{mes}.} are a Scheme interpreter and a Scheme
35133 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
35134 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
35135 to get Guile running.}.
35137 This further reduction has brought down the size of the binary seed to
35138 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
35140 Work is ongoing to remove all binary blobs from our free software
35141 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
35142 is work to bring these bootstraps to the @code{arm-linux} and
35143 @code{aarch64-linux} architectures and to the Hurd.
35145 If you are interested, join us on @samp{#bootstrappable} on the Freenode
35146 IRC network or discuss on @email{bug-mes@@gnu.org} or
35147 @email{gash-devel@@nongnu.org}.
35149 @node Preparing to Use the Bootstrap Binaries
35150 @section Preparing to Use the Bootstrap Binaries
35152 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
35153 @c large image, it's hard to scroll. Oh well.
35154 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
35156 The figure above shows the very beginning of the dependency graph of the
35157 distribution, corresponding to the package definitions of the @code{(gnu
35158 packages bootstrap)} module. A similar figure can be generated with
35159 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
35162 guix graph -t derivation \
35163 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
35164 | dot -Tps > gcc.ps
35167 or, for the further Reduced Binary Seed bootstrap
35170 guix graph -t derivation \
35171 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
35172 | dot -Tps > mes.ps
35175 At this level of detail, things are
35176 slightly complex. First, Guile itself consists of an ELF executable,
35177 along with many source and compiled Scheme files that are dynamically
35178 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
35179 tarball shown in this graph. This tarball is part of Guix's ``source''
35180 distribution, and gets inserted into the store with @code{add-to-store}
35181 (@pxref{The Store}).
35183 But how do we write a derivation that unpacks this tarball and adds it
35184 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
35185 derivation---the first one that gets built---uses @code{bash} as its
35186 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
35187 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
35188 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
35189 the Guix source distribution, whose sole purpose is to allow the Guile
35190 tarball to be unpacked.
35192 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
35193 Guile that can be used to run subsequent build programs. Its first task
35194 is to download tarballs containing the other pre-built binaries---this
35195 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
35196 @code{ftp-client.scm} are used for this purpose. The
35197 @code{module-import.drv} derivations import those modules in a directory
35198 in the store, using the original layout. The
35199 @code{module-import-compiled.drv} derivations compile those modules, and
35200 write them in an output directory with the right layout. This
35201 corresponds to the @code{#:modules} argument of
35202 @code{build-expression->derivation} (@pxref{Derivations}).
35204 Finally, the various tarballs are unpacked by the derivations
35205 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
35206 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
35207 point we have a working C tool chain.
35209 @unnumberedsec Building the Build Tools
35211 Bootstrapping is complete when we have a full tool chain that does not
35212 depend on the pre-built bootstrap tools discussed above. This
35213 no-dependency requirement is verified by checking whether the files of
35214 the final tool chain contain references to the @file{/gnu/store}
35215 directories of the bootstrap inputs. The process that leads to this
35216 ``final'' tool chain is described by the package definitions found in
35217 the @code{(gnu packages commencement)} module.
35219 The @command{guix graph} command allows us to ``zoom out'' compared to
35220 the graph above, by looking at the level of package objects instead of
35221 individual derivations---remember that a package may translate to
35222 several derivations, typically one derivation to download its source,
35223 one to build the Guile modules it needs, and one to actually build the
35224 package from source. The command:
35227 guix graph -t bag \
35228 -e '(@@@@ (gnu packages commencement)
35229 glibc-final-with-bootstrap-bash)' | xdot -
35233 displays the dependency graph leading to the ``final'' C
35234 library@footnote{You may notice the @code{glibc-intermediate} label,
35235 suggesting that it is not @emph{quite} final, but as a good
35236 approximation, we will consider it final.}, depicted below.
35238 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
35240 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
35241 The first tool that gets built with the bootstrap binaries is
35242 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
35243 for all the following packages. From there Findutils and Diffutils get
35246 Then come the first-stage Binutils and GCC, built as pseudo cross
35247 tools---i.e., with @option{--target} equal to @option{--host}. They are
35248 used to build libc. Thanks to this cross-build trick, this libc is
35249 guaranteed not to hold any reference to the initial tool chain.
35251 From there the final Binutils and GCC (not shown above) are built. GCC
35252 uses @command{ld} from the final Binutils, and links programs against
35253 the just-built libc. This tool chain is used to build the other
35254 packages used by Guix and by the GNU Build System: Guile, Bash,
35257 And voilà! At this point we have the complete set of build tools that
35258 the GNU Build System expects. These are in the @code{%final-inputs}
35259 variable of the @code{(gnu packages commencement)} module, and are
35260 implicitly used by any package that uses @code{gnu-build-system}
35261 (@pxref{Build Systems, @code{gnu-build-system}}).
35264 @unnumberedsec Building the Bootstrap Binaries
35266 @cindex bootstrap binaries
35267 Because the final tool chain does not depend on the bootstrap binaries,
35268 those rarely need to be updated. Nevertheless, it is useful to have an
35269 automated way to produce them, should an update occur, and this is what
35270 the @code{(gnu packages make-bootstrap)} module provides.
35272 The following command builds the tarballs containing the bootstrap binaries
35273 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
35274 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
35275 and Guile, and a tarball containing a mixture of Coreutils and other basic
35276 command-line tools):
35279 guix build bootstrap-tarballs
35282 The generated tarballs are those that should be referred to in the
35283 @code{(gnu packages bootstrap)} module mentioned at the beginning of
35286 Still here? Then perhaps by now you've started to wonder: when do we
35287 reach a fixed point? That is an interesting question! The answer is
35288 unknown, but if you would like to investigate further (and have
35289 significant computational and storage resources to do so), then let us
35292 @unnumberedsec Reducing the Set of Bootstrap Binaries
35294 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
35295 binary code! Why is that a problem? It's a problem because these big chunks
35296 of binary code are practically non-auditable, which makes it hard to establish
35297 what source code produced them. Every unauditable binary also leaves us
35298 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
35299 paper @emph{Reflections on Trusting Trust}.
35301 This is mitigated by the fact that our bootstrap binaries were generated
35302 from an earlier Guix revision. Nevertheless it lacks the level of
35303 transparency that we get in the rest of the package dependency graph,
35304 where Guix always gives us a source-to-binary mapping. Thus, our goal
35305 is to reduce the set of bootstrap binaries to the bare minimum.
35307 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
35308 on-going projects to do that. One of these is about replacing the
35309 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
35310 of increasing complexity, which could be built from source starting from
35311 a simple and auditable assembler.
35313 Our first major achievement is the replacement of of GCC, the GNU C Library
35314 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
35315 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
35316 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
35317 bootstrapped yet and thus we inject them as binary seeds. We call this the
35318 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
35319 binaries! Also, it has eliminated the C compiler binary; i686-linux and
35320 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
35322 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
35323 also looking at any other bootstrap binaries. Your help is welcome!
35326 @chapter Porting to a New Platform
35328 As discussed above, the GNU distribution is self-contained, and
35329 self-containment is achieved by relying on pre-built ``bootstrap
35330 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
35331 operating system kernel, CPU architecture, and application binary
35332 interface (ABI). Thus, to port the distribution to a platform that is
35333 not yet supported, one must build those bootstrap binaries, and update
35334 the @code{(gnu packages bootstrap)} module to use them on that platform.
35336 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
35337 When everything goes well, and assuming the GNU tool chain supports the
35338 target platform, this can be as simple as running a command like this
35342 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
35345 For this to work, the @code{glibc-dynamic-linker} procedure in
35346 @code{(gnu packages bootstrap)} must be augmented to return the right
35347 file name for libc's dynamic linker on that platform; likewise,
35348 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
35349 taught about the new platform.
35351 Once these are built, the @code{(gnu packages bootstrap)} module needs
35352 to be updated to refer to these binaries on the target platform. That
35353 is, the hashes and URLs of the bootstrap tarballs for the new platform
35354 must be added alongside those of the currently supported platforms. The
35355 bootstrap Guile tarball is treated specially: it is expected to be
35356 available locally, and @file{gnu/local.mk} has rules to download it for
35357 the supported architectures; a rule for the new platform must be added
35360 In practice, there may be some complications. First, it may be that the
35361 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
35362 above) is not recognized by all the GNU tools. Typically, glibc
35363 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
35364 configure flag (see @code{gcc.scm} for examples of how to handle this).
35365 Second, some of the required packages could fail to build for that
35366 platform. Lastly, the generated binaries could be broken for some
35369 @c *********************************************************************
35370 @include contributing.texi
35372 @c *********************************************************************
35373 @node Acknowledgments
35374 @chapter Acknowledgments
35376 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
35377 which was designed and
35378 implemented by Eelco Dolstra, with contributions from other people (see
35379 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
35380 management, and promoted unprecedented features, such as transactional
35381 package upgrades and rollbacks, per-user profiles, and referentially
35382 transparent build processes. Without this work, Guix would not exist.
35384 The Nix-based software distributions, Nixpkgs and NixOS, have also been
35385 an inspiration for Guix.
35387 GNU@tie{}Guix itself is a collective work with contributions from a
35388 number of people. See the @file{AUTHORS} file in Guix for more
35389 information on these fine people. The @file{THANKS} file lists people
35390 who have helped by reporting bugs, taking care of the infrastructure,
35391 providing artwork and themes, making suggestions, and more---thank you!
35394 @c *********************************************************************
35395 @node GNU Free Documentation License
35396 @appendix GNU Free Documentation License
35397 @cindex license, GNU Free Documentation License
35398 @include fdl-1.3.texi
35400 @c *********************************************************************
35401 @node Concept Index
35402 @unnumbered Concept Index
35405 @node Programming Index
35406 @unnumbered Programming Index
35407 @syncodeindex tp fn
35408 @syncodeindex vr fn
35413 @c Local Variables:
35414 @c ispell-local-dictionary: "american";