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 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
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 ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017, 2019 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019 Guillaume Le Vaillant@*
73 Permission is granted to copy, distribute and/or modify this document
74 under the terms of the GNU Free Documentation License, Version 1.3 or
75 any later version published by the Free Software Foundation; with no
76 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
77 copy of the license is included in the section entitled ``GNU Free
78 Documentation License''.
81 @dircategory System administration
83 * Guix: (guix). Manage installed software and system configuration.
84 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
85 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
86 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
87 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
88 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
91 @dircategory Software development
93 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
94 * guix build: (guix)Invoking guix build. Building packages.
95 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
99 @title GNU Guix Reference Manual
100 @subtitle Using the GNU Guix Functional Package Manager
101 @author The GNU Guix Developers
104 @vskip 0pt plus 1filll
105 Edition @value{EDITION} @*
113 @c *********************************************************************
117 This document describes GNU Guix version @value{VERSION}, a functional
118 package management tool written for the GNU system.
120 @c TRANSLATORS: You can replace the following paragraph with information on
121 @c how to join your own translation team and how to report issues with the
123 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
124 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
125 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
126 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
127 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
128 would like to translate it in your native language, consider joining the
129 @uref{https://translationproject.org/domain/guix-manual.html, Translation
133 * Introduction:: What is Guix about?
134 * Installation:: Installing Guix.
135 * System Installation:: Installing the whole operating system.
136 * Package Management:: Package installation, upgrade, etc.
137 * Development:: Guix-aided software development.
138 * Programming Interface:: Using Guix in Scheme.
139 * Utilities:: Package management commands.
140 * System Configuration:: Configuring the operating system.
141 * Documentation:: Browsing software user manuals.
142 * Installing Debugging Files:: Feeding the debugger.
143 * Security Updates:: Deploying security fixes quickly.
144 * Bootstrapping:: GNU/Linux built from scratch.
145 * Porting:: Targeting another platform or kernel.
146 * Contributing:: Your help needed!
148 * Acknowledgments:: Thanks!
149 * GNU Free Documentation License:: The license of this manual.
150 * Concept Index:: Concepts.
151 * Programming Index:: Data types, functions, and variables.
154 --- The Detailed Node Listing ---
158 * Managing Software the Guix Way:: What's special.
159 * GNU Distribution:: The packages and tools.
163 * Binary Installation:: Getting Guix running in no time!
164 * Requirements:: Software needed to build and run Guix.
165 * Running the Test Suite:: Testing Guix.
166 * Setting Up the Daemon:: Preparing the build daemon's environment.
167 * Invoking guix-daemon:: Running the build daemon.
168 * Application Setup:: Application-specific setup.
170 Setting Up the Daemon
172 * Build Environment Setup:: Preparing the isolated build environment.
173 * Daemon Offload Setup:: Offloading builds to remote machines.
174 * SELinux Support:: Using an SELinux policy for the daemon.
178 * Limitations:: What you can expect.
179 * Hardware Considerations:: Supported hardware.
180 * USB Stick and DVD Installation:: Preparing the installation medium.
181 * Preparing for Installation:: Networking, partitioning, etc.
182 * Guided Graphical Installation:: Easy graphical installation.
183 * Manual Installation:: Manual installation for wizards.
184 * After System Installation:: When installation succeeded.
185 * Installing Guix in a VM:: Guix System playground.
186 * Building the Installation Image:: How this comes to be.
190 * Keyboard Layout and Networking and Partitioning:: Initial setup.
191 * Proceeding with the Installation:: Installing.
195 * Features:: How Guix will make your life brighter.
196 * Invoking guix package:: Package installation, removal, etc.
197 * Substitutes:: Downloading pre-built binaries.
198 * Packages with Multiple Outputs:: Single source package, multiple outputs.
199 * Invoking guix gc:: Running the garbage collector.
200 * Invoking guix pull:: Fetching the latest Guix and distribution.
201 * Channels:: Customizing the package collection.
202 * Invoking guix time-machine:: Running an older revision of Guix.
203 * Inferiors:: Interacting with another revision of Guix.
204 * Invoking guix describe:: Display information about your Guix revision.
205 * Invoking guix archive:: Exporting and importing store files.
209 * Official Substitute Server:: One particular source of substitutes.
210 * Substitute Server Authorization:: How to enable or disable substitutes.
211 * Substitute Authentication:: How Guix verifies substitutes.
212 * Proxy Settings:: How to get substitutes via proxy.
213 * Substitution Failure:: What happens when substitution fails.
214 * On Trusting Binaries:: How can you trust that binary blob?
218 * Invoking guix environment:: Setting up development environments.
219 * Invoking guix pack:: Creating software bundles.
221 Programming Interface
223 * Package Modules:: Packages from the programmer's viewpoint.
224 * Defining Packages:: Defining new packages.
225 * Build Systems:: Specifying how packages are built.
226 * The Store:: Manipulating the package store.
227 * Derivations:: Low-level interface to package derivations.
228 * The Store Monad:: Purely functional interface to the store.
229 * G-Expressions:: Manipulating build expressions.
230 * Invoking guix repl:: Fiddling with Guix interactively.
234 * package Reference:: The package data type.
235 * origin Reference:: The origin data type.
239 * Invoking guix build:: Building packages from the command line.
240 * Invoking guix edit:: Editing package definitions.
241 * Invoking guix download:: Downloading a file and printing its hash.
242 * Invoking guix hash:: Computing the cryptographic hash of a file.
243 * Invoking guix import:: Importing package definitions.
244 * Invoking guix refresh:: Updating package definitions.
245 * Invoking guix lint:: Finding errors in package definitions.
246 * Invoking guix size:: Profiling disk usage.
247 * Invoking guix graph:: Visualizing the graph of packages.
248 * Invoking guix publish:: Sharing substitutes.
249 * Invoking guix challenge:: Challenging substitute servers.
250 * Invoking guix copy:: Copying to and from a remote store.
251 * Invoking guix container:: Process isolation.
252 * Invoking guix weather:: Assessing substitute availability.
253 * Invoking guix processes:: Listing client processes.
255 Invoking @command{guix build}
257 * Common Build Options:: Build options for most commands.
258 * Package Transformation Options:: Creating variants of packages.
259 * Additional Build Options:: Options specific to 'guix build'.
260 * Debugging Build Failures:: Real life packaging experience.
264 * Using the Configuration System:: Customizing your GNU system.
265 * operating-system Reference:: Detail of operating-system declarations.
266 * File Systems:: Configuring file system mounts.
267 * Mapped Devices:: Block device extra processing.
268 * User Accounts:: Specifying user accounts.
269 * Keyboard Layout:: How the system interprets key strokes.
270 * Locales:: Language and cultural convention settings.
271 * Services:: Specifying system services.
272 * Setuid Programs:: Programs running with root privileges.
273 * X.509 Certificates:: Authenticating HTTPS servers.
274 * Name Service Switch:: Configuring libc's name service switch.
275 * Initial RAM Disk:: Linux-Libre bootstrapping.
276 * Bootloader Configuration:: Configuring the boot loader.
277 * Invoking guix system:: Instantiating a system configuration.
278 * Invoking guix deploy:: Deploying a system configuration to a remote host.
279 * Running Guix in a VM:: How to run Guix System in a virtual machine.
280 * Defining Services:: Adding new service definitions.
284 * Base Services:: Essential system services.
285 * Scheduled Job Execution:: The mcron service.
286 * Log Rotation:: The rottlog service.
287 * Networking Services:: Network setup, SSH daemon, etc.
288 * X Window:: Graphical display.
289 * Printing Services:: Local and remote printer support.
290 * Desktop Services:: D-Bus and desktop services.
291 * Sound Services:: ALSA and Pulseaudio services.
292 * Database Services:: SQL databases, key-value stores, etc.
293 * Mail Services:: IMAP, POP3, SMTP, and all that.
294 * Messaging Services:: Messaging services.
295 * Telephony Services:: Telephony services.
296 * Monitoring Services:: Monitoring services.
297 * Kerberos Services:: Kerberos services.
298 * Web Services:: Web servers.
299 * Certificate Services:: TLS certificates via Let's Encrypt.
300 * DNS Services:: DNS daemons.
301 * VPN Services:: VPN daemons.
302 * Network File System:: NFS related services.
303 * Continuous Integration:: The Cuirass service.
304 * Power Management Services:: Extending battery life.
305 * Audio Services:: The MPD.
306 * Virtualization Services:: Virtualization services.
307 * Version Control Services:: Providing remote access to Git repositories.
308 * Game Services:: Game servers.
309 * PAM Mount Service:: Service to mount volumes when logging in.
310 * Miscellaneous Services:: Other services.
314 * Service Composition:: The model for composing services.
315 * Service Types and Services:: Types and services.
316 * Service Reference:: API reference.
317 * Shepherd Services:: A particular type of service.
322 @c *********************************************************************
324 @chapter Introduction
327 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
328 using the international phonetic alphabet (IPA).} is a package
329 management tool for and distribution of the GNU system.
330 Guix makes it easy for unprivileged
331 users to install, upgrade, or remove software packages, to roll back to a
332 previous package set, to build packages from source, and generally
333 assists with the creation and maintenance of software environments.
336 @cindex GuixSD, now Guix System
337 @cindex Guix System Distribution, now Guix System
338 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
339 complements the available tools without interference (@pxref{Installation}),
340 or you can use it as a standalone operating system distribution,
341 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
342 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
343 group everything under the ``Guix'' banner since, after all, Guix System is
344 readily available through the @command{guix system} command, even if you're
345 using a different distro underneath!}. @xref{GNU Distribution}.
348 * Managing Software the Guix Way:: What's special.
349 * GNU Distribution:: The packages and tools.
352 @node Managing Software the Guix Way
353 @section Managing Software the Guix Way
355 @cindex user interfaces
356 Guix provides a command-line package management interface
357 (@pxref{Package Management}), tools to help with software development
358 (@pxref{Development}), command-line utilities for more advanced usage,
359 (@pxref{Utilities}), as well as Scheme programming interfaces
360 (@pxref{Programming Interface}).
362 Its @dfn{build daemon} is responsible for building packages on behalf of
363 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
364 binaries from authorized sources (@pxref{Substitutes}).
366 @cindex extensibility of the distribution
367 @cindex customization, of packages
368 Guix includes package definitions for many GNU and non-GNU packages, all
369 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
370 user's computing freedom}. It is @emph{extensible}: users can write
371 their own package definitions (@pxref{Defining Packages}) and make them
372 available as independent package modules (@pxref{Package Modules}). It
373 is also @emph{customizable}: users can @emph{derive} specialized package
374 definitions from existing ones, including from the command line
375 (@pxref{Package Transformation Options}).
377 @cindex functional package management
379 Under the hood, Guix implements the @dfn{functional package management}
380 discipline pioneered by Nix (@pxref{Acknowledgments}).
381 In Guix, the package build and installation process is seen
382 as a @emph{function}, in the mathematical sense. That function takes inputs,
383 such as build scripts, a compiler, and libraries, and
384 returns an installed package. As a pure function, its result depends
385 solely on its inputs---for instance, it cannot refer to software or
386 scripts that were not explicitly passed as inputs. A build function
387 always produces the same result when passed a given set of inputs. It
388 cannot alter the environment of the running system in
389 any way; for instance, it cannot create, modify, or delete files outside
390 of its build and installation directories. This is achieved by running
391 build processes in isolated environments (or @dfn{containers}), where only their
392 explicit inputs are visible.
395 The result of package build functions is @dfn{cached} in the file
396 system, in a special directory called @dfn{the store} (@pxref{The
397 Store}). Each package is installed in a directory of its own in the
398 store---by default under @file{/gnu/store}. The directory name contains
399 a hash of all the inputs used to build that package; thus, changing an
400 input yields a different directory name.
402 This approach is the foundation for the salient features of Guix: support
403 for transactional package upgrade and rollback, per-user installation, and
404 garbage collection of packages (@pxref{Features}).
407 @node GNU Distribution
408 @section GNU Distribution
411 Guix comes with a distribution of the GNU system consisting entirely of
412 free software@footnote{The term ``free'' here refers to the
413 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
414 users of that software}.}. The
415 distribution can be installed on its own (@pxref{System Installation}),
416 but it is also possible to install Guix as a package manager on top of
417 an installed GNU/Linux system (@pxref{Installation}). When we need to
418 distinguish between the two, we refer to the standalone distribution as
421 The distribution provides core GNU packages such as GNU libc, GCC, and
422 Binutils, as well as many GNU and non-GNU applications. The complete
423 list of available packages can be browsed
424 @url{https://www.gnu.org/software/guix/packages,on-line} or by
425 running @command{guix package} (@pxref{Invoking guix package}):
428 guix package --list-available
431 Our goal is to provide a practical 100% free software distribution of
432 Linux-based and other variants of GNU, with a focus on the promotion and
433 tight integration of GNU components, and an emphasis on programs and
434 tools that help users exert that freedom.
436 Packages are currently available on the following platforms:
441 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
444 Intel 32-bit architecture (IA32), Linux-Libre kernel;
447 ARMv7-A architecture with hard float, Thumb-2 and NEON,
448 using the EABI hard-float application binary interface (ABI),
449 and Linux-Libre kernel.
452 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
455 little-endian 64-bit MIPS processors, specifically the Loongson series,
456 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
457 supported; in particular, the project's build farms no longer provide
458 substitutes for this architecture.
462 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
463 configuration and Guix takes care of instantiating the configuration in a
464 transactional, reproducible, and stateless fashion (@pxref{System
465 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
466 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
467 Manual}), the well-known GNU utilities and tool chain, as well as the
468 graphical environment or system services of your choice.
470 Guix System is available on all the above platforms except
471 @code{mips64el-linux}.
474 For information on porting to other architectures or kernels,
477 Building this distribution is a cooperative effort, and you are invited
478 to join! @xref{Contributing}, for information about how you can help.
481 @c *********************************************************************
483 @chapter Installation
485 @cindex installing Guix
488 We recommend the use of this
489 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
490 shell installer script} to install Guix on top of a running GNU/Linux system,
491 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
492 with the installation of the package manager, which can be done on top of a
493 running GNU/Linux system. If, instead, you want to install the complete GNU
494 operating system, @pxref{System Installation}.} The script automates the
495 download, installation, and initial configuration of Guix. It should be run
499 @cindex foreign distro
500 @cindex directories related to foreign distro
501 When installed on a foreign distro, GNU@tie{}Guix complements the available
502 tools without interference. Its data lives exclusively in two directories,
503 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
504 such as @file{/etc}, are left untouched.
506 Once installed, Guix can be updated by running @command{guix pull}
507 (@pxref{Invoking guix pull}).
509 If you prefer to perform the installation steps manually or want to tweak
510 them, you may find the following subsections useful. They describe the
511 software requirements of Guix, as well as how to install it manually and get
515 * Binary Installation:: Getting Guix running in no time!
516 * Requirements:: Software needed to build and run Guix.
517 * Running the Test Suite:: Testing Guix.
518 * Setting Up the Daemon:: Preparing the build daemon's environment.
519 * Invoking guix-daemon:: Running the build daemon.
520 * Application Setup:: Application-specific setup.
521 * Upgrading Guix:: Upgrading Guix and its build daemon.
524 @node Binary Installation
525 @section Binary Installation
527 @cindex installing Guix from binaries
528 @cindex installer script
529 This section describes how to install Guix on an arbitrary system from a
530 self-contained tarball providing binaries for Guix and for all its
531 dependencies. This is often quicker than installing from source, which
532 is described in the next sections. The only requirement is to have
535 @c Note duplicated from the ``Installation'' node.
537 We recommend the use of this
538 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
539 shell installer script}. The script automates the download, installation, and
540 initial configuration steps described below. It should be run as the root
544 Installing goes along these lines:
548 @cindex downloading Guix binary
549 Download the binary tarball from
550 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
551 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
552 already running the kernel Linux, and so on.
554 @c The following is somewhat duplicated in ``System Installation''.
555 Make sure to download the associated @file{.sig} file and to verify the
556 authenticity of the tarball against it, along these lines:
559 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
560 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
563 If that command fails because you do not have the required public key,
564 then run this command to import it:
567 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
568 -qO - | gpg --import -
572 and rerun the @code{gpg --verify} command.
574 Take note that a warning like ``This key is not certified with a trusted
575 signature!'' is normal.
577 @c end authentication part
580 Now, you need to become the @code{root} user. Depending on your distribution,
581 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
585 # tar --warning=no-timestamp -xf \
586 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
587 # mv var/guix /var/ && mv gnu /
590 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
591 The latter contains a ready-to-use profile for @code{root} (see next
594 Do @emph{not} unpack the tarball on a working Guix system since that
595 would overwrite its own essential files.
597 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
598 not emit warnings about ``implausibly old time stamps'' (such
599 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
601 They stem from the fact that all the
602 files in the archive have their modification time set to zero (which
603 means January 1st, 1970.) This is done on purpose to make sure the
604 archive content is independent of its creation time, thus making it
608 Make the profile available under @file{~root/.config/guix/current}, which is
609 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
612 # mkdir -p ~root/.config/guix
613 # ln -sf /var/guix/profiles/per-user/root/current-guix \
614 ~root/.config/guix/current
617 Source @file{etc/profile} to augment @code{PATH} and other relevant
618 environment variables:
621 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
622 source $GUIX_PROFILE/etc/profile
626 Create the group and user accounts for build users as explained below
627 (@pxref{Build Environment Setup}).
630 Run the daemon, and set it to automatically start on boot.
632 If your host distro uses the systemd init system, this can be achieved
635 @c Versions of systemd that supported symlinked service files are not
636 @c yet widely deployed, so we should suggest that users copy the service
639 @c See this thread for more information:
640 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
643 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
645 # systemctl start guix-daemon && systemctl enable guix-daemon
648 If your host distro uses the Upstart init system:
651 # initctl reload-configuration
652 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
657 Otherwise, you can still start the daemon manually with:
660 # ~root/.config/guix/current/bin/guix-daemon \
661 --build-users-group=guixbuild
665 Make the @command{guix} command available to other users on the machine,
669 # mkdir -p /usr/local/bin
671 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
674 It is also a good idea to make the Info version of this manual available
678 # mkdir -p /usr/local/share/info
679 # cd /usr/local/share/info
680 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
684 That way, assuming @file{/usr/local/share/info} is in the search path,
685 running @command{info guix} will open this manual (@pxref{Other Info
686 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
690 @cindex substitutes, authorization thereof
691 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
692 (@pxref{Substitutes}), authorize them:
695 # guix archive --authorize < \
696 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
700 Each user may need to perform a few additional steps to make their Guix
701 environment ready for use, @pxref{Application Setup}.
704 Voilà, the installation is complete!
706 You can confirm that Guix is working by installing a sample package into
713 The binary installation tarball can be (re)produced and verified simply
714 by running the following command in the Guix source tree:
717 make guix-binary.@var{system}.tar.xz
721 ...@: which, in turn, runs:
724 guix pack -s @var{system} --localstatedir \
725 --profile-name=current-guix guix
728 @xref{Invoking guix pack}, for more info on this handy tool.
731 @section Requirements
733 This section lists requirements when building Guix from source. The
734 build procedure for Guix is the same as for other GNU software, and is
735 not covered here. Please see the files @file{README} and @file{INSTALL}
736 in the Guix source tree for additional details.
738 @cindex official website
739 GNU Guix is available for download from its website at
740 @url{https://www.gnu.org/software/guix/}.
742 GNU Guix depends on the following packages:
745 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
746 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
749 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
750 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
751 Guile,, gnutls-guile, GnuTLS-Guile});
753 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
756 @c FIXME: Specify a version number once a release has been made.
757 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
759 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
760 @item @url{https://zlib.net, zlib};
761 @item @url{https://www.gnu.org/software/make/, GNU Make}.
764 The following dependencies are optional:
768 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
769 Support for build offloading (@pxref{Daemon Offload Setup}) and
770 @command{guix copy} (@pxref{Invoking guix copy}) depends on
771 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
772 version 0.10.2 or later.
775 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
776 substitutes can be used and @command{guix publish} can compress substitutes
780 When @url{http://www.bzip.org, libbz2} is available,
781 @command{guix-daemon} can use it to compress build logs.
784 Unless @code{--disable-daemon} was passed to @command{configure}, the
785 following packages are also needed:
788 @item @url{https://gnupg.org/, GNU libgcrypt};
789 @item @url{https://sqlite.org, SQLite 3};
790 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
794 @cindex state directory
795 When configuring Guix on a system that already has a Guix installation,
796 be sure to specify the same state directory as the existing installation
797 using the @code{--localstatedir} option of the @command{configure}
798 script (@pxref{Directory Variables, @code{localstatedir},, standards,
799 GNU Coding Standards}). Usually, this @var{localstatedir} option is
800 set to the value @file{/var}. The @command{configure} script protects
801 against unintended misconfiguration of @var{localstatedir} so you do not
802 inadvertently corrupt your store (@pxref{The Store}).
804 @node Running the Test Suite
805 @section Running the Test Suite
808 After a successful @command{configure} and @code{make} run, it is a good
809 idea to run the test suite. It can help catch issues with the setup or
810 environment, or bugs in Guix itself---and really, reporting test
811 failures is a good way to help improve the software. To run the test
818 Test cases can run in parallel: you can use the @code{-j} option of
819 GNU@tie{}make to speed things up. The first run may take a few minutes
820 on a recent machine; subsequent runs will be faster because the store
821 that is created for test purposes will already have various things in
824 It is also possible to run a subset of the tests by defining the
825 @code{TESTS} makefile variable as in this example:
828 make check TESTS="tests/store.scm tests/cpio.scm"
831 By default, tests results are displayed at a file level. In order to
832 see the details of every individual test cases, it is possible to define
833 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
836 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
839 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
840 @file{test-suite.log} file. Please specify the Guix version being used
841 as well as version numbers of the dependencies (@pxref{Requirements}) in
844 Guix also comes with a whole-system test suite that tests complete
845 Guix System instances. It can only run on systems where
846 Guix is already installed, using:
853 or, again, by defining @code{TESTS} to select a subset of tests to run:
856 make check-system TESTS="basic mcron"
859 These system tests are defined in the @code{(gnu tests @dots{})}
860 modules. They work by running the operating systems under test with
861 lightweight instrumentation in a virtual machine (VM). They can be
862 computationally intensive or rather cheap, depending on whether
863 substitutes are available for their dependencies (@pxref{Substitutes}).
864 Some of them require a lot of storage space to hold VM images.
866 Again in case of test failures, please send @email{bug-guix@@gnu.org}
869 @node Setting Up the Daemon
870 @section Setting Up the Daemon
873 Operations such as building a package or running the garbage collector
874 are all performed by a specialized process, the @dfn{build daemon}, on
875 behalf of clients. Only the daemon may access the store and its
876 associated database. Thus, any operation that manipulates the store
877 goes through the daemon. For instance, command-line tools such as
878 @command{guix package} and @command{guix build} communicate with the
879 daemon (@i{via} remote procedure calls) to instruct it what to do.
881 The following sections explain how to prepare the build daemon's
882 environment. See also @ref{Substitutes}, for information on how to allow
883 the daemon to download pre-built binaries.
886 * Build Environment Setup:: Preparing the isolated build environment.
887 * Daemon Offload Setup:: Offloading builds to remote machines.
888 * SELinux Support:: Using an SELinux policy for the daemon.
891 @node Build Environment Setup
892 @subsection Build Environment Setup
894 @cindex build environment
895 In a standard multi-user setup, Guix and its daemon---the
896 @command{guix-daemon} program---are installed by the system
897 administrator; @file{/gnu/store} is owned by @code{root} and
898 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
899 Guix tools to build packages or otherwise access the store, and the
900 daemon will do it on their behalf, ensuring that the store is kept in a
901 consistent state, and allowing built packages to be shared among users.
904 When @command{guix-daemon} runs as @code{root}, you may not want package
905 build processes themselves to run as @code{root} too, for obvious
906 security reasons. To avoid that, a special pool of @dfn{build users}
907 should be created for use by build processes started by the daemon.
908 These build users need not have a shell and a home directory: they will
909 just be used when the daemon drops @code{root} privileges in build
910 processes. Having several such users allows the daemon to launch
911 distinct build processes under separate UIDs, which guarantees that they
912 do not interfere with each other---an essential feature since builds are
913 regarded as pure functions (@pxref{Introduction}).
915 On a GNU/Linux system, a build user pool may be created like this (using
916 Bash syntax and the @code{shadow} commands):
918 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
919 @c for why `-G' is needed.
921 # groupadd --system guixbuild
922 # for i in `seq -w 1 10`;
924 useradd -g guixbuild -G guixbuild \
925 -d /var/empty -s `which nologin` \
926 -c "Guix build user $i" --system \
932 The number of build users determines how many build jobs may run in
933 parallel, as specified by the @option{--max-jobs} option
934 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
935 @command{guix system vm} and related commands, you may need to add the
936 build users to the @code{kvm} group so they can access @file{/dev/kvm},
937 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
938 (@pxref{Invoking guix system}).
940 The @code{guix-daemon} program may then be run as @code{root} with the
941 following command@footnote{If your machine uses the systemd init system,
942 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
943 file in @file{/etc/systemd/system} will ensure that
944 @command{guix-daemon} is automatically started. Similarly, if your
945 machine uses the Upstart init system, drop the
946 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
947 file in @file{/etc/init}.}:
950 # guix-daemon --build-users-group=guixbuild
955 This way, the daemon starts build processes in a chroot, under one of
956 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
957 environment contains nothing but:
959 @c Keep this list in sync with libstore/build.cc! -----------------------
962 a minimal @code{/dev} directory, created mostly independently from the
963 host @code{/dev}@footnote{``Mostly'', because while the set of files
964 that appear in the chroot's @code{/dev} is fixed, most of these files
965 can only be created if the host has them.};
968 the @code{/proc} directory; it only shows the processes of the container
969 since a separate PID name space is used;
972 @file{/etc/passwd} with an entry for the current user and an entry for
976 @file{/etc/group} with an entry for the user's group;
979 @file{/etc/hosts} with an entry that maps @code{localhost} to
983 a writable @file{/tmp} directory.
986 You can influence the directory where the daemon stores build trees
987 @i{via} the @code{TMPDIR} environment variable. However, the build tree
988 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
989 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
990 This way, the value of @code{TMPDIR} does not leak inside build
991 environments, which avoids discrepancies in cases where build processes
992 capture the name of their build tree.
995 The daemon also honors the @code{http_proxy} environment variable for
996 HTTP downloads it performs, be it for fixed-output derivations
997 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
999 If you are installing Guix as an unprivileged user, it is still possible
1000 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1001 However, build processes will not be isolated from one another, and not
1002 from the rest of the system. Thus, build processes may interfere with
1003 each other, and may access programs, libraries, and other files
1004 available on the system---making it much harder to view them as
1005 @emph{pure} functions.
1008 @node Daemon Offload Setup
1009 @subsection Using the Offload Facility
1013 When desired, the build daemon can @dfn{offload} derivation builds to
1014 other machines running Guix, using the @code{offload} @dfn{build
1015 hook}@footnote{This feature is available only when
1016 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1017 present.}. When that
1018 feature is enabled, a list of user-specified build machines is read from
1019 @file{/etc/guix/machines.scm}; every time a build is requested, for
1020 instance via @code{guix build}, the daemon attempts to offload it to one
1021 of the machines that satisfy the constraints of the derivation, in
1022 particular its system type---e.g., @file{x86_64-linux}. Missing
1023 prerequisites for the build are copied over SSH to the target machine,
1024 which then proceeds with the build; upon success the output(s) of the
1025 build are copied back to the initial machine.
1027 The @file{/etc/guix/machines.scm} file typically looks like this:
1030 (list (build-machine
1031 (name "eightysix.example.org")
1032 (system "x86_64-linux")
1033 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1035 (speed 2.)) ;incredibly fast!
1038 (name "meeps.example.org")
1039 (system "mips64el-linux")
1040 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1043 (string-append (getenv "HOME")
1044 "/.ssh/identity-for-guix"))))
1048 In the example above we specify a list of two build machines, one for
1049 the @code{x86_64} architecture and one for the @code{mips64el}
1052 In fact, this file is---not surprisingly!---a Scheme file that is
1053 evaluated when the @code{offload} hook is started. Its return value
1054 must be a list of @code{build-machine} objects. While this example
1055 shows a fixed list of build machines, one could imagine, say, using
1056 DNS-SD to return a list of potential build machines discovered in the
1057 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1058 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1061 @deftp {Data Type} build-machine
1062 This data type represents build machines to which the daemon may offload
1063 builds. The important fields are:
1068 The host name of the remote machine.
1071 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1074 The user account to use when connecting to the remote machine over SSH.
1075 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1076 allow non-interactive logins.
1079 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1080 This is used to authenticate the machine when we connect to it. It is a
1081 long string that looks like this:
1084 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1087 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1088 key can be found in a file such as
1089 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1091 If the machine is running the SSH daemon of GNU@tie{}lsh,
1092 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1093 similar file. It can be converted to the OpenSSH format using
1094 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1097 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1098 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1103 A number of optional fields may be specified:
1107 @item @code{port} (default: @code{22})
1108 Port number of SSH server on the machine.
1110 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1111 The SSH private key file to use when connecting to the machine, in
1112 OpenSSH format. This key must not be protected with a passphrase.
1114 Note that the default value is the private key @emph{of the root
1115 account}. Make sure it exists if you use the default.
1117 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1118 @itemx @code{compression-level} (default: @code{3})
1119 The SSH-level compression methods and compression level requested.
1121 Note that offloading relies on SSH compression to reduce bandwidth usage
1122 when transferring files to and from build machines.
1124 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1125 File name of the Unix-domain socket @command{guix-daemon} is listening
1128 @item @code{parallel-builds} (default: @code{1})
1129 The number of builds that may run in parallel on the machine.
1131 @item @code{speed} (default: @code{1.0})
1132 A ``relative speed factor''. The offload scheduler will tend to prefer
1133 machines with a higher speed factor.
1135 @item @code{features} (default: @code{'()})
1136 A list of strings denoting specific features supported by the machine.
1137 An example is @code{"kvm"} for machines that have the KVM Linux modules
1138 and corresponding hardware support. Derivations can request features by
1139 name, and they will be scheduled on matching build machines.
1144 The @command{guix} command must be in the search path on the build
1145 machines. You can check whether this is the case by running:
1148 ssh build-machine guix repl --version
1151 There is one last thing to do once @file{machines.scm} is in place. As
1152 explained above, when offloading, files are transferred back and forth
1153 between the machine stores. For this to work, you first need to
1154 generate a key pair on each machine to allow the daemon to export signed
1155 archives of files from the store (@pxref{Invoking guix archive}):
1158 # guix archive --generate-key
1162 Each build machine must authorize the key of the master machine so that
1163 it accepts store items it receives from the master:
1166 # guix archive --authorize < master-public-key.txt
1170 Likewise, the master machine must authorize the key of each build machine.
1172 All the fuss with keys is here to express pairwise mutual trust
1173 relations between the master and the build machines. Concretely, when
1174 the master receives files from a build machine (and @i{vice versa}), its
1175 build daemon can make sure they are genuine, have not been tampered
1176 with, and that they are signed by an authorized key.
1178 @cindex offload test
1179 To test whether your setup is operational, run this command on the
1186 This will attempt to connect to each of the build machines specified in
1187 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1188 available on each machine, attempt to export to the machine and import
1189 from it, and report any error in the process.
1191 If you want to test a different machine file, just specify it on the
1195 # guix offload test machines-qualif.scm
1198 Last, you can test the subset of the machines whose name matches a
1199 regular expression like this:
1202 # guix offload test machines.scm '\.gnu\.org$'
1205 @cindex offload status
1206 To display the current load of all build hosts, run this command on the
1210 # guix offload status
1214 @node SELinux Support
1215 @subsection SELinux Support
1217 @cindex SELinux, daemon policy
1218 @cindex mandatory access control, SELinux
1219 @cindex security, guix-daemon
1220 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1221 can be installed on a system where SELinux is enabled, in order to label
1222 Guix files and to specify the expected behavior of the daemon. Since
1223 Guix System does not provide an SELinux base policy, the daemon policy cannot
1224 be used on Guix System.
1226 @subsubsection Installing the SELinux policy
1227 @cindex SELinux, policy installation
1228 To install the policy run this command as root:
1231 semodule -i etc/guix-daemon.cil
1234 Then relabel the file system with @code{restorecon} or by a different
1235 mechanism provided by your system.
1237 Once the policy is installed, the file system has been relabeled, and
1238 the daemon has been restarted, it should be running in the
1239 @code{guix_daemon_t} context. You can confirm this with the following
1243 ps -Zax | grep guix-daemon
1246 Monitor the SELinux log files as you run a command like @code{guix build
1247 hello} to convince yourself that SELinux permits all necessary
1250 @subsubsection Limitations
1251 @cindex SELinux, limitations
1253 This policy is not perfect. Here is a list of limitations or quirks
1254 that should be considered when deploying the provided SELinux policy for
1259 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1260 operations involve contexts that have anything to do with
1261 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1262 but it would be preferrable to define socket rules for only this label.
1265 @code{guix gc} cannot access arbitrary links to profiles. By design,
1266 the file label of the destination of a symlink is independent of the
1267 file label of the link itself. Although all profiles under
1268 $localstatedir are labelled, the links to these profiles inherit the
1269 label of the directory they are in. For links in the user’s home
1270 directory this will be @code{user_home_t}. But for links from the root
1271 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1272 directory, etc, this won’t work. @code{guix gc} would be prevented from
1273 reading and following these links.
1276 The daemon’s feature to listen for TCP connections might no longer work.
1277 This might require extra rules, because SELinux treats network sockets
1278 differently from files.
1281 Currently all files with a name matching the regular expression
1282 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1283 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1284 that name in any profile would be permitted to run in the
1285 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1286 build a package that provides this executable and convince a user to
1287 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1288 At that point SELinux could not prevent it from accessing files that are
1289 allowed for processes in that domain.
1291 We could generate a much more restrictive policy at installation time,
1292 so that only the @emph{exact} file name of the currently installed
1293 @code{guix-daemon} executable would be labelled with
1294 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1295 The downside is that root would have to install or upgrade the policy at
1296 installation time whenever the Guix package that provides the
1297 effectively running @code{guix-daemon} executable is upgraded.
1300 @node Invoking guix-daemon
1301 @section Invoking @command{guix-daemon}
1303 The @command{guix-daemon} program implements all the functionality to
1304 access the store. This includes launching build processes, running the
1305 garbage collector, querying the availability of a build result, etc. It
1306 is normally run as @code{root} like this:
1309 # guix-daemon --build-users-group=guixbuild
1313 For details on how to set it up, @pxref{Setting Up the Daemon}.
1316 @cindex container, build environment
1317 @cindex build environment
1318 @cindex reproducible builds
1319 By default, @command{guix-daemon} launches build processes under
1320 different UIDs, taken from the build group specified with
1321 @code{--build-users-group}. In addition, each build process is run in a
1322 chroot environment that only contains the subset of the store that the
1323 build process depends on, as specified by its derivation
1324 (@pxref{Programming Interface, derivation}), plus a set of specific
1325 system directories. By default, the latter contains @file{/dev} and
1326 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1327 @dfn{container}: in addition to having its own file system tree, it has
1328 a separate mount name space, its own PID name space, network name space,
1329 etc. This helps achieve reproducible builds (@pxref{Features}).
1331 When the daemon performs a build on behalf of the user, it creates a
1332 build directory under @file{/tmp} or under the directory specified by
1333 its @code{TMPDIR} environment variable. This directory is shared with
1334 the container for the duration of the build, though within the container,
1335 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1337 The build directory is automatically deleted upon completion, unless the
1338 build failed and the client specified @option{--keep-failed}
1339 (@pxref{Invoking guix build, @option{--keep-failed}}).
1341 The daemon listens for connections and spawns one sub-process for each session
1342 started by a client (one of the @command{guix} sub-commands.) The
1343 @command{guix processes} command allows you to get an overview of the activity
1344 on your system by viewing each of the active sessions and clients.
1345 @xref{Invoking guix processes}, for more information.
1347 The following command-line options are supported:
1350 @item --build-users-group=@var{group}
1351 Take users from @var{group} to run build processes (@pxref{Setting Up
1352 the Daemon, build users}).
1354 @item --no-substitutes
1356 Do not use substitutes for build products. That is, always build things
1357 locally instead of allowing downloads of pre-built binaries
1358 (@pxref{Substitutes}).
1360 When the daemon runs with @code{--no-substitutes}, clients can still
1361 explicitly enable substitution @i{via} the @code{set-build-options}
1362 remote procedure call (@pxref{The Store}).
1364 @item --substitute-urls=@var{urls}
1365 @anchor{daemon-substitute-urls}
1366 Consider @var{urls} the default whitespace-separated list of substitute
1367 source URLs. When this option is omitted,
1368 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1370 This means that substitutes may be downloaded from @var{urls}, as long
1371 as they are signed by a trusted signature (@pxref{Substitutes}).
1375 Do not use offload builds to other machines (@pxref{Daemon Offload
1376 Setup}). That is, always build things locally instead of offloading
1377 builds to remote machines.
1379 @item --cache-failures
1380 Cache build failures. By default, only successful builds are cached.
1382 When this option is used, @command{guix gc --list-failures} can be used
1383 to query the set of store items marked as failed; @command{guix gc
1384 --clear-failures} removes store items from the set of cached failures.
1385 @xref{Invoking guix gc}.
1387 @item --cores=@var{n}
1389 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1392 The default value is @code{0}, but it may be overridden by clients, such
1393 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1396 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1397 in the build process, which can then use it to exploit internal
1398 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1400 @item --max-jobs=@var{n}
1402 Allow at most @var{n} build jobs in parallel. The default value is
1403 @code{1}. Setting it to @code{0} means that no builds will be performed
1404 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1405 Setup}), or simply fail.
1407 @item --max-silent-time=@var{seconds}
1408 When the build or substitution process remains silent for more than
1409 @var{seconds}, terminate it and report a build failure.
1411 The default value is @code{0}, which disables the timeout.
1413 The value specified here can be overridden by clients (@pxref{Common
1414 Build Options, @code{--max-silent-time}}).
1416 @item --timeout=@var{seconds}
1417 Likewise, when the build or substitution process lasts for more than
1418 @var{seconds}, terminate it and report a build failure.
1420 The default value is @code{0}, which disables the timeout.
1422 The value specified here can be overridden by clients (@pxref{Common
1423 Build Options, @code{--timeout}}).
1425 @item --rounds=@var{N}
1426 Build each derivation @var{n} times in a row, and raise an error if
1427 consecutive build results are not bit-for-bit identical. Note that this
1428 setting can be overridden by clients such as @command{guix build}
1429 (@pxref{Invoking guix build}).
1431 When used in conjunction with @option{--keep-failed}, the differing
1432 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1433 This makes it easy to look for differences between the two results.
1436 Produce debugging output.
1438 This is useful to debug daemon start-up issues, but then it may be
1439 overridden by clients, for example the @code{--verbosity} option of
1440 @command{guix build} (@pxref{Invoking guix build}).
1442 @item --chroot-directory=@var{dir}
1443 Add @var{dir} to the build chroot.
1445 Doing this may change the result of build processes---for instance if
1446 they use optional dependencies found in @var{dir} when it is available,
1447 and not otherwise. For that reason, it is not recommended to do so.
1448 Instead, make sure that each derivation declares all the inputs that it
1451 @item --disable-chroot
1452 Disable chroot builds.
1454 Using this option is not recommended since, again, it would allow build
1455 processes to gain access to undeclared dependencies. It is necessary,
1456 though, when @command{guix-daemon} is running under an unprivileged user
1459 @item --log-compression=@var{type}
1460 Compress build logs according to @var{type}, one of @code{gzip},
1461 @code{bzip2}, or @code{none}.
1463 Unless @code{--lose-logs} is used, all the build logs are kept in the
1464 @var{localstatedir}. To save space, the daemon automatically compresses
1465 them with bzip2 by default.
1467 @item --disable-deduplication
1468 @cindex deduplication
1469 Disable automatic file ``deduplication'' in the store.
1471 By default, files added to the store are automatically ``deduplicated'':
1472 if a newly added file is identical to another one found in the store,
1473 the daemon makes the new file a hard link to the other file. This can
1474 noticeably reduce disk usage, at the expense of slightly increased
1475 input/output load at the end of a build process. This option disables
1478 @item --gc-keep-outputs[=yes|no]
1479 Tell whether the garbage collector (GC) must keep outputs of live
1483 @cindex garbage collector roots
1484 When set to ``yes'', the GC will keep the outputs of any live derivation
1485 available in the store---the @code{.drv} files. The default is ``no'',
1486 meaning that derivation outputs are kept only if they are reachable from a GC
1487 root. @xref{Invoking guix gc}, for more on GC roots.
1489 @item --gc-keep-derivations[=yes|no]
1490 Tell whether the garbage collector (GC) must keep derivations
1491 corresponding to live outputs.
1493 When set to ``yes'', as is the case by default, the GC keeps
1494 derivations---i.e., @code{.drv} files---as long as at least one of their
1495 outputs is live. This allows users to keep track of the origins of
1496 items in their store. Setting it to ``no'' saves a bit of disk space.
1498 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1499 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1500 ``yes'' causes liveness to flow from derivations to outputs. When both are
1501 set to ``yes'', the effect is to keep all the build prerequisites (the
1502 sources, compiler, libraries, and other build-time tools) of live objects in
1503 the store, regardless of whether these prerequisites are reachable from a GC
1504 root. This is convenient for developers since it saves rebuilds or downloads.
1506 @item --impersonate-linux-2.6
1507 On Linux-based systems, impersonate Linux 2.6. This means that the
1508 kernel's @code{uname} system call will report 2.6 as the release number.
1510 This might be helpful to build programs that (usually wrongfully) depend
1511 on the kernel version number.
1514 Do not keep build logs. By default they are kept under
1515 @code{@var{localstatedir}/guix/log}.
1517 @item --system=@var{system}
1518 Assume @var{system} as the current system type. By default it is the
1519 architecture/kernel pair found at configure time, such as
1520 @code{x86_64-linux}.
1522 @item --listen=@var{endpoint}
1523 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1524 as the file name of a Unix-domain socket if it starts with
1525 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1526 host name or host name and port to listen to. Here are a few examples:
1529 @item --listen=/gnu/var/daemon
1530 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1531 creating it if needed.
1533 @item --listen=localhost
1534 @cindex daemon, remote access
1535 @cindex remote access to the daemon
1536 @cindex daemon, cluster setup
1537 @cindex clusters, daemon setup
1538 Listen for TCP connections on the network interface corresponding to
1539 @code{localhost}, on port 44146.
1541 @item --listen=128.0.0.42:1234
1542 Listen for TCP connections on the network interface corresponding to
1543 @code{128.0.0.42}, on port 1234.
1546 This option can be repeated multiple times, in which case
1547 @command{guix-daemon} accepts connections on all the specified
1548 endpoints. Users can tell client commands what endpoint to connect to
1549 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1550 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1553 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1554 @code{--listen=@var{host}} is suitable on local networks, such as
1555 clusters, where only trusted nodes may connect to the build daemon. In
1556 other cases where remote access to the daemon is needed, we recommend
1557 using Unix-domain sockets along with SSH.
1560 When @code{--listen} is omitted, @command{guix-daemon} listens for
1561 connections on the Unix-domain socket located at
1562 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1566 @node Application Setup
1567 @section Application Setup
1569 @cindex foreign distro
1570 When using Guix on top of GNU/Linux distribution other than Guix System---a
1571 so-called @dfn{foreign distro}---a few additional steps are needed to
1572 get everything in place. Here are some of them.
1576 @anchor{locales-and-locpath}
1577 @cindex locales, when not on Guix System
1579 @vindex GUIX_LOCPATH
1580 Packages installed @i{via} Guix will not use the locale data of the
1581 host system. Instead, you must first install one of the locale packages
1582 available with Guix and then define the @code{GUIX_LOCPATH} environment
1586 $ guix install glibc-locales
1587 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1590 Note that the @code{glibc-locales} package contains data for all the
1591 locales supported by the GNU@tie{}libc and weighs in at around
1592 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1593 limited to a few UTF-8 locales.
1595 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1596 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1597 Manual}). There are two important differences though:
1601 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1602 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1603 to make sure the programs of the foreign distro will not end up loading
1604 incompatible locale data.
1607 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1608 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1609 should your Guix profile contain a mixture of programs linked against
1610 different libc version, each libc version will only try to load locale
1611 data in the right format.
1614 This is important because the locale data format used by different libc
1615 versions may be incompatible.
1617 @subsection Name Service Switch
1619 @cindex name service switch, glibc
1620 @cindex NSS (name service switch), glibc
1621 @cindex nscd (name service caching daemon)
1622 @cindex name service caching daemon (nscd)
1623 When using Guix on a foreign distro, we @emph{strongly recommend} that
1624 the system run the GNU C library's @dfn{name service cache daemon},
1625 @command{nscd}, which should be listening on the
1626 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1627 installed with Guix may fail to look up host names or user accounts, or
1628 may even crash. The next paragraphs explain why.
1630 @cindex @file{nsswitch.conf}
1631 The GNU C library implements a @dfn{name service switch} (NSS), which is
1632 an extensible mechanism for ``name lookups'' in general: host name
1633 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1634 The GNU C Library Reference Manual}).
1636 @cindex Network information service (NIS)
1637 @cindex NIS (Network information service)
1638 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1639 lookup implementations: for example, the @code{nss-mdns} plugin allow
1640 resolution of @code{.local} host names, the @code{nis} plugin allows
1641 user account lookup using the Network information service (NIS), and so
1642 on. These extra ``lookup services'' are configured system-wide in
1643 @file{/etc/nsswitch.conf}, and all the programs running on the system
1644 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1647 When they perform a name lookup---for instance by calling the
1648 @code{getaddrinfo} function in C---applications first try to connect to
1649 the nscd; on success, nscd performs name lookups on their behalf. If
1650 the nscd is not running, then they perform the name lookup by
1651 themselves, by loading the name lookup services into their own address
1652 space and running it. These name lookup services---the
1653 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1654 the host system's C library, rather than from the C library the
1655 application is linked against (the C library coming from Guix).
1657 And this is where the problem is: if your application is linked against
1658 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1659 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1660 likely crash or have its name lookups fail unexpectedly.
1662 Running @command{nscd} on the system, among other advantages, eliminates
1663 this binary incompatibility problem because those @code{libnss_*.so}
1664 files are loaded in the @command{nscd} process, not in applications
1667 @subsection X11 Fonts
1670 The majority of graphical applications use Fontconfig to locate and
1671 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1672 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1673 by default. Thus, to allow graphical applications installed with Guix
1674 to display fonts, you have to install fonts with Guix as well.
1675 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1676 @code{font-gnu-freefont-ttf}.
1678 To display text written in Chinese languages, Japanese, or Korean in
1679 graphical applications, consider installing
1680 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1681 has multiple outputs, one per language family (@pxref{Packages with
1682 Multiple Outputs}). For instance, the following command installs fonts
1683 for Chinese languages:
1686 guix install font-adobe-source-han-sans:cn
1689 @cindex @code{xterm}
1690 Older programs such as @command{xterm} do not use Fontconfig and instead
1691 rely on server-side font rendering. Such programs require to specify a
1692 full name of a font using XLFD (X Logical Font Description), like this:
1695 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1698 To be able to use such full names for the TrueType fonts installed in
1699 your Guix profile, you need to extend the font path of the X server:
1701 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1702 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1704 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1707 @cindex @code{xlsfonts}
1708 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1709 to make sure your TrueType fonts are listed there.
1711 @cindex @code{fc-cache}
1713 After installing fonts you may have to refresh the font cache to use
1714 them in applications. The same applies when applications installed via
1715 Guix do not seem to find fonts. To force rebuilding of the font cache
1716 run @code{fc-cache -rv}. The @code{fc-cache} command is provided by
1717 the @code{fontconfig} package.
1719 @subsection X.509 Certificates
1721 @cindex @code{nss-certs}
1722 The @code{nss-certs} package provides X.509 certificates, which allow
1723 programs to authenticate Web servers accessed over HTTPS.
1725 When using Guix on a foreign distro, you can install this package and
1726 define the relevant environment variables so that packages know where to
1727 look for certificates. @xref{X.509 Certificates}, for detailed
1730 @subsection Emacs Packages
1732 @cindex @code{emacs}
1733 When you install Emacs packages with Guix, the elisp files may be placed
1734 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1736 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1737 directory exists because potentially there may exist thousands of Emacs
1738 packages and storing all their files in a single directory may not be
1739 reliable (because of name conflicts). So we think using a separate
1740 directory for each package is a good idea. It is very similar to how
1741 the Emacs package system organizes the file structure (@pxref{Package
1742 Files,,, emacs, The GNU Emacs Manual}).
1744 By default, Emacs (installed with Guix) ``knows'' where these packages
1745 are placed, so you do not need to perform any configuration. If, for
1746 some reason, you want to avoid auto-loading Emacs packages installed
1747 with Guix, you can do so by running Emacs with @code{--no-site-file}
1748 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1750 @subsection The GCC toolchain
1755 Guix offers individual compiler packages such as @code{gcc} but if you
1756 are in need of a complete toolchain for compiling and linking source
1757 code what you really want is the @code{gcc-toolchain} package. This
1758 package provides a complete GCC toolchain for C/C++ development,
1759 including GCC itself, the GNU C Library (headers and binaries, plus
1760 debugging symbols in the @code{debug} output), Binutils, and a linker
1763 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1764 passed to the linker, add corresponding @code{-rpath} arguments, and
1765 invoke the actual linker with this new set of arguments. You can instruct the
1766 wrapper to refuse to link against libraries not in the store by setting the
1767 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1769 @node Upgrading Guix
1770 @section Upgrading Guix
1772 @cindex Upgrading Guix, on a foreign distro
1774 To upgrade Guix, run:
1780 @xref{Invoking guix pull}, for more information.
1782 @cindex upgrading Guix for the root user, on a foreign distro
1783 @cindex upgrading the Guix daemon, on a foreign distro
1784 @cindex @command{guix pull} for the root user, on a foreign distro
1786 On a foreign distro, you can upgrade the build daemon by running:
1793 followed by (assuming your distro uses the systemd service management
1797 systemctl restart guix-daemon.service
1800 On Guix System, upgrading the daemon is achieved by reconfiguring the
1801 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1805 @c *********************************************************************
1806 @node System Installation
1807 @chapter System Installation
1809 @cindex installing Guix System
1810 @cindex Guix System, installation
1811 This section explains how to install Guix System
1812 on a machine. Guix, as a package manager, can
1813 also be installed on top of a running GNU/Linux system,
1814 @pxref{Installation}.
1818 @c This paragraph is for people reading this from tty2 of the
1819 @c installation image.
1820 You are reading this documentation with an Info reader. For details on
1821 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1822 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1823 Info}. Hit @kbd{l} afterwards to come back here.
1825 Alternately, run @command{info info} in another tty to keep the manual
1831 * Limitations:: What you can expect.
1832 * Hardware Considerations:: Supported hardware.
1833 * USB Stick and DVD Installation:: Preparing the installation medium.
1834 * Preparing for Installation:: Networking, partitioning, etc.
1835 * Guided Graphical Installation:: Easy graphical installation.
1836 * Manual Installation:: Manual installation for wizards.
1837 * After System Installation:: When installation succeeded.
1838 * Installing Guix in a VM:: Guix System playground.
1839 * Building the Installation Image:: How this comes to be.
1843 @section Limitations
1845 We consider Guix System to be ready for a wide range of ``desktop'' and server
1846 use cases. The reliability guarantees it provides---transactional upgrades
1847 and rollbacks, reproducibility---make it a solid foundation.
1849 Nevertheless, before you proceed with the installation, be aware of the
1850 following noteworthy limitations applicable to version @value{VERSION}:
1854 Support for the Logical Volume Manager (LVM) is missing.
1857 More and more system services are provided (@pxref{Services}), but some
1861 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1862 as well as a number of X11 window managers. However, KDE is currently
1866 More than a disclaimer, this is an invitation to report issues (and success
1867 stories!), and to join us in improving it. @xref{Contributing}, for more
1871 @node Hardware Considerations
1872 @section Hardware Considerations
1874 @cindex hardware support on Guix System
1875 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1876 builds around the kernel Linux-libre, which means that only hardware for
1877 which free software drivers and firmware exist is supported. Nowadays,
1878 a wide range of off-the-shelf hardware is supported on
1879 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1880 Ethernet controllers. Unfortunately, there are still areas where
1881 hardware vendors deny users control over their own computing, and such
1882 hardware is not supported on Guix System.
1884 @cindex WiFi, hardware support
1885 One of the main areas where free drivers or firmware are lacking is WiFi
1886 devices. WiFi devices known to work include those using Atheros chips
1887 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1888 driver, and those using Broadcom/AirForce chips (BCM43xx with
1889 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1890 Linux-libre driver. Free firmware exists for both and is available
1891 out-of-the-box on Guix System, as part of @code{%base-firmware}
1892 (@pxref{operating-system Reference, @code{firmware}}).
1894 @cindex RYF, Respects Your Freedom
1895 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1896 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1897 certification program for hardware products that respect your freedom
1898 and your privacy and ensure that you have control over your device. We
1899 encourage you to check the list of RYF-certified devices.
1901 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1902 web site. It contains a catalog of hardware devices with information
1903 about their support in GNU/Linux.
1906 @node USB Stick and DVD Installation
1907 @section USB Stick and DVD Installation
1909 An ISO-9660 installation image that can be written to a USB stick or
1910 burnt to a DVD can be downloaded from
1911 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1912 where @var{system} is one of:
1916 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1919 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1922 @c start duplication of authentication part from ``Binary Installation''
1923 Make sure to download the associated @file{.sig} file and to verify the
1924 authenticity of the image against it, along these lines:
1927 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1928 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1931 If that command fails because you do not have the required public key,
1932 then run this command to import it:
1935 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1936 -qO - | gpg --import -
1940 and rerun the @code{gpg --verify} command.
1942 Take note that a warning like ``This key is not certified with a trusted
1943 signature!'' is normal.
1947 This image contains the tools necessary for an installation.
1948 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1950 @unnumberedsubsec Copying to a USB Stick
1952 To copy the image to a USB stick, follow these steps:
1956 Decompress the image using the @command{xz} command:
1959 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1963 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1964 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1965 copy the image with:
1968 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1972 Access to @file{/dev/sdX} usually requires root privileges.
1975 @unnumberedsubsec Burning on a DVD
1977 To copy the image to a DVD, follow these steps:
1981 Decompress the image using the @command{xz} command:
1984 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1988 Insert a blank DVD into your machine, and determine
1989 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1990 copy the image with:
1993 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1996 Access to @file{/dev/srX} usually requires root privileges.
1999 @unnumberedsubsec Booting
2001 Once this is done, you should be able to reboot the system and boot from
2002 the USB stick or DVD. The latter usually requires you to get in the
2003 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2005 @xref{Installing Guix in a VM}, if, instead, you would like to install
2006 Guix System in a virtual machine (VM).
2009 @node Preparing for Installation
2010 @section Preparing for Installation
2012 Once you have booted, you can use the guided graphical installer, which makes
2013 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2014 if you are already familiar with GNU/Linux and if you want more control than
2015 what the graphical installer provides, you can choose the ``manual''
2016 installation process (@pxref{Manual Installation}).
2018 The graphical installer is available on TTY1. You can obtain root shells on
2019 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2020 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2021 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2022 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2023 which allows you to select text with the left mouse button and to paste it
2024 with the middle button.
2027 Installation requires access to the Internet so that any missing
2028 dependencies of your system configuration can be downloaded. See the
2029 ``Networking'' section below.
2032 @node Guided Graphical Installation
2033 @section Guided Graphical Installation
2035 The graphical installer is a text-based user interface. It will guide you,
2036 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2038 The first dialog boxes allow you to set up the system as you use it during the
2039 installation: you can choose the language, keyboard layout, and set up
2040 networking, which will be used during the installation. The image below shows
2041 the networking dialog.
2043 @image{images/installer-network,5in,, networking setup with the graphical installer}
2045 Later steps allow you to partition your hard disk, as shown in the image
2046 below, to choose whether or not to use encrypted file systems, to enter the
2047 host name and root password, and to create an additional account, among other
2050 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2052 Note that, at any time, the installer allows you to exit the current
2053 installation step and resume at a previous step, as show in the image below.
2055 @image{images/installer-resume,5in,, resuming the installation process}
2057 Once you're done, the installer produces an operating system configuration and
2058 displays it (@pxref{Using the Configuration System}). At that point you can
2059 hit ``OK'' and installation will proceed. On success, you can reboot into the
2060 new system and enjoy. @xref{After System Installation}, for what's next!
2063 @node Manual Installation
2064 @section Manual Installation
2066 This section describes how you would ``manually'' install GNU@tie{}Guix System
2067 on your machine. This option requires familiarity with GNU/Linux, with the
2068 shell, and with common administration tools. If you think this is not for
2069 you, consider using the guided graphical installer (@pxref{Guided Graphical
2072 The installation system provides root shells on TTYs 3 to 6; press
2073 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2074 many common tools needed to install the system. But it is also a full-blown
2075 Guix System, which means that you can install additional packages, should you
2076 need it, using @command{guix package} (@pxref{Invoking guix package}).
2079 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2080 * Proceeding with the Installation:: Installing.
2083 @node Keyboard Layout and Networking and Partitioning
2084 @subsection Keyboard Layout, Networking, and Partitioning
2086 Before you can install the system, you may want to adjust the keyboard layout,
2087 set up networking, and partition your target hard disk. This section will
2088 guide you through this.
2090 @subsubsection Keyboard Layout
2092 @cindex keyboard layout
2093 The installation image uses the US qwerty keyboard layout. If you want
2094 to change it, you can use the @command{loadkeys} command. For example,
2095 the following command selects the Dvorak keyboard layout:
2101 See the files under @file{/run/current-system/profile/share/keymaps} for
2102 a list of available keyboard layouts. Run @command{man loadkeys} for
2105 @subsubsection Networking
2107 Run the following command to see what your network interfaces are called:
2114 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2120 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2121 Wired interfaces have a name starting with @samp{e}; for example, the
2122 interface corresponding to the first on-board Ethernet controller is
2123 called @samp{eno1}. Wireless interfaces have a name starting with
2124 @samp{w}, like @samp{w1p2s0}.
2127 @item Wired connection
2128 To configure a wired network run the following command, substituting
2129 @var{interface} with the name of the wired interface you want to use.
2132 ifconfig @var{interface} up
2136 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2139 ip link set @var{interface} up
2142 @item Wireless connection
2145 To configure wireless networking, you can create a configuration file
2146 for the @command{wpa_supplicant} configuration tool (its location is not
2147 important) using one of the available text editors such as
2151 nano wpa_supplicant.conf
2154 As an example, the following stanza can go to this file and will work
2155 for many wireless networks, provided you give the actual SSID and
2156 passphrase for the network you are connecting to:
2160 ssid="@var{my-ssid}"
2162 psk="the network's secret passphrase"
2166 Start the wireless service and run it in the background with the
2167 following command (substitute @var{interface} with the name of the
2168 network interface you want to use):
2171 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2174 Run @command{man wpa_supplicant} for more information.
2178 At this point, you need to acquire an IP address. On a network where IP
2179 addresses are automatically assigned @i{via} DHCP, you can run:
2182 dhclient -v @var{interface}
2185 Try to ping a server to see if networking is up and running:
2191 Setting up network access is almost always a requirement because the
2192 image does not contain all the software and tools that may be needed.
2194 @cindex installing over SSH
2195 If you want to, you can continue the installation remotely by starting
2199 herd start ssh-daemon
2202 Make sure to either set a password with @command{passwd}, or configure
2203 OpenSSH public key authentication before logging in.
2205 @subsubsection Disk Partitioning
2207 Unless this has already been done, the next step is to partition, and
2208 then format the target partition(s).
2210 The installation image includes several partitioning tools, including
2211 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2212 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2213 the partition layout you want:
2219 If your disk uses the GUID Partition Table (GPT) format and you plan to
2220 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2221 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2224 @cindex EFI, installation
2225 @cindex UEFI, installation
2226 @cindex ESP, EFI system partition
2227 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2228 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2229 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2232 parted /dev/sda set 1 esp on
2236 @vindex grub-bootloader
2237 @vindex grub-efi-bootloader
2238 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2239 @file{/sys/firmware/efi} exists in the installation image, then you should
2240 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2241 Otherwise you should use the BIOS-based GRUB, known as
2242 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2246 Once you are done partitioning the target hard disk drive, you have to
2247 create a file system on the relevant partition(s)@footnote{Currently
2248 Guix System only supports ext4 and btrfs file systems. In particular, code
2249 that reads file system UUIDs and labels only works for these file system
2250 types.}. For the ESP, if you have one and assuming it is
2251 @file{/dev/sda1}, run:
2254 mkfs.fat -F32 /dev/sda1
2257 Preferably, assign file systems a label so that you can easily and
2258 reliably refer to them in @code{file-system} declarations (@pxref{File
2259 Systems}). This is typically done using the @code{-L} option of
2260 @command{mkfs.ext4} and related commands. So, assuming the target root
2261 partition lives at @file{/dev/sda2}, a file system with the label
2262 @code{my-root} can be created with:
2265 mkfs.ext4 -L my-root /dev/sda2
2268 @cindex encrypted disk
2269 If you are instead planning to encrypt the root partition, you can use
2270 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2271 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2272 @code{man cryptsetup}} for more information.) Assuming you want to
2273 store the root partition on @file{/dev/sda2}, the command sequence would
2274 be along these lines:
2277 cryptsetup luksFormat /dev/sda2
2278 cryptsetup open --type luks /dev/sda2 my-partition
2279 mkfs.ext4 -L my-root /dev/mapper/my-partition
2282 Once that is done, mount the target file system under @file{/mnt}
2283 with a command like (again, assuming @code{my-root} is the label of the
2287 mount LABEL=my-root /mnt
2290 Also mount any other file systems you would like to use on the target
2291 system relative to this path. If you have opted for @file{/boot/efi} as an
2292 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2293 found by @code{guix system init} afterwards.
2295 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2296 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2297 sure to initialize them with @command{mkswap}. Assuming you have one
2298 swap partition on @file{/dev/sda3}, you would run:
2305 Alternatively, you may use a swap file. For example, assuming that in
2306 the new system you want to use the file @file{/swapfile} as a swap file,
2307 you would run@footnote{This example will work for many types of file
2308 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2309 btrfs), the required steps may be different. For details, see the
2310 manual pages for @command{mkswap} and @command{swapon}.}:
2313 # This is 10 GiB of swap space. Adjust "count" to change the size.
2314 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2315 # For security, make the file readable and writable only by root.
2316 chmod 600 /mnt/swapfile
2317 mkswap /mnt/swapfile
2318 swapon /mnt/swapfile
2321 Note that if you have encrypted the root partition and created a swap
2322 file in its file system as described above, then the encryption also
2323 protects the swap file, just like any other file in that file system.
2325 @node Proceeding with the Installation
2326 @subsection Proceeding with the Installation
2328 With the target partitions ready and the target root mounted on
2329 @file{/mnt}, we're ready to go. First, run:
2332 herd start cow-store /mnt
2335 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2336 during the installation phase are written to the target disk on @file{/mnt}
2337 rather than kept in memory. This is necessary because the first phase of
2338 the @command{guix system init} command (see below) entails downloads or
2339 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2341 Next, you have to edit a file and
2342 provide the declaration of the operating system to be installed. To
2343 that end, the installation system comes with three text editors. We
2344 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2345 supports syntax highlighting and parentheses matching; other editors
2346 include GNU Zile (an Emacs clone), and
2347 nvi (a clone of the original BSD @command{vi} editor).
2348 We strongly recommend storing that file on the target root file system, say,
2349 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2350 configuration file once you have rebooted into the newly-installed system.
2352 @xref{Using the Configuration System}, for an overview of the
2353 configuration file. The example configurations discussed in that
2354 section are available under @file{/etc/configuration} in the
2355 installation image. Thus, to get started with a system configuration
2356 providing a graphical display server (a ``desktop'' system), you can run
2357 something along these lines:
2361 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2362 # nano /mnt/etc/config.scm
2365 You should pay attention to what your configuration file contains, and
2370 Make sure the @code{bootloader-configuration} form refers to the target
2371 you want to install GRUB on. It should mention @code{grub-bootloader} if
2372 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2373 for newer UEFI systems. For legacy systems, the @code{target} field
2374 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2375 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2376 currently mounted and a @code{file-system} entry is specified in your
2380 Be sure that your file system labels match the value of their respective
2381 @code{device} fields in your @code{file-system} configuration, assuming
2382 your @code{file-system} configuration uses the @code{file-system-label}
2383 procedure in its @code{device} field.
2386 If there are encrypted or RAID partitions, make sure to add a
2387 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2390 Once you are done preparing the configuration file, the new system must
2391 be initialized (remember that the target root file system is mounted
2395 guix system init /mnt/etc/config.scm /mnt
2399 This copies all the necessary files and installs GRUB on
2400 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2401 more information, @pxref{Invoking guix system}. This command may trigger
2402 downloads or builds of missing packages, which can take some time.
2404 Once that command has completed---and hopefully succeeded!---you can run
2405 @command{reboot} and boot into the new system. The @code{root} password
2406 in the new system is initially empty; other users' passwords need to be
2407 initialized by running the @command{passwd} command as @code{root},
2408 unless your configuration specifies otherwise
2409 (@pxref{user-account-password, user account passwords}).
2410 @xref{After System Installation}, for what's next!
2413 @node After System Installation
2414 @section After System Installation
2416 Success, you've now booted into Guix System! From then on, you can update the
2417 system whenever you want by running, say:
2421 sudo guix system reconfigure /etc/config.scm
2425 This builds a new system generation with the latest packages and services
2426 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2427 your system includes the latest security updates (@pxref{Security Updates}).
2429 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2431 @cindex sudo vs. @command{guix pull}
2432 Note that @command{sudo guix} runs your user's @command{guix} command and
2433 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2434 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2437 Join us on @code{#guix} on the Freenode IRC network or on
2438 @email{guix-devel@@gnu.org} to share your experience!
2441 @node Installing Guix in a VM
2442 @section Installing Guix in a Virtual Machine
2444 @cindex virtual machine, Guix System installation
2445 @cindex virtual private server (VPS)
2446 @cindex VPS (virtual private server)
2447 If you'd like to install Guix System in a virtual machine (VM) or on a
2448 virtual private server (VPS) rather than on your beloved machine, this
2451 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2452 disk image, follow these steps:
2456 First, retrieve and decompress the Guix system installation image as
2457 described previously (@pxref{USB Stick and DVD Installation}).
2460 Create a disk image that will hold the installed system. To make a
2461 qcow2-formatted disk image, use the @command{qemu-img} command:
2464 qemu-img create -f qcow2 guix-system.img 50G
2467 The resulting file will be much smaller than 50 GB (typically less than
2468 1 MB), but it will grow as the virtualized storage device is filled up.
2471 Boot the USB installation image in an VM:
2474 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2475 -net user -net nic,model=virtio -boot menu=on,order=d \
2476 -drive file=guix-system.img \
2477 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2480 @code{-enable-kvm} is optional, but significantly improves performance,
2481 @pxref{Running Guix in a VM}.
2484 You're now root in the VM, proceed with the installation process.
2485 @xref{Preparing for Installation}, and follow the instructions.
2488 Once installation is complete, you can boot the system that's on your
2489 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2492 @node Building the Installation Image
2493 @section Building the Installation Image
2495 @cindex installation image
2496 The installation image described above was built using the @command{guix
2497 system} command, specifically:
2500 guix system disk-image --file-system-type=iso9660 \
2501 gnu/system/install.scm
2504 Have a look at @file{gnu/system/install.scm} in the source tree,
2505 and see also @ref{Invoking guix system} for more information
2506 about the installation image.
2508 @section Building the Installation Image for ARM Boards
2510 Many ARM boards require a specific variant of the
2511 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2513 If you build a disk image and the bootloader is not available otherwise
2514 (on another boot drive etc), it's advisable to build an image that
2515 includes the bootloader, specifically:
2518 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2521 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2522 board, a list of possible boards will be printed.
2524 @c *********************************************************************
2525 @node Package Management
2526 @chapter Package Management
2529 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2530 remove software packages, without having to know about their build
2531 procedures or dependencies. Guix also goes beyond this obvious set of
2534 This chapter describes the main features of Guix, as well as the
2535 package management tools it provides. Along with the command-line
2536 interface described below (@pxref{Invoking guix package, @code{guix
2537 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2538 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2539 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2543 guix install emacs-guix
2547 * Features:: How Guix will make your life brighter.
2548 * Invoking guix package:: Package installation, removal, etc.
2549 * Substitutes:: Downloading pre-built binaries.
2550 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2551 * Invoking guix gc:: Running the garbage collector.
2552 * Invoking guix pull:: Fetching the latest Guix and distribution.
2553 * Channels:: Customizing the package collection.
2554 * Invoking guix time-machine:: Running an older revision of Guix.
2555 * Inferiors:: Interacting with another revision of Guix.
2556 * Invoking guix describe:: Display information about your Guix revision.
2557 * Invoking guix archive:: Exporting and importing store files.
2563 When using Guix, each package ends up in the @dfn{package store}, in its
2564 own directory---something that resembles
2565 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2567 Instead of referring to these directories, users have their own
2568 @dfn{profile}, which points to the packages that they actually want to
2569 use. These profiles are stored within each user's home directory, at
2570 @code{$HOME/.guix-profile}.
2572 For example, @code{alice} installs GCC 4.7.2. As a result,
2573 @file{/home/alice/.guix-profile/bin/gcc} points to
2574 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2575 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2576 simply continues to point to
2577 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2578 coexist on the same system without any interference.
2580 The @command{guix package} command is the central tool to manage
2581 packages (@pxref{Invoking guix package}). It operates on the per-user
2582 profiles, and can be used @emph{with normal user privileges}.
2584 @cindex transactions
2585 The command provides the obvious install, remove, and upgrade
2586 operations. Each invocation is actually a @emph{transaction}: either
2587 the specified operation succeeds, or nothing happens. Thus, if the
2588 @command{guix package} process is terminated during the transaction,
2589 or if a power outage occurs during the transaction, then the user's
2590 profile remains in its previous state, and remains usable.
2592 In addition, any package transaction may be @emph{rolled back}. So, if,
2593 for example, an upgrade installs a new version of a package that turns
2594 out to have a serious bug, users may roll back to the previous instance
2595 of their profile, which was known to work well. Similarly, the global
2596 system configuration on Guix is subject to
2597 transactional upgrades and roll-back
2598 (@pxref{Using the Configuration System}).
2600 All packages in the package store may be @emph{garbage-collected}.
2601 Guix can determine which packages are still referenced by user
2602 profiles, and remove those that are provably no longer referenced
2603 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2604 generations of their profile so that the packages they refer to can be
2607 @cindex reproducibility
2608 @cindex reproducible builds
2609 Guix takes a @dfn{purely functional} approach to package
2610 management, as described in the introduction (@pxref{Introduction}).
2611 Each @file{/gnu/store} package directory name contains a hash of all the
2612 inputs that were used to build that package---compiler, libraries, build
2613 scripts, etc. This direct correspondence allows users to make sure a
2614 given package installation matches the current state of their
2615 distribution. It also helps maximize @dfn{build reproducibility}:
2616 thanks to the isolated build environments that are used, a given build
2617 is likely to yield bit-identical files when performed on different
2618 machines (@pxref{Invoking guix-daemon, container}).
2621 This foundation allows Guix to support @dfn{transparent binary/source
2622 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2623 available from an external source---a @dfn{substitute}, Guix just
2624 downloads it and unpacks it;
2625 otherwise, it builds the package from source, locally
2626 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2627 reproducible, users do not have to trust servers that provide
2628 substitutes: they can force a local build and @emph{challenge} providers
2629 (@pxref{Invoking guix challenge}).
2631 Control over the build environment is a feature that is also useful for
2632 developers. The @command{guix environment} command allows developers of
2633 a package to quickly set up the right development environment for their
2634 package, without having to manually install the dependencies of the
2635 package into their profile (@pxref{Invoking guix environment}).
2637 @cindex replication, of software environments
2638 @cindex provenance tracking, of software artifacts
2639 All of Guix and its package definitions is version-controlled, and
2640 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2641 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2642 Guix instance on a different machine or at a later point in time, which in
2643 turn allows you to @emph{replicate complete software environments}, while
2644 retaining precise @dfn{provenance tracking} of the software.
2646 @node Invoking guix package
2647 @section Invoking @command{guix package}
2649 @cindex installing packages
2650 @cindex removing packages
2651 @cindex package installation
2652 @cindex package removal
2653 The @command{guix package} command is the tool that allows users to
2654 install, upgrade, and remove packages, as well as rolling back to
2655 previous configurations. It operates only on the user's own profile,
2656 and works with normal user privileges (@pxref{Features}). Its syntax
2660 guix package @var{options}
2663 @cindex transactions
2664 Primarily, @var{options} specifies the operations to be performed during
2665 the transaction. Upon completion, a new profile is created, but
2666 previous @dfn{generations} of the profile remain available, should the user
2669 For example, to remove @code{lua} and install @code{guile} and
2670 @code{guile-cairo} in a single transaction:
2673 guix package -r lua -i guile guile-cairo
2676 @cindex aliases, for @command{guix package}
2677 For your convenience, we also provide the following aliases:
2681 @command{guix search} is an alias for @command{guix package -s},
2683 @command{guix install} is an alias for @command{guix package -i},
2685 @command{guix remove} is an alias for @command{guix package -r},
2687 @command{guix upgrade} is an alias for @command{guix package -u},
2689 and @command{guix show} is an alias for @command{guix package --show=}.
2692 These aliases are less expressive than @command{guix package} and provide
2693 fewer options, so in some cases you'll probably want to use @command{guix
2696 @command{guix package} also supports a @dfn{declarative approach}
2697 whereby the user specifies the exact set of packages to be available and
2698 passes it @i{via} the @option{--manifest} option
2699 (@pxref{profile-manifest, @option{--manifest}}).
2702 For each user, a symlink to the user's default profile is automatically
2703 created in @file{$HOME/.guix-profile}. This symlink always points to the
2704 current generation of the user's default profile. Thus, users can add
2705 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2706 variable, and so on.
2707 @cindex search paths
2708 If you are not using Guix System, consider adding the
2709 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2710 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2711 shells get all the right environment variable definitions:
2714 GUIX_PROFILE="$HOME/.guix-profile" ; \
2715 source "$HOME/.guix-profile/etc/profile"
2718 In a multi-user setup, user profiles are stored in a place registered as
2719 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2720 to (@pxref{Invoking guix gc}). That directory is normally
2721 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2722 @var{localstatedir} is the value passed to @code{configure} as
2723 @code{--localstatedir}, and @var{user} is the user name. The
2724 @file{per-user} directory is created when @command{guix-daemon} is
2725 started, and the @var{user} sub-directory is created by @command{guix
2728 The @var{options} can be among the following:
2732 @item --install=@var{package} @dots{}
2733 @itemx -i @var{package} @dots{}
2734 Install the specified @var{package}s.
2736 Each @var{package} may specify either a simple package name, such as
2737 @code{guile}, or a package name followed by an at-sign and version number,
2738 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2739 case, the newest version prefixed by @code{1.8} is selected.)
2741 If no version number is specified, the
2742 newest available version will be selected. In addition, @var{package}
2743 may contain a colon, followed by the name of one of the outputs of the
2744 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2745 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2746 name (and optionally version) are searched for among the GNU
2747 distribution modules (@pxref{Package Modules}).
2749 @cindex propagated inputs
2750 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2751 that automatically get installed along with the required package
2752 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2753 @code{package} objects}, for information about propagated inputs in
2754 package definitions).
2756 @anchor{package-cmd-propagated-inputs}
2757 An example is the GNU MPC library: its C header files refer to those of
2758 the GNU MPFR library, which in turn refer to those of the GMP library.
2759 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2760 in the profile; removing MPC also removes MPFR and GMP---unless they had
2761 also been explicitly installed by the user.
2763 Besides, packages sometimes rely on the definition of environment
2764 variables for their search paths (see explanation of
2765 @code{--search-paths} below). Any missing or possibly incorrect
2766 environment variable definitions are reported here.
2768 @item --install-from-expression=@var{exp}
2770 Install the package @var{exp} evaluates to.
2772 @var{exp} must be a Scheme expression that evaluates to a
2773 @code{<package>} object. This option is notably useful to disambiguate
2774 between same-named variants of a package, with expressions such as
2775 @code{(@@ (gnu packages base) guile-final)}.
2777 Note that this option installs the first output of the specified
2778 package, which may be insufficient when needing a specific output of a
2779 multiple-output package.
2781 @item --install-from-file=@var{file}
2782 @itemx -f @var{file}
2783 Install the package that the code within @var{file} evaluates to.
2785 As an example, @var{file} might contain a definition like this
2786 (@pxref{Defining Packages}):
2789 @include package-hello.scm
2792 Developers may find it useful to include such a @file{guix.scm} file
2793 in the root of their project source tree that can be used to test
2794 development snapshots and create reproducible development environments
2795 (@pxref{Invoking guix environment}).
2797 @item --remove=@var{package} @dots{}
2798 @itemx -r @var{package} @dots{}
2799 Remove the specified @var{package}s.
2801 As for @code{--install}, each @var{package} may specify a version number
2802 and/or output name in addition to the package name. For instance,
2803 @code{-r glibc:debug} would remove the @code{debug} output of
2806 @item --upgrade[=@var{regexp} @dots{}]
2807 @itemx -u [@var{regexp} @dots{}]
2808 @cindex upgrading packages
2809 Upgrade all the installed packages. If one or more @var{regexp}s are
2810 specified, upgrade only installed packages whose name matches a
2811 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2813 Note that this upgrades package to the latest version of packages found
2814 in the distribution currently installed. To update your distribution,
2815 you should regularly run @command{guix pull} (@pxref{Invoking guix
2818 @item --do-not-upgrade[=@var{regexp} @dots{}]
2819 When used together with the @code{--upgrade} option, do @emph{not}
2820 upgrade any packages whose name matches a @var{regexp}. For example, to
2821 upgrade all packages in the current profile except those containing the
2822 substring ``emacs'':
2825 $ guix package --upgrade . --do-not-upgrade emacs
2828 @item @anchor{profile-manifest}--manifest=@var{file}
2829 @itemx -m @var{file}
2830 @cindex profile declaration
2831 @cindex profile manifest
2832 Create a new generation of the profile from the manifest object
2833 returned by the Scheme code in @var{file}. This option can be repeated
2834 several times, in which case the manifests are concatenated.
2836 This allows you to @emph{declare} the profile's contents rather than
2837 constructing it through a sequence of @code{--install} and similar
2838 commands. The advantage is that @var{file} can be put under version
2839 control, copied to different machines to reproduce the same profile, and
2842 @c FIXME: Add reference to (guix profile) documentation when available.
2843 @var{file} must return a @dfn{manifest} object, which is roughly a list
2846 @findex packages->manifest
2848 (use-package-modules guile emacs)
2853 ;; Use a specific package output.
2854 (list guile-2.0 "debug")))
2857 @findex specifications->manifest
2858 In this example we have to know which modules define the @code{emacs}
2859 and @code{guile-2.0} variables to provide the right
2860 @code{use-package-modules} line, which can be cumbersome. We can
2861 instead provide regular package specifications and let
2862 @code{specifications->manifest} look up the corresponding package
2866 (specifications->manifest
2867 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2871 @cindex rolling back
2872 @cindex undoing transactions
2873 @cindex transactions, undoing
2874 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2875 the last transaction.
2877 When combined with options such as @code{--install}, roll back occurs
2878 before any other actions.
2880 When rolling back from the first generation that actually contains
2881 installed packages, the profile is made to point to the @dfn{zeroth
2882 generation}, which contains no files apart from its own metadata.
2884 After having rolled back, installing, removing, or upgrading packages
2885 overwrites previous future generations. Thus, the history of the
2886 generations in a profile is always linear.
2888 @item --switch-generation=@var{pattern}
2889 @itemx -S @var{pattern}
2891 Switch to a particular generation defined by @var{pattern}.
2893 @var{pattern} may be either a generation number or a number prefixed
2894 with ``+'' or ``-''. The latter means: move forward/backward by a
2895 specified number of generations. For example, if you want to return to
2896 the latest generation after @code{--roll-back}, use
2897 @code{--switch-generation=+1}.
2899 The difference between @code{--roll-back} and
2900 @code{--switch-generation=-1} is that @code{--switch-generation} will
2901 not make a zeroth generation, so if a specified generation does not
2902 exist, the current generation will not be changed.
2904 @item --search-paths[=@var{kind}]
2905 @cindex search paths
2906 Report environment variable definitions, in Bash syntax, that may be
2907 needed in order to use the set of installed packages. These environment
2908 variables are used to specify @dfn{search paths} for files used by some
2909 of the installed packages.
2911 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2912 environment variables to be defined so it can look for headers and
2913 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2914 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2915 library are installed in the profile, then @code{--search-paths} will
2916 suggest setting these variables to @code{@var{profile}/include} and
2917 @code{@var{profile}/lib}, respectively.
2919 The typical use case is to define these environment variables in the
2923 $ eval `guix package --search-paths`
2926 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2927 meaning that the returned environment variable definitions will either
2928 be exact settings, or prefixes or suffixes of the current value of these
2929 variables. When omitted, @var{kind} defaults to @code{exact}.
2931 This option can also be used to compute the @emph{combined} search paths
2932 of several profiles. Consider this example:
2935 $ guix package -p foo -i guile
2936 $ guix package -p bar -i guile-json
2937 $ guix package -p foo -p bar --search-paths
2940 The last command above reports about the @code{GUILE_LOAD_PATH}
2941 variable, even though, taken individually, neither @file{foo} nor
2942 @file{bar} would lead to that recommendation.
2945 @item --profile=@var{profile}
2946 @itemx -p @var{profile}
2947 Use @var{profile} instead of the user's default profile.
2949 @var{profile} must be the name of a file that will be created upon
2950 completion. Concretely, @var{profile} will be a mere symbolic link
2951 (``symlink'') pointing to the actual profile where packages are
2955 $ guix install hello -p ~/code/my-profile
2957 $ ~/code/my-profile/bin/hello
2961 All it takes to get rid of the profile is to remove this symlink and its
2962 siblings that point to specific generations:
2965 $ rm ~/code/my-profile ~/code/my-profile-*-link
2968 @item --list-profiles
2969 List all the user's profiles:
2972 $ guix package --list-profiles
2973 /home/charlie/.guix-profile
2974 /home/charlie/code/my-profile
2975 /home/charlie/code/devel-profile
2976 /home/charlie/tmp/test
2979 When running as root, list all the profiles of all the users.
2981 @cindex collisions, in a profile
2982 @cindex colliding packages in profiles
2983 @cindex profile collisions
2984 @item --allow-collisions
2985 Allow colliding packages in the new profile. Use at your own risk!
2987 By default, @command{guix package} reports as an error @dfn{collisions}
2988 in the profile. Collisions happen when two or more different versions
2989 or variants of a given package end up in the profile.
2992 Use the bootstrap Guile to build the profile. This option is only
2993 useful to distribution developers.
2997 In addition to these actions, @command{guix package} supports the
2998 following options to query the current state of a profile, or the
2999 availability of packages:
3003 @item --search=@var{regexp}
3004 @itemx -s @var{regexp}
3005 @cindex searching for packages
3006 List the available packages whose name, synopsis, or description matches
3007 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3008 Print all the metadata of matching packages in
3009 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3010 GNU recutils manual}).
3012 This allows specific fields to be extracted using the @command{recsel}
3013 command, for instance:
3016 $ guix package -s malloc | recsel -p name,version,relevance
3030 Similarly, to show the name of all the packages available under the
3031 terms of the GNU@tie{}LGPL version 3:
3034 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3041 It is also possible to refine search results using several @code{-s} flags to
3042 @command{guix package}, or several arguments to @command{guix search}. For
3043 example, the following command returns a list of board games (this time using
3044 the @command{guix search} alias):
3047 $ guix search '\<board\>' game | recsel -p name
3052 If we were to omit @code{-s game}, we would also get software packages
3053 that deal with printed circuit boards; removing the angle brackets
3054 around @code{board} would further add packages that have to do with
3057 And now for a more elaborate example. The following command searches
3058 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3059 libraries, and prints the name and synopsis of the matching packages:
3062 $ guix search crypto library | \
3063 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3067 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3068 information on @dfn{selection expressions} for @code{recsel -e}.
3070 @item --show=@var{package}
3071 Show details about @var{package}, taken from the list of available packages, in
3072 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3076 $ guix package --show=python | recsel -p name,version
3084 You may also specify the full name of a package to only get details about a
3085 specific version of it (this time using the @command{guix show} alias):
3087 $ guix show python@@3.4 | recsel -p name,version
3094 @item --list-installed[=@var{regexp}]
3095 @itemx -I [@var{regexp}]
3096 List the currently installed packages in the specified profile, with the
3097 most recently installed packages shown last. When @var{regexp} is
3098 specified, list only installed packages whose name matches @var{regexp}.
3100 For each installed package, print the following items, separated by
3101 tabs: the package name, its version string, the part of the package that
3102 is installed (for instance, @code{out} for the default output,
3103 @code{include} for its headers, etc.), and the path of this package in
3106 @item --list-available[=@var{regexp}]
3107 @itemx -A [@var{regexp}]
3108 List packages currently available in the distribution for this system
3109 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3110 installed packages whose name matches @var{regexp}.
3112 For each package, print the following items separated by tabs: its name,
3113 its version string, the parts of the package (@pxref{Packages with
3114 Multiple Outputs}), and the source location of its definition.
3116 @item --list-generations[=@var{pattern}]
3117 @itemx -l [@var{pattern}]
3119 Return a list of generations along with their creation dates; for each
3120 generation, show the installed packages, with the most recently
3121 installed packages shown last. Note that the zeroth generation is never
3124 For each installed package, print the following items, separated by
3125 tabs: the name of a package, its version string, the part of the package
3126 that is installed (@pxref{Packages with Multiple Outputs}), and the
3127 location of this package in the store.
3129 When @var{pattern} is used, the command returns only matching
3130 generations. Valid patterns include:
3133 @item @emph{Integers and comma-separated integers}. Both patterns denote
3134 generation numbers. For instance, @code{--list-generations=1} returns
3137 And @code{--list-generations=1,8,2} outputs three generations in the
3138 specified order. Neither spaces nor trailing commas are allowed.
3140 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3141 specified generations and everything in between. Note that the start of
3142 a range must be smaller than its end.
3144 It is also possible to omit the endpoint. For example,
3145 @code{--list-generations=2..}, returns all generations starting from the
3148 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3149 or months by passing an integer along with the first letter of the
3150 duration. For example, @code{--list-generations=20d} lists generations
3151 that are up to 20 days old.
3154 @item --delete-generations[=@var{pattern}]
3155 @itemx -d [@var{pattern}]
3156 When @var{pattern} is omitted, delete all generations except the current
3159 This command accepts the same patterns as @option{--list-generations}.
3160 When @var{pattern} is specified, delete the matching generations. When
3161 @var{pattern} specifies a duration, generations @emph{older} than the
3162 specified duration match. For instance, @code{--delete-generations=1m}
3163 deletes generations that are more than one month old.
3165 If the current generation matches, it is @emph{not} deleted. Also, the
3166 zeroth generation is never deleted.
3168 Note that deleting generations prevents rolling back to them.
3169 Consequently, this command must be used with care.
3173 Finally, since @command{guix package} may actually start build
3174 processes, it supports all the common build options (@pxref{Common Build
3175 Options}). It also supports package transformation options, such as
3176 @option{--with-source} (@pxref{Package Transformation Options}).
3177 However, note that package transformations are lost when upgrading; to
3178 preserve transformations across upgrades, you should define your own
3179 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3180 (@pxref{Defining Packages}).
3183 @section Substitutes
3186 @cindex pre-built binaries
3187 Guix supports transparent source/binary deployment, which means that it
3188 can either build things locally, or download pre-built items from a
3189 server, or both. We call these pre-built items @dfn{substitutes}---they
3190 are substitutes for local build results. In many cases, downloading a
3191 substitute is much faster than building things locally.
3193 Substitutes can be anything resulting from a derivation build
3194 (@pxref{Derivations}). Of course, in the common case, they are
3195 pre-built package binaries, but source tarballs, for instance, which
3196 also result from derivation builds, can be available as substitutes.
3199 * Official Substitute Server:: One particular source of substitutes.
3200 * Substitute Server Authorization:: How to enable or disable substitutes.
3201 * Substitute Authentication:: How Guix verifies substitutes.
3202 * Proxy Settings:: How to get substitutes via proxy.
3203 * Substitution Failure:: What happens when substitution fails.
3204 * On Trusting Binaries:: How can you trust that binary blob?
3207 @node Official Substitute Server
3208 @subsection Official Substitute Server
3211 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3212 that builds packages from Guix continuously for some
3213 architectures, and makes them available as substitutes. This is the
3214 default source of substitutes; it can be overridden by passing the
3215 @option{--substitute-urls} option either to @command{guix-daemon}
3216 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3217 or to client tools such as @command{guix package}
3218 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3221 Substitute URLs can be either HTTP or HTTPS.
3222 HTTPS is recommended because communications are encrypted; conversely,
3223 using HTTP makes all communications visible to an eavesdropper, who
3224 could use the information gathered to determine, for instance, whether
3225 your system has unpatched security vulnerabilities.
3227 Substitutes from the official build farm are enabled by default when
3228 using Guix System (@pxref{GNU Distribution}). However,
3229 they are disabled by default when using Guix on a foreign distribution,
3230 unless you have explicitly enabled them via one of the recommended
3231 installation steps (@pxref{Installation}). The following paragraphs
3232 describe how to enable or disable substitutes for the official build
3233 farm; the same procedure can also be used to enable substitutes for any
3234 other substitute server.
3236 @node Substitute Server Authorization
3237 @subsection Substitute Server Authorization
3240 @cindex substitutes, authorization thereof
3241 @cindex access control list (ACL), for substitutes
3242 @cindex ACL (access control list), for substitutes
3243 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3245 must add its public key to the access control list (ACL) of archive
3246 imports, using the @command{guix archive} command (@pxref{Invoking guix
3247 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3248 be compromised and to serve genuine substitutes.
3250 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3251 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3252 the installation prefix of Guix. If you installed Guix from source,
3253 make sure you checked the GPG signature of
3254 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3255 Then, you can run something like this:
3258 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3261 Once this is in place, the output of a command like @code{guix build}
3262 should change from something like:
3265 $ guix build emacs --dry-run
3266 The following derivations would be built:
3267 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3268 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3269 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3270 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3278 $ guix build emacs --dry-run
3279 112.3 MB would be downloaded:
3280 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3281 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3282 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3283 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3288 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3289 will be downloaded, when possible, for future builds.
3291 @cindex substitutes, how to disable
3292 The substitute mechanism can be disabled globally by running
3293 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3294 guix-daemon}). It can also be disabled temporarily by passing the
3295 @code{--no-substitutes} option to @command{guix package}, @command{guix
3296 build}, and other command-line tools.
3298 @node Substitute Authentication
3299 @subsection Substitute Authentication
3301 @cindex digital signatures
3302 Guix detects and raises an error when attempting to use a substitute
3303 that has been tampered with. Likewise, it ignores substitutes that are
3304 not signed, or that are not signed by one of the keys listed in the ACL.
3306 There is one exception though: if an unauthorized server provides
3307 substitutes that are @emph{bit-for-bit identical} to those provided by
3308 an authorized server, then the unauthorized server becomes eligible for
3309 downloads. For example, assume we have chosen two substitute servers
3313 --substitute-urls="https://a.example.org https://b.example.org"
3317 @cindex reproducible builds
3318 If the ACL contains only the key for @code{b.example.org}, and if
3319 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3320 then Guix will download substitutes from @code{a.example.org} because it
3321 comes first in the list and can be considered a mirror of
3322 @code{b.example.org}. In practice, independent build machines usually
3323 produce the same binaries, thanks to bit-reproducible builds (see
3326 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3327 (in other words, the server is not authenticated), contrary to what
3328 HTTPS clients such as Web browsers usually do. This is because Guix
3329 authenticates substitute information itself, as explained above, which
3330 is what we care about (whereas X.509 certificates are about
3331 authenticating bindings between domain names and public keys.)
3333 @node Proxy Settings
3334 @subsection Proxy Settings
3337 Substitutes are downloaded over HTTP or HTTPS.
3338 The @code{http_proxy} environment
3339 variable can be set in the environment of @command{guix-daemon} and is
3340 honored for downloads of substitutes. Note that the value of
3341 @code{http_proxy} in the environment where @command{guix build},
3342 @command{guix package}, and other client commands are run has
3343 @emph{absolutely no effect}.
3345 @node Substitution Failure
3346 @subsection Substitution Failure
3348 Even when a substitute for a derivation is available, sometimes the
3349 substitution attempt will fail. This can happen for a variety of
3350 reasons: the substitute server might be offline, the substitute may
3351 recently have been deleted, the connection might have been interrupted,
3354 When substitutes are enabled and a substitute for a derivation is
3355 available, but the substitution attempt fails, Guix will attempt to
3356 build the derivation locally depending on whether or not
3357 @code{--fallback} was given (@pxref{fallback-option,, common build
3358 option @code{--fallback}}). Specifically, if @code{--fallback} was
3359 omitted, then no local build will be performed, and the derivation is
3360 considered to have failed. However, if @code{--fallback} was given,
3361 then Guix will attempt to build the derivation locally, and the success
3362 or failure of the derivation depends on the success or failure of the
3363 local build. Note that when substitutes are disabled or no substitute
3364 is available for the derivation in question, a local build will
3365 @emph{always} be performed, regardless of whether or not
3366 @code{--fallback} was given.
3368 To get an idea of how many substitutes are available right now, you can
3369 try running the @command{guix weather} command (@pxref{Invoking guix
3370 weather}). This command provides statistics on the substitutes provided
3373 @node On Trusting Binaries
3374 @subsection On Trusting Binaries
3376 @cindex trust, of pre-built binaries
3377 Today, each individual's control over their own computing is at the
3378 mercy of institutions, corporations, and groups with enough power and
3379 determination to subvert the computing infrastructure and exploit its
3380 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3381 convenient, we encourage users to also build on their own, or even run
3382 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3383 interesting target. One way to help is by publishing the software you
3384 build using @command{guix publish} so that others have one more choice
3385 of server to download substitutes from (@pxref{Invoking guix publish}).
3387 Guix has the foundations to maximize build reproducibility
3388 (@pxref{Features}). In most cases, independent builds of a given
3389 package or derivation should yield bit-identical results. Thus, through
3390 a diverse set of independent package builds, we can strengthen the
3391 integrity of our systems. The @command{guix challenge} command aims to
3392 help users assess substitute servers, and to assist developers in
3393 finding out about non-deterministic package builds (@pxref{Invoking guix
3394 challenge}). Similarly, the @option{--check} option of @command{guix
3395 build} allows users to check whether previously-installed substitutes
3396 are genuine by rebuilding them locally (@pxref{build-check,
3397 @command{guix build --check}}).
3399 In the future, we want Guix to have support to publish and retrieve
3400 binaries to/from other users, in a peer-to-peer fashion. If you would
3401 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3403 @node Packages with Multiple Outputs
3404 @section Packages with Multiple Outputs
3406 @cindex multiple-output packages
3407 @cindex package outputs
3410 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3411 source package leads to exactly one directory in the store. When running
3412 @command{guix install glibc}, one installs the default output of the
3413 GNU libc package; the default output is called @code{out}, but its name
3414 can be omitted as shown in this command. In this particular case, the
3415 default output of @code{glibc} contains all the C header files, shared
3416 libraries, static libraries, Info documentation, and other supporting
3419 Sometimes it is more appropriate to separate the various types of files
3420 produced from a single source package into separate outputs. For
3421 instance, the GLib C library (used by GTK+ and related packages)
3422 installs more than 20 MiB of reference documentation as HTML pages.
3423 To save space for users who do not need it, the documentation goes to a
3424 separate output, called @code{doc}. To install the main GLib output,
3425 which contains everything but the documentation, one would run:
3431 @cindex documentation
3432 The command to install its documentation is:
3435 guix install glib:doc
3438 Some packages install programs with different ``dependency footprints''.
3439 For instance, the WordNet package installs both command-line tools and
3440 graphical user interfaces (GUIs). The former depend solely on the C
3441 library, whereas the latter depend on Tcl/Tk and the underlying X
3442 libraries. In this case, we leave the command-line tools in the default
3443 output, whereas the GUIs are in a separate output. This allows users
3444 who do not need the GUIs to save space. The @command{guix size} command
3445 can help find out about such situations (@pxref{Invoking guix size}).
3446 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3448 There are several such multiple-output packages in the GNU distribution.
3449 Other conventional output names include @code{lib} for libraries and
3450 possibly header files, @code{bin} for stand-alone programs, and
3451 @code{debug} for debugging information (@pxref{Installing Debugging
3452 Files}). The outputs of a packages are listed in the third column of
3453 the output of @command{guix package --list-available} (@pxref{Invoking
3457 @node Invoking guix gc
3458 @section Invoking @command{guix gc}
3460 @cindex garbage collector
3462 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3463 The @command{guix gc} command allows users to explicitly run the garbage
3464 collector to reclaim space from the @file{/gnu/store} directory. It is
3465 the @emph{only} way to remove files from @file{/gnu/store}---removing
3466 files or directories manually may break it beyond repair!
3469 @cindex garbage collector roots
3470 The garbage collector has a set of known @dfn{roots}: any file under
3471 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3472 cannot be deleted; any other file is considered @dfn{dead} and may be
3473 deleted. The set of garbage collector roots (``GC roots'' for short)
3474 includes default user profiles; by default, the symlinks under
3475 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3476 added with @command{guix build --root}, for example (@pxref{Invoking
3477 guix build}). The @command{guix gc --list-roots} command lists them.
3479 Prior to running @code{guix gc --collect-garbage} to make space, it is
3480 often useful to remove old generations from user profiles; that way, old
3481 package builds referenced by those generations can be reclaimed. This
3482 is achieved by running @code{guix package --delete-generations}
3483 (@pxref{Invoking guix package}).
3485 Our recommendation is to run a garbage collection periodically, or when
3486 you are short on disk space. For instance, to guarantee that at least
3487 5@tie{}GB are available on your disk, simply run:
3493 It is perfectly safe to run as a non-interactive periodic job
3494 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3495 Running @command{guix gc} with no arguments will collect as
3496 much garbage as it can, but that is often inconvenient: you may find
3497 yourself having to rebuild or re-download software that is ``dead'' from
3498 the GC viewpoint but that is necessary to build other pieces of
3499 software---e.g., the compiler tool chain.
3501 The @command{guix gc} command has three modes of operation: it can be
3502 used to garbage-collect any dead files (the default), to delete specific
3503 files (the @code{--delete} option), to print garbage-collector
3504 information, or for more advanced queries. The garbage collection
3505 options are as follows:
3508 @item --collect-garbage[=@var{min}]
3509 @itemx -C [@var{min}]
3510 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3511 sub-directories. This is the default operation when no option is
3514 When @var{min} is given, stop once @var{min} bytes have been collected.
3515 @var{min} may be a number of bytes, or it may include a unit as a
3516 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3517 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3519 When @var{min} is omitted, collect all the garbage.
3521 @item --free-space=@var{free}
3522 @itemx -F @var{free}
3523 Collect garbage until @var{free} space is available under
3524 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3525 as @code{500MiB}, as described above.
3527 When @var{free} or more is already available in @file{/gnu/store}, do
3528 nothing and exit immediately.
3530 @item --delete-generations[=@var{duration}]
3531 @itemx -d [@var{duration}]
3532 Before starting the garbage collection process, delete all the generations
3533 older than @var{duration}, for all the user profiles; when run as root, this
3534 applies to all the profiles @emph{of all the users}.
3536 For example, this command deletes all the generations of all your profiles
3537 that are older than 2 months (except generations that are current), and then
3538 proceeds to free space until at least 10 GiB are available:
3541 guix gc -d 2m -F 10G
3546 Attempt to delete all the store files and directories specified as
3547 arguments. This fails if some of the files are not in the store, or if
3548 they are still live.
3550 @item --list-failures
3551 List store items corresponding to cached build failures.
3553 This prints nothing unless the daemon was started with
3554 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3555 @option{--cache-failures}}).
3558 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3562 List store items in use by currently running processes. These store
3563 items are effectively considered GC roots: they cannot be deleted.
3565 @item --clear-failures
3566 Remove the specified store items from the failed-build cache.
3568 Again, this option only makes sense when the daemon is started with
3569 @option{--cache-failures}. Otherwise, it does nothing.
3572 Show the list of dead files and directories still present in the
3573 store---i.e., files and directories no longer reachable from any root.
3576 Show the list of live store files and directories.
3580 In addition, the references among existing store files can be queried:
3586 @cindex package dependencies
3587 List the references (respectively, the referrers) of store files given
3593 List the requisites of the store files passed as arguments. Requisites
3594 include the store files themselves, their references, and the references
3595 of these, recursively. In other words, the returned list is the
3596 @dfn{transitive closure} of the store files.
3598 @xref{Invoking guix size}, for a tool to profile the size of the closure
3599 of an element. @xref{Invoking guix graph}, for a tool to visualize
3600 the graph of references.
3604 Return the derivation(s) leading to the given store items
3605 (@pxref{Derivations}).
3607 For example, this command:
3610 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3614 returns the @file{.drv} file(s) leading to the @code{emacs} package
3615 installed in your profile.
3617 Note that there may be zero matching @file{.drv} files, for instance
3618 because these files have been garbage-collected. There can also be more
3619 than one matching @file{.drv} due to fixed-output derivations.
3622 Lastly, the following options allow you to check the integrity of the
3623 store and to control disk usage.
3627 @item --verify[=@var{options}]
3628 @cindex integrity, of the store
3629 @cindex integrity checking
3630 Verify the integrity of the store.
3632 By default, make sure that all the store items marked as valid in the
3633 database of the daemon actually exist in @file{/gnu/store}.
3635 When provided, @var{options} must be a comma-separated list containing one
3636 or more of @code{contents} and @code{repair}.
3638 When passing @option{--verify=contents}, the daemon computes the
3639 content hash of each store item and compares it against its hash in the
3640 database. Hash mismatches are reported as data corruptions. Because it
3641 traverses @emph{all the files in the store}, this command can take a
3642 long time, especially on systems with a slow disk drive.
3644 @cindex repairing the store
3645 @cindex corruption, recovering from
3646 Using @option{--verify=repair} or @option{--verify=contents,repair}
3647 causes the daemon to try to repair corrupt store items by fetching
3648 substitutes for them (@pxref{Substitutes}). Because repairing is not
3649 atomic, and thus potentially dangerous, it is available only to the
3650 system administrator. A lightweight alternative, when you know exactly
3651 which items in the store are corrupt, is @command{guix build --repair}
3652 (@pxref{Invoking guix build}).
3655 @cindex deduplication
3656 Optimize the store by hard-linking identical files---this is
3657 @dfn{deduplication}.
3659 The daemon performs deduplication after each successful build or archive
3660 import, unless it was started with @code{--disable-deduplication}
3661 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3662 this option is primarily useful when the daemon was running with
3663 @code{--disable-deduplication}.
3667 @node Invoking guix pull
3668 @section Invoking @command{guix pull}
3670 @cindex upgrading Guix
3671 @cindex updating Guix
3672 @cindex @command{guix pull}
3674 Packages are installed or upgraded to the latest version available in
3675 the distribution currently available on your local machine. To update
3676 that distribution, along with the Guix tools, you must run @command{guix
3677 pull}: the command downloads the latest Guix source code and package
3678 descriptions, and deploys it. Source code is downloaded from a
3679 @uref{https://git-scm.com, Git} repository, by default the official
3680 GNU@tie{}Guix repository, though this can be customized.
3682 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3683 (@pxref{Channels}) specified by one of the followings, in this order:
3687 the @option{--channels} option;
3689 the user's @file{~/.config/guix/channels.scm} file;
3691 the system-wide @file{/etc/guix/channels.scm} file;
3693 the built-in default channels specified in the @code{%default-channels}
3697 On completion, @command{guix package} will use packages and package
3698 versions from this just-retrieved copy of Guix. Not only that, but all
3699 the Guix commands and Scheme modules will also be taken from that latest
3700 version. New @command{guix} sub-commands added by the update also
3703 Any user can update their Guix copy using @command{guix pull}, and the
3704 effect is limited to the user who ran @command{guix pull}. For
3705 instance, when user @code{root} runs @command{guix pull}, this has no
3706 effect on the version of Guix that user @code{alice} sees, and vice
3709 The result of running @command{guix pull} is a @dfn{profile} available
3710 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3711 make sure to add it to the beginning of your search path so that you use
3712 the latest version, and similarly for the Info manual
3713 (@pxref{Documentation}):
3716 export PATH="$HOME/.config/guix/current/bin:$PATH"
3717 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3720 The @code{--list-generations} or @code{-l} option lists past generations
3721 produced by @command{guix pull}, along with details about their provenance:
3725 Generation 1 Jun 10 2018 00:18:18
3727 repository URL: https://git.savannah.gnu.org/git/guix.git
3728 branch: origin/master
3729 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3731 Generation 2 Jun 11 2018 11:02:49
3733 repository URL: https://git.savannah.gnu.org/git/guix.git
3734 branch: origin/master
3735 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3736 2 new packages: keepalived, libnfnetlink
3737 6 packages upgraded: emacs-nix-mode@@2.0.4,
3738 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3739 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3741 Generation 3 Jun 13 2018 23:31:07 (current)
3743 repository URL: https://git.savannah.gnu.org/git/guix.git
3744 branch: origin/master
3745 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3746 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3747 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3750 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3751 describe the current status of Guix.
3753 This @code{~/.config/guix/current} profile works exactly like the profiles
3754 created by @command{guix package} (@pxref{Invoking guix package}). That
3755 is, you can list generations, roll back to the previous
3756 generation---i.e., the previous Guix---and so on:
3759 $ guix pull --roll-back
3760 switched from generation 3 to 2
3761 $ guix pull --delete-generations=1
3762 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3765 You can also use @command{guix package} (@pxref{Invoking guix package})
3766 to manage the profile by naming it explicitly:
3768 $ guix package -p ~/.config/guix/current --roll-back
3769 switched from generation 3 to 2
3770 $ guix package -p ~/.config/guix/current --delete-generations=1
3771 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3774 The @command{guix pull} command is usually invoked with no arguments,
3775 but it supports the following options:
3778 @item --url=@var{url}
3779 @itemx --commit=@var{commit}
3780 @itemx --branch=@var{branch}
3781 Download code for the @code{guix} channel from the specified @var{url}, at the
3782 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3783 string), or @var{branch}.
3785 @cindex @file{channels.scm}, configuration file
3786 @cindex configuration file for channels
3787 These options are provided for convenience, but you can also specify your
3788 configuration in the @file{~/.config/guix/channels.scm} file or using the
3789 @option{--channels} option (see below).
3791 @item --channels=@var{file}
3792 @itemx -C @var{file}
3793 Read the list of channels from @var{file} instead of
3794 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3795 @var{file} must contain Scheme code that
3796 evaluates to a list of channel objects. @xref{Channels}, for more
3799 @cindex channel news
3802 Display the list of packages added or upgraded since the previous
3803 generation, as well as, occasionally, news written by channel authors
3804 for their users (@pxref{Channels, Writing Channel News}).
3806 The package information is the same as displayed upon @command{guix
3807 pull} completion, but without ellipses; it is also similar to the output
3808 of @command{guix pull -l} for the last generation (see below).
3810 @item --list-generations[=@var{pattern}]
3811 @itemx -l [@var{pattern}]
3812 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3813 is provided, the subset of generations that match @var{pattern}.
3814 The syntax of @var{pattern} is the same as with @code{guix package
3815 --list-generations} (@pxref{Invoking guix package}).
3818 @cindex rolling back
3819 @cindex undoing transactions
3820 @cindex transactions, undoing
3821 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3822 undo the last transaction.
3824 @item --switch-generation=@var{pattern}
3825 @itemx -S @var{pattern}
3827 Switch to a particular generation defined by @var{pattern}.
3829 @var{pattern} may be either a generation number or a number prefixed
3830 with ``+'' or ``-''. The latter means: move forward/backward by a
3831 specified number of generations. For example, if you want to return to
3832 the latest generation after @code{--roll-back}, use
3833 @code{--switch-generation=+1}.
3835 @item --delete-generations[=@var{pattern}]
3836 @itemx -d [@var{pattern}]
3837 When @var{pattern} is omitted, delete all generations except the current
3840 This command accepts the same patterns as @option{--list-generations}.
3841 When @var{pattern} is specified, delete the matching generations. When
3842 @var{pattern} specifies a duration, generations @emph{older} than the
3843 specified duration match. For instance, @code{--delete-generations=1m}
3844 deletes generations that are more than one month old.
3846 If the current generation matches, it is @emph{not} deleted.
3848 Note that deleting generations prevents rolling back to them.
3849 Consequently, this command must be used with care.
3851 @xref{Invoking guix describe}, for a way to display information about the
3852 current generation only.
3854 @item --profile=@var{profile}
3855 @itemx -p @var{profile}
3856 Use @var{profile} instead of @file{~/.config/guix/current}.
3860 Show which channel commit(s) would be used and what would be built or
3861 substituted but do not actually do it.
3863 @item --system=@var{system}
3864 @itemx -s @var{system}
3865 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3866 the system type of the build host.
3869 Produce verbose output, writing build logs to the standard error output.
3872 Use the bootstrap Guile to build the latest Guix. This option is only
3873 useful to Guix developers.
3876 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3877 repository and branch to pull from, as well as @emph{additional} repositories
3878 containing package modules that should be deployed. @xref{Channels}, for more
3881 In addition, @command{guix pull} supports all the common build options
3882 (@pxref{Common Build Options}).
3888 @cindex @file{channels.scm}, configuration file
3889 @cindex configuration file for channels
3890 @cindex @command{guix pull}, configuration file
3891 @cindex configuration of @command{guix pull}
3892 Guix and its package collection are updated by running @command{guix pull}
3893 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3894 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3895 customized by defining @dfn{channels} in the
3896 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3897 of a Git repository to be deployed, and @command{guix pull} can be instructed
3898 to pull from one or more channels. In other words, channels can be used to
3899 @emph{customize} and to @emph{extend} Guix, as we will see below.
3901 @subsection Using a Custom Guix Channel
3903 The channel called @code{guix} specifies where Guix itself---its command-line
3904 tools as well as its package collection---should be downloaded. For instance,
3905 suppose you want to update from your own copy of the Guix repository at
3906 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3907 write in @code{~/.config/guix/channels.scm} this specification:
3910 ;; Tell 'guix pull' to use my own repo.
3913 (url "https://example.org/my-guix.git")
3914 (branch "super-hacks")))
3918 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3919 branch of the repository at @code{example.org}.
3921 @subsection Specifying Additional Channels
3923 @cindex extending the package collection (channels)
3924 @cindex personal packages (channels)
3925 @cindex channels, for personal packages
3926 You can also specify @emph{additional channels} to pull from. Let's say you
3927 have a bunch of custom package variants or personal packages that you think
3928 would make little sense to contribute to the Guix project, but would like to
3929 have these packages transparently available to you at the command line. You
3930 would first write modules containing those package definitions (@pxref{Package
3931 Modules}), maintain them in a Git repository, and then you and anyone else can
3932 use it as an additional channel to get packages from. Neat, no?
3934 @c What follows stems from discussions at
3935 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3936 @c earlier discussions on guix-devel@gnu.org.
3938 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3939 publish your personal channel to the world, we would like to share a few words
3944 Before publishing a channel, please consider contributing your package
3945 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3946 to free software of all sorts, and packages in Guix proper are readily
3947 available to all Guix users and benefit from the project's quality assurance
3951 When you maintain package definitions outside Guix, we, Guix developers,
3952 consider that @emph{the compatibility burden is on you}. Remember that
3953 package modules and package definitions are just Scheme code that uses various
3954 programming interfaces (APIs). We want to remain free to change these APIs to
3955 keep improving Guix, possibly in ways that break your channel. We never
3956 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3960 Corollary: if you're using an external channel and that channel breaks, please
3961 @emph{report the issue to the channel authors}, not to the Guix project.
3964 You've been warned! Having said this, we believe external channels are a
3965 practical way to exert your freedom to augment Guix' package collection and to
3966 share your improvements, which are basic tenets of
3967 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3968 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3971 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3972 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3975 @vindex %default-channels
3977 ;; Add my personal packages to those Guix provides.
3979 (name 'my-personal-packages)
3980 (url "https://example.org/personal-packages.git"))
3985 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3986 add a channel the list of channels that the variable @code{%default-channels}
3987 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3988 Manual}). With this file in place, @command{guix pull} builds not only Guix
3989 but also the package modules from your own repository. The result in
3990 @file{~/.config/guix/current} is the union of Guix with your own package
3994 $ guix pull --list-generations
3996 Generation 19 Aug 27 2018 16:20:48
3998 repository URL: https://git.savannah.gnu.org/git/guix.git
4000 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4001 my-personal-packages dd3df5e
4002 repository URL: https://example.org/personal-packages.git
4004 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4005 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4006 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4010 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4011 both Guix and packages from the @code{my-personal-packages} channel. Among
4012 the new and upgraded packages that are listed, some like @code{my-gimp} and
4013 @code{my-emacs-with-cool-features} might come from
4014 @code{my-personal-packages}, while others come from the Guix default channel.
4016 To create a channel, create a Git repository containing your own package
4017 modules and make it available. The repository can contain anything, but a
4018 useful channel will contain Guile modules that export packages. Once you
4019 start using a channel, Guix will behave as if the root directory of that
4020 channel's Git repository has been added to the Guile load path (@pxref{Load
4021 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4022 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4023 module, then the module will be available under the name @code{(my-packages
4024 my-tools)}, and you will be able to use it like any other module
4025 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4027 @cindex dependencies, channels
4028 @cindex meta-data, channels
4029 @subsection Declaring Channel Dependencies
4031 Channel authors may decide to augment a package collection provided by other
4032 channels. They can declare their channel to be dependent on other channels in
4033 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4034 the channel repository.
4036 The meta-data file should contain a simple S-expression like this:
4043 (name some-collection)
4044 (url "https://example.org/first-collection.git"))
4046 (name some-other-collection)
4047 (url "https://example.org/second-collection.git")
4048 (branch "testing"))))
4051 In the above example this channel is declared to depend on two other channels,
4052 which will both be fetched automatically. The modules provided by the channel
4053 will be compiled in an environment where the modules of all these declared
4054 channels are available.
4056 For the sake of reliability and maintainability, you should avoid dependencies
4057 on channels that you don't control, and you should aim to keep the number of
4058 dependencies to a minimum.
4060 @cindex subdirectory, channels
4061 @subsection Package Modules in a Sub-directory
4063 As a channel author, you may want to keep your channel modules in a
4064 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4065 add a meta-data file @file{.guix-channel} that contains:
4073 @cindex news, for channels
4074 @subsection Writing Channel News
4076 Channel authors may occasionally want to communicate to their users
4077 information about important changes in the channel. You'd send them all
4078 an email, but that's not convenient.
4080 Instead, channels can provide a @dfn{news file}; when the channel users
4081 run @command{guix pull}, that news file is automatically read and
4082 @command{guix pull --news} can display the announcements that correspond
4083 to the new commits that have been pulled, if any.
4085 To do that, channel authors must first declare the name of the news file
4086 in their @file{.guix-channel} file:
4091 (news-file "etc/news.txt"))
4094 The news file itself, @file{etc/news.txt} in this example, must look
4095 something like this:
4100 (entry (tag "the-bug-fix")
4101 (title (en "Fixed terrible bug")
4103 (body (en "@@emph@{Good news@}! It's fixed!")
4104 (eo "Certe ĝi pli bone funkcias nun!")))
4105 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4106 (title (en "Added a great package")
4107 (ca "Què vol dir guix?"))
4108 (body (en "Don't miss the @@code@{hello@} package!"))))
4111 The file consists of a list of @dfn{news entries}. Each entry is
4112 associated with a commit or tag: it describes changes made in this
4113 commit, possibly in preceding commits as well. Users see entries only
4114 the first time they obtain the commit the entry refers to.
4116 The @code{title} field should be a one-line summary while @code{body}
4117 can be arbitrarily long, and both can contain Texinfo markup
4118 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4119 a list of language tag/message tuples, which allows @command{guix pull}
4120 to display news in the language that corresponds to the user's locale.
4122 If you want to translate news using a gettext-based workflow, you can
4123 extract translatable strings with @command{xgettext} (@pxref{xgettext
4124 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4125 you write news entries in English first, the command below creates a PO
4126 file containing the strings to translate:
4129 xgettext -o news.po -l scheme -ken etc/news.scm
4132 To sum up, yes, you could use your channel as a blog. But beware, this
4133 is @emph{not quite} what your users might expect.
4135 @subsection Replicating Guix
4137 @cindex pinning, channels
4138 @cindex replicating Guix
4139 @cindex reproducibility, of Guix
4140 The @command{guix pull --list-generations} output above shows precisely which
4141 commits were used to build this instance of Guix. We can thus replicate it,
4142 say, on another machine, by providing a channel specification in
4143 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4146 ;; Deploy specific commits of my channels of interest.
4149 (url "https://git.savannah.gnu.org/git/guix.git")
4150 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4152 (name 'my-personal-packages)
4153 (url "https://example.org/personal-packages.git")
4154 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4157 The @command{guix describe --format=channels} command can even generate this
4158 list of channels directly (@pxref{Invoking guix describe}). The resulting
4159 file can be used with the -C options of @command{guix pull}
4160 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4161 (@pxref{Invoking guix time-machine}).
4163 At this point the two machines run the @emph{exact same Guix}, with access to
4164 the @emph{exact same packages}. The output of @command{guix build gimp} on
4165 one machine will be exactly the same, bit for bit, as the output of the same
4166 command on the other machine. It also means both machines have access to all
4167 the source code of Guix and, transitively, to all the source code of every
4170 This gives you super powers, allowing you to track the provenance of binary
4171 artifacts with very fine grain, and to reproduce software environments at
4172 will---some sort of ``meta reproducibility'' capabilities, if you will.
4173 @xref{Inferiors}, for another way to take advantage of these super powers.
4175 @node Invoking guix time-machine
4176 @section Invoking @command{guix time-machine}
4178 @cindex @command{guix time-machine}
4179 @cindex pinning, channels
4180 @cindex replicating Guix
4181 @cindex reproducibility, of Guix
4183 The @command{guix time-machine} command provides access to other
4184 revisions of Guix, for example to install older versions of packages,
4185 or to reproduce a computation in an identical environment. The revision
4186 of Guix to be used is defined by a commit or by a channel
4187 description file created by @command{guix describe}
4188 (@pxref{Invoking guix describe}).
4190 The general syntax is:
4193 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4196 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4197 @command{guix} command if the specified revision. The @var{options} that define
4198 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4201 @item --url=@var{url}
4202 @itemx --commit=@var{commit}
4203 @itemx --branch=@var{branch}
4204 Use the @code{guix} channel from the specified @var{url}, at the
4205 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4206 string), or @var{branch}.
4208 @item --channels=@var{file}
4209 @itemx -C @var{file}
4210 Read the list of channels from @var{file}. @var{file} must contain
4211 Scheme code that evaluates to a list of channel objects.
4212 @xref{Channels} for more information.
4215 As for @command{guix pull}, the absence of any options means that the
4216 the latest commit on the master branch will be used. The command
4219 guix time-machine -- build hello
4222 will thus build the package @code{hello} as defined in the master branch,
4223 which is in general a newer revison of Guix than you have installed.
4224 Time travel works in both directions!
4226 Note that @command{guix time-machine} can trigger builds of channels and
4227 their dependencies, and these are controlled by the standard build
4228 options (@pxref{Common Build Options}).
4233 @c TODO: Remove this once we're more confident about API stability.
4235 The functionality described here is a ``technology preview'' as of version
4236 @value{VERSION}. As such, the interface is subject to change.
4240 @cindex composition of Guix revisions
4241 Sometimes you might need to mix packages from the revision of Guix you're
4242 currently running with packages available in a different revision of Guix.
4243 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4244 revisions in arbitrary ways.
4246 @cindex inferior packages
4247 Technically, an ``inferior'' is essentially a separate Guix process connected
4248 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4249 @code{(guix inferior)} module allows you to create inferiors and to
4250 communicate with them. It also provides a high-level interface to browse and
4251 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4253 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4254 to interact with a separate revision of Guix. For example, let's assume you
4255 want to install in your profile the current @code{guile} package, along with
4256 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4257 because the newer @code{guile-json} has an incompatible API and you want to
4258 run your code against the old API@. To do that, you could write a manifest for
4259 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4260 manifest, you would create an inferior for that old Guix revision you care
4261 about, and you would look up the @code{guile-json} package in the inferior:
4264 (use-modules (guix inferior) (guix channels)
4265 (srfi srfi-1)) ;for 'first'
4268 ;; This is the old revision from which we want to
4269 ;; extract guile-json.
4272 (url "https://git.savannah.gnu.org/git/guix.git")
4274 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4277 ;; An inferior representing the above revision.
4278 (inferior-for-channels channels))
4280 ;; Now create a manifest with the current "guile" package
4281 ;; and the old "guile-json" package.
4283 (list (first (lookup-inferior-packages inferior "guile-json"))
4284 (specification->package "guile")))
4287 On its first run, @command{guix package --manifest} might have to build the
4288 channel you specified before it can create the inferior; subsequent runs will
4289 be much faster because the Guix revision will be cached.
4291 The @code{(guix inferior)} module provides the following procedures to open an
4294 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4295 [#:cache-directory] [#:ttl]
4296 Return an inferior for @var{channels}, a list of channels. Use the cache at
4297 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4298 This procedure opens a new connection to the build daemon.
4300 As a side effect, this procedure may build or substitute binaries for
4301 @var{channels}, which can take time.
4304 @deffn {Scheme Procedure} open-inferior @var{directory} @
4305 [#:command "bin/guix"]
4306 Open the inferior Guix in @var{directory}, running
4307 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4308 the inferior could not be launched.
4311 @cindex inferior packages
4312 The procedures listed below allow you to obtain and manipulate inferior
4315 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4316 Return the list of packages known to @var{inferior}.
4319 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4321 Return the sorted list of inferior packages matching @var{name} in
4322 @var{inferior}, with highest version numbers first. If @var{version} is true,
4323 return only packages with a version number prefixed by @var{version}.
4326 @deffn {Scheme Procedure} inferior-package? @var{obj}
4327 Return true if @var{obj} is an inferior package.
4330 @deffn {Scheme Procedure} inferior-package-name @var{package}
4331 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4332 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4333 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4334 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4335 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4336 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4337 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4338 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4339 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4340 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4341 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4342 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4343 These procedures are the counterpart of package record accessors
4344 (@pxref{package Reference}). Most of them work by querying the inferior
4345 @var{package} comes from, so the inferior must still be live when you call
4349 Inferior packages can be used transparently like any other package or
4350 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4351 transparently handled by the @code{packages->manifest} procedure, which is
4352 commonly use in manifests (@pxref{Invoking guix package, the
4353 @option{--manifest} option of @command{guix package}}). Thus you can insert
4354 an inferior package pretty much anywhere you would insert a regular package:
4355 in manifests, in the @code{packages} field of your @code{operating-system}
4356 declaration, and so on.
4358 @node Invoking guix describe
4359 @section Invoking @command{guix describe}
4361 @cindex reproducibility
4362 @cindex replicating Guix
4363 Often you may want to answer questions like: ``Which revision of Guix am I
4364 using?'' or ``Which channels am I using?'' This is useful information in many
4365 situations: if you want to @emph{replicate} an environment on a different
4366 machine or user account, if you want to report a bug or to determine what
4367 change in the channels you are using caused it, or if you want to record your
4368 system state for reproducibility purposes. The @command{guix describe}
4369 command answers these questions.
4371 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4372 displays the channel(s) that it was built from, including their repository URL
4373 and commit IDs (@pxref{Channels}):
4377 Generation 10 Sep 03 2018 17:32:44 (current)
4379 repository URL: https://git.savannah.gnu.org/git/guix.git
4381 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4384 If you're familiar with the Git version control system, this is similar in
4385 spirit to @command{git describe}; the output is also similar to that of
4386 @command{guix pull --list-generations}, but limited to the current generation
4387 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4388 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4389 information is all it takes to describe the revision of Guix you're using, and
4390 also to replicate it.
4392 To make it easier to replicate Guix, @command{guix describe} can also be asked
4393 to return a list of channels instead of the human-readable description above:
4396 $ guix describe -f channels
4399 (url "https://git.savannah.gnu.org/git/guix.git")
4401 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4405 You can save this to a file and feed it to @command{guix pull -C} on some
4406 other machine or at a later point in time, which will instantiate @emph{this
4407 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4408 From there on, since you're able to deploy the same revision of Guix, you can
4409 just as well @emph{replicate a complete software environment}. We humbly
4410 think that this is @emph{awesome}, and we hope you'll like it too!
4412 The details of the options supported by @command{guix describe} are as
4416 @item --format=@var{format}
4417 @itemx -f @var{format}
4418 Produce output in the specified @var{format}, one of:
4422 produce human-readable output;
4424 produce a list of channel specifications that can be passed to @command{guix
4425 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4429 produce a list of channel specifications in JSON format;
4431 produce a list of channel specifications in Recutils format.
4434 @item --profile=@var{profile}
4435 @itemx -p @var{profile}
4436 Display information about @var{profile}.
4439 @node Invoking guix archive
4440 @section Invoking @command{guix archive}
4442 @cindex @command{guix archive}
4444 The @command{guix archive} command allows users to @dfn{export} files
4445 from the store into a single archive, and to later @dfn{import} them on
4446 a machine that runs Guix.
4447 In particular, it allows store files to be transferred from one machine
4448 to the store on another machine.
4451 If you're looking for a way to produce archives in a format suitable for
4452 tools other than Guix, @pxref{Invoking guix pack}.
4455 @cindex exporting store items
4456 To export store files as an archive to standard output, run:
4459 guix archive --export @var{options} @var{specifications}...
4462 @var{specifications} may be either store file names or package
4463 specifications, as for @command{guix package} (@pxref{Invoking guix
4464 package}). For instance, the following command creates an archive
4465 containing the @code{gui} output of the @code{git} package and the main
4466 output of @code{emacs}:
4469 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4472 If the specified packages are not built yet, @command{guix archive}
4473 automatically builds them. The build process may be controlled with the
4474 common build options (@pxref{Common Build Options}).
4476 To transfer the @code{emacs} package to a machine connected over SSH,
4480 guix archive --export -r emacs | ssh the-machine guix archive --import
4484 Similarly, a complete user profile may be transferred from one machine
4485 to another like this:
4488 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4489 ssh the-machine guix archive --import
4493 However, note that, in both examples, all of @code{emacs} and the
4494 profile as well as all of their dependencies are transferred (due to
4495 @code{-r}), regardless of what is already available in the store on the
4496 target machine. The @code{--missing} option can help figure out which
4497 items are missing from the target store. The @command{guix copy}
4498 command simplifies and optimizes this whole process, so this is probably
4499 what you should use in this case (@pxref{Invoking guix copy}).
4501 @cindex nar, archive format
4502 @cindex normalized archive (nar)
4503 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4504 comparable in spirit to `tar', but with differences
4505 that make it more appropriate for our purposes. First, rather than
4506 recording all Unix metadata for each file, the nar format only mentions
4507 the file type (regular, directory, or symbolic link); Unix permissions
4508 and owner/group are dismissed. Second, the order in which directory
4509 entries are stored always follows the order of file names according to
4510 the C locale collation order. This makes archive production fully
4513 When exporting, the daemon digitally signs the contents of the archive,
4514 and that digital signature is appended. When importing, the daemon
4515 verifies the signature and rejects the import in case of an invalid
4516 signature or if the signing key is not authorized.
4517 @c FIXME: Add xref to daemon doc about signatures.
4519 The main options are:
4523 Export the specified store files or packages (see below.) Write the
4524 resulting archive to the standard output.
4526 Dependencies are @emph{not} included in the output, unless
4527 @code{--recursive} is passed.
4531 When combined with @code{--export}, this instructs @command{guix
4532 archive} to include dependencies of the given items in the archive.
4533 Thus, the resulting archive is self-contained: it contains the closure
4534 of the exported store items.
4537 Read an archive from the standard input, and import the files listed
4538 therein into the store. Abort if the archive has an invalid digital
4539 signature, or if it is signed by a public key not among the authorized
4540 keys (see @code{--authorize} below.)
4543 Read a list of store file names from the standard input, one per line,
4544 and write on the standard output the subset of these files missing from
4547 @item --generate-key[=@var{parameters}]
4548 @cindex signing, archives
4549 Generate a new key pair for the daemon. This is a prerequisite before
4550 archives can be exported with @code{--export}. Note that this operation
4551 usually takes time, because it needs to gather enough entropy to
4552 generate the key pair.
4554 The generated key pair is typically stored under @file{/etc/guix}, in
4555 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4556 key, which must be kept secret.) When @var{parameters} is omitted,
4557 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4558 versions before 1.6.0, it is a 4096-bit RSA key.
4559 Alternatively, @var{parameters} can specify
4560 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4561 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4562 Libgcrypt Reference Manual}).
4565 @cindex authorizing, archives
4566 Authorize imports signed by the public key passed on standard input.
4567 The public key must be in ``s-expression advanced format''---i.e., the
4568 same format as the @file{signing-key.pub} file.
4570 The list of authorized keys is kept in the human-editable file
4571 @file{/etc/guix/acl}. The file contains
4572 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4573 s-expressions''} and is structured as an access-control list in the
4574 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4577 @item --extract=@var{directory}
4578 @itemx -x @var{directory}
4579 Read a single-item archive as served by substitute servers
4580 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4581 low-level operation needed in only very narrow use cases; see below.
4583 For example, the following command extracts the substitute for Emacs
4584 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4588 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4589 | bunzip2 | guix archive -x /tmp/emacs
4592 Single-item archives are different from multiple-item archives produced
4593 by @command{guix archive --export}; they contain a single store item,
4594 and they do @emph{not} embed a signature. Thus this operation does
4595 @emph{no} signature verification and its output should be considered
4598 The primary purpose of this operation is to facilitate inspection of
4599 archive contents coming from possibly untrusted substitute servers.
4604 @c *********************************************************************
4606 @chapter Development
4608 @cindex software development
4609 If you are a software developer, Guix provides tools that you should find
4610 helpful---independently of the language you're developing in. This is what
4611 this chapter is about.
4613 The @command{guix environment} command provides a convenient way to set up
4614 @dfn{development environments} containing all the dependencies and tools
4615 necessary to work on the software package of your choice. The @command{guix
4616 pack} command allows you to create @dfn{application bundles} that can be
4617 easily distributed to users who do not run Guix.
4620 * Invoking guix environment:: Setting up development environments.
4621 * Invoking guix pack:: Creating software bundles.
4624 @node Invoking guix environment
4625 @section Invoking @command{guix environment}
4627 @cindex reproducible build environments
4628 @cindex development environments
4629 @cindex @command{guix environment}
4630 @cindex environment, package build environment
4631 The purpose of @command{guix environment} is to assist hackers in
4632 creating reproducible development environments without polluting their
4633 package profile. The @command{guix environment} tool takes one or more
4634 packages, builds all of their inputs, and creates a shell
4635 environment to use them.
4637 The general syntax is:
4640 guix environment @var{options} @var{package}@dots{}
4643 The following example spawns a new shell set up for the development of
4647 guix environment guile
4650 If the needed dependencies are not built yet, @command{guix environment}
4651 automatically builds them. The environment of the new shell is an augmented
4652 version of the environment that @command{guix environment} was run in.
4653 It contains the necessary search paths for building the given package
4654 added to the existing environment variables. To create a ``pure''
4655 environment, in which the original environment variables have been unset,
4656 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4657 environment variables such as @code{PATH} in their @file{~/.bashrc}
4658 file. As a consequence, when @code{guix environment} launches it, Bash
4659 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4660 environment variables. It is an error to define such environment
4661 variables in @file{.bashrc}; instead, they should be defined in
4662 @file{.bash_profile}, which is sourced only by log-in shells.
4663 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4664 details on Bash start-up files.}.
4666 @vindex GUIX_ENVIRONMENT
4667 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4668 variable in the shell it spawns; its value is the file name of the
4669 profile of this environment. This allows users to, say, define a
4670 specific prompt for development environments in their @file{.bashrc}
4671 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4674 if [ -n "$GUIX_ENVIRONMENT" ]
4676 export PS1="\u@@\h \w [dev]\$ "
4681 ...@: or to browse the profile:
4684 $ ls "$GUIX_ENVIRONMENT/bin"
4687 Additionally, more than one package may be specified, in which case the
4688 union of the inputs for the given packages are used. For example, the
4689 command below spawns a shell where all of the dependencies of both Guile
4690 and Emacs are available:
4693 guix environment guile emacs
4696 Sometimes an interactive shell session is not desired. An arbitrary
4697 command may be invoked by placing the @code{--} token to separate the
4698 command from the rest of the arguments:
4701 guix environment guile -- make -j4
4704 In other situations, it is more convenient to specify the list of
4705 packages needed in the environment. For example, the following command
4706 runs @command{python} from an environment containing Python@tie{}2.7 and
4710 guix environment --ad-hoc python2-numpy python-2.7 -- python
4713 Furthermore, one might want the dependencies of a package and also some
4714 additional packages that are not build-time or runtime dependencies, but
4715 are useful when developing nonetheless. Because of this, the
4716 @code{--ad-hoc} flag is positional. Packages appearing before
4717 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4718 added to the environment. Packages appearing after are interpreted as
4719 packages that will be added to the environment directly. For example,
4720 the following command creates a Guix development environment that
4721 additionally includes Git and strace:
4724 guix environment guix --ad-hoc git strace
4727 Sometimes it is desirable to isolate the environment as much as
4728 possible, for maximal purity and reproducibility. In particular, when
4729 using Guix on a host distro that is not Guix System, it is desirable to
4730 prevent access to @file{/usr/bin} and other system-wide resources from
4731 the development environment. For example, the following command spawns
4732 a Guile REPL in a ``container'' where only the store and the current
4733 working directory are mounted:
4736 guix environment --ad-hoc --container guile -- guile
4740 The @code{--container} option requires Linux-libre 3.19 or newer.
4743 The available options are summarized below.
4746 @item --root=@var{file}
4747 @itemx -r @var{file}
4748 @cindex persistent environment
4749 @cindex garbage collector root, for environments
4750 Make @var{file} a symlink to the profile for this environment, and
4751 register it as a garbage collector root.
4753 This is useful if you want to protect your environment from garbage
4754 collection, to make it ``persistent''.
4756 When this option is omitted, the environment is protected from garbage
4757 collection only for the duration of the @command{guix environment}
4758 session. This means that next time you recreate the same environment,
4759 you could have to rebuild or re-download packages. @xref{Invoking guix
4760 gc}, for more on GC roots.
4762 @item --expression=@var{expr}
4763 @itemx -e @var{expr}
4764 Create an environment for the package or list of packages that
4765 @var{expr} evaluates to.
4767 For example, running:
4770 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4773 starts a shell with the environment for this specific variant of the
4779 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4782 starts a shell with all the base system packages available.
4784 The above commands only use the default output of the given packages.
4785 To select other outputs, two element tuples can be specified:
4788 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4791 @item --load=@var{file}
4792 @itemx -l @var{file}
4793 Create an environment for the package or list of packages that the code
4794 within @var{file} evaluates to.
4796 As an example, @var{file} might contain a definition like this
4797 (@pxref{Defining Packages}):
4800 @verbatiminclude environment-gdb.scm
4803 @item --manifest=@var{file}
4804 @itemx -m @var{file}
4805 Create an environment for the packages contained in the manifest object
4806 returned by the Scheme code in @var{file}. This option can be repeated
4807 several times, in which case the manifests are concatenated.
4809 This is similar to the same-named option in @command{guix package}
4810 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4814 Include all specified packages in the resulting environment, as if an
4815 @i{ad hoc} package were defined with them as inputs. This option is
4816 useful for quickly creating an environment without having to write a
4817 package expression to contain the desired inputs.
4819 For instance, the command:
4822 guix environment --ad-hoc guile guile-sdl -- guile
4825 runs @command{guile} in an environment where Guile and Guile-SDL are
4828 Note that this example implicitly asks for the default output of
4829 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4830 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4831 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4833 This option may be composed with the default behavior of @command{guix
4834 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4835 as packages whose dependencies will be added to the environment, the
4836 default behavior. Packages appearing after are interpreted as packages
4837 that will be added to the environment directly.
4840 Unset existing environment variables when building the new environment, except
4841 those specified with @option{--preserve} (see below.) This has the effect of
4842 creating an environment in which search paths only contain package inputs.
4844 @item --preserve=@var{regexp}
4845 @itemx -E @var{regexp}
4846 When used alongside @option{--pure}, preserve the environment variables
4847 matching @var{regexp}---in other words, put them on a ``white list'' of
4848 environment variables that must be preserved. This option can be repeated
4852 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4856 This example runs @command{mpirun} in a context where the only environment
4857 variables defined are @code{PATH}, environment variables whose name starts
4858 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4861 @item --search-paths
4862 Display the environment variable definitions that make up the
4865 @item --system=@var{system}
4866 @itemx -s @var{system}
4867 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4872 Run @var{command} within an isolated container. The current working
4873 directory outside the container is mapped inside the container.
4874 Additionally, unless overridden with @code{--user}, a dummy home
4875 directory is created that matches the current user's home directory, and
4876 @file{/etc/passwd} is configured accordingly.
4878 The spawned process runs as the current user outside the container. Inside
4879 the container, it has the same UID and GID as the current user, unless
4880 @option{--user} is passed (see below.)
4884 For containers, share the network namespace with the host system.
4885 Containers created without this flag only have access to the loopback
4888 @item --link-profile
4890 For containers, link the environment profile to
4891 @file{~/.guix-profile} within the container. This is equivalent to
4892 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4893 within the container. Linking will fail and abort the environment if
4894 the directory already exists, which will certainly be the case if
4895 @command{guix environment} was invoked in the user's home directory.
4897 Certain packages are configured to look in
4898 @code{~/.guix-profile} for configuration files and data;@footnote{For
4899 example, the @code{fontconfig} package inspects
4900 @file{~/.guix-profile/share/fonts} for additional fonts.}
4901 @code{--link-profile} allows these programs to behave as expected within
4904 @item --user=@var{user}
4905 @itemx -u @var{user}
4906 For containers, use the username @var{user} in place of the current
4907 user. The generated @file{/etc/passwd} entry within the container will
4908 contain the name @var{user}, the home directory will be
4909 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4910 the UID and GID inside the container are 1000. @var{user}
4911 need not exist on the system.
4913 Additionally, any shared or exposed path (see @code{--share} and
4914 @code{--expose} respectively) whose target is within the current user's
4915 home directory will be remapped relative to @file{/home/USER}; this
4916 includes the automatic mapping of the current working directory.
4919 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4921 guix environment --container --user=foo \
4922 --expose=$HOME/test \
4923 --expose=/tmp/target=$HOME/target
4926 While this will limit the leaking of user identity through home paths
4927 and each of the user fields, this is only one useful component of a
4928 broader privacy/anonymity solution---not one in and of itself.
4931 For containers, the default behavior is to share the current working
4932 directory with the isolated container and immediately change to that
4933 directory within the container. If this is undesirable, @code{--no-cwd}
4934 will cause the current working directory to @emph{not} be automatically
4935 shared and will change to the user's home directory within the container
4936 instead. See also @code{--user}.
4938 @item --expose=@var{source}[=@var{target}]
4939 For containers, expose the file system @var{source} from the host system
4940 as the read-only file system @var{target} within the container. If
4941 @var{target} is not specified, @var{source} is used as the target mount
4942 point in the container.
4944 The example below spawns a Guile REPL in a container in which the user's
4945 home directory is accessible read-only via the @file{/exchange}
4949 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4952 @item --share=@var{source}[=@var{target}]
4953 For containers, share the file system @var{source} from the host system
4954 as the writable file system @var{target} within the container. If
4955 @var{target} is not specified, @var{source} is used as the target mount
4956 point in the container.
4958 The example below spawns a Guile REPL in a container in which the user's
4959 home directory is accessible for both reading and writing via the
4960 @file{/exchange} directory:
4963 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4967 @command{guix environment}
4968 also supports all of the common build options that @command{guix
4969 build} supports (@pxref{Common Build Options}) as well as package
4970 transformation options (@pxref{Package Transformation Options}).
4972 @node Invoking guix pack
4973 @section Invoking @command{guix pack}
4975 Occasionally you want to pass software to people who are not (yet!)
4976 lucky enough to be using Guix. You'd tell them to run @command{guix
4977 package -i @var{something}}, but that's not possible in this case. This
4978 is where @command{guix pack} comes in.
4981 If you are looking for ways to exchange binaries among machines that
4982 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4983 publish}, and @ref{Invoking guix archive}.
4988 @cindex application bundle
4989 @cindex software bundle
4990 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4991 @dfn{software bundle}: it creates a tarball or some other archive
4992 containing the binaries of the software you're interested in, and all
4993 its dependencies. The resulting archive can be used on any machine that
4994 does not have Guix, and people can run the exact same binaries as those
4995 you have with Guix. The pack itself is created in a bit-reproducible
4996 fashion, so anyone can verify that it really contains the build results
4997 that you pretend to be shipping.
4999 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5000 their dependencies, you can run:
5003 $ guix pack guile emacs geiser
5005 /gnu/store/@dots{}-pack.tar.gz
5008 The result here is a tarball containing a @file{/gnu/store} directory
5009 with all the relevant packages. The resulting tarball contains a
5010 @dfn{profile} with the three packages of interest; the profile is the
5011 same as would be created by @command{guix package -i}. It is this
5012 mechanism that is used to create Guix's own standalone binary tarball
5013 (@pxref{Binary Installation}).
5015 Users of this pack would have to run
5016 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5017 find inconvenient. To work around it, you can create, say, a
5018 @file{/opt/gnu/bin} symlink to the profile:
5021 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5025 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5027 @cindex relocatable binaries, with @command{guix pack}
5028 What if the recipient of your pack does not have root privileges on
5029 their machine, and thus cannot unpack it in the root file system? In
5030 that case, you will want to use the @code{--relocatable} option (see
5031 below). This option produces @dfn{relocatable binaries}, meaning they
5032 they can be placed anywhere in the file system hierarchy: in the example
5033 above, users can unpack your tarball in their home directory and
5034 directly run @file{./opt/gnu/bin/guile}.
5036 @cindex Docker, build an image with guix pack
5037 Alternatively, you can produce a pack in the Docker image format using
5038 the following command:
5041 guix pack -f docker guile emacs geiser
5045 The result is a tarball that can be passed to the @command{docker load}
5047 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5048 documentation} for more information.
5050 @cindex Singularity, build an image with guix pack
5051 @cindex SquashFS, build an image with guix pack
5052 Yet another option is to produce a SquashFS image with the following
5056 guix pack -f squashfs guile emacs geiser
5060 The result is a SquashFS file system image that can either be mounted or
5061 directly be used as a file system container image with the
5062 @uref{https://singularity.lbl.gov, Singularity container execution
5063 environment}, using commands like @command{singularity shell} or
5064 @command{singularity exec}.
5066 Several command-line options allow you to customize your pack:
5069 @item --format=@var{format}
5070 @itemx -f @var{format}
5071 Produce a pack in the given @var{format}.
5073 The available formats are:
5077 This is the default format. It produces a tarball containing all the
5078 specified binaries and symlinks.
5081 This produces a tarball that follows the
5082 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5083 Docker Image Specification}. The ``repository name'' as it appears in
5084 the output of the @command{docker images} command is computed from
5085 package names passed on the command line or in the manifest file.
5088 This produces a SquashFS image containing all the specified binaries and
5089 symlinks, as well as empty mount points for virtual file systems like
5093 @cindex relocatable binaries
5096 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5097 anywhere in the file system hierarchy and run from there.
5099 When this option is passed once, the resulting binaries require support for
5100 @dfn{user namespaces} in the kernel Linux; when passed
5101 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5102 PRoot support, can be thought of as the abbreviation of ``Really
5103 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5104 if user namespaces are unavailable, and essentially work anywhere---see below
5105 for the implications.
5107 For example, if you create a pack containing Bash with:
5110 guix pack -RR -S /mybin=bin bash
5114 ...@: you can copy that pack to a machine that lacks Guix, and from your
5115 home directory as a normal user, run:
5123 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5124 @file{/gnu/store} shows up and contains all the dependencies of
5125 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5126 altogether! That is probably the simplest way to deploy Guix-built
5127 software on a non-Guix machine.
5130 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5131 the kernel Linux, which allows unprivileged users to mount or change root.
5132 Old versions of Linux did not support it, and some GNU/Linux distributions
5135 To produce relocatable binaries that work even in the absence of user
5136 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5137 case, binaries will try user namespace support and fall back to PRoot if user
5138 namespaces are not supported.
5140 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5141 support for file system virtualization. It achieves that by using the
5142 @code{ptrace} system call on the running program. This approach has the
5143 advantage to work without requiring special kernel support, but it incurs
5144 run-time overhead every time a system call is made.
5147 @cindex entry point, for Docker images
5148 @item --entry-point=@var{command}
5149 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5150 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5151 support it. @var{command} must be relative to the profile contained in the
5154 The entry point specifies the command that tools like @code{docker run} or
5155 @code{singularity run} automatically start by default. For example, you can
5159 guix pack -f docker --entry-point=bin/guile guile
5162 The resulting pack can easily be loaded and @code{docker run} with no extra
5163 arguments will spawn @code{bin/guile}:
5166 docker load -i pack.tar.gz
5167 docker run @var{image-id}
5170 @item --expression=@var{expr}
5171 @itemx -e @var{expr}
5172 Consider the package @var{expr} evaluates to.
5174 This has the same purpose as the same-named option in @command{guix
5175 build} (@pxref{Additional Build Options, @code{--expression} in
5176 @command{guix build}}).
5178 @item --manifest=@var{file}
5179 @itemx -m @var{file}
5180 Use the packages contained in the manifest object returned by the Scheme
5181 code in @var{file}. This option can be repeated several times, in which
5182 case the manifests are concatenated.
5184 This has a similar purpose as the same-named option in @command{guix
5185 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5186 same manifest files. It allows you to define a collection of packages
5187 once and use it both for creating profiles and for creating archives
5188 for use on machines that do not have Guix installed. Note that you can
5189 specify @emph{either} a manifest file @emph{or} a list of packages,
5192 @item --system=@var{system}
5193 @itemx -s @var{system}
5194 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5195 the system type of the build host.
5197 @item --target=@var{triplet}
5198 @cindex cross-compilation
5199 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5200 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5201 configuration triplets,, autoconf, Autoconf}).
5203 @item --compression=@var{tool}
5204 @itemx -C @var{tool}
5205 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5206 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5208 @item --symlink=@var{spec}
5209 @itemx -S @var{spec}
5210 Add the symlinks specified by @var{spec} to the pack. This option can
5211 appear several times.
5213 @var{spec} has the form @code{@var{source}=@var{target}}, where
5214 @var{source} is the symlink that will be created and @var{target} is the
5217 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5218 symlink pointing to the @file{bin} sub-directory of the profile.
5220 @item --save-provenance
5221 Save provenance information for the packages passed on the command line.
5222 Provenance information includes the URL and commit of the channels in use
5225 Provenance information is saved in the
5226 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5227 usual package metadata---the name and version of each package, their
5228 propagated inputs, and so on. It is useful information to the recipient of
5229 the pack, who then knows how the pack was (supposedly) obtained.
5231 This option is not enabled by default because, like timestamps, provenance
5232 information contributes nothing to the build process. In other words, there
5233 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5234 Recording such ``silent'' metadata in the output thus potentially breaks the
5235 source-to-binary bitwise reproducibility property.
5237 @item --root=@var{file}
5238 @itemx -r @var{file}
5239 @cindex garbage collector root, for packs
5240 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5243 @item --localstatedir
5244 @itemx --profile-name=@var{name}
5245 Include the ``local state directory'', @file{/var/guix}, in the resulting
5246 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5247 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5248 @file{~root/.guix-profile}.
5250 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5251 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5252 the pack means that the store is ``complete'' and manageable by Guix;
5253 not providing it pack means that the store is ``dead'': items cannot be
5254 added to it or removed from it after extraction of the pack.
5256 One use case for this is the Guix self-contained binary tarball
5257 (@pxref{Binary Installation}).
5261 Print the name of the derivation that builds the pack.
5264 Use the bootstrap binaries to build the pack. This option is only
5265 useful to Guix developers.
5268 In addition, @command{guix pack} supports all the common build options
5269 (@pxref{Common Build Options}) and all the package transformation
5270 options (@pxref{Package Transformation Options}).
5273 @c *********************************************************************
5274 @node Programming Interface
5275 @chapter Programming Interface
5277 GNU Guix provides several Scheme programming interfaces (APIs) to
5278 define, build, and query packages. The first interface allows users to
5279 write high-level package definitions. These definitions refer to
5280 familiar packaging concepts, such as the name and version of a package,
5281 its build system, and its dependencies. These definitions can then be
5282 turned into concrete build actions.
5284 Build actions are performed by the Guix daemon, on behalf of users. In a
5285 standard setup, the daemon has write access to the store---the
5286 @file{/gnu/store} directory---whereas users do not. The recommended
5287 setup also has the daemon perform builds in chroots, under a specific
5288 build users, to minimize interference with the rest of the system.
5291 Lower-level APIs are available to interact with the daemon and the
5292 store. To instruct the daemon to perform a build action, users actually
5293 provide it with a @dfn{derivation}. A derivation is a low-level
5294 representation of the build actions to be taken, and the environment in
5295 which they should occur---derivations are to package definitions what
5296 assembly is to C programs. The term ``derivation'' comes from the fact
5297 that build results @emph{derive} from them.
5299 This chapter describes all these APIs in turn, starting from high-level
5300 package definitions.
5303 * Package Modules:: Packages from the programmer's viewpoint.
5304 * Defining Packages:: Defining new packages.
5305 * Build Systems:: Specifying how packages are built.
5306 * The Store:: Manipulating the package store.
5307 * Derivations:: Low-level interface to package derivations.
5308 * The Store Monad:: Purely functional interface to the store.
5309 * G-Expressions:: Manipulating build expressions.
5310 * Invoking guix repl:: Fiddling with Guix interactively.
5313 @node Package Modules
5314 @section Package Modules
5316 From a programming viewpoint, the package definitions of the
5317 GNU distribution are provided by Guile modules in the @code{(gnu packages
5318 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5319 packages @dots{})} module name space are not necessarily ``GNU
5320 packages''. This module naming scheme follows the usual Guile module
5321 naming convention: @code{gnu} means that these modules are distributed
5322 as part of the GNU system, and @code{packages} identifies modules that
5323 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5324 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5325 module exports a variable named @code{emacs}, which is bound to a
5326 @code{<package>} object (@pxref{Defining Packages}).
5328 The @code{(gnu packages @dots{})} module name space is
5329 automatically scanned for packages by the command-line tools. For
5330 instance, when running @code{guix install emacs}, all the @code{(gnu
5331 packages @dots{})} modules are scanned until one that exports a package
5332 object whose name is @code{emacs} is found. This package search
5333 facility is implemented in the @code{(gnu packages)} module.
5335 @cindex customization, of packages
5336 @cindex package module search path
5337 Users can store package definitions in modules with different
5338 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5339 name and module name must match. For instance, the @code{(my-packages
5340 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5341 relative to the load path specified with @option{--load-path} or
5342 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5343 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5344 these package definitions visible to the user interfaces:
5348 By adding the directory containing your package modules to the search path
5349 with the @code{-L} flag of @command{guix package} and other commands
5350 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5351 environment variable described below.
5354 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5355 pulls from it. A channel is essentially a Git repository containing package
5356 modules. @xref{Channels}, for more information on how to define and use
5360 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5362 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5363 This is a colon-separated list of directories to search for additional
5364 package modules. Directories listed in this variable take precedence
5365 over the own modules of the distribution.
5368 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5369 each package is built based solely on other packages in the
5370 distribution. The root of this dependency graph is a small set of
5371 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5372 bootstrap)} module. For more information on bootstrapping,
5373 @pxref{Bootstrapping}.
5375 @node Defining Packages
5376 @section Defining Packages
5378 The high-level interface to package definitions is implemented in the
5379 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5380 example, the package definition, or @dfn{recipe}, for the GNU Hello
5381 package looks like this:
5384 (define-module (gnu packages hello)
5385 #:use-module (guix packages)
5386 #:use-module (guix download)
5387 #:use-module (guix build-system gnu)
5388 #:use-module (guix licenses)
5389 #:use-module (gnu packages gawk))
5391 (define-public hello
5397 (uri (string-append "mirror://gnu/hello/hello-" version
5401 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5402 (build-system gnu-build-system)
5403 (arguments '(#:configure-flags '("--enable-silent-rules")))
5404 (inputs `(("gawk" ,gawk)))
5405 (synopsis "Hello, GNU world: An example GNU package")
5406 (description "Guess what GNU Hello prints!")
5407 (home-page "https://www.gnu.org/software/hello/")
5412 Without being a Scheme expert, the reader may have guessed the meaning
5413 of the various fields here. This expression binds the variable
5414 @code{hello} to a @code{<package>} object, which is essentially a record
5415 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5416 This package object can be inspected using procedures found in the
5417 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5418 returns---surprise!---@code{"hello"}.
5420 With luck, you may be able to import part or all of the definition of
5421 the package you are interested in from another repository, using the
5422 @code{guix import} command (@pxref{Invoking guix import}).
5424 In the example above, @var{hello} is defined in a module of its own,
5425 @code{(gnu packages hello)}. Technically, this is not strictly
5426 necessary, but it is convenient to do so: all the packages defined in
5427 modules under @code{(gnu packages @dots{})} are automatically known to
5428 the command-line tools (@pxref{Package Modules}).
5430 There are a few points worth noting in the above package definition:
5434 The @code{source} field of the package is an @code{<origin>} object
5435 (@pxref{origin Reference}, for the complete reference).
5436 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5437 meaning that the source is a file to be downloaded over FTP or HTTP.
5439 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5440 the GNU mirrors defined in @code{(guix download)}.
5442 The @code{sha256} field specifies the expected SHA256 hash of the file
5443 being downloaded. It is mandatory, and allows Guix to check the
5444 integrity of the file. The @code{(base32 @dots{})} form introduces the
5445 base32 representation of the hash. You can obtain this information with
5446 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5447 hash} (@pxref{Invoking guix hash}).
5450 When needed, the @code{origin} form can also have a @code{patches} field
5451 listing patches to be applied, and a @code{snippet} field giving a
5452 Scheme expression to modify the source code.
5455 @cindex GNU Build System
5456 The @code{build-system} field specifies the procedure to build the
5457 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5458 represents the familiar GNU Build System, where packages may be
5459 configured, built, and installed with the usual @code{./configure &&
5460 make && make check && make install} command sequence.
5463 The @code{arguments} field specifies options for the build system
5464 (@pxref{Build Systems}). Here it is interpreted by
5465 @var{gnu-build-system} as a request run @file{configure} with the
5466 @code{--enable-silent-rules} flag.
5472 What about these quote (@code{'}) characters? They are Scheme syntax to
5473 introduce a literal list; @code{'} is synonymous with @code{quote}.
5474 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5475 for details. Here the value of the @code{arguments} field is a list of
5476 arguments passed to the build system down the road, as with @code{apply}
5477 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5480 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5481 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5482 @code{#:configure-flags} is a keyword used to pass a keyword argument
5483 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5487 The @code{inputs} field specifies inputs to the build process---i.e.,
5488 build-time or run-time dependencies of the package. Here, we define an
5489 input called @code{"gawk"} whose value is that of the @var{gawk}
5490 variable; @var{gawk} is itself bound to a @code{<package>} object.
5492 @cindex backquote (quasiquote)
5495 @cindex comma (unquote)
5499 @findex unquote-splicing
5500 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5501 us to introduce a literal list in the @code{inputs} field, while
5502 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5503 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5506 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5507 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5508 of ensuring that they are present (@pxref{Build Systems}).
5510 However, any other dependencies need to be specified in the
5511 @code{inputs} field. Any dependency not specified here will simply be
5512 unavailable to the build process, possibly leading to a build failure.
5515 @xref{package Reference}, for a full description of possible fields.
5517 Once a package definition is in place, the
5518 package may actually be built using the @code{guix build} command-line
5519 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5520 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5521 package definition using the @command{guix edit} command
5522 (@pxref{Invoking guix edit}).
5523 @xref{Packaging Guidelines}, for
5524 more information on how to test package definitions, and
5525 @ref{Invoking guix lint}, for information on how to check a definition
5526 for style conformance.
5527 @vindex GUIX_PACKAGE_PATH
5528 Lastly, @pxref{Channels}, for information
5529 on how to extend the distribution by adding your own package definitions
5532 Finally, updating the package definition to a new upstream version
5533 can be partly automated by the @command{guix refresh} command
5534 (@pxref{Invoking guix refresh}).
5536 Behind the scenes, a derivation corresponding to the @code{<package>}
5537 object is first computed by the @code{package-derivation} procedure.
5538 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5539 The build actions it prescribes may then be realized by using the
5540 @code{build-derivations} procedure (@pxref{The Store}).
5542 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5543 Return the @code{<derivation>} object of @var{package} for @var{system}
5544 (@pxref{Derivations}).
5546 @var{package} must be a valid @code{<package>} object, and @var{system}
5547 must be a string denoting the target system type---e.g.,
5548 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5549 must be a connection to the daemon, which operates on the store
5550 (@pxref{The Store}).
5554 @cindex cross-compilation
5555 Similarly, it is possible to compute a derivation that cross-builds a
5556 package for some other system:
5558 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5559 @var{package} @var{target} [@var{system}]
5560 Return the @code{<derivation>} object of @var{package} cross-built from
5561 @var{system} to @var{target}.
5563 @var{target} must be a valid GNU triplet denoting the target hardware
5564 and operating system, such as @code{"mips64el-linux-gnu"}
5565 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5568 @cindex package transformations
5569 @cindex input rewriting
5570 @cindex dependency tree rewriting
5571 Packages can be manipulated in arbitrary ways. An example of a useful
5572 transformation is @dfn{input rewriting}, whereby the dependency tree of
5573 a package is rewritten by replacing specific inputs by others:
5575 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5576 [@var{rewrite-name}]
5577 Return a procedure that, when passed a package, replaces its direct and
5578 indirect dependencies (but not its implicit inputs) according to
5579 @var{replacements}. @var{replacements} is a list of package pairs; the
5580 first element of each pair is the package to replace, and the second one
5583 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5584 the name of a package and returns its new name after rewrite.
5588 Consider this example:
5591 (define libressl-instead-of-openssl
5592 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5594 (package-input-rewriting `((,openssl . ,libressl))))
5596 (define git-with-libressl
5597 (libressl-instead-of-openssl git))
5601 Here we first define a rewriting procedure that replaces @var{openssl}
5602 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5603 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5604 This is exactly what the @option{--with-input} command-line option does
5605 (@pxref{Package Transformation Options, @option{--with-input}}).
5607 The following variant of @code{package-input-rewriting} can match packages to
5608 be replaced by name rather than by identity.
5610 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5611 Return a procedure that, given a package, applies the given @var{replacements} to
5612 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5613 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5614 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5615 replacement for that package.
5618 The example above could be rewritten this way:
5621 (define libressl-instead-of-openssl
5622 ;; Replace all the packages called "openssl" with LibreSSL.
5623 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5626 The key difference here is that, this time, packages are matched by spec and
5627 not by identity. In other words, any package in the graph that is called
5628 @code{openssl} will be replaced.
5630 A more generic procedure to rewrite a package dependency graph is
5631 @code{package-mapping}: it supports arbitrary changes to nodes in the
5634 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5635 Return a procedure that, given a package, applies @var{proc} to all the packages
5636 depended on and returns the resulting package. The procedure stops recursion
5637 when @var{cut?} returns true for a given package.
5641 * package Reference:: The package data type.
5642 * origin Reference:: The origin data type.
5646 @node package Reference
5647 @subsection @code{package} Reference
5649 This section summarizes all the options available in @code{package}
5650 declarations (@pxref{Defining Packages}).
5652 @deftp {Data Type} package
5653 This is the data type representing a package recipe.
5657 The name of the package, as a string.
5659 @item @code{version}
5660 The version of the package, as a string.
5663 An object telling how the source code for the package should be
5664 acquired. Most of the time, this is an @code{origin} object, which
5665 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5666 can also be any other ``file-like'' object such as a @code{local-file},
5667 which denotes a file from the local file system (@pxref{G-Expressions,
5668 @code{local-file}}).
5670 @item @code{build-system}
5671 The build system that should be used to build the package (@pxref{Build
5674 @item @code{arguments} (default: @code{'()})
5675 The arguments that should be passed to the build system. This is a
5676 list, typically containing sequential keyword-value pairs.
5678 @item @code{inputs} (default: @code{'()})
5679 @itemx @code{native-inputs} (default: @code{'()})
5680 @itemx @code{propagated-inputs} (default: @code{'()})
5681 @cindex inputs, of packages
5682 These fields list dependencies of the package. Each one is a list of
5683 tuples, where each tuple has a label for the input (a string) as its
5684 first element, a package, origin, or derivation as its second element,
5685 and optionally the name of the output thereof that should be used, which
5686 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5687 more on package outputs). For example, the list below specifies three
5691 `(("libffi" ,libffi)
5692 ("libunistring" ,libunistring)
5693 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5696 @cindex cross compilation, package dependencies
5697 The distinction between @code{native-inputs} and @code{inputs} is
5698 necessary when considering cross-compilation. When cross-compiling,
5699 dependencies listed in @code{inputs} are built for the @emph{target}
5700 architecture; conversely, dependencies listed in @code{native-inputs}
5701 are built for the architecture of the @emph{build} machine.
5703 @code{native-inputs} is typically used to list tools needed at
5704 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5705 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5706 this area (@pxref{Invoking guix lint}).
5708 @anchor{package-propagated-inputs}
5709 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5710 specified packages will be automatically installed alongside the package
5711 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5712 package}}, for information on how @command{guix package} deals with
5715 For example this is necessary when a C/C++ library needs headers of
5716 another library to compile, or when a pkg-config file refers to another
5717 one @i{via} its @code{Requires} field.
5719 Another example where @code{propagated-inputs} is useful is for languages
5720 that lack a facility to record the run-time search path akin to the
5721 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5722 more. To ensure that libraries written in those languages can find
5723 library code they depend on at run time, run-time dependencies must be
5724 listed in @code{propagated-inputs} rather than @code{inputs}.
5726 @item @code{outputs} (default: @code{'("out")})
5727 The list of output names of the package. @xref{Packages with Multiple
5728 Outputs}, for typical uses of additional outputs.
5730 @item @code{native-search-paths} (default: @code{'()})
5731 @itemx @code{search-paths} (default: @code{'()})
5732 A list of @code{search-path-specification} objects describing
5733 search-path environment variables honored by the package.
5735 @item @code{replacement} (default: @code{#f})
5736 This must be either @code{#f} or a package object that will be used as a
5737 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5740 @item @code{synopsis}
5741 A one-line description of the package.
5743 @item @code{description}
5744 A more elaborate description of the package.
5746 @item @code{license}
5747 @cindex license, of packages
5748 The license of the package; a value from @code{(guix licenses)},
5749 or a list of such values.
5751 @item @code{home-page}
5752 The URL to the home-page of the package, as a string.
5754 @item @code{supported-systems} (default: @var{%supported-systems})
5755 The list of systems supported by the package, as strings of the form
5756 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5758 @item @code{location} (default: source location of the @code{package} form)
5759 The source location of the package. It is useful to override this when
5760 inheriting from another package, in which case this field is not
5761 automatically corrected.
5765 @deffn {Scheme Syntax} this-package
5766 When used in the @emph{lexical scope} of a package field definition, this
5767 identifier resolves to the package being defined.
5769 The example below shows how to add a package as a native input of itself when
5777 ;; When cross-compiled, Guile, for example, depends on
5778 ;; a native version of itself. Add it here.
5779 (native-inputs (if (%current-target-system)
5780 `(("self" ,this-package))
5784 It is an error to refer to @code{this-package} outside a package definition.
5787 @node origin Reference
5788 @subsection @code{origin} Reference
5790 This section summarizes all the options available in @code{origin}
5791 declarations (@pxref{Defining Packages}).
5793 @deftp {Data Type} origin
5794 This is the data type representing a source code origin.
5798 An object containing the URI of the source. The object type depends on
5799 the @code{method} (see below). For example, when using the
5800 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5801 values are: a URL represented as a string, or a list thereof.
5804 A procedure that handles the URI.
5809 @item @var{url-fetch} from @code{(guix download)}
5810 download a file from the HTTP, HTTPS, or FTP URL specified in the
5814 @item @var{git-fetch} from @code{(guix git-download)}
5815 clone the Git version control repository, and check out the revision
5816 specified in the @code{uri} field as a @code{git-reference} object; a
5817 @code{git-reference} looks like this:
5821 (url "https://git.savannah.gnu.org/git/hello.git")
5827 A bytevector containing the SHA-256 hash of the source. Typically the
5828 @code{base32} form is used here to generate the bytevector from a
5831 You can obtain this information using @code{guix download}
5832 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5835 @item @code{file-name} (default: @code{#f})
5836 The file name under which the source code should be saved. When this is
5837 @code{#f}, a sensible default value will be used in most cases. In case
5838 the source is fetched from a URL, the file name from the URL will be
5839 used. For version control checkouts, it is recommended to provide the
5840 file name explicitly because the default is not very descriptive.
5842 @item @code{patches} (default: @code{'()})
5843 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5844 file-like objects}) pointing to patches to be applied to the source.
5846 This list of patches must be unconditional. In particular, it cannot
5847 depend on the value of @code{%current-system} or
5848 @code{%current-target-system}.
5850 @item @code{snippet} (default: @code{#f})
5851 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5852 in the source directory. This is a convenient way to modify the source,
5853 sometimes more convenient than a patch.
5855 @item @code{patch-flags} (default: @code{'("-p1")})
5856 A list of command-line flags that should be passed to the @code{patch}
5859 @item @code{patch-inputs} (default: @code{#f})
5860 Input packages or derivations to the patching process. When this is
5861 @code{#f}, the usual set of inputs necessary for patching are provided,
5862 such as GNU@tie{}Patch.
5864 @item @code{modules} (default: @code{'()})
5865 A list of Guile modules that should be loaded during the patching
5866 process and while running the code in the @code{snippet} field.
5868 @item @code{patch-guile} (default: @code{#f})
5869 The Guile package that should be used in the patching process. When
5870 this is @code{#f}, a sensible default is used.
5876 @section Build Systems
5878 @cindex build system
5879 Each package definition specifies a @dfn{build system} and arguments for
5880 that build system (@pxref{Defining Packages}). This @code{build-system}
5881 field represents the build procedure of the package, as well as implicit
5882 dependencies of that build procedure.
5884 Build systems are @code{<build-system>} objects. The interface to
5885 create and manipulate them is provided by the @code{(guix build-system)}
5886 module, and actual build systems are exported by specific modules.
5888 @cindex bag (low-level package representation)
5889 Under the hood, build systems first compile package objects to
5890 @dfn{bags}. A @dfn{bag} is like a package, but with less
5891 ornamentation---in other words, a bag is a lower-level representation of
5892 a package, which includes all the inputs of that package, including some
5893 that were implicitly added by the build system. This intermediate
5894 representation is then compiled to a derivation (@pxref{Derivations}).
5896 Build systems accept an optional list of @dfn{arguments}. In package
5897 definitions, these are passed @i{via} the @code{arguments} field
5898 (@pxref{Defining Packages}). They are typically keyword arguments
5899 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5900 Guile Reference Manual}). The value of these arguments is usually
5901 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5902 by the daemon (@pxref{Derivations}).
5904 The main build system is @var{gnu-build-system}, which implements the
5905 standard build procedure for GNU and many other packages. It
5906 is provided by the @code{(guix build-system gnu)} module.
5908 @defvr {Scheme Variable} gnu-build-system
5909 @var{gnu-build-system} represents the GNU Build System, and variants
5910 thereof (@pxref{Configuration, configuration and makefile conventions,,
5911 standards, GNU Coding Standards}).
5913 @cindex build phases
5914 In a nutshell, packages using it are configured, built, and installed with
5915 the usual @code{./configure && make && make check && make install}
5916 command sequence. In practice, a few additional steps are often needed.
5917 All these steps are split up in separate @dfn{phases},
5918 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5919 modules for more details about the build phases.}:
5923 Unpack the source tarball, and change the current directory to the
5924 extracted source tree. If the source is actually a directory, copy it
5925 to the build tree, and enter that directory.
5927 @item patch-source-shebangs
5928 Patch shebangs encountered in source files so they refer to the right
5929 store file names. For instance, this changes @code{#!/bin/sh} to
5930 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5933 Run the @file{configure} script with a number of default options, such
5934 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5935 by the @code{#:configure-flags} argument.
5938 Run @code{make} with the list of flags specified with
5939 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5940 (the default), build with @code{make -j}.
5943 Run @code{make check}, or some other target specified with
5944 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5945 @code{#:parallel-tests?} argument is true (the default), run @code{make
5949 Run @code{make install} with the flags listed in @code{#:make-flags}.
5951 @item patch-shebangs
5952 Patch shebangs on the installed executable files.
5955 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5956 is false), copying them to the @code{debug} output when available
5957 (@pxref{Installing Debugging Files}).
5960 @vindex %standard-phases
5961 The build-side module @code{(guix build gnu-build-system)} defines
5962 @var{%standard-phases} as the default list of build phases.
5963 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5964 procedure implements the actual phase.
5966 The list of phases used for a particular package can be changed with the
5967 @code{#:phases} parameter. For instance, passing:
5970 #:phases (modify-phases %standard-phases (delete 'configure))
5973 means that all the phases described above will be used, except the
5974 @code{configure} phase.
5976 In addition, this build system ensures that the ``standard'' environment
5977 for GNU packages is available. This includes tools such as GCC, libc,
5978 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5979 build-system gnu)} module for a complete list). We call these the
5980 @dfn{implicit inputs} of a package, because package definitions do not
5981 have to mention them.
5984 Other @code{<build-system>} objects are defined to support other
5985 conventions and tools used by free software packages. They inherit most
5986 of @var{gnu-build-system}, and differ mainly in the set of inputs
5987 implicitly added to the build process, and in the list of phases
5988 executed. Some of these build systems are listed below.
5990 @defvr {Scheme Variable} ant-build-system
5991 This variable is exported by @code{(guix build-system ant)}. It
5992 implements the build procedure for Java packages that can be built with
5993 @url{https://ant.apache.org/, Ant build tool}.
5995 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5996 provided by the @code{icedtea} package to the set of inputs. Different
5997 packages can be specified with the @code{#:ant} and @code{#:jdk}
5998 parameters, respectively.
6000 When the original package does not provide a suitable Ant build file,
6001 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6002 build file @file{build.xml} with tasks to build the specified jar
6003 archive. In this case the parameter @code{#:source-dir} can be used to
6004 specify the source sub-directory, defaulting to ``src''.
6006 The @code{#:main-class} parameter can be used with the minimal ant
6007 buildfile to specify the main class of the resulting jar. This makes the
6008 jar file executable. The @code{#:test-include} parameter can be used to
6009 specify the list of junit tests to run. It defaults to
6010 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6011 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6012 because abstract classes cannot be run as tests.
6014 The parameter @code{#:build-target} can be used to specify the Ant task
6015 that should be run during the @code{build} phase. By default the
6016 ``jar'' task will be run.
6020 @defvr {Scheme Variable} android-ndk-build-system
6021 @cindex Android distribution
6022 @cindex Android NDK build system
6023 This variable is exported by @code{(guix build-system android-ndk)}. It
6024 implements a build procedure for Android NDK (native development kit)
6025 packages using a Guix-specific build process.
6027 The build system assumes that packages install their public interface
6028 (header) files to the subdirectory "include" of the "out" output and
6029 their libraries to the subdirectory "lib" of the "out" output.
6031 It's also assumed that the union of all the dependencies of a package
6032 has no conflicting files.
6034 For the time being, cross-compilation is not supported - so right now
6035 the libraries and header files are assumed to be host tools.
6039 @defvr {Scheme Variable} asdf-build-system/source
6040 @defvrx {Scheme Variable} asdf-build-system/sbcl
6041 @defvrx {Scheme Variable} asdf-build-system/ecl
6043 These variables, exported by @code{(guix build-system asdf)}, implement
6044 build procedures for Common Lisp packages using
6045 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6046 definition facility for Common Lisp programs and libraries.
6048 The @code{asdf-build-system/source} system installs the packages in
6049 source form, and can be loaded using any common lisp implementation, via
6050 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6051 systems in the format which a particular implementation understands.
6052 These build systems can also be used to produce executable programs, or
6053 lisp images which contain a set of packages pre-loaded.
6055 The build system uses naming conventions. For binary packages, the
6056 package name should be prefixed with the lisp implementation, such as
6057 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6059 Additionally, the corresponding source package should be labeled using
6060 the same convention as python packages (see @ref{Python Modules}), using
6061 the @code{cl-} prefix.
6063 For binary packages, each system should be defined as a Guix package.
6064 If one package @code{origin} contains several systems, package variants
6065 can be created in order to build all the systems. Source packages,
6066 which use @code{asdf-build-system/source}, may contain several systems.
6068 In order to create executable programs and images, the build-side
6069 procedures @code{build-program} and @code{build-image} can be used.
6070 They should be called in a build phase after the @code{create-symlinks}
6071 phase, so that the system which was just built can be used within the
6072 resulting image. @code{build-program} requires a list of Common Lisp
6073 expressions to be passed as the @code{#:entry-program} argument.
6075 If the system is not defined within its own @code{.asd} file of the same
6076 name, then the @code{#:asd-file} parameter should be used to specify
6077 which file the system is defined in. Furthermore, if the package
6078 defines a system for its tests in a separate file, it will be loaded
6079 before the tests are run if it is specified by the
6080 @code{#:test-asd-file} parameter. If it is not set, the files
6081 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6082 and @code{test.asd} will be tried if they exist.
6084 If for some reason the package must be named in a different way than the
6085 naming conventions suggest, the @code{#:asd-system-name} parameter can
6086 be used to specify the name of the system.
6090 @defvr {Scheme Variable} cargo-build-system
6091 @cindex Rust programming language
6092 @cindex Cargo (Rust build system)
6093 This variable is exported by @code{(guix build-system cargo)}. It
6094 supports builds of packages using Cargo, the build tool of the
6095 @uref{https://www.rust-lang.org, Rust programming language}.
6097 It adds @code{rustc} and @code{cargo} to the set of inputs.
6098 A different Rust package can be specified with the @code{#:rust} parameter.
6100 Regular cargo dependencies should be added to the package definition via the
6101 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6102 spec can be a package or a source definition. Note that the spec must
6103 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6104 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6105 should be added to the package definition via the
6106 @code{#:cargo-development-inputs} parameter.
6108 In its @code{configure} phase, this build system will make any source inputs
6109 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6110 parameters available to cargo. It will also remove an included
6111 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6112 @code{build} phase. The @code{install} phase installs any crate the binaries
6113 if they are defined by the crate.
6116 @cindex Clojure (programming language)
6117 @cindex simple Clojure build system
6118 @defvr {Scheme Variable} clojure-build-system
6119 This variable is exported by @code{(guix build-system clojure)}. It implements
6120 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6121 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6124 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6125 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6126 @code{#:zip} parameters, respectively.
6128 A list of source directories, test directories and jar names can be specified
6129 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6130 parameters, respectively. Compile directory and main class can be specified
6131 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6132 Other parameters are documented below.
6134 This build system is an extension of @var{ant-build-system}, but with the
6135 following phases changed:
6140 This phase calls @code{compile} in Clojure to compile source files and runs
6141 @command{jar} to create jars from both source files and compiled files
6142 according to the include list and exclude list specified in
6143 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6144 has priority over the include list. These lists consist of symbols
6145 representing Clojure libraries or the special keyword @code{#:all} representing
6146 all Clojure libraries found under the source directories. The parameter
6147 @code{#:omit-source?} decides if source should be included into the jars.
6150 This phase runs tests according to the include list and exclude list specified
6151 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6152 meanings are analogous to that of @code{#:aot-include} and
6153 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6154 stands for all Clojure libraries found under the test directories. The
6155 parameter @code{#:tests?} decides if tests should be run.
6158 This phase installs all jars built previously.
6161 Apart from the above, this build system also contains an additional phase:
6166 This phase installs all top-level files with base name matching
6167 @var{%doc-regex}. A different regex can be specified with the
6168 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6169 directories specified in @code{#:doc-dirs} are installed as well.
6173 @defvr {Scheme Variable} cmake-build-system
6174 This variable is exported by @code{(guix build-system cmake)}. It
6175 implements the build procedure for packages using the
6176 @url{https://www.cmake.org, CMake build tool}.
6178 It automatically adds the @code{cmake} package to the set of inputs.
6179 Which package is used can be specified with the @code{#:cmake}
6182 The @code{#:configure-flags} parameter is taken as a list of flags
6183 passed to the @command{cmake} command. The @code{#:build-type}
6184 parameter specifies in abstract terms the flags passed to the compiler;
6185 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6186 debugging information''), which roughly means that code is compiled with
6187 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6190 @defvr {Scheme Variable} dune-build-system
6191 This variable is exported by @code{(guix build-system dune)}. It
6192 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6193 tool for the OCaml programming language. It is implemented as an extension
6194 of the @code{ocaml-build-system} which is described below. As such, the
6195 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6198 It automatically adds the @code{dune} package to the set of inputs.
6199 Which package is used can be specified with the @code{#:dune}
6202 There is no @code{configure} phase because dune packages typically don't
6203 need to be configured. The @code{#:build-flags} parameter is taken as a
6204 list of flags passed to the @code{dune} command during the build.
6206 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6207 command instead of the more recent @code{dune} command while building
6208 a package. Its default value is @code{#f}.
6210 The @code{#:package} parameter can be passed to specify a package name, which
6211 is useful when a package contains multiple packages and you want to build
6212 only one of them. This is equivalent to passing the @code{-p} argument to
6216 @defvr {Scheme Variable} go-build-system
6217 This variable is exported by @code{(guix build-system go)}. It
6218 implements a build procedure for Go packages using the standard
6219 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6220 Go build mechanisms}.
6222 The user is expected to provide a value for the key @code{#:import-path}
6223 and, in some cases, @code{#:unpack-path}. The
6224 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6225 corresponds to the file system path expected by the package's build
6226 scripts and any referring packages, and provides a unique way to
6227 refer to a Go package. It is typically based on a combination of the
6228 package source code's remote URI and file system hierarchy structure. In
6229 some cases, you will need to unpack the package's source code to a
6230 different directory structure than the one indicated by the import path,
6231 and @code{#:unpack-path} should be used in such cases.
6233 Packages that provide Go libraries should install their source code into
6234 the built output. The key @code{#:install-source?}, which defaults to
6235 @code{#t}, controls whether or not the source code is installed. It can
6236 be set to @code{#f} for packages that only provide executable files.
6239 @defvr {Scheme Variable} glib-or-gtk-build-system
6240 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6241 is intended for use with packages making use of GLib or GTK+.
6243 This build system adds the following two phases to the ones defined by
6244 @var{gnu-build-system}:
6247 @item glib-or-gtk-wrap
6248 The phase @code{glib-or-gtk-wrap} ensures that programs in
6249 @file{bin/} are able to find GLib ``schemas'' and
6250 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6251 modules}. This is achieved by wrapping the programs in launch scripts
6252 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6253 environment variables.
6255 It is possible to exclude specific package outputs from that wrapping
6256 process by listing their names in the
6257 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6258 when an output is known not to contain any GLib or GTK+ binaries, and
6259 where wrapping would gratuitously add a dependency of that output on
6262 @item glib-or-gtk-compile-schemas
6263 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6264 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6265 GSettings schemas} of GLib are compiled. Compilation is performed by the
6266 @command{glib-compile-schemas} program. It is provided by the package
6267 @code{glib:bin} which is automatically imported by the build system.
6268 The @code{glib} package providing @command{glib-compile-schemas} can be
6269 specified with the @code{#:glib} parameter.
6272 Both phases are executed after the @code{install} phase.
6275 @defvr {Scheme Variable} guile-build-system
6276 This build system is for Guile packages that consist exclusively of Scheme
6277 code and that are so lean that they don't even have a makefile, let alone a
6278 @file{configure} script. It compiles Scheme code using @command{guild
6279 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6280 installs the @file{.scm} and @file{.go} files in the right place. It also
6281 installs documentation.
6283 This build system supports cross-compilation by using the @code{--target}
6284 option of @command{guild compile}.
6286 Packages built with @code{guile-build-system} must provide a Guile package in
6287 their @code{native-inputs} field.
6290 @defvr {Scheme Variable} julia-build-system
6291 This variable is exported by @code{(guix build-system julia)}. It implements
6292 the build procedure used by @uref{https://julialang.org/, julia} packages,
6293 which essentially is similar to running @command{julia -e 'using Pkg;
6294 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6295 paths to all Julia package inputs. Tests are run not run.
6297 Julia packages require the source @code{file-name} to be the real name of the
6298 package, correctly capitalized.
6300 For packages requiring shared library dependencies, you may need to write the
6301 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6302 variable = /gnu/store/library.so} for each dependency, plus a void function
6303 @code{check_deps() = nothing}.
6305 Some older packages that aren't using @file{Package.toml} yet, will require
6306 this file to be created, too. The function @code{julia-create-package-toml}
6307 helps creating the file. You need to pass the outputs and the source of the
6308 package, it's name (the same as the @code{file-name} parameter), the package
6309 uuid, the package version, and a list of dependencies specified by their name
6313 @defvr {Scheme Variable} minify-build-system
6314 This variable is exported by @code{(guix build-system minify)}. It
6315 implements a minification procedure for simple JavaScript packages.
6317 It adds @code{uglify-js} to the set of inputs and uses it to compress
6318 all JavaScript files in the @file{src} directory. A different minifier
6319 package can be specified with the @code{#:uglify-js} parameter, but it
6320 is expected that the package writes the minified code to the standard
6323 When the input JavaScript files are not all located in the @file{src}
6324 directory, the parameter @code{#:javascript-files} can be used to
6325 specify a list of file names to feed to the minifier.
6328 @defvr {Scheme Variable} ocaml-build-system
6329 This variable is exported by @code{(guix build-system ocaml)}. It implements
6330 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6331 of choosing the correct set of commands to run for each package. OCaml
6332 packages can expect many different commands to be run. This build system will
6335 When the package has a @file{setup.ml} file present at the top-level, it will
6336 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6337 @code{ocaml setup.ml -install}. The build system will assume that this file
6338 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6339 care of setting the prefix and enabling tests if they are not disabled. You
6340 can pass configure and build flags with the @code{#:configure-flags} and
6341 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6342 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6343 bypass this system in the build and install phases.
6345 When the package has a @file{configure} file, it is assumed that it is a
6346 hand-made configure script that requires a different argument format than
6347 in the @code{gnu-build-system}. You can add more flags with the
6348 @code{#:configure-flags} key.
6350 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6351 @code{#t}), it will be used and more flags can be passed to the build and
6352 install phases with the @code{#:make-flags} key.
6354 Finally, some packages do not have these files and use a somewhat standard
6355 location for its build system. In that case, the build system will run
6356 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6357 providing the path to the required findlib module. Additional flags can
6358 be passed via the @code{#:build-flags} key. Install is taken care of by
6359 @command{opam-installer}. In this case, the @code{opam} package must
6360 be added to the @code{native-inputs} field of the package definition.
6362 Note that most OCaml packages assume they will be installed in the same
6363 directory as OCaml, which is not what we want in guix. In particular, they
6364 will install @file{.so} files in their module's directory, which is usually
6365 fine because it is in the OCaml compiler directory. In guix though, these
6366 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6367 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6368 @file{.so} libraries should be installed.
6371 @defvr {Scheme Variable} python-build-system
6372 This variable is exported by @code{(guix build-system python)}. It
6373 implements the more or less standard build procedure used by Python
6374 packages, which consists in running @code{python setup.py build} and
6375 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6377 For packages that install stand-alone Python programs under @code{bin/},
6378 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6379 environment variable points to all the Python libraries they depend on.
6381 Which Python package is used to perform the build can be specified with
6382 the @code{#:python} parameter. This is a useful way to force a package
6383 to be built for a specific version of the Python interpreter, which
6384 might be necessary if the package is only compatible with a single
6385 interpreter version.
6387 By default guix calls @code{setup.py} under control of
6388 @code{setuptools}, much like @command{pip} does. Some packages are not
6389 compatible with setuptools (and pip), thus you can disable this by
6390 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6393 @defvr {Scheme Variable} perl-build-system
6394 This variable is exported by @code{(guix build-system perl)}. It
6395 implements the standard build procedure for Perl packages, which either
6396 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6397 followed by @code{Build} and @code{Build install}; or in running
6398 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6399 @code{make} and @code{make install}, depending on which of
6400 @code{Build.PL} or @code{Makefile.PL} is present in the package
6401 distribution. Preference is given to the former if both @code{Build.PL}
6402 and @code{Makefile.PL} exist in the package distribution. This
6403 preference can be reversed by specifying @code{#t} for the
6404 @code{#:make-maker?} parameter.
6406 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6407 passes flags specified by the @code{#:make-maker-flags} or
6408 @code{#:module-build-flags} parameter, respectively.
6410 Which Perl package is used can be specified with @code{#:perl}.
6413 @defvr {Scheme Variable} qt-build-system
6414 This variable is exported by @code{(guix build-system qt)}. It
6415 is intended for use with applications using Qt or KDE.
6417 This build system adds the phase @code{qt-wrap} to the ones defined by
6418 @var{cmake-build-system}, after the @code{install} phase.
6420 This phase searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6421 and output. In case some path is found, all programs in the output's
6422 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6423 are wrapped in scripts defining the necessary environment variables.
6425 It is possible to exclude specific package outputs from that wrapping process
6426 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6427 This is useful when an output is known not to contain any Qt binaries, and
6428 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6432 @defvr {Scheme Variable} r-build-system
6433 This variable is exported by @code{(guix build-system r)}. It
6434 implements the build procedure used by @uref{https://r-project.org, R}
6435 packages, which essentially is little more than running @code{R CMD
6436 INSTALL --library=/gnu/store/@dots{}} in an environment where
6437 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6438 are run after installation using the R function
6439 @code{tools::testInstalledPackage}.
6442 @defvr {Scheme Variable} rakudo-build-system
6443 This variable is exported by @code{(guix build-system rakudo)}. It
6444 implements the build procedure used by @uref{https://rakudo.org/,
6445 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6446 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6447 installs the binaries, library files and the resources, as well as wrap
6448 the files under the @code{bin/} directory. Tests can be skipped by
6449 passing @code{#f} to the @code{tests?} parameter.
6451 Which rakudo package is used can be specified with @code{rakudo}.
6452 Which perl6-tap-harness package used for the tests can be specified with
6453 @code{#:prove6} or removed by passing @code{#f} to the
6454 @code{with-prove6?} parameter.
6455 Which perl6-zef package used for tests and installing can be specified
6456 with @code{#:zef} or removed by passing @code{#f} to the
6457 @code{with-zef?} parameter.
6460 @defvr {Scheme Variable} texlive-build-system
6461 This variable is exported by @code{(guix build-system texlive)}. It is
6462 used to build TeX packages in batch mode with a specified engine. The
6463 build system sets the @code{TEXINPUTS} variable to find all TeX source
6464 files in the inputs.
6466 By default it runs @code{luatex} on all files ending on @code{ins}. A
6467 different engine and format can be specified with the
6468 @code{#:tex-format} argument. Different build targets can be specified
6469 with the @code{#:build-targets} argument, which expects a list of file
6470 names. The build system adds only @code{texlive-bin} and
6471 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6472 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6473 and @code{#:texlive-latex-base}, respectively.
6475 The @code{#:tex-directory} parameter tells the build system where to
6476 install the built files under the texmf tree.
6479 @defvr {Scheme Variable} ruby-build-system
6480 This variable is exported by @code{(guix build-system ruby)}. It
6481 implements the RubyGems build procedure used by Ruby packages, which
6482 involves running @code{gem build} followed by @code{gem install}.
6484 The @code{source} field of a package that uses this build system
6485 typically references a gem archive, since this is the format that Ruby
6486 developers use when releasing their software. The build system unpacks
6487 the gem archive, potentially patches the source, runs the test suite,
6488 repackages the gem, and installs it. Additionally, directories and
6489 tarballs may be referenced to allow building unreleased gems from Git or
6490 a traditional source release tarball.
6492 Which Ruby package is used can be specified with the @code{#:ruby}
6493 parameter. A list of additional flags to be passed to the @command{gem}
6494 command can be specified with the @code{#:gem-flags} parameter.
6497 @defvr {Scheme Variable} waf-build-system
6498 This variable is exported by @code{(guix build-system waf)}. It
6499 implements a build procedure around the @code{waf} script. The common
6500 phases---@code{configure}, @code{build}, and @code{install}---are
6501 implemented by passing their names as arguments to the @code{waf}
6504 The @code{waf} script is executed by the Python interpreter. Which
6505 Python package is used to run the script can be specified with the
6506 @code{#:python} parameter.
6509 @defvr {Scheme Variable} scons-build-system
6510 This variable is exported by @code{(guix build-system scons)}. It
6511 implements the build procedure used by the SCons software construction
6512 tool. This build system runs @code{scons} to build the package,
6513 @code{scons test} to run tests, and then @code{scons install} to install
6516 Additional flags to be passed to @code{scons} can be specified with the
6517 @code{#:scons-flags} parameter. The default build and install targets
6518 can be overridden with @code{#:build-targets} and
6519 @code{#:install-targets} respectively. The version of Python used to
6520 run SCons can be specified by selecting the appropriate SCons package
6521 with the @code{#:scons} parameter.
6524 @defvr {Scheme Variable} haskell-build-system
6525 This variable is exported by @code{(guix build-system haskell)}. It
6526 implements the Cabal build procedure used by Haskell packages, which
6527 involves running @code{runhaskell Setup.hs configure
6528 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6529 Instead of installing the package by running @code{runhaskell Setup.hs
6530 install}, to avoid trying to register libraries in the read-only
6531 compiler store directory, the build system uses @code{runhaskell
6532 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6533 addition, the build system generates the package documentation by
6534 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6535 is passed. Optional Haddock parameters can be passed with the help of
6536 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6537 not found, the build system looks for @code{Setup.lhs} instead.
6539 Which Haskell compiler is used can be specified with the @code{#:haskell}
6540 parameter which defaults to @code{ghc}.
6543 @defvr {Scheme Variable} dub-build-system
6544 This variable is exported by @code{(guix build-system dub)}. It
6545 implements the Dub build procedure used by D packages, which
6546 involves running @code{dub build} and @code{dub run}.
6547 Installation is done by copying the files manually.
6549 Which D compiler is used can be specified with the @code{#:ldc}
6550 parameter which defaults to @code{ldc}.
6553 @defvr {Scheme Variable} emacs-build-system
6554 This variable is exported by @code{(guix build-system emacs)}. It
6555 implements an installation procedure similar to the packaging system
6556 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6558 It first creates the @code{@var{package}-autoloads.el} file, then it
6559 byte compiles all Emacs Lisp files. Differently from the Emacs
6560 packaging system, the Info documentation files are moved to the standard
6561 documentation directory and the @file{dir} file is deleted. Each
6562 package is installed in its own directory under
6563 @file{share/emacs/site-lisp/guix.d}.
6566 @defvr {Scheme Variable} font-build-system
6567 This variable is exported by @code{(guix build-system font)}. It
6568 implements an installation procedure for font packages where upstream
6569 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6570 need to be copied into place. It copies font files to standard
6571 locations in the output directory.
6574 @defvr {Scheme Variable} meson-build-system
6575 This variable is exported by @code{(guix build-system meson)}. It
6576 implements the build procedure for packages that use
6577 @url{https://mesonbuild.com, Meson} as their build system.
6579 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6580 of inputs, and they can be changed with the parameters @code{#:meson}
6581 and @code{#:ninja} if needed. The default Meson is
6582 @code{meson-for-build}, which is special because it doesn't clear the
6583 @code{RUNPATH} of binaries and libraries when they are installed.
6585 This build system is an extension of @var{gnu-build-system}, but with the
6586 following phases changed to some specific for Meson:
6591 The phase runs @code{meson} with the flags specified in
6592 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6593 @code{plain} unless something else is specified in @code{#:build-type}.
6596 The phase runs @code{ninja} to build the package in parallel by default, but
6597 this can be changed with @code{#:parallel-build?}.
6600 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6601 which is @code{"test"} by default.
6604 The phase runs @code{ninja install} and can not be changed.
6607 Apart from that, the build system also adds the following phases:
6612 This phase ensures that all binaries can find the libraries they need.
6613 It searches for required libraries in subdirectories of the package being
6614 built, and adds those to @code{RUNPATH} where needed. It also removes
6615 references to libraries left over from the build phase by
6616 @code{meson-for-build}, such as test dependencies, that aren't actually
6617 required for the program to run.
6619 @item glib-or-gtk-wrap
6620 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6621 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6623 @item glib-or-gtk-compile-schemas
6624 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6625 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6629 @defvr {Scheme Variable} linux-module-build-system
6630 @var{linux-module-build-system} allows building Linux kernel modules.
6632 @cindex build phases
6633 This build system is an extension of @var{gnu-build-system}, but with the
6634 following phases changed:
6639 This phase configures the environment so that the Linux kernel's Makefile
6640 can be used to build the external kernel module.
6643 This phase uses the Linux kernel's Makefile in order to build the external
6647 This phase uses the Linux kernel's Makefile in order to install the external
6651 It is possible and useful to specify the Linux kernel to use for building
6652 the module (in the "arguments" form of a package using the
6653 linux-module-build-system, use the key #:linux to specify it).
6656 @defvr {Scheme Variable} node-build-system
6657 This variable is exported by @code{(guix build-system node)}. It
6658 implements the build procedure used by @uref{http://nodejs.org,
6659 Node.js}, which implements an approximation of the @code{npm install}
6660 command, followed by an @code{npm test} command.
6662 Which Node.js package is used to interpret the @code{npm} commands can
6663 be specified with the @code{#:node} parameter which defaults to
6667 Lastly, for packages that do not need anything as sophisticated, a
6668 ``trivial'' build system is provided. It is trivial in the sense that
6669 it provides basically no support: it does not pull any implicit inputs,
6670 and does not have a notion of build phases.
6672 @defvr {Scheme Variable} trivial-build-system
6673 This variable is exported by @code{(guix build-system trivial)}.
6675 This build system requires a @code{#:builder} argument. This argument
6676 must be a Scheme expression that builds the package output(s)---as
6677 with @code{build-expression->derivation} (@pxref{Derivations,
6678 @code{build-expression->derivation}}).
6688 Conceptually, the @dfn{store} is the place where derivations that have
6689 been built successfully are stored---by default, @file{/gnu/store}.
6690 Sub-directories in the store are referred to as @dfn{store items} or
6691 sometimes @dfn{store paths}. The store has an associated database that
6692 contains information such as the store paths referred to by each store
6693 path, and the list of @emph{valid} store items---results of successful
6694 builds. This database resides in @file{@var{localstatedir}/guix/db},
6695 where @var{localstatedir} is the state directory specified @i{via}
6696 @option{--localstatedir} at configure time, usually @file{/var}.
6698 The store is @emph{always} accessed by the daemon on behalf of its clients
6699 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6700 connect to the daemon over a Unix-domain socket, send requests to it,
6701 and read the result---these are remote procedure calls, or RPCs.
6704 Users must @emph{never} modify files under @file{/gnu/store} directly.
6705 This would lead to inconsistencies and break the immutability
6706 assumptions of Guix's functional model (@pxref{Introduction}).
6708 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6709 how to check the integrity of the store and attempt recovery from
6710 accidental modifications.
6713 The @code{(guix store)} module provides procedures to connect to the
6714 daemon, and to perform RPCs. These are described below. By default,
6715 @code{open-connection}, and thus all the @command{guix} commands,
6716 connect to the local daemon or to the URI specified by the
6717 @code{GUIX_DAEMON_SOCKET} environment variable.
6719 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6720 When set, the value of this variable should be a file name or a URI
6721 designating the daemon endpoint. When it is a file name, it denotes a
6722 Unix-domain socket to connect to. In addition to file names, the
6723 supported URI schemes are:
6728 These are for Unix-domain sockets.
6729 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6730 @file{/var/guix/daemon-socket/socket}.
6733 @cindex daemon, remote access
6734 @cindex remote access to the daemon
6735 @cindex daemon, cluster setup
6736 @cindex clusters, daemon setup
6737 These URIs denote connections over TCP/IP, without encryption nor
6738 authentication of the remote host. The URI must specify the host name
6739 and optionally a port number (by default port 44146 is used):
6742 guix://master.guix.example.org:1234
6745 This setup is suitable on local networks, such as clusters, where only
6746 trusted nodes may connect to the build daemon at
6747 @code{master.guix.example.org}.
6749 The @code{--listen} option of @command{guix-daemon} can be used to
6750 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6754 @cindex SSH access to build daemons
6755 These URIs allow you to connect to a remote daemon over
6756 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6757 A typical URL might look like this:
6760 ssh://charlie@@guix.example.org:22
6763 As for @command{guix copy}, the usual OpenSSH client configuration files
6764 are honored (@pxref{Invoking guix copy}).
6767 Additional URI schemes may be supported in the future.
6769 @c XXX: Remove this note when the protocol incurs fewer round trips
6770 @c and when (guix derivations) no longer relies on file system access.
6772 The ability to connect to remote build daemons is considered
6773 experimental as of @value{VERSION}. Please get in touch with us to
6774 share any problems or suggestions you may have (@pxref{Contributing}).
6778 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6779 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6780 @var{reserve-space?} is true, instruct it to reserve a little bit of
6781 extra space on the file system so that the garbage collector can still
6782 operate should the disk become full. Return a server object.
6784 @var{file} defaults to @code{%default-socket-path}, which is the normal
6785 location given the options that were passed to @command{configure}.
6788 @deffn {Scheme Procedure} close-connection @var{server}
6789 Close the connection to @var{server}.
6792 @defvr {Scheme Variable} current-build-output-port
6793 This variable is bound to a SRFI-39 parameter, which refers to the port
6794 where build and error logs sent by the daemon should be written.
6797 Procedures that make RPCs all take a server object as their first
6800 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6801 @cindex invalid store items
6802 Return @code{#t} when @var{path} designates a valid store item and
6803 @code{#f} otherwise (an invalid item may exist on disk but still be
6804 invalid, for instance because it is the result of an aborted or failed
6807 A @code{&store-protocol-error} condition is raised if @var{path} is not
6808 prefixed by the store directory (@file{/gnu/store}).
6811 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6812 Add @var{text} under file @var{name} in the store, and return its store
6813 path. @var{references} is the list of store paths referred to by the
6814 resulting store path.
6817 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6819 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6820 file names, or derivation/output pairs, using the specified
6821 @var{mode}---@code{(build-mode normal)} by default.
6824 Note that the @code{(guix monads)} module provides a monad as well as
6825 monadic versions of the above procedures, with the goal of making it
6826 more convenient to work with code that accesses the store (@pxref{The
6830 @i{This section is currently incomplete.}
6833 @section Derivations
6836 Low-level build actions and the environment in which they are performed
6837 are represented by @dfn{derivations}. A derivation contains the
6838 following pieces of information:
6842 The outputs of the derivation---derivations produce at least one file or
6843 directory in the store, but may produce more.
6846 @cindex build-time dependencies
6847 @cindex dependencies, build-time
6848 The inputs of the derivations---i.e., its build-time dependencies---which may
6849 be other derivations or plain files in the store (patches, build scripts,
6853 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6856 The file name of a build script in the store, along with the arguments
6860 A list of environment variables to be defined.
6864 @cindex derivation path
6865 Derivations allow clients of the daemon to communicate build actions to
6866 the store. They exist in two forms: as an in-memory representation,
6867 both on the client- and daemon-side, and as files in the store whose
6868 name end in @code{.drv}---these files are referred to as @dfn{derivation
6869 paths}. Derivations paths can be passed to the @code{build-derivations}
6870 procedure to perform the build actions they prescribe (@pxref{The
6873 @cindex fixed-output derivations
6874 Operations such as file downloads and version-control checkouts for
6875 which the expected content hash is known in advance are modeled as
6876 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6877 of a fixed-output derivation are independent of its inputs---e.g., a
6878 source code download produces the same result regardless of the download
6879 method and tools being used.
6882 @cindex run-time dependencies
6883 @cindex dependencies, run-time
6884 The outputs of derivations---i.e., the build results---have a set of
6885 @dfn{references}, as reported by the @code{references} RPC or the
6886 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6887 are the set of run-time dependencies of the build results. References are a
6888 subset of the inputs of the derivation; this subset is automatically computed
6889 by the build daemon by scanning all the files in the outputs.
6891 The @code{(guix derivations)} module provides a representation of
6892 derivations as Scheme objects, along with procedures to create and
6893 otherwise manipulate derivations. The lowest-level primitive to create
6894 a derivation is the @code{derivation} procedure:
6896 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6897 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6898 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6899 [#:system (%current-system)] [#:references-graphs #f] @
6900 [#:allowed-references #f] [#:disallowed-references #f] @
6901 [#:leaked-env-vars #f] [#:local-build? #f] @
6902 [#:substitutable? #t] [#:properties '()]
6903 Build a derivation with the given arguments, and return the resulting
6904 @code{<derivation>} object.
6906 When @var{hash} and @var{hash-algo} are given, a
6907 @dfn{fixed-output derivation} is created---i.e., one whose result is
6908 known in advance, such as a file download. If, in addition,
6909 @var{recursive?} is true, then that fixed output may be an executable
6910 file or a directory and @var{hash} must be the hash of an archive
6911 containing this output.
6913 When @var{references-graphs} is true, it must be a list of file
6914 name/store path pairs. In that case, the reference graph of each store
6915 path is exported in the build environment in the corresponding file, in
6916 a simple text format.
6918 When @var{allowed-references} is true, it must be a list of store items
6919 or outputs that the derivation's output may refer to. Likewise,
6920 @var{disallowed-references}, if true, must be a list of things the
6921 outputs may @emph{not} refer to.
6923 When @var{leaked-env-vars} is true, it must be a list of strings
6924 denoting environment variables that are allowed to ``leak'' from the
6925 daemon's environment to the build environment. This is only applicable
6926 to fixed-output derivations---i.e., when @var{hash} is true. The main
6927 use is to allow variables such as @code{http_proxy} to be passed to
6928 derivations that download files.
6930 When @var{local-build?} is true, declare that the derivation is not a
6931 good candidate for offloading and should rather be built locally
6932 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6933 where the costs of data transfers would outweigh the benefits.
6935 When @var{substitutable?} is false, declare that substitutes of the
6936 derivation's output should not be used (@pxref{Substitutes}). This is
6937 useful, for instance, when building packages that capture details of the
6938 host CPU instruction set.
6940 @var{properties} must be an association list describing ``properties'' of the
6941 derivation. It is kept as-is, uninterpreted, in the derivation.
6945 Here's an example with a shell script as its builder, assuming
6946 @var{store} is an open connection to the daemon, and @var{bash} points
6947 to a Bash executable in the store:
6950 (use-modules (guix utils)
6954 (let ((builder ; add the Bash script to the store
6955 (add-text-to-store store "my-builder.sh"
6956 "echo hello world > $out\n" '())))
6957 (derivation store "foo"
6958 bash `("-e" ,builder)
6959 #:inputs `((,bash) (,builder))
6960 #:env-vars '(("HOME" . "/homeless"))))
6961 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6964 As can be guessed, this primitive is cumbersome to use directly. A
6965 better approach is to write build scripts in Scheme, of course! The
6966 best course of action for that is to write the build code as a
6967 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6968 information, @pxref{G-Expressions}.
6970 Once upon a time, @code{gexp->derivation} did not exist and constructing
6971 derivations with build code written in Scheme was achieved with
6972 @code{build-expression->derivation}, documented below. This procedure
6973 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6975 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6976 @var{name} @var{exp} @
6977 [#:system (%current-system)] [#:inputs '()] @
6978 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6979 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6980 [#:references-graphs #f] [#:allowed-references #f] @
6981 [#:disallowed-references #f] @
6982 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6983 Return a derivation that executes Scheme expression @var{exp} as a
6984 builder for derivation @var{name}. @var{inputs} must be a list of
6985 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6986 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6987 modules from the current search path to be copied in the store,
6988 compiled, and made available in the load path during the execution of
6989 @var{exp}---e.g., @code{((guix build utils) (guix build
6990 gnu-build-system))}.
6992 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6993 to a list of output/path pairs, and where @code{%build-inputs} is bound
6994 to a list of string/output-path pairs made from @var{inputs}.
6995 Optionally, @var{env-vars} is a list of string pairs specifying the name
6996 and value of environment variables visible to the builder. The builder
6997 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6998 @var{exp} returns @code{#f}, the build is considered to have failed.
7000 @var{exp} is built using @var{guile-for-build} (a derivation). When
7001 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7002 @code{%guile-for-build} fluid is used instead.
7004 See the @code{derivation} procedure for the meaning of
7005 @var{references-graphs}, @var{allowed-references},
7006 @var{disallowed-references}, @var{local-build?}, and
7007 @var{substitutable?}.
7011 Here's an example of a single-output derivation that creates a directory
7012 containing one file:
7015 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7016 (mkdir out) ; create /gnu/store/@dots{}-goo
7017 (call-with-output-file (string-append out "/test")
7019 (display '(hello guix) p))))))
7020 (build-expression->derivation store "goo" builder))
7022 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7026 @node The Store Monad
7027 @section The Store Monad
7031 The procedures that operate on the store described in the previous
7032 sections all take an open connection to the build daemon as their first
7033 argument. Although the underlying model is functional, they either have
7034 side effects or depend on the current state of the store.
7036 The former is inconvenient: the connection to the build daemon has to be
7037 carried around in all those functions, making it impossible to compose
7038 functions that do not take that parameter with functions that do. The
7039 latter can be problematic: since store operations have side effects
7040 and/or depend on external state, they have to be properly sequenced.
7042 @cindex monadic values
7043 @cindex monadic functions
7044 This is where the @code{(guix monads)} module comes in. This module
7045 provides a framework for working with @dfn{monads}, and a particularly
7046 useful monad for our uses, the @dfn{store monad}. Monads are a
7047 construct that allows two things: associating ``context'' with values
7048 (in our case, the context is the store), and building sequences of
7049 computations (here computations include accesses to the store). Values
7050 in a monad---values that carry this additional context---are called
7051 @dfn{monadic values}; procedures that return such values are called
7052 @dfn{monadic procedures}.
7054 Consider this ``normal'' procedure:
7057 (define (sh-symlink store)
7058 ;; Return a derivation that symlinks the 'bash' executable.
7059 (let* ((drv (package-derivation store bash))
7060 (out (derivation->output-path drv))
7061 (sh (string-append out "/bin/bash")))
7062 (build-expression->derivation store "sh"
7063 `(symlink ,sh %output))))
7066 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7067 as a monadic function:
7070 (define (sh-symlink)
7071 ;; Same, but return a monadic value.
7072 (mlet %store-monad ((drv (package->derivation bash)))
7073 (gexp->derivation "sh"
7074 #~(symlink (string-append #$drv "/bin/bash")
7078 There are several things to note in the second version: the @code{store}
7079 parameter is now implicit and is ``threaded'' in the calls to the
7080 @code{package->derivation} and @code{gexp->derivation} monadic
7081 procedures, and the monadic value returned by @code{package->derivation}
7082 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7084 As it turns out, the call to @code{package->derivation} can even be
7085 omitted since it will take place implicitly, as we will see later
7086 (@pxref{G-Expressions}):
7089 (define (sh-symlink)
7090 (gexp->derivation "sh"
7091 #~(symlink (string-append #$bash "/bin/bash")
7096 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7097 @c for the funny quote.
7098 Calling the monadic @code{sh-symlink} has no effect. As someone once
7099 said, ``you exit a monad like you exit a building on fire: by running''.
7100 So, to exit the monad and get the desired effect, one must use
7101 @code{run-with-store}:
7104 (run-with-store (open-connection) (sh-symlink))
7105 @result{} /gnu/store/...-sh-symlink
7108 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7109 new ``meta-commands'' to make it easier to deal with monadic procedures:
7110 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7111 to ``run'' a single monadic value through the store:
7114 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7115 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7118 The latter enters a recursive REPL, where all the return values are
7119 automatically run through the store:
7122 scheme@@(guile-user)> ,enter-store-monad
7123 store-monad@@(guile-user) [1]> (package->derivation hello)
7124 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7125 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7126 $3 = "/gnu/store/@dots{}-foo"
7127 store-monad@@(guile-user) [1]> ,q
7128 scheme@@(guile-user)>
7132 Note that non-monadic values cannot be returned in the
7133 @code{store-monad} REPL.
7135 The main syntactic forms to deal with monads in general are provided by
7136 the @code{(guix monads)} module and are described below.
7138 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7139 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7143 @deffn {Scheme Syntax} return @var{val}
7144 Return a monadic value that encapsulates @var{val}.
7147 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7148 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7149 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7150 referred to as ``bind'', but that name denotes an unrelated procedure in
7151 Guile. Thus we use this somewhat cryptic symbol inherited from the
7152 Haskell language.}. There can be one @var{mproc} or several of them, as
7157 (with-monad %state-monad
7159 (lambda (x) (return (+ 1 x)))
7160 (lambda (x) (return (* 2 x)))))
7164 @result{} some-state
7168 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7170 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7172 Bind the variables @var{var} to the monadic values @var{mval} in
7173 @var{body}, which is a sequence of expressions. As with the bind
7174 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7175 value ``contained'' in @var{mval} and making @var{var} refer to that
7176 raw, non-monadic value within the scope of the @var{body}. The form
7177 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7178 @var{val}, as per @code{let}. The binding operations occur in sequence
7179 from left to right. The last expression of @var{body} must be a monadic
7180 expression, and its result will become the result of the @code{mlet} or
7181 @code{mlet*} when run in the @var{monad}.
7183 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7184 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7187 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7188 Bind @var{mexp} and the following monadic expressions in sequence,
7189 returning the result of the last expression. Every expression in the
7190 sequence must be a monadic expression.
7192 This is akin to @code{mlet}, except that the return values of the
7193 monadic expressions are ignored. In that sense, it is analogous to
7194 @code{begin}, but applied to monadic expressions.
7197 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7198 When @var{condition} is true, evaluate the sequence of monadic
7199 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7200 @var{condition} is false, return @code{*unspecified*} in the current
7201 monad. Every expression in the sequence must be a monadic expression.
7204 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7205 When @var{condition} is false, evaluate the sequence of monadic
7206 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7207 @var{condition} is true, return @code{*unspecified*} in the current
7208 monad. Every expression in the sequence must be a monadic expression.
7212 The @code{(guix monads)} module provides the @dfn{state monad}, which
7213 allows an additional value---the state---to be @emph{threaded} through
7214 monadic procedure calls.
7216 @defvr {Scheme Variable} %state-monad
7217 The state monad. Procedures in the state monad can access and change
7218 the state that is threaded.
7220 Consider the example below. The @code{square} procedure returns a value
7221 in the state monad. It returns the square of its argument, but also
7222 increments the current state value:
7226 (mlet %state-monad ((count (current-state)))
7227 (mbegin %state-monad
7228 (set-current-state (+ 1 count))
7231 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7236 When ``run'' through @var{%state-monad}, we obtain that additional state
7237 value, which is the number of @code{square} calls.
7240 @deffn {Monadic Procedure} current-state
7241 Return the current state as a monadic value.
7244 @deffn {Monadic Procedure} set-current-state @var{value}
7245 Set the current state to @var{value} and return the previous state as a
7249 @deffn {Monadic Procedure} state-push @var{value}
7250 Push @var{value} to the current state, which is assumed to be a list,
7251 and return the previous state as a monadic value.
7254 @deffn {Monadic Procedure} state-pop
7255 Pop a value from the current state and return it as a monadic value.
7256 The state is assumed to be a list.
7259 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7260 Run monadic value @var{mval} starting with @var{state} as the initial
7261 state. Return two values: the resulting value, and the resulting state.
7264 The main interface to the store monad, provided by the @code{(guix
7265 store)} module, is as follows.
7267 @defvr {Scheme Variable} %store-monad
7268 The store monad---an alias for @var{%state-monad}.
7270 Values in the store monad encapsulate accesses to the store. When its
7271 effect is needed, a value of the store monad must be ``evaluated'' by
7272 passing it to the @code{run-with-store} procedure (see below.)
7275 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7276 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7277 open store connection.
7280 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7281 Return as a monadic value the absolute file name in the store of the file
7282 containing @var{text}, a string. @var{references} is a list of store items that the
7283 resulting text file refers to; it defaults to the empty list.
7286 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7287 Return as a monadic value the absolute file name in the store of the file
7288 containing @var{data}, a bytevector. @var{references} is a list of store
7289 items that the resulting binary file refers to; it defaults to the empty list.
7292 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7293 [#:recursive? #t] [#:select? (const #t)]
7294 Return the name of @var{file} once interned in the store. Use
7295 @var{name} as its store name, or the basename of @var{file} if
7296 @var{name} is omitted.
7298 When @var{recursive?} is true, the contents of @var{file} are added
7299 recursively; if @var{file} designates a flat file and @var{recursive?}
7300 is true, its contents are added, and its permission bits are kept.
7302 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7303 @var{stat})} for each directory entry, where @var{file} is the entry's
7304 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7305 entries for which @var{select?} does not return true.
7307 The example below adds a file to the store, under two different names:
7310 (run-with-store (open-connection)
7311 (mlet %store-monad ((a (interned-file "README"))
7312 (b (interned-file "README" "LEGU-MIN")))
7313 (return (list a b))))
7315 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7320 The @code{(guix packages)} module exports the following package-related
7323 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7324 [#:system (%current-system)] [#:target #f] @
7327 value in the absolute file name of @var{file} within the @var{output}
7328 directory of @var{package}. When @var{file} is omitted, return the name
7329 of the @var{output} directory of @var{package}. When @var{target} is
7330 true, use it as a cross-compilation target triplet.
7333 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7334 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7335 @var{target} [@var{system}]
7336 Monadic version of @code{package-derivation} and
7337 @code{package-cross-derivation} (@pxref{Defining Packages}).
7342 @section G-Expressions
7344 @cindex G-expression
7345 @cindex build code quoting
7346 So we have ``derivations'', which represent a sequence of build actions
7347 to be performed to produce an item in the store (@pxref{Derivations}).
7348 These build actions are performed when asking the daemon to actually
7349 build the derivations; they are run by the daemon in a container
7350 (@pxref{Invoking guix-daemon}).
7352 @cindex strata of code
7353 It should come as no surprise that we like to write these build actions
7354 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7355 code@footnote{The term @dfn{stratum} in this context was coined by
7356 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7357 Kiselyov, who has written insightful
7358 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7359 on this topic}, refers to this kind of code generation as
7360 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7361 to the daemon, etc.---and the ``build code''---code that actually
7362 performs build actions, such as making directories, invoking
7363 @command{make}, etc.
7365 To describe a derivation and its build actions, one typically needs to
7366 embed build code inside host code. It boils down to manipulating build
7367 code as data, and the homoiconicity of Scheme---code has a direct
7368 representation as data---comes in handy for that. But we need more than
7369 the normal @code{quasiquote} mechanism in Scheme to construct build
7372 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7373 S-expressions adapted to build expressions. G-expressions, or
7374 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7375 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7376 @code{#$}, and @code{#$@@}), which are comparable to
7377 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7378 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7379 GNU Guile Reference Manual}). However, there are major differences:
7383 Gexps are meant to be written to a file and run or manipulated by other
7387 When a high-level object such as a package or derivation is unquoted
7388 inside a gexp, the result is as if its output file name had been
7392 Gexps carry information about the packages or derivations they refer to,
7393 and these dependencies are automatically added as inputs to the build
7394 processes that use them.
7397 @cindex lowering, of high-level objects in gexps
7398 This mechanism is not limited to package and derivation
7399 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7400 derivations or files in the store can be defined,
7401 such that these objects can also be inserted
7402 into gexps. For example, a useful type of high-level objects that can be
7403 inserted in a gexp is ``file-like objects'', which make it easy to
7404 add files to the store and to refer to them in
7405 derivations and such (see @code{local-file} and @code{plain-file}
7408 To illustrate the idea, here is an example of a gexp:
7415 (symlink (string-append #$coreutils "/bin/ls")
7419 This gexp can be passed to @code{gexp->derivation}; we obtain a
7420 derivation that builds a directory containing exactly one symlink to
7421 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7424 (gexp->derivation "the-thing" build-exp)
7427 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7428 substituted to the reference to the @var{coreutils} package in the
7429 actual build code, and @var{coreutils} is automatically made an input to
7430 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7431 output)}) is replaced by a string containing the directory name of the
7432 output of the derivation.
7434 @cindex cross compilation
7435 In a cross-compilation context, it is useful to distinguish between
7436 references to the @emph{native} build of a package---that can run on the
7437 host---versus references to cross builds of a package. To that end, the
7438 @code{#+} plays the same role as @code{#$}, but is a reference to a
7439 native package build:
7442 (gexp->derivation "vi"
7445 (system* (string-append #+coreutils "/bin/ln")
7447 (string-append #$emacs "/bin/emacs")
7448 (string-append #$output "/bin/vi")))
7449 #:target "mips64el-linux-gnu")
7453 In the example above, the native build of @var{coreutils} is used, so
7454 that @command{ln} can actually run on the host; but then the
7455 cross-compiled build of @var{emacs} is referenced.
7457 @cindex imported modules, for gexps
7458 @findex with-imported-modules
7459 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7460 able to use certain Guile modules from the ``host environment'' in the
7461 gexp, so those modules should be imported in the ``build environment''.
7462 The @code{with-imported-modules} form allows you to express that:
7465 (let ((build (with-imported-modules '((guix build utils))
7467 (use-modules (guix build utils))
7468 (mkdir-p (string-append #$output "/bin"))))))
7469 (gexp->derivation "empty-dir"
7472 (display "success!\n")
7477 In this example, the @code{(guix build utils)} module is automatically
7478 pulled into the isolated build environment of our gexp, such that
7479 @code{(use-modules (guix build utils))} works as expected.
7481 @cindex module closure
7482 @findex source-module-closure
7483 Usually you want the @emph{closure} of the module to be imported---i.e.,
7484 the module itself and all the modules it depends on---rather than just
7485 the module; failing to do that, attempts to use the module will fail
7486 because of missing dependent modules. The @code{source-module-closure}
7487 procedure computes the closure of a module by looking at its source file
7488 headers, which comes in handy in this case:
7491 (use-modules (guix modules)) ;for 'source-module-closure'
7493 (with-imported-modules (source-module-closure
7494 '((guix build utils)
7496 (gexp->derivation "something-with-vms"
7498 (use-modules (guix build utils)
7503 @cindex extensions, for gexps
7504 @findex with-extensions
7505 In the same vein, sometimes you want to import not just pure-Scheme
7506 modules, but also ``extensions'' such as Guile bindings to C libraries
7507 or other ``full-blown'' packages. Say you need the @code{guile-json}
7508 package available on the build side, here's how you would do it:
7511 (use-modules (gnu packages guile)) ;for 'guile-json'
7513 (with-extensions (list guile-json)
7514 (gexp->derivation "something-with-json"
7516 (use-modules (json))
7520 The syntactic form to construct gexps is summarized below.
7522 @deffn {Scheme Syntax} #~@var{exp}
7523 @deffnx {Scheme Syntax} (gexp @var{exp})
7524 Return a G-expression containing @var{exp}. @var{exp} may contain one
7525 or more of the following forms:
7529 @itemx (ungexp @var{obj})
7530 Introduce a reference to @var{obj}. @var{obj} may have one of the
7531 supported types, for example a package or a
7532 derivation, in which case the @code{ungexp} form is replaced by its
7533 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7535 If @var{obj} is a list, it is traversed and references to supported
7536 objects are substituted similarly.
7538 If @var{obj} is another gexp, its contents are inserted and its
7539 dependencies are added to those of the containing gexp.
7541 If @var{obj} is another kind of object, it is inserted as is.
7543 @item #$@var{obj}:@var{output}
7544 @itemx (ungexp @var{obj} @var{output})
7545 This is like the form above, but referring explicitly to the
7546 @var{output} of @var{obj}---this is useful when @var{obj} produces
7547 multiple outputs (@pxref{Packages with Multiple Outputs}).
7550 @itemx #+@var{obj}:output
7551 @itemx (ungexp-native @var{obj})
7552 @itemx (ungexp-native @var{obj} @var{output})
7553 Same as @code{ungexp}, but produces a reference to the @emph{native}
7554 build of @var{obj} when used in a cross compilation context.
7556 @item #$output[:@var{output}]
7557 @itemx (ungexp output [@var{output}])
7558 Insert a reference to derivation output @var{output}, or to the main
7559 output when @var{output} is omitted.
7561 This only makes sense for gexps passed to @code{gexp->derivation}.
7564 @itemx (ungexp-splicing @var{lst})
7565 Like the above, but splices the contents of @var{lst} inside the
7569 @itemx (ungexp-native-splicing @var{lst})
7570 Like the above, but refers to native builds of the objects listed in
7575 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7576 of the @code{gexp?} type (see below.)
7579 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7580 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7581 in their execution environment.
7583 Each item in @var{modules} can be the name of a module, such as
7584 @code{(guix build utils)}, or it can be a module name, followed by an
7585 arrow, followed by a file-like object:
7588 `((guix build utils)
7590 ((guix config) => ,(scheme-file "config.scm"
7591 #~(define-module @dots{}))))
7595 In the example above, the first two modules are taken from the search
7596 path, and the last one is created from the given file-like object.
7598 This form has @emph{lexical} scope: it has an effect on the gexps
7599 directly defined in @var{body}@dots{}, but not on those defined, say, in
7600 procedures called from @var{body}@dots{}.
7603 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7604 Mark the gexps defined in @var{body}@dots{} as requiring
7605 @var{extensions} in their build and execution environment.
7606 @var{extensions} is typically a list of package objects such as those
7607 defined in the @code{(gnu packages guile)} module.
7609 Concretely, the packages listed in @var{extensions} are added to the
7610 load path while compiling imported modules in @var{body}@dots{}; they
7611 are also added to the load path of the gexp returned by
7615 @deffn {Scheme Procedure} gexp? @var{obj}
7616 Return @code{#t} if @var{obj} is a G-expression.
7619 G-expressions are meant to be written to disk, either as code building
7620 some derivation, or as plain files in the store. The monadic procedures
7621 below allow you to do that (@pxref{The Store Monad}, for more
7622 information about monads.)
7624 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7625 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7626 [#:hash #f] [#:hash-algo #f] @
7627 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7628 [#:module-path @var{%load-path}] @
7629 [#:effective-version "2.2"] @
7630 [#:references-graphs #f] [#:allowed-references #f] @
7631 [#:disallowed-references #f] @
7632 [#:leaked-env-vars #f] @
7633 [#:script-name (string-append @var{name} "-builder")] @
7634 [#:deprecation-warnings #f] @
7635 [#:local-build? #f] [#:substitutable? #t] @
7636 [#:properties '()] [#:guile-for-build #f]
7637 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7638 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7639 stored in a file called @var{script-name}. When @var{target} is true,
7640 it is used as the cross-compilation target triplet for packages referred
7643 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7645 make @var{modules} available in the evaluation context of @var{exp};
7646 @var{modules} is a list of names of Guile modules searched in
7647 @var{module-path} to be copied in the store, compiled, and made available in
7648 the load path during the execution of @var{exp}---e.g., @code{((guix
7649 build utils) (guix build gnu-build-system))}.
7651 @var{effective-version} determines the string to use when adding extensions of
7652 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7654 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7657 When @var{references-graphs} is true, it must be a list of tuples of one of the
7661 (@var{file-name} @var{package})
7662 (@var{file-name} @var{package} @var{output})
7663 (@var{file-name} @var{derivation})
7664 (@var{file-name} @var{derivation} @var{output})
7665 (@var{file-name} @var{store-item})
7668 The right-hand-side of each element of @var{references-graphs} is automatically made
7669 an input of the build process of @var{exp}. In the build environment, each
7670 @var{file-name} contains the reference graph of the corresponding item, in a simple
7673 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7674 In the latter case, the list denotes store items that the result is allowed to
7675 refer to. Any reference to another store item will lead to a build error.
7676 Similarly for @var{disallowed-references}, which can list items that must not be
7677 referenced by the outputs.
7679 @var{deprecation-warnings} determines whether to show deprecation warnings while
7680 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7682 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7685 @cindex file-like objects
7686 The @code{local-file}, @code{plain-file}, @code{computed-file},
7687 @code{program-file}, and @code{scheme-file} procedures below return
7688 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7689 these objects lead to a file in the store. Consider this G-expression:
7692 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7693 #$(local-file "/tmp/my-nscd.conf"))
7696 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7697 to the store. Once expanded, for instance @i{via}
7698 @code{gexp->derivation}, the G-expression refers to that copy under
7699 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7700 does not have any effect on what the G-expression does.
7701 @code{plain-file} can be used similarly; it differs in that the file
7702 content is directly passed as a string.
7704 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7705 [#:recursive? #f] [#:select? (const #t)]
7706 Return an object representing local file @var{file} to add to the store;
7707 this object can be used in a gexp. If @var{file} is a literal string
7708 denoting a relative file name, it is looked up relative to the source
7709 file where it appears; if @var{file} is not a literal string, it is
7710 looked up relative to the current working directory at run time.
7711 @var{file} will be added to the store under @var{name}--by default the
7712 base name of @var{file}.
7714 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7715 designates a flat file and @var{recursive?} is true, its contents are added, and its
7716 permission bits are kept.
7718 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7719 @var{stat})} for each directory entry, where @var{file} is the entry's
7720 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7721 entries for which @var{select?} does not return true.
7723 This is the declarative counterpart of the @code{interned-file} monadic
7724 procedure (@pxref{The Store Monad, @code{interned-file}}).
7727 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7728 Return an object representing a text file called @var{name} with the given
7729 @var{content} (a string or a bytevector) to be added to the store.
7731 This is the declarative counterpart of @code{text-file}.
7734 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7735 [#:options '(#:local-build? #t)]
7736 Return an object representing the store item @var{name}, a file or
7737 directory computed by @var{gexp}. @var{options}
7738 is a list of additional arguments to pass to @code{gexp->derivation}.
7740 This is the declarative counterpart of @code{gexp->derivation}.
7743 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7744 [#:guile (default-guile)] [#:module-path %load-path] @
7745 [#:system (%current-system)] [#:target #f]
7746 Return an executable script @var{name} that runs @var{exp} using
7747 @var{guile}, with @var{exp}'s imported modules in its search path.
7748 Look up @var{exp}'s modules in @var{module-path}.
7750 The example below builds a script that simply invokes the @command{ls}
7754 (use-modules (guix gexp) (gnu packages base))
7756 (gexp->script "list-files"
7757 #~(execl #$(file-append coreutils "/bin/ls")
7761 When ``running'' it through the store (@pxref{The Store Monad,
7762 @code{run-with-store}}), we obtain a derivation that produces an
7763 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7766 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7768 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7772 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7773 [#:guile #f] [#:module-path %load-path]
7774 Return an object representing the executable store item @var{name} that
7775 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7776 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7778 This is the declarative counterpart of @code{gexp->script}.
7781 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7782 [#:set-load-path? #t] [#:module-path %load-path] @
7784 [#:guile (default-guile)]
7785 Return a derivation that builds a file @var{name} containing @var{exp}.
7786 When @var{splice?} is true, @var{exp} is considered to be a list of
7787 expressions that will be spliced in the resulting file.
7789 When @var{set-load-path?} is true, emit code in the resulting file to
7790 set @code{%load-path} and @code{%load-compiled-path} to honor
7791 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7794 The resulting file holds references to all the dependencies of @var{exp}
7795 or a subset thereof.
7798 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7799 Return an object representing the Scheme file @var{name} that contains
7802 This is the declarative counterpart of @code{gexp->file}.
7805 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7806 Return as a monadic value a derivation that builds a text file
7807 containing all of @var{text}. @var{text} may list, in addition to
7808 strings, objects of any type that can be used in a gexp: packages,
7809 derivations, local file objects, etc. The resulting store file holds
7810 references to all these.
7812 This variant should be preferred over @code{text-file} anytime the file
7813 to create will reference items from the store. This is typically the
7814 case when building a configuration file that embeds store file names,
7818 (define (profile.sh)
7819 ;; Return the name of a shell script in the store that
7820 ;; initializes the 'PATH' environment variable.
7821 (text-file* "profile.sh"
7822 "export PATH=" coreutils "/bin:"
7823 grep "/bin:" sed "/bin\n"))
7826 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7827 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7828 preventing them from being garbage-collected during its lifetime.
7831 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7832 Return an object representing store file @var{name} containing
7833 @var{text}. @var{text} is a sequence of strings and file-like objects,
7837 (mixed-text-file "profile"
7838 "export PATH=" coreutils "/bin:" grep "/bin")
7841 This is the declarative counterpart of @code{text-file*}.
7844 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7845 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7846 Each item in @var{files} must be a two-element list where the first element is the
7847 file name to use in the new directory, and the second element is a gexp
7848 denoting the target file. Here's an example:
7852 `(("hosts" ,(plain-file "hosts"
7853 "127.0.0.1 localhost"))
7854 ("bashrc" ,(plain-file "bashrc"
7855 "alias ls='ls --color=auto'"))))
7858 This yields an @code{etc} directory containing these two files.
7861 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7862 Return a directory that is the union of @var{things}, where @var{things} is a list of
7863 file-like objects denoting directories. For example:
7866 (directory-union "guile+emacs" (list guile emacs))
7869 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7872 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7873 Return a file-like object that expands to the concatenation of @var{obj}
7874 and @var{suffix}, where @var{obj} is a lowerable object and each
7875 @var{suffix} is a string.
7877 As an example, consider this gexp:
7880 (gexp->script "run-uname"
7881 #~(system* #$(file-append coreutils
7885 The same effect could be achieved with:
7888 (gexp->script "run-uname"
7889 #~(system* (string-append #$coreutils
7893 There is one difference though: in the @code{file-append} case, the
7894 resulting script contains the absolute file name as a string, whereas in
7895 the second case, the resulting script contains a @code{(string-append
7896 @dots{})} expression to construct the file name @emph{at run time}.
7900 Of course, in addition to gexps embedded in ``host'' code, there are
7901 also modules containing build tools. To make it clear that they are
7902 meant to be used in the build stratum, these modules are kept in the
7903 @code{(guix build @dots{})} name space.
7905 @cindex lowering, of high-level objects in gexps
7906 Internally, high-level objects are @dfn{lowered}, using their compiler,
7907 to either derivations or store items. For instance, lowering a package
7908 yields a derivation, and lowering a @code{plain-file} yields a store
7909 item. This is achieved using the @code{lower-object} monadic procedure.
7911 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7913 Return as a value in @var{%store-monad} the derivation or store item
7914 corresponding to @var{obj} for @var{system}, cross-compiling for
7915 @var{target} if @var{target} is true. @var{obj} must be an object that
7916 has an associated gexp compiler, such as a @code{<package>}.
7919 @node Invoking guix repl
7920 @section Invoking @command{guix repl}
7922 @cindex REPL, read-eval-print loop
7923 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7924 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7925 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7926 command, @command{guix repl} guarantees that all the Guix modules and all its
7927 dependencies are available in the search path. You can use it this way:
7931 scheme@@(guile-user)> ,use (gnu packages base)
7932 scheme@@(guile-user)> coreutils
7933 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7937 In addition, @command{guix repl} implements a simple machine-readable REPL
7938 protocol for use by @code{(guix inferior)}, a facility to interact with
7939 @dfn{inferiors}, separate processes running a potentially different revision
7942 The available options are as follows:
7945 @item --type=@var{type}
7946 @itemx -t @var{type}
7947 Start a REPL of the given @var{TYPE}, which can be one of the following:
7951 This is default, and it spawns a standard full-featured Guile REPL.
7953 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7954 that the @code{(guix inferior)} module speaks.
7957 @item --listen=@var{endpoint}
7958 By default, @command{guix repl} reads from standard input and writes to
7959 standard output. When this option is passed, it will instead listen for
7960 connections on @var{endpoint}. Here are examples of valid options:
7963 @item --listen=tcp:37146
7964 Accept connections on localhost on port 37146.
7966 @item --listen=unix:/tmp/socket
7967 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7971 @c *********************************************************************
7975 This section describes Guix command-line utilities. Some of them are
7976 primarily targeted at developers and users who write new package
7977 definitions, while others are more generally useful. They complement
7978 the Scheme programming interface of Guix in a convenient way.
7981 * Invoking guix build:: Building packages from the command line.
7982 * Invoking guix edit:: Editing package definitions.
7983 * Invoking guix download:: Downloading a file and printing its hash.
7984 * Invoking guix hash:: Computing the cryptographic hash of a file.
7985 * Invoking guix import:: Importing package definitions.
7986 * Invoking guix refresh:: Updating package definitions.
7987 * Invoking guix lint:: Finding errors in package definitions.
7988 * Invoking guix size:: Profiling disk usage.
7989 * Invoking guix graph:: Visualizing the graph of packages.
7990 * Invoking guix publish:: Sharing substitutes.
7991 * Invoking guix challenge:: Challenging substitute servers.
7992 * Invoking guix copy:: Copying to and from a remote store.
7993 * Invoking guix container:: Process isolation.
7994 * Invoking guix weather:: Assessing substitute availability.
7995 * Invoking guix processes:: Listing client processes.
7998 @node Invoking guix build
7999 @section Invoking @command{guix build}
8001 @cindex package building
8002 @cindex @command{guix build}
8003 The @command{guix build} command builds packages or derivations and
8004 their dependencies, and prints the resulting store paths. Note that it
8005 does not modify the user's profile---this is the job of the
8006 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8007 it is mainly useful for distribution developers.
8009 The general syntax is:
8012 guix build @var{options} @var{package-or-derivation}@dots{}
8015 As an example, the following command builds the latest versions of Emacs
8016 and of Guile, displays their build logs, and finally displays the
8017 resulting directories:
8020 guix build emacs guile
8023 Similarly, the following command builds all the available packages:
8026 guix build --quiet --keep-going \
8027 `guix package -A | cut -f1,2 --output-delimiter=@@`
8030 @var{package-or-derivation} may be either the name of a package found in
8031 the software distribution such as @code{coreutils} or
8032 @code{coreutils@@8.20}, or a derivation such as
8033 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8034 package with the corresponding name (and optionally version) is searched
8035 for among the GNU distribution modules (@pxref{Package Modules}).
8037 Alternatively, the @code{--expression} option may be used to specify a
8038 Scheme expression that evaluates to a package; this is useful when
8039 disambiguating among several same-named packages or package variants is
8042 There may be zero or more @var{options}. The available options are
8043 described in the subsections below.
8046 * Common Build Options:: Build options for most commands.
8047 * Package Transformation Options:: Creating variants of packages.
8048 * Additional Build Options:: Options specific to 'guix build'.
8049 * Debugging Build Failures:: Real life packaging experience.
8052 @node Common Build Options
8053 @subsection Common Build Options
8055 A number of options that control the build process are common to
8056 @command{guix build} and other commands that can spawn builds, such as
8057 @command{guix package} or @command{guix archive}. These are the
8062 @item --load-path=@var{directory}
8063 @itemx -L @var{directory}
8064 Add @var{directory} to the front of the package module search path
8065 (@pxref{Package Modules}).
8067 This allows users to define their own packages and make them visible to
8068 the command-line tools.
8072 Keep the build tree of failed builds. Thus, if a build fails, its build
8073 tree is kept under @file{/tmp}, in a directory whose name is shown at
8074 the end of the build log. This is useful when debugging build issues.
8075 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8078 This option implies @option{--no-offload}, and it has no effect when
8079 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8080 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8084 Keep going when some of the derivations fail to build; return only once
8085 all the builds have either completed or failed.
8087 The default behavior is to stop as soon as one of the specified
8088 derivations has failed.
8092 Do not build the derivations.
8094 @anchor{fallback-option}
8096 When substituting a pre-built binary fails, fall back to building
8097 packages locally (@pxref{Substitution Failure}).
8099 @item --substitute-urls=@var{urls}
8100 @anchor{client-substitute-urls}
8101 Consider @var{urls} the whitespace-separated list of substitute source
8102 URLs, overriding the default list of URLs of @command{guix-daemon}
8103 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8105 This means that substitutes may be downloaded from @var{urls}, provided
8106 they are signed by a key authorized by the system administrator
8107 (@pxref{Substitutes}).
8109 When @var{urls} is the empty string, substitutes are effectively
8112 @item --no-substitutes
8113 Do not use substitutes for build products. That is, always build things
8114 locally instead of allowing downloads of pre-built binaries
8115 (@pxref{Substitutes}).
8118 Do not ``graft'' packages. In practice, this means that package updates
8119 available as grafts are not applied. @xref{Security Updates}, for more
8120 information on grafts.
8122 @item --rounds=@var{n}
8123 Build each derivation @var{n} times in a row, and raise an error if
8124 consecutive build results are not bit-for-bit identical.
8126 This is a useful way to detect non-deterministic builds processes.
8127 Non-deterministic build processes are a problem because they make it
8128 practically impossible for users to @emph{verify} whether third-party
8129 binaries are genuine. @xref{Invoking guix challenge}, for more.
8131 Note that, currently, the differing build results are not kept around,
8132 so you will have to manually investigate in case of an error---e.g., by
8133 stashing one of the build results with @code{guix archive --export}
8134 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8138 Do not use offload builds to other machines (@pxref{Daemon Offload
8139 Setup}). That is, always build things locally instead of offloading
8140 builds to remote machines.
8142 @item --max-silent-time=@var{seconds}
8143 When the build or substitution process remains silent for more than
8144 @var{seconds}, terminate it and report a build failure.
8146 By default, the daemon's setting is honored (@pxref{Invoking
8147 guix-daemon, @code{--max-silent-time}}).
8149 @item --timeout=@var{seconds}
8150 Likewise, when the build or substitution process lasts for more than
8151 @var{seconds}, terminate it and report a build failure.
8153 By default, the daemon's setting is honored (@pxref{Invoking
8154 guix-daemon, @code{--timeout}}).
8156 @c Note: This option is actually not part of %standard-build-options but
8157 @c most programs honor it.
8158 @cindex verbosity, of the command-line tools
8159 @cindex build logs, verbosity
8160 @item -v @var{level}
8161 @itemx --verbosity=@var{level}
8162 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8163 output is produced, 1 is for quiet output, and 2 shows all the build log
8164 output on standard error.
8166 @item --cores=@var{n}
8168 Allow the use of up to @var{n} CPU cores for the build. The special
8169 value @code{0} means to use as many CPU cores as available.
8171 @item --max-jobs=@var{n}
8173 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8174 guix-daemon, @code{--max-jobs}}, for details about this option and the
8175 equivalent @command{guix-daemon} option.
8177 @item --debug=@var{level}
8178 Produce debugging output coming from the build daemon. @var{level} must be an
8179 integer between 0 and 5; higher means more verbose output. Setting a level of
8180 4 or more may be helpful when debugging setup issues with the build daemon.
8184 Behind the scenes, @command{guix build} is essentially an interface to
8185 the @code{package-derivation} procedure of the @code{(guix packages)}
8186 module, and to the @code{build-derivations} procedure of the @code{(guix
8187 derivations)} module.
8189 In addition to options explicitly passed on the command line,
8190 @command{guix build} and other @command{guix} commands that support
8191 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8193 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8194 Users can define this variable to a list of command line options that
8195 will automatically be used by @command{guix build} and other
8196 @command{guix} commands that can perform builds, as in the example
8200 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8203 These options are parsed independently, and the result is appended to
8204 the parsed command-line options.
8208 @node Package Transformation Options
8209 @subsection Package Transformation Options
8211 @cindex package variants
8212 Another set of command-line options supported by @command{guix build}
8213 and also @command{guix package} are @dfn{package transformation
8214 options}. These are options that make it possible to define @dfn{package
8215 variants}---for instance, packages built from different source code.
8216 This is a convenient way to create customized packages on the fly
8217 without having to type in the definitions of package variants
8218 (@pxref{Defining Packages}).
8222 @item --with-source=@var{source}
8223 @itemx --with-source=@var{package}=@var{source}
8224 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8225 Use @var{source} as the source of @var{package}, and @var{version} as
8227 @var{source} must be a file name or a URL, as for @command{guix
8228 download} (@pxref{Invoking guix download}).
8230 When @var{package} is omitted,
8231 it is taken to be the package name specified on the
8232 command line that matches the base of @var{source}---e.g.,
8233 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8234 package is @code{guile}.
8236 Likewise, when @var{version} is omitted, the version string is inferred from
8237 @var{source}; in the previous example, it is @code{2.0.10}.
8239 This option allows users to try out versions of packages other than the
8240 one provided by the distribution. The example below downloads
8241 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8242 the @code{ed} package:
8245 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8248 As a developer, @code{--with-source} makes it easy to test release
8252 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8255 @dots{} or to build from a checkout in a pristine environment:
8258 $ git clone git://git.sv.gnu.org/guix.git
8259 $ guix build guix --with-source=guix@@1.0=./guix
8262 @item --with-input=@var{package}=@var{replacement}
8263 Replace dependency on @var{package} by a dependency on
8264 @var{replacement}. @var{package} must be a package name, and
8265 @var{replacement} must be a package specification such as @code{guile}
8266 or @code{guile@@1.8}.
8268 For instance, the following command builds Guix, but replaces its
8269 dependency on the current stable version of Guile with a dependency on
8270 the legacy version of Guile, @code{guile@@2.0}:
8273 guix build --with-input=guile=guile@@2.0 guix
8276 This is a recursive, deep replacement. So in this example, both
8277 @code{guix} and its dependency @code{guile-json} (which also depends on
8278 @code{guile}) get rebuilt against @code{guile@@2.0}.
8280 This is implemented using the @code{package-input-rewriting} Scheme
8281 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8283 @item --with-graft=@var{package}=@var{replacement}
8284 This is similar to @code{--with-input} but with an important difference:
8285 instead of rebuilding the whole dependency chain, @var{replacement} is
8286 built and then @dfn{grafted} onto the binaries that were initially
8287 referring to @var{package}. @xref{Security Updates}, for more
8288 information on grafts.
8290 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8291 and all its dependencies, replacing references to the version of GnuTLS
8292 they currently refer to:
8295 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8298 This has the advantage of being much faster than rebuilding everything.
8299 But there is a caveat: it works if and only if @var{package} and
8300 @var{replacement} are strictly compatible---for example, if they provide
8301 a library, the application binary interface (ABI) of those libraries
8302 must be compatible. If @var{replacement} is somehow incompatible with
8303 @var{package}, then the resulting package may be unusable. Use with
8306 @item --with-git-url=@var{package}=@var{url}
8307 @cindex Git, using the latest commit
8308 @cindex latest commit, building
8309 Build @var{package} from the latest commit of the @code{master} branch of the
8310 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8313 For example, the following command builds the NumPy Python library against the
8314 latest commit of the master branch of Python itself:
8317 guix build python-numpy \
8318 --with-git-url=python=https://github.com/python/cpython
8321 This option can also be combined with @code{--with-branch} or
8322 @code{--with-commit} (see below).
8324 @cindex continuous integration
8325 Obviously, since it uses the latest commit of the given branch, the result of
8326 such a command varies over time. Nevertheless it is a convenient way to
8327 rebuild entire software stacks against the latest commit of one or more
8328 packages. This is particularly useful in the context of continuous
8331 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8332 consecutive accesses to the same repository. You may want to clean it up once
8333 in a while to save disk space.
8335 @item --with-branch=@var{package}=@var{branch}
8336 Build @var{package} from the latest commit of @var{branch}. If the
8337 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8338 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8339 repository URL is taken from that @code{source}. Otherwise you have to use
8340 @code{--with-git-url} to specify the URL of the Git repository.
8342 For instance, the following command builds @code{guile-sqlite3} from the
8343 latest commit of its @code{master} branch, and then builds @code{guix} (which
8344 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8345 specific @code{guile-sqlite3} build:
8348 guix build --with-branch=guile-sqlite3=master cuirass
8351 @item --with-commit=@var{package}=@var{commit}
8352 This is similar to @code{--with-branch}, except that it builds from
8353 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8354 Git commit SHA1 identifier or a tag.
8357 @node Additional Build Options
8358 @subsection Additional Build Options
8360 The command-line options presented below are specific to @command{guix
8367 Build quietly, without displaying the build log; this is equivalent to
8368 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8369 (or similar) and can always be retrieved using the @option{--log-file} option.
8371 @item --file=@var{file}
8372 @itemx -f @var{file}
8373 Build the package, derivation, or other file-like object that the code within
8374 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8376 As an example, @var{file} might contain a package definition like this
8377 (@pxref{Defining Packages}):
8380 @include package-hello.scm
8383 @item --expression=@var{expr}
8384 @itemx -e @var{expr}
8385 Build the package or derivation @var{expr} evaluates to.
8387 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8388 guile-1.8)}, which unambiguously designates this specific variant of
8389 version 1.8 of Guile.
8391 Alternatively, @var{expr} may be a G-expression, in which case it is used
8392 as a build program passed to @code{gexp->derivation}
8393 (@pxref{G-Expressions}).
8395 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8396 (@pxref{The Store Monad}). The procedure must return a derivation as a
8397 monadic value, which is then passed through @code{run-with-store}.
8401 Build the source derivations of the packages, rather than the packages
8404 For instance, @code{guix build -S gcc} returns something like
8405 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8408 The returned source tarball is the result of applying any patches and
8409 code snippets specified in the package @code{origin} (@pxref{Defining
8412 Note that @command{guix build -S} compiles the sources only of the
8413 specified packages. They do not include the sources of statically
8414 linked dependencies and by themselves are insufficient for reproducing
8418 Fetch and return the source of @var{package-or-derivation} and all their
8419 dependencies, recursively. This is a handy way to obtain a local copy
8420 of all the source code needed to build @var{packages}, allowing you to
8421 eventually build them even without network access. It is an extension
8422 of the @code{--source} option and can accept one of the following
8423 optional argument values:
8427 This value causes the @code{--sources} option to behave in the same way
8428 as the @code{--source} option.
8431 Build the source derivations of all packages, including any source that
8432 might be listed as @code{inputs}. This is the default value.
8435 $ guix build --sources tzdata
8436 The following derivations will be built:
8437 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8438 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8442 Build the source derivations of all packages, as well of all transitive
8443 inputs to the packages. This can be used e.g.@: to
8444 prefetch package source for later offline building.
8447 $ guix build --sources=transitive tzdata
8448 The following derivations will be built:
8449 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8450 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8451 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8452 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8453 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8454 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8460 @item --system=@var{system}
8461 @itemx -s @var{system}
8462 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8463 the system type of the build host. The @command{guix build} command allows
8464 you to repeat this option several times, in which case it builds for all the
8465 specified systems; other commands ignore extraneous @option{-s} options.
8468 The @code{--system} flag is for @emph{native} compilation and must not
8469 be confused with cross-compilation. See @code{--target} below for
8470 information on cross-compilation.
8473 An example use of this is on Linux-based systems, which can emulate
8474 different personalities. For instance, passing
8475 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8476 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8477 to build packages in a complete 32-bit environment.
8480 Building for an @code{armhf-linux} system is unconditionally enabled on
8481 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8482 allow for this functionality, notably the ThunderX.
8485 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8486 is enabled (@pxref{Virtualization Services,
8487 @code{qemu-binfmt-service-type}}), you can build for any system for
8488 which a QEMU @code{binfmt_misc} handler is installed.
8490 Builds for a system other than that of the machine you are using can
8491 also be offloaded to a remote machine of the right architecture.
8492 @xref{Daemon Offload Setup}, for more information on offloading.
8494 @item --target=@var{triplet}
8495 @cindex cross-compilation
8496 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8497 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8498 configuration triplets,, autoconf, Autoconf}).
8500 @anchor{build-check}
8502 @cindex determinism, checking
8503 @cindex reproducibility, checking
8504 Rebuild @var{package-or-derivation}, which are already available in the
8505 store, and raise an error if the build results are not bit-for-bit
8508 This mechanism allows you to check whether previously installed
8509 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8510 of a package is deterministic. @xref{Invoking guix challenge}, for more
8511 background information and tools.
8513 When used in conjunction with @option{--keep-failed}, the differing
8514 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8515 This makes it easy to look for differences between the two results.
8518 @cindex repairing store items
8519 @cindex corruption, recovering from
8520 Attempt to repair the specified store items, if they are corrupt, by
8521 re-downloading or rebuilding them.
8523 This operation is not atomic and thus restricted to @code{root}.
8527 Return the derivation paths, not the output paths, of the given
8530 @item --root=@var{file}
8531 @itemx -r @var{file}
8532 @cindex GC roots, adding
8533 @cindex garbage collector roots, adding
8534 Make @var{file} a symlink to the result, and register it as a garbage
8537 Consequently, the results of this @command{guix build} invocation are
8538 protected from garbage collection until @var{file} is removed. When
8539 that option is omitted, build results are eligible for garbage
8540 collection as soon as the build completes. @xref{Invoking guix gc}, for
8544 @cindex build logs, access
8545 Return the build log file names or URLs for the given
8546 @var{package-or-derivation}, or raise an error if build logs are
8549 This works regardless of how packages or derivations are specified. For
8550 instance, the following invocations are equivalent:
8553 guix build --log-file `guix build -d guile`
8554 guix build --log-file `guix build guile`
8555 guix build --log-file guile
8556 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8559 If a log is unavailable locally, and unless @code{--no-substitutes} is
8560 passed, the command looks for a corresponding log on one of the
8561 substitute servers (as specified with @code{--substitute-urls}.)
8563 So for instance, imagine you want to see the build log of GDB on MIPS,
8564 but you are actually on an @code{x86_64} machine:
8567 $ guix build --log-file gdb -s mips64el-linux
8568 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8571 You can freely access a huge library of build logs!
8574 @node Debugging Build Failures
8575 @subsection Debugging Build Failures
8577 @cindex build failures, debugging
8578 When defining a new package (@pxref{Defining Packages}), you will
8579 probably find yourself spending some time debugging and tweaking the
8580 build until it succeeds. To do that, you need to operate the build
8581 commands yourself in an environment as close as possible to the one the
8584 To that end, the first thing to do is to use the @option{--keep-failed}
8585 or @option{-K} option of @command{guix build}, which will keep the
8586 failed build tree in @file{/tmp} or whatever directory you specified as
8587 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8589 From there on, you can @command{cd} to the failed build tree and source
8590 the @file{environment-variables} file, which contains all the
8591 environment variable definitions that were in place when the build
8592 failed. So let's say you're debugging a build failure in package
8593 @code{foo}; a typical session would look like this:
8597 @dots{} @i{build fails}
8598 $ cd /tmp/guix-build-foo.drv-0
8599 $ source ./environment-variables
8603 Now, you can invoke commands as if you were the daemon (almost) and
8604 troubleshoot your build process.
8606 Sometimes it happens that, for example, a package's tests pass when you
8607 run them manually but they fail when the daemon runs them. This can
8608 happen because the daemon runs builds in containers where, unlike in our
8609 environment above, network access is missing, @file{/bin/sh} does not
8610 exist, etc. (@pxref{Build Environment Setup}).
8612 In such cases, you may need to run inspect the build process from within
8613 a container similar to the one the build daemon creates:
8618 $ cd /tmp/guix-build-foo.drv-0
8619 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8620 [env]# source ./environment-variables
8624 Here, @command{guix environment -C} creates a container and spawns a new
8625 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8626 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8627 the container, which would may find handy while debugging. The
8628 @option{--no-grafts} option makes sure we get the exact same
8629 environment, with ungrafted packages (@pxref{Security Updates}, for more
8632 To get closer to a container like that used by the build daemon, we can
8633 remove @file{/bin/sh}:
8639 (Don't worry, this is harmless: this is all happening in the throw-away
8640 container created by @command{guix environment}.)
8642 The @command{strace} command is probably not in the search path, but we
8646 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8649 In this way, not only you will have reproduced the environment variables
8650 the daemon uses, you will also be running the build process in a container
8651 similar to the one the daemon uses.
8654 @node Invoking guix edit
8655 @section Invoking @command{guix edit}
8657 @cindex @command{guix edit}
8658 @cindex package definition, editing
8659 So many packages, so many source files! The @command{guix edit} command
8660 facilitates the life of users and packagers by pointing their editor at
8661 the source file containing the definition of the specified packages.
8665 guix edit gcc@@4.9 vim
8669 launches the program specified in the @code{VISUAL} or in the
8670 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8673 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8674 have created your own packages on @code{GUIX_PACKAGE_PATH}
8675 (@pxref{Package Modules}), you will be able to edit the package
8676 recipes. In other cases, you will be able to examine the read-only recipes
8677 for packages currently in the store.
8680 @node Invoking guix download
8681 @section Invoking @command{guix download}
8683 @cindex @command{guix download}
8684 @cindex downloading package sources
8685 When writing a package definition, developers typically need to download
8686 a source tarball, compute its SHA256 hash, and write that
8687 hash in the package definition (@pxref{Defining Packages}). The
8688 @command{guix download} tool helps with this task: it downloads a file
8689 from the given URI, adds it to the store, and prints both its file name
8690 in the store and its SHA256 hash.
8692 The fact that the downloaded file is added to the store saves bandwidth:
8693 when the developer eventually tries to build the newly defined package
8694 with @command{guix build}, the source tarball will not have to be
8695 downloaded again because it is already in the store. It is also a
8696 convenient way to temporarily stash files, which may be deleted
8697 eventually (@pxref{Invoking guix gc}).
8699 The @command{guix download} command supports the same URIs as used in
8700 package definitions. In particular, it supports @code{mirror://} URIs.
8701 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8702 Guile bindings for GnuTLS are available in the user's environment; when
8703 they are not available, an error is raised. @xref{Guile Preparations,
8704 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8705 GnuTLS-Guile}, for more information.
8707 @command{guix download} verifies HTTPS server certificates by loading
8708 the certificates of X.509 authorities from the directory pointed to by
8709 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8710 Certificates}), unless @option{--no-check-certificate} is used.
8712 The following options are available:
8715 @item --format=@var{fmt}
8717 Write the hash in the format specified by @var{fmt}. For more
8718 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8720 @item --no-check-certificate
8721 Do not validate the X.509 certificates of HTTPS servers.
8723 When using this option, you have @emph{absolutely no guarantee} that you
8724 are communicating with the authentic server responsible for the given
8725 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8727 @item --output=@var{file}
8728 @itemx -o @var{file}
8729 Save the downloaded file to @var{file} instead of adding it to the
8733 @node Invoking guix hash
8734 @section Invoking @command{guix hash}
8736 @cindex @command{guix hash}
8737 The @command{guix hash} command computes the SHA256 hash of a file.
8738 It is primarily a convenience tool for anyone contributing to the
8739 distribution: it computes the cryptographic hash of a file, which can be
8740 used in the definition of a package (@pxref{Defining Packages}).
8742 The general syntax is:
8745 guix hash @var{option} @var{file}
8748 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8749 hash of data read from standard input. @command{guix hash} has the
8754 @item --format=@var{fmt}
8756 Write the hash in the format specified by @var{fmt}.
8758 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8759 (@code{hex} and @code{hexadecimal} can be used as well).
8761 If the @option{--format} option is not specified, @command{guix hash}
8762 will output the hash in @code{nix-base32}. This representation is used
8763 in the definitions of packages.
8767 Compute the hash on @var{file} recursively.
8769 In this case, the hash is computed on an archive containing @var{file},
8770 including its children if it is a directory. Some of the metadata of
8771 @var{file} is part of the archive; for instance, when @var{file} is a
8772 regular file, the hash is different depending on whether @var{file} is
8773 executable or not. Metadata such as time stamps has no impact on the
8774 hash (@pxref{Invoking guix archive}).
8775 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8780 When combined with @option{--recursive}, exclude version control system
8781 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8784 As an example, here is how you would compute the hash of a Git checkout,
8785 which is useful when using the @code{git-fetch} method (@pxref{origin
8789 $ git clone http://example.org/foo.git
8795 @node Invoking guix import
8796 @section Invoking @command{guix import}
8798 @cindex importing packages
8799 @cindex package import
8800 @cindex package conversion
8801 @cindex Invoking @command{guix import}
8802 The @command{guix import} command is useful for people who would like to
8803 add a package to the distribution with as little work as
8804 possible---a legitimate demand. The command knows of a few
8805 repositories from which it can ``import'' package metadata. The result
8806 is a package definition, or a template thereof, in the format we know
8807 (@pxref{Defining Packages}).
8809 The general syntax is:
8812 guix import @var{importer} @var{options}@dots{}
8815 @var{importer} specifies the source from which to import package
8816 metadata, and @var{options} specifies a package identifier and other
8817 options specific to @var{importer}.
8819 Some of the importers rely on the ability to run the @command{gpgv} command.
8820 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
8823 Currently, the available ``importers'' are:
8827 Import metadata for the given GNU package. This provides a template
8828 for the latest version of that GNU package, including the hash of its
8829 source tarball, and its canonical synopsis and description.
8831 Additional information such as the package dependencies and its
8832 license needs to be figured out manually.
8834 For example, the following command returns a package definition for
8838 guix import gnu hello
8841 Specific command-line options are:
8844 @item --key-download=@var{policy}
8845 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8846 keys when verifying the package signature. @xref{Invoking guix
8847 refresh, @code{--key-download}}.
8852 Import metadata from the @uref{https://pypi.python.org/, Python Package
8853 Index}. Information is taken from the JSON-formatted description
8854 available at @code{pypi.python.org} and usually includes all the relevant
8855 information, including package dependencies. For maximum efficiency, it
8856 is recommended to install the @command{unzip} utility, so that the
8857 importer can unzip Python wheels and gather data from them.
8859 The command below imports metadata for the @code{itsdangerous} Python
8863 guix import pypi itsdangerous
8869 Traverse the dependency graph of the given upstream package recursively
8870 and generate package expressions for all those packages that are not yet
8876 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8877 is taken from the JSON-formatted description available at
8878 @code{rubygems.org} and includes most relevant information, including
8879 runtime dependencies. There are some caveats, however. The metadata
8880 doesn't distinguish between synopses and descriptions, so the same string
8881 is used for both fields. Additionally, the details of non-Ruby
8882 dependencies required to build native extensions is unavailable and left
8883 as an exercise to the packager.
8885 The command below imports metadata for the @code{rails} Ruby package:
8888 guix import gem rails
8894 Traverse the dependency graph of the given upstream package recursively
8895 and generate package expressions for all those packages that are not yet
8901 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8902 Information is taken from the JSON-formatted metadata provided through
8903 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8904 relevant information, such as module dependencies. License information
8905 should be checked closely. If Perl is available in the store, then the
8906 @code{corelist} utility will be used to filter core modules out of the
8907 list of dependencies.
8909 The command command below imports metadata for the @code{Acme::Boolean}
8913 guix import cpan Acme::Boolean
8918 @cindex Bioconductor
8919 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8920 central repository for the @uref{https://r-project.org, GNU@tie{}R
8921 statistical and graphical environment}.
8923 Information is extracted from the @code{DESCRIPTION} file of the package.
8925 The command command below imports metadata for the @code{Cairo}
8929 guix import cran Cairo
8932 When @code{--recursive} is added, the importer will traverse the
8933 dependency graph of the given upstream package recursively and generate
8934 package expressions for all those packages that are not yet in Guix.
8936 When @code{--archive=bioconductor} is added, metadata is imported from
8937 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8938 packages for for the analysis and comprehension of high-throughput
8939 genomic data in bioinformatics.
8941 Information is extracted from the @code{DESCRIPTION} file contained in the
8944 The command below imports metadata for the @code{GenomicRanges}
8948 guix import cran --archive=bioconductor GenomicRanges
8951 Finally, you can also import R packages that have not yet been published on
8952 CRAN or Bioconductor as long as they are in a git repository. Use
8953 @code{--archive=git} followed by the URL of the git repository:
8956 guix import cran --archive=git https://github.com/immunogenomics/harmony
8962 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8963 comprehensive TeX archive network for TeX packages that are part of the
8964 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8966 Information about the package is obtained through the XML API provided
8967 by CTAN, while the source code is downloaded from the SVN repository of
8968 the Tex Live project. This is done because the CTAN does not keep
8971 The command command below imports metadata for the @code{fontspec}
8975 guix import texlive fontspec
8978 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8979 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8980 tree in the TeX Live SVN repository, but from the specified sibling
8981 directory under the same root.
8983 The command below imports metadata for the @code{ifxetex} package from
8984 CTAN while fetching the sources from the directory
8985 @file{texmf/source/generic}:
8988 guix import texlive --archive=generic ifxetex
8992 @cindex JSON, import
8993 Import package metadata from a local JSON file. Consider the following
8994 example package definition in JSON format:
9000 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9001 "build-system": "gnu",
9002 "home-page": "https://www.gnu.org/software/hello/",
9003 "synopsis": "Hello, GNU world: An example GNU package",
9004 "description": "GNU Hello prints a greeting.",
9005 "license": "GPL-3.0+",
9006 "native-inputs": ["gettext"]
9010 The field names are the same as for the @code{<package>} record
9011 (@xref{Defining Packages}). References to other packages are provided
9012 as JSON lists of quoted package specification strings such as
9013 @code{guile} or @code{guile@@2.0}.
9015 The importer also supports a more explicit source definition using the
9016 common fields for @code{<origin>} records:
9022 "method": "url-fetch",
9023 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9025 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9032 The command below reads metadata from the JSON file @code{hello.json}
9033 and outputs a package expression:
9036 guix import json hello.json
9040 Import metadata from a local copy of the source of the
9041 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9042 relies on the @command{nix-instantiate} command of
9043 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9044 typically written in a mixture of Nix-language and Bash code. This
9045 command only imports the high-level package structure that is written in
9046 the Nix language. It normally includes all the basic fields of a
9049 When importing a GNU package, the synopsis and descriptions are replaced
9050 by their canonical upstream variant.
9052 Usually, you will first need to do:
9055 export NIX_REMOTE=daemon
9059 so that @command{nix-instantiate} does not try to open the Nix database.
9061 As an example, the command below imports the package definition of
9062 LibreOffice (more precisely, it imports the definition of the package
9063 bound to the @code{libreoffice} top-level attribute):
9066 guix import nix ~/path/to/nixpkgs libreoffice
9071 Import metadata from the Haskell community's central package archive
9072 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9073 Cabal files and includes all the relevant information, including package
9076 Specific command-line options are:
9081 Read a Cabal file from standard input.
9082 @item --no-test-dependencies
9084 Do not include dependencies required only by the test suites.
9085 @item --cabal-environment=@var{alist}
9086 @itemx -e @var{alist}
9087 @var{alist} is a Scheme alist defining the environment in which the
9088 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9089 @code{arch}, @code{impl} and a string representing the name of a flag.
9090 The value associated with a flag has to be either the symbol
9091 @code{true} or @code{false}. The value associated with other keys
9092 has to conform to the Cabal file format definition. The default value
9093 associated with the keys @code{os}, @code{arch} and @code{impl} is
9094 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9097 Traverse the dependency graph of the given upstream package recursively
9098 and generate package expressions for all those packages that are not yet
9102 The command below imports metadata for the latest version of the
9103 @code{HTTP} Haskell package without including test dependencies and
9104 specifying the value of the flag @samp{network-uri} as @code{false}:
9107 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9110 A specific package version may optionally be specified by following the
9111 package name by an at-sign and a version number as in the following example:
9114 guix import hackage mtl@@2.1.3.1
9119 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9120 It takes a package name, looks up the package version included in a
9121 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9122 release and uses the @code{hackage} importer to retrieve its metadata.
9123 Note that it is up to you to select an LTS release compatible with the
9124 GHC compiler used by Guix.
9126 Specific command-line options are:
9129 @item --no-test-dependencies
9131 Do not include dependencies required only by the test suites.
9132 @item --lts-version=@var{version}
9133 @itemx -l @var{version}
9134 @var{version} is the desired LTS release version. If omitted the latest
9138 Traverse the dependency graph of the given upstream package recursively
9139 and generate package expressions for all those packages that are not yet
9143 The command below imports metadata for the @code{HTTP} Haskell package
9144 included in the LTS Stackage release version 7.18:
9147 guix import stackage --lts-version=7.18 HTTP
9152 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9153 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9155 Specific command-line options are:
9158 @item --archive=@var{repo}
9159 @itemx -a @var{repo}
9160 @var{repo} identifies the archive repository from which to retrieve the
9161 information. Currently the supported repositories and their identifiers
9165 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9166 identifier. This is the default.
9168 Packages from @code{elpa.gnu.org} are signed with one of the keys
9169 contained in the GnuPG keyring at
9170 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9171 @code{emacs} package (@pxref{Package Installation, ELPA package
9172 signatures,, emacs, The GNU Emacs Manual}).
9175 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9176 @code{melpa-stable} identifier.
9179 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9185 Traverse the dependency graph of the given upstream package recursively
9186 and generate package expressions for all those packages that are not yet
9192 Import metadata from the crates.io Rust package repository
9193 @uref{https://crates.io, crates.io}, as in this example:
9196 guix import crate blake2-rfc
9199 The crate importer also allows you to specify a version string:
9202 guix import crate constant-time-eq@@0.1.0
9205 Additional options include:
9210 Traverse the dependency graph of the given upstream package recursively
9211 and generate package expressions for all those packages that are not yet
9218 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9219 repository used by the OCaml community.
9222 The structure of the @command{guix import} code is modular. It would be
9223 useful to have more importers for other package formats, and your help
9224 is welcome here (@pxref{Contributing}).
9226 @node Invoking guix refresh
9227 @section Invoking @command{guix refresh}
9229 @cindex @command {guix refresh}
9230 The primary audience of the @command{guix refresh} command is developers
9231 of the GNU software distribution. By default, it reports any packages
9232 provided by the distribution that are outdated compared to the latest
9233 upstream version, like this:
9237 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9238 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9241 Alternately, one can specify packages to consider, in which case a
9242 warning is emitted for packages that lack an updater:
9245 $ guix refresh coreutils guile guile-ssh
9246 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9247 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9250 @command{guix refresh} browses the upstream repository of each package and determines
9251 the highest version number of the releases therein. The command
9252 knows how to update specific types of packages: GNU packages, ELPA
9253 packages, etc.---see the documentation for @option{--type} below. There
9254 are many packages, though, for which it lacks a method to determine
9255 whether a new upstream release is available. However, the mechanism is
9256 extensible, so feel free to get in touch with us to add a new method!
9261 Consider the packages specified, and all the packages upon which they depend.
9264 $ guix refresh --recursive coreutils
9265 gnu/packages/acl.scm:35:2: warning: no updater for acl
9266 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9267 gnu/packages/xml.scm:68:2: warning: no updater for expat
9268 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9274 Sometimes the upstream name differs from the package name used in Guix,
9275 and @command{guix refresh} needs a little help. Most updaters honor the
9276 @code{upstream-name} property in package definitions, which can be used
9280 (define-public network-manager
9282 (name "network-manager")
9284 (properties '((upstream-name . "NetworkManager")))))
9287 When passed @code{--update}, it modifies distribution source files to
9288 update the version numbers and source tarball hashes of those package
9289 recipes (@pxref{Defining Packages}). This is achieved by downloading
9290 each package's latest source tarball and its associated OpenPGP
9291 signature, authenticating the downloaded tarball against its signature
9292 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9293 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9296 key used to sign the tarball is missing from the user's keyring, an
9297 attempt is made to automatically retrieve it from a public key server;
9298 when this is successful, the key is added to the user's keyring; otherwise,
9299 @command{guix refresh} reports an error.
9301 The following options are supported:
9305 @item --expression=@var{expr}
9306 @itemx -e @var{expr}
9307 Consider the package @var{expr} evaluates to.
9309 This is useful to precisely refer to a package, as in this example:
9312 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9315 This command lists the dependents of the ``final'' libc (essentially all
9320 Update distribution source files (package recipes) in place. This is
9321 usually run from a checkout of the Guix source tree (@pxref{Running
9322 Guix Before It Is Installed}):
9325 $ ./pre-inst-env guix refresh -s non-core -u
9328 @xref{Defining Packages}, for more information on package definitions.
9330 @item --select=[@var{subset}]
9331 @itemx -s @var{subset}
9332 Select all the packages in @var{subset}, one of @code{core} or
9335 The @code{core} subset refers to all the packages at the core of the
9336 distribution---i.e., packages that are used to build ``everything
9337 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9338 changing one of these packages in the distribution entails a rebuild of
9339 all the others. Thus, such updates are an inconvenience to users in
9340 terms of build time or bandwidth used to achieve the upgrade.
9342 The @code{non-core} subset refers to the remaining packages. It is
9343 typically useful in cases where an update of the core packages would be
9346 @item --manifest=@var{file}
9347 @itemx -m @var{file}
9348 Select all the packages from the manifest in @var{file}. This is useful to
9349 check if any packages of the user manifest can be updated.
9351 @item --type=@var{updater}
9352 @itemx -t @var{updater}
9353 Select only packages handled by @var{updater} (may be a comma-separated
9354 list of updaters). Currently, @var{updater} may be one of:
9358 the updater for GNU packages;
9360 the updater for GNOME packages;
9362 the updater for KDE packages;
9364 the updater for X.org packages;
9366 the updater for packages hosted on kernel.org;
9368 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9370 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9372 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9374 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9376 the updater for @uref{https://pypi.python.org, PyPI} packages.
9378 the updater for @uref{https://rubygems.org, RubyGems} packages.
9380 the updater for @uref{https://github.com, GitHub} packages.
9382 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9384 the updater for @uref{https://www.stackage.org, Stackage} packages.
9386 the updater for @uref{https://crates.io, Crates} packages.
9388 the updater for @uref{https://launchpad.net, Launchpad} packages.
9391 For instance, the following command only checks for updates of Emacs
9392 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9395 $ guix refresh --type=elpa,cran
9396 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9397 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9402 In addition, @command{guix refresh} can be passed one or more package
9403 names, as in this example:
9406 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9410 The command above specifically updates the @code{emacs} and
9411 @code{idutils} packages. The @code{--select} option would have no
9412 effect in this case.
9414 When considering whether to upgrade a package, it is sometimes
9415 convenient to know which packages would be affected by the upgrade and
9416 should be checked for compatibility. For this the following option may
9417 be used when passing @command{guix refresh} one or more package names:
9421 @item --list-updaters
9423 List available updaters and exit (see @option{--type} above.)
9425 For each updater, display the fraction of packages it covers; at the
9426 end, display the fraction of packages covered by all these updaters.
9428 @item --list-dependent
9430 List top-level dependent packages that would need to be rebuilt as a
9431 result of upgrading one or more packages.
9433 @xref{Invoking guix graph, the @code{reverse-package} type of
9434 @command{guix graph}}, for information on how to visualize the list of
9435 dependents of a package.
9439 Be aware that the @code{--list-dependent} option only
9440 @emph{approximates} the rebuilds that would be required as a result of
9441 an upgrade. More rebuilds might be required under some circumstances.
9444 $ guix refresh --list-dependent flex
9445 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9446 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9449 The command above lists a set of packages that could be built to check
9450 for compatibility with an upgraded @code{flex} package.
9454 @item --list-transitive
9455 List all the packages which one or more packages depend upon.
9458 $ guix refresh --list-transitive flex
9459 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9460 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{}
9465 The command above lists a set of packages which, when changed, would cause
9466 @code{flex} to be rebuilt.
9468 The following options can be used to customize GnuPG operation:
9472 @item --gpg=@var{command}
9473 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9474 for in @code{$PATH}.
9476 @item --keyring=@var{file}
9477 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9478 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9479 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9480 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9481 information on a tool to manipulate keybox files).
9483 When this option is omitted, @command{guix refresh} uses
9484 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9485 signing keys. OpenPGP signatures are checked against keys from this keyring;
9486 missing keys are downloaded to this keyring as well (see
9487 @option{--key-download} below.)
9489 You can export keys from your default GPG keyring into a keybox file using
9490 commands like this one:
9493 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9496 Likewise, you can fetch keys to a specific keybox file like this:
9499 gpg --no-default-keyring --keyring mykeyring.kbx \
9500 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9503 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9504 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9506 @item --key-download=@var{policy}
9507 Handle missing OpenPGP keys according to @var{policy}, which may be one
9512 Always download missing OpenPGP keys from the key server, and add them
9513 to the user's GnuPG keyring.
9516 Never try to download missing OpenPGP keys. Instead just bail out.
9519 When a package signed with an unknown OpenPGP key is encountered, ask
9520 the user whether to download it or not. This is the default behavior.
9523 @item --key-server=@var{host}
9524 Use @var{host} as the OpenPGP key server when importing a public key.
9528 The @code{github} updater uses the
9529 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9530 releases. When used repeatedly e.g.@: when refreshing all packages,
9531 GitHub will eventually refuse to answer any further API requests. By
9532 default 60 API requests per hour are allowed, and a full refresh on all
9533 GitHub packages in Guix requires more than this. Authentication with
9534 GitHub through the use of an API token alleviates these limits. To use
9535 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9536 token procured from @uref{https://github.com/settings/tokens} or
9540 @node Invoking guix lint
9541 @section Invoking @command{guix lint}
9543 @cindex @command{guix lint}
9544 @cindex package, checking for errors
9545 The @command{guix lint} command is meant to help package developers avoid
9546 common errors and use a consistent style. It runs a number of checks on
9547 a given set of packages in order to find common mistakes in their
9548 definitions. Available @dfn{checkers} include (see
9549 @code{--list-checkers} for a complete list):
9554 Validate certain typographical and stylistic rules about package
9555 descriptions and synopses.
9557 @item inputs-should-be-native
9558 Identify inputs that should most likely be native inputs.
9564 @itemx source-file-name
9565 Probe @code{home-page} and @code{source} URLs and report those that are
9566 invalid. Suggest a @code{mirror://} URL when applicable. If the
9567 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9568 URL. Check that the source file name is meaningful, e.g.@: is not just a
9569 version number or ``git-checkout'', without a declared @code{file-name}
9570 (@pxref{origin Reference}).
9572 @item source-unstable-tarball
9573 Parse the @code{source} URL to determine if a tarball from GitHub is
9574 autogenerated or if it is a release tarball. Unfortunately GitHub's
9575 autogenerated tarballs are sometimes regenerated.
9578 @cindex Software Heritage, source code archive
9579 @cindex archival of source code, Software Heritage
9580 Checks whether the package's source code is archived at
9581 @uref{https://www.softwareheritage.org, Software Heritage}.
9583 When the source code that is not archived comes from a version-control system
9584 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9585 ``save'' request so that it eventually archives it. This ensures that the
9586 source will remain available in the long term, and that Guix can fall back to
9587 Software Heritage should the source code disappear from its original host.
9588 The status of recent ``save'' requests can be
9589 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9591 When source code is a tarball obtained with @code{url-fetch}, simply print a
9592 message when it is not archived. As of this writing, Software Heritage does
9593 not allow requests to save arbitrary tarballs; we are working on ways to
9594 ensure that non-VCS source code is also archived.
9597 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9598 request rate per IP address}. When the limit is reached, @command{guix lint}
9599 prints a message and the @code{archival} checker stops doing anything until
9600 that limit has been reset.
9603 @cindex security vulnerabilities
9604 @cindex CVE, Common Vulnerabilities and Exposures
9605 Report known vulnerabilities found in the Common Vulnerabilities and
9606 Exposures (CVE) databases of the current and past year
9607 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9610 To view information about a particular vulnerability, visit pages such as:
9614 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9616 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9620 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9621 @code{CVE-2015-7554}.
9623 Package developers can specify in package recipes the
9624 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9625 name and version of the package when they differ from the name or version
9626 that Guix uses, as in this example:
9632 ;; CPE calls this package "grub2".
9633 (properties '((cpe-name . "grub2")
9634 (cpe-version . "2.3"))))
9637 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9638 Some entries in the CVE database do not specify which version of a
9639 package they apply to, and would thus ``stick around'' forever. Package
9640 developers who found CVE alerts and verified they can be ignored can
9641 declare them as in this example:
9647 ;; These CVEs no longer apply and can be safely ignored.
9648 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9651 "CVE-2011-5244")))))
9655 Warn about obvious source code formatting issues: trailing white space,
9656 use of tabulations, etc.
9659 The general syntax is:
9662 guix lint @var{options} @var{package}@dots{}
9665 If no package is given on the command line, then all packages are checked.
9666 The @var{options} may be zero or more of the following:
9669 @item --list-checkers
9671 List and describe all the available checkers that will be run on packages
9676 Only enable the checkers specified in a comma-separated list using the
9677 names returned by @code{--list-checkers}.
9681 @node Invoking guix size
9682 @section Invoking @command{guix size}
9685 @cindex package size
9687 @cindex @command{guix size}
9688 The @command{guix size} command helps package developers profile the
9689 disk usage of packages. It is easy to overlook the impact of an
9690 additional dependency added to a package, or the impact of using a
9691 single output for a package that could easily be split (@pxref{Packages
9692 with Multiple Outputs}). Such are the typical issues that
9693 @command{guix size} can highlight.
9695 The command can be passed one or more package specifications
9696 such as @code{gcc@@4.8}
9697 or @code{guile:debug}, or a file name in the store. Consider this
9701 $ guix size coreutils
9702 store item total self
9703 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9704 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9705 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9706 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9707 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9708 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9709 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9710 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9715 The store items listed here constitute the @dfn{transitive closure} of
9716 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9717 would be returned by:
9720 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9723 Here the output shows three columns next to store items. The first column,
9724 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9725 the store item---that is, its own size plus the size of all its
9726 dependencies. The next column, labeled ``self'', shows the size of the
9727 item itself. The last column shows the ratio of the size of the item
9728 itself to the space occupied by all the items listed here.
9730 In this example, we see that the closure of Coreutils weighs in at
9731 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9732 libraries. (That libc and GCC's libraries represent a large fraction of
9733 the closure is not a problem @i{per se} because they are always available
9734 on the system anyway.)
9736 When the package(s) passed to @command{guix size} are available in the
9737 store@footnote{More precisely, @command{guix size} looks for the
9738 @emph{ungrafted} variant of the given package(s), as returned by
9739 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9740 for information on grafts.}, @command{guix size} queries the daemon to determine its
9741 dependencies, and measures its size in the store, similar to @command{du
9742 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9745 When the given packages are @emph{not} in the store, @command{guix size}
9746 reports information based on the available substitutes
9747 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9748 store items that are not even on disk, only available remotely.
9750 You can also specify several package names:
9753 $ guix size coreutils grep sed bash
9754 store item total self
9755 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9756 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9757 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9758 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9764 In this example we see that the combination of the four packages takes
9765 102.3@tie{}MiB in total, which is much less than the sum of each closure
9766 since they have a lot of dependencies in common.
9768 The available options are:
9772 @item --substitute-urls=@var{urls}
9773 Use substitute information from @var{urls}.
9774 @xref{client-substitute-urls, the same option for @code{guix build}}.
9776 @item --sort=@var{key}
9777 Sort lines according to @var{key}, one of the following options:
9781 the size of each item (the default);
9783 the total size of the item's closure.
9786 @item --map-file=@var{file}
9787 Write a graphical map of disk usage in PNG format to @var{file}.
9789 For the example above, the map looks like this:
9791 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9792 produced by @command{guix size}}
9794 This option requires that
9795 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9796 installed and visible in Guile's module search path. When that is not
9797 the case, @command{guix size} fails as it tries to load it.
9799 @item --system=@var{system}
9800 @itemx -s @var{system}
9801 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9805 @node Invoking guix graph
9806 @section Invoking @command{guix graph}
9809 @cindex @command{guix graph}
9810 @cindex package dependencies
9811 Packages and their dependencies form a @dfn{graph}, specifically a
9812 directed acyclic graph (DAG). It can quickly become difficult to have a
9813 mental model of the package DAG, so the @command{guix graph} command
9814 provides a visual representation of the DAG. By default,
9815 @command{guix graph} emits a DAG representation in the input format of
9816 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9817 directly to the @command{dot} command of Graphviz. It can also emit an
9818 HTML page with embedded JavaScript code to display a ``chord diagram''
9819 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9820 emit Cypher queries to construct a graph in a graph database supporting
9821 the @uref{https://www.opencypher.org/, openCypher} query language.
9822 The general syntax is:
9825 guix graph @var{options} @var{package}@dots{}
9828 For example, the following command generates a PDF file representing the
9829 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9833 guix graph coreutils | dot -Tpdf > dag.pdf
9836 The output looks like this:
9838 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9840 Nice little graph, no?
9842 But there is more than one graph! The one above is concise: it is the
9843 graph of package objects, omitting implicit inputs such as GCC, libc,
9844 grep, etc. It is often useful to have such a concise graph, but
9845 sometimes one may want to see more details. @command{guix graph} supports
9846 several types of graphs, allowing you to choose the level of detail:
9850 This is the default type used in the example above. It shows the DAG of
9851 package objects, excluding implicit dependencies. It is concise, but
9852 filters out many details.
9854 @item reverse-package
9855 This shows the @emph{reverse} DAG of packages. For example:
9858 guix graph --type=reverse-package ocaml
9861 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9862 you are also interested in cases where OCaml is an implicit dependency, see
9863 @code{reverse-bag} below.)
9865 Note that for core packages this can yield huge graphs. If all you want
9866 is to know the number of packages that depend on a given package, use
9867 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9868 @option{--list-dependent}}).
9871 This is the package DAG, @emph{including} implicit inputs.
9873 For instance, the following command:
9876 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9879 ...@: yields this bigger graph:
9881 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9883 At the bottom of the graph, we see all the implicit inputs of
9884 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9886 Now, note that the dependencies of these implicit inputs---that is, the
9887 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9888 here, for conciseness.
9891 Similar to @code{bag-emerged}, but this time including all the bootstrap
9894 @item bag-with-origins
9895 Similar to @code{bag}, but also showing origins and their dependencies.
9898 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9899 it also takes implicit dependencies into account. For example:
9902 guix graph -t reverse-bag dune
9906 ...@: yields the graph of all packages that depend on Dune, directly or
9907 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9908 @i{via} @code{dune-build-system}, this shows a large number of packages,
9909 whereas @code{reverse-package} would show very few if any.
9912 This is the most detailed representation: It shows the DAG of
9913 derivations (@pxref{Derivations}) and plain store items. Compared to
9914 the above representation, many additional nodes are visible, including
9915 build scripts, patches, Guile modules, etc.
9917 For this type of graph, it is also possible to pass a @file{.drv} file
9918 name instead of a package name, as in:
9921 guix graph -t derivation `guix system build -d my-config.scm`
9925 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9926 For example, the following command shows the graph for the package
9927 module that defines the @code{guile} package:
9930 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9934 All the types above correspond to @emph{build-time dependencies}. The
9935 following graph type represents the @emph{run-time dependencies}:
9939 This is the graph of @dfn{references} of a package output, as returned
9940 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9942 If the given package output is not available in the store, @command{guix
9943 graph} attempts to obtain dependency information from substitutes.
9945 Here you can also pass a store file name instead of a package name. For
9946 example, the command below produces the reference graph of your profile
9947 (which can be big!):
9950 guix graph -t references `readlink -f ~/.guix-profile`
9954 This is the graph of the @dfn{referrers} of a store item, as returned by
9955 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9957 This relies exclusively on local information from your store. For
9958 instance, let us suppose that the current Inkscape is available in 10
9959 profiles on your machine; @command{guix graph -t referrers inkscape}
9960 will show a graph rooted at Inkscape and with those 10 profiles linked
9963 It can help determine what is preventing a store item from being garbage
9968 The available options are the following:
9971 @item --type=@var{type}
9972 @itemx -t @var{type}
9973 Produce a graph output of @var{type}, where @var{type} must be one of
9974 the values listed above.
9977 List the supported graph types.
9979 @item --backend=@var{backend}
9980 @itemx -b @var{backend}
9981 Produce a graph using the selected @var{backend}.
9983 @item --list-backends
9984 List the supported graph backends.
9986 Currently, the available backends are Graphviz and d3.js.
9988 @item --expression=@var{expr}
9989 @itemx -e @var{expr}
9990 Consider the package @var{expr} evaluates to.
9992 This is useful to precisely refer to a package, as in this example:
9995 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9998 @item --system=@var{system}
9999 @itemx -s @var{system}
10000 Display the graph for @var{system}---e.g., @code{i686-linux}.
10002 The package dependency graph is largely architecture-independent, but there
10003 are some architecture-dependent bits that this option allows you to visualize.
10006 On top of that, @command{guix graph} supports all the usual package
10007 transformation options (@pxref{Package Transformation Options}). This
10008 makes it easy to view the effect of a graph-rewriting transformation
10009 such as @option{--with-input}. For example, the command below outputs
10010 the graph of @code{git} once @code{openssl} has been replaced by
10011 @code{libressl} everywhere in the graph:
10014 guix graph git --with-input=openssl=libressl
10017 So many possibilities, so much fun!
10019 @node Invoking guix publish
10020 @section Invoking @command{guix publish}
10022 @cindex @command{guix publish}
10023 The purpose of @command{guix publish} is to enable users to easily share
10024 their store with others, who can then use it as a substitute server
10025 (@pxref{Substitutes}).
10027 When @command{guix publish} runs, it spawns an HTTP server which allows
10028 anyone with network access to obtain substitutes from it. This means
10029 that any machine running Guix can also act as if it were a build farm,
10030 since the HTTP interface is compatible with Cuirass, the software behind
10031 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10033 For security, each substitute is signed, allowing recipients to check
10034 their authenticity and integrity (@pxref{Substitutes}). Because
10035 @command{guix publish} uses the signing key of the system, which is only
10036 readable by the system administrator, it must be started as root; the
10037 @code{--user} option makes it drop root privileges early on.
10039 The signing key pair must be generated before @command{guix publish} is
10040 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10043 The general syntax is:
10046 guix publish @var{options}@dots{}
10049 Running @command{guix publish} without any additional arguments will
10050 spawn an HTTP server on port 8080:
10056 Once a publishing server has been authorized (@pxref{Invoking guix
10057 archive}), the daemon may download substitutes from it:
10060 guix-daemon --substitute-urls=http://example.org:8080
10063 By default, @command{guix publish} compresses archives on the fly as it
10064 serves them. This ``on-the-fly'' mode is convenient in that it requires
10065 no setup and is immediately available. However, when serving lots of
10066 clients, we recommend using the @option{--cache} option, which enables
10067 caching of the archives before they are sent to clients---see below for
10068 details. The @command{guix weather} command provides a handy way to
10069 check what a server provides (@pxref{Invoking guix weather}).
10071 As a bonus, @command{guix publish} also serves as a content-addressed
10072 mirror for source files referenced in @code{origin} records
10073 (@pxref{origin Reference}). For instance, assuming @command{guix
10074 publish} is running on @code{example.org}, the following URL returns the
10075 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10076 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10079 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10082 Obviously, these URLs only work for files that are in the store; in
10083 other cases, they return 404 (``Not Found'').
10085 @cindex build logs, publication
10086 Build logs are available from @code{/log} URLs like:
10089 http://example.org/log/gwspk@dots{}-guile-2.2.3
10093 When @command{guix-daemon} is configured to save compressed build logs,
10094 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10095 URLs return the compressed log as-is, with an appropriate
10096 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10097 running @command{guix-daemon} with @code{--log-compression=gzip} since
10098 Web browsers can automatically decompress it, which is not the case with
10101 The following options are available:
10104 @item --port=@var{port}
10105 @itemx -p @var{port}
10106 Listen for HTTP requests on @var{port}.
10108 @item --listen=@var{host}
10109 Listen on the network interface for @var{host}. The default is to
10110 accept connections from any interface.
10112 @item --user=@var{user}
10113 @itemx -u @var{user}
10114 Change privileges to @var{user} as soon as possible---i.e., once the
10115 server socket is open and the signing key has been read.
10117 @item --compression[=@var{method}[:@var{level}]]
10118 @itemx -C [@var{method}[:@var{level}]]
10119 Compress data using the given @var{method} and @var{level}. @var{method} is
10120 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10123 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10124 to different compression levels: 1 is the fastest, and 9 is the best
10125 (CPU-intensive). The default is 3.
10127 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10128 increase in CPU usage; see
10129 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10132 Unless @option{--cache} is used, compression occurs on the fly and
10133 the compressed streams are not
10134 cached. Thus, to reduce load on the machine that runs @command{guix
10135 publish}, it may be a good idea to choose a low compression level, to
10136 run @command{guix publish} behind a caching proxy, or to use
10137 @option{--cache}. Using @option{--cache} has the advantage that it
10138 allows @command{guix publish} to add @code{Content-Length} HTTP header
10141 This option can be repeated, in which case every substitute gets compressed
10142 using all the selected methods, and all of them are advertised. This is
10143 useful when users may not support all the compression methods: they can select
10144 the one they support.
10146 @item --cache=@var{directory}
10147 @itemx -c @var{directory}
10148 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10149 and only serve archives that are in cache.
10151 When this option is omitted, archives and meta-data are created
10152 on-the-fly. This can reduce the available bandwidth, especially when
10153 compression is enabled, since this may become CPU-bound. Another
10154 drawback of the default mode is that the length of archives is not known
10155 in advance, so @command{guix publish} does not add a
10156 @code{Content-Length} HTTP header to its responses, which in turn
10157 prevents clients from knowing the amount of data being downloaded.
10159 Conversely, when @option{--cache} is used, the first request for a store
10160 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10161 background process to @dfn{bake} the archive---computing its
10162 @code{.narinfo} and compressing the archive, if needed. Once the
10163 archive is cached in @var{directory}, subsequent requests succeed and
10164 are served directly from the cache, which guarantees that clients get
10165 the best possible bandwidth.
10167 The ``baking'' process is performed by worker threads. By default, one
10168 thread per CPU core is created, but this can be customized. See
10169 @option{--workers} below.
10171 When @option{--ttl} is used, cached entries are automatically deleted
10172 when they have expired.
10174 @item --workers=@var{N}
10175 When @option{--cache} is used, request the allocation of @var{N} worker
10176 threads to ``bake'' archives.
10178 @item --ttl=@var{ttl}
10179 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10180 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10181 days, @code{1m} means 1 month, and so on.
10183 This allows the user's Guix to keep substitute information in cache for
10184 @var{ttl}. However, note that @code{guix publish} does not itself
10185 guarantee that the store items it provides will indeed remain available
10186 for as long as @var{ttl}.
10188 Additionally, when @option{--cache} is used, cached entries that have
10189 not been accessed for @var{ttl} and that no longer have a corresponding
10190 item in the store, may be deleted.
10192 @item --nar-path=@var{path}
10193 Use @var{path} as the prefix for the URLs of ``nar'' files
10194 (@pxref{Invoking guix archive, normalized archives}).
10196 By default, nars are served at a URL such as
10197 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10198 change the @code{/nar} part to @var{path}.
10200 @item --public-key=@var{file}
10201 @itemx --private-key=@var{file}
10202 Use the specific @var{file}s as the public/private key pair used to sign
10203 the store items being published.
10205 The files must correspond to the same key pair (the private key is used
10206 for signing and the public key is merely advertised in the signature
10207 metadata). They must contain keys in the canonical s-expression format
10208 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10209 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10210 @file{/etc/guix/signing-key.sec} are used.
10212 @item --repl[=@var{port}]
10213 @itemx -r [@var{port}]
10214 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10215 Reference Manual}) on @var{port} (37146 by default). This is used
10216 primarily for debugging a running @command{guix publish} server.
10219 Enabling @command{guix publish} on Guix System is a one-liner: just
10220 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10221 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10222 @code{guix-publish-service-type}}).
10224 If you are instead running Guix on a ``foreign distro'', follow these
10229 If your host distro uses the systemd init system:
10232 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10233 /etc/systemd/system/
10234 # systemctl start guix-publish && systemctl enable guix-publish
10238 If your host distro uses the Upstart init system:
10241 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10242 # start guix-publish
10246 Otherwise, proceed similarly with your distro's init system.
10249 @node Invoking guix challenge
10250 @section Invoking @command{guix challenge}
10252 @cindex reproducible builds
10253 @cindex verifiable builds
10254 @cindex @command{guix challenge}
10256 Do the binaries provided by this server really correspond to the source
10257 code it claims to build? Is a package build process deterministic?
10258 These are the questions the @command{guix challenge} command attempts to
10261 The former is obviously an important question: Before using a substitute
10262 server (@pxref{Substitutes}), one had better @emph{verify} that it
10263 provides the right binaries, and thus @emph{challenge} it. The latter
10264 is what enables the former: If package builds are deterministic, then
10265 independent builds of the package should yield the exact same result,
10266 bit for bit; if a server provides a binary different from the one
10267 obtained locally, it may be either corrupt or malicious.
10269 We know that the hash that shows up in @file{/gnu/store} file names is
10270 the hash of all the inputs of the process that built the file or
10271 directory---compilers, libraries, build scripts,
10272 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10273 one store file name should map to exactly one build output.
10274 @command{guix challenge} checks whether there is, indeed, a single
10275 mapping by comparing the build outputs of several independent builds of
10276 any given store item.
10278 The command output looks like this:
10281 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10282 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10283 updating list of substitutes from 'https://guix.example.org'... 100.0%
10284 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10285 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10286 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10287 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10288 /gnu/store/@dots{}-git-2.5.0 contents differ:
10289 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10290 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10291 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10292 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10293 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10294 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10295 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10299 6,406 store items were analyzed:
10300 - 4,749 (74.1%) were identical
10301 - 525 (8.2%) differed
10302 - 1,132 (17.7%) were inconclusive
10306 In this example, @command{guix challenge} first scans the store to
10307 determine the set of locally-built derivations---as opposed to store
10308 items that were downloaded from a substitute server---and then queries
10309 all the substitute servers. It then reports those store items for which
10310 the servers obtained a result different from the local build.
10312 @cindex non-determinism, in package builds
10313 As an example, @code{guix.example.org} always gets a different answer.
10314 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10315 case of Git. This might indicate that the build process of Git is
10316 non-deterministic, meaning that its output varies as a function of
10317 various things that Guix does not fully control, in spite of building
10318 packages in isolated environments (@pxref{Features}). Most common
10319 sources of non-determinism include the addition of timestamps in build
10320 results, the inclusion of random numbers, and directory listings sorted
10321 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10324 To find out what is wrong with this Git binary, we can do something along
10325 these lines (@pxref{Invoking guix archive}):
10328 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
10329 | guix archive -x /tmp/git
10330 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10333 This command shows the difference between the files resulting from the
10334 local build, and the files resulting from the build on
10335 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10336 diffutils, Comparing and Merging Files}). The @command{diff} command
10337 works great for text files. When binary files differ, a better option
10338 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10339 visualize differences for all kinds of files.
10341 Once you have done that work, you can tell whether the differences are due
10342 to a non-deterministic build process or to a malicious server. We try
10343 hard to remove sources of non-determinism in packages to make it easier
10344 to verify substitutes, but of course, this is a process that
10345 involves not just Guix, but a large part of the free software community.
10346 In the meantime, @command{guix challenge} is one tool to help address
10349 If you are writing packages for Guix, you are encouraged to check
10350 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10351 same build result as you did with:
10354 $ guix challenge @var{package}
10358 where @var{package} is a package specification such as
10359 @code{guile@@2.0} or @code{glibc:debug}.
10361 The general syntax is:
10364 guix challenge @var{options} [@var{packages}@dots{}]
10367 When a difference is found between the hash of a locally-built item and
10368 that of a server-provided substitute, or among substitutes provided by
10369 different servers, the command displays it as in the example above and
10370 its exit code is 2 (other non-zero exit codes denote other kinds of
10373 The one option that matters is:
10377 @item --substitute-urls=@var{urls}
10378 Consider @var{urls} the whitespace-separated list of substitute source
10379 URLs to compare to.
10383 Show details about matches (identical contents) in addition to
10384 information about mismatches.
10388 @node Invoking guix copy
10389 @section Invoking @command{guix copy}
10391 @cindex copy, of store items, over SSH
10392 @cindex SSH, copy of store items
10393 @cindex sharing store items across machines
10394 @cindex transferring store items across machines
10395 The @command{guix copy} command copies items from the store of one
10396 machine to that of another machine over a secure shell (SSH)
10397 connection@footnote{This command is available only when Guile-SSH was
10398 found. @xref{Requirements}, for details.}. For example, the following
10399 command copies the @code{coreutils} package, the user's profile, and all
10400 their dependencies over to @var{host}, logged in as @var{user}:
10403 guix copy --to=@var{user}@@@var{host} \
10404 coreutils `readlink -f ~/.guix-profile`
10407 If some of the items to be copied are already present on @var{host},
10408 they are not actually sent.
10410 The command below retrieves @code{libreoffice} and @code{gimp} from
10411 @var{host}, assuming they are available there:
10414 guix copy --from=@var{host} libreoffice gimp
10417 The SSH connection is established using the Guile-SSH client, which is
10418 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10419 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10421 The key used to sign items that are sent must be accepted by the remote
10422 machine. Likewise, the key used by the remote machine to sign items you
10423 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10424 own daemon. @xref{Invoking guix archive}, for more information about
10425 store item authentication.
10427 The general syntax is:
10430 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10433 You must always specify one of the following options:
10436 @item --to=@var{spec}
10437 @itemx --from=@var{spec}
10438 Specify the host to send to or receive from. @var{spec} must be an SSH
10439 spec such as @code{example.org}, @code{charlie@@example.org}, or
10440 @code{charlie@@example.org:2222}.
10443 The @var{items} can be either package names, such as @code{gimp}, or
10444 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10446 When specifying the name of a package to send, it is first built if
10447 needed, unless @option{--dry-run} was specified. Common build options
10448 are supported (@pxref{Common Build Options}).
10451 @node Invoking guix container
10452 @section Invoking @command{guix container}
10454 @cindex @command{guix container}
10456 As of version @value{VERSION}, this tool is experimental. The interface
10457 is subject to radical change in the future.
10460 The purpose of @command{guix container} is to manipulate processes
10461 running within an isolated environment, commonly known as a
10462 ``container'', typically created by the @command{guix environment}
10463 (@pxref{Invoking guix environment}) and @command{guix system container}
10464 (@pxref{Invoking guix system}) commands.
10466 The general syntax is:
10469 guix container @var{action} @var{options}@dots{}
10472 @var{action} specifies the operation to perform with a container, and
10473 @var{options} specifies the context-specific arguments for the action.
10475 The following actions are available:
10479 Execute a command within the context of a running container.
10484 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10487 @var{pid} specifies the process ID of the running container.
10488 @var{program} specifies an executable file name within the root file
10489 system of the container. @var{arguments} are the additional options that
10490 will be passed to @var{program}.
10492 The following command launches an interactive login shell inside a
10493 Guix system container, started by @command{guix system container}, and whose
10494 process ID is 9001:
10497 guix container exec 9001 /run/current-system/profile/bin/bash --login
10500 Note that the @var{pid} cannot be the parent process of a container. It
10501 must be PID 1 of the container or one of its child processes.
10505 @node Invoking guix weather
10506 @section Invoking @command{guix weather}
10508 Occasionally you're grumpy because substitutes are lacking and you end
10509 up building packages by yourself (@pxref{Substitutes}). The
10510 @command{guix weather} command reports on substitute availability on the
10511 specified servers so you can have an idea of whether you'll be grumpy
10512 today. It can sometimes be useful info as a user, but it is primarily
10513 useful to people running @command{guix publish} (@pxref{Invoking guix
10516 @cindex statistics, for substitutes
10517 @cindex availability of substitutes
10518 @cindex substitute availability
10519 @cindex weather, substitute availability
10520 Here's a sample run:
10523 $ guix weather --substitute-urls=https://guix.example.org
10524 computing 5,872 package derivations for x86_64-linux...
10525 looking for 6,128 store items on https://guix.example.org..
10526 updating list of substitutes from 'https://guix.example.org'... 100.0%
10527 https://guix.example.org
10528 43.4% substitutes available (2,658 out of 6,128)
10529 7,032.5 MiB of nars (compressed)
10530 19,824.2 MiB on disk (uncompressed)
10531 0.030 seconds per request (182.9 seconds in total)
10532 33.5 requests per second
10534 9.8% (342 out of 3,470) of the missing items are queued
10536 x86_64-linux: 518 (59.7%)
10537 i686-linux: 221 (25.5%)
10538 aarch64-linux: 128 (14.8%)
10539 build rate: 23.41 builds per hour
10540 x86_64-linux: 11.16 builds per hour
10541 i686-linux: 6.03 builds per hour
10542 aarch64-linux: 6.41 builds per hour
10545 @cindex continuous integration, statistics
10546 As you can see, it reports the fraction of all the packages for which
10547 substitutes are available on the server---regardless of whether
10548 substitutes are enabled, and regardless of whether this server's signing
10549 key is authorized. It also reports the size of the compressed archives
10550 (``nars'') provided by the server, the size the corresponding store
10551 items occupy in the store (assuming deduplication is turned off), and
10552 the server's throughput. The second part gives continuous integration
10553 (CI) statistics, if the server supports it. In addition, using the
10554 @option{--coverage} option, @command{guix weather} can list ``important''
10555 package substitutes missing on the server (see below).
10557 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10558 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10559 challenge}, it ignores signatures on those substitutes, which is
10560 innocuous since the command only gathers statistics and cannot install
10563 The general syntax is:
10566 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10569 When @var{packages} is omitted, @command{guix weather} checks the availability
10570 of substitutes for @emph{all} the packages, or for those specified with
10571 @option{--manifest}; otherwise it only considers the specified packages. It
10572 is also possible to query specific system types with @option{--system}. The
10573 available options are listed below.
10576 @item --substitute-urls=@var{urls}
10577 @var{urls} is the space-separated list of substitute server URLs to
10578 query. When this option is omitted, the default set of substitute
10579 servers is queried.
10581 @item --system=@var{system}
10582 @itemx -s @var{system}
10583 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10584 option can be repeated, in which case @command{guix weather} will query
10585 substitutes for several system types.
10587 @item --manifest=@var{file}
10588 Instead of querying substitutes for all the packages, only ask for those
10589 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10590 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10593 @item --coverage[=@var{count}]
10594 @itemx -c [@var{count}]
10595 Report on substitute coverage for packages: list packages with at least
10596 @var{count} dependents (zero by default) for which substitutes are
10597 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10598 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10599 @var{b} usually lacks substitutes as well. The result looks like this:
10602 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10603 computing 8,983 package derivations for x86_64-linux...
10604 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10605 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10606 @value{SUBSTITUTE-URL}
10607 64.7% substitutes available (6,047 out of 9,343)
10609 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10610 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10611 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10612 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10616 What this example shows is that @code{kcoreaddons} and presumably the 58
10617 packages that depend on it have no substitutes at @code{ci.guix.info};
10618 likewise for @code{qgpgme} and the 46 packages that depend on it.
10620 If you are a Guix developer, or if you are taking care of this build farm,
10621 you'll probably want to have a closer look at these packages: they may simply
10625 @node Invoking guix processes
10626 @section Invoking @command{guix processes}
10628 The @command{guix processes} command can be useful to developers and system
10629 administrators, especially on multi-user machines and on build farms: it lists
10630 the current sessions (connections to the daemon), as well as information about
10631 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10632 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10633 listed.}. Here's an example of the information it returns:
10636 $ sudo guix processes
10639 ClientCommand: guix environment --ad-hoc python
10643 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10647 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10648 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10649 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10650 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10651 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10652 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10653 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10656 In this example we see that @command{guix-daemon} has three clients:
10657 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10658 integration tool; their process identifier (PID) is given by the
10659 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10660 @command{guix-daemon} sub-process of this particular session.
10662 The @code{LockHeld} fields show which store items are currently locked by this
10663 session, which corresponds to store items being built or substituted (the
10664 @code{LockHeld} field is not displayed when @command{guix processes} is not
10665 running as root.) Last, by looking at the @code{ChildProcess} field, we
10666 understand that these three builds are being offloaded (@pxref{Daemon Offload
10669 The output is in Recutils format so we can use the handy @command{recsel}
10670 command to select sessions of interest (@pxref{Selection Expressions,,,
10671 recutils, GNU recutils manual}). As an example, the command shows the command
10672 line and PID of the client that triggered the build of a Perl package:
10675 $ sudo guix processes | \
10676 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10678 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10681 @node System Configuration
10682 @chapter System Configuration
10684 @cindex system configuration
10685 Guix System supports a consistent whole-system configuration
10686 mechanism. By that we mean that all aspects of the global system
10687 configuration---such as the available system services, timezone and
10688 locale settings, user accounts---are declared in a single place. Such
10689 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10691 One of the advantages of putting all the system configuration under the
10692 control of Guix is that it supports transactional system upgrades, and
10693 makes it possible to roll back to a previous system instantiation,
10694 should something go wrong with the new one (@pxref{Features}). Another
10695 advantage is that it makes it easy to replicate the exact same configuration
10696 across different machines, or at different points in time, without
10697 having to resort to additional administration tools layered on top of
10698 the own tools of the system.
10699 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10701 This section describes this mechanism. First we focus on the system
10702 administrator's viewpoint---explaining how the system is configured and
10703 instantiated. Then we show how this mechanism can be extended, for
10704 instance to support new system services.
10707 * Using the Configuration System:: Customizing your GNU system.
10708 * operating-system Reference:: Detail of operating-system declarations.
10709 * File Systems:: Configuring file system mounts.
10710 * Mapped Devices:: Block device extra processing.
10711 * User Accounts:: Specifying user accounts.
10712 * Keyboard Layout:: How the system interprets key strokes.
10713 * Locales:: Language and cultural convention settings.
10714 * Services:: Specifying system services.
10715 * Setuid Programs:: Programs running with root privileges.
10716 * X.509 Certificates:: Authenticating HTTPS servers.
10717 * Name Service Switch:: Configuring libc's name service switch.
10718 * Initial RAM Disk:: Linux-Libre bootstrapping.
10719 * Bootloader Configuration:: Configuring the boot loader.
10720 * Invoking guix system:: Instantiating a system configuration.
10721 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10722 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10723 * Defining Services:: Adding new service definitions.
10726 @node Using the Configuration System
10727 @section Using the Configuration System
10729 The operating system is configured by providing an
10730 @code{operating-system} declaration in a file that can then be passed to
10731 the @command{guix system} command (@pxref{Invoking guix system}). A
10732 simple setup, with the default system services, the default Linux-Libre
10733 kernel, initial RAM disk, and boot loader looks like this:
10735 @findex operating-system
10737 @include os-config-bare-bones.texi
10740 This example should be self-describing. Some of the fields defined
10741 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10742 Others, such as @code{packages} and @code{services}, can be omitted, in
10743 which case they get a default value.
10745 Below we discuss the effect of some of the most important fields
10746 (@pxref{operating-system Reference}, for details about all the available
10747 fields), and how to @dfn{instantiate} the operating system using
10748 @command{guix system}.
10750 @unnumberedsubsec Bootloader
10752 @cindex legacy boot, on Intel machines
10753 @cindex BIOS boot, on Intel machines
10756 The @code{bootloader} field describes the method that will be used to boot
10757 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10758 mode, as in the example above. However, more recent machines rely instead on
10759 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10760 the @code{bootloader} field should contain something along these lines:
10763 (bootloader-configuration
10764 (bootloader grub-efi-bootloader)
10765 (target "/boot/efi"))
10768 @xref{Bootloader Configuration}, for more information on the available
10769 configuration options.
10771 @unnumberedsubsec Globally-Visible Packages
10773 @vindex %base-packages
10774 The @code{packages} field lists packages that will be globally visible
10775 on the system, for all user accounts---i.e., in every user's @code{PATH}
10776 environment variable---in addition to the per-user profiles
10777 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10778 provides all the tools one would expect for basic user and administrator
10779 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10780 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10781 etc. The example above adds GNU@tie{}Screen to those,
10782 taken from the @code{(gnu packages screen)}
10783 module (@pxref{Package Modules}). The
10784 @code{(list package output)} syntax can be used to add a specific output
10788 (use-modules (gnu packages))
10789 (use-modules (gnu packages dns))
10793 (packages (cons (list bind "utils")
10797 @findex specification->package
10798 Referring to packages by variable name, like @code{bind} above, has
10799 the advantage of being unambiguous; it also allows typos and such to be
10800 diagnosed right away as ``unbound variables''. The downside is that one
10801 needs to know which module defines which package, and to augment the
10802 @code{use-package-modules} line accordingly. To avoid that, one can use
10803 the @code{specification->package} procedure of the @code{(gnu packages)}
10804 module, which returns the best package for a given name or name and
10808 (use-modules (gnu packages))
10812 (packages (append (map specification->package
10813 '("tcpdump" "htop" "gnupg@@2.0"))
10817 @unnumberedsubsec System Services
10820 @vindex %base-services
10821 The @code{services} field lists @dfn{system services} to be made
10822 available when the system starts (@pxref{Services}).
10823 The @code{operating-system} declaration above specifies that, in
10824 addition to the basic services, we want the OpenSSH secure shell
10825 daemon listening on port 2222 (@pxref{Networking Services,
10826 @code{openssh-service-type}}). Under the hood,
10827 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10828 right command-line options, possibly with supporting configuration files
10829 generated as needed (@pxref{Defining Services}).
10831 @cindex customization, of services
10832 @findex modify-services
10833 Occasionally, instead of using the base services as is, you will want to
10834 customize them. To do this, use @code{modify-services} (@pxref{Service
10835 Reference, @code{modify-services}}) to modify the list.
10837 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10838 (the console log-in) in the @code{%base-services} list (@pxref{Base
10839 Services, @code{%base-services}}). To do that, you can write the
10840 following in your operating system declaration:
10843 (define %my-services
10844 ;; My very own list of services.
10845 (modify-services %base-services
10846 (guix-service-type config =>
10847 (guix-configuration
10849 (use-substitutes? #f)
10850 (extra-options '("--gc-keep-derivations"))))
10851 (mingetty-service-type config =>
10852 (mingetty-configuration
10853 (inherit config)))))
10857 (services %my-services))
10860 This changes the configuration---i.e., the service parameters---of the
10861 @code{guix-service-type} instance, and that of all the
10862 @code{mingetty-service-type} instances in the @code{%base-services} list.
10863 Observe how this is accomplished: first, we arrange for the original
10864 configuration to be bound to the identifier @code{config} in the
10865 @var{body}, and then we write the @var{body} so that it evaluates to the
10866 desired configuration. In particular, notice how we use @code{inherit}
10867 to create a new configuration which has the same values as the old
10868 configuration, but with a few modifications.
10870 @cindex encrypted disk
10871 The configuration for a typical ``desktop'' usage, with an encrypted
10872 root partition, the X11 display
10873 server, GNOME and Xfce (users can choose which of these desktop
10874 environments to use at the log-in screen by pressing @kbd{F1}), network
10875 management, power management, and more, would look like this:
10878 @include os-config-desktop.texi
10881 A graphical system with a choice of lightweight window managers
10882 instead of full-blown desktop environments would look like this:
10885 @include os-config-lightweight-desktop.texi
10888 This example refers to the @file{/boot/efi} file system by its UUID,
10889 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10890 as returned by the @command{blkid} command.
10892 @xref{Desktop Services}, for the exact list of services provided by
10893 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10894 information about the @code{nss-certs} package that is used here.
10896 Again, @code{%desktop-services} is just a list of service objects. If
10897 you want to remove services from there, you can do so using the
10898 procedures for list filtering (@pxref{SRFI-1 Filtering and
10899 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10900 following expression returns a list that contains all the services in
10901 @code{%desktop-services} minus the Avahi service:
10904 (remove (lambda (service)
10905 (eq? (service-kind service) avahi-service-type))
10909 @unnumberedsubsec Instantiating the System
10911 Assuming the @code{operating-system} declaration
10912 is stored in the @file{my-system-config.scm}
10913 file, the @command{guix system reconfigure my-system-config.scm} command
10914 instantiates that configuration, and makes it the default GRUB boot
10915 entry (@pxref{Invoking guix system}).
10917 The normal way to change the system configuration is by updating this
10918 file and re-running @command{guix system reconfigure}. One should never
10919 have to touch files in @file{/etc} or to run commands that modify the
10920 system state such as @command{useradd} or @command{grub-install}. In
10921 fact, you must avoid that since that would not only void your warranty
10922 but also prevent you from rolling back to previous versions of your
10923 system, should you ever need to.
10925 @cindex roll-back, of the operating system
10926 Speaking of roll-back, each time you run @command{guix system
10927 reconfigure}, a new @dfn{generation} of the system is created---without
10928 modifying or deleting previous generations. Old system generations get
10929 an entry in the bootloader boot menu, allowing you to boot them in case
10930 something went wrong with the latest generation. Reassuring, no? The
10931 @command{guix system list-generations} command lists the system
10932 generations available on disk. It is also possible to roll back the
10933 system via the commands @command{guix system roll-back} and
10934 @command{guix system switch-generation}.
10936 Although the @command{guix system reconfigure} command will not modify
10937 previous generations, you must take care when the current generation is not
10938 the latest (e.g., after invoking @command{guix system roll-back}), since
10939 the operation might overwrite a later generation (@pxref{Invoking guix
10942 @unnumberedsubsec The Programming Interface
10944 At the Scheme level, the bulk of an @code{operating-system} declaration
10945 is instantiated with the following monadic procedure (@pxref{The Store
10948 @deffn {Monadic Procedure} operating-system-derivation os
10949 Return a derivation that builds @var{os}, an @code{operating-system}
10950 object (@pxref{Derivations}).
10952 The output of the derivation is a single directory that refers to all
10953 the packages, configuration files, and other supporting files needed to
10954 instantiate @var{os}.
10957 This procedure is provided by the @code{(gnu system)} module. Along
10958 with @code{(gnu services)} (@pxref{Services}), this module contains the
10959 guts of Guix System. Make sure to visit it!
10962 @node operating-system Reference
10963 @section @code{operating-system} Reference
10965 This section summarizes all the options available in
10966 @code{operating-system} declarations (@pxref{Using the Configuration
10969 @deftp {Data Type} operating-system
10970 This is the data type representing an operating system configuration.
10971 By that, we mean all the global system configuration, not per-user
10972 configuration (@pxref{Using the Configuration System}).
10975 @item @code{kernel} (default: @var{linux-libre})
10976 The package object of the operating system kernel to use@footnote{Currently
10977 only the Linux-libre kernel is supported. In the future, it will be
10978 possible to use the GNU@tie{}Hurd.}.
10980 @item @code{kernel-arguments} (default: @code{'("quiet")})
10981 List of strings or gexps representing additional arguments to pass on
10982 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10984 @item @code{bootloader}
10985 The system bootloader configuration object. @xref{Bootloader Configuration}.
10988 This is the label (a string) as it appears in the bootloader's menu entry.
10989 The default label includes the kernel name and version.
10991 @item @code{keyboard-layout} (default: @code{#f})
10992 This field specifies the keyboard layout to use in the console. It can be
10993 either @code{#f}, in which case the default keyboard layout is used (usually
10994 US English), or a @code{<keyboard-layout>} record.
10996 This keyboard layout is in effect as soon as the kernel has booted. For
10997 instance, it is the keyboard layout in effect when you type a passphrase if
10998 your root file system is on a @code{luks-device-mapping} mapped device
10999 (@pxref{Mapped Devices}).
11002 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11003 that used by the graphical display server. @xref{Bootloader Configuration},
11004 for information on how to specify the bootloader's keyboard layout. @xref{X
11005 Window}, for information on how to specify the keyboard layout used by the X
11009 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11011 @cindex initial RAM disk
11012 The list of Linux kernel modules that need to be available in the
11013 initial RAM disk. @xref{Initial RAM Disk}.
11015 @item @code{initrd} (default: @code{base-initrd})
11016 A procedure that returns an initial RAM disk for the Linux
11017 kernel. This field is provided to support low-level customization and
11018 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11020 @item @code{firmware} (default: @code{%base-firmware})
11022 List of firmware packages loadable by the operating system kernel.
11024 The default includes firmware needed for Atheros- and Broadcom-based
11025 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11026 respectively). @xref{Hardware Considerations}, for more info on
11027 supported hardware.
11029 @item @code{host-name}
11032 @item @code{hosts-file}
11034 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11035 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11036 Reference Manual}). The default is a file with entries for
11037 @code{localhost} and @var{host-name}.
11039 @item @code{mapped-devices} (default: @code{'()})
11040 A list of mapped devices. @xref{Mapped Devices}.
11042 @item @code{file-systems}
11043 A list of file systems. @xref{File Systems}.
11045 @item @code{swap-devices} (default: @code{'()})
11046 @cindex swap devices
11047 A list of strings identifying devices or files to be used for ``swap
11048 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11049 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11050 It is possible to specify a swap file in a file system on a mapped
11051 device, provided that the necessary device mapping and file system are
11052 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11054 @item @code{users} (default: @code{%base-user-accounts})
11055 @itemx @code{groups} (default: @code{%base-groups})
11056 List of user accounts and groups. @xref{User Accounts}.
11058 If the @code{users} list lacks a user account with UID@tie{}0, a
11059 ``root'' account with UID@tie{}0 is automatically added.
11061 @item @code{skeletons} (default: @code{(default-skeletons)})
11062 A list target file name/file-like object tuples (@pxref{G-Expressions,
11063 file-like objects}). These are the skeleton files that will be added to
11064 the home directory of newly-created user accounts.
11066 For instance, a valid value may look like this:
11069 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11070 (".guile" ,(plain-file "guile"
11071 "(use-modules (ice-9 readline))
11072 (activate-readline)")))
11075 @item @code{issue} (default: @code{%default-issue})
11076 A string denoting the contents of the @file{/etc/issue} file, which is
11077 displayed when users log in on a text console.
11079 @item @code{packages} (default: @code{%base-packages})
11080 The set of packages installed in the global profile, which is accessible
11081 at @file{/run/current-system/profile}.
11083 The default set includes core utilities and it is good practice to
11084 install non-core utilities in user profiles (@pxref{Invoking guix
11087 @item @code{timezone}
11088 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11090 You can run the @command{tzselect} command to find out which timezone
11091 string corresponds to your region. Choosing an invalid timezone name
11092 causes @command{guix system} to fail.
11094 @item @code{locale} (default: @code{"en_US.utf8"})
11095 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11096 Library Reference Manual}). @xref{Locales}, for more information.
11098 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11099 The list of locale definitions to be compiled and that may be used at
11100 run time. @xref{Locales}.
11102 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11103 The list of GNU@tie{}libc packages whose locale data and tools are used
11104 to build the locale definitions. @xref{Locales}, for compatibility
11105 considerations that justify this option.
11107 @item @code{name-service-switch} (default: @code{%default-nss})
11108 Configuration of the libc name service switch (NSS)---a
11109 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11112 @item @code{services} (default: @code{%base-services})
11113 A list of service objects denoting system services. @xref{Services}.
11115 @cindex essential services
11116 @item @code{essential-services} (default: ...)
11117 The list of ``essential services''---i.e., things like instances of
11118 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11119 Reference}), which are derived from the operating system definition itself.
11120 As a user you should @emph{never} need to touch this field.
11122 @item @code{pam-services} (default: @code{(base-pam-services)})
11124 @cindex pluggable authentication modules
11125 Linux @dfn{pluggable authentication module} (PAM) services.
11126 @c FIXME: Add xref to PAM services section.
11128 @item @code{setuid-programs} (default: @var{%setuid-programs})
11129 List of string-valued G-expressions denoting setuid programs.
11130 @xref{Setuid Programs}.
11132 @item @code{sudoers-file} (default: @var{%sudoers-specification})
11133 @cindex sudoers file
11134 The contents of the @file{/etc/sudoers} file as a file-like object
11135 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11137 This file specifies which users can use the @command{sudo} command, what
11138 they are allowed to do, and what privileges they may gain. The default
11139 is that only @code{root} and members of the @code{wheel} group may use
11144 @deffn {Scheme Syntax} this-operating-system
11145 When used in the @emph{lexical scope} of an operating system field definition,
11146 this identifier resolves to the operating system being defined.
11148 The example below shows how to refer to the operating system being defined in
11149 the definition of the @code{label} field:
11152 (use-modules (gnu) (guix))
11156 (label (package-full-name
11157 (operating-system-kernel this-operating-system))))
11160 It is an error to refer to @code{this-operating-system} outside an operating
11167 @section File Systems
11169 The list of file systems to be mounted is specified in the
11170 @code{file-systems} field of the operating system declaration
11171 (@pxref{Using the Configuration System}). Each file system is declared
11172 using the @code{file-system} form, like this:
11176 (mount-point "/home")
11177 (device "/dev/sda3")
11181 As usual, some of the fields are mandatory---those shown in the example
11182 above---while others can be omitted. These are described below.
11184 @deftp {Data Type} file-system
11185 Objects of this type represent file systems to be mounted. They
11186 contain the following members:
11190 This is a string specifying the type of the file system---e.g.,
11193 @item @code{mount-point}
11194 This designates the place where the file system is to be mounted.
11196 @item @code{device}
11197 This names the ``source'' of the file system. It can be one of three
11198 things: a file system label, a file system UUID, or the name of a
11199 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11200 systems without having to hard-code their actual device
11201 name@footnote{Note that, while it is tempting to use
11202 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11203 result, this is not recommended: These special device nodes are created
11204 by the udev daemon and may be unavailable at the time the device is
11207 @findex file-system-label
11208 File system labels are created using the @code{file-system-label}
11209 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11210 plain strings. Here's an example of a file system referred to by its
11211 label, as shown by the @command{e2label} command:
11215 (mount-point "/home")
11217 (device (file-system-label "my-home")))
11221 UUIDs are converted from their string representation (as shown by the
11222 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11223 @code{uuid} form expects 16-byte UUIDs as defined in
11224 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11225 form of UUID used by the ext2 family of file systems and others, but it
11226 is different from ``UUIDs'' found in FAT file systems, for instance.},
11231 (mount-point "/home")
11233 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11236 When the source of a file system is a mapped device (@pxref{Mapped
11237 Devices}), its @code{device} field @emph{must} refer to the mapped
11238 device name---e.g., @file{"/dev/mapper/root-partition"}.
11239 This is required so that
11240 the system knows that mounting the file system depends on having the
11241 corresponding device mapping established.
11243 @item @code{flags} (default: @code{'()})
11244 This is a list of symbols denoting mount flags. Recognized flags
11245 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11246 access to special files), @code{no-suid} (ignore setuid and setgid
11247 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
11248 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
11249 Library Reference Manual}, for more information on these flags.
11251 @item @code{options} (default: @code{#f})
11252 This is either @code{#f}, or a string denoting mount options passed to the
11253 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11254 Reference Manual}, for details and run @command{man 8 mount} for options for
11255 various file systems.
11257 @item @code{mount?} (default: @code{#t})
11258 This value indicates whether to automatically mount the file system when
11259 the system is brought up. When set to @code{#f}, the file system gets
11260 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11261 is not automatically mounted.
11263 @item @code{needed-for-boot?} (default: @code{#f})
11264 This Boolean value indicates whether the file system is needed when
11265 booting. If that is true, then the file system is mounted when the
11266 initial RAM disk (initrd) is loaded. This is always the case, for
11267 instance, for the root file system.
11269 @item @code{check?} (default: @code{#t})
11270 This Boolean indicates whether the file system needs to be checked for
11271 errors before being mounted.
11273 @item @code{create-mount-point?} (default: @code{#f})
11274 When true, the mount point is created if it does not exist yet.
11276 @item @code{dependencies} (default: @code{'()})
11277 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11278 representing file systems that must be mounted or mapped devices that
11279 must be opened before (and unmounted or closed after) this one.
11281 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11282 a dependency of @file{/sys/fs/cgroup/cpu} and
11283 @file{/sys/fs/cgroup/memory}.
11285 Another example is a file system that depends on a mapped device, for
11286 example for an encrypted partition (@pxref{Mapped Devices}).
11290 The @code{(gnu system file-systems)} exports the following useful
11293 @defvr {Scheme Variable} %base-file-systems
11294 These are essential file systems that are required on normal systems,
11295 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
11296 below.) Operating system declarations should always contain at least
11300 @defvr {Scheme Variable} %pseudo-terminal-file-system
11301 This is the file system to be mounted as @file{/dev/pts}. It supports
11302 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11303 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11304 Manual}). Pseudo-terminals are used by terminal emulators such as
11308 @defvr {Scheme Variable} %shared-memory-file-system
11309 This file system is mounted as @file{/dev/shm} and is used to support
11310 memory sharing across processes (@pxref{Memory-mapped I/O,
11311 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11314 @defvr {Scheme Variable} %immutable-store
11315 This file system performs a read-only ``bind mount'' of
11316 @file{/gnu/store}, making it read-only for all the users including
11317 @code{root}. This prevents against accidental modification by software
11318 running as @code{root} or by system administrators.
11320 The daemon itself is still able to write to the store: it remounts it
11321 read-write in its own ``name space.''
11324 @defvr {Scheme Variable} %binary-format-file-system
11325 The @code{binfmt_misc} file system, which allows handling of arbitrary
11326 executable file types to be delegated to user space. This requires the
11327 @code{binfmt.ko} kernel module to be loaded.
11330 @defvr {Scheme Variable} %fuse-control-file-system
11331 The @code{fusectl} file system, which allows unprivileged users to mount
11332 and unmount user-space FUSE file systems. This requires the
11333 @code{fuse.ko} kernel module to be loaded.
11336 @node Mapped Devices
11337 @section Mapped Devices
11339 @cindex device mapping
11340 @cindex mapped devices
11341 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11342 such as a hard disk partition, can be @dfn{mapped} into another device,
11343 usually in @code{/dev/mapper/},
11344 with additional processing over the data that flows through
11345 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11346 concept of a ``mapped device'' and that of a file system: both boil down
11347 to @emph{translating} input/output operations made on a file to
11348 operations on its backing store. Thus, the Hurd implements mapped
11349 devices, like file systems, using the generic @dfn{translator} mechanism
11350 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11351 typical example is encryption device mapping: all writes to the mapped
11352 device are encrypted, and all reads are deciphered, transparently.
11353 Guix extends this notion by considering any device or set of devices that
11354 are @dfn{transformed} in some way to create a new device; for instance,
11355 RAID devices are obtained by @dfn{assembling} several other devices, such
11356 as hard disks or partitions, into a new one that behaves as one partition.
11357 Other examples, not yet implemented, are LVM logical volumes.
11359 Mapped devices are declared using the @code{mapped-device} form,
11360 defined as follows; for examples, see below.
11362 @deftp {Data Type} mapped-device
11363 Objects of this type represent device mappings that will be made when
11364 the system boots up.
11368 This is either a string specifying the name of the block device to be mapped,
11369 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11370 need to be assembled for creating a new one.
11373 This string specifies the name of the resulting mapped device. For
11374 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11375 specifying @code{"my-partition"} leads to the creation of
11376 the @code{"/dev/mapper/my-partition"} device.
11377 For RAID devices of type @code{raid-device-mapping}, the full device name
11378 such as @code{"/dev/md0"} needs to be given.
11381 This must be a @code{mapped-device-kind} object, which specifies how
11382 @var{source} is mapped to @var{target}.
11386 @defvr {Scheme Variable} luks-device-mapping
11387 This defines LUKS block device encryption using the @command{cryptsetup}
11388 command from the package with the same name. It relies on the
11389 @code{dm-crypt} Linux kernel module.
11392 @defvr {Scheme Variable} raid-device-mapping
11393 This defines a RAID device, which is assembled using the @code{mdadm}
11394 command from the package with the same name. It requires a Linux kernel
11395 module for the appropriate RAID level to be loaded, such as @code{raid456}
11396 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11399 @cindex disk encryption
11401 The following example specifies a mapping from @file{/dev/sda3} to
11402 @file{/dev/mapper/home} using LUKS---the
11403 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11404 standard mechanism for disk encryption.
11405 The @file{/dev/mapper/home}
11406 device can then be used as the @code{device} of a @code{file-system}
11407 declaration (@pxref{File Systems}).
11411 (source "/dev/sda3")
11413 (type luks-device-mapping))
11416 Alternatively, to become independent of device numbering, one may obtain
11417 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11421 cryptsetup luksUUID /dev/sda3
11424 and use it as follows:
11428 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11430 (type luks-device-mapping))
11433 @cindex swap encryption
11434 It is also desirable to encrypt swap space, since swap space may contain
11435 sensitive data. One way to accomplish that is to use a swap file in a
11436 file system on a device mapped via LUKS encryption. In this way, the
11437 swap file is encrypted because the entire device is encrypted.
11438 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11440 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11441 may be declared as follows:
11445 (source (list "/dev/sda1" "/dev/sdb1"))
11446 (target "/dev/md0")
11447 (type raid-device-mapping))
11450 The @file{/dev/md0} device can then be used as the @code{device} of a
11451 @code{file-system} declaration (@pxref{File Systems}).
11452 Note that the RAID level need not be given; it is chosen during the
11453 initial creation and formatting of the RAID device and is determined
11454 automatically later.
11457 @node User Accounts
11458 @section User Accounts
11462 @cindex user accounts
11463 User accounts and groups are entirely managed through the
11464 @code{operating-system} declaration. They are specified with the
11465 @code{user-account} and @code{user-group} forms:
11471 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11472 "audio" ;sound card
11473 "video" ;video devices such as webcams
11474 "cdrom")) ;the good ol' CD-ROM
11475 (comment "Bob's sister")
11476 (home-directory "/home/alice"))
11479 When booting or upon completion of @command{guix system reconfigure},
11480 the system ensures that only the user accounts and groups specified in
11481 the @code{operating-system} declaration exist, and with the specified
11482 properties. Thus, account or group creations or modifications made by
11483 directly invoking commands such as @command{useradd} are lost upon
11484 reconfiguration or reboot. This ensures that the system remains exactly
11487 @deftp {Data Type} user-account
11488 Objects of this type represent user accounts. The following members may
11493 The name of the user account.
11497 This is the name (a string) or identifier (a number) of the user group
11498 this account belongs to.
11500 @item @code{supplementary-groups} (default: @code{'()})
11501 Optionally, this can be defined as a list of group names that this
11502 account belongs to.
11504 @item @code{uid} (default: @code{#f})
11505 This is the user ID for this account (a number), or @code{#f}. In the
11506 latter case, a number is automatically chosen by the system when the
11507 account is created.
11509 @item @code{comment} (default: @code{""})
11510 A comment about the account, such as the account owner's full name.
11512 @item @code{home-directory}
11513 This is the name of the home directory for the account.
11515 @item @code{create-home-directory?} (default: @code{#t})
11516 Indicates whether the home directory of this account should be created
11517 if it does not exist yet.
11519 @item @code{shell} (default: Bash)
11520 This is a G-expression denoting the file name of a program to be used as
11521 the shell (@pxref{G-Expressions}).
11523 @item @code{system?} (default: @code{#f})
11524 This Boolean value indicates whether the account is a ``system''
11525 account. System accounts are sometimes treated specially; for instance,
11526 graphical login managers do not list them.
11528 @anchor{user-account-password}
11529 @cindex password, for user accounts
11530 @item @code{password} (default: @code{#f})
11531 You would normally leave this field to @code{#f}, initialize user
11532 passwords as @code{root} with the @command{passwd} command, and then let
11533 users change it with @command{passwd}. Passwords set with
11534 @command{passwd} are of course preserved across reboot and
11537 If you @emph{do} want to set an initial password for an account, then
11538 this field must contain the encrypted password, as a string. You can use the
11539 @code{crypt} procedure for this purpose:
11546 ;; Specify a SHA-512-hashed initial password.
11547 (password (crypt "InitialPassword!" "$6$abc")))
11551 The hash of this initial password will be available in a file in
11552 @file{/gnu/store}, readable by all the users, so this method must be used with
11556 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11557 more information on password encryption, and @ref{Encryption,,, guile, GNU
11558 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11564 User group declarations are even simpler:
11567 (user-group (name "students"))
11570 @deftp {Data Type} user-group
11571 This type is for, well, user groups. There are just a few fields:
11575 The name of the group.
11577 @item @code{id} (default: @code{#f})
11578 The group identifier (a number). If @code{#f}, a new number is
11579 automatically allocated when the group is created.
11581 @item @code{system?} (default: @code{#f})
11582 This Boolean value indicates whether the group is a ``system'' group.
11583 System groups have low numerical IDs.
11585 @item @code{password} (default: @code{#f})
11586 What, user groups can have a password? Well, apparently yes. Unless
11587 @code{#f}, this field specifies the password of the group.
11592 For convenience, a variable lists all the basic user groups one may
11595 @defvr {Scheme Variable} %base-groups
11596 This is the list of basic user groups that users and/or packages expect
11597 to be present on the system. This includes groups such as ``root'',
11598 ``wheel'', and ``users'', as well as groups used to control access to
11599 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11602 @defvr {Scheme Variable} %base-user-accounts
11603 This is the list of basic system accounts that programs may expect to
11604 find on a GNU/Linux system, such as the ``nobody'' account.
11606 Note that the ``root'' account is not included here. It is a
11607 special-case and is automatically added whether or not it is specified.
11610 @node Keyboard Layout
11611 @section Keyboard Layout
11613 @cindex keyboard layout
11615 To specify what each key of your keyboard does, you need to tell the operating
11616 system what @dfn{keyboard layout} you want to use. The default, when nothing
11617 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11618 However, German speakers will usually prefer the German QWERTZ layout, French
11619 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11620 or bépo, and they might even want to further customize the effect of some of
11621 the keys. This section explains how to get that done.
11623 @cindex keyboard layout, definition
11624 There are three components that will want to know about your keyboard layout:
11628 The @emph{bootloader} may want to know what keyboard layout you want to use
11629 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11630 you want, for instance, to make sure that you can type the passphrase of your
11631 encrypted root partition using the right layout.
11634 The @emph{operating system kernel}, Linux, will need that so that the console
11635 is properly configured (@pxref{operating-system Reference,
11636 @code{keyboard-layout}}).
11639 The @emph{graphical display server}, usually Xorg, also has its own idea of
11640 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11643 Guix allows you to configure all three separately but, fortunately, it allows
11644 you to share the same keyboard layout for all three components.
11646 @cindex XKB, keyboard layouts
11647 Keyboard layouts are represented by records created by the
11648 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11649 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11650 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11651 optional variant name, an optional keyboard model name, and a possibly empty
11652 list of additional options. In most cases the layout name is all you care
11653 about. Here are a few example:
11656 ;; The German QWERTZ layout. Here we assume a standard
11657 ;; "pc105" keyboard model.
11658 (keyboard-layout "de")
11660 ;; The bépo variant of the French layout.
11661 (keyboard-layout "fr" "bepo")
11663 ;; The Catalan layout.
11664 (keyboard-layout "es" "cat")
11666 ;; The Latin American Spanish layout. In addition, the
11667 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11668 ;; and the "Menu" key is used as a "Compose" key to enter
11669 ;; accented letters.
11670 (keyboard-layout "latam"
11671 #:options '("ctrl:nocaps" "compose:menu"))
11673 ;; The Russian layout for a ThinkPad keyboard.
11674 (keyboard-layout "ru" #:model "thinkpad")
11676 ;; The "US international" layout, which is the US layout plus
11677 ;; dead keys to enter accented characters. This is for an
11678 ;; Apple MacBook keyboard.
11679 (keyboard-layout "us" "intl" #:model "macbook78")
11682 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11683 for a complete list of supported layouts, variants, and models.
11685 @cindex keyboard layout, configuration
11686 Let's say you want your system to use the Turkish keyboard layout throughout
11687 your system---bootloader, console, and Xorg. Here's what your system
11688 configuration would look like:
11690 @findex set-xorg-configuration
11692 ;; Using the Turkish layout for the bootloader, the console,
11697 (keyboard-layout (keyboard-layout "tr")) ;for the console
11698 (bootloader (bootloader-configuration
11699 (bootloader grub-efi-bootloader)
11700 (target "/boot/efi")
11701 (keyboard-layout keyboard-layout))) ;for GRUB
11702 (services (cons (set-xorg-configuration
11703 (xorg-configuration ;for Xorg
11704 (keyboard-layout keyboard-layout)))
11705 %desktop-services)))
11708 In the example above, for GRUB and for Xorg, we just refer to the
11709 @code{keyboard-layout} field defined above, but we could just as well refer to
11710 a different layout. The @code{set-xorg-configuration} procedure communicates
11711 the desired Xorg configuration to the graphical log-in manager, by default
11714 We've discussed how to specify the @emph{default} keyboard layout of your
11715 system when it starts, but you can also adjust it at run time:
11719 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11720 where you can select one or more keyboard layouts.
11723 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11724 allows you to change the current layout. For example, this is how you would
11725 change the layout to US Dvorak:
11728 setxkbmap us dvorak
11732 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11733 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11734 keyboard layout categorization described above. The command below loads the
11735 French bépo layout:
11746 A @dfn{locale} defines cultural conventions for a particular language
11747 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11748 Reference Manual}). Each locale has a name that typically has the form
11749 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11750 @code{fr_LU.utf8} designates the locale for the French language, with
11751 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11753 @cindex locale definition
11754 Usually, you will want to specify the default locale for the machine
11755 using the @code{locale} field of the @code{operating-system} declaration
11756 (@pxref{operating-system Reference, @code{locale}}).
11758 The selected locale is automatically added to the @dfn{locale
11759 definitions} known to the system if needed, with its codeset inferred
11760 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11761 @code{UTF-8} codeset. Additional locale definitions can be specified in
11762 the @code{locale-definitions} slot of @code{operating-system}---this is
11763 useful, for instance, if the codeset could not be inferred from the
11764 locale name. The default set of locale definitions includes some widely
11765 used locales, but not all the available locales, in order to save space.
11767 For instance, to add the North Frisian locale for Germany, the value of
11771 (cons (locale-definition
11772 (name "fy_DE.utf8") (source "fy_DE"))
11773 %default-locale-definitions)
11776 Likewise, to save space, one might want @code{locale-definitions} to
11777 list only the locales that are actually used, as in:
11780 (list (locale-definition
11781 (name "ja_JP.eucjp") (source "ja_JP")
11782 (charset "EUC-JP")))
11786 The compiled locale definitions are available at
11787 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11788 version, which is the default location where the GNU@tie{}libc provided
11789 by Guix looks for locale data. This can be overridden using the
11790 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11791 @code{LOCPATH} and locale packages}).
11793 The @code{locale-definition} form is provided by the @code{(gnu system
11794 locale)} module. Details are given below.
11796 @deftp {Data Type} locale-definition
11797 This is the data type of a locale definition.
11802 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11803 Reference Manual}, for more information on locale names.
11805 @item @code{source}
11806 The name of the source for that locale. This is typically the
11807 @code{@var{language}_@var{territory}} part of the locale name.
11809 @item @code{charset} (default: @code{"UTF-8"})
11810 The ``character set'' or ``code set'' for that locale,
11811 @uref{https://www.iana.org/assignments/character-sets, as defined by
11817 @defvr {Scheme Variable} %default-locale-definitions
11818 A list of commonly used UTF-8 locales, used as the default
11819 value of the @code{locale-definitions} field of @code{operating-system}
11822 @cindex locale name
11823 @cindex normalized codeset in locale names
11824 These locale definitions use the @dfn{normalized codeset} for the part
11825 that follows the dot in the name (@pxref{Using gettextized software,
11826 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11827 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11828 @code{uk_UA.UTF-8}.
11831 @subsection Locale Data Compatibility Considerations
11833 @cindex incompatibility, of locale data
11834 @code{operating-system} declarations provide a @code{locale-libcs} field
11835 to specify the GNU@tie{}libc packages that are used to compile locale
11836 declarations (@pxref{operating-system Reference}). ``Why would I
11837 care?'', you may ask. Well, it turns out that the binary format of
11838 locale data is occasionally incompatible from one libc version to
11841 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11842 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11843 For instance, a program linked against libc version 2.21 is unable to
11844 read locale data produced with libc 2.22; worse, that program
11845 @emph{aborts} instead of simply ignoring the incompatible locale
11846 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11847 the incompatible locale data, which is already an improvement.}.
11848 Similarly, a program linked against libc 2.22 can read most, but not
11849 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11850 data is incompatible); thus calls to @code{setlocale} may fail, but
11851 programs will not abort.
11853 The ``problem'' with Guix is that users have a lot of freedom: They can
11854 choose whether and when to upgrade software in their profiles, and might
11855 be using a libc version different from the one the system administrator
11856 used to build the system-wide locale data.
11858 Fortunately, unprivileged users can also install their own locale data
11859 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11860 @code{GUIX_LOCPATH} and locale packages}).
11862 Still, it is best if the system-wide locale data at
11863 @file{/run/current-system/locale} is built for all the libc versions
11864 actually in use on the system, so that all the programs can access
11865 it---this is especially crucial on a multi-user system. To do that, the
11866 administrator can specify several libc packages in the
11867 @code{locale-libcs} field of @code{operating-system}:
11870 (use-package-modules base)
11874 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11877 This example would lead to a system containing locale definitions for
11878 both libc 2.21 and the current version of libc in
11879 @file{/run/current-system/locale}.
11885 @cindex system services
11886 An important part of preparing an @code{operating-system} declaration is
11887 listing @dfn{system services} and their configuration (@pxref{Using the
11888 Configuration System}). System services are typically daemons launched
11889 when the system boots, or other actions needed at that time---e.g.,
11890 configuring network access.
11892 Guix has a broad definition of ``service'' (@pxref{Service
11893 Composition}), but many services are managed by the GNU@tie{}Shepherd
11894 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11895 command allows you to list the available services, show their status,
11896 start and stop them, or do other specific operations (@pxref{Jump
11897 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11903 The above command, run as @code{root}, lists the currently defined
11904 services. The @command{herd doc} command shows a synopsis of the given
11905 service and its associated actions:
11909 Run libc's name service cache daemon (nscd).
11911 # herd doc nscd action invalidate
11912 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11915 The @command{start}, @command{stop}, and @command{restart} sub-commands
11916 have the effect you would expect. For instance, the commands below stop
11917 the nscd service and restart the Xorg display server:
11921 Service nscd has been stopped.
11922 # herd restart xorg-server
11923 Service xorg-server has been stopped.
11924 Service xorg-server has been started.
11927 The following sections document the available services, starting with
11928 the core services, that may be used in an @code{operating-system}
11932 * Base Services:: Essential system services.
11933 * Scheduled Job Execution:: The mcron service.
11934 * Log Rotation:: The rottlog service.
11935 * Networking Services:: Network setup, SSH daemon, etc.
11936 * X Window:: Graphical display.
11937 * Printing Services:: Local and remote printer support.
11938 * Desktop Services:: D-Bus and desktop services.
11939 * Sound Services:: ALSA and Pulseaudio services.
11940 * Database Services:: SQL databases, key-value stores, etc.
11941 * Mail Services:: IMAP, POP3, SMTP, and all that.
11942 * Messaging Services:: Messaging services.
11943 * Telephony Services:: Telephony services.
11944 * Monitoring Services:: Monitoring services.
11945 * Kerberos Services:: Kerberos services.
11946 * LDAP Services:: LDAP services.
11947 * Web Services:: Web servers.
11948 * Certificate Services:: TLS certificates via Let's Encrypt.
11949 * DNS Services:: DNS daemons.
11950 * VPN Services:: VPN daemons.
11951 * Network File System:: NFS related services.
11952 * Continuous Integration:: The Cuirass service.
11953 * Power Management Services:: Extending battery life.
11954 * Audio Services:: The MPD.
11955 * Virtualization Services:: Virtualization services.
11956 * Version Control Services:: Providing remote access to Git repositories.
11957 * Game Services:: Game servers.
11958 * PAM Mount Service:: Service to mount volumes when logging in.
11959 * Guix Services:: Services relating specifically to Guix.
11960 * Miscellaneous Services:: Other services.
11963 @node Base Services
11964 @subsection Base Services
11966 The @code{(gnu services base)} module provides definitions for the basic
11967 services that one expects from the system. The services exported by
11968 this module are listed below.
11970 @defvr {Scheme Variable} %base-services
11971 This variable contains a list of basic services (@pxref{Service Types
11972 and Services}, for more information on service objects) one would
11973 expect from the system: a login service (mingetty) on each tty, syslogd,
11974 the libc name service cache daemon (nscd), the udev device manager, and
11977 This is the default value of the @code{services} field of
11978 @code{operating-system} declarations. Usually, when customizing a
11979 system, you will want to append services to @code{%base-services}, like
11983 (append (list (service avahi-service-type)
11984 (service openssh-service-type))
11989 @defvr {Scheme Variable} special-files-service-type
11990 This is the service that sets up ``special files'' such as
11991 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11993 The value associated with @code{special-files-service-type} services
11994 must be a list of tuples where the first element is the ``special file''
11995 and the second element is its target. By default it is:
11997 @cindex @file{/bin/sh}
11998 @cindex @file{sh}, in @file{/bin}
12000 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12003 @cindex @file{/usr/bin/env}
12004 @cindex @file{env}, in @file{/usr/bin}
12005 If you want to add, say, @code{/usr/bin/env} to your system, you can
12009 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12010 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12013 Since this is part of @code{%base-services}, you can use
12014 @code{modify-services} to customize the set of special files
12015 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12016 to add a special file is @i{via} the @code{extra-special-file} procedure
12020 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12021 Use @var{target} as the ``special file'' @var{file}.
12023 For example, adding the following lines to the @code{services} field of
12024 your operating system declaration leads to a @file{/usr/bin/env}
12028 (extra-special-file "/usr/bin/env"
12029 (file-append coreutils "/bin/env"))
12033 @deffn {Scheme Procedure} host-name-service @var{name}
12034 Return a service that sets the host name to @var{name}.
12037 @deffn {Scheme Procedure} login-service @var{config}
12038 Return a service to run login according to @var{config}, a
12039 @code{<login-configuration>} object, which specifies the message of the day,
12040 among other things.
12043 @deftp {Data Type} login-configuration
12044 This is the data type representing the configuration of login.
12049 @cindex message of the day
12050 A file-like object containing the ``message of the day''.
12052 @item @code{allow-empty-passwords?} (default: @code{#t})
12053 Allow empty passwords by default so that first-time users can log in when
12054 the 'root' account has just been created.
12059 @deffn {Scheme Procedure} mingetty-service @var{config}
12060 Return a service to run mingetty according to @var{config}, a
12061 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12065 @deftp {Data Type} mingetty-configuration
12066 This is the data type representing the configuration of Mingetty, which
12067 provides the default implementation of virtual console log-in.
12072 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12074 @item @code{auto-login} (default: @code{#f})
12075 When true, this field must be a string denoting the user name under
12076 which the system automatically logs in. When it is @code{#f}, a
12077 user name and password must be entered to log in.
12079 @item @code{login-program} (default: @code{#f})
12080 This must be either @code{#f}, in which case the default log-in program
12081 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12082 the name of the log-in program.
12084 @item @code{login-pause?} (default: @code{#f})
12085 When set to @code{#t} in conjunction with @var{auto-login}, the user
12086 will have to press a key before the log-in shell is launched.
12088 @item @code{mingetty} (default: @var{mingetty})
12089 The Mingetty package to use.
12094 @deffn {Scheme Procedure} agetty-service @var{config}
12095 Return a service to run agetty according to @var{config}, an
12096 @code{<agetty-configuration>} object, which specifies the tty to run,
12097 among other things.
12100 @deftp {Data Type} agetty-configuration
12101 This is the data type representing the configuration of agetty, which
12102 implements virtual and serial console log-in. See the @code{agetty(8)}
12103 man page for more information.
12108 The name of the console this agetty runs on, as a string---e.g.,
12109 @code{"ttyS0"}. This argument is optional, it will default to
12110 a reasonable default serial port used by the kernel Linux.
12112 For this, if there is a value for an option @code{agetty.tty} in the kernel
12113 command line, agetty will extract the device name of the serial port
12114 from it and use that.
12116 If not and if there is a value for an option @code{console} with a tty in
12117 the Linux command line, agetty will extract the device name of the
12118 serial port from it and use that.
12120 In both cases, agetty will leave the other serial device settings
12121 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12124 @item @code{baud-rate} (default: @code{#f})
12125 A string containing a comma-separated list of one or more baud rates, in
12128 @item @code{term} (default: @code{#f})
12129 A string containing the value used for the @code{TERM} environment
12132 @item @code{eight-bits?} (default: @code{#f})
12133 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12136 @item @code{auto-login} (default: @code{#f})
12137 When passed a login name, as a string, the specified user will be logged
12138 in automatically without prompting for their login name or password.
12140 @item @code{no-reset?} (default: @code{#f})
12141 When @code{#t}, don't reset terminal cflags (control modes).
12143 @item @code{host} (default: @code{#f})
12144 This accepts a string containing the "login_host", which will be written
12145 into the @file{/var/run/utmpx} file.
12147 @item @code{remote?} (default: @code{#f})
12148 When set to @code{#t} in conjunction with @var{host}, this will add an
12149 @code{-r} fakehost option to the command line of the login program
12150 specified in @var{login-program}.
12152 @item @code{flow-control?} (default: @code{#f})
12153 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12155 @item @code{no-issue?} (default: @code{#f})
12156 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12157 not be displayed before presenting the login prompt.
12159 @item @code{init-string} (default: @code{#f})
12160 This accepts a string that will be sent to the tty or modem before
12161 sending anything else. It can be used to initialize a modem.
12163 @item @code{no-clear?} (default: @code{#f})
12164 When set to @code{#t}, agetty will not clear the screen before showing
12167 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12168 This must be either a gexp denoting the name of a log-in program, or
12169 unset, in which case the default value is the @command{login} from the
12172 @item @code{local-line} (default: @code{#f})
12173 Control the CLOCAL line flag. This accepts one of three symbols as
12174 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12175 the default value chosen by agetty is @code{'auto}.
12177 @item @code{extract-baud?} (default: @code{#f})
12178 When set to @code{#t}, instruct agetty to try to extract the baud rate
12179 from the status messages produced by certain types of modems.
12181 @item @code{skip-login?} (default: @code{#f})
12182 When set to @code{#t}, do not prompt the user for a login name. This
12183 can be used with @var{login-program} field to use non-standard login
12186 @item @code{no-newline?} (default: @code{#f})
12187 When set to @code{#t}, do not print a newline before printing the
12188 @file{/etc/issue} file.
12190 @c Is this dangerous only when used with login-program, or always?
12191 @item @code{login-options} (default: @code{#f})
12192 This option accepts a string containing options that are passed to the
12193 login program. When used with the @var{login-program}, be aware that a
12194 malicious user could try to enter a login name containing embedded
12195 options that could be parsed by the login program.
12197 @item @code{login-pause} (default: @code{#f})
12198 When set to @code{#t}, wait for any key before showing the login prompt.
12199 This can be used in conjunction with @var{auto-login} to save memory by
12200 lazily spawning shells.
12202 @item @code{chroot} (default: @code{#f})
12203 Change root to the specified directory. This option accepts a directory
12206 @item @code{hangup?} (default: @code{#f})
12207 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12208 specified terminal.
12210 @item @code{keep-baud?} (default: @code{#f})
12211 When set to @code{#t}, try to keep the existing baud rate. The baud
12212 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12215 @item @code{timeout} (default: @code{#f})
12216 When set to an integer value, terminate if no user name could be read
12217 within @var{timeout} seconds.
12219 @item @code{detect-case?} (default: @code{#f})
12220 When set to @code{#t}, turn on support for detecting an uppercase-only
12221 terminal. This setting will detect a login name containing only
12222 uppercase letters as indicating an uppercase-only terminal and turn on
12223 some upper-to-lower case conversions. Note that this will not support
12224 Unicode characters.
12226 @item @code{wait-cr?} (default: @code{#f})
12227 When set to @code{#t}, wait for the user or modem to send a
12228 carriage-return or linefeed character before displaying
12229 @file{/etc/issue} or login prompt. This is typically used with the
12230 @var{init-string} option.
12232 @item @code{no-hints?} (default: @code{#f})
12233 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12236 @item @code{no-hostname?} (default: @code{#f})
12237 By default, the hostname is printed. When this option is set to
12238 @code{#t}, no hostname will be shown at all.
12240 @item @code{long-hostname?} (default: @code{#f})
12241 By default, the hostname is only printed until the first dot. When this
12242 option is set to @code{#t}, the fully qualified hostname by
12243 @code{gethostname} or @code{getaddrinfo} is shown.
12245 @item @code{erase-characters} (default: @code{#f})
12246 This option accepts a string of additional characters that should be
12247 interpreted as backspace when the user types their login name.
12249 @item @code{kill-characters} (default: @code{#f})
12250 This option accepts a string that should be interpreted to mean "ignore
12251 all previous characters" (also called a "kill" character) when the user
12252 types their login name.
12254 @item @code{chdir} (default: @code{#f})
12255 This option accepts, as a string, a directory path that will be changed
12258 @item @code{delay} (default: @code{#f})
12259 This options accepts, as an integer, the number of seconds to sleep
12260 before opening the tty and displaying the login prompt.
12262 @item @code{nice} (default: @code{#f})
12263 This option accepts, as an integer, the nice value with which to run the
12264 @command{login} program.
12266 @item @code{extra-options} (default: @code{'()})
12267 This option provides an "escape hatch" for the user to provide arbitrary
12268 command-line arguments to @command{agetty} as a list of strings.
12273 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12274 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12275 according to @var{config}, a @code{<kmscon-configuration>} object, which
12276 specifies the tty to run, among other things.
12279 @deftp {Data Type} kmscon-configuration
12280 This is the data type representing the configuration of Kmscon, which
12281 implements virtual console log-in.
12285 @item @code{virtual-terminal}
12286 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12288 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12289 A gexp denoting the name of the log-in program. The default log-in program is
12290 @command{login} from the Shadow tool suite.
12292 @item @code{login-arguments} (default: @code{'("-p")})
12293 A list of arguments to pass to @command{login}.
12295 @item @code{auto-login} (default: @code{#f})
12296 When passed a login name, as a string, the specified user will be logged
12297 in automatically without prompting for their login name or password.
12299 @item @code{hardware-acceleration?} (default: #f)
12300 Whether to use hardware acceleration.
12302 @item @code{kmscon} (default: @var{kmscon})
12303 The Kmscon package to use.
12308 @cindex name service cache daemon
12310 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12311 [#:name-services '()]
12312 Return a service that runs the libc name service cache daemon (nscd) with the
12313 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12314 Service Switch}, for an example.
12316 For convenience, the Shepherd service for nscd provides the following actions:
12320 @cindex cache invalidation, nscd
12321 @cindex nscd, cache invalidation
12322 This invalidate the given cache. For instance, running:
12325 herd invalidate nscd hosts
12329 invalidates the host name lookup cache of nscd.
12332 Running @command{herd statistics nscd} displays information about nscd usage
12338 @defvr {Scheme Variable} %nscd-default-configuration
12339 This is the default @code{<nscd-configuration>} value (see below) used
12340 by @code{nscd-service}. It uses the caches defined by
12341 @var{%nscd-default-caches}; see below.
12344 @deftp {Data Type} nscd-configuration
12345 This is the data type representing the name service cache daemon (nscd)
12350 @item @code{name-services} (default: @code{'()})
12351 List of packages denoting @dfn{name services} that must be visible to
12352 the nscd---e.g., @code{(list @var{nss-mdns})}.
12354 @item @code{glibc} (default: @var{glibc})
12355 Package object denoting the GNU C Library providing the @command{nscd}
12358 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12359 Name of the nscd log file. This is where debugging output goes when
12360 @code{debug-level} is strictly positive.
12362 @item @code{debug-level} (default: @code{0})
12363 Integer denoting the debugging levels. Higher numbers mean that more
12364 debugging output is logged.
12366 @item @code{caches} (default: @var{%nscd-default-caches})
12367 List of @code{<nscd-cache>} objects denoting things to be cached; see
12373 @deftp {Data Type} nscd-cache
12374 Data type representing a cache database of nscd and its parameters.
12378 @item @code{database}
12379 This is a symbol representing the name of the database to be cached.
12380 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12381 @code{services}, which designate the corresponding NSS database
12382 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12384 @item @code{positive-time-to-live}
12385 @itemx @code{negative-time-to-live} (default: @code{20})
12386 A number representing the number of seconds during which a positive or
12387 negative lookup result remains in cache.
12389 @item @code{check-files?} (default: @code{#t})
12390 Whether to check for updates of the files corresponding to
12393 For instance, when @var{database} is @code{hosts}, setting this flag
12394 instructs nscd to check for updates in @file{/etc/hosts} and to take
12397 @item @code{persistent?} (default: @code{#t})
12398 Whether the cache should be stored persistently on disk.
12400 @item @code{shared?} (default: @code{#t})
12401 Whether the cache should be shared among users.
12403 @item @code{max-database-size} (default: 32@tie{}MiB)
12404 Maximum size in bytes of the database cache.
12406 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12407 @c settings, so leave them out.
12412 @defvr {Scheme Variable} %nscd-default-caches
12413 List of @code{<nscd-cache>} objects used by default by
12414 @code{nscd-configuration} (see above).
12416 It enables persistent and aggressive caching of service and host name
12417 lookups. The latter provides better host name lookup performance,
12418 resilience in the face of unreliable name servers, and also better
12419 privacy---often the result of host name lookups is in local cache, so
12420 external name servers do not even need to be queried.
12423 @anchor{syslog-configuration-type}
12426 @deftp {Data Type} syslog-configuration
12427 This data type represents the configuration of the syslog daemon.
12430 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12431 The syslog daemon to use.
12433 @item @code{config-file} (default: @code{%default-syslog.conf})
12434 The syslog configuration file to use.
12439 @anchor{syslog-service}
12441 @deffn {Scheme Procedure} syslog-service @var{config}
12442 Return a service that runs a syslog daemon according to @var{config}.
12444 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12445 information on the configuration file syntax.
12448 @defvr {Scheme Variable} guix-service-type
12449 This is the type of the service that runs the build daemon,
12450 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12451 @code{guix-configuration} record as described below.
12454 @anchor{guix-configuration-type}
12455 @deftp {Data Type} guix-configuration
12456 This data type represents the configuration of the Guix build daemon.
12457 @xref{Invoking guix-daemon}, for more information.
12460 @item @code{guix} (default: @var{guix})
12461 The Guix package to use.
12463 @item @code{build-group} (default: @code{"guixbuild"})
12464 Name of the group for build user accounts.
12466 @item @code{build-accounts} (default: @code{10})
12467 Number of build user accounts to create.
12469 @item @code{authorize-key?} (default: @code{#t})
12470 @cindex substitutes, authorization thereof
12471 Whether to authorize the substitute keys listed in
12472 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12473 (@pxref{Substitutes}).
12475 @vindex %default-authorized-guix-keys
12476 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12477 The list of authorized key files for archive imports, as a list of
12478 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12479 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12481 @item @code{use-substitutes?} (default: @code{#t})
12482 Whether to use substitutes.
12484 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12485 The list of URLs where to look for substitutes by default.
12487 @item @code{max-silent-time} (default: @code{0})
12488 @itemx @code{timeout} (default: @code{0})
12489 The number of seconds of silence and the number of seconds of activity,
12490 respectively, after which a build process times out. A value of zero
12491 disables the timeout.
12493 @item @code{log-compression} (default: @code{'bzip2})
12494 The type of compression used for build logs---one of @code{gzip},
12495 @code{bzip2}, or @code{none}.
12497 @item @code{extra-options} (default: @code{'()})
12498 List of extra command-line options for @command{guix-daemon}.
12500 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12501 File where @command{guix-daemon}'s standard output and standard error
12504 @item @code{http-proxy} (default: @code{#f})
12505 The HTTP proxy used for downloading fixed-output derivations and
12508 @item @code{tmpdir} (default: @code{#f})
12509 A directory path where the @command{guix-daemon} will perform builds.
12514 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12515 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12516 udev rules can be provided as a list of files through the @var{rules}
12517 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12518 @code{(gnu services base)} simplify the creation of such rule files.
12521 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12522 Return a udev-rule file named @var{file-name} containing the rules
12523 defined by the @var{contents} literal.
12525 In the following example, a rule for a USB device is defined to be
12526 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12527 upon detecting a USB device with a given product identifier.
12530 (define %example-udev-rule
12532 "90-usb-thing.rules"
12533 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12534 "ATTR@{product@}==\"Example\", "
12535 "RUN+=\"/path/to/script\"")))
12538 The @command{herd rules udev} command, as root, returns the name of the
12539 directory containing all the active udev rules.
12542 Here we show how the default @var{udev-service} can be extended with it.
12548 (modify-services %desktop-services
12549 (udev-service-type config =>
12550 (udev-configuration (inherit config)
12551 (rules (append (udev-configuration-rules config)
12552 (list %example-udev-rule))))))))
12555 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12556 Return a udev file named @var{file-name} containing the rules defined
12557 within @var{file}, a file-like object.
12559 The following example showcases how we can use an existing rule file.
12562 (use-modules (guix download) ;for url-fetch
12563 (guix packages) ;for origin
12566 (define %android-udev-rules
12568 "51-android-udev.rules"
12569 (let ((version "20170910"))
12572 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12573 "android-udev-rules/" version "/51-android.rules"))
12575 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12579 Additionally, Guix package definitions can be included in @var{rules} in
12580 order to extend the udev rules with the definitions found under their
12581 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12582 @var{file->udev-rule} example, we could have used the
12583 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12584 packages android)} module.
12586 The following example shows how to use the @var{android-udev-rules}
12587 package so that the Android tool @command{adb} can detect devices
12588 without root privileges. It also details how to create the
12589 @code{adbusers} group, which is required for the proper functioning of
12590 the rules defined within the @var{android-udev-rules} package. To
12591 create such a group, we must define it both as part of the
12592 @var{supplementary-groups} of our @var{user-account} declaration, as
12593 well as in the @var{groups} field of the @var{operating-system} record.
12596 (use-modules (gnu packages android) ;for android-udev-rules
12597 (gnu system shadow) ;for user-group
12602 (users (cons (user-acount
12604 (supplementary-groups
12605 '("adbusers" ;for adb
12606 "wheel" "netdev" "audio" "video")))))
12608 (groups (cons (user-group (system? #t) (name "adbusers"))
12614 (modify-services %desktop-services
12617 (udev-configuration (inherit config)
12618 (rules (cons android-udev-rules
12619 (udev-configuration-rules config))))))))
12622 @defvr {Scheme Variable} urandom-seed-service-type
12623 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12624 when rebooting. It also tries to seed @file{/dev/urandom} from
12625 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12629 @defvr {Scheme Variable} %random-seed-file
12630 This is the name of the file where some random bytes are saved by
12631 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12632 It defaults to @file{/var/lib/random-seed}.
12637 @defvr {Scheme Variable} gpm-service-type
12638 This is the type of the service that runs GPM, the @dfn{general-purpose
12639 mouse daemon}, which provides mouse support to the Linux console. GPM
12640 allows users to use the mouse in the console, notably to select, copy,
12643 The value for services of this type must be a @code{gpm-configuration}
12644 (see below). This service is not part of @code{%base-services}.
12647 @deftp {Data Type} gpm-configuration
12648 Data type representing the configuration of GPM.
12651 @item @code{options} (default: @code{%default-gpm-options})
12652 Command-line options passed to @command{gpm}. The default set of
12653 options instruct @command{gpm} to listen to mouse events on
12654 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12657 @item @code{gpm} (default: @code{gpm})
12658 The GPM package to use.
12663 @anchor{guix-publish-service-type}
12664 @deffn {Scheme Variable} guix-publish-service-type
12665 This is the service type for @command{guix publish} (@pxref{Invoking
12666 guix publish}). Its value must be a @code{guix-publish-configuration}
12667 object, as described below.
12669 This assumes that @file{/etc/guix} already contains a signing key pair as
12670 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12671 archive}). If that is not the case, the service will fail to start.
12674 @deftp {Data Type} guix-publish-configuration
12675 Data type representing the configuration of the @code{guix publish}
12679 @item @code{guix} (default: @code{guix})
12680 The Guix package to use.
12682 @item @code{port} (default: @code{80})
12683 The TCP port to listen for connections.
12685 @item @code{host} (default: @code{"localhost"})
12686 The host (and thus, network interface) to listen to. Use
12687 @code{"0.0.0.0"} to listen on all the network interfaces.
12689 @item @code{compression} (default: @code{'(("gzip" 3))})
12690 This is a list of compression method/level tuple used when compressing
12691 substitutes. For example, to compress all substitutes with @emph{both} lzip
12692 at level 7 and gzip at level 9, write:
12695 '(("lzip" 7) ("gzip" 9))
12698 Level 9 achieves the best compression ratio at the expense of increased CPU
12699 usage, whereas level 1 achieves fast compression.
12701 An empty list disables compression altogether.
12703 @item @code{nar-path} (default: @code{"nar"})
12704 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12705 publish, @code{--nar-path}}, for details.
12707 @item @code{cache} (default: @code{#f})
12708 When it is @code{#f}, disable caching and instead generate archives on
12709 demand. Otherwise, this should be the name of a directory---e.g.,
12710 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12711 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12712 @option{--cache}}, for more information on the tradeoffs involved.
12714 @item @code{workers} (default: @code{#f})
12715 When it is an integer, this is the number of worker threads used for
12716 caching; when @code{#f}, the number of processors is used.
12717 @xref{Invoking guix publish, @option{--workers}}, for more information.
12719 @item @code{ttl} (default: @code{#f})
12720 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12721 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12722 for more information.
12726 @anchor{rngd-service}
12727 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12728 [#:device "/dev/hwrng"]
12729 Return a service that runs the @command{rngd} program from @var{rng-tools}
12730 to add @var{device} to the kernel's entropy pool. The service will fail if
12731 @var{device} does not exist.
12734 @anchor{pam-limits-service}
12735 @cindex session limits
12740 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12742 Return a service that installs a configuration file for the
12743 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12744 @code{pam_limits} module}. The procedure optionally takes a list of
12745 @code{pam-limits-entry} values, which can be used to specify
12746 @code{ulimit} limits and nice priority limits to user sessions.
12748 The following limits definition sets two hard and soft limits for all
12749 login sessions of users in the @code{realtime} group:
12752 (pam-limits-service
12754 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12755 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12758 The first entry increases the maximum realtime priority for
12759 non-privileged processes; the second entry lifts any restriction of the
12760 maximum address space that can be locked in memory. These settings are
12761 commonly used for real-time audio systems.
12764 @node Scheduled Job Execution
12765 @subsection Scheduled Job Execution
12769 @cindex scheduling jobs
12770 The @code{(gnu services mcron)} module provides an interface to
12771 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12772 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12773 Unix @command{cron} daemon; the main difference is that it is
12774 implemented in Guile Scheme, which provides a lot of flexibility when
12775 specifying the scheduling of jobs and their actions.
12777 The example below defines an operating system that runs the
12778 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12779 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12780 well as the @command{mkid} command on behalf of an unprivileged user
12781 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12782 gexps to introduce job definitions that are passed to mcron
12783 (@pxref{G-Expressions}).
12786 (use-modules (guix) (gnu) (gnu services mcron))
12787 (use-package-modules base idutils)
12789 (define updatedb-job
12790 ;; Run 'updatedb' at 3AM every day. Here we write the
12791 ;; job's action as a Scheme procedure.
12792 #~(job '(next-hour '(3))
12794 (execl (string-append #$findutils "/bin/updatedb")
12796 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12798 (define garbage-collector-job
12799 ;; Collect garbage 5 minutes after midnight every day.
12800 ;; The job's action is a shell command.
12801 #~(job "5 0 * * *" ;Vixie cron syntax
12804 (define idutils-job
12805 ;; Update the index database as user "charlie" at 12:15PM
12806 ;; and 19:15PM. This runs from the user's home directory.
12807 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12808 (string-append #$idutils "/bin/mkid src")
12813 (services (cons (service mcron-service-type
12814 (mcron-configuration
12815 (jobs (list garbage-collector-job
12821 For more complex jobs defined in Scheme where you need control over the top
12822 level, for instance to introduce a @code{use-modules} form, you can move your
12823 code to a separate program using the @code{program-file} procedure of the
12824 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
12828 (define %battery-alert-job
12829 ;; Beep when the battery percentage falls below %MIN-LEVEL.
12831 '(next-minute (range 0 60 1))
12833 "battery-alert.scm"
12834 (with-imported-modules (source-module-closure
12835 '((guix build utils)))
12837 (define %min-level 20)
12838 (use-modules (guix build utils)
12841 (ice-9 textual-ports)
12843 (setenv "LC_ALL" "C") ;ensure English output
12844 (and-let* ((input-pipe (open-pipe*
12846 #$(file-append acpi "/bin/acpi")))
12847 (output (get-string-all input-pipe))
12848 (m (string-match "Discharging, ([0-9]+)%" output))
12849 (level (string->number (match:substring m 1)))
12850 ((< level %min-level)))
12851 (format #t "warning: Battery level is low (~a%)~%" level)
12852 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
12855 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12856 for more information on mcron job specifications. Below is the
12857 reference of the mcron service.
12859 On a running system, you can use the @code{schedule} action of the service to
12860 visualize the mcron jobs that will be executed next:
12863 # herd schedule mcron
12867 The example above lists the next five tasks that will be executed, but you can
12868 also specify the number of tasks to display:
12871 # herd schedule mcron 10
12874 @defvr {Scheme Variable} mcron-service-type
12875 This is the type of the @code{mcron} service, whose value is an
12876 @code{mcron-configuration} object.
12878 This service type can be the target of a service extension that provides
12879 it additional job specifications (@pxref{Service Composition}). In
12880 other words, it is possible to define services that provide additional
12884 @deftp {Data Type} mcron-configuration
12885 Data type representing the configuration of mcron.
12888 @item @code{mcron} (default: @var{mcron})
12889 The mcron package to use.
12892 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12893 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12894 specifications,, mcron, GNU@tie{}mcron}).
12900 @subsection Log Rotation
12903 @cindex log rotation
12905 Log files such as those found in @file{/var/log} tend to grow endlessly,
12906 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12907 their contents in separate files, possibly compressed. The @code{(gnu
12908 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12909 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12911 The example below defines an operating system that provides log rotation
12912 with the default settings, for commonly encountered log files.
12915 (use-modules (guix) (gnu))
12916 (use-service-modules admin mcron)
12917 (use-package-modules base idutils)
12921 (services (cons (service rottlog-service-type)
12925 @defvr {Scheme Variable} rottlog-service-type
12926 This is the type of the Rottlog service, whose value is a
12927 @code{rottlog-configuration} object.
12929 Other services can extend this one with new @code{log-rotation} objects
12930 (see below), thereby augmenting the set of files to be rotated.
12932 This service type can define mcron jobs (@pxref{Scheduled Job
12933 Execution}) to run the rottlog service.
12936 @deftp {Data Type} rottlog-configuration
12937 Data type representing the configuration of rottlog.
12940 @item @code{rottlog} (default: @code{rottlog})
12941 The Rottlog package to use.
12943 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12944 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12945 rottlog, GNU Rot[t]log Manual}).
12947 @item @code{rotations} (default: @code{%default-rotations})
12948 A list of @code{log-rotation} objects as defined below.
12951 This is a list of gexps where each gexp corresponds to an mcron job
12952 specification (@pxref{Scheduled Job Execution}).
12956 @deftp {Data Type} log-rotation
12957 Data type representing the rotation of a group of log files.
12959 Taking an example from the Rottlog manual (@pxref{Period Related File
12960 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12966 (files '("/var/log/apache/*"))
12967 (options '("storedir apache-archives"
12973 The list of fields is as follows:
12976 @item @code{frequency} (default: @code{'weekly})
12977 The log rotation frequency, a symbol.
12980 The list of files or file glob patterns to rotate.
12982 @item @code{options} (default: @code{'()})
12983 The list of rottlog options for this rotation (@pxref{Configuration
12984 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12986 @item @code{post-rotate} (default: @code{#f})
12987 Either @code{#f} or a gexp to execute once the rotation has completed.
12991 @defvr {Scheme Variable} %default-rotations
12992 Specifies weekly rotation of @var{%rotated-files} and of
12993 @file{/var/log/guix-daemon.log}.
12996 @defvr {Scheme Variable} %rotated-files
12997 The list of syslog-controlled files to be rotated. By default it is:
12998 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
12999 "/var/log/maillog")}.
13002 @node Networking Services
13003 @subsection Networking Services
13005 The @code{(gnu services networking)} module provides services to configure
13006 the network interface.
13008 @cindex DHCP, networking service
13009 @defvr {Scheme Variable} dhcp-client-service-type
13010 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13011 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13012 is the DHCP client package to use, @code{isc-dhcp} by default.
13015 @deffn {Scheme Procedure} dhcpd-service-type
13016 This type defines a service that runs a DHCP daemon. To create a
13017 service of this type, you must supply a @code{<dhcpd-configuration>}.
13021 (service dhcpd-service-type
13022 (dhcpd-configuration
13023 (config-file (local-file "my-dhcpd.conf"))
13024 (interfaces '("enp0s25"))))
13028 @deftp {Data Type} dhcpd-configuration
13030 @item @code{package} (default: @code{isc-dhcp})
13031 The package that provides the DHCP daemon. This package is expected to
13032 provide the daemon at @file{sbin/dhcpd} relative to its output
13033 directory. The default package is the
13034 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13035 @item @code{config-file} (default: @code{#f})
13036 The configuration file to use. This is required. It will be passed to
13037 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13038 object (@pxref{G-Expressions, file-like objects}). See @code{man
13039 dhcpd.conf} for details on the configuration file syntax.
13040 @item @code{version} (default: @code{"4"})
13041 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13042 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13043 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13045 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13046 The run directory to use. At service activation time, this directory
13047 will be created if it does not exist.
13048 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13049 The PID file to use. This corresponds to the @code{-pf} option of
13050 @code{dhcpd}. See @code{man dhcpd} for details.
13051 @item @code{interfaces} (default: @code{'()})
13052 The names of the network interfaces on which dhcpd should listen for
13053 broadcasts. If this list is not empty, then its elements (which must be
13054 strings) will be appended to the @code{dhcpd} invocation when starting
13055 the daemon. It may not be necessary to explicitly specify any
13056 interfaces here; see @code{man dhcpd} for details.
13060 @defvr {Scheme Variable} static-networking-service-type
13061 This is the type for statically-configured network interfaces.
13062 @c TODO Document <static-networking> data structures.
13065 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13066 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13067 [#:requirement @code{'(udev)}]
13068 Return a service that starts @var{interface} with address @var{ip}. If
13069 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13070 it must be a string specifying the default network gateway. @var{requirement}
13071 can be used to declare a dependency on another service before configuring the
13074 This procedure can be called several times, one for each network
13075 interface of interest. Behind the scenes what it does is extend
13076 @code{static-networking-service-type} with additional network interfaces
13082 (static-networking-service "eno1" "192.168.1.82"
13083 #:gateway "192.168.1.2"
13084 #:name-servers '("192.168.1.2"))
13091 @cindex network management
13092 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13093 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13094 management daemon that aims to simplify wired and wireless networking.
13096 This service adds the @var{wicd} package to the global profile, providing
13097 several commands to interact with the daemon and configure networking:
13098 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13099 and @command{wicd-curses} user interfaces.
13102 @cindex ModemManager
13104 @defvr {Scheme Variable} modem-manager-service-type
13105 This is the service type for the
13106 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13107 service. The value for this service type is a
13108 @code{modem-manager-configuration} record.
13110 This service is part of @code{%desktop-services} (@pxref{Desktop
13114 @deftp {Data Type} modem-manager-configuration
13115 Data type representing the configuration of ModemManager.
13118 @item @code{modem-manager} (default: @code{modem-manager})
13119 The ModemManager package to use.
13124 @cindex USB_ModeSwitch
13125 @cindex Modeswitching
13127 @defvr {Scheme Variable} usb-modeswitch-service-type
13128 This is the service type for the
13129 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13130 value for this service type is a @code{usb-modeswitch-configuration} record.
13132 When plugged in, some USB modems (and other USB devices) initially present
13133 themselves as a read-only storage medium and not as a modem. They need to be
13134 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13135 installs udev rules to automatically modeswitch these devices when they are
13138 This service is part of @code{%desktop-services} (@pxref{Desktop
13142 @deftp {Data Type} usb-modeswitch-configuration
13143 Data type representing the configuration of USB_ModeSwitch.
13146 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13147 The USB_ModeSwitch package providing the binaries for modeswitching.
13149 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13150 The package providing the device data and udev rules file used by
13153 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13154 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13155 config file shipped with USB_ModeSwitch is used which disables logging to
13156 @file{/var/log} among other default settings. If set to @code{#f}, no config
13162 @cindex NetworkManager
13164 @defvr {Scheme Variable} network-manager-service-type
13165 This is the service type for the
13166 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13167 service. The value for this service type is a
13168 @code{network-manager-configuration} record.
13170 This service is part of @code{%desktop-services} (@pxref{Desktop
13174 @deftp {Data Type} network-manager-configuration
13175 Data type representing the configuration of NetworkManager.
13178 @item @code{network-manager} (default: @code{network-manager})
13179 The NetworkManager package to use.
13181 @item @code{dns} (default: @code{"default"})
13182 Processing mode for DNS, which affects how NetworkManager uses the
13183 @code{resolv.conf} configuration file.
13187 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13188 provided by currently active connections.
13191 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13192 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13193 then update @code{resolv.conf} to point to the local nameserver.
13195 With this setting, you can share your network connection. For example when
13196 you want to share your network connection to another laptop @i{via} an
13197 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13198 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13199 and reestablish the connection (or reboot).
13201 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13202 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13203 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13204 browser on your host system, or connect to the VM @i{via} SSH
13205 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13206 host-to-guest connection, run this command once:
13209 nmcli connection add type tun \
13210 connection.interface-name tap0 \
13211 tun.mode tap tun.owner $(id -u) \
13212 ipv4.method shared \
13213 ipv4.addresses 172.28.112.1/24
13216 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13217 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13218 @command{qemu-system-...}.
13221 NetworkManager will not modify @code{resolv.conf}.
13224 @item @code{vpn-plugins} (default: @code{'()})
13225 This is the list of available plugins for virtual private networks
13226 (VPNs). An example of this is the @code{network-manager-openvpn}
13227 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13233 @deffn {Scheme Variable} connman-service-type
13234 This is the service type to run @url{https://01.org/connman,Connman},
13235 a network connection manager.
13237 Its value must be an
13238 @code{connman-configuration} record as in this example:
13241 (service connman-service-type
13242 (connman-configuration
13243 (disable-vpn? #t)))
13246 See below for details about @code{connman-configuration}.
13249 @deftp {Data Type} connman-configuration
13250 Data Type representing the configuration of connman.
13253 @item @code{connman} (default: @var{connman})
13254 The connman package to use.
13256 @item @code{disable-vpn?} (default: @code{#f})
13257 When true, disable connman's vpn plugin.
13261 @cindex WPA Supplicant
13262 @defvr {Scheme Variable} wpa-supplicant-service-type
13263 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13264 supplicant}, an authentication daemon required to authenticate against
13265 encrypted WiFi or ethernet networks.
13268 @deftp {Data Type} wpa-supplicant-configuration
13269 Data type representing the configuration of WPA Supplicant.
13271 It takes the following parameters:
13274 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13275 The WPA Supplicant package to use.
13277 @item @code{dbus?} (default: @code{#t})
13278 Whether to listen for requests on D-Bus.
13280 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13281 Where to store the PID file.
13283 @item @code{interface} (default: @code{#f})
13284 If this is set, it must specify the name of a network interface that
13285 WPA supplicant will control.
13287 @item @code{config-file} (default: @code{#f})
13288 Optional configuration file to use.
13290 @item @code{extra-options} (default: @code{'()})
13291 List of additional command-line arguments to pass to the daemon.
13296 @defvr {Scheme Variable} iptables-service-type
13297 This is the service type to set up an iptables configuration. iptables is a
13298 packet filtering framework supported by the Linux kernel. This service
13299 supports configuring iptables for both IPv4 and IPv6. A simple example
13300 configuration rejecting all incoming connections except those to the ssh port
13304 (service iptables-service-type
13305 (iptables-configuration
13306 (ipv4-rules (plain-file "iptables.rules" "*filter
13310 -A INPUT -p tcp --dport 22 -j ACCEPT
13311 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13314 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13318 -A INPUT -p tcp --dport 22 -j ACCEPT
13319 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13325 @deftp {Data Type} iptables-configuration
13326 The data type representing the configuration of iptables.
13329 @item @code{iptables} (default: @code{iptables})
13330 The iptables package that provides @code{iptables-restore} and
13331 @code{ip6tables-restore}.
13332 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13333 The iptables rules to use. It will be passed to @code{iptables-restore}.
13334 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13336 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13337 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13338 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13344 @defvr {Scheme Variable} nftables-service-type
13345 This is the service type to set up a nftables configuration. nftables is a
13346 netfilter project that aims to replace the existing iptables, ip6tables,
13347 arptables and ebtables framework. It provides a new packet filtering
13348 framework, a new user-space utility @command{nft}, and a compatibility layer
13349 for iptables. This service comes with a default ruleset
13350 @code{%default-nftables-ruleset} that rejecting all incomming connections
13351 except those to the ssh port 22. To use it, simply write:
13354 (service nftables-service-type)
13358 @deftp {Data Type} nftables-configuration
13359 The data type representing the configuration of nftables.
13362 @item @code{package} (default: @code{nftables})
13363 The nftables package that provides @command{nft}.
13364 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13365 The nftables ruleset to use. This may be any ``file-like'' object
13366 (@pxref{G-Expressions, file-like objects}).
13370 @cindex NTP (Network Time Protocol), service
13371 @cindex ntpd, service for the Network Time Protocol daemon
13372 @cindex real time clock
13373 @defvr {Scheme Variable} ntp-service-type
13374 This is the type of the service running the @uref{http://www.ntp.org,
13375 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13376 system clock synchronized with that of the specified NTP servers.
13378 The value of this service is an @code{ntpd-configuration} object, as described
13382 @deftp {Data Type} ntp-configuration
13383 This is the data type for the NTP service configuration.
13386 @item @code{servers} (default: @code{%ntp-servers})
13387 This is the list of servers (@code{<ntp-server>} records) with which
13388 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13391 @item @code{allow-large-adjustment?} (default: @code{#t})
13392 This determines whether @command{ntpd} is allowed to make an initial
13393 adjustment of more than 1,000 seconds.
13395 @item @code{ntp} (default: @code{ntp})
13396 The NTP package to use.
13400 @defvr {Scheme Variable} %ntp-servers
13401 List of host names used as the default NTP servers. These are servers of the
13402 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13405 @deftp {Data Type} ntp-server
13406 The data type representing the configuration of a NTP server.
13409 @item @code{type} (default: @code{'server})
13410 The type of the NTP server, given as a symbol. One of @code{'pool},
13411 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13413 @item @code{address}
13414 The address of the server, as a string.
13416 @item @code{options}
13417 NTPD options to use with that specific server, given as a list of option names
13418 and/or of option names and values tuples. The following example define a server
13419 to use with the options @option{iburst} and @option{prefer}, as well as
13420 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13425 (address "some.ntp.server.org")
13426 (options `(iburst (version 3) (maxpoll 16) prefer))))
13432 @deffn {Scheme Procedure} openntpd-service-type
13433 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13434 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13435 clock synchronized with that of the given servers.
13439 openntpd-service-type
13440 (openntpd-configuration
13441 (listen-on '("127.0.0.1" "::1"))
13442 (sensor '("udcf0 correction 70000"))
13443 (constraint-from '("www.gnu.org"))
13444 (constraints-from '("https://www.google.com/"))
13445 (allow-large-adjustment? #t)))
13450 @defvr {Scheme Variable} %openntpd-servers
13451 This variable is a list of the server addresses defined in
13452 @var{%ntp-servers}.
13455 @deftp {Data Type} openntpd-configuration
13457 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13458 The openntpd executable to use.
13459 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13460 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13461 @item @code{query-from} (default: @code{'()})
13462 A list of local IP address the ntpd daemon should use for outgoing queries.
13463 @item @code{sensor} (default: @code{'()})
13464 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13465 will listen to each sensor that actually exists and ignore non-existent ones.
13466 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13468 @item @code{server} (default: @code{'()})
13469 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13470 @item @code{servers} (default: @var{%openntp-servers})
13471 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13472 @item @code{constraint-from} (default: @code{'()})
13473 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13474 This time information is not used for precision but acts as an authenticated
13475 constraint, thereby reducing the impact of unauthenticated NTP
13476 man-in-the-middle attacks.
13477 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13479 @item @code{constraints-from} (default: @code{'()})
13480 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13481 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13482 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13483 @item @code{allow-large-adjustment?} (default: @code{#f})
13484 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13490 @deffn {Scheme variable} inetd-service-type
13491 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13492 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13493 connections on internet sockets, and lazily starts the specified server
13494 program when a connection is made on one of these sockets.
13496 The value of this service is an @code{inetd-configuration} object. The
13497 following example configures the @command{inetd} daemon to provide the
13498 built-in @command{echo} service, as well as an smtp service which
13499 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13500 gateway @code{hostname}:
13505 (inetd-configuration
13509 (socket-type 'stream)
13516 (socket-type 'stream)
13520 (program (file-append openssh "/bin/ssh"))
13522 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13523 "-W" "smtp-server:25" "user@@hostname")))))))
13526 See below for more details about @code{inetd-configuration}.
13529 @deftp {Data Type} inetd-configuration
13530 Data type representing the configuration of @command{inetd}.
13533 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13534 The @command{inetd} executable to use.
13536 @item @code{entries} (default: @code{'()})
13537 A list of @command{inetd} service entries. Each entry should be created
13538 by the @code{inetd-entry} constructor.
13542 @deftp {Data Type} inetd-entry
13543 Data type representing an entry in the @command{inetd} configuration.
13544 Each entry corresponds to a socket where @command{inetd} will listen for
13548 @item @code{node} (default: @code{#f})
13549 Optional string, a comma-separated list of local addresses
13550 @command{inetd} should use when listening for this service.
13551 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13552 description of all options.
13554 A string, the name must correspond to an entry in @code{/etc/services}.
13555 @item @code{socket-type}
13556 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13558 @item @code{protocol}
13559 A string, must correspond to an entry in @code{/etc/protocols}.
13560 @item @code{wait?} (default: @code{#t})
13561 Whether @command{inetd} should wait for the server to exit before
13562 listening to new service requests.
13564 A string containing the user (and, optionally, group) name of the user
13565 as whom the server should run. The group name can be specified in a
13566 suffix, separated by a colon or period, i.e.@: @code{"user"},
13567 @code{"user:group"} or @code{"user.group"}.
13568 @item @code{program} (default: @code{"internal"})
13569 The server program which will serve the requests, or @code{"internal"}
13570 if @command{inetd} should use a built-in service.
13571 @item @code{arguments} (default: @code{'()})
13572 A list strings or file-like objects, which are the server program's
13573 arguments, starting with the zeroth argument, i.e.@: the name of the
13574 program itself. For @command{inetd}'s internal services, this entry
13575 must be @code{'()} or @code{'("internal")}.
13578 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13579 detailed discussion of each configuration field.
13583 @defvr {Scheme Variable} tor-service-type
13584 This is the type for a service that runs the @uref{https://torproject.org,
13585 Tor} anonymous networking daemon. The service is configured using a
13586 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13587 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13591 @deftp {Data Type} tor-configuration
13593 @item @code{tor} (default: @code{tor})
13594 The package that provides the Tor daemon. This package is expected to provide
13595 the daemon at @file{bin/tor} relative to its output directory. The default
13596 package is the @uref{https://www.torproject.org, Tor Project's}
13599 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13600 The configuration file to use. It will be appended to a default configuration
13601 file, and the final configuration file will be passed to @code{tor} via its
13602 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13603 file-like objects}). See @code{man tor} for details on the configuration file
13606 @item @code{hidden-services} (default: @code{'()})
13607 The list of @code{<hidden-service>} records to use. For any hidden service
13608 you include in this list, appropriate configuration to enable the hidden
13609 service will be automatically added to the default configuration file. You
13610 may conveniently create @code{<hidden-service>} records using the
13611 @code{tor-hidden-service} procedure described below.
13613 @item @code{socks-socket-type} (default: @code{'tcp})
13614 The default socket type that Tor should use for its SOCKS socket. This must
13615 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13616 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13617 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13618 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13621 If you want to customize the SOCKS socket in more detail, leave
13622 @code{socks-socket-type} at its default value of @code{'tcp} and use
13623 @code{config-file} to override the default by providing your own
13624 @code{SocksPort} option.
13628 @cindex hidden service
13629 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13630 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13631 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13634 '((22 "127.0.0.1:22")
13635 (80 "127.0.0.1:8080"))
13638 In this example, port 22 of the hidden service is mapped to local port 22, and
13639 port 80 is mapped to local port 8080.
13641 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13642 the @file{hostname} file contains the @code{.onion} host name for the hidden
13645 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13646 project's documentation} for more information.
13649 The @code{(gnu services rsync)} module provides the following services:
13651 You might want an rsync daemon if you have files that you want available
13652 so anyone (or just yourself) can download existing files or upload new
13655 @deffn {Scheme Variable} rsync-service-type
13656 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13657 The value for this service type is a
13658 @command{rsync-configuration} record as in this example:
13661 (service rsync-service-type)
13664 See below for details about @code{rsync-configuration}.
13667 @deftp {Data Type} rsync-configuration
13668 Data type representing the configuration for @code{rsync-service}.
13671 @item @code{package} (default: @var{rsync})
13672 @code{rsync} package to use.
13674 @item @code{port-number} (default: @code{873})
13675 TCP port on which @command{rsync} listens for incoming connections. If port
13676 is less than @code{1024} @command{rsync} needs to be started as the
13677 @code{root} user and group.
13679 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13680 Name of the file where @command{rsync} writes its PID.
13682 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13683 Name of the file where @command{rsync} writes its lock file.
13685 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13686 Name of the file where @command{rsync} writes its log file.
13688 @item @code{use-chroot?} (default: @var{#t})
13689 Whether to use chroot for @command{rsync} shared directory.
13691 @item @code{share-path} (default: @file{/srv/rsync})
13692 Location of the @command{rsync} shared directory.
13694 @item @code{share-comment} (default: @code{"Rsync share"})
13695 Comment of the @command{rsync} shared directory.
13697 @item @code{read-only?} (default: @var{#f})
13698 Read-write permissions to shared directory.
13700 @item @code{timeout} (default: @code{300})
13701 I/O timeout in seconds.
13703 @item @code{user} (default: @var{"root"})
13704 Owner of the @code{rsync} process.
13706 @item @code{group} (default: @var{"root"})
13707 Group of the @code{rsync} process.
13709 @item @code{uid} (default: @var{"rsyncd"})
13710 User name or user ID that file transfers to and from that module should take
13711 place as when the daemon was run as @code{root}.
13713 @item @code{gid} (default: @var{"rsyncd"})
13714 Group name or group ID that will be used when accessing the module.
13719 Furthermore, @code{(gnu services ssh)} provides the following services.
13723 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13724 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13725 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13726 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13727 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13728 [#:public-key-authentication? #t] [#:initialize? #t]
13729 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13730 @var{host-key} must designate a file containing the host key, and readable
13733 When @var{daemonic?} is true, @command{lshd} will detach from the
13734 controlling terminal and log its output to syslogd, unless one sets
13735 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13736 depend on existence of syslogd service. When @var{pid-file?} is true,
13737 @command{lshd} writes its PID to the file called @var{pid-file}.
13739 When @var{initialize?} is true, automatically create the seed and host key
13740 upon service activation if they do not exist yet. This may take long and
13741 require interaction.
13743 When @var{initialize?} is false, it is up to the user to initialize the
13744 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13745 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13746 basics,,, lsh, LSH Manual}).
13748 When @var{interfaces} is empty, lshd listens for connections on all the
13749 network interfaces; otherwise, @var{interfaces} must be a list of host names
13752 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13753 passwords, and @var{root-login?} specifies whether to accept log-ins as
13756 The other options should be self-descriptive.
13761 @deffn {Scheme Variable} openssh-service-type
13762 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13763 shell daemon, @command{sshd}. Its value must be an
13764 @code{openssh-configuration} record as in this example:
13767 (service openssh-service-type
13768 (openssh-configuration
13769 (x11-forwarding? #t)
13770 (permit-root-login 'without-password)
13772 `(("alice" ,(local-file "alice.pub"))
13773 ("bob" ,(local-file "bob.pub"))))))
13776 See below for details about @code{openssh-configuration}.
13778 This service can be extended with extra authorized keys, as in this
13782 (service-extension openssh-service-type
13783 (const `(("charlie"
13784 ,(local-file "charlie.pub")))))
13788 @deftp {Data Type} openssh-configuration
13789 This is the configuration record for OpenSSH's @command{sshd}.
13792 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13793 Name of the file where @command{sshd} writes its PID.
13795 @item @code{port-number} (default: @code{22})
13796 TCP port on which @command{sshd} listens for incoming connections.
13798 @item @code{permit-root-login} (default: @code{#f})
13799 This field determines whether and when to allow logins as root. If
13800 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13801 If it's the symbol @code{'without-password}, then root logins are
13802 permitted but not with password-based authentication.
13804 @item @code{allow-empty-passwords?} (default: @code{#f})
13805 When true, users with empty passwords may log in. When false, they may
13808 @item @code{password-authentication?} (default: @code{#t})
13809 When true, users may log in with their password. When false, they have
13810 other authentication methods.
13812 @item @code{public-key-authentication?} (default: @code{#t})
13813 When true, users may log in using public key authentication. When
13814 false, users have to use other authentication method.
13816 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13817 This is used only by protocol version 2.
13819 @item @code{x11-forwarding?} (default: @code{#f})
13820 When true, forwarding of X11 graphical client connections is
13821 enabled---in other words, @command{ssh} options @option{-X} and
13822 @option{-Y} will work.
13824 @item @code{allow-agent-forwarding?} (default: @code{#t})
13825 Whether to allow agent forwarding.
13827 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13828 Whether to allow TCP forwarding.
13830 @item @code{gateway-ports?} (default: @code{#f})
13831 Whether to allow gateway ports.
13833 @item @code{challenge-response-authentication?} (default: @code{#f})
13834 Specifies whether challenge response authentication is allowed (e.g.@: via
13837 @item @code{use-pam?} (default: @code{#t})
13838 Enables the Pluggable Authentication Module interface. If set to
13839 @code{#t}, this will enable PAM authentication using
13840 @code{challenge-response-authentication?} and
13841 @code{password-authentication?}, in addition to PAM account and session
13842 module processing for all authentication types.
13844 Because PAM challenge response authentication usually serves an
13845 equivalent role to password authentication, you should disable either
13846 @code{challenge-response-authentication?} or
13847 @code{password-authentication?}.
13849 @item @code{print-last-log?} (default: @code{#t})
13850 Specifies whether @command{sshd} should print the date and time of the
13851 last user login when a user logs in interactively.
13853 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13854 Configures external subsystems (e.g.@: file transfer daemon).
13856 This is a list of two-element lists, each of which containing the
13857 subsystem name and a command (with optional arguments) to execute upon
13860 The command @command{internal-sftp} implements an in-process SFTP
13861 server. Alternately, one can specify the @command{sftp-server} command:
13863 (service openssh-service-type
13864 (openssh-configuration
13866 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13869 @item @code{accepted-environment} (default: @code{'()})
13870 List of strings describing which environment variables may be exported.
13872 Each string gets on its own line. See the @code{AcceptEnv} option in
13873 @code{man sshd_config}.
13875 This example allows ssh-clients to export the @code{COLORTERM} variable.
13876 It is set by terminal emulators, which support colors. You can use it in
13877 your shell's ressource file to enable colors for the prompt and commands
13878 if this variable is set.
13881 (service openssh-service-type
13882 (openssh-configuration
13883 (accepted-environment '("COLORTERM"))))
13886 @item @code{authorized-keys} (default: @code{'()})
13887 @cindex authorized keys, SSH
13888 @cindex SSH authorized keys
13889 This is the list of authorized keys. Each element of the list is a user
13890 name followed by one or more file-like objects that represent SSH public
13894 (openssh-configuration
13896 `(("rekado" ,(local-file "rekado.pub"))
13897 ("chris" ,(local-file "chris.pub"))
13898 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13902 registers the specified public keys for user accounts @code{rekado},
13903 @code{chris}, and @code{root}.
13905 Additional authorized keys can be specified @i{via}
13906 @code{service-extension}.
13908 Note that this does @emph{not} interfere with the use of
13909 @file{~/.ssh/authorized_keys}.
13911 @item @code{log-level} (default: @code{'info})
13912 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13913 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13914 page for @file{sshd_config} for the full list of level names.
13916 @item @code{extra-content} (default: @code{""})
13917 This field can be used to append arbitrary text to the configuration file. It
13918 is especially useful for elaborate configurations that cannot be expressed
13919 otherwise. This configuration, for example, would generally disable root
13920 logins, but permit them from one specific IP address:
13923 (openssh-configuration
13925 Match Address 192.168.0.1
13926 PermitRootLogin yes"))
13932 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13933 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13934 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13937 For example, to specify a Dropbear service listening on port 1234, add
13938 this call to the operating system's @code{services} field:
13941 (dropbear-service (dropbear-configuration
13942 (port-number 1234)))
13946 @deftp {Data Type} dropbear-configuration
13947 This data type represents the configuration of a Dropbear SSH daemon.
13950 @item @code{dropbear} (default: @var{dropbear})
13951 The Dropbear package to use.
13953 @item @code{port-number} (default: 22)
13954 The TCP port where the daemon waits for incoming connections.
13956 @item @code{syslog-output?} (default: @code{#t})
13957 Whether to enable syslog output.
13959 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13960 File name of the daemon's PID file.
13962 @item @code{root-login?} (default: @code{#f})
13963 Whether to allow @code{root} logins.
13965 @item @code{allow-empty-passwords?} (default: @code{#f})
13966 Whether to allow empty passwords.
13968 @item @code{password-authentication?} (default: @code{#t})
13969 Whether to enable password-based authentication.
13973 @defvr {Scheme Variable} %facebook-host-aliases
13974 This variable contains a string for use in @file{/etc/hosts}
13975 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13976 line contains a entry that maps a known server name of the Facebook
13977 on-line service---e.g., @code{www.facebook.com}---to the local
13978 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13980 This variable is typically used in the @code{hosts-file} field of an
13981 @code{operating-system} declaration (@pxref{operating-system Reference,
13982 @file{/etc/hosts}}):
13985 (use-modules (gnu) (guix))
13988 (host-name "mymachine")
13991 ;; Create a /etc/hosts file with aliases for "localhost"
13992 ;; and "mymachine", as well as for Facebook servers.
13993 (plain-file "hosts"
13994 (string-append (local-host-aliases host-name)
13995 %facebook-host-aliases))))
13998 This mechanism can prevent programs running locally, such as Web
13999 browsers, from accessing Facebook.
14002 The @code{(gnu services avahi)} provides the following definition.
14004 @defvr {Scheme Variable} avahi-service-type
14005 This is the service that runs @command{avahi-daemon}, a system-wide
14006 mDNS/DNS-SD responder that allows for service discovery and
14007 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14008 Its value must be a @code{zero-configuration} record---see below.
14010 This service extends the name service cache daemon (nscd) so that it can
14011 resolve @code{.local} host names using
14012 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14013 Service Switch}, for information on host name resolution.
14015 Additionally, add the @var{avahi} package to the system profile so that
14016 commands such as @command{avahi-browse} are directly usable.
14019 @deftp {Data Type} avahi-configuration
14020 Data type representation the configuration for Avahi.
14024 @item @code{host-name} (default: @code{#f})
14025 If different from @code{#f}, use that as the host name to
14026 publish for this machine; otherwise, use the machine's actual host name.
14028 @item @code{publish?} (default: @code{#t})
14029 When true, allow host names and services to be published (broadcast) over the
14032 @item @code{publish-workstation?} (default: @code{#t})
14033 When true, @command{avahi-daemon} publishes the machine's host name and IP
14034 address via mDNS on the local network. To view the host names published on
14035 your local network, you can run:
14038 avahi-browse _workstation._tcp
14041 @item @code{wide-area?} (default: @code{#f})
14042 When true, DNS-SD over unicast DNS is enabled.
14044 @item @code{ipv4?} (default: @code{#t})
14045 @itemx @code{ipv6?} (default: @code{#t})
14046 These fields determine whether to use IPv4/IPv6 sockets.
14048 @item @code{domains-to-browse} (default: @code{'()})
14049 This is a list of domains to browse.
14053 @deffn {Scheme Variable} openvswitch-service-type
14054 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14055 service, whose value should be an @code{openvswitch-configuration}
14059 @deftp {Data Type} openvswitch-configuration
14060 Data type representing the configuration of Open vSwitch, a multilayer
14061 virtual switch which is designed to enable massive network automation
14062 through programmatic extension.
14065 @item @code{package} (default: @var{openvswitch})
14066 Package object of the Open vSwitch.
14071 @defvr {Scheme Variable} pagekite-service-type
14072 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14073 a tunneling solution for making localhost servers publicly visible, even from
14074 behind NAT or restrictive firewalls. The value for this service type is a
14075 @code{pagekite-configuration} record.
14077 Here's an example exposing the local HTTP and SSH daemons:
14080 (service pagekite-service-type
14081 (pagekite-configuration
14082 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14083 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14084 (extra-file "/etc/pagekite.rc")))
14088 @deftp {Data Type} pagekite-configuration
14089 Data type representing the configuration of PageKite.
14092 @item @code{package} (default: @var{pagekite})
14093 Package object of PageKite.
14095 @item @code{kitename} (default: @code{#f})
14096 PageKite name for authenticating to the frontend server.
14098 @item @code{kitesecret} (default: @code{#f})
14099 Shared secret for authenticating to the frontend server. You should probably
14100 put this inside @code{extra-file} instead.
14102 @item @code{frontend} (default: @code{#f})
14103 Connect to the named PageKite frontend server instead of the
14104 @uref{https://pagekite.net,,pagekite.net} service.
14106 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14107 List of service kites to use. Exposes HTTP on port 80 by default. The format
14108 is @code{proto:kitename:host:port:secret}.
14110 @item @code{extra-file} (default: @code{#f})
14111 Extra configuration file to read, which you are expected to create manually.
14112 Use this to add additional options and manage shared secrets out-of-band.
14118 @subsection X Window
14121 @cindex X Window System
14122 @cindex login manager
14123 Support for the X Window graphical display system---specifically
14124 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14125 there is no @code{xorg-service} procedure. Instead, the X server is
14126 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14129 @cindex GNOME, login manager
14130 GDM of course allows users to log in into window managers and desktop
14131 environments other than GNOME; for those using GNOME, GDM is required for
14132 features such as automatic screen locking.
14134 @cindex window manager
14135 To use X11, you must install at least one @dfn{window manager}---for
14136 example the @code{windowmaker} or @code{openbox} packages---preferably
14137 by adding it to the @code{packages} field of your operating system
14138 definition (@pxref{operating-system Reference, system-wide packages}).
14140 @defvr {Scheme Variable} gdm-service-type
14141 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14142 Desktop Manager} (GDM), a program that manages graphical display servers and
14143 handles graphical user logins. Its value must be a @code{gdm-configuration}
14146 @cindex session types (X11)
14147 @cindex X11 session types
14148 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14149 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14150 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14151 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14152 set of packages automatically makes them available at the log-in screen.
14154 In addition, @file{~/.xsession} files are honored. When available,
14155 @file{~/.xsession} must be an executable that starts a window manager
14156 and/or other X clients.
14159 @deftp {Data Type} gdm-configuration
14161 @item @code{auto-login?} (default: @code{#f})
14162 @itemx @code{default-user} (default: @code{#f})
14163 When @code{auto-login?} is false, GDM presents a log-in screen.
14165 When @code{auto-login?} is true, GDM logs in directly as
14166 @code{default-user}.
14168 @item @code{debug?} (default: @code{#f})
14169 When true, GDM writes debug messages to its log.
14171 @item @code{gnome-shell-assets} (default: ...)
14172 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14174 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14175 Configuration of the Xorg graphical server.
14177 @item @code{xsession} (default: @code{(xinitrc)})
14178 Script to run before starting a X session.
14180 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14181 File name of the @code{dbus-daemon} executable.
14183 @item @code{gdm} (default: @code{gdm})
14184 The GDM package to use.
14188 @defvr {Scheme Variable} slim-service-type
14189 This is the type for the SLiM graphical login manager for X11.
14191 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14192 allows users to choose a session from the log-in screen using @kbd{F1}. It
14193 also honors @file{~/.xsession} files.
14195 Unlike GDM, SLiM does not spawn the user session on a different VT after
14196 logging in, which means that you can only start one graphical session. If you
14197 want to be able to run multiple graphical sessions at the same time you have
14198 to add multiple SLiM services to your system services. The following example
14199 shows how to replace the default GDM service with two SLiM services on tty7
14203 (use-modules (gnu services)
14204 (gnu services desktop)
14205 (gnu services xorg)
14206 (srfi srfi-1)) ;for 'remove'
14210 (services (cons* (service slim-service-type (slim-configuration
14213 (service slim-service-type (slim-configuration
14216 (remove (lambda (service)
14217 (eq? (service-kind service) gdm-service-type))
14218 %desktop-services))))
14223 @deftp {Data Type} slim-configuration
14224 Data type representing the configuration of @code{slim-service-type}.
14227 @item @code{allow-empty-passwords?} (default: @code{#t})
14228 Whether to allow logins with empty passwords.
14230 @item @code{auto-login?} (default: @code{#f})
14231 @itemx @code{default-user} (default: @code{""})
14232 When @code{auto-login?} is false, SLiM presents a log-in screen.
14234 When @code{auto-login?} is true, SLiM logs in directly as
14235 @code{default-user}.
14237 @item @code{theme} (default: @code{%default-slim-theme})
14238 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14239 The graphical theme to use and its name.
14241 @item @code{auto-login-session} (default: @code{#f})
14242 If true, this must be the name of the executable to start as the default
14243 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14245 If false, a session described by one of the available @file{.desktop}
14246 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14250 You must install at least one window manager in the system profile or in
14251 your user profile. Failing to do that, if @code{auto-login-session} is
14252 false, you will be unable to log in.
14255 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14256 Configuration of the Xorg graphical server.
14258 @item @code{display} (default @code{":0"})
14259 The display on which to start the Xorg graphical server.
14261 @item @code{vt} (default @code{"vt7"})
14262 The VT on which to start the Xorg graphical server.
14264 @item @code{xauth} (default: @code{xauth})
14265 The XAuth package to use.
14267 @item @code{shepherd} (default: @code{shepherd})
14268 The Shepherd package used when invoking @command{halt} and
14271 @item @code{sessreg} (default: @code{sessreg})
14272 The sessreg package used in order to register the session.
14274 @item @code{slim} (default: @code{slim})
14275 The SLiM package to use.
14279 @defvr {Scheme Variable} %default-theme
14280 @defvrx {Scheme Variable} %default-theme-name
14281 The default SLiM theme and its name.
14285 @deftp {Data Type} sddm-configuration
14286 This is the data type representing the sddm service configuration.
14289 @item @code{display-server} (default: "x11")
14290 Select display server to use for the greeter. Valid values are "x11"
14293 @item @code{numlock} (default: "on")
14294 Valid values are "on", "off" or "none".
14296 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14297 Command to run when halting.
14299 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14300 Command to run when rebooting.
14302 @item @code{theme} (default "maldives")
14303 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
14305 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14306 Directory to look for themes.
14308 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14309 Directory to look for faces.
14311 @item @code{default-path} (default "/run/current-system/profile/bin")
14312 Default PATH to use.
14314 @item @code{minimum-uid} (default: 1000)
14315 Minimum UID displayed in SDDM and allowed for log-in.
14317 @item @code{maximum-uid} (default: 2000)
14318 Maximum UID to display in SDDM.
14320 @item @code{remember-last-user?} (default #t)
14321 Remember last user.
14323 @item @code{remember-last-session?} (default #t)
14324 Remember last session.
14326 @item @code{hide-users} (default "")
14327 Usernames to hide from SDDM greeter.
14329 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14330 Users with shells listed will be hidden from the SDDM greeter.
14332 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14333 Script to run before starting a wayland session.
14335 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14336 Directory to look for desktop files starting wayland sessions.
14338 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14339 Configuration of the Xorg graphical server.
14341 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14344 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14347 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14348 Script to run after starting xorg-server.
14350 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14351 Script to run before stopping xorg-server.
14353 @item @code{xsession-command} (default: @code{xinitrc})
14354 Script to run before starting a X session.
14356 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14357 Directory to look for desktop files starting X sessions.
14359 @item @code{minimum-vt} (default: 7)
14362 @item @code{auto-login-user} (default "")
14363 User to use for auto-login.
14365 @item @code{auto-login-session} (default "")
14366 Desktop file to use for auto-login.
14368 @item @code{relogin?} (default #f)
14369 Relogin after logout.
14374 @cindex login manager
14376 @defvr {Scheme Variable} sddm-service-type
14377 This is the type of the service to run the
14378 @uref{https://github.com/sddm/sddm,SSDM display manager}. Its value
14379 must be a @code{sddm-configuration} record (see below).
14381 Here's an example use:
14384 (service sddm-service-type
14385 (sddm-configuration
14386 (auto-login-user "alice")
14387 (auto-login-session "xfce.desktop")))
14391 @deftp {Data Type} sddm-configuration
14392 This data type represents the configuration of the SDDM login manager.
14393 The available fields are:
14396 @item @code{sddm} (default: @code{sddm})
14397 The SDDM package to use.
14399 @item @code{display-server} (default: @code{"x11"})
14400 This must be either @code{"x11"} or @code{"wayland"}.
14402 @c FIXME: Add more fields.
14404 @item @code{auto-login-user} (default: @code{""})
14405 If non-empty, this is the user account under which to log in
14408 @item @code{auto-login-session} (default: @code{""})
14409 If non-empty, this is the @file{.desktop} file name to use as the
14410 auto-login session.
14414 @cindex Xorg, configuration
14415 @deftp {Data Type} xorg-configuration
14416 This data type represents the configuration of the Xorg graphical display
14417 server. Note that there is not Xorg service; instead, the X server is started
14418 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14419 of these display managers aggregates an @code{xorg-configuration} record.
14422 @item @code{modules} (default: @code{%default-xorg-modules})
14423 This is a list of @dfn{module packages} loaded by the Xorg
14424 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14426 @item @code{fonts} (default: @code{%default-xorg-fonts})
14427 This is a list of font directories to add to the server's @dfn{font path}.
14429 @item @code{drivers} (default: @code{'()})
14430 This must be either the empty list, in which case Xorg chooses a graphics
14431 driver automatically, or a list of driver names that will be tried in this
14432 order---e.g., @code{("modesetting" "vesa")}.
14434 @item @code{resolutions} (default: @code{'()})
14435 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14436 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14439 @cindex keyboard layout, for Xorg
14440 @cindex keymap, for Xorg
14441 @item @code{keyboard-layout} (default: @code{#f})
14442 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14443 English (``qwerty'') for a 105-key PC keyboard.
14445 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14446 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14447 information on how to specify the keyboard layout.
14449 @item @code{extra-config} (default: @code{'()})
14450 This is a list of strings or objects appended to the configuration file. It
14451 is used to pass extra text to be added verbatim to the configuration file.
14453 @item @code{server} (default: @code{xorg-server})
14454 This is the package providing the Xorg server.
14456 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14457 This is the list of command-line arguments to pass to the X server. The
14458 default is @code{-nolisten tcp}.
14462 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14463 [@var{login-manager-service-type}]
14464 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14465 @var{config}, an @code{<xorg-configuration>} record.
14467 Since the Xorg configuration is embedded in the log-in manager's
14468 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14469 shorthand to set the Xorg configuration.
14472 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14473 Return a @code{startx} script in which the modules, fonts, etc. specified
14474 in @var{config}, are available. The result should be used in place of
14477 Usually the X server is started by a login manager.
14481 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14482 Add @var{package}, a package for a screen locker or screen saver whose
14483 command is @var{program}, to the set of setuid programs and add a PAM entry
14484 for it. For example:
14487 (screen-locker-service xlockmore "xlock")
14490 makes the good ol' XlockMore usable.
14494 @node Printing Services
14495 @subsection Printing Services
14497 @cindex printer support with CUPS
14498 The @code{(gnu services cups)} module provides a Guix service definition
14499 for the CUPS printing service. To add printer support to a Guix
14500 system, add a @code{cups-service} to the operating system definition:
14502 @deffn {Scheme Variable} cups-service-type
14503 The service type for the CUPS print server. Its value should be a valid
14504 CUPS configuration (see below). To use the default settings, simply
14507 (service cups-service-type)
14511 The CUPS configuration controls the basic things about your CUPS
14512 installation: what interfaces it listens on, what to do if a print job
14513 fails, how much logging to do, and so on. To actually add a printer,
14514 you have to visit the @url{http://localhost:631} URL, or use a tool such
14515 as GNOME's printer configuration services. By default, configuring a
14516 CUPS service will generate a self-signed certificate if needed, for
14517 secure connections to the print server.
14519 Suppose you want to enable the Web interface of CUPS and also add
14520 support for Epson printers @i{via} the @code{escpr} package and for HP
14521 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14522 like this (you need to use the @code{(gnu packages cups)} module):
14525 (service cups-service-type
14526 (cups-configuration
14527 (web-interface? #t)
14529 (list cups-filters escpr hplip-minimal))))
14532 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14533 package then it is suggested that you install the @code{hplip} package,
14534 either in your OS configuration file or as your user.
14536 The available configuration parameters follow. Each parameter
14537 definition is preceded by its type; for example, @samp{string-list foo}
14538 indicates that the @code{foo} parameter should be specified as a list of
14539 strings. There is also a way to specify the configuration as a string,
14540 if you have an old @code{cupsd.conf} file that you want to port over
14541 from some other system; see the end for more details.
14543 @c The following documentation was initially generated by
14544 @c (generate-documentation) in (gnu services cups). Manually maintained
14545 @c documentation is better, so we shouldn't hesitate to edit below as
14546 @c needed. However if the change you want to make to this documentation
14547 @c can be done in an automated way, it's probably easier to change
14548 @c (generate-documentation) than to make it below and have to deal with
14549 @c the churn as CUPS updates.
14552 Available @code{cups-configuration} fields are:
14554 @deftypevr {@code{cups-configuration} parameter} package cups
14558 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14559 Drivers and other extensions to the CUPS package.
14562 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14563 Configuration of where to write logs, what directories to use for print
14564 spools, and related privileged configuration parameters.
14566 Available @code{files-configuration} fields are:
14568 @deftypevr {@code{files-configuration} parameter} log-location access-log
14569 Defines the access log filename. Specifying a blank filename disables
14570 access log generation. The value @code{stderr} causes log entries to be
14571 sent to the standard error file when the scheduler is running in the
14572 foreground, or to the system log daemon when run in the background. The
14573 value @code{syslog} causes log entries to be sent to the system log
14574 daemon. The server name may be included in filenames using the string
14575 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14577 Defaults to @samp{"/var/log/cups/access_log"}.
14580 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14581 Where CUPS should cache data.
14583 Defaults to @samp{"/var/cache/cups"}.
14586 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14587 Specifies the permissions for all configuration files that the scheduler
14590 Note that the permissions for the printers.conf file are currently
14591 masked to only allow access from the scheduler user (typically root).
14592 This is done because printer device URIs sometimes contain sensitive
14593 authentication information that should not be generally known on the
14594 system. There is no way to disable this security feature.
14596 Defaults to @samp{"0640"}.
14599 @deftypevr {@code{files-configuration} parameter} log-location error-log
14600 Defines the error log filename. Specifying a blank filename disables
14601 error log generation. The value @code{stderr} causes log entries to be
14602 sent to the standard error file when the scheduler is running in the
14603 foreground, or to the system log daemon when run in the background. The
14604 value @code{syslog} causes log entries to be sent to the system log
14605 daemon. The server name may be included in filenames using the string
14606 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14608 Defaults to @samp{"/var/log/cups/error_log"}.
14611 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14612 Specifies which errors are fatal, causing the scheduler to exit. The
14617 No errors are fatal.
14620 All of the errors below are fatal.
14623 Browsing initialization errors are fatal, for example failed connections
14624 to the DNS-SD daemon.
14627 Configuration file syntax errors are fatal.
14630 Listen or Port errors are fatal, except for IPv6 failures on the
14631 loopback or @code{any} addresses.
14634 Log file creation or write errors are fatal.
14637 Bad startup file permissions are fatal, for example shared TLS
14638 certificate and key files with world-read permissions.
14641 Defaults to @samp{"all -browse"}.
14644 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14645 Specifies whether the file pseudo-device can be used for new printer
14646 queues. The URI @uref{file:///dev/null} is always allowed.
14648 Defaults to @samp{#f}.
14651 @deftypevr {@code{files-configuration} parameter} string group
14652 Specifies the group name or ID that will be used when executing external
14655 Defaults to @samp{"lp"}.
14658 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14659 Specifies the permissions for all log files that the scheduler writes.
14661 Defaults to @samp{"0644"}.
14664 @deftypevr {@code{files-configuration} parameter} log-location page-log
14665 Defines the page log filename. Specifying a blank filename disables
14666 page log generation. The value @code{stderr} causes log entries to be
14667 sent to the standard error file when the scheduler is running in the
14668 foreground, or to the system log daemon when run in the background. The
14669 value @code{syslog} causes log entries to be sent to the system log
14670 daemon. The server name may be included in filenames using the string
14671 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14673 Defaults to @samp{"/var/log/cups/page_log"}.
14676 @deftypevr {@code{files-configuration} parameter} string remote-root
14677 Specifies the username that is associated with unauthenticated accesses
14678 by clients claiming to be the root user. The default is @code{remroot}.
14680 Defaults to @samp{"remroot"}.
14683 @deftypevr {@code{files-configuration} parameter} file-name request-root
14684 Specifies the directory that contains print jobs and other HTTP request
14687 Defaults to @samp{"/var/spool/cups"}.
14690 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14691 Specifies the level of security sandboxing that is applied to print
14692 filters, backends, and other child processes of the scheduler; either
14693 @code{relaxed} or @code{strict}. This directive is currently only
14694 used/supported on macOS.
14696 Defaults to @samp{strict}.
14699 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14700 Specifies the location of TLS certificates and private keys. CUPS will
14701 look for public and private keys in this directory: a @code{.crt} files
14702 for PEM-encoded certificates and corresponding @code{.key} files for
14703 PEM-encoded private keys.
14705 Defaults to @samp{"/etc/cups/ssl"}.
14708 @deftypevr {@code{files-configuration} parameter} file-name server-root
14709 Specifies the directory containing the server configuration files.
14711 Defaults to @samp{"/etc/cups"}.
14714 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14715 Specifies whether the scheduler calls fsync(2) after writing
14716 configuration or state files.
14718 Defaults to @samp{#f}.
14721 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14722 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14725 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14726 Specifies the directory where temporary files are stored.
14728 Defaults to @samp{"/var/spool/cups/tmp"}.
14731 @deftypevr {@code{files-configuration} parameter} string user
14732 Specifies the user name or ID that is used when running external
14735 Defaults to @samp{"lp"}.
14738 @deftypevr {@code{files-configuration} parameter} string set-env
14739 Set the specified environment variable to be passed to child processes.
14741 Defaults to @samp{"variable value"}.
14745 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14746 Specifies the logging level for the AccessLog file. The @code{config}
14747 level logs when printers and classes are added, deleted, or modified and
14748 when configuration files are accessed or updated. The @code{actions}
14749 level logs when print jobs are submitted, held, released, modified, or
14750 canceled, and any of the conditions for @code{config}. The @code{all}
14751 level logs all requests.
14753 Defaults to @samp{actions}.
14756 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14757 Specifies whether to purge job history data automatically when it is no
14758 longer required for quotas.
14760 Defaults to @samp{#f}.
14763 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
14764 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
14765 For example, @samp{"_cups" "_print"} will tell network clients that both
14766 CUPS sharing and IPP Everywhere are supported.
14768 Defaults to @samp{"_cups"}.
14771 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14772 Specifies which protocols to use for local printer sharing.
14774 Defaults to @samp{dnssd}.
14777 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14778 Specifies whether the CUPS web interface is advertised.
14780 Defaults to @samp{#f}.
14783 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14784 Specifies whether shared printers are advertised.
14786 Defaults to @samp{#f}.
14789 @deftypevr {@code{cups-configuration} parameter} string classification
14790 Specifies the security classification of the server. Any valid banner
14791 name can be used, including "classified", "confidential", "secret",
14792 "topsecret", and "unclassified", or the banner can be omitted to disable
14793 secure printing functions.
14795 Defaults to @samp{""}.
14798 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14799 Specifies whether users may override the classification (cover page) of
14800 individual print jobs using the @code{job-sheets} option.
14802 Defaults to @samp{#f}.
14805 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14806 Specifies the default type of authentication to use.
14808 Defaults to @samp{Basic}.
14811 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14812 Specifies whether encryption will be used for authenticated requests.
14814 Defaults to @samp{Required}.
14817 @deftypevr {@code{cups-configuration} parameter} string default-language
14818 Specifies the default language to use for text and web content.
14820 Defaults to @samp{"en"}.
14823 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14824 Specifies the default paper size for new print queues. @samp{"Auto"}
14825 uses a locale-specific default, while @samp{"None"} specifies there is
14826 no default paper size. Specific size names are typically
14827 @samp{"Letter"} or @samp{"A4"}.
14829 Defaults to @samp{"Auto"}.
14832 @deftypevr {@code{cups-configuration} parameter} string default-policy
14833 Specifies the default access policy to use.
14835 Defaults to @samp{"default"}.
14838 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14839 Specifies whether local printers are shared by default.
14841 Defaults to @samp{#t}.
14844 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14845 Specifies the delay for updating of configuration and state files, in
14846 seconds. A value of 0 causes the update to happen as soon as possible,
14847 typically within a few milliseconds.
14849 Defaults to @samp{30}.
14852 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14853 Specifies what to do when an error occurs. Possible values are
14854 @code{abort-job}, which will discard the failed print job;
14855 @code{retry-job}, which will retry the job at a later time;
14856 @code{retry-current-job}, which retries the failed job immediately; and
14857 @code{stop-printer}, which stops the printer.
14859 Defaults to @samp{stop-printer}.
14862 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14863 Specifies the maximum cost of filters that are run concurrently, which
14864 can be used to minimize disk, memory, and CPU resource problems. A
14865 limit of 0 disables filter limiting. An average print to a
14866 non-PostScript printer needs a filter limit of about 200. A PostScript
14867 printer needs about half that (100). Setting the limit below these
14868 thresholds will effectively limit the scheduler to printing a single job
14871 Defaults to @samp{0}.
14874 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14875 Specifies the scheduling priority of filters that are run to print a
14876 job. The nice value ranges from 0, the highest priority, to 19, the
14879 Defaults to @samp{0}.
14882 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14883 Specifies whether to do reverse lookups on connecting clients. The
14884 @code{double} setting causes @code{cupsd} to verify that the hostname
14885 resolved from the address matches one of the addresses returned for that
14886 hostname. Double lookups also prevent clients with unregistered
14887 addresses from connecting to your server. Only set this option to
14888 @code{#t} or @code{double} if absolutely required.
14890 Defaults to @samp{#f}.
14893 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14894 Specifies the number of seconds to wait before killing the filters and
14895 backend associated with a canceled or held job.
14897 Defaults to @samp{30}.
14900 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14901 Specifies the interval between retries of jobs in seconds. This is
14902 typically used for fax queues but can also be used with normal print
14903 queues whose error policy is @code{retry-job} or
14904 @code{retry-current-job}.
14906 Defaults to @samp{30}.
14909 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14910 Specifies the number of retries that are done for jobs. This is
14911 typically used for fax queues but can also be used with normal print
14912 queues whose error policy is @code{retry-job} or
14913 @code{retry-current-job}.
14915 Defaults to @samp{5}.
14918 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14919 Specifies whether to support HTTP keep-alive connections.
14921 Defaults to @samp{#t}.
14924 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14925 Specifies how long an idle client connection remains open, in seconds.
14927 Defaults to @samp{30}.
14930 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14931 Specifies the maximum size of print files, IPP requests, and HTML form
14932 data. A limit of 0 disables the limit check.
14934 Defaults to @samp{0}.
14937 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14938 Listens on the specified interfaces for connections. Valid values are
14939 of the form @var{address}:@var{port}, where @var{address} is either an
14940 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14941 indicate all addresses. Values can also be file names of local UNIX
14942 domain sockets. The Listen directive is similar to the Port directive
14943 but allows you to restrict access to specific interfaces or networks.
14946 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14947 Specifies the number of pending connections that will be allowed. This
14948 normally only affects very busy servers that have reached the MaxClients
14949 limit, but can also be triggered by large numbers of simultaneous
14950 connections. When the limit is reached, the operating system will
14951 refuse additional connections until the scheduler can accept the pending
14954 Defaults to @samp{128}.
14957 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14958 Specifies a set of additional access controls.
14960 Available @code{location-access-controls} fields are:
14962 @deftypevr {@code{location-access-controls} parameter} file-name path
14963 Specifies the URI path to which the access control applies.
14966 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14967 Access controls for all access to this path, in the same format as the
14968 @code{access-controls} of @code{operation-access-control}.
14970 Defaults to @samp{()}.
14973 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14974 Access controls for method-specific access to this path.
14976 Defaults to @samp{()}.
14978 Available @code{method-access-controls} fields are:
14980 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14981 If @code{#t}, apply access controls to all methods except the listed
14982 methods. Otherwise apply to only the listed methods.
14984 Defaults to @samp{#f}.
14987 @deftypevr {@code{method-access-controls} parameter} method-list methods
14988 Methods to which this access control applies.
14990 Defaults to @samp{()}.
14993 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14994 Access control directives, as a list of strings. Each string should be
14995 one directive, such as "Order allow,deny".
14997 Defaults to @samp{()}.
15002 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15003 Specifies the number of debugging messages that are retained for logging
15004 if an error occurs in a print job. Debug messages are logged regardless
15005 of the LogLevel setting.
15007 Defaults to @samp{100}.
15010 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15011 Specifies the level of logging for the ErrorLog file. The value
15012 @code{none} stops all logging while @code{debug2} logs everything.
15014 Defaults to @samp{info}.
15017 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15018 Specifies the format of the date and time in the log files. The value
15019 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15021 Defaults to @samp{standard}.
15024 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15025 Specifies the maximum number of simultaneous clients that are allowed by
15028 Defaults to @samp{100}.
15031 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15032 Specifies the maximum number of simultaneous clients that are allowed
15033 from a single address.
15035 Defaults to @samp{100}.
15038 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15039 Specifies the maximum number of copies that a user can print of each
15042 Defaults to @samp{9999}.
15045 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15046 Specifies the maximum time a job may remain in the @code{indefinite}
15047 hold state before it is canceled. A value of 0 disables cancellation of
15050 Defaults to @samp{0}.
15053 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15054 Specifies the maximum number of simultaneous jobs that are allowed. Set
15055 to 0 to allow an unlimited number of jobs.
15057 Defaults to @samp{500}.
15060 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15061 Specifies the maximum number of simultaneous jobs that are allowed per
15062 printer. A value of 0 allows up to MaxJobs jobs per printer.
15064 Defaults to @samp{0}.
15067 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15068 Specifies the maximum number of simultaneous jobs that are allowed per
15069 user. A value of 0 allows up to MaxJobs jobs per user.
15071 Defaults to @samp{0}.
15074 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15075 Specifies the maximum time a job may take to print before it is
15076 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
15078 Defaults to @samp{10800}.
15081 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15082 Specifies the maximum size of the log files before they are rotated, in
15083 bytes. The value 0 disables log rotation.
15085 Defaults to @samp{1048576}.
15088 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15089 Specifies the maximum amount of time to allow between files in a
15090 multiple file print job, in seconds.
15092 Defaults to @samp{300}.
15095 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15096 Specifies the format of PageLog lines. Sequences beginning with percent
15097 (@samp{%}) characters are replaced with the corresponding information,
15098 while all other characters are copied literally. The following percent
15099 sequences are recognized:
15103 insert a single percent character
15106 insert the value of the specified IPP attribute
15109 insert the number of copies for the current page
15112 insert the current page number
15115 insert the current date and time in common log format
15121 insert the printer name
15124 insert the username
15127 A value of the empty string disables page logging. The string @code{%p
15128 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15129 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15132 Defaults to @samp{""}.
15135 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15136 Passes the specified environment variable(s) to child processes; a list
15139 Defaults to @samp{()}.
15142 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15143 Specifies named access control policies.
15145 Available @code{policy-configuration} fields are:
15147 @deftypevr {@code{policy-configuration} parameter} string name
15148 Name of the policy.
15151 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15152 Specifies an access list for a job's private values. @code{@@ACL} maps
15153 to the printer's requesting-user-name-allowed or
15154 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15155 owner. @code{@@SYSTEM} maps to the groups listed for the
15156 @code{system-group} field of the @code{files-config} configuration,
15157 which is reified into the @code{cups-files.conf(5)} file. Other
15158 possible elements of the access list include specific user names, and
15159 @code{@@@var{group}} to indicate members of a specific group. The
15160 access list may also be simply @code{all} or @code{default}.
15162 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15165 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15166 Specifies the list of job values to make private, or @code{all},
15167 @code{default}, or @code{none}.
15169 Defaults to @samp{"job-name job-originating-host-name
15170 job-originating-user-name phone"}.
15173 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15174 Specifies an access list for a subscription's private values.
15175 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15176 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15177 owner. @code{@@SYSTEM} maps to the groups listed for the
15178 @code{system-group} field of the @code{files-config} configuration,
15179 which is reified into the @code{cups-files.conf(5)} file. Other
15180 possible elements of the access list include specific user names, and
15181 @code{@@@var{group}} to indicate members of a specific group. The
15182 access list may also be simply @code{all} or @code{default}.
15184 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15187 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15188 Specifies the list of job values to make private, or @code{all},
15189 @code{default}, or @code{none}.
15191 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15192 notify-subscriber-user-name notify-user-data"}.
15195 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15196 Access control by IPP operation.
15198 Defaults to @samp{()}.
15202 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15203 Specifies whether job files (documents) are preserved after a job is
15204 printed. If a numeric value is specified, job files are preserved for
15205 the indicated number of seconds after printing. Otherwise a boolean
15206 value applies indefinitely.
15208 Defaults to @samp{86400}.
15211 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15212 Specifies whether the job history is preserved after a job is printed.
15213 If a numeric value is specified, the job history is preserved for the
15214 indicated number of seconds after printing. If @code{#t}, the job
15215 history is preserved until the MaxJobs limit is reached.
15217 Defaults to @samp{#t}.
15220 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15221 Specifies the amount of time to wait for job completion before
15222 restarting the scheduler.
15224 Defaults to @samp{30}.
15227 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15228 Specifies the maximum amount of memory to use when converting documents
15229 into bitmaps for a printer.
15231 Defaults to @samp{"128m"}.
15234 @deftypevr {@code{cups-configuration} parameter} string server-admin
15235 Specifies the email address of the server administrator.
15237 Defaults to @samp{"root@@localhost.localdomain"}.
15240 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15241 The ServerAlias directive is used for HTTP Host header validation when
15242 clients connect to the scheduler from external interfaces. Using the
15243 special name @code{*} can expose your system to known browser-based DNS
15244 rebinding attacks, even when accessing sites through a firewall. If the
15245 auto-discovery of alternate names does not work, we recommend listing
15246 each alternate name with a ServerAlias directive instead of using
15249 Defaults to @samp{*}.
15252 @deftypevr {@code{cups-configuration} parameter} string server-name
15253 Specifies the fully-qualified host name of the server.
15255 Defaults to @samp{"localhost"}.
15258 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15259 Specifies what information is included in the Server header of HTTP
15260 responses. @code{None} disables the Server header. @code{ProductOnly}
15261 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15262 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15263 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15264 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15265 2.0.0 (@var{uname}) IPP/2.0}.
15267 Defaults to @samp{Minimal}.
15270 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15271 Listens on the specified interfaces for encrypted connections. Valid
15272 values are of the form @var{address}:@var{port}, where @var{address} is
15273 either an IPv6 address enclosed in brackets, an IPv4 address, or
15274 @code{*} to indicate all addresses.
15276 Defaults to @samp{()}.
15279 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15280 Sets encryption options. By default, CUPS only supports encryption
15281 using TLS v1.0 or higher using known secure cipher suites. Security is
15282 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15283 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15284 suites, which are required for some older clients. The @code{AllowSSL3} option
15285 enables SSL v3.0, which is required for some older clients that do not support
15286 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15287 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15288 protocol version to TLS v1.1.
15290 Defaults to @samp{()}.
15293 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15294 Specifies whether the scheduler requires clients to strictly adhere to
15295 the IPP specifications.
15297 Defaults to @samp{#f}.
15300 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15301 Specifies the HTTP request timeout, in seconds.
15303 Defaults to @samp{300}.
15307 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15308 Specifies whether the web interface is enabled.
15310 Defaults to @samp{#f}.
15313 At this point you're probably thinking ``oh dear, Guix manual, I like
15314 you but you can stop already with the configuration options''. Indeed.
15315 However, one more point: it could be that you have an existing
15316 @code{cupsd.conf} that you want to use. In that case, you can pass an
15317 @code{opaque-cups-configuration} as the configuration of a
15318 @code{cups-service-type}.
15320 Available @code{opaque-cups-configuration} fields are:
15322 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15326 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15327 The contents of the @code{cupsd.conf}, as a string.
15330 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15331 The contents of the @code{cups-files.conf} file, as a string.
15334 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15335 strings of the same name, you could instantiate a CUPS service like
15339 (service cups-service-type
15340 (opaque-cups-configuration
15341 (cupsd.conf cupsd.conf)
15342 (cups-files.conf cups-files.conf)))
15346 @node Desktop Services
15347 @subsection Desktop Services
15349 The @code{(gnu services desktop)} module provides services that are
15350 usually useful in the context of a ``desktop'' setup---that is, on a
15351 machine running a graphical display server, possibly with graphical user
15352 interfaces, etc. It also defines services that provide specific desktop
15353 environments like GNOME, Xfce or MATE.
15355 To simplify things, the module defines a variable containing the set of
15356 services that users typically expect on a machine with a graphical
15357 environment and networking:
15359 @defvr {Scheme Variable} %desktop-services
15360 This is a list of services that builds upon @code{%base-services} and
15361 adds or adjusts services for a typical ``desktop'' setup.
15363 In particular, it adds a graphical login manager (@pxref{X Window,
15364 @code{gdm-service-type}}), screen lockers, a network management tool
15365 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15366 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15367 energy and color management services, the @code{elogind} login and seat
15368 manager, the Polkit privilege service, the GeoClue location service, the
15369 AccountsService daemon that allows authorized users change system passwords,
15370 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15371 name service switch service configured to be able to use @code{nss-mdns}
15372 (@pxref{Name Service Switch, mDNS}).
15375 The @code{%desktop-services} variable can be used as the @code{services}
15376 field of an @code{operating-system} declaration (@pxref{operating-system
15377 Reference, @code{services}}).
15379 Additionally, the @code{gnome-desktop-service-type},
15380 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15381 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15382 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15383 services like the backlight adjustment helpers and the power management
15384 utilities are added to the system, extending @code{polkit} and @code{dbus}
15385 appropriately, allowing GNOME to operate with elevated privileges on a
15386 limited number of special-purpose system interfaces. Additionally,
15387 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15388 metapackage to the system profile. Likewise, adding the Xfce service
15389 not only adds the @code{xfce} metapackage to the system profile, but it
15390 also gives the Thunar file manager the ability to open a ``root-mode''
15391 file management window, if the user authenticates using the
15392 administrator's password via the standard polkit graphical interface.
15393 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15394 appropriately, allowing MATE to operate with elevated privileges on a
15395 limited number of special-purpose system interfaces. Additionally,
15396 adding a service of type @code{mate-desktop-service-type} adds the MATE
15397 metapackage to the system profile. ``Adding Enlightenment'' means that
15398 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15399 are set as setuid, allowing Enlightenment's screen locker and other
15400 functionality to work as expetected.
15402 The desktop environments in Guix use the Xorg display server by
15403 default. If you'd like to use the newer display server protocol
15404 called Wayland, you need to use the @code{sddm-service} instead of
15405 GDM as the graphical login manager. You should then
15406 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15407 also try starting GNOME on Wayland manually from a TTY with the
15408 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15409 gnome-session``. Currently only GNOME has support for Wayland.
15411 @defvr {Scheme Variable} gnome-desktop-service-type
15412 This is the type of the service that adds the @uref{https://www.gnome.org,
15413 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15414 object (see below.)
15416 This service adds the @code{gnome} package to the system profile, and extends
15417 polkit with the actions from @code{gnome-settings-daemon}.
15420 @deftp {Data Type} gnome-desktop-configuration
15421 Configuration record for the GNOME desktop environment.
15424 @item @code{gnome} (default: @code{gnome})
15425 The GNOME package to use.
15429 @defvr {Scheme Variable} xfce-desktop-service-type
15430 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15431 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15434 This service adds the @code{xfce} package to the system profile, and
15435 extends polkit with the ability for @code{thunar} to manipulate the file
15436 system as root from within a user session, after the user has authenticated
15437 with the administrator's password.
15440 @deftp {Data Type} xfce-desktop-configuration
15441 Configuration record for the Xfce desktop environment.
15444 @item @code{xfce} (default: @code{xfce})
15445 The Xfce package to use.
15449 @deffn {Scheme Variable} mate-desktop-service-type
15450 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15451 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15452 object (see below.)
15454 This service adds the @code{mate} package to the system
15455 profile, and extends polkit with the actions from
15456 @code{mate-settings-daemon}.
15459 @deftp {Data Type} mate-desktop-configuration
15460 Configuration record for the MATE desktop environment.
15463 @item @code{mate} (default: @code{mate})
15464 The MATE package to use.
15468 @deffn {Scheme Variable} enlightenment-desktop-service-type
15469 Return a service that adds the @code{enlightenment} package to the system
15470 profile, and extends dbus with actions from @code{efl}.
15473 @deftp {Data Type} enlightenment-desktop-service-configuration
15475 @item @code{enlightenment} (default: @code{enlightenment})
15476 The enlightenment package to use.
15480 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15481 the default @code{%desktop-services} variable doesn't include any of
15482 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15483 @code{%desktop-services} in the @code{services} field of your
15484 @code{operating-system}:
15487 (use-modules (gnu))
15488 (use-service-modules desktop)
15491 ;; cons* adds items to the list given as its last argument.
15492 (services (cons* (service gnome-desktop-service-type)
15493 (service xfce-desktop-service)
15494 %desktop-services))
15498 These desktop environments will then be available as options in the
15499 graphical login window.
15501 The actual service definitions included in @code{%desktop-services} and
15502 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15503 are described below.
15505 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
15506 Return a service that runs the ``system bus'', using @var{dbus}, with
15507 support for @var{services}.
15509 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
15510 facility. Its system bus is used to allow system services to communicate
15511 and to be notified of system-wide events.
15513 @var{services} must be a list of packages that provide an
15514 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
15515 and policy files. For example, to allow avahi-daemon to use the system bus,
15516 @var{services} must be equal to @code{(list avahi)}.
15519 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
15520 Return a service that runs the @code{elogind} login and
15521 seat management daemon. @uref{https://github.com/elogind/elogind,
15522 Elogind} exposes a D-Bus interface that can be used to know which users
15523 are logged in, know what kind of sessions they have open, suspend the
15524 system, inhibit system suspend, reboot the system, and other tasks.
15526 Elogind handles most system-level power events for a computer, for
15527 example suspending the system when a lid is closed, or shutting it down
15528 when the power button is pressed.
15530 The @var{config} keyword argument specifies the configuration for
15531 elogind, and should be the result of an @code{(elogind-configuration
15532 (@var{parameter} @var{value})...)} invocation. Available parameters and
15533 their default values are:
15536 @item kill-user-processes?
15538 @item kill-only-users
15540 @item kill-exclude-users
15542 @item inhibit-delay-max-seconds
15544 @item handle-power-key
15546 @item handle-suspend-key
15548 @item handle-hibernate-key
15550 @item handle-lid-switch
15552 @item handle-lid-switch-docked
15554 @item power-key-ignore-inhibited?
15556 @item suspend-key-ignore-inhibited?
15558 @item hibernate-key-ignore-inhibited?
15560 @item lid-switch-ignore-inhibited?
15562 @item holdoff-timeout-seconds
15566 @item idle-action-seconds
15568 @item runtime-directory-size-percent
15570 @item runtime-directory-size
15574 @item suspend-state
15575 @code{("mem" "standby" "freeze")}
15578 @item hibernate-state
15580 @item hibernate-mode
15581 @code{("platform" "shutdown")}
15582 @item hybrid-sleep-state
15584 @item hybrid-sleep-mode
15585 @code{("suspend" "platform" "shutdown")}
15589 @deffn {Scheme Procedure} accountsservice-service @
15590 [#:accountsservice @var{accountsservice}]
15591 Return a service that runs AccountsService, a system service that can
15592 list available accounts, change their passwords, and so on.
15593 AccountsService integrates with PolicyKit to enable unprivileged users
15594 to acquire the capability to modify their system configuration.
15595 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15596 accountsservice web site} for more information.
15598 The @var{accountsservice} keyword argument is the @code{accountsservice}
15599 package to expose as a service.
15602 @deffn {Scheme Procedure} polkit-service @
15603 [#:polkit @var{polkit}]
15604 Return a service that runs the
15605 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15606 management service}, which allows system administrators to grant access to
15607 privileged operations in a structured way. By querying the Polkit service, a
15608 privileged system component can know when it should grant additional
15609 capabilities to ordinary users. For example, an ordinary user can be granted
15610 the capability to suspend the system if the user is logged in locally.
15613 @defvr {Scheme Variable} polkit-wheel-service
15614 Service that adds the @code{wheel} group as admins to the Polkit
15615 service. This makes it so that users in the @code{wheel} group are queried
15616 for their own passwords when performing administrative actions instead of
15617 @code{root}'s, similar to the behaviour used by @code{sudo}.
15620 @defvr {Scheme Variable} upower-service-type
15621 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15622 system-wide monitor for power consumption and battery levels, with the given
15623 configuration settings.
15625 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15626 notably used by GNOME.
15629 @deftp {Data Type} upower-configuration
15630 Data type representation the configuration for UPower.
15634 @item @code{upower} (default: @var{upower})
15635 Package to use for @code{upower}.
15637 @item @code{watts-up-pro?} (default: @code{#f})
15638 Enable the Watts Up Pro device.
15640 @item @code{poll-batteries?} (default: @code{#t})
15641 Enable polling the kernel for battery level changes.
15643 @item @code{ignore-lid?} (default: @code{#f})
15644 Ignore the lid state, this can be useful if it's incorrect on a device.
15646 @item @code{use-percentage-for-policy?} (default: @code{#f})
15647 Whether battery percentage based policy should be used. The default is to use
15648 the time left, change to @code{#t} to use the percentage.
15650 @item @code{percentage-low} (default: @code{10})
15651 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15652 at which the battery is considered low.
15654 @item @code{percentage-critical} (default: @code{3})
15655 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15656 at which the battery is considered critical.
15658 @item @code{percentage-action} (default: @code{2})
15659 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15660 at which action will be taken.
15662 @item @code{time-low} (default: @code{1200})
15663 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15664 seconds at which the battery is considered low.
15666 @item @code{time-critical} (default: @code{300})
15667 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15668 seconds at which the battery is considered critical.
15670 @item @code{time-action} (default: @code{120})
15671 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15672 seconds at which action will be taken.
15674 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15675 The action taken when @code{percentage-action} or @code{time-action} is
15676 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15678 Possible values are:
15688 @code{'hybrid-sleep}.
15694 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15695 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15696 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15697 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15698 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15701 @deffn {Scheme Variable} colord-service-type
15702 This is the type of the service that runs @command{colord}, a system
15703 service with a D-Bus
15704 interface to manage the color profiles of input and output devices such as
15705 screens and scanners. It is notably used by the GNOME Color Manager graphical
15706 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15707 site} for more information.
15710 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15711 Return a configuration allowing an application to access GeoClue
15712 location data. @var{name} is the Desktop ID of the application, without
15713 the @code{.desktop} part. If @var{allowed?} is true, the application
15714 will have access to location information by default. The boolean
15715 @var{system?} value indicates whether an application is a system component
15716 or not. Finally @var{users} is a list of UIDs of all users for which
15717 this application is allowed location info access. An empty users list
15718 means that all users are allowed.
15721 @defvr {Scheme Variable} %standard-geoclue-applications
15722 The standard list of well-known GeoClue application configurations,
15723 granting authority to the GNOME date-and-time utility to ask for the
15724 current location in order to set the time zone, and allowing the
15725 IceCat and Epiphany web browsers to request location information.
15726 IceCat and Epiphany both query the user before allowing a web page to
15727 know the user's location.
15730 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15731 [#:whitelist '()] @
15732 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15733 [#:submit-data? #f]
15734 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15735 [#:submission-nick "geoclue"] @
15736 [#:applications %standard-geoclue-applications]
15737 Return a service that runs the GeoClue location service. This service
15738 provides a D-Bus interface to allow applications to request access to a
15739 user's physical location, and optionally to add information to online
15740 location databases. See
15741 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15742 web site} for more information.
15745 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15746 [@w{#:auto-enable? #f}]
15747 Return a service that runs the @command{bluetoothd} daemon, which
15748 manages all the Bluetooth devices and provides a number of D-Bus
15749 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15750 powered automatically at boot, which can be useful when using a
15751 bluetooth keyboard or mouse.
15753 Users need to be in the @code{lp} group to access the D-Bus service.
15756 @defvr {Scheme Variable} gnome-keyring-service-type
15757 This is the type of the service that adds the
15758 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
15759 value is a @code{gnome-keyring-configuration} object (see below.)
15761 This service adds the @code{gnome-keyring} package to the system profile
15762 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
15763 a user's login keyring when they log in or setting its password with passwd.
15766 @deftp {Data Type} gnome-keyring-configuration
15767 Configuration record for the GNOME Keyring service.
15770 @item @code{keyring} (default: @code{gnome-keyring})
15771 The GNOME keyring package to use.
15773 @item @code{pam-services}
15774 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
15775 services to extend, where @var{service} is the name of an existing
15776 service to extend and @var{kind} is one of @code{login} or
15779 If @code{login} is given, it adds an optional
15780 @code{pam_gnome_keyring.so} to the auth block without arguments and to
15781 the session block with @code{auto_start}. If @code{passwd} is given, it
15782 adds an optional @code{pam_gnome_keyring.so} to the password block
15785 By default, this field contains ``gdm-password'' with the value @code{login}
15786 and ``passwd'' is with the value @code{passwd}.
15791 @node Sound Services
15792 @subsection Sound Services
15794 @cindex sound support
15796 @cindex PulseAudio, sound support
15798 The @code{(gnu services sound)} module provides a service to configure the
15799 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15800 preferred ALSA output driver.
15802 @deffn {Scheme Variable} alsa-service-type
15803 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15804 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15805 configuration file. The value for this type is a @command{alsa-configuration}
15806 record as in this example:
15809 (service alsa-service-type)
15812 See below for details about @code{alsa-configuration}.
15815 @deftp {Data Type} alsa-configuration
15816 Data type representing the configuration for @code{alsa-service}.
15819 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15820 @code{alsa-plugins} package to use.
15822 @item @code{pulseaudio?} (default: @var{#t})
15823 Whether ALSA applications should transparently be made to use the
15824 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15826 Using PulseAudio allows you to run several sound-producing applications
15827 at the same time and to individual control them @i{via}
15828 @command{pavucontrol}, among other things.
15830 @item @code{extra-options} (default: @var{""})
15831 String to append to the @file{/etc/asound.conf} file.
15836 Individual users who want to override the system configuration of ALSA can do
15837 it with the @file{~/.asoundrc} file:
15840 # In guix, we have to specify the absolute path for plugins.
15842 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15845 # Routing ALSA to jack:
15846 # <http://jackaudio.org/faq/routing_alsa.html>.
15850 0 system:playback_1
15851 1 system:playback_2
15868 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15872 @node Database Services
15873 @subsection Database Services
15877 The @code{(gnu services databases)} module provides the following services.
15879 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15880 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15881 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15882 Return a service that runs @var{postgresql}, the PostgreSQL database
15885 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15886 creates a database cluster with @var{locale} as the default
15887 locale, stored in @var{data-directory}. It then listens on @var{port}.
15889 @cindex postgresql extension-packages
15890 Additional extensions are loaded from packages listed in
15891 @var{extension-packages}. Extensions are available at runtime. For instance,
15892 to create a geographic database using the @code{postgis} extension, a user can
15893 configure the postgresql-service as in this example:
15897 (use-package-modules databases geo)
15901 ;; postgresql is required to run `psql' but postgis is not required for
15902 ;; proper operation.
15903 (packages (cons* postgresql %base-packages))
15906 (postgresql-service #:extension-packages (list postgis))
15910 Then the extension becomes visible and you can initialise an empty geographic
15911 database in this way:
15915 > create database postgistest;
15916 > \connect postgistest;
15917 > create extension postgis;
15918 > create extension postgis_topology;
15921 There is no need to add this field for contrib extensions such as hstore or
15922 dblink as they are already loadable by postgresql. This field is only
15923 required to add extensions provided by other packages.
15926 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15927 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15930 The optional @var{config} argument specifies the configuration for
15931 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15934 @deftp {Data Type} mysql-configuration
15935 Data type representing the configuration of @var{mysql-service}.
15938 @item @code{mysql} (default: @var{mariadb})
15939 Package object of the MySQL database server, can be either @var{mariadb}
15942 For MySQL, a temporary root password will be displayed at activation time.
15943 For MariaDB, the root password is empty.
15945 @item @code{port} (default: @code{3306})
15946 TCP port on which the database server listens for incoming connections.
15950 @defvr {Scheme Variable} memcached-service-type
15951 This is the service type for the @uref{https://memcached.org/,
15952 Memcached} service, which provides a distributed in memory cache. The
15953 value for the service type is a @code{memcached-configuration} object.
15957 (service memcached-service-type)
15960 @deftp {Data Type} memcached-configuration
15961 Data type representing the configuration of memcached.
15964 @item @code{memcached} (default: @code{memcached})
15965 The Memcached package to use.
15967 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15968 Network interfaces on which to listen.
15970 @item @code{tcp-port} (default: @code{11211})
15971 Port on which to accept connections on,
15973 @item @code{udp-port} (default: @code{11211})
15974 Port on which to accept UDP connections on, a value of 0 will disable
15975 listening on a UDP socket.
15977 @item @code{additional-options} (default: @code{'()})
15978 Additional command line options to pass to @code{memcached}.
15982 @defvr {Scheme Variable} mongodb-service-type
15983 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15984 The value for the service type is a @code{mongodb-configuration} object.
15988 (service mongodb-service-type)
15991 @deftp {Data Type} mongodb-configuration
15992 Data type representing the configuration of mongodb.
15995 @item @code{mongodb} (default: @code{mongodb})
15996 The MongoDB package to use.
15998 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15999 The configuration file for MongoDB.
16001 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16002 This value is used to create the directory, so that it exists and is
16003 owned by the mongodb user. It should match the data-directory which
16004 MongoDB is configured to use through the configuration file.
16008 @defvr {Scheme Variable} redis-service-type
16009 This is the service type for the @uref{https://redis.io/, Redis}
16010 key/value store, whose value is a @code{redis-configuration} object.
16013 @deftp {Data Type} redis-configuration
16014 Data type representing the configuration of redis.
16017 @item @code{redis} (default: @code{redis})
16018 The Redis package to use.
16020 @item @code{bind} (default: @code{"127.0.0.1"})
16021 Network interface on which to listen.
16023 @item @code{port} (default: @code{6379})
16024 Port on which to accept connections on, a value of 0 will disable
16025 listening on a TCP socket.
16027 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16028 Directory in which to store the database and related files.
16032 @node Mail Services
16033 @subsection Mail Services
16037 The @code{(gnu services mail)} module provides Guix service definitions
16038 for email services: IMAP, POP3, and LMTP servers, as well as mail
16039 transport agents (MTAs). Lots of acronyms! These services are detailed
16040 in the subsections below.
16042 @subsubheading Dovecot Service
16044 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16045 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16048 By default, Dovecot does not need much configuration; the default
16049 configuration object created by @code{(dovecot-configuration)} will
16050 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16051 certificate will be generated for TLS-protected connections, though
16052 Dovecot will also listen on cleartext ports by default. There are a
16053 number of options, though, which mail administrators might need to change,
16054 and as is the case with other services, Guix allows the system
16055 administrator to specify these parameters via a uniform Scheme interface.
16057 For example, to specify that mail is located at @code{maildir~/.mail},
16058 one would instantiate the Dovecot service like this:
16061 (dovecot-service #:config
16062 (dovecot-configuration
16063 (mail-location "maildir:~/.mail")))
16066 The available configuration parameters follow. Each parameter
16067 definition is preceded by its type; for example, @samp{string-list foo}
16068 indicates that the @code{foo} parameter should be specified as a list of
16069 strings. There is also a way to specify the configuration as a string,
16070 if you have an old @code{dovecot.conf} file that you want to port over
16071 from some other system; see the end for more details.
16073 @c The following documentation was initially generated by
16074 @c (generate-documentation) in (gnu services mail). Manually maintained
16075 @c documentation is better, so we shouldn't hesitate to edit below as
16076 @c needed. However if the change you want to make to this documentation
16077 @c can be done in an automated way, it's probably easier to change
16078 @c (generate-documentation) than to make it below and have to deal with
16079 @c the churn as dovecot updates.
16081 Available @code{dovecot-configuration} fields are:
16083 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16084 The dovecot package.
16087 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16088 A list of IPs or hosts where to listen for connections. @samp{*}
16089 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16090 interfaces. If you want to specify non-default ports or anything more
16091 complex, customize the address and port fields of the
16092 @samp{inet-listener} of the specific services you are interested in.
16095 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16096 List of protocols we want to serve. Available protocols include
16097 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16099 Available @code{protocol-configuration} fields are:
16101 @deftypevr {@code{protocol-configuration} parameter} string name
16102 The name of the protocol.
16105 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16106 UNIX socket path to the master authentication server to find users.
16107 This is used by imap (for shared users) and lda.
16108 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16111 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16112 Space separated list of plugins to load.
16115 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16116 Maximum number of IMAP connections allowed for a user from each IP
16117 address. NOTE: The username is compared case-sensitively.
16118 Defaults to @samp{10}.
16123 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16124 List of services to enable. Available services include @samp{imap},
16125 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16128 Available @code{service-configuration} fields are:
16130 @deftypevr {@code{service-configuration} parameter} string kind
16131 The service kind. Valid values include @code{director},
16132 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16133 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16134 @code{tcpwrap}, @code{quota-warning}, or anything else.
16137 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16138 Listeners for the service. A listener is either a
16139 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16140 an @code{inet-listener-configuration}.
16141 Defaults to @samp{()}.
16143 Available @code{unix-listener-configuration} fields are:
16145 @deftypevr {@code{unix-listener-configuration} parameter} string path
16146 Path to the file, relative to @code{base-dir} field. This is also used as
16150 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16151 The access mode for the socket.
16152 Defaults to @samp{"0600"}.
16155 @deftypevr {@code{unix-listener-configuration} parameter} string user
16156 The user to own the socket.
16157 Defaults to @samp{""}.
16160 @deftypevr {@code{unix-listener-configuration} parameter} string group
16161 The group to own the socket.
16162 Defaults to @samp{""}.
16166 Available @code{fifo-listener-configuration} fields are:
16168 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16169 Path to the file, relative to @code{base-dir} field. This is also used as
16173 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16174 The access mode for the socket.
16175 Defaults to @samp{"0600"}.
16178 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16179 The user to own the socket.
16180 Defaults to @samp{""}.
16183 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16184 The group to own the socket.
16185 Defaults to @samp{""}.
16189 Available @code{inet-listener-configuration} fields are:
16191 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16192 The protocol to listen for.
16195 @deftypevr {@code{inet-listener-configuration} parameter} string address
16196 The address on which to listen, or empty for all addresses.
16197 Defaults to @samp{""}.
16200 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16201 The port on which to listen.
16204 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16205 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16207 Defaults to @samp{#t}.
16212 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16213 Maximum number of simultaneous client connections per process. Once
16214 this number of connections is received, the next incoming connection
16215 will prompt Dovecot to spawn another process. If set to 0,
16216 @code{default-client-limit} is used instead.
16218 Defaults to @samp{0}.
16222 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16223 Number of connections to handle before starting a new process.
16224 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16225 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16226 Defaults to @samp{1}.
16230 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16231 Maximum number of processes that can exist for this service. If set to
16232 0, @code{default-process-limit} is used instead.
16234 Defaults to @samp{0}.
16238 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16239 Number of processes to always keep waiting for more connections.
16240 Defaults to @samp{0}.
16243 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16244 If you set @samp{service-count 0}, you probably need to grow
16246 Defaults to @samp{256000000}.
16251 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16252 Dict configuration, as created by the @code{dict-configuration}
16255 Available @code{dict-configuration} fields are:
16257 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16258 A list of key-value pairs that this dict should hold.
16259 Defaults to @samp{()}.
16264 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16265 A list of passdb configurations, each one created by the
16266 @code{passdb-configuration} constructor.
16268 Available @code{passdb-configuration} fields are:
16270 @deftypevr {@code{passdb-configuration} parameter} string driver
16271 The driver that the passdb should use. Valid values include
16272 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16274 Defaults to @samp{"pam"}.
16277 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16278 Space separated list of arguments to the passdb driver.
16279 Defaults to @samp{""}.
16284 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16285 List of userdb configurations, each one created by the
16286 @code{userdb-configuration} constructor.
16288 Available @code{userdb-configuration} fields are:
16290 @deftypevr {@code{userdb-configuration} parameter} string driver
16291 The driver that the userdb should use. Valid values include
16292 @samp{passwd} and @samp{static}.
16293 Defaults to @samp{"passwd"}.
16296 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16297 Space separated list of arguments to the userdb driver.
16298 Defaults to @samp{""}.
16301 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16302 Override fields from passwd.
16303 Defaults to @samp{()}.
16308 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16309 Plug-in configuration, created by the @code{plugin-configuration}
16313 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16314 List of namespaces. Each item in the list is created by the
16315 @code{namespace-configuration} constructor.
16317 Available @code{namespace-configuration} fields are:
16319 @deftypevr {@code{namespace-configuration} parameter} string name
16320 Name for this namespace.
16323 @deftypevr {@code{namespace-configuration} parameter} string type
16324 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16325 Defaults to @samp{"private"}.
16328 @deftypevr {@code{namespace-configuration} parameter} string separator
16329 Hierarchy separator to use. You should use the same separator for
16330 all namespaces or some clients get confused. @samp{/} is usually a good
16331 one. The default however depends on the underlying mail storage
16333 Defaults to @samp{""}.
16336 @deftypevr {@code{namespace-configuration} parameter} string prefix
16337 Prefix required to access this namespace. This needs to be
16338 different for all namespaces. For example @samp{Public/}.
16339 Defaults to @samp{""}.
16342 @deftypevr {@code{namespace-configuration} parameter} string location
16343 Physical location of the mailbox. This is in the same format as
16344 mail_location, which is also the default for it.
16345 Defaults to @samp{""}.
16348 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16349 There can be only one INBOX, and this setting defines which
16351 Defaults to @samp{#f}.
16354 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16355 If namespace is hidden, it's not advertised to clients via NAMESPACE
16356 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16357 useful when converting from another server with different namespaces
16358 which you want to deprecate but still keep working. For example you can
16359 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16361 Defaults to @samp{#f}.
16364 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16365 Show the mailboxes under this namespace with the LIST command. This
16366 makes the namespace visible for clients that do not support the NAMESPACE
16367 extension. The special @code{children} value lists child mailboxes, but
16368 hides the namespace prefix.
16369 Defaults to @samp{#t}.
16372 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16373 Namespace handles its own subscriptions. If set to @code{#f}, the
16374 parent namespace handles them. The empty prefix should always have this
16376 Defaults to @samp{#t}.
16379 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16380 List of predefined mailboxes in this namespace.
16381 Defaults to @samp{()}.
16383 Available @code{mailbox-configuration} fields are:
16385 @deftypevr {@code{mailbox-configuration} parameter} string name
16386 Name for this mailbox.
16389 @deftypevr {@code{mailbox-configuration} parameter} string auto
16390 @samp{create} will automatically create this mailbox.
16391 @samp{subscribe} will both create and subscribe to the mailbox.
16392 Defaults to @samp{"no"}.
16395 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16396 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16397 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16398 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16399 Defaults to @samp{()}.
16406 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16407 Base directory where to store runtime data.
16408 Defaults to @samp{"/var/run/dovecot/"}.
16411 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16412 Greeting message for clients.
16413 Defaults to @samp{"Dovecot ready."}.
16416 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16417 List of trusted network ranges. Connections from these IPs are
16418 allowed to override their IP addresses and ports (for logging and for
16419 authentication checks). @samp{disable-plaintext-auth} is also ignored
16420 for these networks. Typically you would specify your IMAP proxy servers
16422 Defaults to @samp{()}.
16425 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16426 List of login access check sockets (e.g.@: tcpwrap).
16427 Defaults to @samp{()}.
16430 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16431 Show more verbose process titles (in ps). Currently shows user name
16432 and IP address. Useful for seeing who is actually using the IMAP
16433 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16435 Defaults to @samp{#f}.
16438 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
16439 Should all processes be killed when Dovecot master process shuts down.
16440 Setting this to @code{#f} means that Dovecot can be upgraded without
16441 forcing existing client connections to close (although that could also
16442 be a problem if the upgrade is e.g.@: due to a security fix).
16443 Defaults to @samp{#t}.
16446 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
16447 If non-zero, run mail commands via this many connections to doveadm
16448 server, instead of running them directly in the same process.
16449 Defaults to @samp{0}.
16452 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
16453 UNIX socket or host:port used for connecting to doveadm server.
16454 Defaults to @samp{"doveadm-server"}.
16457 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
16458 List of environment variables that are preserved on Dovecot startup
16459 and passed down to all of its child processes. You can also give
16460 key=value pairs to always set specific settings.
16463 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
16464 Disable LOGIN command and all other plaintext authentications unless
16465 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
16466 matches the local IP (i.e.@: you're connecting from the same computer),
16467 the connection is considered secure and plaintext authentication is
16468 allowed. See also ssl=required setting.
16469 Defaults to @samp{#t}.
16472 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
16473 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
16474 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
16475 for caching to be used.
16476 Defaults to @samp{0}.
16479 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
16480 Time to live for cached data. After TTL expires the cached record
16481 is no longer used, *except* if the main database lookup returns internal
16482 failure. We also try to handle password changes automatically: If
16483 user's previous authentication was successful, but this one wasn't, the
16484 cache isn't used. For now this works only with plaintext
16486 Defaults to @samp{"1 hour"}.
16489 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
16490 TTL for negative hits (user not found, password mismatch).
16491 0 disables caching them completely.
16492 Defaults to @samp{"1 hour"}.
16495 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
16496 List of realms for SASL authentication mechanisms that need them.
16497 You can leave it empty if you don't want to support multiple realms.
16498 Many clients simply use the first one listed here, so keep the default
16500 Defaults to @samp{()}.
16503 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
16504 Default realm/domain to use if none was specified. This is used for
16505 both SASL realms and appending @@domain to username in plaintext
16507 Defaults to @samp{""}.
16510 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
16511 List of allowed characters in username. If the user-given username
16512 contains a character not listed in here, the login automatically fails.
16513 This is just an extra check to make sure user can't exploit any
16514 potential quote escaping vulnerabilities with SQL/LDAP databases. If
16515 you want to allow all characters, set this value to empty.
16516 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
16519 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
16520 Username character translations before it's looked up from
16521 databases. The value contains series of from -> to characters. For
16522 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
16523 translated to @samp{@@}.
16524 Defaults to @samp{""}.
16527 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
16528 Username formatting before it's looked up from databases. You can
16529 use the standard variables here, e.g.@: %Lu would lowercase the username,
16530 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
16531 change the @samp{@@} into @samp{-AT-}. This translation is done after
16532 @samp{auth-username-translation} changes.
16533 Defaults to @samp{"%Lu"}.
16536 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
16537 If you want to allow master users to log in by specifying the master
16538 username within the normal username string (i.e.@: not using SASL
16539 mechanism's support for it), you can specify the separator character
16540 here. The format is then <username><separator><master username>.
16541 UW-IMAP uses @samp{*} as the separator, so that could be a good
16543 Defaults to @samp{""}.
16546 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
16547 Username to use for users logging in with ANONYMOUS SASL
16549 Defaults to @samp{"anonymous"}.
16552 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
16553 Maximum number of dovecot-auth worker processes. They're used to
16554 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
16555 They're automatically created and destroyed as needed.
16556 Defaults to @samp{30}.
16559 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
16560 Host name to use in GSSAPI principal names. The default is to use
16561 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
16562 allow all keytab entries.
16563 Defaults to @samp{""}.
16566 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16567 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16568 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16569 need to change the auth service to run as root to be able to read this
16571 Defaults to @samp{""}.
16574 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16575 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16576 and @samp{ntlm-auth} helper.
16577 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16578 Defaults to @samp{#f}.
16581 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16582 Path for Samba's @samp{ntlm-auth} helper binary.
16583 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16586 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16587 Time to delay before replying to failed authentications.
16588 Defaults to @samp{"2 secs"}.
16591 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16592 Require a valid SSL client certificate or the authentication
16594 Defaults to @samp{#f}.
16597 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16598 Take the username from client's SSL certificate, using
16599 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16601 Defaults to @samp{#f}.
16604 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16605 List of wanted authentication mechanisms. Supported mechanisms are:
16606 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16607 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16608 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16609 @samp{disable-plaintext-auth} setting.
16612 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16613 List of IPs or hostnames to all director servers, including ourself.
16614 Ports can be specified as ip:port. The default port is the same as what
16615 director service's @samp{inet-listener} is using.
16616 Defaults to @samp{()}.
16619 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16620 List of IPs or hostnames to all backend mail servers. Ranges are
16621 allowed too, like 10.0.0.10-10.0.0.30.
16622 Defaults to @samp{()}.
16625 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16626 How long to redirect users to a specific server after it no longer
16627 has any connections.
16628 Defaults to @samp{"15 min"}.
16631 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16632 How the username is translated before being hashed. Useful values
16633 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16634 are shared within domain.
16635 Defaults to @samp{"%Lu"}.
16638 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16639 Log file to use for error messages. @samp{syslog} logs to syslog,
16640 @samp{/dev/stderr} logs to stderr.
16641 Defaults to @samp{"syslog"}.
16644 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16645 Log file to use for informational messages. Defaults to
16647 Defaults to @samp{""}.
16650 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16651 Log file to use for debug messages. Defaults to
16652 @samp{info-log-path}.
16653 Defaults to @samp{""}.
16656 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16657 Syslog facility to use if you're logging to syslog. Usually if you
16658 don't want to use @samp{mail}, you'll use local0..local7. Also other
16659 standard facilities are supported.
16660 Defaults to @samp{"mail"}.
16663 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16664 Log unsuccessful authentication attempts and the reasons why they
16666 Defaults to @samp{#f}.
16669 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16670 In case of password mismatches, log the attempted password. Valid
16671 values are no, plain and sha1. sha1 can be useful for detecting brute
16672 force password attempts vs. user simply trying the same password over
16673 and over again. You can also truncate the value to n chars by appending
16674 ":n" (e.g.@: sha1:6).
16675 Defaults to @samp{"no"}.
16678 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16679 Even more verbose logging for debugging purposes. Shows for example
16681 Defaults to @samp{#f}.
16684 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16685 In case of password mismatches, log the passwords and used scheme so
16686 the problem can be debugged. Enabling this also enables
16688 Defaults to @samp{#f}.
16691 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16692 Enable mail process debugging. This can help you figure out why
16693 Dovecot isn't finding your mails.
16694 Defaults to @samp{#f}.
16697 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16698 Show protocol level SSL errors.
16699 Defaults to @samp{#f}.
16702 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16703 Prefix for each line written to log file. % codes are in
16704 strftime(3) format.
16705 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16708 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16709 List of elements we want to log. The elements which have a
16710 non-empty variable value are joined together to form a comma-separated
16714 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16715 Login log format. %s contains @samp{login-log-format-elements}
16716 string, %$ contains the data we want to log.
16717 Defaults to @samp{"%$: %s"}.
16720 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16721 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16722 of possible variables you can use.
16723 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16726 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16727 Format to use for logging mail deliveries. You can use variables:
16730 Delivery status message (e.g.@: @samp{saved to INBOX})
16742 Defaults to @samp{"msgid=%m: %$"}.
16745 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16746 Location for users' mailboxes. The default is empty, which means
16747 that Dovecot tries to find the mailboxes automatically. This won't work
16748 if the user doesn't yet have any mail, so you should explicitly tell
16749 Dovecot the full location.
16751 If you're using mbox, giving a path to the INBOX
16752 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16753 where the other mailboxes are kept. This is called the "root mail
16754 directory", and it must be the first path given in the
16755 @samp{mail-location} setting.
16757 There are a few special variables you can use, eg.:
16763 user part in user@@domain, same as %u if there's no domain
16765 domain part in user@@domain, empty if there's no domain
16770 See doc/wiki/Variables.txt for full list. Some examples:
16772 @item maildir:~/Maildir
16773 @item mbox:~/mail:INBOX=/var/mail/%u
16774 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16776 Defaults to @samp{""}.
16779 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16780 System user and group used to access mails. If you use multiple,
16781 userdb can override these by returning uid or gid fields. You can use
16782 either numbers or names. <doc/wiki/UserIds.txt>.
16783 Defaults to @samp{""}.
16786 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16788 Defaults to @samp{""}.
16791 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16792 Group to enable temporarily for privileged operations. Currently
16793 this is used only with INBOX when either its initial creation or
16794 dotlocking fails. Typically this is set to "mail" to give access to
16796 Defaults to @samp{""}.
16799 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16800 Grant access to these supplementary groups for mail processes.
16801 Typically these are used to set up access to shared mailboxes. Note
16802 that it may be dangerous to set these if users can create
16803 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16804 could allow a user to delete others' mailboxes, or ln -s
16805 /secret/shared/box ~/mail/mybox would allow reading it).
16806 Defaults to @samp{""}.
16809 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16810 Allow full file system access to clients. There's no access checks
16811 other than what the operating system does for the active UID/GID. It
16812 works with both maildir and mboxes, allowing you to prefix mailboxes
16813 names with e.g.@: /path/ or ~user/.
16814 Defaults to @samp{#f}.
16817 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16818 Don't use mmap() at all. This is required if you store indexes to
16819 shared file systems (NFS or clustered file system).
16820 Defaults to @samp{#f}.
16823 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16824 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16825 supports @samp{O_EXCL} since version 3, so this should be safe to use
16826 nowadays by default.
16827 Defaults to @samp{#t}.
16830 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16831 When to use fsync() or fdatasync() calls:
16834 Whenever necessary to avoid losing important data
16836 Useful with e.g.@: NFS when write()s are delayed
16838 Never use it (best performance, but crashes can lose data).
16840 Defaults to @samp{"optimized"}.
16843 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16844 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16845 NFS caches whenever needed. If you're using only a single mail server
16847 Defaults to @samp{#f}.
16850 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16851 Mail index files also exist in NFS. Setting this to yes requires
16852 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16853 Defaults to @samp{#f}.
16856 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16857 Locking method for index files. Alternatives are fcntl, flock and
16858 dotlock. Dotlocking uses some tricks which may create more disk I/O
16859 than other locking methods. NFS users: flock doesn't work, remember to
16860 change @samp{mmap-disable}.
16861 Defaults to @samp{"fcntl"}.
16864 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16865 Directory in which LDA/LMTP temporarily stores incoming mails >128
16867 Defaults to @samp{"/tmp"}.
16870 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16871 Valid UID range for users. This is mostly to make sure that users can't
16872 log in as daemons or other system users. Note that denying root logins is
16873 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16875 Defaults to @samp{500}.
16878 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16880 Defaults to @samp{0}.
16883 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16884 Valid GID range for users. Users having non-valid GID as primary group ID
16885 aren't allowed to log in. If user belongs to supplementary groups with
16886 non-valid GIDs, those groups are not set.
16887 Defaults to @samp{1}.
16890 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16892 Defaults to @samp{0}.
16895 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16896 Maximum allowed length for mail keyword name. It's only forced when
16897 trying to create new keywords.
16898 Defaults to @samp{50}.
16901 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16902 List of directories under which chrooting is allowed for mail
16903 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16904 too). This setting doesn't affect @samp{login-chroot}
16905 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16906 "/./" in home dirs are ignored. WARNING: Never add directories here
16907 which local users can modify, that may lead to root exploit. Usually
16908 this should be done only if you don't allow shell access for users.
16909 <doc/wiki/Chrooting.txt>.
16910 Defaults to @samp{()}.
16913 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16914 Default chroot directory for mail processes. This can be overridden
16915 for specific users in user database by giving /./ in user's home
16916 directory (e.g.@: /home/./user chroots into /home). Note that usually
16917 there is no real need to do chrooting, Dovecot doesn't allow users to
16918 access files outside their mail directory anyway. If your home
16919 directories are prefixed with the chroot directory, append "/."@: to
16920 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16921 Defaults to @samp{""}.
16924 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16925 UNIX socket path to master authentication server to find users.
16926 This is used by imap (for shared users) and lda.
16927 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16930 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16931 Directory where to look up mail plugins.
16932 Defaults to @samp{"/usr/lib/dovecot"}.
16935 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16936 List of plugins to load for all services. Plugins specific to IMAP,
16937 LDA, etc.@: are added to this list in their own .conf files.
16938 Defaults to @samp{()}.
16941 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16942 The minimum number of mails in a mailbox before updates are done to
16943 cache file. This allows optimizing Dovecot's behavior to do less disk
16944 writes at the cost of more disk reads.
16945 Defaults to @samp{0}.
16948 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16949 When IDLE command is running, mailbox is checked once in a while to
16950 see if there are any new mails or other changes. This setting defines
16951 the minimum time to wait between those checks. Dovecot can also use
16952 dnotify, inotify and kqueue to find out immediately when changes
16954 Defaults to @samp{"30 secs"}.
16957 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16958 Save mails with CR+LF instead of plain LF. This makes sending those
16959 mails take less CPU, especially with sendfile() syscall with Linux and
16960 FreeBSD. But it also creates a bit more disk I/O which may just make it
16961 slower. Also note that if other software reads the mboxes/maildirs,
16962 they may handle the extra CRs wrong and cause problems.
16963 Defaults to @samp{#f}.
16966 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16967 By default LIST command returns all entries in maildir beginning
16968 with a dot. Enabling this option makes Dovecot return only entries
16969 which are directories. This is done by stat()ing each entry, so it
16970 causes more disk I/O.
16971 (For systems setting struct @samp{dirent->d_type} this check is free
16972 and it's done always regardless of this setting).
16973 Defaults to @samp{#f}.
16976 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16977 When copying a message, do it with hard links whenever possible.
16978 This makes the performance much better, and it's unlikely to have any
16980 Defaults to @samp{#t}.
16983 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16984 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16985 directory only when its mtime changes unexpectedly or when we can't find
16986 the mail otherwise.
16987 Defaults to @samp{#f}.
16990 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16991 Which locking methods to use for locking mbox. There are four
16996 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16997 solution. If you want to use /var/mail/ like directory, the users will
16998 need write access to that directory.
17000 Same as dotlock, but if it fails because of permissions or because there
17001 isn't enough disk space, just skip it.
17003 Use this if possible. Works with NFS too if lockd is used.
17005 May not exist in all systems. Doesn't work with NFS.
17007 May not exist in all systems. Doesn't work with NFS.
17010 You can use multiple locking methods; if you do the order they're declared
17011 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17012 locking methods as well. Some operating systems don't allow using some of
17013 them simultaneously.
17016 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17020 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17021 Maximum time to wait for lock (all of them) before aborting.
17022 Defaults to @samp{"5 mins"}.
17025 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17026 If dotlock exists but the mailbox isn't modified in any way,
17027 override the lock file after this much time.
17028 Defaults to @samp{"2 mins"}.
17031 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17032 When mbox changes unexpectedly we have to fully read it to find out
17033 what changed. If the mbox is large this can take a long time. Since
17034 the change is usually just a newly appended mail, it'd be faster to
17035 simply read the new mails. If this setting is enabled, Dovecot does
17036 this but still safely fallbacks to re-reading the whole mbox file
17037 whenever something in mbox isn't how it's expected to be. The only real
17038 downside to this setting is that if some other MUA changes message
17039 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17040 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17041 Defaults to @samp{#t}.
17044 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17045 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17046 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17047 @samp{mbox-dirty-syncs} is ignored.
17048 Defaults to @samp{#f}.
17051 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17052 Delay writing mbox headers until doing a full write sync (EXPUNGE
17053 and CHECK commands and when closing the mailbox). This is especially
17054 useful for POP3 where clients often delete all mails. The downside is
17055 that our changes aren't immediately visible to other MUAs.
17056 Defaults to @samp{#t}.
17059 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17060 If mbox size is smaller than this (e.g.@: 100k), don't write index
17061 files. If an index file already exists it's still read, just not
17063 Defaults to @samp{0}.
17066 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17067 Maximum dbox file size until it's rotated.
17068 Defaults to @samp{10000000}.
17071 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17072 Maximum dbox file age until it's rotated. Typically in days. Day
17073 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17075 Defaults to @samp{"1d"}.
17078 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17079 When creating new mdbox files, immediately preallocate their size to
17080 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17081 with some file systems (ext4, xfs).
17082 Defaults to @samp{#f}.
17085 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17086 sdbox and mdbox support saving mail attachments to external files,
17087 which also allows single instance storage for them. Other backends
17088 don't support this for now.
17090 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17092 Directory root where to store mail attachments. Disabled, if empty.
17093 Defaults to @samp{""}.
17096 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17097 Attachments smaller than this aren't saved externally. It's also
17098 possible to write a plugin to disable saving specific attachments
17100 Defaults to @samp{128000}.
17103 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17104 File system backend to use for saving attachments:
17107 No SiS done by Dovecot (but this might help FS's own deduplication)
17109 SiS with immediate byte-by-byte comparison during saving
17110 @item sis-queue posix
17111 SiS with delayed comparison and deduplication.
17113 Defaults to @samp{"sis posix"}.
17116 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17117 Hash format to use in attachment filenames. You can add any text and
17118 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17119 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17120 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17121 Defaults to @samp{"%@{sha1@}"}.
17124 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17126 Defaults to @samp{100}.
17129 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17131 Defaults to @samp{1000}.
17134 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17135 Default VSZ (virtual memory size) limit for service processes.
17136 This is mainly intended to catch and kill processes that leak memory
17137 before they eat up everything.
17138 Defaults to @samp{256000000}.
17141 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17142 Login user is internally used by login processes. This is the most
17143 untrusted user in Dovecot system. It shouldn't have access to anything
17145 Defaults to @samp{"dovenull"}.
17148 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17149 Internal user is used by unprivileged processes. It should be
17150 separate from login user, so that login processes can't disturb other
17152 Defaults to @samp{"dovecot"}.
17155 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17156 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17157 Defaults to @samp{"required"}.
17160 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17161 PEM encoded X.509 SSL/TLS certificate (public key).
17162 Defaults to @samp{"</etc/dovecot/default.pem"}.
17165 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17166 PEM encoded SSL/TLS private key. The key is opened before
17167 dropping root privileges, so keep the key file unreadable by anyone but
17169 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17172 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17173 If key file is password protected, give the password here.
17174 Alternatively give it when starting dovecot with -p parameter. Since
17175 this file is often world-readable, you may want to place this setting
17176 instead to a different.
17177 Defaults to @samp{""}.
17180 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17181 PEM encoded trusted certificate authority. Set this only if you
17182 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17183 contain the CA certificate(s) followed by the matching
17184 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17185 Defaults to @samp{""}.
17188 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17189 Require that CRL check succeeds for client certificates.
17190 Defaults to @samp{#t}.
17193 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17194 Request client to send a certificate. If you also want to require
17195 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17196 Defaults to @samp{#f}.
17199 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17200 Which field from certificate to use for username. commonName and
17201 x500UniqueIdentifier are the usual choices. You'll also need to set
17202 @samp{auth-ssl-username-from-cert? #t}.
17203 Defaults to @samp{"commonName"}.
17206 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17207 Minimum SSL protocol version to accept.
17208 Defaults to @samp{"TLSv1"}.
17211 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17212 SSL ciphers to use.
17213 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17216 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17217 SSL crypto device to use, for valid values run "openssl engine".
17218 Defaults to @samp{""}.
17221 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17222 Address to use when sending rejection mails.
17223 %d expands to recipient domain.
17224 Defaults to @samp{"postmaster@@%d"}.
17227 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17228 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17229 and in LMTP replies. Default is the system's real hostname@@domain.
17230 Defaults to @samp{""}.
17233 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17234 If user is over quota, return with temporary failure instead of
17236 Defaults to @samp{#f}.
17239 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17240 Binary to use for sending mails.
17241 Defaults to @samp{"/usr/sbin/sendmail"}.
17244 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17245 If non-empty, send mails via this SMTP host[:port] instead of
17247 Defaults to @samp{""}.
17250 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17251 Subject: header to use for rejection mails. You can use the same
17252 variables as for @samp{rejection-reason} below.
17253 Defaults to @samp{"Rejected: %s"}.
17256 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17257 Human readable error message for rejection mails. You can use
17270 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17273 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17274 Delimiter character between local-part and detail in email
17276 Defaults to @samp{"+"}.
17279 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17280 Header where the original recipient address (SMTP's RCPT TO:
17281 address) is taken from if not available elsewhere. With dovecot-lda -a
17282 parameter overrides this. A commonly used header for this is
17284 Defaults to @samp{""}.
17287 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17288 Should saving a mail to a nonexistent mailbox automatically create
17290 Defaults to @samp{#f}.
17293 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17294 Should automatically created mailboxes be also automatically
17296 Defaults to @samp{#f}.
17299 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17300 Maximum IMAP command line length. Some clients generate very long
17301 command lines with huge mailboxes, so you may need to raise this if you
17302 get "Too long argument" or "IMAP command line too large" errors
17304 Defaults to @samp{64000}.
17307 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17308 IMAP logout format string:
17311 total number of bytes read from client
17313 total number of bytes sent to client.
17315 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17316 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@}"}.
17319 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17320 Override the IMAP CAPABILITY response. If the value begins with '+',
17321 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17322 Defaults to @samp{""}.
17325 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17326 How long to wait between "OK Still here" notifications when client
17328 Defaults to @samp{"2 mins"}.
17331 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17332 ID field names and values to send to clients. Using * as the value
17333 makes Dovecot use the default value. The following fields have default
17334 values currently: name, version, os, os-version, support-url,
17336 Defaults to @samp{""}.
17339 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17340 ID fields sent by client to log. * means everything.
17341 Defaults to @samp{""}.
17344 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17345 Workarounds for various client bugs:
17348 @item delay-newmail
17349 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17350 CHECK commands. Some clients ignore them otherwise, for example OSX
17351 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17352 may show user "Message no longer in server" errors. Note that OE6
17353 still breaks even with this workaround if synchronization is set to
17356 @item tb-extra-mailbox-sep
17357 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17358 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17359 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17361 @item tb-lsub-flags
17362 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17363 This makes Thunderbird realize they aren't selectable and show them
17364 greyed out, instead of only later giving "not selectable" popup error.
17366 Defaults to @samp{()}.
17369 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17370 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17371 Defaults to @samp{""}.
17375 Whew! Lots of configuration options. The nice thing about it though is
17376 that Guix has a complete interface to Dovecot's configuration
17377 language. This allows not only a nice way to declare configurations,
17378 but also offers reflective capabilities as well: users can write code to
17379 inspect and transform configurations from within Scheme.
17381 However, it could be that you just want to get a @code{dovecot.conf} up
17382 and running. In that case, you can pass an
17383 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17384 @code{dovecot-service}. As its name indicates, an opaque configuration
17385 does not have easy reflective capabilities.
17387 Available @code{opaque-dovecot-configuration} fields are:
17389 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17390 The dovecot package.
17393 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17394 The contents of the @code{dovecot.conf}, as a string.
17397 For example, if your @code{dovecot.conf} is just the empty string, you
17398 could instantiate a dovecot service like this:
17401 (dovecot-service #:config
17402 (opaque-dovecot-configuration
17406 @subsubheading OpenSMTPD Service
17408 @deffn {Scheme Variable} opensmtpd-service-type
17409 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17410 service, whose value should be an @code{opensmtpd-configuration} object
17411 as in this example:
17414 (service opensmtpd-service-type
17415 (opensmtpd-configuration
17416 (config-file (local-file "./my-smtpd.conf"))))
17420 @deftp {Data Type} opensmtpd-configuration
17421 Data type representing the configuration of opensmtpd.
17424 @item @code{package} (default: @var{opensmtpd})
17425 Package object of the OpenSMTPD SMTP server.
17427 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17428 File-like object of the OpenSMTPD configuration file to use. By default
17429 it listens on the loopback network interface, and allows for mail from
17430 users and daemons on the local machine, as well as permitting email to
17431 remote servers. Run @command{man smtpd.conf} for more information.
17436 @subsubheading Exim Service
17438 @cindex mail transfer agent (MTA)
17439 @cindex MTA (mail transfer agent)
17442 @deffn {Scheme Variable} exim-service-type
17443 This is the type of the @uref{https://exim.org, Exim} mail transfer
17444 agent (MTA), whose value should be an @code{exim-configuration} object
17445 as in this example:
17448 (service exim-service-type
17449 (exim-configuration
17450 (config-file (local-file "./my-exim.conf"))))
17454 In order to use an @code{exim-service-type} service you must also have a
17455 @code{mail-aliases-service-type} service present in your
17456 @code{operating-system} (even if it has no aliases).
17458 @deftp {Data Type} exim-configuration
17459 Data type representing the configuration of exim.
17462 @item @code{package} (default: @var{exim})
17463 Package object of the Exim server.
17465 @item @code{config-file} (default: @code{#f})
17466 File-like object of the Exim configuration file to use. If its value is
17467 @code{#f} then use the default configuration file from the package
17468 provided in @code{package}. The resulting configuration file is loaded
17469 after setting the @code{exim_user} and @code{exim_group} configuration
17475 @subsubheading Getmail service
17480 @deffn {Scheme Variable} getmail-service-type
17481 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
17482 mail retriever, whose value should be an @code{getmail-configuration}.
17485 Available @code{getmail-configuration} fields are:
17487 @deftypevr {@code{getmail-configuration} parameter} symbol name
17488 A symbol to identify the getmail service.
17490 Defaults to @samp{"unset"}.
17494 @deftypevr {@code{getmail-configuration} parameter} package package
17495 The getmail package to use.
17499 @deftypevr {@code{getmail-configuration} parameter} string user
17500 The user to run getmail as.
17502 Defaults to @samp{"getmail"}.
17506 @deftypevr {@code{getmail-configuration} parameter} string group
17507 The group to run getmail as.
17509 Defaults to @samp{"getmail"}.
17513 @deftypevr {@code{getmail-configuration} parameter} string directory
17514 The getmail directory to use.
17516 Defaults to @samp{"/var/lib/getmail/default"}.
17520 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
17521 The getmail configuration file to use.
17523 Available @code{getmail-configuration-file} fields are:
17525 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
17526 What mail account to retrieve mail from, and how to access that account.
17528 Available @code{getmail-retriever-configuration} fields are:
17530 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
17531 The type of mail retriever to use. Valid values include @samp{passwd}
17534 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
17538 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
17539 Space separated list of arguments to the userdb driver.
17541 Defaults to @samp{unset}.
17545 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
17546 Space separated list of arguments to the userdb driver.
17548 Defaults to @samp{unset}.
17552 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
17553 Space separated list of arguments to the userdb driver.
17555 Defaults to @samp{#f}.
17559 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
17560 Override fields from passwd.
17562 Defaults to @samp{""}.
17566 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17567 Override fields from passwd.
17569 Defaults to @samp{()}.
17573 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17574 PEM-formatted key file to use for the TLS negotiation
17576 Defaults to @samp{""}.
17580 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17581 PEM-formatted certificate file to use for the TLS negotiation
17583 Defaults to @samp{""}.
17587 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17588 CA certificates to use
17590 Defaults to @samp{""}.
17594 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17595 Extra retriever parameters
17597 Defaults to @samp{()}.
17603 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17604 What to do with retrieved messages.
17606 Available @code{getmail-destination-configuration} fields are:
17608 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17609 The type of mail destination. Valid values include @samp{Maildir},
17610 @samp{Mboxrd} and @samp{MDA_external}.
17612 Defaults to @samp{unset}.
17616 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17617 The path option for the mail destination. The behaviour depends on the
17620 Defaults to @samp{""}.
17624 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17625 Extra destination parameters
17627 Defaults to @samp{()}.
17633 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17636 Available @code{getmail-options-configuration} fields are:
17638 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17639 If set to @samp{0}, getmail will only print warnings and errors. A
17640 value of @samp{1} means that messages will be printed about retrieving
17641 and deleting messages. If set to @samp{2}, getmail will print messages
17642 about each of it's actions.
17644 Defaults to @samp{1}.
17648 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17649 If true, getmail will retrieve all available messages. Otherwise it
17650 will only retrieve messages it hasn't seen previously.
17652 Defaults to @samp{#t}.
17656 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17657 If set to true, messages will be deleted from the server after
17658 retrieving and successfully delivering them. Otherwise, messages will
17659 be left on the server.
17661 Defaults to @samp{#f}.
17665 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17666 Getmail will delete messages this number of days after seeing them, if
17667 they have been delivered. This means messages will be left on the
17668 server this number of days after delivering them. A value of @samp{0}
17669 disabled this feature.
17671 Defaults to @samp{0}.
17675 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17676 Delete messages larger than this of bytes after retrieving them, even if
17677 the delete and delete-after options are disabled. A value of @samp{0}
17678 disables this feature.
17680 Defaults to @samp{0}.
17684 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17685 Retrieve messages totalling up to this number of bytes before closing
17686 the session with the server. A value of @samp{0} disables this feature.
17688 Defaults to @samp{0}.
17692 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17693 Don't retrieve messages larger than this number of bytes. A value of
17694 @samp{0} disables this feature.
17696 Defaults to @samp{0}.
17700 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17701 If true, getmail will add a Delivered-To header to messages.
17703 Defaults to @samp{#t}.
17707 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17708 If set, getmail adds a Received header to the messages.
17710 Defaults to @samp{#t}.
17714 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17715 Getmail will record a log of its actions to the named file. A value of
17716 @samp{""} disables this feature.
17718 Defaults to @samp{""}.
17722 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17723 If true, getmail will record a log of its actions using the system
17726 Defaults to @samp{#t}.
17730 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17731 If true, getmail will log information about messages not retrieved and
17732 the reason for not retrieving them, as well as starting and ending
17735 Defaults to @samp{#t}.
17739 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17740 Extra options to include.
17742 Defaults to @samp{()}.
17750 @deftypevr {@code{getmail-configuration} parameter} list idle
17751 A list of mailboxes that getmail should wait on the server for new mail
17752 notifications. This depends on the server supporting the IDLE
17755 Defaults to @samp{()}.
17759 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17760 Environment variables to set for getmail.
17762 Defaults to @samp{()}.
17766 @subsubheading Mail Aliases Service
17768 @cindex email aliases
17769 @cindex aliases, for email addresses
17771 @deffn {Scheme Variable} mail-aliases-service-type
17772 This is the type of the service which provides @code{/etc/aliases},
17773 specifying how to deliver mail to users on this system.
17776 (service mail-aliases-service-type
17777 '(("postmaster" "bob")
17778 ("bob" "bob@@example.com" "bob@@example2.com")))
17782 The configuration for a @code{mail-aliases-service-type} service is an
17783 association list denoting how to deliver mail that comes to this
17784 system. Each entry is of the form @code{(alias addresses ...)}, with
17785 @code{alias} specifying the local alias and @code{addresses} specifying
17786 where to deliver this user's mail.
17788 The aliases aren't required to exist as users on the local system. In
17789 the above example, there doesn't need to be a @code{postmaster} entry in
17790 the @code{operating-system}'s @code{user-accounts} in order to deliver
17791 the @code{postmaster} mail to @code{bob} (which subsequently would
17792 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17794 @subsubheading GNU Mailutils IMAP4 Daemon
17795 @cindex GNU Mailutils IMAP4 Daemon
17797 @deffn {Scheme Variable} imap4d-service-type
17798 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17799 mailutils, GNU Mailutils Manual}), whose value should be an
17800 @code{imap4d-configuration} object as in this example:
17803 (service imap4d-service-type
17804 (imap4d-configuration
17805 (config-file (local-file "imap4d.conf"))))
17809 @deftp {Data Type} imap4d-configuration
17810 Data type representing the configuration of @command{imap4d}.
17813 @item @code{package} (default: @code{mailutils})
17814 The package that provides @command{imap4d}.
17816 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17817 File-like object of the configuration file to use, by default it will listen
17818 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17819 Mailutils Manual}, for details.
17824 @node Messaging Services
17825 @subsection Messaging Services
17830 The @code{(gnu services messaging)} module provides Guix service
17831 definitions for messaging services: currently only Prosody is supported.
17833 @subsubheading Prosody Service
17835 @deffn {Scheme Variable} prosody-service-type
17836 This is the type for the @uref{https://prosody.im, Prosody XMPP
17837 communication server}. Its value must be a @code{prosody-configuration}
17838 record as in this example:
17841 (service prosody-service-type
17842 (prosody-configuration
17843 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17846 (int-component-configuration
17847 (hostname "conference.example.net")
17849 (mod-muc (mod-muc-configuration)))))
17852 (virtualhost-configuration
17853 (domain "example.net"))))))
17856 See below for details about @code{prosody-configuration}.
17860 By default, Prosody does not need much configuration. Only one
17861 @code{virtualhosts} field is needed: it specifies the domain you wish
17864 You can perform various sanity checks on the generated configuration
17865 with the @code{prosodyctl check} command.
17867 Prosodyctl will also help you to import certificates from the
17868 @code{letsencrypt} directory so that the @code{prosody} user can access
17869 them. See @url{https://prosody.im/doc/letsencrypt}.
17872 prosodyctl --root cert import /etc/letsencrypt/live
17875 The available configuration parameters follow. Each parameter
17876 definition is preceded by its type; for example, @samp{string-list foo}
17877 indicates that the @code{foo} parameter should be specified as a list of
17878 strings. Types starting with @code{maybe-} denote parameters that won't
17879 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
17881 There is also a way to specify the configuration as a string, if you
17882 have an old @code{prosody.cfg.lua} file that you want to port over from
17883 some other system; see the end for more details.
17885 The @code{file-object} type designates either a file-like object
17886 (@pxref{G-Expressions, file-like objects}) or a file name.
17888 @c The following documentation was initially generated by
17889 @c (generate-documentation) in (gnu services messaging). Manually maintained
17890 @c documentation is better, so we shouldn't hesitate to edit below as
17891 @c needed. However if the change you want to make to this documentation
17892 @c can be done in an automated way, it's probably easier to change
17893 @c (generate-documentation) than to make it below and have to deal with
17894 @c the churn as Prosody updates.
17896 Available @code{prosody-configuration} fields are:
17898 @deftypevr {@code{prosody-configuration} parameter} package prosody
17899 The Prosody package.
17902 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
17903 Location of the Prosody data storage directory. See
17904 @url{https://prosody.im/doc/configure}.
17905 Defaults to @samp{"/var/lib/prosody"}.
17908 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
17909 Additional plugin directories. They are searched in all the specified
17910 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
17911 Defaults to @samp{()}.
17914 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
17915 Every virtual host and component needs a certificate so that clients and
17916 servers can securely verify its identity. Prosody will automatically load
17917 certificates/keys from the directory specified here.
17918 Defaults to @samp{"/etc/prosody/certs"}.
17921 @deftypevr {@code{prosody-configuration} parameter} string-list admins
17922 This is a list of accounts that are admins for the server. Note that you
17923 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
17924 @url{https://prosody.im/doc/creating_accounts}.
17925 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
17926 Defaults to @samp{()}.
17929 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
17930 Enable use of libevent for better performance under high load. See
17931 @url{https://prosody.im/doc/libevent}.
17932 Defaults to @samp{#f}.
17935 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
17936 This is the list of modules Prosody will load on startup. It looks for
17937 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
17938 Documentation on modules can be found at:
17939 @url{https://prosody.im/doc/modules}.
17940 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
17943 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
17944 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
17945 should you want to disable them then add them to this list.
17946 Defaults to @samp{()}.
17949 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
17950 Path to a text file where the shared groups are defined. If this path is
17951 empty then @samp{mod_groups} does nothing. See
17952 @url{https://prosody.im/doc/modules/mod_groups}.
17953 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
17956 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
17957 Disable account creation by default, for security. See
17958 @url{https://prosody.im/doc/creating_accounts}.
17959 Defaults to @samp{#f}.
17962 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
17963 These are the SSL/TLS-related settings. Most of them are disabled so to
17964 use Prosody's defaults. If you do not completely understand these options, do
17965 not add them to your config, it is easy to lower the security of your server
17966 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
17968 Available @code{ssl-configuration} fields are:
17970 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
17971 This determines what handshake to use.
17974 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
17975 Path to your private key file.
17978 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
17979 Path to your certificate file.
17982 @deftypevr {@code{ssl-configuration} parameter} file-object capath
17983 Path to directory containing root certificates that you wish Prosody to
17984 trust when verifying the certificates of remote servers.
17985 Defaults to @samp{"/etc/ssl/certs"}.
17988 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
17989 Path to a file containing root certificates that you wish Prosody to trust.
17990 Similar to @code{capath} but with all certificates concatenated together.
17993 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
17994 A list of verification options (these mostly map to OpenSSL's
17995 @code{set_verify()} flags).
17998 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
17999 A list of general options relating to SSL/TLS. These map to OpenSSL's
18000 @code{set_options()}. For a full list of options available in LuaSec, see the
18004 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18005 How long a chain of certificate authorities to check when looking for a
18006 trusted root certificate.
18009 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18010 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18011 clients, and in what order.
18014 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18015 A path to a file containing parameters for Diffie-Hellman key exchange. You
18016 can create such a file with:
18017 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18020 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18021 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18022 @samp{"secp384r1"}.
18025 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18026 A list of "extra" verification options.
18029 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18030 Password for encrypted private keys.
18035 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18036 Whether to force all client-to-server connections to be encrypted or not.
18037 See @url{https://prosody.im/doc/modules/mod_tls}.
18038 Defaults to @samp{#f}.
18041 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18042 Set of mechanisms that will never be offered. See
18043 @url{https://prosody.im/doc/modules/mod_saslauth}.
18044 Defaults to @samp{("DIGEST-MD5")}.
18047 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18048 Whether to force all server-to-server connections to be encrypted or not.
18049 See @url{https://prosody.im/doc/modules/mod_tls}.
18050 Defaults to @samp{#f}.
18053 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18054 Whether to require encryption and certificate authentication. This
18055 provides ideal security, but requires servers you communicate with to support
18056 encryption AND present valid, trusted certificates. See
18057 @url{https://prosody.im/doc/s2s#security}.
18058 Defaults to @samp{#f}.
18061 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18062 Many servers don't support encryption or have invalid or self-signed
18063 certificates. You can list domains here that will not be required to
18064 authenticate using certificates. They will be authenticated using DNS. See
18065 @url{https://prosody.im/doc/s2s#security}.
18066 Defaults to @samp{()}.
18069 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18070 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18071 valid certificates for some domains by specifying a list here. See
18072 @url{https://prosody.im/doc/s2s#security}.
18073 Defaults to @samp{()}.
18076 @deftypevr {@code{prosody-configuration} parameter} string authentication
18077 Select the authentication backend to use. The default provider stores
18078 passwords in plaintext and uses Prosody's configured data storage to store the
18079 authentication data. If you do not trust your server please see
18080 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18081 about using the hashed backend. See also
18082 @url{https://prosody.im/doc/authentication}
18083 Defaults to @samp{"internal_plain"}.
18086 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18087 Set logging options. Advanced logging configuration is not yet supported
18088 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18089 Defaults to @samp{"*syslog"}.
18092 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18093 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18094 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18097 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18098 Maximum allowed size of the HTTP body (in bytes).
18101 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18102 Some modules expose their own URL in various ways. This URL is built
18103 from the protocol, host and port used. If Prosody sits behind a proxy, the
18104 public URL will be @code{http-external-url} instead. See
18105 @url{https://prosody.im/doc/http#external_url}.
18108 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18109 A host in Prosody is a domain on which user accounts can be created. For
18110 example if you want your users to have addresses like
18111 @samp{"john.smith@@example.com"} then you need to add a host
18112 @samp{"example.com"}. All options in this list will apply only to this host.
18114 Note: the name "virtual" host is used in configuration to avoid confusion with
18115 the actual physical host that Prosody is installed on. A single Prosody
18116 instance can serve many domains, each one defined as a VirtualHost entry in
18117 Prosody's configuration. Conversely a server that hosts a single domain would
18118 have just one VirtualHost entry.
18120 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18122 Available @code{virtualhost-configuration} fields are:
18124 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:
18125 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18126 Domain you wish Prosody to serve.
18131 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18132 Components are extra services on a server which are available to clients,
18133 usually on a subdomain of the main server (such as
18134 @samp{"mycomponent.example.com"}). Example components might be chatroom
18135 servers, user directories, or gateways to other protocols.
18137 Internal components are implemented with Prosody-specific plugins. To add an
18138 internal component, you simply fill the hostname field, and the plugin you wish
18139 to use for the component.
18141 See @url{https://prosody.im/doc/components}.
18142 Defaults to @samp{()}.
18144 Available @code{int-component-configuration} fields are:
18146 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:
18147 @deftypevr {@code{int-component-configuration} parameter} string hostname
18148 Hostname of the component.
18151 @deftypevr {@code{int-component-configuration} parameter} string plugin
18152 Plugin you wish to use for the component.
18155 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18156 Multi-user chat (MUC) is Prosody's module for allowing you to create
18157 hosted chatrooms/conferences for XMPP users.
18159 General information on setting up and using multi-user chatrooms can be found
18160 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
18161 which you should read if you are new to XMPP chatrooms.
18163 See also @url{https://prosody.im/doc/modules/mod_muc}.
18165 Available @code{mod-muc-configuration} fields are:
18167 @deftypevr {@code{mod-muc-configuration} parameter} string name
18168 The name to return in service discovery responses.
18169 Defaults to @samp{"Prosody Chatrooms"}.
18172 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18173 If @samp{#t}, this will only allow admins to create new chatrooms.
18174 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18175 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18176 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18177 restricts to service administrators only.
18178 Defaults to @samp{#f}.
18181 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18182 Maximum number of history messages that will be sent to the member that has
18183 just joined the room.
18184 Defaults to @samp{20}.
18191 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18192 External components use XEP-0114, which most standalone components
18193 support. To add an external component, you simply fill the hostname field. See
18194 @url{https://prosody.im/doc/components}.
18195 Defaults to @samp{()}.
18197 Available @code{ext-component-configuration} fields are:
18199 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:
18200 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18201 Password which the component will use to log in.
18204 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18205 Hostname of the component.
18210 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18211 Port(s) Prosody listens on for component connections.
18212 Defaults to @samp{(5347)}.
18215 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18216 Interface Prosody listens on for component connections.
18217 Defaults to @samp{"127.0.0.1"}.
18220 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18221 Raw content that will be added to the configuration file.
18224 It could be that you just want to get a @code{prosody.cfg.lua}
18225 up and running. In that case, you can pass an
18226 @code{opaque-prosody-configuration} record as the value of
18227 @code{prosody-service-type}. As its name indicates, an opaque configuration
18228 does not have easy reflective capabilities.
18229 Available @code{opaque-prosody-configuration} fields are:
18231 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18232 The prosody package.
18235 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18236 The contents of the @code{prosody.cfg.lua} to use.
18239 For example, if your @code{prosody.cfg.lua} is just the empty
18240 string, you could instantiate a prosody service like this:
18243 (service prosody-service-type
18244 (opaque-prosody-configuration
18245 (prosody.cfg.lua "")))
18248 @c end of Prosody auto-generated documentation
18250 @subsubheading BitlBee Service
18252 @cindex IRC (Internet Relay Chat)
18253 @cindex IRC gateway
18254 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18255 interface to a variety of messaging protocols such as XMPP.
18257 @defvr {Scheme Variable} bitlbee-service-type
18258 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18259 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18262 To have BitlBee listen on port 6667 on localhost, add this line to your
18266 (service bitlbee-service-type)
18270 @deftp {Data Type} bitlbee-configuration
18271 This is the configuration for BitlBee, with the following fields:
18274 @item @code{interface} (default: @code{"127.0.0.1"})
18275 @itemx @code{port} (default: @code{6667})
18276 Listen on the network interface corresponding to the IP address
18277 specified in @var{interface}, on @var{port}.
18279 When @var{interface} is @code{127.0.0.1}, only local clients can
18280 connect; when it is @code{0.0.0.0}, connections can come from any
18281 networking interface.
18283 @item @code{package} (default: @code{bitlbee})
18284 The BitlBee package to use.
18286 @item @code{plugins} (default: @code{'()})
18287 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18289 @item @code{extra-settings} (default: @code{""})
18290 Configuration snippet added as-is to the BitlBee configuration file.
18294 @subsubheading Quassel Service
18296 @cindex IRC (Internet Relay Chat)
18297 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18298 meaning that one or more clients can attach to and detach from the
18301 @defvr {Scheme Variable} quassel-service-type
18302 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18303 IRC backend daemon. Its value is a @code{quassel-configuration}
18307 @deftp {Data Type} quassel-configuration
18308 This is the configuration for Quassel, with the following fields:
18311 @item @code{quassel} (default: @code{quassel})
18312 The Quassel package to use.
18314 @item @code{interface} (default: @code{"::,0.0.0.0"})
18315 @item @code{port} (default: @code{4242})
18316 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18317 interfaces specified in the comma delimited @var{interface}, on
18320 @item @code{loglevel} (default: @code{"Info"})
18321 The level of logging desired. Accepted values are Debug, Info, Warning
18326 @node Telephony Services
18327 @subsection Telephony Services
18329 @cindex Murmur (VoIP server)
18330 @cindex VoIP server
18331 This section describes how to set up and run a Murmur server. Murmur is
18332 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18335 @deftp {Data Type} murmur-configuration
18336 The service type for the Murmur server. An example configuration can
18340 (service murmur-service-type
18341 (murmur-configuration
18343 "Welcome to this Mumble server running on Guix!")
18344 (cert-required? #t) ;disallow text password logins
18345 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18346 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18349 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18350 password with the command that is printed during the activation phase.
18352 It is recommended to register a normal Mumble user account
18353 and grant it admin or moderator rights.
18354 You can use the @code{mumble} client to
18355 login as new normal user, register yourself, and log out.
18356 For the next step login with the name @code{SuperUser} use
18357 the @code{SuperUser} password that you set previously,
18358 and grant your newly registered mumble user administrator or moderator
18359 rights and create some channels.
18361 Available @code{murmur-configuration} fields are:
18364 @item @code{package} (default: @code{mumble})
18365 Package that contains @code{bin/murmurd}.
18367 @item @code{user} (default: @code{"murmur"})
18368 User who will run the Murmur server.
18370 @item @code{group} (default: @code{"murmur"})
18371 Group of the user who will run the murmur server.
18373 @item @code{port} (default: @code{64738})
18374 Port on which the server will listen.
18376 @item @code{welcome-text} (default: @code{""})
18377 Welcome text sent to clients when they connect.
18379 @item @code{server-password} (default: @code{""})
18380 Password the clients have to enter in order to connect.
18382 @item @code{max-users} (default: @code{100})
18383 Maximum of users that can be connected to the server at once.
18385 @item @code{max-user-bandwidth} (default: @code{#f})
18386 Maximum voice traffic a user can send per second.
18388 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18389 File name of the sqlite database.
18390 The service's user will become the owner of the directory.
18392 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18393 File name of the log file.
18394 The service's user will become the owner of the directory.
18396 @item @code{autoban-attempts} (default: @code{10})
18397 Maximum number of logins a user can make in @code{autoban-timeframe}
18398 without getting auto banned for @code{autoban-time}.
18400 @item @code{autoban-timeframe} (default: @code{120})
18401 Timeframe for autoban in seconds.
18403 @item @code{autoban-time} (default: @code{300})
18404 Amount of time in seconds for which a client gets banned
18405 when violating the autoban limits.
18407 @item @code{opus-threshold} (default: @code{100})
18408 Percentage of clients that need to support opus
18409 before switching over to opus audio codec.
18411 @item @code{channel-nesting-limit} (default: @code{10})
18412 How deep channels can be nested at maximum.
18414 @item @code{channelname-regex} (default: @code{#f})
18415 A string in form of a Qt regular expression that channel names must conform to.
18417 @item @code{username-regex} (default: @code{#f})
18418 A string in form of a Qt regular expression that user names must conform to.
18420 @item @code{text-message-length} (default: @code{5000})
18421 Maximum size in bytes that a user can send in one text chat message.
18423 @item @code{image-message-length} (default: @code{(* 128 1024)})
18424 Maximum size in bytes that a user can send in one image message.
18426 @item @code{cert-required?} (default: @code{#f})
18427 If it is set to @code{#t} clients that use weak password authentication
18428 will not be accepted. Users must have completed the certificate wizard to join.
18430 @item @code{remember-channel?} (default: @code{#f})
18431 Should murmur remember the last channel each user was in when they disconnected
18432 and put them into the remembered channel when they rejoin.
18434 @item @code{allow-html?} (default: @code{#f})
18435 Should html be allowed in text messages, user comments, and channel descriptions.
18437 @item @code{allow-ping?} (default: @code{#f})
18438 Setting to true exposes the current user count, the maximum user count, and
18439 the server's maximum bandwidth per client to unauthenticated users. In the
18440 Mumble client, this information is shown in the Connect dialog.
18442 Disabling this setting will prevent public listing of the server.
18444 @item @code{bonjour?} (default: @code{#f})
18445 Should the server advertise itself in the local network through the bonjour protocol.
18447 @item @code{send-version?} (default: @code{#f})
18448 Should the murmur server version be exposed in ping requests.
18450 @item @code{log-days} (default: @code{31})
18451 Murmur also stores logs in the database, which are accessible via RPC.
18452 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
18453 or -1 to disable logging to the database.
18455 @item @code{obfuscate-ips?} (default: @code{#t})
18456 Should logged ips be obfuscated to protect the privacy of users.
18458 @item @code{ssl-cert} (default: @code{#f})
18459 File name of the SSL/TLS certificate used for encrypted connections.
18462 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
18464 @item @code{ssl-key} (default: @code{#f})
18465 Filepath to the ssl private key used for encrypted connections.
18467 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
18470 @item @code{ssl-dh-params} (default: @code{#f})
18471 File name of a PEM-encoded file with Diffie-Hellman parameters
18472 for the SSL/TLS encryption. Alternatively you set it to
18473 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
18474 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
18476 @item @code{ssl-ciphers} (default: @code{#f})
18477 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
18480 This option is specified using
18481 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
18482 OpenSSL cipher list notation}.
18484 It is recommended that you try your cipher string using 'openssl ciphers <string>'
18485 before setting it here, to get a feel for which cipher suites you will get.
18486 After setting this option, it is recommend that you inspect your Murmur log
18487 to ensure that Murmur is using the cipher suites that you expected it to.
18489 Note: Changing this option may impact the backwards compatibility of your
18490 Murmur server, and can remove the ability for older Mumble clients to be able
18493 @item @code{public-registration} (default: @code{#f})
18494 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
18496 You can optionally register your server in the public server list that the
18497 @code{mumble} client shows on startup.
18498 You cannot register your server if you have set a @code{server-password},
18499 or set @code{allow-ping} to @code{#f}.
18501 It might take a few hours until it shows up in the public list.
18503 @item @code{file} (default: @code{#f})
18504 Optional alternative override for this configuration.
18508 @deftp {Data Type} murmur-public-registration-configuration
18509 Configuration for public registration of a murmur service.
18513 This is a display name for your server. Not to be confused with the hostname.
18515 @item @code{password}
18516 A password to identify your registration.
18517 Subsequent updates will need the same password. Don't lose your password.
18520 This should be a @code{http://} or @code{https://} link to your web
18523 @item @code{hostname} (default: @code{#f})
18524 By default your server will be listed by its IP address.
18525 If it is set your server will be linked by this host name instead.
18531 @node Monitoring Services
18532 @subsection Monitoring Services
18534 @subsubheading Tailon Service
18536 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
18537 viewing and searching log files.
18539 The following example will configure the service with default values.
18540 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
18543 (service tailon-service-type)
18546 The following example customises more of the Tailon configuration,
18547 adding @command{sed} to the list of allowed commands.
18550 (service tailon-service-type
18551 (tailon-configuration
18553 (tailon-configuration-file
18554 (allowed-commands '("tail" "grep" "awk" "sed"))))))
18558 @deftp {Data Type} tailon-configuration
18559 Data type representing the configuration of Tailon.
18560 This type has the following parameters:
18563 @item @code{config-file} (default: @code{(tailon-configuration-file)})
18564 The configuration file to use for Tailon. This can be set to a
18565 @dfn{tailon-configuration-file} record value, or any gexp
18566 (@pxref{G-Expressions}).
18568 For example, to instead use a local file, the @code{local-file} function
18572 (service tailon-service-type
18573 (tailon-configuration
18574 (config-file (local-file "./my-tailon.conf"))))
18577 @item @code{package} (default: @code{tailon})
18578 The tailon package to use.
18583 @deftp {Data Type} tailon-configuration-file
18584 Data type representing the configuration options for Tailon.
18585 This type has the following parameters:
18588 @item @code{files} (default: @code{(list "/var/log")})
18589 List of files to display. The list can include strings for a single file
18590 or directory, or a list, where the first item is the name of a
18591 subsection, and the remaining items are the files or directories in that
18594 @item @code{bind} (default: @code{"localhost:8080"})
18595 Address and port to which Tailon should bind on.
18597 @item @code{relative-root} (default: @code{#f})
18598 URL path to use for Tailon, set to @code{#f} to not use a path.
18600 @item @code{allow-transfers?} (default: @code{#t})
18601 Allow downloading the log files in the web interface.
18603 @item @code{follow-names?} (default: @code{#t})
18604 Allow tailing of not-yet existent files.
18606 @item @code{tail-lines} (default: @code{200})
18607 Number of lines to read initially from each file.
18609 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18610 Commands to allow running. By default, @code{sed} is disabled.
18612 @item @code{debug?} (default: @code{#f})
18613 Set @code{debug?} to @code{#t} to show debug messages.
18615 @item @code{wrap-lines} (default: @code{#t})
18616 Initial line wrapping state in the web interface. Set to @code{#t} to
18617 initially wrap lines (the default), or to @code{#f} to initially not
18620 @item @code{http-auth} (default: @code{#f})
18621 HTTP authentication type to use. Set to @code{#f} to disable
18622 authentication (the default). Supported values are @code{"digest"} or
18625 @item @code{users} (default: @code{#f})
18626 If HTTP authentication is enabled (see @code{http-auth}), access will be
18627 restricted to the credentials provided here. To configure users, use a
18628 list of pairs, where the first element of the pair is the username, and
18629 the 2nd element of the pair is the password.
18632 (tailon-configuration-file
18633 (http-auth "basic")
18634 (users '(("user1" . "password1")
18635 ("user2" . "password2"))))
18642 @subsubheading Darkstat Service
18644 Darkstat is a packet sniffer that captures network traffic, calculates
18645 statistics about usage, and serves reports over HTTP.
18647 @defvar {Scheme Variable} darkstat-service-type
18648 This is the service type for the
18649 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18650 service, its value must be a @code{darkstat-configuration} record as in
18654 (service darkstat-service-type
18655 (darkstat-configuration
18656 (interface "eno1")))
18660 @deftp {Data Type} darkstat-configuration
18661 Data type representing the configuration of @command{darkstat}.
18664 @item @code{package} (default: @code{darkstat})
18665 The darkstat package to use.
18667 @item @code{interface}
18668 Capture traffic on the specified network interface.
18670 @item @code{port} (default: @code{"667"})
18671 Bind the web interface to the specified port.
18673 @item @code{bind-address} (default: @code{"127.0.0.1"})
18674 Bind the web interface to the specified address.
18676 @item @code{base} (default: @code{"/"})
18677 Specify the path of the base URL. This can be useful if
18678 @command{darkstat} is accessed via a reverse proxy.
18683 @subsubheading Prometheus Node Exporter Service
18685 @cindex prometheus-node-exporter
18686 The Prometheus ``node exporter'' makes hardware and operating system statistics
18687 provided by the Linux kernel available for the Prometheus monitoring system.
18688 This service should be deployed on all physical nodes and virtual machines,
18689 where monitoring these statistics is desirable.
18691 @defvar {Scheme variable} prometheus-node-exporter-service-type
18692 This is the service type for the
18693 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18694 service, its value must be a @code{prometheus-node-exporter-configuration}
18695 record as in this example:
18698 (service prometheus-node-exporter-service-type
18699 (prometheus-node-exporter-configuration
18700 (web-listen-address ":9100")))
18704 @deftp {Data Type} prometheus-node-exporter-configuration
18705 Data type representing the configuration of @command{node_exporter}.
18708 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18709 The prometheus-node-exporter package to use.
18711 @item @code{web-listen-address} (default: @code{":9100"})
18712 Bind the web interface to the specified address.
18717 @subsubheading Zabbix server
18718 @cindex zabbix zabbix-server
18719 Zabbix provides monitoring metrics, among others network utilization, CPU load
18720 and disk space consumption:
18723 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18724 @item Auto-discovery of servers and network devices and interfaces.
18725 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18726 @item Distributed monitoring with centralized web administration.
18727 @item Native high performance agents.
18728 @item SLA, and ITIL KPI metrics on reporting.
18729 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18730 @item Remote command execution through Zabbix proxies.
18733 @c %start of fragment
18735 Available @code{zabbix-server-configuration} fields are:
18737 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18738 The zabbix-server package.
18742 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18743 User who will run the Zabbix server.
18745 Defaults to @samp{"zabbix"}.
18749 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18750 Group who will run the Zabbix server.
18752 Defaults to @samp{"zabbix"}.
18756 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18757 Database host name.
18759 Defaults to @samp{"127.0.0.1"}.
18763 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18766 Defaults to @samp{"zabbix"}.
18770 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18773 Defaults to @samp{"zabbix"}.
18777 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18778 Database password. Please, use @code{include-files} with
18779 @code{DBPassword=SECRET} inside a specified file instead.
18781 Defaults to @samp{""}.
18785 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18788 Defaults to @samp{5432}.
18792 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18793 Specifies where log messages are written to:
18797 @code{system} - syslog.
18800 @code{file} - file specified with @code{log-file} parameter.
18803 @code{console} - standard output.
18807 Defaults to @samp{""}.
18811 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18812 Log file name for @code{log-type} @code{file} parameter.
18814 Defaults to @samp{"/var/log/zabbix/server.log"}.
18818 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18821 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18825 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18826 The location of certificate authority (CA) files for SSL server
18827 certificate verification.
18829 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18833 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18834 Location of SSL client certificates.
18836 Defaults to @samp{"/etc/ssl/certs"}.
18840 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18841 Extra options will be appended to Zabbix server configuration file.
18843 Defaults to @samp{""}.
18847 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18848 You may include individual files or all files in a directory in the
18849 configuration file.
18851 Defaults to @samp{()}.
18855 @c %end of fragment
18857 @subsubheading Zabbix agent
18858 @cindex zabbix zabbix-agent
18860 Zabbix agent gathers information for Zabbix server.
18862 @c %start of fragment
18864 Available @code{zabbix-agent-configuration} fields are:
18866 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
18867 The zabbix-agent package.
18871 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
18872 User who will run the Zabbix agent.
18874 Defaults to @samp{"zabbix"}.
18878 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
18879 Group who will run the Zabbix agent.
18881 Defaults to @samp{"zabbix"}.
18885 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
18886 Unique, case sensitive hostname which is required for active checks and
18887 must match hostname as configured on the server.
18889 Defaults to @samp{"Zabbix server"}.
18893 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
18894 Specifies where log messages are written to:
18898 @code{system} - syslog.
18901 @code{file} - file specified with @code{log-file} parameter.
18904 @code{console} - standard output.
18908 Defaults to @samp{""}.
18912 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
18913 Log file name for @code{log-type} @code{file} parameter.
18915 Defaults to @samp{"/var/log/zabbix/agent.log"}.
18919 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
18922 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
18926 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
18927 List of IP addresses, optionally in CIDR notation, or hostnames of
18928 Zabbix servers and Zabbix proxies. Incoming connections will be
18929 accepted only from the hosts listed here.
18931 Defaults to @samp{("127.0.0.1")}.
18935 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
18936 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
18937 proxies for active checks. If port is not specified, default port is
18938 used. If this parameter is not specified, active checks are disabled.
18940 Defaults to @samp{("127.0.0.1")}.
18944 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
18945 Extra options will be appended to Zabbix server configuration file.
18947 Defaults to @samp{""}.
18951 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
18952 You may include individual files or all files in a directory in the
18953 configuration file.
18955 Defaults to @samp{()}.
18959 @c %end of fragment
18961 @subsubheading Zabbix front-end
18962 @cindex zabbix zabbix-front-end
18964 This service provides a WEB interface to Zabbix server.
18966 @c %start of fragment
18968 Available @code{zabbix-front-end-configuration} fields are:
18970 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
18971 NGINX configuration.
18975 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
18976 Database host name.
18978 Defaults to @samp{"localhost"}.
18982 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
18985 Defaults to @samp{5432}.
18989 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
18992 Defaults to @samp{"zabbix"}.
18996 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
18999 Defaults to @samp{"zabbix"}.
19003 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19004 Database password. Please, use @code{db-secret-file} instead.
19006 Defaults to @samp{""}.
19010 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19011 Secret file which will be appended to @file{zabbix.conf.php} file. This
19012 file contains credentials for use by Zabbix front-end. You are expected
19013 to create it manually.
19015 Defaults to @samp{""}.
19019 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19020 Zabbix server hostname.
19022 Defaults to @samp{"localhost"}.
19026 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19027 Zabbix server port.
19029 Defaults to @samp{10051}.
19034 @c %end of fragment
19036 @node Kerberos Services
19037 @subsection Kerberos Services
19040 The @code{(gnu services kerberos)} module provides services relating to
19041 the authentication protocol @dfn{Kerberos}.
19043 @subsubheading Krb5 Service
19045 Programs using a Kerberos client library normally
19046 expect a configuration file in @file{/etc/krb5.conf}.
19047 This service generates such a file from a definition provided in the
19048 operating system declaration.
19049 It does not cause any daemon to be started.
19051 No ``keytab'' files are provided by this service---you must explicitly create them.
19052 This service is known to work with the MIT client library, @code{mit-krb5}.
19053 Other implementations have not been tested.
19055 @defvr {Scheme Variable} krb5-service-type
19056 A service type for Kerberos 5 clients.
19060 Here is an example of its use:
19062 (service krb5-service-type
19063 (krb5-configuration
19064 (default-realm "EXAMPLE.COM")
19065 (allow-weak-crypto? #t)
19068 (name "EXAMPLE.COM")
19069 (admin-server "groucho.example.com")
19070 (kdc "karl.example.com"))
19073 (admin-server "kerb-admin.argrx.edu")
19074 (kdc "keys.argrx.edu"))))))
19078 This example provides a Kerberos@tie{}5 client configuration which:
19080 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19081 of which have distinct administration servers and key distribution centers;
19082 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19083 specified by clients;
19084 @item Accepts services which only support encryption types known to be weak.
19087 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19088 Only the most commonly used ones are described here.
19089 For a full list, and more detailed explanation of each, see the MIT
19090 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19094 @deftp {Data Type} krb5-realm
19095 @cindex realm, kerberos
19098 This field is a string identifying the name of the realm.
19099 A common convention is to use the fully qualified DNS name of your organization,
19100 converted to upper case.
19102 @item @code{admin-server}
19103 This field is a string identifying the host where the administration server is
19107 This field is a string identifying the key distribution center
19112 @deftp {Data Type} krb5-configuration
19115 @item @code{allow-weak-crypto?} (default: @code{#f})
19116 If this flag is @code{#t} then services which only offer encryption algorithms
19117 known to be weak will be accepted.
19119 @item @code{default-realm} (default: @code{#f})
19120 This field should be a string identifying the default Kerberos
19121 realm for the client.
19122 You should set this field to the name of your Kerberos realm.
19123 If this value is @code{#f}
19124 then a realm must be specified with every Kerberos principal when invoking programs
19125 such as @command{kinit}.
19127 @item @code{realms}
19128 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19130 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19136 @subsubheading PAM krb5 Service
19139 The @code{pam-krb5} service allows for login authentication and password
19140 management via Kerberos.
19141 You will need this service if you want PAM enabled applications to authenticate
19142 users using Kerberos.
19144 @defvr {Scheme Variable} pam-krb5-service-type
19145 A service type for the Kerberos 5 PAM module.
19148 @deftp {Data Type} pam-krb5-configuration
19149 Data type representing the configuration of the Kerberos 5 PAM module.
19150 This type has the following parameters:
19152 @item @code{pam-krb5} (default: @code{pam-krb5})
19153 The pam-krb5 package to use.
19155 @item @code{minimum-uid} (default: @code{1000})
19156 The smallest user ID for which Kerberos authentications should be attempted.
19157 Local accounts with lower values will silently fail to authenticate.
19162 @node LDAP Services
19163 @subsection LDAP Services
19165 @cindex nslcd, LDAP service
19167 The @code{(gnu services authentication)} module provides the
19168 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19169 server. In addition to configuring the service itself, you may want to add
19170 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19171 Switch} for detailed information.
19173 Here is a simple operating system declaration with a default configuration of
19174 the @code{nslcd-service-type} and a Name Service Switch configuration that
19175 consults the @code{ldap} name service last:
19178 (use-service-modules authentication)
19179 (use-modules (gnu system nss))
19185 (service nslcd-service-type)
19186 (service dhcp-client-service-type)
19188 (name-service-switch
19189 (let ((services (list (name-service (name "db"))
19190 (name-service (name "files"))
19191 (name-service (name "ldap")))))
19192 (name-service-switch
19193 (inherit %mdns-host-lookup-nss)
19194 (password services)
19197 (netgroup services)
19198 (gshadow services)))))
19201 @c %start of generated documentation for nslcd-configuration
19203 Available @code{nslcd-configuration} fields are:
19205 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19206 The @code{nss-pam-ldapd} package to use.
19210 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19211 The number of threads to start that can handle requests and perform LDAP
19212 queries. Each thread opens a separate connection to the LDAP server.
19213 The default is to start 5 threads.
19215 Defaults to @samp{disabled}.
19219 @deftypevr {@code{nslcd-configuration} parameter} string uid
19220 This specifies the user id with which the daemon should be run.
19222 Defaults to @samp{"nslcd"}.
19226 @deftypevr {@code{nslcd-configuration} parameter} string gid
19227 This specifies the group id with which the daemon should be run.
19229 Defaults to @samp{"nslcd"}.
19233 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19234 This option controls the way logging is done via a list containing
19235 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
19236 or "syslog", or an absolute file name. The LEVEL argument is optional
19237 and specifies the log level. The log level may be one of the following
19238 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
19239 messages with the specified log level or higher are logged.
19241 Defaults to @samp{("/var/log/nslcd" info)}.
19245 @deftypevr {@code{nslcd-configuration} parameter} list uri
19246 The list of LDAP server URIs. Normally, only the first server will be
19247 used with the following servers as fall-back.
19249 Defaults to @samp{("ldap://localhost:389/")}.
19253 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19254 The version of the LDAP protocol to use. The default is to use the
19255 maximum version supported by the LDAP library.
19257 Defaults to @samp{disabled}.
19261 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19262 Specifies the distinguished name with which to bind to the directory
19263 server for lookups. The default is to bind anonymously.
19265 Defaults to @samp{disabled}.
19269 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19270 Specifies the credentials with which to bind. This option is only
19271 applicable when used with binddn.
19273 Defaults to @samp{disabled}.
19277 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19278 Specifies the distinguished name to use when the root user tries to
19279 modify a user's password using the PAM module.
19281 Defaults to @samp{disabled}.
19285 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19286 Specifies the credentials with which to bind if the root user tries to
19287 change a user's password. This option is only applicable when used with
19290 Defaults to @samp{disabled}.
19294 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19295 Specifies the SASL mechanism to be used when performing SASL
19298 Defaults to @samp{disabled}.
19302 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19303 Specifies the SASL realm to be used when performing SASL authentication.
19305 Defaults to @samp{disabled}.
19309 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19310 Specifies the authentication identity to be used when performing SASL
19313 Defaults to @samp{disabled}.
19317 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19318 Specifies the authorization identity to be used when performing SASL
19321 Defaults to @samp{disabled}.
19325 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19326 Determines whether the LDAP server host name should be canonicalised. If
19327 this is enabled the LDAP library will do a reverse host name lookup. By
19328 default, it is left up to the LDAP library whether this check is
19331 Defaults to @samp{disabled}.
19335 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19336 Set the name for the GSS-API Kerberos credentials cache.
19338 Defaults to @samp{disabled}.
19342 @deftypevr {@code{nslcd-configuration} parameter} string base
19343 The directory search base.
19345 Defaults to @samp{"dc=example,dc=com"}.
19349 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19350 Specifies the search scope (subtree, onelevel, base or children). The
19351 default scope is subtree; base scope is almost never useful for name
19352 service lookups; children scope is not supported on all servers.
19354 Defaults to @samp{(subtree)}.
19358 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19359 Specifies the policy for dereferencing aliases. The default policy is
19360 to never dereference aliases.
19362 Defaults to @samp{disabled}.
19366 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19367 Specifies whether automatic referral chasing should be enabled. The
19368 default behaviour is to chase referrals.
19370 Defaults to @samp{disabled}.
19374 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19375 This option allows for custom attributes to be looked up instead of the
19376 default RFC 2307 attributes. It is a list of maps, each consisting of
19377 the name of a map, the RFC 2307 attribute to match and the query
19378 expression for the attribute as it is available in the directory.
19380 Defaults to @samp{()}.
19384 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19385 A list of filters consisting of the name of a map to which the filter
19386 applies and an LDAP search filter expression.
19388 Defaults to @samp{()}.
19392 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19393 Specifies the time limit in seconds to use when connecting to the
19394 directory server. The default value is 10 seconds.
19396 Defaults to @samp{disabled}.
19400 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19401 Specifies the time limit (in seconds) to wait for a response from the
19402 LDAP server. A value of zero, which is the default, is to wait
19403 indefinitely for searches to be completed.
19405 Defaults to @samp{disabled}.
19409 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19410 Specifies the period if inactivity (in seconds) after which the con‐
19411 nection to the LDAP server will be closed. The default is not to time
19414 Defaults to @samp{disabled}.
19418 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19419 Specifies the number of seconds to sleep when connecting to all LDAP
19420 servers fails. By default one second is waited between the first
19421 failure and the first retry.
19423 Defaults to @samp{disabled}.
19427 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19428 Specifies the time after which the LDAP server is considered to be
19429 permanently unavailable. Once this time is reached retries will be done
19430 only once per this time period. The default value is 10 seconds.
19432 Defaults to @samp{disabled}.
19436 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
19437 Specifies whether to use SSL/TLS or not (the default is not to). If
19438 'start-tls is specified then StartTLS is used rather than raw LDAP over
19441 Defaults to @samp{disabled}.
19445 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
19446 Specifies what checks to perform on a server-supplied certificate. The
19447 meaning of the values is described in the ldap.conf(5) manual page.
19449 Defaults to @samp{disabled}.
19453 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
19454 Specifies the directory containing X.509 certificates for peer authen‐
19455 tication. This parameter is ignored when using GnuTLS.
19457 Defaults to @samp{disabled}.
19461 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
19462 Specifies the path to the X.509 certificate for peer authentication.
19464 Defaults to @samp{disabled}.
19468 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
19469 Specifies the path to an entropy source. This parameter is ignored when
19472 Defaults to @samp{disabled}.
19476 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
19477 Specifies the ciphers to use for TLS as a string.
19479 Defaults to @samp{disabled}.
19483 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
19484 Specifies the path to the file containing the local certificate for
19485 client TLS authentication.
19487 Defaults to @samp{disabled}.
19491 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
19492 Specifies the path to the file containing the private key for client TLS
19495 Defaults to @samp{disabled}.
19499 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
19500 Set this to a number greater than 0 to request paged results from the
19501 LDAP server in accordance with RFC2696. The default (0) is to not
19502 request paged results.
19504 Defaults to @samp{disabled}.
19508 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
19509 This option prevents group membership lookups through LDAP for the
19510 specified users. Alternatively, the value 'all-local may be used. With
19511 that value nslcd builds a full list of non-LDAP users on startup.
19513 Defaults to @samp{disabled}.
19517 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
19518 This option ensures that LDAP users with a numeric user id lower than
19519 the specified value are ignored.
19521 Defaults to @samp{disabled}.
19525 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
19526 This option specifies an offset that is added to all LDAP numeric user
19527 ids. This can be used to avoid user id collisions with local users.
19529 Defaults to @samp{disabled}.
19533 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
19534 This option specifies an offset that is added to all LDAP numeric group
19535 ids. This can be used to avoid user id collisions with local groups.
19537 Defaults to @samp{disabled}.
19541 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
19542 If this option is set, the member attribute of a group may point to
19543 another group. Members of nested groups are also returned in the higher
19544 level group and parent groups are returned when finding groups for a
19545 specific user. The default is not to perform extra searches for nested
19548 Defaults to @samp{disabled}.
19552 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
19553 If this option is set, the group member list is not retrieved when
19554 looking up groups. Lookups for finding which groups a user belongs to
19555 will remain functional so the user will likely still get the correct
19556 groups assigned on login.
19558 Defaults to @samp{disabled}.
19562 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
19563 If this option is set, functions which cause all user/group entries to
19564 be loaded from the directory will not succeed in doing so. This can
19565 dramatically reduce LDAP server load in situations where there are a
19566 great number of users and/or groups. This option is not recommended for
19567 most configurations.
19569 Defaults to @samp{disabled}.
19573 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19574 This option can be used to specify how user and group names are verified
19575 within the system. This pattern is used to check all user and group
19576 names that are requested and returned from LDAP.
19578 Defaults to @samp{disabled}.
19582 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19583 This specifies whether or not to perform searches using case-insensitive
19584 matching. Enabling this could open up the system to authorization
19585 bypass vulnerabilities and introduce nscd cache poisoning
19586 vulnerabilities which allow denial of service.
19588 Defaults to @samp{disabled}.
19592 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19593 This option specifies whether password policy controls are requested and
19594 handled from the LDAP server when performing user authentication.
19596 Defaults to @samp{disabled}.
19600 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19601 By default nslcd performs an LDAP search with the user's credentials
19602 after BIND (authentication) to ensure that the BIND operation was
19603 successful. The default search is a simple check to see if the user's
19604 DN exists. A search filter can be specified that will be used instead.
19605 It should return at least one entry.
19607 Defaults to @samp{disabled}.
19611 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19612 This option allows flexible fine tuning of the authorisation check that
19613 should be performed. The search filter specified is executed and if any
19614 entries match, access is granted, otherwise access is denied.
19616 Defaults to @samp{disabled}.
19620 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19621 If this option is set password modification using pam_ldap will be
19622 denied and the specified message will be presented to the user instead.
19623 The message can be used to direct the user to an alternative means of
19624 changing their password.
19626 Defaults to @samp{disabled}.
19630 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19631 List of pam service names for which LDAP authentication should suffice.
19633 Defaults to @samp{()}.
19637 @c %end of generated documentation for nslcd-configuration
19641 @subsection Web Services
19646 The @code{(gnu services web)} module provides the Apache HTTP Server,
19647 the nginx web server, and also a fastcgi wrapper daemon.
19649 @subsubheading Apache HTTP Server
19651 @deffn {Scheme Variable} httpd-service-type
19652 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19653 (@dfn{httpd}). The value for this service type is a
19654 @code{httpd-configuration} record.
19656 A simple example configuration is given below.
19659 (service httpd-service-type
19660 (httpd-configuration
19663 (server-name "www.example.com")
19664 (document-root "/srv/http/www.example.com")))))
19667 Other services can also extend the @code{httpd-service-type} to add to
19671 (simple-service 'www.example.com-server httpd-service-type
19675 (list (string-join '("ServerName www.example.com"
19676 "DocumentRoot /srv/http/www.example.com")
19681 The details for the @code{httpd-configuration}, @code{httpd-module},
19682 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19685 @deffn {Data Type} httpd-configuration
19686 This data type represents the configuration for the httpd service.
19689 @item @code{package} (default: @code{httpd})
19690 The httpd package to use.
19692 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19693 The pid file used by the shepherd-service.
19695 @item @code{config} (default: @code{(httpd-config-file)})
19696 The configuration file to use with the httpd service. The default value
19697 is a @code{httpd-config-file} record, but this can also be a different
19698 G-expression that generates a file, for example a @code{plain-file}. A
19699 file outside of the store can also be specified through a string.
19704 @deffn {Data Type} httpd-module
19705 This data type represents a module for the httpd service.
19709 The name of the module.
19712 The file for the module. This can be relative to the httpd package being
19713 used, the absolute location of a file, or a G-expression for a file
19714 within the store, for example @code{(file-append mod-wsgi
19715 "/modules/mod_wsgi.so")}.
19720 @defvr {Scheme Variable} %default-httpd-modules
19721 A default list of @code{httpd-module} objects.
19724 @deffn {Data Type} httpd-config-file
19725 This data type represents a configuration file for the httpd service.
19728 @item @code{modules} (default: @code{%default-httpd-modules})
19729 The modules to load. Additional modules can be added here, or loaded by
19730 additional configuration.
19732 For example, in order to handle requests for PHP files, you can use Apache’s
19733 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19736 (service httpd-service-type
19737 (httpd-configuration
19742 (name "proxy_module")
19743 (file "modules/mod_proxy.so"))
19745 (name "proxy_fcgi_module")
19746 (file "modules/mod_proxy_fcgi.so"))
19747 %default-httpd-modules))
19748 (extra-config (list "\
19749 <FilesMatch \\.php$>
19750 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19751 </FilesMatch>"))))))
19752 (service php-fpm-service-type
19753 (php-fpm-configuration
19754 (socket "/var/run/php-fpm.sock")
19755 (socket-group "httpd")))
19758 @item @code{server-root} (default: @code{httpd})
19759 The @code{ServerRoot} in the configuration file, defaults to the httpd
19760 package. Directives including @code{Include} and @code{LoadModule} are
19761 taken as relative to the server root.
19763 @item @code{server-name} (default: @code{#f})
19764 The @code{ServerName} in the configuration file, used to specify the
19765 request scheme, hostname and port that the server uses to identify
19768 This doesn't need to be set in the server config, and can be specifyed
19769 in virtual hosts. The default is @code{#f} to not specify a
19772 @item @code{document-root} (default: @code{"/srv/http"})
19773 The @code{DocumentRoot} from which files will be served.
19775 @item @code{listen} (default: @code{'("80")})
19776 The list of values for the @code{Listen} directives in the config
19777 file. The value should be a list of strings, when each string can
19778 specify the port number to listen on, and optionally the IP address and
19781 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19782 The @code{PidFile} to use. This should match the @code{pid-file} set in
19783 the @code{httpd-configuration} so that the Shepherd service is
19784 configured correctly.
19786 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19787 The @code{ErrorLog} to which the server will log errors.
19789 @item @code{user} (default: @code{"httpd"})
19790 The @code{User} which the server will answer requests as.
19792 @item @code{group} (default: @code{"httpd"})
19793 The @code{Group} which the server will answer requests as.
19795 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19796 A flat list of strings and G-expressions which will be added to the end
19797 of the configuration file.
19799 Any values which the service is extended with will be appended to this
19805 @deffn {Data Type} httpd-virtualhost
19806 This data type represents a virtualhost configuration block for the httpd service.
19808 These should be added to the extra-config for the httpd-service.
19811 (simple-service 'www.example.com-server httpd-service-type
19815 (list (string-join '("ServerName www.example.com"
19816 "DocumentRoot /srv/http/www.example.com")
19821 @item @code{addresses-and-ports}
19822 The addresses and ports for the @code{VirtualHost} directive.
19824 @item @code{contents}
19825 The contents of the @code{VirtualHost} directive, this should be a list
19826 of strings and G-expressions.
19831 @subsubheading NGINX
19833 @deffn {Scheme Variable} nginx-service-type
19834 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19835 value for this service type is a @code{<nginx-configuration>} record.
19837 A simple example configuration is given below.
19840 (service nginx-service-type
19841 (nginx-configuration
19843 (list (nginx-server-configuration
19844 (server-name '("www.example.com"))
19845 (root "/srv/http/www.example.com"))))))
19848 In addition to adding server blocks to the service configuration
19849 directly, this service can be extended by other services to add server
19850 blocks, as in this example:
19853 (simple-service 'my-extra-server nginx-service-type
19854 (list (nginx-server-configuration
19855 (root "/srv/http/extra-website")
19856 (try-files (list "$uri" "$uri/index.html")))))
19860 At startup, @command{nginx} has not yet read its configuration file, so
19861 it uses a default file to log error messages. If it fails to load its
19862 configuration file, that is where error messages are logged. After the
19863 configuration file is loaded, the default error log file changes as per
19864 configuration. In our case, startup error messages can be found in
19865 @file{/var/run/nginx/logs/error.log}, and after configuration in
19866 @file{/var/log/nginx/error.log}. The second location can be changed
19867 with the @var{log-directory} configuration option.
19869 @deffn {Data Type} nginx-configuration
19870 This data type represents the configuration for NGinx. Some
19871 configuration can be done through this and the other provided record
19872 types, or alternatively, a config file can be provided.
19875 @item @code{nginx} (default: @code{nginx})
19876 The nginx package to use.
19878 @item @code{log-directory} (default: @code{"/var/log/nginx"})
19879 The directory to which NGinx will write log files.
19881 @item @code{run-directory} (default: @code{"/var/run/nginx"})
19882 The directory in which NGinx will create a pid file, and write temporary
19885 @item @code{server-blocks} (default: @code{'()})
19886 A list of @dfn{server blocks} to create in the generated configuration
19887 file, the elements should be of type
19888 @code{<nginx-server-configuration>}.
19890 The following example would setup NGinx to serve @code{www.example.com}
19891 from the @code{/srv/http/www.example.com} directory, without using
19894 (service nginx-service-type
19895 (nginx-configuration
19897 (list (nginx-server-configuration
19898 (server-name '("www.example.com"))
19899 (root "/srv/http/www.example.com"))))))
19902 @item @code{upstream-blocks} (default: @code{'()})
19903 A list of @dfn{upstream blocks} to create in the generated configuration
19904 file, the elements should be of type
19905 @code{<nginx-upstream-configuration>}.
19907 Configuring upstreams through the @code{upstream-blocks} can be useful
19908 when combined with @code{locations} in the
19909 @code{<nginx-server-configuration>} records. The following example
19910 creates a server configuration with one location configuration, that
19911 will proxy requests to a upstream configuration, which will handle
19912 requests with two servers.
19917 (nginx-configuration
19919 (list (nginx-server-configuration
19920 (server-name '("www.example.com"))
19921 (root "/srv/http/www.example.com")
19924 (nginx-location-configuration
19926 (body '("proxy_pass http://server-proxy;"))))))))
19928 (list (nginx-upstream-configuration
19929 (name "server-proxy")
19930 (servers (list "server1.example.com"
19931 "server2.example.com")))))))
19934 @item @code{file} (default: @code{#f})
19935 If a configuration @var{file} is provided, this will be used, rather than
19936 generating a configuration file from the provided @code{log-directory},
19937 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
19938 proper operation, these arguments should match what is in @var{file} to ensure
19939 that the directories are created when the service is activated.
19941 This can be useful if you have an existing configuration file, or it's
19942 not possible to do what is required through the other parts of the
19943 nginx-configuration record.
19945 @item @code{server-names-hash-bucket-size} (default: @code{#f})
19946 Bucket size for the server names hash tables, defaults to @code{#f} to
19947 use the size of the processors cache line.
19949 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
19950 Maximum bucket size for the server names hash tables.
19952 @item @code{modules} (default: @code{'()})
19953 List of nginx dynamic modules to load. This should be a list of file
19954 names of loadable modules, as in this example:
19959 (file-append nginx-accept-language-module "\
19960 /etc/nginx/modules/ngx_http_accept_language_module.so")))
19963 @item @code{extra-content} (default: @code{""})
19964 Extra content for the @code{http} block. Should be string or a string
19965 valued G-expression.
19970 @deftp {Data Type} nginx-server-configuration
19971 Data type representing the configuration of an nginx server block.
19972 This type has the following parameters:
19975 @item @code{listen} (default: @code{'("80" "443 ssl")})
19976 Each @code{listen} directive sets the address and port for IP, or the
19977 path for a UNIX-domain socket on which the server will accept requests.
19978 Both address and port, or only address or only port can be specified.
19979 An address may also be a hostname, for example:
19982 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
19985 @item @code{server-name} (default: @code{(list 'default)})
19986 A list of server names this server represents. @code{'default} represents the
19987 default server for connections matching no other server.
19989 @item @code{root} (default: @code{"/srv/http"})
19990 Root of the website nginx will serve.
19992 @item @code{locations} (default: @code{'()})
19993 A list of @dfn{nginx-location-configuration} or
19994 @dfn{nginx-named-location-configuration} records to use within this
19997 @item @code{index} (default: @code{(list "index.html")})
19998 Index files to look for when clients ask for a directory. If it cannot be found,
19999 Nginx will send the list of files in the directory.
20001 @item @code{try-files} (default: @code{'()})
20002 A list of files whose existence is checked in the specified order.
20003 @code{nginx} will use the first file it finds to process the request.
20005 @item @code{ssl-certificate} (default: @code{#f})
20006 Where to find the certificate for secure connections. Set it to @code{#f} if
20007 you don't have a certificate or you don't want to use HTTPS.
20009 @item @code{ssl-certificate-key} (default: @code{#f})
20010 Where to find the private key for secure connections. Set it to @code{#f} if
20011 you don't have a key or you don't want to use HTTPS.
20013 @item @code{server-tokens?} (default: @code{#f})
20014 Whether the server should add its configuration to response.
20016 @item @code{raw-content} (default: @code{'()})
20017 A list of raw lines added to the server block.
20022 @deftp {Data Type} nginx-upstream-configuration
20023 Data type representing the configuration of an nginx @code{upstream}
20024 block. This type has the following parameters:
20028 Name for this group of servers.
20030 @item @code{servers}
20031 Specify the addresses of the servers in the group. The address can be
20032 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20033 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20034 prefix @samp{unix:}. For addresses using an IP address or domain name,
20035 the default port is 80, and a different port can be specified
20041 @deftp {Data Type} nginx-location-configuration
20042 Data type representing the configuration of an nginx @code{location}
20043 block. This type has the following parameters:
20047 URI which this location block matches.
20049 @anchor{nginx-location-configuration body}
20051 Body of the location block, specified as a list of strings. This can contain
20053 configuration directives. For example, to pass requests to a upstream
20054 server group defined using an @code{nginx-upstream-configuration} block,
20055 the following directive would be specified in the body @samp{(list "proxy_pass
20056 http://upstream-name;")}.
20061 @deftp {Data Type} nginx-named-location-configuration
20062 Data type representing the configuration of an nginx named location
20063 block. Named location blocks are used for request redirection, and not
20064 used for regular request processing. This type has the following
20069 Name to identify this location block.
20072 @xref{nginx-location-configuration body}, as the body for named location
20073 blocks can be used in a similar way to the
20074 @code{nginx-location-configuration body}. One restriction is that the
20075 body of a named location block cannot contain location blocks.
20080 @subsubheading Varnish Cache
20082 Varnish is a fast cache server that sits in between web applications
20083 and end users. It proxies requests from clients and caches the
20084 accessed URLs such that multiple requests for the same resource only
20085 creates one request to the back-end.
20087 @defvr {Scheme Variable} varnish-service-type
20088 Service type for the Varnish daemon.
20091 @deftp {Data Type} varnish-configuration
20092 Data type representing the @code{varnish} service configuration.
20093 This type has the following parameters:
20096 @item @code{package} (default: @code{varnish})
20097 The Varnish package to use.
20099 @item @code{name} (default: @code{"default"})
20100 A name for this Varnish instance. Varnish will create a directory in
20101 @file{/var/varnish/} with this name and keep temporary files there. If
20102 the name starts with a forward slash, it is interpreted as an absolute
20105 Pass the @code{-n} argument to other Varnish programs to connect to the
20106 named instance, e.g.@: @command{varnishncsa -n default}.
20108 @item @code{backend} (default: @code{"localhost:8080"})
20109 The backend to use. This option has no effect if @code{vcl} is set.
20111 @item @code{vcl} (default: #f)
20112 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20113 is @code{#f}, Varnish will proxy @code{backend} using the default
20114 configuration. Otherwise this must be a file-like object with valid
20117 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20118 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
20119 can do something along these lines:
20122 (define %gnu-mirror
20123 (plain-file "gnu.vcl"
20125 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20129 (services (cons (service varnish-service-type
20130 (varnish-configuration
20132 (vcl %gnu-mirror)))
20136 The configuration of an already running Varnish instance can be inspected
20137 and changed using the @command{varnishadm} program.
20139 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20140 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20141 comprehensive documentation on Varnish and its configuration language.
20143 @item @code{listen} (default: @code{'("localhost:80")})
20144 List of addresses Varnish will listen on.
20146 @item @code{storage} (default: @code{'("malloc,128m")})
20147 List of storage backends that will be available in VCL.
20149 @item @code{parameters} (default: @code{'()})
20150 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20152 @item @code{extra-options} (default: @code{'()})
20153 Additional arguments to pass to the @command{varnishd} process.
20158 @subsubheading Patchwork
20160 Patchwork is a patch tracking system. It can collect patches sent to a
20161 mailing list, and display them in a web interface.
20163 @defvr {Scheme Variable} patchwork-service-type
20164 Service type for Patchwork.
20167 The following example is an example of a minimal service for Patchwork, for
20168 the @code{patchwork.example.com} domain.
20171 (service patchwork-service-type
20172 (patchwork-configuration
20173 (domain "patchwork.example.com")
20175 (patchwork-settings-module
20176 (allowed-hosts (list domain))
20177 (default-from-email "patchwork@@patchwork.example.com")))
20178 (getmail-retriever-config
20179 (getmail-retriever-configuration
20180 (type "SimpleIMAPSSLRetriever")
20181 (server "imap.example.com")
20183 (username "patchwork")
20185 (list (file-append coreutils "/bin/cat")
20186 "/etc/getmail-patchwork-imap-password"))
20188 '((mailboxes . ("Patches"))))))))
20192 There are three records for configuring the Patchwork service. The
20193 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20194 within the HTTPD service.
20196 The @code{settings-module} field within the @code{<patchwork-configuration>}
20197 record can be populated with the @code{<patchwork-settings-module>} record,
20198 which describes a settings module that is generated within the Guix store.
20200 For the @code{database-configuration} field within the
20201 @code{<patchwork-settings-module>}, the
20202 @code{<patchwork-database-configuration>} must be used.
20204 @deftp {Data Type} patchwork-configuration
20205 Data type representing the Patchwork service configuration. This type has the
20206 following parameters:
20209 @item @code{patchwork} (default: @code{patchwork})
20210 The Patchwork package to use.
20212 @item @code{domain}
20213 The domain to use for Patchwork, this is used in the HTTPD service virtual
20216 @item @code{settings-module}
20217 The settings module to use for Patchwork. As a Django application, Patchwork
20218 is configured with a Python module containing the settings. This can either be
20219 an instance of the @code{<patchwork-settings-module>} record, any other record
20220 that represents the settings in the store, or a directory outside of the
20223 @item @code{static-path} (default: @code{"/static/"})
20224 The path under which the HTTPD service should serve the static files.
20226 @item @code{getmail-retriever-config}
20227 The getmail-retriever-configuration record value to use with
20228 Patchwork. Getmail will be configured with this value, the messages will be
20229 delivered to Patchwork.
20234 @deftp {Data Type} patchwork-settings-module
20235 Data type representing a settings module for Patchwork. Some of these
20236 settings relate directly to Patchwork, but others relate to Django, the web
20237 framework used by Patchwork, or the Django Rest Framework library. This type
20238 has the following parameters:
20241 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20242 The database connection settings used for Patchwork. See the
20243 @code{<patchwork-database-configuration>} record type for more information.
20245 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20246 Patchwork, as a Django web application uses a secret key for cryptographically
20247 signing values. This file should contain a unique unpredictable value.
20249 If this file does not exist, it will be created and populated with a random
20250 value by the patchwork-setup shepherd service.
20252 This setting relates to Django.
20254 @item @code{allowed-hosts}
20255 A list of valid hosts for this Patchwork service. This should at least include
20256 the domain specified in the @code{<patchwork-configuration>} record.
20258 This is a Django setting.
20260 @item @code{default-from-email}
20261 The email address from which Patchwork should send email by default.
20263 This is a Patchwork setting.
20265 @item @code{static-url} (default: @code{#f})
20266 The URL to use when serving static assets. It can be part of a URL, or a full
20267 URL, but must end in a @code{/}.
20269 If the default value is used, the @code{static-path} value from the
20270 @code{<patchwork-configuration>} record will be used.
20272 This is a Django setting.
20274 @item @code{admins} (default: @code{'()})
20275 Email addresses to send the details of errors that occur. Each value should
20276 be a list containing two elements, the name and then the email address.
20278 This is a Django setting.
20280 @item @code{debug?} (default: @code{#f})
20281 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20282 messages will be shown.
20284 This is a Django setting.
20286 @item @code{enable-rest-api?} (default: @code{#t})
20287 Whether to enable the Patchwork REST API.
20289 This is a Patchwork setting.
20291 @item @code{enable-xmlrpc?} (default: @code{#t})
20292 Whether to enable the XML RPC API.
20294 This is a Patchwork setting.
20296 @item @code{force-https-links?} (default: @code{#t})
20297 Whether to use HTTPS links on Patchwork pages.
20299 This is a Patchwork setting.
20301 @item @code{extra-settings} (default: @code{""})
20302 Extra code to place at the end of the Patchwork settings module.
20307 @deftp {Data Type} patchwork-database-configuration
20308 Data type representing the database configuration for Patchwork.
20311 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20312 The database engine to use.
20314 @item @code{name} (default: @code{"patchwork"})
20315 The name of the database to use.
20317 @item @code{user} (default: @code{"httpd"})
20318 The user to connect to the database as.
20320 @item @code{password} (default: @code{""})
20321 The password to use when connecting to the database.
20323 @item @code{host} (default: @code{""})
20324 The host to make the database connection to.
20326 @item @code{port} (default: @code{""})
20327 The port on which to connect to the database.
20332 @subsubheading FastCGI
20335 FastCGI is an interface between the front-end and the back-end of a web
20336 service. It is a somewhat legacy facility; new web services should
20337 generally just talk HTTP between the front-end and the back-end.
20338 However there are a number of back-end services such as PHP or the
20339 optimized HTTP Git repository access that use FastCGI, so we have
20340 support for it in Guix.
20342 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20343 dispatch some subset of its requests to the fastcgi backend, which
20344 listens on a local TCP or UNIX socket. There is an intermediary
20345 @code{fcgiwrap} program that sits between the actual backend process and
20346 the web server. The front-end indicates which backend program to run,
20347 passing that information to the @code{fcgiwrap} process.
20349 @defvr {Scheme Variable} fcgiwrap-service-type
20350 A service type for the @code{fcgiwrap} FastCGI proxy.
20353 @deftp {Data Type} fcgiwrap-configuration
20354 Data type representing the configuration of the @code{fcgiwrap} service.
20355 This type has the following parameters:
20357 @item @code{package} (default: @code{fcgiwrap})
20358 The fcgiwrap package to use.
20360 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20361 The socket on which the @code{fcgiwrap} process should listen, as a
20362 string. Valid @var{socket} values include
20363 @code{unix:@var{/path/to/unix/socket}},
20364 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20365 @code{tcp6:[@var{ipv6_addr}]:port}.
20367 @item @code{user} (default: @code{fcgiwrap})
20368 @itemx @code{group} (default: @code{fcgiwrap})
20369 The user and group names, as strings, under which to run the
20370 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20371 the user asks for the specific user or group names @code{fcgiwrap} that
20372 the corresponding user and/or group is present on the system.
20374 It is possible to configure a FastCGI-backed web service to pass HTTP
20375 authentication information from the front-end to the back-end, and to
20376 allow @code{fcgiwrap} to run the back-end process as a corresponding
20377 local user. To enable this capability on the back-end, run
20378 @code{fcgiwrap} as the @code{root} user and group. Note that this
20379 capability also has to be configured on the front-end as well.
20384 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20385 with some additional features useful for sites of any size.
20387 These features include:
20389 @item Adaptive process spawning
20390 @item Basic statistics (similar to Apache's mod_status)
20391 @item Advanced process management with graceful stop/start
20392 @item Ability to start workers with different uid/gid/chroot/environment
20393 and different php.ini (replaces safe_mode)
20394 @item Stdout & stderr logging
20395 @item Emergency restart in case of accidental opcode cache destruction
20396 @item Accelerated upload support
20397 @item Support for a "slowlog"
20398 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
20399 a special function to finish request & flush all data while continuing to do
20400 something time-consuming (video converting, stats processing, etc.)
20402 ...@: and much more.
20404 @defvr {Scheme Variable} php-fpm-service-type
20405 A Service type for @code{php-fpm}.
20408 @deftp {Data Type} php-fpm-configuration
20409 Data Type for php-fpm service configuration.
20411 @item @code{php} (default: @code{php})
20412 The php package to use.
20413 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
20414 The address on which to accept FastCGI requests. Valid syntaxes are:
20416 @item @code{"ip.add.re.ss:port"}
20417 Listen on a TCP socket to a specific address on a specific port.
20418 @item @code{"port"}
20419 Listen on a TCP socket to all addresses on a specific port.
20420 @item @code{"/path/to/unix/socket"}
20421 Listen on a unix socket.
20424 @item @code{user} (default: @code{php-fpm})
20425 User who will own the php worker processes.
20426 @item @code{group} (default: @code{php-fpm})
20427 Group of the worker processes.
20428 @item @code{socket-user} (default: @code{php-fpm})
20429 User who can speak to the php-fpm socket.
20430 @item @code{socket-group} (default: @code{nginx})
20431 Group that can speak to the php-fpm socket.
20432 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
20433 The process id of the php-fpm process is written to this file
20434 once the service has started.
20435 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
20436 Log for the php-fpm master process.
20437 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
20438 Detailed settings for the php-fpm process manager.
20441 @item @code{<php-fpm-dynamic-process-manager-configuration>}
20442 @item @code{<php-fpm-static-process-manager-configuration>}
20443 @item @code{<php-fpm-on-demand-process-manager-configuration>}
20445 @item @code{display-errors} (default @code{#f})
20446 Determines whether php errors and warning should be sent to clients
20447 and displayed in their browsers.
20448 This is useful for local php development, but a security risk for public sites,
20449 as error messages can reveal passwords and personal data.
20450 @item @code{timezone} (default @code{#f})
20451 Specifies @code{php_admin_value[date.timezone]} parameter.
20452 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
20453 This file will log the @code{stderr} outputs of php worker processes.
20454 Can be set to @code{#f} to disable logging.
20455 @item @code{file} (default @code{#f})
20456 An optional override of the whole configuration.
20457 You can use the @code{mixed-text-file} function or an absolute filepath for it.
20461 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
20462 Data Type for the @code{dynamic} php-fpm process manager. With the
20463 @code{dynamic} process manager, spare worker processes are kept around
20464 based on it's configured limits.
20466 @item @code{max-children} (default: @code{5})
20467 Maximum of worker processes.
20468 @item @code{start-servers} (default: @code{2})
20469 How many worker processes should be started on start-up.
20470 @item @code{min-spare-servers} (default: @code{1})
20471 How many spare worker processes should be kept around at minimum.
20472 @item @code{max-spare-servers} (default: @code{3})
20473 How many spare worker processes should be kept around at maximum.
20477 @deftp {Data type} php-fpm-static-process-manager-configuration
20478 Data Type for the @code{static} php-fpm process manager. With the
20479 @code{static} process manager, an unchanging number of worker processes
20482 @item @code{max-children} (default: @code{5})
20483 Maximum of worker processes.
20487 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
20488 Data Type for the @code{on-demand} php-fpm process manager. With the
20489 @code{on-demand} process manager, worker processes are only created as
20492 @item @code{max-children} (default: @code{5})
20493 Maximum of worker processes.
20494 @item @code{process-idle-timeout} (default: @code{10})
20495 The time in seconds after which a process with no requests is killed.
20500 @deffn {Scheme Procedure} nginx-php-fpm-location @
20501 [#:nginx-package nginx] @
20502 [socket (string-append "/var/run/php" @
20503 (version-major (package-version php)) @
20505 A helper function to quickly add php to an @code{nginx-server-configuration}.
20508 A simple services setup for nginx with php can look like this:
20510 (services (cons* (service dhcp-client-service-type)
20511 (service php-fpm-service-type)
20512 (service nginx-service-type
20513 (nginx-server-configuration
20514 (server-name '("example.com"))
20515 (root "/srv/http/")
20517 (list (nginx-php-location)))
20519 (ssl-certificate #f)
20520 (ssl-certificate-key #f)))
20524 @cindex cat-avatar-generator
20525 The cat avatar generator is a simple service to demonstrate the use of php-fpm
20526 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
20527 the hash of a user's email address.
20529 @deffn {Scheme Procedure} cat-avatar-generator-service @
20530 [#:cache-dir "/var/cache/cat-avatar-generator"] @
20531 [#:package cat-avatar-generator] @
20532 [#:configuration (nginx-server-configuration)]
20533 Returns an nginx-server-configuration that inherits @code{configuration}. It
20534 extends the nginx configuration to add a server block that serves @code{package},
20535 a version of cat-avatar-generator. During execution, cat-avatar-generator will
20536 be able to use @code{cache-dir} as its cache directory.
20539 A simple setup for cat-avatar-generator can look like this:
20541 (services (cons* (cat-avatar-generator-service
20543 (nginx-server-configuration
20544 (server-name '("example.com"))))
20549 @subsubheading Hpcguix-web
20551 @cindex hpcguix-web
20552 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
20553 program is a customizable web interface to browse Guix packages,
20554 initially designed for users of high-performance computing (HPC)
20557 @defvr {Scheme Variable} hpcguix-web-service-type
20558 The service type for @code{hpcguix-web}.
20561 @deftp {Data Type} hpcguix-web-configuration
20562 Data type for the hpcguix-web service configuration.
20566 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
20567 configuration. The main items available in this spec are:
20570 @item @code{title-prefix} (default: @code{"hpcguix | "})
20571 The page title prefix.
20573 @item @code{guix-command} (default: @code{"guix"})
20574 The @command{guix} command.
20576 @item @code{package-filter-proc} (default: @code{(const #t)})
20577 A procedure specifying how to filter packages that are displayed.
20579 @item @code{package-page-extension-proc} (default: @code{(const '())})
20580 Extension package for @code{hpcguix-web}.
20582 @item @code{menu} (default: @code{'()})
20583 Additional entry in page @code{menu}.
20585 @item @code{channels} (default: @code{%default-channels})
20586 List of channels from which the package list is built (@pxref{Channels}).
20588 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20589 The expiration time, in seconds, after which the package list is rebuilt from
20590 the latest instances of the given channels.
20593 See the hpcguix-web repository for a
20594 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20597 @item @code{package} (default: @code{hpcguix-web})
20598 The hpcguix-web package to use.
20602 A typical hpcguix-web service declaration looks like this:
20605 (service hpcguix-web-service-type
20606 (hpcguix-web-configuration
20608 #~(define site-config
20609 (hpcweb-configuration
20610 (title-prefix "Guix-HPC - ")
20611 (menu '(("/about" "ABOUT"))))))))
20615 The hpcguix-web service periodically updates the package list it publishes by
20616 pulling channels from Git. To that end, it needs to access X.509 certificates
20617 so that it can authenticate Git servers when communicating over HTTPS, and it
20618 assumes that @file{/etc/ssl/certs} contains those certificates.
20620 Thus, make sure to add @code{nss-certs} or another certificate package to the
20621 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20622 more information on X.509 certificates.
20625 @node Certificate Services
20626 @subsection Certificate Services
20629 @cindex HTTP, HTTPS
20630 @cindex Let's Encrypt
20631 @cindex TLS certificates
20632 The @code{(gnu services certbot)} module provides a service to
20633 automatically obtain a valid TLS certificate from the Let's Encrypt
20634 certificate authority. These certificates can then be used to serve
20635 content securely over HTTPS or other TLS-based protocols, with the
20636 knowledge that the client will be able to verify the server's
20639 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20640 @code{certbot} tool to automate the certification process. This tool
20641 first securely generates a key on the server. It then makes a request
20642 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20643 checks that the request originates from the host in question by using a
20644 challenge-response protocol, requiring the server to provide its
20645 response over HTTP. If that protocol completes successfully, the CA
20646 signs the key, resulting in a certificate. That certificate is valid
20647 for a limited period of time, and therefore to continue to provide TLS
20648 services, the server needs to periodically ask the CA to renew its
20651 The certbot service automates this process: the initial key
20652 generation, the initial certification request to the Let's Encrypt
20653 service, the web server challenge/response integration, writing the
20654 certificate to disk, the automated periodic renewals, and the deployment
20655 tasks associated with the renewal (e.g.@: reloading services, copying keys
20656 with different permissions).
20658 Certbot is run twice a day, at a random minute within the hour. It
20659 won't do anything until your certificates are due for renewal or
20660 revoked, but running it regularly would give your service a chance of
20661 staying online in case a Let's Encrypt-initiated revocation happened for
20664 By using this service, you agree to the ACME Subscriber Agreement, which
20665 can be found there:
20666 @url{https://acme-v01.api.letsencrypt.org/directory}.
20668 @defvr {Scheme Variable} certbot-service-type
20669 A service type for the @code{certbot} Let's Encrypt client. Its value
20670 must be a @code{certbot-configuration} record as in this example:
20673 (define %nginx-deploy-hook
20675 "nginx-deploy-hook"
20676 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20677 (kill pid SIGHUP))))
20679 (service certbot-service-type
20680 (certbot-configuration
20681 (email "foo@@example.net")
20684 (certificate-configuration
20685 (domains '("example.net" "www.example.net"))
20686 (deploy-hook %nginx-deploy-hook))
20687 (certificate-configuration
20688 (domains '("bar.example.net")))))))
20691 See below for details about @code{certbot-configuration}.
20694 @deftp {Data Type} certbot-configuration
20695 Data type representing the configuration of the @code{certbot} service.
20696 This type has the following parameters:
20699 @item @code{package} (default: @code{certbot})
20700 The certbot package to use.
20702 @item @code{webroot} (default: @code{/var/www})
20703 The directory from which to serve the Let's Encrypt challenge/response
20706 @item @code{certificates} (default: @code{()})
20707 A list of @code{certificates-configuration}s for which to generate
20708 certificates and request signatures. Each certificate has a @code{name}
20709 and several @code{domains}.
20712 Mandatory email used for registration, recovery contact, and important
20713 account notifications.
20715 @item @code{rsa-key-size} (default: @code{2048})
20716 Size of the RSA key.
20718 @item @code{default-location} (default: @i{see below})
20719 The default @code{nginx-location-configuration}. Because @code{certbot}
20720 needs to be able to serve challenges and responses, it needs to be able
20721 to run a web server. It does so by extending the @code{nginx} web
20722 service with an @code{nginx-server-configuration} listening on the
20723 @var{domains} on port 80, and which has a
20724 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20725 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20726 these nginx configuration data types.
20728 Requests to other URL paths will be matched by the
20729 @code{default-location}, which if present is added to all
20730 @code{nginx-server-configuration}s.
20732 By default, the @code{default-location} will issue a redirect from
20733 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20734 you to define what to serve on your site via @code{https}.
20736 Pass @code{#f} to not issue a default location.
20740 @deftp {Data Type} certificate-configuration
20741 Data type representing the configuration of a certificate.
20742 This type has the following parameters:
20745 @item @code{name} (default: @i{see below})
20746 This name is used by Certbot for housekeeping and in file paths; it
20747 doesn't affect the content of the certificate itself. To see
20748 certificate names, run @code{certbot certificates}.
20750 Its default is the first provided domain.
20752 @item @code{domains} (default: @code{()})
20753 The first domain provided will be the subject CN of the certificate, and
20754 all domains will be Subject Alternative Names on the certificate.
20756 @item @code{challenge} (default: @code{#f})
20757 The challenge type that has to be run by certbot. If @code{#f} is specified,
20758 default to the HTTP challenge. If a value is specified, defaults to the
20759 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20760 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
20761 and gives Let's Encrypt permission to log the public IP address of the
20762 requesting machine.
20764 @item @code{authentication-hook} (default: @code{#f})
20765 Command to be run in a shell once for each certificate challenge to be
20766 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20767 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20768 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20769 file name of the resource requested when performing an HTTP-01 challenge.
20771 @item @code{cleanup-hook} (default: @code{#f})
20772 Command to be run in a shell once for each certificate challenge that
20773 have been answered by the @code{auth-hook}. For this command, the shell
20774 variables available in the @code{auth-hook} script are still available, and
20775 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20776 of the @code{auth-hook} script.
20778 @item @code{deploy-hook} (default: @code{#f})
20779 Command to be run in a shell once for each successfully issued
20780 certificate. For this command, the shell variable
20781 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20782 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20783 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20784 contain a space-delimited list of renewed certificate domains (for
20785 example, @samp{"example.com www.example.com"}.
20790 For each @code{certificate-configuration}, the certificate is saved to
20791 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20792 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20794 @subsection DNS Services
20795 @cindex DNS (domain name system)
20796 @cindex domain name system (DNS)
20798 The @code{(gnu services dns)} module provides services related to the
20799 @dfn{domain name system} (DNS). It provides a server service for hosting
20800 an @emph{authoritative} DNS server for multiple zones, slave or master.
20801 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20802 caching and forwarding DNS server for the LAN, which uses
20803 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20805 @subsubheading Knot Service
20807 An example configuration of an authoritative server for two zones, one master
20811 (define-zone-entries example.org.zone
20812 ;; Name TTL Class Type Data
20813 ("@@" "" "IN" "A" "127.0.0.1")
20814 ("@@" "" "IN" "NS" "ns")
20815 ("ns" "" "IN" "A" "127.0.0.1"))
20817 (define master-zone
20818 (knot-zone-configuration
20819 (domain "example.org")
20821 (origin "example.org")
20822 (entries example.org.zone)))))
20825 (knot-zone-configuration
20826 (domain "plop.org")
20827 (dnssec-policy "default")
20828 (master (list "plop-master"))))
20830 (define plop-master
20831 (knot-remote-configuration
20833 (address (list "208.76.58.171"))))
20837 (services (cons* (service knot-service-type
20838 (knot-configuration
20839 (remotes (list plop-master))
20840 (zones (list master-zone slave-zone))))
20845 @deffn {Scheme Variable} knot-service-type
20846 This is the type for the Knot DNS server.
20848 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20849 zones, that is to say domain names you would buy from a registrar. This server
20850 is not a resolver, meaning that it can only resolve names for which it is
20851 authoritative. This server can be configured to serve zones as a master server
20852 or a slave server as a per-zone basis. Slave zones will get their data from
20853 masters, and will serve it as an authoritative server. From the point of view
20854 of a resolver, there is no difference between master and slave.
20856 The following data types are used to configure the Knot DNS server:
20859 @deftp {Data Type} knot-key-configuration
20860 Data type representing a key.
20861 This type has the following parameters:
20864 @item @code{id} (default: @code{""})
20865 An identifier for other configuration fields to refer to this key. IDs must
20866 be unique and must not be empty.
20868 @item @code{algorithm} (default: @code{#f})
20869 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
20870 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
20871 and @code{'hmac-sha512}.
20873 @item @code{secret} (default: @code{""})
20874 The secret key itself.
20879 @deftp {Data Type} knot-acl-configuration
20880 Data type representing an Access Control List (ACL) configuration.
20881 This type has the following parameters:
20884 @item @code{id} (default: @code{""})
20885 An identifier for ether configuration fields to refer to this key. IDs must be
20886 unique and must not be empty.
20888 @item @code{address} (default: @code{'()})
20889 An ordered list of IP addresses, network subnets, or network ranges represented
20890 with strings. The query must match one of them. Empty value means that
20891 address match is not required.
20893 @item @code{key} (default: @code{'()})
20894 An ordered list of references to keys represented with strings. The string
20895 must match a key ID defined in a @code{knot-key-configuration}. No key means
20896 that a key is not require to match that ACL.
20898 @item @code{action} (default: @code{'()})
20899 An ordered list of actions that are permitted or forbidden by this ACL. Possible
20900 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
20901 and @code{'update}.
20903 @item @code{deny?} (default: @code{#f})
20904 When true, the ACL defines restrictions. Listed actions are forbidden. When
20905 false, listed actions are allowed.
20910 @deftp {Data Type} zone-entry
20911 Data type represnting a record entry in a zone file.
20912 This type has the following parameters:
20915 @item @code{name} (default: @code{"@@"})
20916 The name of the record. @code{"@@"} refers to the origin of the zone. Names
20917 are relative to the origin of the zone. For example, in the @code{example.org}
20918 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
20919 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
20920 refers to @code{ns.example.org}.
20922 @item @code{ttl} (default: @code{""})
20923 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
20925 @item @code{class} (default: @code{"IN"})
20926 The class of the record. Knot currently supports only @code{"IN"} and
20927 partially @code{"CH"}.
20929 @item @code{type} (default: @code{"A"})
20930 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
20931 address), NS (Name Server) and MX (Mail eXchange). Many other types are
20934 @item @code{data} (default: @code{""})
20935 The data contained in the record. For instance an IP address associated with
20936 an A record, or a domain name associated with an NS record. Remember that
20937 domain names are relative to the origin unless they end with a dot.
20942 @deftp {Data Type} zone-file
20943 Data type representing the content of a zone file.
20944 This type has the following parameters:
20947 @item @code{entries} (default: @code{'()})
20948 The list of entries. The SOA record is taken care of, so you don't need to
20949 put it in the list of entries. This list should probably contain an entry
20950 for your primary authoritative DNS server. Other than using a list of entries
20951 directly, you can use @code{define-zone-entries} to define a object containing
20952 the list of entries more easily, that you can later pass to the @code{entries}
20953 field of the @code{zone-file}.
20955 @item @code{origin} (default: @code{""})
20956 The name of your zone. This parameter cannot be empty.
20958 @item @code{ns} (default: @code{"ns"})
20959 The domain of your primary authoritative DNS server. The name is relative to
20960 the origin, unless it ends with a dot. It is mandatory that this primary
20961 DNS server corresponds to an NS record in the zone and that it is associated
20962 to an IP address in the list of entries.
20964 @item @code{mail} (default: @code{"hostmaster"})
20965 An email address people can contact you at, as the owner of the zone. This
20966 is translated as @code{<mail>@@<origin>}.
20968 @item @code{serial} (default: @code{1})
20969 The serial number of the zone. As this is used to keep track of changes by
20970 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
20971 Always increment it when you make a change in your zone.
20973 @item @code{refresh} (default: @code{(* 2 24 3600)})
20974 The frequency at which slaves will do a zone transfer. This value is a number
20975 of seconds. It can be computed by multiplications or with
20976 @code{(string->duration)}.
20978 @item @code{retry} (default: @code{(* 15 60)})
20979 The period after which a slave will retry to contact its master when it fails
20980 to do so a first time.
20982 @item @code{expiry} (default: @code{(* 14 24 3600)})
20983 Default TTL of records. Existing records are considered correct for at most
20984 this amount of time. After this period, resolvers will invalidate their cache
20985 and check again that it still exists.
20987 @item @code{nx} (default: @code{3600})
20988 Default TTL of inexistant records. This delay is usually short because you want
20989 your new domains to reach everyone quickly.
20994 @deftp {Data Type} knot-remote-configuration
20995 Data type representing a remote configuration.
20996 This type has the following parameters:
20999 @item @code{id} (default: @code{""})
21000 An identifier for other configuration fields to refer to this remote. IDs must
21001 be unique and must not be empty.
21003 @item @code{address} (default: @code{'()})
21004 An ordered list of destination IP addresses. Addresses are tried in sequence.
21005 An optional port can be given with the @@ separator. For instance:
21006 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21008 @item @code{via} (default: @code{'()})
21009 An ordered list of source IP addresses. An empty list will have Knot choose
21010 an appropriate source IP. An optional port can be given with the @@ separator.
21011 The default is to choose at random.
21013 @item @code{key} (default: @code{#f})
21014 A reference to a key, that is a string containing the identifier of a key
21015 defined in a @code{knot-key-configuration} field.
21020 @deftp {Data Type} knot-keystore-configuration
21021 Data type representing a keystore to hold dnssec keys.
21022 This type has the following parameters:
21025 @item @code{id} (default: @code{""})
21026 The id of the keystore. It must not be empty.
21028 @item @code{backend} (default: @code{'pem})
21029 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21031 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21032 The configuration string of the backend. An example for the PKCS#11 is:
21033 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21034 For the pem backend, the string reprensents a path in the file system.
21039 @deftp {Data Type} knot-policy-configuration
21040 Data type representing a dnssec policy. Knot DNS is able to automatically
21041 sign your zones. It can either generate and manage your keys automatically or
21042 use keys that you generate.
21044 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21045 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21046 zone. In order to be trusted, the KSK needs to be present in the parent zone
21047 (usually a top-level domain). If your registrar supports dnssec, you will
21048 have to send them your KSK's hash so they can add a DS record in their zone.
21049 This is not automated and need to be done each time you change your KSK.
21051 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21052 easily and use weaker cryptographic functions (they use lower parameters) in
21053 order to sign records quickly, so they are changed often. The KSK however
21054 requires manual interaction with the registrar, so they are changed less often
21055 and use stronger parameters because they sign only one record.
21057 This type has the following parameters:
21060 @item @code{id} (default: @code{""})
21061 The id of the policy. It must not be empty.
21063 @item @code{keystore} (default: @code{"default"})
21064 A reference to a keystore, that is a string containing the identifier of a
21065 keystore defined in a @code{knot-keystore-configuration} field. The
21066 @code{"default"} identifier means the default keystore (a kasp database that
21067 was setup by this service).
21069 @item @code{manual?} (default: @code{#f})
21070 Whether the key management is manual or automatic.
21072 @item @code{single-type-signing?} (default: @code{#f})
21073 When @code{#t}, use the Single-Type Signing Scheme.
21075 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21076 An algorithm of signing keys and issued signatures.
21078 @item @code{ksk-size} (default: @code{256})
21079 The length of the KSK. Note that this value is correct for the default
21080 algorithm, but would be unsecure for other algorithms.
21082 @item @code{zsk-size} (default: @code{256})
21083 The length of the ZSK. Note that this value is correct for the default
21084 algorithm, but would be unsecure for other algorithms.
21086 @item @code{dnskey-ttl} (default: @code{'default})
21087 The TTL value for DNSKEY records added into zone apex. The special
21088 @code{'default} value means same as the zone SOA TTL.
21090 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21091 The period between ZSK publication and the next rollover initiation.
21093 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21094 An extra delay added for each key rollover step. This value should be high
21095 enough to cover propagation of data from the master server to all slaves.
21097 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21098 A validity period of newly issued signatures.
21100 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21101 A period how long before a signature expiration the signature will be refreshed.
21103 @item @code{nsec3?} (default: @code{#f})
21104 When @code{#t}, NSEC3 will be used instead of NSEC.
21106 @item @code{nsec3-iterations} (default: @code{5})
21107 The number of additional times the hashing is performed.
21109 @item @code{nsec3-salt-length} (default: @code{8})
21110 The length of a salt field in octets, which is appended to the original owner
21111 name before hashing.
21113 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21114 The validity period of newly issued salt field.
21119 @deftp {Data Type} knot-zone-configuration
21120 Data type representing a zone served by Knot.
21121 This type has the following parameters:
21124 @item @code{domain} (default: @code{""})
21125 The domain served by this configuration. It must not be empty.
21127 @item @code{file} (default: @code{""})
21128 The file where this zone is saved. This parameter is ignored by master zones.
21129 Empty means default location that depends on the domain name.
21131 @item @code{zone} (default: @code{(zone-file)})
21132 The content of the zone file. This parameter is ignored by slave zones. It
21133 must contain a zone-file record.
21135 @item @code{master} (default: @code{'()})
21136 A list of master remotes. When empty, this zone is a master. When set, this
21137 zone is a slave. This is a list of remotes identifiers.
21139 @item @code{ddns-master} (default: @code{#f})
21140 The main master. When empty, it defaults to the first master in the list of
21143 @item @code{notify} (default: @code{'()})
21144 A list of slave remote identifiers.
21146 @item @code{acl} (default: @code{'()})
21147 A list of acl identifiers.
21149 @item @code{semantic-checks?} (default: @code{#f})
21150 When set, this adds more semantic checks to the zone.
21152 @item @code{disable-any?} (default: @code{#f})
21153 When set, this forbids queries of the ANY type.
21155 @item @code{zonefile-sync} (default: @code{0})
21156 The delay between a modification in memory and on disk. 0 means immediate
21159 @item @code{zonefile-load} (default: @code{#f})
21160 The way the zone file contents are applied during zone load. Possible values
21164 @item @code{#f} for using the default value from Knot,
21165 @item @code{'none} for not using the zone file at all,
21166 @item @code{'difference} for computing the difference between already available
21167 contents and zone contents and applying it to the current zone contents,
21168 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21169 ignoring the SOA serial in the zone file, while the server takes care of it
21171 @item @code{'whole} for loading zone contents from the zone file.
21174 @item @code{journal-content} (default: @code{#f})
21175 The way the journal is used to store zone and its changes. Possible values
21176 are @code{'none} to not use it at all, @code{'changes} to store changes and
21177 @code{'all} to store contents. @code{#f} does not set this option, so the
21178 default value from Knot is used.
21180 @item @code{max-journal-usage} (default: @code{#f})
21181 The maximum size for the journal on disk. @code{#f} does not set this option,
21182 so the default value from Knot is used.
21184 @item @code{max-journal-depth} (default: @code{#f})
21185 The maximum size of the history. @code{#f} does not set this option, so the
21186 default value from Knot is used.
21188 @item @code{max-zone-size} (default: @code{#f})
21189 The maximum size of the zone file. This limit is enforced for incoming
21190 transfer and updates. @code{#f} does not set this option, so the default
21191 value from Knot is used.
21193 @item @code{dnssec-policy} (default: @code{#f})
21194 A reference to a @code{knot-policy-configuration} record, or the special
21195 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21198 @item @code{serial-policy} (default: @code{'increment})
21199 A policy between @code{'increment} and @code{'unixtime}.
21204 @deftp {Data Type} knot-configuration
21205 Data type representing the Knot configuration.
21206 This type has the following parameters:
21209 @item @code{knot} (default: @code{knot})
21212 @item @code{run-directory} (default: @code{"/var/run/knot"})
21213 The run directory. This directory will be used for pid file and sockets.
21215 @item @code{includes} (default: @code{'()})
21216 A list of strings or file-like objects denoting other files that must be
21217 included at the top of the configuration file.
21219 @cindex secrets, Knot service
21220 This can be used to manage secrets out-of-band. For example, secret
21221 keys may be stored in an out-of-band file not managed by Guix, and
21222 thus not visible in @file{/gnu/store}---e.g., you could store secret
21223 key configuration in @file{/etc/knot/secrets.conf} and add this file
21224 to the @code{includes} list.
21226 One can generate a secret tsig key (for nsupdate and zone transfers with the
21227 keymgr command from the knot package. Note that the package is not automatically
21228 installed by the service. The following example shows how to generate a new
21232 keymgr -t mysecret > /etc/knot/secrets.conf
21233 chmod 600 /etc/knot/secrets.conf
21236 Also note that the generated key will be named @var{mysecret}, so it is the
21237 name that needs to be used in the @var{key} field of the
21238 @code{knot-acl-configuration} record and in other places that need to refer
21241 It can also be used to add configuration not supported by this interface.
21243 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21244 An ip address on which to listen.
21246 @item @code{listen-v6} (default: @code{"::"})
21247 An ip address on which to listen.
21249 @item @code{listen-port} (default: @code{53})
21250 A port on which to listen.
21252 @item @code{keys} (default: @code{'()})
21253 The list of knot-key-configuration used by this configuration.
21255 @item @code{acls} (default: @code{'()})
21256 The list of knot-acl-configuration used by this configuration.
21258 @item @code{remotes} (default: @code{'()})
21259 The list of knot-remote-configuration used by this configuration.
21261 @item @code{zones} (default: @code{'()})
21262 The list of knot-zone-configuration used by this configuration.
21267 @subsubheading Knot Resolver Service
21269 @deffn {Scheme Variable} knot-resolver-service-type
21270 This this the type of the knot resolver service, whose value should be
21271 an @code{knot-resolver-configuration} object as in this example:
21274 (service knot-resolver-service-type
21275 (knot-resolver-configuration
21276 (kresd-config-file (plain-file "kresd.conf" "
21277 net.listen('192.168.0.1', 5353)
21278 user('knot-resolver', 'knot-resolver')
21279 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21280 cache.size = 100 * MB
21284 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21287 @deftp {Data Type} knot-resolver-configuration
21288 Data type representing the configuration of knot-resolver.
21291 @item @code{package} (default: @var{knot-resolver})
21292 Package object of the knot DNS resolver.
21294 @item @code{kresd-config-file} (default: %kresd.conf)
21295 File-like object of the kresd configuration file to use, by default it
21296 will listen on @code{127.0.0.1} and @code{::1}.
21298 @item @code{garbage-collection-interval} (default: 1000)
21299 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21305 @subsubheading Dnsmasq Service
21307 @deffn {Scheme Variable} dnsmasq-service-type
21308 This is the type of the dnsmasq service, whose value should be an
21309 @code{dnsmasq-configuration} object as in this example:
21312 (service dnsmasq-service-type
21313 (dnsmasq-configuration
21315 (servers '("192.168.1.1"))))
21319 @deftp {Data Type} dnsmasq-configuration
21320 Data type representing the configuration of dnsmasq.
21323 @item @code{package} (default: @var{dnsmasq})
21324 Package object of the dnsmasq server.
21326 @item @code{no-hosts?} (default: @code{#f})
21327 When true, don't read the hostnames in /etc/hosts.
21329 @item @code{port} (default: @code{53})
21330 The port to listen on. Setting this to zero completely disables DNS
21331 responses, leaving only DHCP and/or TFTP functions.
21333 @item @code{local-service?} (default: @code{#t})
21334 Accept DNS queries only from hosts whose address is on a local subnet,
21335 ie a subnet for which an interface exists on the server.
21337 @item @code{listen-addresses} (default: @code{'()})
21338 Listen on the given IP addresses.
21340 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21341 The file to read the IP address of the upstream nameservers from.
21343 @item @code{no-resolv?} (default: @code{#f})
21344 When true, don't read @var{resolv-file}.
21346 @item @code{servers} (default: @code{'()})
21347 Specify IP address of upstream servers directly.
21349 @item @code{cache-size} (default: @code{150})
21350 Set the size of dnsmasq's cache. Setting the cache size to zero
21353 @item @code{negative-cache?} (default: @code{#t})
21354 When false, disable negative caching.
21359 @subsubheading ddclient Service
21362 The ddclient service described below runs the ddclient daemon, which takes
21363 care of automatically updating DNS entries for service providers such as
21364 @uref{https://dyn.com/dns/, Dyn}.
21366 The following example show instantiates the service with its default
21370 (service ddclient-service-type)
21373 Note that ddclient needs to access credentials that are stored in a
21374 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
21375 @code{secret-file} below.) You are expected to create this file manually, in
21376 an ``out-of-band'' fashion (you @emph{could} make this file part of the
21377 service configuration, for instance by using @code{plain-file}, but it will be
21378 world-readable @i{via} @file{/gnu/store}.) See the examples in the
21379 @file{share/ddclient} directory of the @code{ddclient} package.
21381 @c %start of fragment
21383 Available @code{ddclient-configuration} fields are:
21385 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
21386 The ddclient package.
21390 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
21391 The period after which ddclient will retry to check IP and domain name.
21393 Defaults to @samp{300}.
21397 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
21398 Use syslog for the output.
21400 Defaults to @samp{#t}.
21404 @deftypevr {@code{ddclient-configuration} parameter} string mail
21407 Defaults to @samp{"root"}.
21411 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
21412 Mail failed update to user.
21414 Defaults to @samp{"root"}.
21418 @deftypevr {@code{ddclient-configuration} parameter} string pid
21419 The ddclient PID file.
21421 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
21425 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
21426 Enable SSL support.
21428 Defaults to @samp{#t}.
21432 @deftypevr {@code{ddclient-configuration} parameter} string user
21433 Specifies the user name or ID that is used when running ddclient
21436 Defaults to @samp{"ddclient"}.
21440 @deftypevr {@code{ddclient-configuration} parameter} string group
21441 Group of the user who will run the ddclient program.
21443 Defaults to @samp{"ddclient"}.
21447 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
21448 Secret file which will be appended to @file{ddclient.conf} file. This
21449 file contains credentials for use by ddclient. You are expected to
21450 create it manually.
21452 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
21456 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
21457 Extra options will be appended to @file{ddclient.conf} file.
21459 Defaults to @samp{()}.
21464 @c %end of fragment
21468 @subsection VPN Services
21469 @cindex VPN (virtual private network)
21470 @cindex virtual private network (VPN)
21472 The @code{(gnu services vpn)} module provides services related to
21473 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
21474 your machine to connect to a VPN, and a @emph{server} service for your machine
21475 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
21477 @deffn {Scheme Procedure} openvpn-client-service @
21478 [#:config (openvpn-client-configuration)]
21480 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
21483 @deffn {Scheme Procedure} openvpn-server-service @
21484 [#:config (openvpn-server-configuration)]
21486 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
21488 Both can be run simultaneously.
21491 @c %automatically generated documentation
21493 Available @code{openvpn-client-configuration} fields are:
21495 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
21496 The OpenVPN package.
21500 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
21501 The OpenVPN pid file.
21503 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21507 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
21508 The protocol (UDP or TCP) used to open a channel between clients and
21511 Defaults to @samp{udp}.
21515 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
21516 The device type used to represent the VPN connection.
21518 Defaults to @samp{tun}.
21522 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
21523 The certificate authority to check connections against.
21525 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21529 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
21530 The certificate of the machine the daemon is running on. It should be
21531 signed by the authority given in @code{ca}.
21533 Defaults to @samp{"/etc/openvpn/client.crt"}.
21537 @deftypevr {@code{openvpn-client-configuration} parameter} string key
21538 The key of the machine the daemon is running on. It must be the key whose
21539 certificate is @code{cert}.
21541 Defaults to @samp{"/etc/openvpn/client.key"}.
21545 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
21546 Whether to use the lzo compression algorithm.
21548 Defaults to @samp{#t}.
21552 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
21553 Don't re-read key files across SIGUSR1 or --ping-restart.
21555 Defaults to @samp{#t}.
21559 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
21560 Don't close and reopen TUN/TAP device or run up/down scripts across
21561 SIGUSR1 or --ping-restart restarts.
21563 Defaults to @samp{#t}.
21567 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
21570 Defaults to @samp{3}.
21574 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
21575 Add an additional layer of HMAC authentication on top of the TLS control
21576 channel to protect against DoS attacks.
21578 Defaults to @samp{#f}.
21582 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
21583 Whether to check the server certificate has server usage extension.
21585 Defaults to @samp{#t}.
21589 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
21590 Bind to a specific local port number.
21592 Defaults to @samp{#f}.
21596 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
21597 Retry resolving server address.
21599 Defaults to @samp{#t}.
21603 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
21604 A list of remote servers to connect to.
21606 Defaults to @samp{()}.
21608 Available @code{openvpn-remote-configuration} fields are:
21610 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
21613 Defaults to @samp{"my-server"}.
21617 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21618 Port number the server listens to.
21620 Defaults to @samp{1194}.
21625 @c %end of automatic openvpn-client documentation
21627 @c %automatically generated documentation
21629 Available @code{openvpn-server-configuration} fields are:
21631 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21632 The OpenVPN package.
21636 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21637 The OpenVPN pid file.
21639 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21643 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21644 The protocol (UDP or TCP) used to open a channel between clients and
21647 Defaults to @samp{udp}.
21651 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
21652 The device type used to represent the VPN connection.
21654 Defaults to @samp{tun}.
21658 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
21659 The certificate authority to check connections against.
21661 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21665 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
21666 The certificate of the machine the daemon is running on. It should be
21667 signed by the authority given in @code{ca}.
21669 Defaults to @samp{"/etc/openvpn/client.crt"}.
21673 @deftypevr {@code{openvpn-server-configuration} parameter} string key
21674 The key of the machine the daemon is running on. It must be the key whose
21675 certificate is @code{cert}.
21677 Defaults to @samp{"/etc/openvpn/client.key"}.
21681 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
21682 Whether to use the lzo compression algorithm.
21684 Defaults to @samp{#t}.
21688 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21689 Don't re-read key files across SIGUSR1 or --ping-restart.
21691 Defaults to @samp{#t}.
21695 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21696 Don't close and reopen TUN/TAP device or run up/down scripts across
21697 SIGUSR1 or --ping-restart restarts.
21699 Defaults to @samp{#t}.
21703 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21706 Defaults to @samp{3}.
21710 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21711 Add an additional layer of HMAC authentication on top of the TLS control
21712 channel to protect against DoS attacks.
21714 Defaults to @samp{#f}.
21718 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21719 Specifies the port number on which the server listens.
21721 Defaults to @samp{1194}.
21725 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21726 An ip and mask specifying the subnet inside the virtual network.
21728 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21732 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21733 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21735 Defaults to @samp{#f}.
21739 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21740 The Diffie-Hellman parameters file.
21742 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21746 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21747 The file that records client IPs.
21749 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21753 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21754 When true, the server will act as a gateway for its clients.
21756 Defaults to @samp{#f}.
21760 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21761 When true, clients are allowed to talk to each other inside the VPN.
21763 Defaults to @samp{#f}.
21767 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21768 Causes ping-like messages to be sent back and forth over the link so
21769 that each side knows when the other side has gone down. @code{keepalive}
21770 requires a pair. The first element is the period of the ping sending,
21771 and the second element is the timeout before considering the other side
21776 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21777 The maximum number of clients.
21779 Defaults to @samp{100}.
21783 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21784 The status file. This file shows a small report on current connection.
21785 It is truncated and rewritten every minute.
21787 Defaults to @samp{"/var/run/openvpn/status"}.
21791 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21792 The list of configuration for some clients.
21794 Defaults to @samp{()}.
21796 Available @code{openvpn-ccd-configuration} fields are:
21798 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21801 Defaults to @samp{"client"}.
21805 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21808 Defaults to @samp{#f}.
21812 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21815 Defaults to @samp{#f}.
21822 @c %end of automatic openvpn-server documentation
21825 @node Network File System
21826 @subsection Network File System
21829 The @code{(gnu services nfs)} module provides the following services,
21830 which are most commonly used in relation to mounting or exporting
21831 directory trees as @dfn{network file systems} (NFS).
21833 @subsubheading RPC Bind Service
21836 The RPC Bind service provides a facility to map program numbers into
21837 universal addresses.
21838 Many NFS related services use this facility. Hence it is automatically
21839 started when a dependent service starts.
21841 @defvr {Scheme Variable} rpcbind-service-type
21842 A service type for the RPC portmapper daemon.
21846 @deftp {Data Type} rpcbind-configuration
21847 Data type representing the configuration of the RPC Bind Service.
21848 This type has the following parameters:
21850 @item @code{rpcbind} (default: @code{rpcbind})
21851 The rpcbind package to use.
21853 @item @code{warm-start?} (default: @code{#t})
21854 If this parameter is @code{#t}, then the daemon will read a
21855 state file on startup thus reloading state information saved by a previous
21861 @subsubheading Pipefs Pseudo File System
21865 The pipefs file system is used to transfer NFS related data
21866 between the kernel and user space programs.
21868 @defvr {Scheme Variable} pipefs-service-type
21869 A service type for the pipefs pseudo file system.
21872 @deftp {Data Type} pipefs-configuration
21873 Data type representing the configuration of the pipefs pseudo file system service.
21874 This type has the following parameters:
21876 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21877 The directory to which the file system is to be attached.
21882 @subsubheading GSS Daemon Service
21885 @cindex global security system
21887 The @dfn{global security system} (GSS) daemon provides strong security for RPC
21889 Before exchanging RPC requests an RPC client must establish a security
21890 context. Typically this is done using the Kerberos command @command{kinit}
21891 or automatically at login time using PAM services (@pxref{Kerberos Services}).
21893 @defvr {Scheme Variable} gss-service-type
21894 A service type for the Global Security System (GSS) daemon.
21897 @deftp {Data Type} gss-configuration
21898 Data type representing the configuration of the GSS daemon service.
21899 This type has the following parameters:
21901 @item @code{nfs-utils} (default: @code{nfs-utils})
21902 The package in which the @command{rpc.gssd} command is to be found.
21904 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21905 The directory where the pipefs file system is mounted.
21911 @subsubheading IDMAP Daemon Service
21913 @cindex name mapper
21915 The idmap daemon service provides mapping between user IDs and user names.
21916 Typically it is required in order to access file systems mounted via NFSv4.
21918 @defvr {Scheme Variable} idmap-service-type
21919 A service type for the Identity Mapper (IDMAP) daemon.
21922 @deftp {Data Type} idmap-configuration
21923 Data type representing the configuration of the IDMAP daemon service.
21924 This type has the following parameters:
21926 @item @code{nfs-utils} (default: @code{nfs-utils})
21927 The package in which the @command{rpc.idmapd} command is to be found.
21929 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21930 The directory where the pipefs file system is mounted.
21932 @item @code{domain} (default: @code{#f})
21933 The local NFSv4 domain name.
21934 This must be a string or @code{#f}.
21935 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
21940 @node Continuous Integration
21941 @subsection Continuous Integration
21943 @cindex continuous integration
21944 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
21945 continuous integration tool for Guix. It can be used both for development and
21946 for providing substitutes to others (@pxref{Substitutes}).
21948 The @code{(gnu services cuirass)} module provides the following service.
21950 @defvr {Scheme Procedure} cuirass-service-type
21951 The type of the Cuirass service. Its value must be a
21952 @code{cuirass-configuration} object, as described below.
21955 To add build jobs, you have to set the @code{specifications} field of the
21956 configuration. Here is an example of a service that polls the Guix repository
21957 and builds the packages from a manifest. Some of the packages are defined in
21958 the @code{"custom-packages"} input, which is the equivalent of
21959 @code{GUIX_PACKAGE_PATH}.
21962 (define %cuirass-specs
21964 '((#:name . "my-manifest")
21965 (#:load-path-inputs . ("guix"))
21966 (#:package-path-inputs . ("custom-packages"))
21967 (#:proc-input . "guix")
21968 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
21969 (#:proc . cuirass-jobs)
21970 (#:proc-args . ((subset . "manifests")
21971 (systems . ("x86_64-linux"))
21972 (manifests . (("config" . "guix/manifest.scm")))))
21973 (#:inputs . (((#:name . "guix")
21974 (#:url . "git://git.savannah.gnu.org/guix.git")
21975 (#:load-path . ".")
21976 (#:branch . "master")
21977 (#:no-compile? . #t))
21978 ((#:name . "config")
21979 (#:url . "https://git.example.org/config.git")
21980 (#:load-path . ".")
21981 (#:branch . "master")
21982 (#:no-compile? . #t))
21983 ((#:name . "custom-packages")
21984 (#:url . "https://git.example.org/custom-packages.git")
21985 (#:load-path . ".")
21986 (#:branch . "master")
21987 (#:no-compile? . #t)))))))
21989 (service cuirass-service-type
21990 (cuirass-configuration
21991 (specifications %cuirass-specs)))
21994 While information related to build jobs is located directly in the
21995 specifications, global settings for the @command{cuirass} process are
21996 accessible in other @code{cuirass-configuration} fields.
21998 @deftp {Data Type} cuirass-configuration
21999 Data type representing the configuration of Cuirass.
22002 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22003 Location of the log file.
22005 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22006 Location of the log file used by the web interface.
22008 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22009 Location of the repository cache.
22011 @item @code{user} (default: @code{"cuirass"})
22012 Owner of the @code{cuirass} process.
22014 @item @code{group} (default: @code{"cuirass"})
22015 Owner's group of the @code{cuirass} process.
22017 @item @code{interval} (default: @code{60})
22018 Number of seconds between the poll of the repositories followed by the
22021 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22022 Location of sqlite database which contains the build results and previously
22023 added specifications.
22025 @item @code{ttl} (default: @code{(* 30 24 3600)})
22026 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22027 are registered for build results. This means that build results are protected
22028 from garbage collection for at least @var{ttl} seconds.
22030 @item @code{port} (default: @code{8081})
22031 Port number used by the HTTP server.
22033 @item @code{host} (default: @code{"localhost"})
22034 Listen on the network interface for @var{host}. The default is to
22035 accept connections from localhost.
22037 @item @code{specifications} (default: @code{#~'()})
22038 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22039 where a specification is an association list
22040 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22041 keys are keywords (@code{#:keyword-example}) as shown in the example
22044 @item @code{use-substitutes?} (default: @code{#f})
22045 This allows using substitutes to avoid building every dependencies of a job
22048 @item @code{one-shot?} (default: @code{#f})
22049 Only evaluate specifications and build derivations once.
22051 @item @code{fallback?} (default: @code{#f})
22052 When substituting a pre-built binary fails, fall back to building
22055 @item @code{cuirass} (default: @code{cuirass})
22056 The Cuirass package to use.
22060 @node Power Management Services
22061 @subsection Power Management Services
22064 @cindex power management with TLP
22065 @subsubheading TLP daemon
22067 The @code{(gnu services pm)} module provides a Guix service definition
22068 for the Linux power management tool TLP.
22070 TLP enables various powersaving modes in userspace and kernel.
22071 Contrary to @code{upower-service}, it is not a passive,
22072 monitoring tool, as it will apply custom settings each time a new power
22073 source is detected. More information can be found at
22074 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22076 @deffn {Scheme Variable} tlp-service-type
22077 The service type for the TLP tool. Its value should be a valid
22078 TLP configuration (see below). To use the default settings, simply
22081 (service tlp-service-type)
22085 By default TLP does not need much configuration but most TLP parameters
22086 can be tweaked using @code{tlp-configuration}.
22088 Each parameter definition is preceded by its type; for example,
22089 @samp{boolean foo} indicates that the @code{foo} parameter
22090 should be specified as a boolean. Types starting with
22091 @code{maybe-} denote parameters that won't show up in TLP config file
22092 when their value is @code{'disabled}.
22094 @c The following documentation was initially generated by
22095 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22096 @c documentation is better, so we shouldn't hesitate to edit below as
22097 @c needed. However if the change you want to make to this documentation
22098 @c can be done in an automated way, it's probably easier to change
22099 @c (generate-documentation) than to make it below and have to deal with
22100 @c the churn as TLP updates.
22102 Available @code{tlp-configuration} fields are:
22104 @deftypevr {@code{tlp-configuration} parameter} package tlp
22109 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22110 Set to true if you wish to enable TLP.
22112 Defaults to @samp{#t}.
22116 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22117 Default mode when no power supply can be detected. Alternatives are AC
22120 Defaults to @samp{"AC"}.
22124 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22125 Number of seconds Linux kernel has to wait after the disk goes idle,
22126 before syncing on AC.
22128 Defaults to @samp{0}.
22132 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22133 Same as @code{disk-idle-ac} but on BAT mode.
22135 Defaults to @samp{2}.
22139 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22140 Dirty pages flushing periodicity, expressed in seconds.
22142 Defaults to @samp{15}.
22146 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22147 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22149 Defaults to @samp{60}.
22153 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22154 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22155 alternatives are powersave and performance. With acpi-cpufreq driver,
22156 alternatives are ondemand, powersave, performance and conservative.
22158 Defaults to @samp{disabled}.
22162 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22163 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22165 Defaults to @samp{disabled}.
22169 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22170 Set the min available frequency for the scaling governor on AC.
22172 Defaults to @samp{disabled}.
22176 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22177 Set the max available frequency for the scaling governor on AC.
22179 Defaults to @samp{disabled}.
22183 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22184 Set the min available frequency for the scaling governor on BAT.
22186 Defaults to @samp{disabled}.
22190 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22191 Set the max available frequency for the scaling governor on BAT.
22193 Defaults to @samp{disabled}.
22197 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22198 Limit the min P-state to control the power dissipation of the CPU, in AC
22199 mode. Values are stated as a percentage of the available performance.
22201 Defaults to @samp{disabled}.
22205 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22206 Limit the max P-state to control the power dissipation of the CPU, in AC
22207 mode. Values are stated as a percentage of the available performance.
22209 Defaults to @samp{disabled}.
22213 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22214 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22216 Defaults to @samp{disabled}.
22220 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22221 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22223 Defaults to @samp{disabled}.
22227 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22228 Enable CPU turbo boost feature on AC mode.
22230 Defaults to @samp{disabled}.
22234 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22235 Same as @code{cpu-boost-on-ac?} on BAT mode.
22237 Defaults to @samp{disabled}.
22241 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22242 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22243 used under light load conditions.
22245 Defaults to @samp{#f}.
22249 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22250 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22252 Defaults to @samp{#t}.
22256 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22257 Enable Linux kernel NMI watchdog.
22259 Defaults to @samp{#f}.
22263 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22264 For Linux kernels with PHC patch applied, change CPU voltages. An
22265 example value would be @samp{"F:V F:V F:V F:V"}.
22267 Defaults to @samp{disabled}.
22271 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
22272 Set CPU performance versus energy saving policy on AC. Alternatives are
22273 performance, normal, powersave.
22275 Defaults to @samp{"performance"}.
22279 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
22280 Same as @code{energy-perf-policy-ac} but on BAT mode.
22282 Defaults to @samp{"powersave"}.
22286 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
22291 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
22292 Hard disk advanced power management level.
22296 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
22297 Same as @code{disk-apm-bat} but on BAT mode.
22301 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
22302 Hard disk spin down timeout. One value has to be specified for each
22303 declared hard disk.
22305 Defaults to @samp{disabled}.
22309 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
22310 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
22312 Defaults to @samp{disabled}.
22316 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
22317 Select IO scheduler for disk devices. One value has to be specified for
22318 each declared hard disk. Example alternatives are cfq, deadline and
22321 Defaults to @samp{disabled}.
22325 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
22326 SATA aggressive link power management (ALPM) level. Alternatives are
22327 min_power, medium_power, max_performance.
22329 Defaults to @samp{"max_performance"}.
22333 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
22334 Same as @code{sata-linkpwr-ac} but on BAT mode.
22336 Defaults to @samp{"min_power"}.
22340 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
22341 Exclude specified SATA host devices for link power management.
22343 Defaults to @samp{disabled}.
22347 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
22348 Enable Runtime Power Management for AHCI controller and disks on AC
22351 Defaults to @samp{disabled}.
22355 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
22356 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
22358 Defaults to @samp{disabled}.
22362 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
22363 Seconds of inactivity before disk is suspended.
22365 Defaults to @samp{15}.
22369 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
22370 PCI Express Active State Power Management level. Alternatives are
22371 default, performance, powersave.
22373 Defaults to @samp{"performance"}.
22377 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
22378 Same as @code{pcie-aspm-ac} but on BAT mode.
22380 Defaults to @samp{"powersave"}.
22384 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
22385 Radeon graphics clock speed level. Alternatives are low, mid, high,
22388 Defaults to @samp{"high"}.
22392 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
22393 Same as @code{radeon-power-ac} but on BAT mode.
22395 Defaults to @samp{"low"}.
22399 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
22400 Radeon dynamic power management method (DPM). Alternatives are battery,
22403 Defaults to @samp{"performance"}.
22407 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
22408 Same as @code{radeon-dpm-state-ac} but on BAT mode.
22410 Defaults to @samp{"battery"}.
22414 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
22415 Radeon DPM performance level. Alternatives are auto, low, high.
22417 Defaults to @samp{"auto"}.
22421 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
22422 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
22424 Defaults to @samp{"auto"}.
22428 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
22429 Wifi power saving mode.
22431 Defaults to @samp{#f}.
22435 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
22436 Same as @code{wifi-power-ac?} but on BAT mode.
22438 Defaults to @samp{#t}.
22442 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
22443 Disable wake on LAN.
22445 Defaults to @samp{#t}.
22449 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
22450 Timeout duration in seconds before activating audio power saving on
22451 Intel HDA and AC97 devices. A value of 0 disables power saving.
22453 Defaults to @samp{0}.
22457 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
22458 Same as @code{sound-powersave-ac} but on BAT mode.
22460 Defaults to @samp{1}.
22464 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
22465 Disable controller in powersaving mode on Intel HDA devices.
22467 Defaults to @samp{#t}.
22471 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
22472 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
22473 powered on again by releasing (and reinserting) the eject lever or by
22474 pressing the disc eject button on newer models.
22476 Defaults to @samp{#f}.
22480 @deftypevr {@code{tlp-configuration} parameter} string bay-device
22481 Name of the optical drive device to power off.
22483 Defaults to @samp{"sr0"}.
22487 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
22488 Runtime Power Management for PCI(e) bus devices. Alternatives are on
22491 Defaults to @samp{"on"}.
22495 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
22496 Same as @code{runtime-pm-ac} but on BAT mode.
22498 Defaults to @samp{"auto"}.
22502 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
22503 Runtime Power Management for all PCI(e) bus devices, except blacklisted
22506 Defaults to @samp{#t}.
22510 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
22511 Exclude specified PCI(e) device addresses from Runtime Power Management.
22513 Defaults to @samp{disabled}.
22517 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
22518 Exclude PCI(e) devices assigned to the specified drivers from Runtime
22523 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
22524 Enable USB autosuspend feature.
22526 Defaults to @samp{#t}.
22530 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
22531 Exclude specified devices from USB autosuspend.
22533 Defaults to @samp{disabled}.
22537 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
22538 Exclude WWAN devices from USB autosuspend.
22540 Defaults to @samp{#t}.
22544 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
22545 Include specified devices into USB autosuspend, even if they are already
22546 excluded by the driver or via @code{usb-blacklist-wwan?}.
22548 Defaults to @samp{disabled}.
22552 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
22553 Enable USB autosuspend before shutdown.
22555 Defaults to @samp{disabled}.
22559 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
22560 Restore radio device state (bluetooth, wifi, wwan) from previous
22561 shutdown on system startup.
22563 Defaults to @samp{#f}.
22568 @cindex CPU frequency scaling with thermald
22569 @subsubheading Thermald daemon
22571 The @code{(gnu services pm)} module provides an interface to
22572 thermald, a CPU frequency scaling service which helps prevent overheating.
22574 @defvr {Scheme Variable} thermald-service-type
22575 This is the service type for
22576 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
22577 Thermal Daemon, which is responsible for controlling the thermal state
22578 of processors and preventing overheating.
22581 @deftp {Data Type} thermald-configuration
22582 Data type representing the configuration of @code{thermald-service-type}.
22585 @item @code{ignore-cpuid-check?} (default: @code{#f})
22586 Ignore cpuid check for supported CPU models.
22588 @item @code{thermald} (default: @var{thermald})
22589 Package object of thermald.
22594 @node Audio Services
22595 @subsection Audio Services
22597 The @code{(gnu services audio)} module provides a service to start MPD
22598 (the Music Player Daemon).
22601 @subsubheading Music Player Daemon
22603 The Music Player Daemon (MPD) is a service that can play music while
22604 being controlled from the local machine or over the network by a variety
22607 The following example shows how one might run @code{mpd} as user
22608 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
22611 (service mpd-service-type
22617 @defvr {Scheme Variable} mpd-service-type
22618 The service type for @command{mpd}
22621 @deftp {Data Type} mpd-configuration
22622 Data type representing the configuration of @command{mpd}.
22625 @item @code{user} (default: @code{"mpd"})
22626 The user to run mpd as.
22628 @item @code{music-dir} (default: @code{"~/Music"})
22629 The directory to scan for music files.
22631 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
22632 The directory to store playlists.
22634 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
22635 The location of the music database.
22637 @item @code{state-file} (default: @code{"~/.mpd/state"})
22638 The location of the file that stores current MPD's state.
22640 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
22641 The location of the sticker database.
22643 @item @code{port} (default: @code{"6600"})
22644 The port to run mpd on.
22646 @item @code{address} (default: @code{"any"})
22647 The address that mpd will bind to. To use a Unix domain socket,
22648 an absolute path can be specified here.
22650 @item @code{outputs} (default: @code{"(list (mpd-output))"})
22651 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
22656 @deftp {Data Type} mpd-output
22657 Data type representing an @command{mpd} audio output.
22660 @item @code{name} (default: @code{"MPD"})
22661 The name of the audio output.
22663 @item @code{type} (default: @code{"pulse"})
22664 The type of audio output.
22666 @item @code{enabled?} (default: @code{#t})
22667 Specifies whether this audio output is enabled when MPD is started. By
22668 default, all audio outputs are enabled. This is just the default
22669 setting when there is no state file; with a state file, the previous
22672 @item @code{tags?} (default: @code{#t})
22673 If set to @code{#f}, then MPD will not send tags to this output. This
22674 is only useful for output plugins that can receive tags, for example the
22675 @code{httpd} output plugin.
22677 @item @code{always-on?} (default: @code{#f})
22678 If set to @code{#t}, then MPD attempts to keep this audio output always
22679 open. This may be useful for streaming servers, when you don’t want to
22680 disconnect all listeners even when playback is accidentally stopped.
22682 @item @code{mixer-type}
22683 This field accepts a symbol that specifies which mixer should be used
22684 for this audio output: the @code{hardware} mixer, the @code{software}
22685 mixer, the @code{null} mixer (allows setting the volume, but with no
22686 effect; this can be used as a trick to implement an external mixer
22687 External Mixer) or no mixer (@code{none}).
22689 @item @code{extra-options} (default: @code{'()"})
22690 An association list of option symbols to string values to be appended to
22691 the audio output configuration.
22696 The following example shows a configuration of @code{mpd} that provides
22697 an HTTP audio streaming output.
22700 (service mpd-service-type
22708 `((encoder . "vorbis")
22709 (port . "8080"))))))))
22713 @node Virtualization Services
22714 @subsection Virtualization services
22716 The @code{(gnu services virtualization)} module provides services for
22717 the libvirt and virtlog daemons, as well as other virtualization-related
22720 @subsubheading Libvirt daemon
22721 @code{libvirtd} is the server side daemon component of the libvirt
22722 virtualization management system. This daemon runs on host servers
22723 and performs required management tasks for virtualized guests.
22725 @deffn {Scheme Variable} libvirt-service-type
22726 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
22727 Its value must be a @code{libvirt-configuration}.
22730 (service libvirt-service-type
22731 (libvirt-configuration
22732 (unix-sock-group "libvirt")
22733 (tls-port "16555")))
22737 @c Auto-generated with (generate-libvirt-documentation)
22738 Available @code{libvirt-configuration} fields are:
22740 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
22745 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
22746 Flag listening for secure TLS connections on the public TCP/IP port.
22747 must set @code{listen} for this to have any effect.
22749 It is necessary to setup a CA and issue server certificates before using
22752 Defaults to @samp{#t}.
22756 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22757 Listen for unencrypted TCP connections on the public TCP/IP port. must
22758 set @code{listen} for this to have any effect.
22760 Using the TCP socket requires SASL authentication by default. Only SASL
22761 mechanisms which support data encryption are allowed. This is
22762 DIGEST_MD5 and GSSAPI (Kerberos5)
22764 Defaults to @samp{#f}.
22768 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
22769 Port for accepting secure TLS connections This can be a port number, or
22772 Defaults to @samp{"16514"}.
22776 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
22777 Port for accepting insecure TCP connections This can be a port number,
22780 Defaults to @samp{"16509"}.
22784 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
22785 IP address or hostname used for client connections.
22787 Defaults to @samp{"0.0.0.0"}.
22791 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
22792 Flag toggling mDNS advertisement of the libvirt service.
22794 Alternatively can disable for all services on a host by stopping the
22797 Defaults to @samp{#f}.
22801 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
22802 Default mDNS advertisement name. This must be unique on the immediate
22805 Defaults to @samp{"Virtualization Host <hostname>"}.
22809 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
22810 UNIX domain socket group ownership. This can be used to allow a
22811 'trusted' set of users access to management capabilities without
22814 Defaults to @samp{"root"}.
22818 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
22819 UNIX socket permissions for the R/O socket. This is used for monitoring
22822 Defaults to @samp{"0777"}.
22826 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
22827 UNIX socket permissions for the R/W socket. Default allows only root.
22828 If PolicyKit is enabled on the socket, the default will change to allow
22829 everyone (eg, 0777)
22831 Defaults to @samp{"0770"}.
22835 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
22836 UNIX socket permissions for the admin socket. Default allows only owner
22837 (root), do not change it unless you are sure to whom you are exposing
22840 Defaults to @samp{"0777"}.
22844 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
22845 The directory in which sockets will be found/created.
22847 Defaults to @samp{"/var/run/libvirt"}.
22851 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
22852 Authentication scheme for UNIX read-only sockets. By default socket
22853 permissions allow anyone to connect
22855 Defaults to @samp{"polkit"}.
22859 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
22860 Authentication scheme for UNIX read-write sockets. By default socket
22861 permissions only allow root. If PolicyKit support was compiled into
22862 libvirt, the default will be to use 'polkit' auth.
22864 Defaults to @samp{"polkit"}.
22868 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
22869 Authentication scheme for TCP sockets. If you don't enable SASL, then
22870 all TCP traffic is cleartext. Don't do this outside of a dev/test
22873 Defaults to @samp{"sasl"}.
22877 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
22878 Authentication scheme for TLS sockets. TLS sockets already have
22879 encryption provided by the TLS layer, and limited authentication is done
22882 It is possible to make use of any SASL authentication mechanism as well,
22883 by using 'sasl' for this option
22885 Defaults to @samp{"none"}.
22889 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
22890 API access control scheme.
22892 By default an authenticated user is allowed access to all APIs. Access
22893 drivers can place restrictions on this.
22895 Defaults to @samp{()}.
22899 @deftypevr {@code{libvirt-configuration} parameter} string key-file
22900 Server key file path. If set to an empty string, then no private key is
22903 Defaults to @samp{""}.
22907 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
22908 Server key file path. If set to an empty string, then no certificate is
22911 Defaults to @samp{""}.
22915 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
22916 Server key file path. If set to an empty string, then no CA certificate
22919 Defaults to @samp{""}.
22923 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
22924 Certificate revocation list path. If set to an empty string, then no
22927 Defaults to @samp{""}.
22931 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
22932 Disable verification of our own server certificates.
22934 When libvirtd starts it performs some sanity checks against its own
22937 Defaults to @samp{#f}.
22941 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
22942 Disable verification of client certificates.
22944 Client certificate verification is the primary authentication mechanism.
22945 Any client which does not present a certificate signed by the CA will be
22948 Defaults to @samp{#f}.
22952 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
22953 Whitelist of allowed x509 Distinguished Name.
22955 Defaults to @samp{()}.
22959 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
22960 Whitelist of allowed SASL usernames. The format for username depends on
22961 the SASL authentication mechanism.
22963 Defaults to @samp{()}.
22967 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
22968 Override the compile time default TLS priority string. The default is
22969 usually "NORMAL" unless overridden at build time. Only set this is it
22970 is desired for libvirt to deviate from the global default settings.
22972 Defaults to @samp{"NORMAL"}.
22976 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
22977 Maximum number of concurrent client connections to allow over all
22980 Defaults to @samp{5000}.
22984 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
22985 Maximum length of queue of connections waiting to be accepted by the
22986 daemon. Note, that some protocols supporting retransmission may obey
22987 this so that a later reattempt at connection succeeds.
22989 Defaults to @samp{1000}.
22993 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
22994 Maximum length of queue of accepted but not yet authenticated clients.
22995 Set this to zero to turn this feature off
22997 Defaults to @samp{20}.
23001 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23002 Number of workers to start up initially.
23004 Defaults to @samp{5}.
23008 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23009 Maximum number of worker threads.
23011 If the number of active clients exceeds @code{min-workers}, then more
23012 threads are spawned, up to max_workers limit. Typically you'd want
23013 max_workers to equal maximum number of clients allowed.
23015 Defaults to @samp{20}.
23019 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23020 Number of priority workers. If all workers from above pool are stuck,
23021 some calls marked as high priority (notably domainDestroy) can be
23022 executed in this pool.
23024 Defaults to @samp{5}.
23028 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23029 Total global limit on concurrent RPC calls.
23031 Defaults to @samp{20}.
23035 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23036 Limit on concurrent requests from a single client connection. To avoid
23037 one client monopolizing the server this should be a small fraction of
23038 the global max_requests and max_workers parameter.
23040 Defaults to @samp{5}.
23044 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23045 Same as @code{min-workers} but for the admin interface.
23047 Defaults to @samp{1}.
23051 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23052 Same as @code{max-workers} but for the admin interface.
23054 Defaults to @samp{5}.
23058 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23059 Same as @code{max-clients} but for the admin interface.
23061 Defaults to @samp{5}.
23065 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23066 Same as @code{max-queued-clients} but for the admin interface.
23068 Defaults to @samp{5}.
23072 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23073 Same as @code{max-client-requests} but for the admin interface.
23075 Defaults to @samp{5}.
23079 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23080 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23082 Defaults to @samp{3}.
23086 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23089 A filter allows to select a different logging level for a given category
23090 of logs The format for a filter is one of:
23101 where @code{name} is a string which is matched against the category
23102 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23103 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23104 be a substring of the full category name, in order to match multiple
23105 similar categories), the optional "+" prefix tells libvirt to log stack
23106 trace for each message matching name, and @code{x} is the minimal level
23107 where matching messages should be logged:
23124 Multiple filters can be defined in a single filters statement, they just
23125 need to be separated by spaces.
23127 Defaults to @samp{"3:remote 4:event"}.
23131 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23134 An output is one of the places to save logging information. The format
23135 for an output can be:
23139 output goes to stderr
23141 @item x:syslog:name
23142 use syslog for the output and use the given name as the ident
23144 @item x:file:file_path
23145 output to a file, with the given filepath
23148 output to journald logging system
23152 In all case the x prefix is the minimal level, acting as a filter
23169 Multiple outputs can be defined, they just need to be separated by
23172 Defaults to @samp{"3:stderr"}.
23176 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23177 Allows usage of the auditing subsystem to be altered
23181 0: disable all auditing
23184 1: enable auditing, only if enabled on host
23187 2: enable auditing, and exit if disabled on host.
23191 Defaults to @samp{1}.
23195 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23196 Send audit messages via libvirt logging infrastructure.
23198 Defaults to @samp{#f}.
23202 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23203 Host UUID. UUID must not have all digits be the same.
23205 Defaults to @samp{""}.
23209 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23210 Source to read host UUID.
23214 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23217 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23221 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23224 Defaults to @samp{"smbios"}.
23228 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23229 A keepalive message is sent to a client after @code{keepalive_interval}
23230 seconds of inactivity to check if the client is still responding. If
23231 set to -1, libvirtd will never send keepalive requests; however clients
23232 can still send them and the daemon will send responses.
23234 Defaults to @samp{5}.
23238 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23239 Maximum number of keepalive messages that are allowed to be sent to the
23240 client without getting any response before the connection is considered
23243 In other words, the connection is automatically closed approximately
23244 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23245 the last message received from the client. When @code{keepalive-count}
23246 is set to 0, connections will be automatically closed after
23247 @code{keepalive-interval} seconds of inactivity without sending any
23248 keepalive messages.
23250 Defaults to @samp{5}.
23254 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23255 Same as above but for admin interface.
23257 Defaults to @samp{5}.
23261 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23262 Same as above but for admin interface.
23264 Defaults to @samp{5}.
23268 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
23269 Timeout for Open vSwitch calls.
23271 The @code{ovs-vsctl} utility is used for the configuration and its
23272 timeout option is set by default to 5 seconds to avoid potential
23273 infinite waits blocking libvirt.
23275 Defaults to @samp{5}.
23279 @c %end of autogenerated docs
23281 @subsubheading Virtlog daemon
23282 The virtlogd service is a server side daemon component of libvirt that is
23283 used to manage logs from virtual machine consoles.
23285 This daemon is not used directly by libvirt client applications, rather it
23286 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
23287 standalone daemon, the main @code{libvirtd} daemon can be restarted without
23288 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
23289 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
23291 @deffn {Scheme Variable} virtlog-service-type
23292 This is the type of the virtlog daemon.
23293 Its value must be a @code{virtlog-configuration}.
23296 (service virtlog-service-type
23297 (virtlog-configuration
23298 (max-clients 1000)))
23302 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
23303 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23305 Defaults to @samp{3}.
23309 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
23312 A filter allows to select a different logging level for a given category
23313 of logs The format for a filter is one of:
23324 where @code{name} is a string which is matched against the category
23325 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23326 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23327 be a substring of the full category name, in order to match multiple
23328 similar categories), the optional "+" prefix tells libvirt to log stack
23329 trace for each message matching name, and @code{x} is the minimal level
23330 where matching messages should be logged:
23347 Multiple filters can be defined in a single filters statement, they just
23348 need to be separated by spaces.
23350 Defaults to @samp{"3:remote 4:event"}.
23354 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
23357 An output is one of the places to save logging information The format
23358 for an output can be:
23362 output goes to stderr
23364 @item x:syslog:name
23365 use syslog for the output and use the given name as the ident
23367 @item x:file:file_path
23368 output to a file, with the given filepath
23371 output to journald logging system
23375 In all case the x prefix is the minimal level, acting as a filter
23392 Multiple outputs can be defined, they just need to be separated by
23395 Defaults to @samp{"3:stderr"}.
23399 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
23400 Maximum number of concurrent client connections to allow over all
23403 Defaults to @samp{1024}.
23407 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
23408 Maximum file size before rolling over.
23410 Defaults to @samp{2MB}
23414 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
23415 Maximum number of backup files to keep.
23417 Defaults to @samp{3}
23421 @subsubheading Transparent Emulation with QEMU
23424 @cindex @code{binfmt_misc}
23425 @code{qemu-binfmt-service-type} provides support for transparent
23426 emulation of program binaries built for different architectures---e.g.,
23427 it allows you to transparently execute an ARMv7 program on an x86_64
23428 machine. It achieves this by combining the @uref{https://www.qemu.org,
23429 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
23431 @defvr {Scheme Variable} qemu-binfmt-service-type
23432 This is the type of the QEMU/binfmt service for transparent emulation.
23433 Its value must be a @code{qemu-binfmt-configuration} object, which
23434 specifies the QEMU package to use as well as the architecture we want to
23438 (service qemu-binfmt-service-type
23439 (qemu-binfmt-configuration
23440 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
23443 In this example, we enable transparent emulation for the ARM and aarch64
23444 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
23445 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
23446 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
23449 @deftp {Data Type} qemu-binfmt-configuration
23450 This is the configuration for the @code{qemu-binfmt} service.
23453 @item @code{platforms} (default: @code{'()})
23454 The list of emulated QEMU platforms. Each item must be a @dfn{platform
23455 object} as returned by @code{lookup-qemu-platforms} (see below).
23457 @item @code{guix-support?} (default: @code{#f})
23458 When it is true, QEMU and all its dependencies are added to the build
23459 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
23460 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
23461 handlers to be used within the build environment, which in turn means
23462 that you can transparently build programs for another architecture.
23464 For example, let's suppose you're on an x86_64 machine and you have this
23468 (service qemu-binfmt-service-type
23469 (qemu-binfmt-configuration
23470 (platforms (lookup-qemu-platforms "arm"))
23471 (guix-support? #t)))
23477 guix build -s armhf-linux inkscape
23481 and it will build Inkscape for ARMv7 @emph{as if it were a native
23482 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
23483 if you'd like to test a package build for an architecture you don't have
23486 @item @code{qemu} (default: @code{qemu})
23487 The QEMU package to use.
23491 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
23492 Return the list of QEMU platform objects corresponding to
23493 @var{platforms}@dots{}. @var{platforms} must be a list of strings
23494 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
23495 @code{"mips64el"}, and so on.
23498 @deffn {Scheme Procedure} qemu-platform? @var{obj}
23499 Return true if @var{obj} is a platform object.
23502 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
23503 Return the name of @var{platform}---a string such as @code{"arm"}.
23506 @node Version Control Services
23507 @subsection Version Control Services
23509 The @code{(gnu services version-control)} module provides a service to
23510 allow remote access to local Git repositories. There are three options:
23511 the @code{git-daemon-service}, which provides access to repositories via
23512 the @code{git://} unsecured TCP-based protocol, extending the
23513 @code{nginx} web server to proxy some requests to
23514 @code{git-http-backend}, or providing a web interface with
23515 @code{cgit-service-type}.
23517 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
23519 Return a service that runs @command{git daemon}, a simple TCP server to
23520 expose repositories over the Git protocol for anonymous access.
23522 The optional @var{config} argument should be a
23523 @code{<git-daemon-configuration>} object, by default it allows read-only
23524 access to exported@footnote{By creating the magic file
23525 "git-daemon-export-ok" in the repository directory.} repositories under
23530 @deftp {Data Type} git-daemon-configuration
23531 Data type representing the configuration for @code{git-daemon-service}.
23534 @item @code{package} (default: @var{git})
23535 Package object of the Git distributed version control system.
23537 @item @code{export-all?} (default: @var{#f})
23538 Whether to allow access for all Git repositories, even if they do not
23539 have the @file{git-daemon-export-ok} file.
23541 @item @code{base-path} (default: @file{/srv/git})
23542 Whether to remap all the path requests as relative to the given path.
23543 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
23544 then if you later try to pull @code{git://example.com/hello.git}, git
23545 daemon will interpret the path as @code{/srv/git/hello.git}.
23547 @item @code{user-path} (default: @var{#f})
23548 Whether to allow @code{~user} notation to be used in requests. When
23549 specified with empty string, requests to @code{git://host/~alice/foo} is
23550 taken as a request to access @code{foo} repository in the home directory
23551 of user @code{alice}. If @var{(user-path "path")} is specified, the
23552 same request is taken as a request to access @code{path/foo} repository
23553 in the home directory of user @code{alice}.
23555 @item @code{listen} (default: @var{'()})
23556 Whether to listen on specific IP addresses or hostnames, defaults to
23559 @item @code{port} (default: @var{#f})
23560 Whether to listen on an alternative port, which defaults to 9418.
23562 @item @code{whitelist} (default: @var{'()})
23563 If not empty, only allow access to this list of directories.
23565 @item @code{extra-options} (default: @var{'()})
23566 Extra options will be passed to @code{git daemon}, please run
23567 @command{man git-daemon} for more information.
23572 The @code{git://} protocol lacks authentication. When you pull from a
23573 repository fetched via @code{git://}, you don't know whether the data you
23574 receive was modified or is even coming from the specified host, and your
23575 connection is subject to eavesdropping. It's better to use an authenticated
23576 and encrypted transport, such as @code{https}. Although Git allows you
23577 to serve repositories using unsophisticated file-based web servers,
23578 there is a faster protocol implemented by the @code{git-http-backend}
23579 program. This program is the back-end of a proper Git web service. It
23580 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
23581 on running the necessary @code{fcgiwrap} daemon.
23583 Guix has a separate configuration data type for serving Git repositories
23586 @deftp {Data Type} git-http-configuration
23587 Data type representing the configuration for @code{git-http-service}.
23590 @item @code{package} (default: @var{git})
23591 Package object of the Git distributed version control system.
23593 @item @code{git-root} (default: @file{/srv/git})
23594 Directory containing the Git repositories to expose to the world.
23596 @item @code{export-all?} (default: @var{#f})
23597 Whether to expose access for all Git repositories in @var{git-root},
23598 even if they do not have the @file{git-daemon-export-ok} file.
23600 @item @code{uri-path} (default: @file{/git/})
23601 Path prefix for Git access. With the default @code{/git/} prefix, this
23602 will map @code{http://@var{server}/git/@var{repo}.git} to
23603 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
23604 with this prefix are not passed on to this Git instance.
23606 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
23607 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
23612 There is no @code{git-http-service-type}, currently; instead you can
23613 create an @code{nginx-location-configuration} from a
23614 @code{git-http-configuration} and then add that location to a web
23617 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
23618 [config=(git-http-configuration)]
23619 Compute an @code{nginx-location-configuration} that corresponds to the
23620 given Git http configuration. An example nginx service definition to
23621 serve the default @file{/srv/git} over HTTPS might be:
23624 (service nginx-service-type
23625 (nginx-configuration
23628 (nginx-server-configuration
23629 (listen '("443 ssl"))
23630 (server-name "git.my-host.org")
23632 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
23633 (ssl-certificate-key
23634 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
23637 (git-http-nginx-location-configuration
23638 (git-http-configuration (uri-path "/"))))))))))
23641 This example assumes that you are using Let's Encrypt to get your TLS
23642 certificate. @xref{Certificate Services}. The default @code{certbot}
23643 service will redirect all HTTP traffic on @code{git.my-host.org} to
23644 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
23645 system services. @xref{Web Services}.
23648 @subsubheading Cgit Service
23650 @cindex Cgit service
23651 @cindex Git, web interface
23652 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
23653 repositories written in C.
23655 The following example will configure the service with default values.
23656 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
23659 (service cgit-service-type)
23662 The @code{file-object} type designates either a file-like object
23663 (@pxref{G-Expressions, file-like objects}) or a string.
23665 @c %start of fragment
23667 Available @code{cgit-configuration} fields are:
23669 @deftypevr {@code{cgit-configuration} parameter} package package
23674 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
23675 NGINX configuration.
23679 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
23680 Specifies a command which will be invoked to format the content of about
23681 pages (both top-level and for each repository).
23683 Defaults to @samp{""}.
23687 @deftypevr {@code{cgit-configuration} parameter} string agefile
23688 Specifies a path, relative to each repository path, which can be used to
23689 specify the date and time of the youngest commit in the repository.
23691 Defaults to @samp{""}.
23695 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
23696 Specifies a command that will be invoked for authenticating repository
23699 Defaults to @samp{""}.
23703 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
23704 Flag which, when set to @samp{age}, enables date ordering in the branch
23705 ref list, and when set @samp{name} enables ordering by branch name.
23707 Defaults to @samp{"name"}.
23711 @deftypevr {@code{cgit-configuration} parameter} string cache-root
23712 Path used to store the cgit cache entries.
23714 Defaults to @samp{"/var/cache/cgit"}.
23718 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
23719 Number which specifies the time-to-live, in minutes, for the cached
23720 version of repository pages accessed with a fixed SHA1.
23722 Defaults to @samp{-1}.
23726 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
23727 Number which specifies the time-to-live, in minutes, for the cached
23728 version of repository pages accessed without a fixed SHA1.
23730 Defaults to @samp{5}.
23734 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
23735 Number which specifies the time-to-live, in minutes, for the cached
23736 version of the repository summary page.
23738 Defaults to @samp{5}.
23742 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
23743 Number which specifies the time-to-live, in minutes, for the cached
23744 version of the repository index page.
23746 Defaults to @samp{5}.
23750 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
23751 Number which specifies the time-to-live, in minutes, for the result of
23752 scanning a path for Git repositories.
23754 Defaults to @samp{15}.
23758 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23759 Number which specifies the time-to-live, in minutes, for the cached
23760 version of the repository about page.
23762 Defaults to @samp{15}.
23766 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
23767 Number which specifies the time-to-live, in minutes, for the cached
23768 version of snapshots.
23770 Defaults to @samp{5}.
23774 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
23775 The maximum number of entries in the cgit cache. When set to @samp{0},
23776 caching is disabled.
23778 Defaults to @samp{0}.
23782 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
23783 Sort items in the repo list case sensitively.
23785 Defaults to @samp{#t}.
23789 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
23790 List of common prefixes which, when combined with a repository URL,
23791 generates valid clone URLs for the repository.
23793 Defaults to @samp{()}.
23797 @deftypevr {@code{cgit-configuration} parameter} list clone-url
23798 List of @code{clone-url} templates.
23800 Defaults to @samp{()}.
23804 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
23805 Command which will be invoked to format commit messages.
23807 Defaults to @samp{""}.
23811 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
23812 Flag which, when set to @samp{date}, enables strict date ordering in the
23813 commit log, and when set to @samp{topo} enables strict topological
23816 Defaults to @samp{"git log"}.
23820 @deftypevr {@code{cgit-configuration} parameter} file-object css
23821 URL which specifies the css document to include in all cgit pages.
23823 Defaults to @samp{"/share/cgit/cgit.css"}.
23827 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
23828 Specifies a command which will be invoked to format names and email
23829 address of committers, authors, and taggers, as represented in various
23830 places throughout the cgit interface.
23832 Defaults to @samp{""}.
23836 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
23837 Flag which, when set to @samp{#t}, will make cgit generate a HTML
23838 fragment suitable for embedding in other HTML pages.
23840 Defaults to @samp{#f}.
23844 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
23845 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
23846 commit history graph to the left of the commit messages in the
23847 repository log page.
23849 Defaults to @samp{#f}.
23853 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
23854 Flag which, when set to @samp{#t}, allows all filter settings to be
23855 overridden in repository-specific cgitrc files.
23857 Defaults to @samp{#f}.
23861 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
23862 Flag which, when set to @samp{#t}, allows users to follow a file in the
23865 Defaults to @samp{#f}.
23869 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
23870 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
23873 Defaults to @samp{#t}.
23877 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
23878 Flag which, when set to @samp{#t}, will make cgit generate extra links
23879 "summary", "commit", "tree" for each repo in the repository index.
23881 Defaults to @samp{#f}.
23885 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
23886 Flag which, when set to @samp{#t}, will make cgit display the owner of
23887 each repo in the repository index.
23889 Defaults to @samp{#t}.
23893 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
23894 Flag which, when set to @samp{#t}, will make cgit print the number of
23895 modified files for each commit on the repository log page.
23897 Defaults to @samp{#f}.
23901 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
23902 Flag which, when set to @samp{#t}, will make cgit print the number of
23903 added and removed lines for each commit on the repository log page.
23905 Defaults to @samp{#f}.
23909 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
23910 Flag which, when set to @code{#t}, will make cgit display remote
23911 branches in the summary and refs views.
23913 Defaults to @samp{#f}.
23917 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
23918 Flag which, when set to @code{1}, will make cgit use the subject of the
23919 parent commit as link text when generating links to parent commits in
23922 Defaults to @samp{#f}.
23926 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
23927 Flag which, when set to @samp{#t}, will make cgit use the subject of the
23928 parent commit as link text when generating links to parent commits in
23931 Defaults to @samp{#f}.
23935 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
23936 Flag which, when set to @samp{#t}, will make cgit generate linenumber
23937 links for plaintext blobs printed in the tree view.
23939 Defaults to @samp{#t}.
23943 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
23944 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
23945 set any repo specific settings.
23947 Defaults to @samp{#f}.
23951 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
23952 URL used as link to a shortcut icon for cgit.
23954 Defaults to @samp{"/favicon.ico"}.
23958 @deftypevr {@code{cgit-configuration} parameter} string footer
23959 The content of the file specified with this option will be included
23960 verbatim at the bottom of all pages (i.e.@: it replaces the standard
23961 "generated by..."@: message).
23963 Defaults to @samp{""}.
23967 @deftypevr {@code{cgit-configuration} parameter} string head-include
23968 The content of the file specified with this option will be included
23969 verbatim in the HTML HEAD section on all pages.
23971 Defaults to @samp{""}.
23975 @deftypevr {@code{cgit-configuration} parameter} string header
23976 The content of the file specified with this option will be included
23977 verbatim at the top of all pages.
23979 Defaults to @samp{""}.
23983 @deftypevr {@code{cgit-configuration} parameter} file-object include
23984 Name of a configfile to include before the rest of the current config-
23987 Defaults to @samp{""}.
23991 @deftypevr {@code{cgit-configuration} parameter} string index-header
23992 The content of the file specified with this option will be included
23993 verbatim above the repository index.
23995 Defaults to @samp{""}.
23999 @deftypevr {@code{cgit-configuration} parameter} string index-info
24000 The content of the file specified with this option will be included
24001 verbatim below the heading on the repository index page.
24003 Defaults to @samp{""}.
24007 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24008 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24009 in the servers timezone.
24011 Defaults to @samp{#f}.
24015 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24016 URL which specifies the source of an image which will be used as a logo
24019 Defaults to @samp{"/share/cgit/cgit.png"}.
24023 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24024 URL loaded when clicking on the cgit logo image.
24026 Defaults to @samp{""}.
24030 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24031 Command which will be invoked to format the Owner column of the main
24034 Defaults to @samp{""}.
24038 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24039 Number of items to display in atom feeds view.
24041 Defaults to @samp{10}.
24045 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24046 Number of entries to list per page in "log" view.
24048 Defaults to @samp{50}.
24052 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24053 Number of commit message characters to display in "log" view.
24055 Defaults to @samp{80}.
24059 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24060 Specifies the number of entries to list per page on the repository index
24063 Defaults to @samp{50}.
24067 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24068 Specifies the maximum number of repo description characters to display
24069 on the repository index page.
24071 Defaults to @samp{80}.
24075 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24076 Specifies the maximum size of a blob to display HTML for in KBytes.
24078 Defaults to @samp{0}.
24082 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24083 Maximum statistics period. Valid values are @samp{week},@samp{month},
24084 @samp{quarter} and @samp{year}.
24086 Defaults to @samp{""}.
24090 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24091 Mimetype for the specified filename extension.
24093 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24094 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24095 "image/png") (svg "image/svg+xml"))}.
24099 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24100 Specifies the file to use for automatic mimetype lookup.
24102 Defaults to @samp{""}.
24106 @deftypevr {@code{cgit-configuration} parameter} string module-link
24107 Text which will be used as the formatstring for a hyperlink when a
24108 submodule is printed in a directory listing.
24110 Defaults to @samp{""}.
24114 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24115 If set to the value @samp{#t} caching will be disabled.
24117 Defaults to @samp{#f}.
24121 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24122 If set to @samp{#t} showing full author email addresses will be
24125 Defaults to @samp{#f}.
24129 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24130 Flag which, when set to @samp{#t}, will make cgit omit the standard
24131 header on all pages.
24133 Defaults to @samp{#f}.
24137 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24138 A list of subdirectories inside of @code{repository-directory}, relative
24139 to it, that should loaded as Git repositories. An empty list means that
24140 all subdirectories will be loaded.
24142 Defaults to @samp{()}.
24146 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24147 Text which will be used as default value for @code{cgit-repo-readme}.
24149 Defaults to @samp{""}.
24153 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24154 If set to @code{#t} and @code{repository-directory} is enabled, if any
24155 repositories are found with a suffix of @code{.git}, this suffix will be
24156 removed for the URL and name.
24158 Defaults to @samp{#f}.
24162 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24163 Maximum number of files to consider when detecting renames.
24165 Defaults to @samp{-1}.
24169 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24170 The way in which repositories in each section are sorted.
24172 Defaults to @samp{""}.
24176 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24177 Text used as content for the @code{robots} meta-tag.
24179 Defaults to @samp{("noindex" "nofollow")}.
24183 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24184 Text printed below the heading on the repository index page.
24186 Defaults to @samp{"a fast webinterface for the git dscm"}.
24190 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24191 The content of the file specified with this option will be included
24192 verbatim below thef "about" link on the repository index page.
24194 Defaults to @samp{""}.
24198 @deftypevr {@code{cgit-configuration} parameter} string root-title
24199 Text printed as heading on the repository index page.
24201 Defaults to @samp{""}.
24205 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24206 If set to @samp{#t} and repository-directory is enabled,
24207 repository-directory will recurse into directories whose name starts
24208 with a period. Otherwise, repository-directory will stay away from such
24209 directories, considered as "hidden". Note that this does not apply to
24210 the ".git" directory in non-bare repos.
24212 Defaults to @samp{#f}.
24216 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24217 Text which specifies the default set of snapshot formats that cgit
24218 generates links for.
24220 Defaults to @samp{()}.
24224 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24225 Name of the directory to scan for repositories (represents
24228 Defaults to @samp{"/srv/git"}.
24232 @deftypevr {@code{cgit-configuration} parameter} string section
24233 The name of the current repository section - all repositories defined
24234 after this option will inherit the current section name.
24236 Defaults to @samp{""}.
24240 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24241 Flag which, when set to @samp{1}, will sort the sections on the
24242 repository listing by name.
24244 Defaults to @samp{""}.
24248 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24249 A number which, if defined prior to repository-directory, specifies how
24250 many path elements from each repo path to use as a default section name.
24252 Defaults to @samp{0}.
24256 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24257 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24260 Defaults to @samp{#f}.
24264 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
24265 Specifies a command which will be invoked to format plaintext blobs in
24268 Defaults to @samp{""}.
24272 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
24273 Specifies the number of branches to display in the repository "summary"
24276 Defaults to @samp{10}.
24280 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
24281 Specifies the number of log entries to display in the repository
24284 Defaults to @samp{10}.
24288 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
24289 Specifies the number of tags to display in the repository "summary"
24292 Defaults to @samp{10}.
24296 @deftypevr {@code{cgit-configuration} parameter} string strict-export
24297 Filename which, if specified, needs to be present within the repository
24298 for cgit to allow access to that repository.
24300 Defaults to @samp{""}.
24304 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
24305 URL which, if specified, will be used as root for all cgit links.
24307 Defaults to @samp{"/"}.
24311 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
24312 A list of @dfn{cgit-repo} records to use with config.
24314 Defaults to @samp{()}.
24316 Available @code{repository-cgit-configuration} fields are:
24318 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
24319 A mask of snapshot formats for this repo that cgit generates links for,
24320 restricted by the global @code{snapshots} setting.
24322 Defaults to @samp{()}.
24326 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
24327 Override the default @code{source-filter}.
24329 Defaults to @samp{""}.
24333 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
24334 The relative URL used to access the repository.
24336 Defaults to @samp{""}.
24340 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
24341 Override the default @code{about-filter}.
24343 Defaults to @samp{""}.
24347 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
24348 Flag which, when set to @samp{age}, enables date ordering in the branch
24349 ref list, and when set to @samp{name} enables ordering by branch name.
24351 Defaults to @samp{""}.
24355 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
24356 A list of URLs which can be used to clone repo.
24358 Defaults to @samp{()}.
24362 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
24363 Override the default @code{commit-filter}.
24365 Defaults to @samp{""}.
24369 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
24370 Flag which, when set to @samp{date}, enables strict date ordering in the
24371 commit log, and when set to @samp{topo} enables strict topological
24374 Defaults to @samp{""}.
24378 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
24379 The name of the default branch for this repository. If no such branch
24380 exists in the repository, the first branch name (when sorted) is used as
24381 default instead. By default branch pointed to by HEAD, or "master" if
24382 there is no suitable HEAD.
24384 Defaults to @samp{""}.
24388 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
24389 The value to show as repository description.
24391 Defaults to @samp{""}.
24395 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
24396 The value to show as repository homepage.
24398 Defaults to @samp{""}.
24402 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
24403 Override the default @code{email-filter}.
24405 Defaults to @samp{""}.
24409 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
24410 A flag which can be used to disable the global setting
24411 @code{enable-commit-graph?}.
24413 Defaults to @samp{disabled}.
24417 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
24418 A flag which can be used to disable the global setting
24419 @code{enable-log-filecount?}.
24421 Defaults to @samp{disabled}.
24425 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
24426 A flag which can be used to disable the global setting
24427 @code{enable-log-linecount?}.
24429 Defaults to @samp{disabled}.
24433 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
24434 Flag which, when set to @code{#t}, will make cgit display remote
24435 branches in the summary and refs views.
24437 Defaults to @samp{disabled}.
24441 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
24442 A flag which can be used to override the global setting
24443 @code{enable-subject-links?}.
24445 Defaults to @samp{disabled}.
24449 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
24450 A flag which can be used to override the global setting
24451 @code{enable-html-serving?}.
24453 Defaults to @samp{disabled}.
24457 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
24458 Flag which, when set to @code{#t}, hides the repository from the
24461 Defaults to @samp{#f}.
24465 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
24466 Flag which, when set to @samp{#t}, ignores the repository.
24468 Defaults to @samp{#f}.
24472 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
24473 URL which specifies the source of an image which will be used as a logo
24474 on this repo’s pages.
24476 Defaults to @samp{""}.
24480 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
24481 URL loaded when clicking on the cgit logo image.
24483 Defaults to @samp{""}.
24487 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
24488 Override the default @code{owner-filter}.
24490 Defaults to @samp{""}.
24494 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
24495 Text which will be used as the formatstring for a hyperlink when a
24496 submodule is printed in a directory listing. The arguments for the
24497 formatstring are the path and SHA1 of the submodule commit.
24499 Defaults to @samp{""}.
24503 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
24504 Text which will be used as the formatstring for a hyperlink when a
24505 submodule with the specified subdirectory path is printed in a directory
24508 Defaults to @samp{()}.
24512 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
24513 Override the default maximum statistics period.
24515 Defaults to @samp{""}.
24519 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
24520 The value to show as repository name.
24522 Defaults to @samp{""}.
24526 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
24527 A value used to identify the owner of the repository.
24529 Defaults to @samp{""}.
24533 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
24534 An absolute path to the repository directory.
24536 Defaults to @samp{""}.
24540 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
24541 A path (relative to repo) which specifies a file to include verbatim as
24542 the "About" page for this repo.
24544 Defaults to @samp{""}.
24548 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
24549 The name of the current repository section - all repositories defined
24550 after this option will inherit the current section name.
24552 Defaults to @samp{""}.
24556 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
24557 Extra options will be appended to cgitrc file.
24559 Defaults to @samp{()}.
24565 @deftypevr {@code{cgit-configuration} parameter} list extra-options
24566 Extra options will be appended to cgitrc file.
24568 Defaults to @samp{()}.
24573 @c %end of fragment
24575 However, it could be that you just want to get a @code{cgitrc} up and
24576 running. In that case, you can pass an @code{opaque-cgit-configuration}
24577 as a record to @code{cgit-service-type}. As its name indicates, an
24578 opaque configuration does not have easy reflective capabilities.
24580 Available @code{opaque-cgit-configuration} fields are:
24582 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
24586 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
24587 The contents of the @code{cgitrc}, as a string.
24590 For example, if your @code{cgitrc} is just the empty string, you
24591 could instantiate a cgit service like this:
24594 (service cgit-service-type
24595 (opaque-cgit-configuration
24599 @subsubheading Gitolite Service
24601 @cindex Gitolite service
24602 @cindex Git, hosting
24603 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
24604 repositories on a central server.
24606 Gitolite can handle multiple repositories and users, and supports flexible
24607 configuration of the permissions for the users on the repositories.
24609 The following example will configure Gitolite using the default @code{git}
24610 user, and the provided SSH public key.
24613 (service gitolite-service-type
24614 (gitolite-configuration
24615 (admin-pubkey (plain-file
24617 "ssh-rsa AAAA... guix@@example.com"))))
24620 Gitolite is configured through a special admin repository which you can clone,
24621 for example, if you setup Gitolite on @code{example.com}, you would run the
24622 following command to clone the admin repository.
24625 git clone git@@example.com:gitolite-admin
24628 When the Gitolite service is activated, the provided @code{admin-pubkey} will
24629 be inserted in to the @file{keydir} directory in the gitolite-admin
24630 repository. If this results in a change in the repository, it will be
24631 committed using the message ``gitolite setup by GNU Guix''.
24633 @deftp {Data Type} gitolite-configuration
24634 Data type representing the configuration for @code{gitolite-service-type}.
24637 @item @code{package} (default: @var{gitolite})
24638 Gitolite package to use.
24640 @item @code{user} (default: @var{git})
24641 User to use for Gitolite. This will be user that you use when accessing
24644 @item @code{group} (default: @var{git})
24645 Group to use for Gitolite.
24647 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
24648 Directory in which to store the Gitolite configuration and repositories.
24650 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
24651 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
24652 representing the configuration for Gitolite.
24654 @item @code{admin-pubkey} (default: @var{#f})
24655 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
24656 setup Gitolite. This will be inserted in to the @file{keydir} directory
24657 within the gitolite-admin repository.
24659 To specify the SSH key as a string, use the @code{plain-file} function.
24662 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
24668 @deftp {Data Type} gitolite-rc-file
24669 Data type representing the Gitolite RC file.
24672 @item @code{umask} (default: @code{#o0077})
24673 This controls the permissions Gitolite sets on the repositories and their
24676 A value like @code{#o0027} will give read access to the group used by Gitolite
24677 (by default: @code{git}). This is necessary when using Gitolite with software
24678 like cgit or gitweb.
24680 @item @code{git-config-keys} (default: @code{""})
24681 Gitolite allows you to set git config values using the "config" keyword. This
24682 setting allows control over the config keys to accept.
24684 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
24685 Set the role names allowed to be used by users running the perms command.
24687 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
24688 This setting controls the commands and features to enable within Gitolite.
24694 @node Game Services
24695 @subsection Game Services
24697 @subsubheading The Battle for Wesnoth Service
24699 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
24700 based tactical strategy game, with several single player campaigns, and
24701 multiplayer games (both networked and local).
24703 @defvar {Scheme Variable} wesnothd-service-type
24704 Service type for the wesnothd service. Its value must be a
24705 @code{wesnothd-configuration} object. To run wesnothd in the default
24706 configuration, instantiate it as:
24709 (service wesnothd-service-type)
24713 @deftp {Data Type} wesnothd-configuration
24714 Data type representing the configuration of @command{wesnothd}.
24717 @item @code{package} (default: @code{wesnoth-server})
24718 The wesnoth server package to use.
24720 @item @code{port} (default: @code{15000})
24721 The port to bind the server to.
24726 @node PAM Mount Service
24727 @subsection PAM Mount Service
24730 The @code{(gnu services pam-mount)} module provides a service allowing
24731 users to mount volumes when they log in. It should be able to mount any
24732 volume format supported by the system.
24734 @defvar {Scheme Variable} pam-mount-service-type
24735 Service type for PAM Mount support.
24738 @deftp {Data Type} pam-mount-configuration
24739 Data type representing the configuration of PAM Mount.
24741 It takes the following parameters:
24745 The configuration rules that will be used to generate
24746 @file{/etc/security/pam_mount.conf.xml}.
24748 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
24749 Guile Reference Manual}), and the the default ones don't mount anything
24750 for anyone at login:
24753 `((debug (@@ (enable "0")))
24754 (mntoptions (@@ (allow ,(string-join
24755 '("nosuid" "nodev" "loop"
24756 "encryption" "fsck" "nonempty"
24757 "allow_root" "allow_other")
24759 (mntoptions (@@ (require "nosuid,nodev")))
24760 (logout (@@ (wait "0")
24764 (mkmountpoint (@@ (enable "1")
24768 Some @code{volume} elements must be added to automatically mount volumes
24769 at login. Here's an example allowing the user @code{alice} to mount her
24770 encrypted @code{HOME} directory and allowing the user @code{bob} to mount
24771 the partition where he stores his data:
24774 (define pam-mount-rules
24775 `((debug (@@ (enable "0")))
24776 (volume (@@ (user "alice")
24779 (mountpoint "/home/alice")))
24780 (volume (@@ (user "bob")
24783 (mountpoint "/home/bob/data")
24784 (options "defaults,autodefrag,compress")))
24785 (mntoptions (@@ (allow ,(string-join
24786 '("nosuid" "nodev" "loop"
24787 "encryption" "fsck" "nonempty"
24788 "allow_root" "allow_other")
24790 (mntoptions (@@ (require "nosuid,nodev")))
24791 (logout (@@ (wait "0")
24795 (mkmountpoint (@@ (enable "1")
24796 (remove "true")))))
24798 (service pam-mount-service-type
24799 (pam-mount-configuration
24800 (rules pam-mount-rules)))
24803 The complete list of possible options can be found in the man page for
24804 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
24809 @node Guix Services
24810 @subsection Guix Services
24812 @subsubheading Guix Data Service
24813 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
24814 and provides data about GNU Guix. This includes information about
24815 packages, derivations and lint warnings.
24817 The data is stored in a PostgreSQL database, and available through a web
24820 @defvar {Scheme Variable} guix-data-service-type
24821 Service type for the Guix Data Service. Its value must be a
24822 @code{guix-data-service-configuration} object. The service optionally
24823 extends the getmail service, as the guix-commits mailing list is used to
24824 find out about changes in the Guix git repository.
24827 @deftp {Data Type} guix-data-service-configuration
24828 Data type representing the configuration of the Guix Data Service.
24831 @item @code{package} (default: @code{guix-data-service})
24832 The Guix Data Service package to use.
24834 @item @code{user} (default: @code{"guix-data-service"})
24835 The system user to run the service as.
24837 @item @code{group} (default: @code{"guix-data-service"})
24838 The system group to run the service as.
24840 @item @code{port} (default: @code{8765})
24841 The port to bind the web service to.
24843 @item @code{host} (default: @code{"127.0.0.1"})
24844 The host to bind the web service to.
24846 @item @code{getmail-idle-mailboxes} (default: @code{#f})
24847 If set, this is the list of mailboxes that the getmail service will be
24848 configured to listen to.
24850 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
24851 If set, this is the @code{getmail-retriever-configuration} object with
24852 which to configure getmail to fetch mail from the guix-commits mailing
24859 @node Miscellaneous Services
24860 @subsection Miscellaneous Services
24862 @cindex fingerprint
24863 @subsubheading Fingerprint Service
24865 The @code{(gnu services authentication)} module provides a DBus service to
24866 read and identify fingerprints via a fingerprint sensor.
24868 @defvr {Scheme Variable} fprintd-service-type
24869 The service type for @command{fprintd}, which provides the fingerprint
24870 reading capability.
24873 (service fprintd-service-type)
24878 @subsubheading System Control Service
24880 The @code{(gnu services sysctl)} provides a service to configure kernel
24881 parameters at boot.
24883 @defvr {Scheme Variable} sysctl-service-type
24884 The service type for @command{sysctl}, which modifies kernel parameters
24885 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
24889 (service sysctl-service-type
24890 (sysctl-configuration
24891 (settings '(("net.ipv4.ip_forward" . "1")))))
24895 @deftp {Data Type} sysctl-configuration
24896 The data type representing the configuration of @command{sysctl}.
24899 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
24900 The @command{sysctl} executable to use.
24902 @item @code{settings} (default: @code{'()})
24903 An association list specifies kernel parameters and their values.
24908 @subsubheading PC/SC Smart Card Daemon Service
24910 The @code{(gnu services security-token)} module provides the following service
24911 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
24912 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
24913 manager that coordinates communications with smart card readers, smart cards
24914 and cryptographic tokens that are connected to the system.
24916 @defvr {Scheme Variable} pcscd-service-type
24917 Service type for the @command{pcscd} service. Its value must be a
24918 @code{pcscd-configuration} object. To run pcscd in the default
24919 configuration, instantiate it as:
24922 (service pcscd-service-type)
24926 @deftp {Data Type} pcscd-configuration
24927 The data type representing the configuration of @command{pcscd}.
24930 @item @code{pcsc-lite} (default: @code{pcsc-lite})
24931 The pcsc-lite package that provides pcscd.
24932 @item @code{usb-drivers} (default: @code{(list ccid)})
24933 List of packages that provide USB drivers to pcscd. Drivers are expected to be
24934 under @file{pcsc/drivers} in the store directory of the package.
24939 @subsubheading Lirc Service
24941 The @code{(gnu services lirc)} module provides the following service.
24943 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
24944 [#:device #f] [#:driver #f] [#:config-file #f] @
24945 [#:extra-options '()]
24946 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
24947 decodes infrared signals from remote controls.
24949 Optionally, @var{device}, @var{driver} and @var{config-file}
24950 (configuration file name) may be specified. See @command{lircd} manual
24953 Finally, @var{extra-options} is a list of additional command-line options
24954 passed to @command{lircd}.
24958 @subsubheading Spice Service
24960 The @code{(gnu services spice)} module provides the following service.
24962 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
24963 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
24964 that enables sharing the clipboard with a vm and setting the guest display
24965 resolution when the graphical console window resizes.
24968 @cindex inputattach
24969 @subsubheading inputattach Service
24971 @cindex tablet input, for Xorg
24972 @cindex touchscreen input, for Xorg
24973 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
24974 use input devices such as Wacom tablets, touchscreens, or joysticks with the
24975 Xorg display server.
24977 @deffn {Scheme Variable} inputattach-service-type
24978 Type of a service that runs @command{inputattach} on a device and
24979 dispatches events from it.
24982 @deftp {Data Type} inputattach-configuration
24984 @item @code{device-type} (default: @code{"wacom"})
24985 The type of device to connect to. Run @command{inputattach --help}, from the
24986 @code{inputattach} package, to see the list of supported device types.
24988 @item @code{device} (default: @code{"/dev/ttyS0"})
24989 The device file to connect to the device.
24991 @item @code{baud-rate} (default: @code{#f})
24992 Baud rate to use for the serial connection.
24993 Should be a number or @code{#f}.
24995 @item @code{log-file} (default: @code{#f})
24996 If true, this must be the name of a file to log messages to.
25000 @subsection Dictionary Services
25002 The @code{(gnu services dict)} module provides the following service:
25004 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25005 Return a service that runs the @command{dicod} daemon, an implementation
25006 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25008 The optional @var{config} argument specifies the configuration for
25009 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25010 default it serves the GNU Collaborative International Dictonary of English.
25012 You can add @command{open localhost} to your @file{~/.dico} file to make
25013 @code{localhost} the default server for @command{dico} client
25014 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25017 @deftp {Data Type} dicod-configuration
25018 Data type representing the configuration of dicod.
25021 @item @code{dico} (default: @var{dico})
25022 Package object of the GNU Dico dictionary server.
25024 @item @code{interfaces} (default: @var{'("localhost")})
25025 This is the list of IP addresses and ports and possibly socket file
25026 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25027 dico, GNU Dico Manual}).
25029 @item @code{handlers} (default: @var{'()})
25030 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25032 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25033 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25037 @deftp {Data Type} dicod-handler
25038 Data type representing a dictionary handler (module instance).
25042 Name of the handler (module instance).
25044 @item @code{module} (default: @var{#f})
25045 Name of the dicod module of the handler (instance). If it is @code{#f},
25046 the module has the same name as the handler.
25047 (@pxref{Modules,,, dico, GNU Dico Manual}).
25049 @item @code{options}
25050 List of strings or gexps representing the arguments for the module handler
25054 @deftp {Data Type} dicod-database
25055 Data type representing a dictionary database.
25059 Name of the database, will be used in DICT commands.
25061 @item @code{handler}
25062 Name of the dicod handler (module instance) used by this database
25063 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25065 @item @code{complex?} (default: @var{#f})
25066 Whether the database configuration complex. The complex configuration
25067 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25069 @item @code{options}
25070 List of strings or gexps representing the arguments for the database
25071 (@pxref{Databases,,, dico, GNU Dico Manual}).
25075 @defvr {Scheme Variable} %dicod-database:gcide
25076 A @code{<dicod-database>} object serving the GNU Collaborative International
25077 Dictionary of English using the @code{gcide} package.
25080 The following is an example @code{dicod-service} configuration.
25083 (dicod-service #:config
25084 (dicod-configuration
25085 (handlers (list (dicod-handler
25089 (list #~(string-append "dbdir=" #$wordnet))))))
25090 (databases (list (dicod-database
25093 (handler "wordnet")
25094 (options '("database=wn")))
25095 %dicod-database:gcide))))
25099 @subsubheading Docker Service
25101 The @code{(gnu services docker)} module provides the following services.
25103 @defvr {Scheme Variable} docker-service-type
25105 This is the type of the service that runs @url{https://www.docker.com,Docker},
25106 a daemon that can execute application bundles (sometimes referred to as
25107 ``containers'') in isolated environments.
25111 @deftp {Data Type} docker-configuration
25112 This is the data type representing the configuration of Docker and Containerd.
25116 @item @code{package} (default: @code{docker})
25117 The Docker package to use.
25119 @item @code{containerd} (default: @var{containerd})
25120 The Containerd package to use.
25126 @subsubheading Auditd Service
25128 The @code{(gnu services auditd)} module provides the following service.
25130 @defvr {Scheme Variable} auditd-service-type
25132 This is the type of the service that runs
25133 @url{https://people.redhat.com/sgrubb/audit/,auditd},
25134 a daemon that tracks security-relevant information on your system.
25136 Examples of things that can be tracked:
25146 Failed login attempts
25153 @command{auditctl} from the @code{audit} package can be used in order
25154 to add or remove events to be tracked (until the next reboot).
25155 In order to permanently track events, put the command line arguments
25156 of auditctl into @file{/etc/audit/audit.rules}.
25157 @command{aureport} from the @code{audit} package can be used in order
25158 to view a report of all recorded events.
25159 The audit daemon usually logs into the directory @file{/var/log/audit}.
25163 @deftp {Data Type} auditd-configuration
25164 This is the data type representing the configuration of auditd.
25168 @item @code{audit} (default: @code{audit})
25169 The audit package to use.
25174 @defvr {Scheme Variable} singularity-service-type
25175 This is the type of the service that allows you to run
25176 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
25177 create and run application bundles (aka. ``containers''). The value for this
25178 service is the Singularity package to use.
25180 The service does not install a daemon; instead, it installs helper programs as
25181 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
25182 @command{singularity run} and similar commands.
25186 @subsubheading Nix service
25188 The @code{(gnu services nix)} module provides the following service.
25190 @defvr {Scheme Variable} nix-service-type
25192 This is the type of the service that runs build daemon of the
25193 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
25197 (use-modules (gnu))
25198 (use-service-modules nix)
25199 (use-package-modules package-management)
25203 (packages (append (list nix)
25206 (services (append (list (service nix-service-type))
25210 After @command{guix system reconfigure} configure Nix for your user:
25213 @item Add a Nix channel and update it. See
25214 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
25216 @item Create a symlink to your profile and activate Nix profile:
25220 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
25221 $ source /run/current-system/profile/etc/profile.d/nix.sh
25226 @node Setuid Programs
25227 @section Setuid Programs
25229 @cindex setuid programs
25230 Some programs need to run with ``root'' privileges, even when they are
25231 launched by unprivileged users. A notorious example is the
25232 @command{passwd} program, which users can run to change their
25233 password, and which needs to access the @file{/etc/passwd} and
25234 @file{/etc/shadow} files---something normally restricted to root, for
25235 obvious security reasons. To address that, these executables are
25236 @dfn{setuid-root}, meaning that they always run with root privileges
25237 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
25238 for more info about the setuid mechanism.)
25240 The store itself @emph{cannot} contain setuid programs: that would be a
25241 security issue since any user on the system can write derivations that
25242 populate the store (@pxref{The Store}). Thus, a different mechanism is
25243 used: instead of changing the setuid bit directly on files that are in
25244 the store, we let the system administrator @emph{declare} which programs
25245 should be setuid root.
25247 The @code{setuid-programs} field of an @code{operating-system}
25248 declaration contains a list of G-expressions denoting the names of
25249 programs to be setuid-root (@pxref{Using the Configuration System}).
25250 For instance, the @command{passwd} program, which is part of the Shadow
25251 package, can be designated by this G-expression (@pxref{G-Expressions}):
25254 #~(string-append #$shadow "/bin/passwd")
25257 A default set of setuid programs is defined by the
25258 @code{%setuid-programs} variable of the @code{(gnu system)} module.
25260 @defvr {Scheme Variable} %setuid-programs
25261 A list of G-expressions denoting common programs that are setuid-root.
25263 The list includes commands such as @command{passwd}, @command{ping},
25264 @command{su}, and @command{sudo}.
25267 Under the hood, the actual setuid programs are created in the
25268 @file{/run/setuid-programs} directory at system activation time. The
25269 files in this directory refer to the ``real'' binaries, which are in the
25272 @node X.509 Certificates
25273 @section X.509 Certificates
25275 @cindex HTTPS, certificates
25276 @cindex X.509 certificates
25278 Web servers available over HTTPS (that is, HTTP over the transport-layer
25279 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
25280 that the client can then use to @emph{authenticate} the server. To do
25281 that, clients verify that the server's certificate is signed by a
25282 so-called @dfn{certificate authority} (CA). But to verify the CA's
25283 signature, clients must have first acquired the CA's certificate.
25285 Web browsers such as GNU@tie{}IceCat include their own set of CA
25286 certificates, such that they are able to verify CA signatures
25289 However, most other programs that can talk HTTPS---@command{wget},
25290 @command{git}, @command{w3m}, etc.---need to be told where CA
25291 certificates can be found.
25293 @cindex @code{nss-certs}
25294 In Guix, this is done by adding a package that provides certificates
25295 to the @code{packages} field of the @code{operating-system} declaration
25296 (@pxref{operating-system Reference}). Guix includes one such package,
25297 @code{nss-certs}, which is a set of CA certificates provided as part of
25298 Mozilla's Network Security Services.
25300 Note that it is @emph{not} part of @code{%base-packages}, so you need to
25301 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
25302 most applications and libraries look for certificates by default, points
25303 to the certificates installed globally.
25305 Unprivileged users, including users of Guix on a foreign distro,
25306 can also install their own certificate package in
25307 their profile. A number of environment variables need to be defined so
25308 that applications and libraries know where to find them. Namely, the
25309 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
25310 variables. Some applications add their own environment variables; for
25311 instance, the Git version control system honors the certificate bundle
25312 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
25313 would typically run something like:
25316 $ guix install nss-certs
25317 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
25318 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25319 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
25322 As another example, R requires the @code{CURL_CA_BUNDLE} environment
25323 variable to point to a certificate bundle, so you would have to run
25324 something like this:
25327 $ guix install nss-certs
25328 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25331 For other applications you may want to look up the required environment
25332 variable in the relevant documentation.
25335 @node Name Service Switch
25336 @section Name Service Switch
25338 @cindex name service switch
25340 The @code{(gnu system nss)} module provides bindings to the
25341 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
25342 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
25343 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
25344 extended with new ``name'' lookup methods for system databases, which
25345 includes host names, service names, user accounts, and more (@pxref{Name
25346 Service Switch, System Databases and Name Service Switch,, libc, The GNU
25347 C Library Reference Manual}).
25349 The NSS configuration specifies, for each system database, which lookup
25350 method is to be used, and how the various methods are chained
25351 together---for instance, under which circumstances NSS should try the
25352 next method in the list. The NSS configuration is given in the
25353 @code{name-service-switch} field of @code{operating-system} declarations
25354 (@pxref{operating-system Reference, @code{name-service-switch}}).
25357 @cindex .local, host name lookup
25358 As an example, the declaration below configures the NSS to use the
25359 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
25360 back-end}, which supports host name lookups over multicast DNS (mDNS)
25361 for host names ending in @code{.local}:
25364 (name-service-switch
25365 (hosts (list %files ;first, check /etc/hosts
25367 ;; If the above did not succeed, try
25368 ;; with 'mdns_minimal'.
25370 (name "mdns_minimal")
25372 ;; 'mdns_minimal' is authoritative for
25373 ;; '.local'. When it returns "not found",
25374 ;; no need to try the next methods.
25375 (reaction (lookup-specification
25376 (not-found => return))))
25378 ;; Then fall back to DNS.
25382 ;; Finally, try with the "full" 'mdns'.
25387 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
25388 contains this configuration, so you will not have to type it if all you
25389 want is to have @code{.local} host lookup working.
25391 Note that, in this case, in addition to setting the
25392 @code{name-service-switch} of the @code{operating-system} declaration,
25393 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
25394 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
25395 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
25396 to the name service cache daemon (@pxref{Base Services,
25397 @code{nscd-service}}).
25399 For convenience, the following variables provide typical NSS
25402 @defvr {Scheme Variable} %default-nss
25403 This is the default name service switch configuration, a
25404 @code{name-service-switch} object.
25407 @defvr {Scheme Variable} %mdns-host-lookup-nss
25408 This is the name service switch configuration with support for host name
25409 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
25412 The reference for name service switch configuration is given below. It
25413 is a direct mapping of the configuration file format of the C library , so
25414 please refer to the C library manual for more information (@pxref{NSS
25415 Configuration File,,, libc, The GNU C Library Reference Manual}).
25416 Compared to the configuration file format of libc NSS, it has the advantage
25417 not only of adding this warm parenthetic feel that we like, but also
25418 static checks: you will know about syntax errors and typos as soon as you
25419 run @command{guix system}.
25421 @deftp {Data Type} name-service-switch
25423 This is the data type representation the configuration of libc's name
25424 service switch (NSS). Each field below represents one of the supported
25441 The system databases handled by the NSS. Each of these fields must be a
25442 list of @code{<name-service>} objects (see below).
25446 @deftp {Data Type} name-service
25448 This is the data type representing an actual name service and the
25449 associated lookup action.
25453 A string denoting the name service (@pxref{Services in the NSS
25454 configuration,,, libc, The GNU C Library Reference Manual}).
25456 Note that name services listed here must be visible to nscd. This is
25457 achieved by passing the @code{#:name-services} argument to
25458 @code{nscd-service} the list of packages providing the needed name
25459 services (@pxref{Base Services, @code{nscd-service}}).
25462 An action specified using the @code{lookup-specification} macro
25463 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
25464 Reference Manual}). For example:
25467 (lookup-specification (unavailable => continue)
25468 (success => return))
25473 @node Initial RAM Disk
25474 @section Initial RAM Disk
25477 @cindex initial RAM disk
25478 For bootstrapping purposes, the Linux-Libre kernel is passed an
25479 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
25480 root file system as well as an initialization script. The latter is
25481 responsible for mounting the real root file system, and for loading any
25482 kernel modules that may be needed to achieve that.
25484 The @code{initrd-modules} field of an @code{operating-system}
25485 declaration allows you to specify Linux-libre kernel modules that must
25486 be available in the initrd. In particular, this is where you would list
25487 modules needed to actually drive the hard disk where your root partition
25488 is---although the default value of @code{initrd-modules} should cover
25489 most use cases. For example, assuming you need the @code{megaraid_sas}
25490 module in addition to the default modules to be able to access your root
25491 file system, you would write:
25496 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
25499 @defvr {Scheme Variable} %base-initrd-modules
25500 This is the list of kernel modules included in the initrd by default.
25503 Furthermore, if you need lower-level customization, the @code{initrd}
25504 field of an @code{operating-system} declaration allows
25505 you to specify which initrd you would like to use. The @code{(gnu
25506 system linux-initrd)} module provides three ways to build an initrd: the
25507 high-level @code{base-initrd} procedure and the low-level
25508 @code{raw-initrd} and @code{expression->initrd} procedures.
25510 The @code{base-initrd} procedure is intended to cover most common uses.
25511 For example, if you want to add a bunch of kernel modules to be loaded
25512 at boot time, you can define the @code{initrd} field of the operating
25513 system declaration like this:
25516 (initrd (lambda (file-systems . rest)
25517 ;; Create a standard initrd but set up networking
25518 ;; with the parameters QEMU expects by default.
25519 (apply base-initrd file-systems
25520 #:qemu-networking? #t
25524 The @code{base-initrd} procedure also handles common use cases that
25525 involves using the system as a QEMU guest, or as a ``live'' system with
25526 volatile root file system.
25528 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
25529 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
25530 such as trying to guess which kernel modules and packages should be included
25531 to the initrd. An example use of @code{raw-initrd} is when a user has
25532 a custom Linux kernel configuration and default kernel modules included by
25533 @code{base-initrd} are not available.
25535 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
25536 honors several options passed on the Linux kernel command line
25537 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
25538 @code{-append} option of QEMU), notably:
25541 @item --load=@var{boot}
25542 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
25543 program, once it has mounted the root file system.
25545 Guix uses this option to yield control to a boot program that runs the
25546 service activation programs and then spawns the GNU@tie{}Shepherd, the
25547 initialization system.
25549 @item --root=@var{root}
25550 Mount @var{root} as the root file system. @var{root} can be a
25551 device name like @code{/dev/sda1}, a file system label, or a file system
25554 @item --system=@var{system}
25555 Have @file{/run/booted-system} and @file{/run/current-system} point to
25558 @item modprobe.blacklist=@var{modules}@dots{}
25559 @cindex module, black-listing
25560 @cindex black list, of kernel modules
25561 Instruct the initial RAM disk as well as the @command{modprobe} command
25562 (from the kmod package) to refuse to load @var{modules}. @var{modules}
25563 must be a comma-separated list of module names---e.g.,
25564 @code{usbkbd,9pnet}.
25567 Start a read-eval-print loop (REPL) from the initial RAM disk before it
25568 tries to load kernel modules and to mount the root file system. Our
25569 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
25570 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
25571 Manual}, for more information on Guile's REPL.
25575 Now that you know all the features that initial RAM disks produced by
25576 @code{base-initrd} and @code{raw-initrd} provide,
25577 here is how to use it and customize it further.
25580 @cindex initial RAM disk
25581 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
25582 [#:linux-modules '()] [#:mapped-devices '()] @
25583 [#:keyboard-layout #f] @
25584 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
25585 Return a derivation that builds a raw initrd. @var{file-systems} is
25586 a list of file systems to be mounted by the initrd, possibly in addition to
25587 the root file system specified on the kernel command line via @code{--root}.
25588 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
25589 @var{mapped-devices} is a list of device mappings to realize before
25590 @var{file-systems} are mounted (@pxref{Mapped Devices}).
25591 @var{helper-packages} is a list of packages to be copied in the initrd. It may
25592 include @code{e2fsck/static} or other packages needed by the initrd to check
25593 the root file system.
25595 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25596 the desired console keyboard layout. This is done before @var{mapped-devices}
25597 are set up and before @var{file-systems} are mounted such that, should the
25598 user need to enter a passphrase or use the REPL, this happens using the
25599 intended keyboard layout.
25601 When @var{qemu-networking?} is true, set up networking with the standard QEMU
25602 parameters. When @var{virtio?} is true, load additional modules so that the
25603 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
25605 When @var{volatile-root?} is true, the root file system is writable but any changes
25609 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
25610 [#:mapped-devices '()] [#:keyboard-layout #f] @
25611 [#:qemu-networking? #f] [#:volatile-root? #f] @
25612 [#:linux-modules '()]
25613 Return as a file-like object a generic initrd, with kernel
25614 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
25615 mounted by the initrd, possibly in addition to the root file system specified
25616 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
25617 mappings to realize before @var{file-systems} are mounted.
25619 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25620 the desired console keyboard layout. This is done before @var{mapped-devices}
25621 are set up and before @var{file-systems} are mounted such that, should the
25622 user need to enter a passphrase or use the REPL, this happens using the
25623 intended keyboard layout.
25625 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
25627 The initrd is automatically populated with all the kernel modules necessary
25628 for @var{file-systems} and for the given options. Additional kernel
25629 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
25630 loaded at boot time in the order in which they appear.
25633 Needless to say, the initrds we produce and use embed a
25634 statically-linked Guile, and the initialization program is a Guile
25635 program. That gives a lot of flexibility. The
25636 @code{expression->initrd} procedure builds such an initrd, given the
25637 program to run in that initrd.
25639 @deffn {Scheme Procedure} expression->initrd @var{exp} @
25640 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
25641 Return as a file-like object a Linux initrd (a gzipped cpio archive)
25642 containing @var{guile} and that evaluates @var{exp}, a G-expression,
25643 upon booting. All the derivations referenced by @var{exp} are
25644 automatically copied to the initrd.
25647 @node Bootloader Configuration
25648 @section Bootloader Configuration
25651 @cindex boot loader
25653 The operating system supports multiple bootloaders. The bootloader is
25654 configured using @code{bootloader-configuration} declaration. All the
25655 fields of this structure are bootloader agnostic except for one field,
25656 @code{bootloader} that indicates the bootloader to be configured and
25659 Some of the bootloaders do not honor every field of
25660 @code{bootloader-configuration}. For instance, the extlinux
25661 bootloader does not support themes and thus ignores the @code{theme}
25664 @deftp {Data Type} bootloader-configuration
25665 The type of a bootloader configuration declaration.
25669 @item @code{bootloader}
25670 @cindex EFI, bootloader
25671 @cindex UEFI, bootloader
25672 @cindex BIOS, bootloader
25673 The bootloader to use, as a @code{bootloader} object. For now
25674 @code{grub-bootloader}, @code{grub-efi-bootloader},
25675 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
25677 @vindex grub-efi-bootloader
25678 @code{grub-efi-bootloader} allows to boot on modern systems using the
25679 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
25680 use if the installation image contains a @file{/sys/firmware/efi} directory
25681 when you boot it on your system.
25683 @vindex grub-bootloader
25684 @code{grub-bootloader} allows you to boot in particular Intel-based machines
25685 in ``legacy'' BIOS mode.
25687 @cindex ARM, bootloaders
25688 @cindex AArch64, bootloaders
25689 Available bootloaders are described in @code{(gnu bootloader @dots{})}
25690 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
25691 of bootloaders for a wide range of ARM and AArch64 systems, using the
25692 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
25694 @item @code{target}
25695 This is a string denoting the target onto which to install the
25698 The interpretation depends on the bootloader in question. For
25699 @code{grub-bootloader}, for example, it should be a device name understood by
25700 the bootloader @command{installer} command, such as @code{/dev/sda} or
25701 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
25702 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
25703 system, usually @file{/boot/efi}.
25705 @item @code{menu-entries} (default: @code{()})
25706 A possibly empty list of @code{menu-entry} objects (see below), denoting
25707 entries to appear in the bootloader menu, in addition to the current
25708 system entry and the entry pointing to previous system generations.
25710 @item @code{default-entry} (default: @code{0})
25711 The index of the default boot menu entry. Index 0 is for the entry of the
25714 @item @code{timeout} (default: @code{5})
25715 The number of seconds to wait for keyboard input before booting. Set to
25716 0 to boot immediately, and to -1 to wait indefinitely.
25718 @cindex keyboard layout, for the bootloader
25719 @item @code{keyboard-layout} (default: @code{#f})
25720 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
25721 layout, usually US@tie{}English (``qwerty'').
25723 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
25727 This option is currently ignored by bootloaders other than @code{grub} and
25731 @item @code{theme} (default: @var{#f})
25732 The bootloader theme object describing the theme to use. If no theme
25733 is provided, some bootloaders might use a default theme, that's true
25736 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
25737 The output terminals used for the bootloader boot menu, as a list of
25738 symbols. GRUB accepts the values: @code{console}, @code{serial},
25739 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
25740 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
25741 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
25742 configuration,,, grub,GNU GRUB manual}).
25744 @item @code{terminal-inputs} (default: @code{'()})
25745 The input terminals used for the bootloader boot menu, as a list of
25746 symbols. For GRUB, the default is the native platform terminal as
25747 determined at run-time. GRUB accepts the values: @code{console},
25748 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
25749 @code{usb_keyboard}. This field corresponds to the GRUB variable
25750 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
25753 @item @code{serial-unit} (default: @code{#f})
25754 The serial unit used by the bootloader, as an integer from 0 to 3.
25755 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
25756 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25758 @item @code{serial-speed} (default: @code{#f})
25759 The speed of the serial interface, as an integer. For GRUB, the
25760 default value is chosen at run-time; currently GRUB chooses
25761 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25768 Should you want to list additional boot menu entries @i{via} the
25769 @code{menu-entries} field above, you will need to create them with the
25770 @code{menu-entry} form. For example, imagine you want to be able to
25771 boot another distro (hard to imagine!), you can define a menu entry
25776 (label "The Other Distro")
25777 (linux "/boot/old/vmlinux-2.6.32")
25778 (linux-arguments '("root=/dev/sda2"))
25779 (initrd "/boot/old/initrd"))
25784 @deftp {Data Type} menu-entry
25785 The type of an entry in the bootloader menu.
25790 The label to show in the menu---e.g., @code{"GNU"}.
25793 The Linux kernel image to boot, for example:
25796 (file-append linux-libre "/bzImage")
25799 For GRUB, it is also possible to specify a device explicitly in the
25800 file path using GRUB's device naming convention (@pxref{Naming
25801 convention,,, grub, GNU GRUB manual}), for example:
25804 "(hd0,msdos1)/boot/vmlinuz"
25807 If the device is specified explicitly as above, then the @code{device}
25808 field is ignored entirely.
25810 @item @code{linux-arguments} (default: @code{()})
25811 The list of extra Linux kernel command-line arguments---e.g.,
25812 @code{("console=ttyS0")}.
25814 @item @code{initrd}
25815 A G-Expression or string denoting the file name of the initial RAM disk
25816 to use (@pxref{G-Expressions}).
25817 @item @code{device} (default: @code{#f})
25818 The device where the kernel and initrd are to be found---i.e., for GRUB,
25819 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
25821 This may be a file system label (a string), a file system UUID (a
25822 bytevector, @pxref{File Systems}), or @code{#f}, in which case
25823 the bootloader will search the device containing the file specified by
25824 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
25825 must @emph{not} be an OS device name such as @file{/dev/sda1}.
25830 @c FIXME: Write documentation once it's stable.
25831 For now only GRUB has theme support. GRUB themes are created using
25832 the @code{grub-theme} form, which is not documented yet.
25834 @defvr {Scheme Variable} %default-theme
25835 This is the default GRUB theme used by the operating system if no
25836 @code{theme} field is specified in @code{bootloader-configuration}
25839 It comes with a fancy background image displaying the GNU and Guix
25844 @node Invoking guix system
25845 @section Invoking @code{guix system}
25847 Once you have written an operating system declaration as seen in the
25848 previous section, it can be @dfn{instantiated} using the @command{guix
25849 system} command. The synopsis is:
25852 guix system @var{options}@dots{} @var{action} @var{file}
25855 @var{file} must be the name of a file containing an
25856 @code{operating-system} declaration. @var{action} specifies how the
25857 operating system is instantiated. Currently the following values are
25862 Display available service type definitions that match the given regular
25863 expressions, sorted by relevance:
25866 $ guix system search console font
25867 name: console-fonts
25868 location: gnu/services/base.scm:729:2
25869 extends: shepherd-root
25870 description: Install the given fonts on the specified ttys (fonts are
25871 + per virtual console on GNU/Linux). The value of this service is a list
25872 + of tty/font pairs like:
25874 + '(("tty1" . "LatGrkCyr-8x16"))
25878 location: gnu/services/base.scm:1048:2
25879 extends: shepherd-root
25880 description: Provide console login using the `mingetty' program.
25884 location: gnu/services/base.scm:775:2
25886 description: Provide a console log-in service as specified by its
25887 + configuration value, a `login-configuration' object.
25893 As for @command{guix package --search}, the result is written in
25894 @code{recutils} format, which makes it easy to filter the output
25895 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
25898 Build the operating system described in @var{file}, activate it, and
25899 switch to it@footnote{This action (and the related actions
25900 @code{switch-generation} and @code{roll-back}) are usable only on
25901 systems already running Guix System.}.
25903 This effects all the configuration specified in @var{file}: user
25904 accounts, system services, global package list, setuid programs, etc.
25905 The command starts system services specified in @var{file} that are not
25906 currently running; if a service is currently running this command will
25907 arrange for it to be upgraded the next time it is stopped (e.g.@: by
25908 @code{herd stop X} or @code{herd restart X}).
25910 This command creates a new generation whose number is one greater than
25911 the current generation (as reported by @command{guix system
25912 list-generations}). If that generation already exists, it will be
25913 overwritten. This behavior mirrors that of @command{guix package}
25914 (@pxref{Invoking guix package}).
25916 It also adds a bootloader menu entry for the new OS configuration,
25917 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
25918 entries for older configurations to a submenu, allowing you to choose
25919 an older system generation at boot time should you need it.
25922 @c The paragraph below refers to the problem discussed at
25923 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
25924 It is highly recommended to run @command{guix pull} once before you run
25925 @command{guix system reconfigure} for the first time (@pxref{Invoking
25926 guix pull}). Failing to do that you would see an older version of Guix
25927 once @command{reconfigure} has completed.
25930 @item switch-generation
25931 @cindex generations
25932 Switch to an existing system generation. This action atomically
25933 switches the system profile to the specified system generation. It
25934 also rearranges the system's existing bootloader menu entries. It
25935 makes the menu entry for the specified system generation the default,
25936 and it moves the entries for the other generatiors to a submenu, if
25937 supported by the bootloader being used. The next time the system
25938 boots, it will use the specified system generation.
25940 The bootloader itself is not being reinstalled when using this
25941 command. Thus, the installed bootloader is used with an updated
25942 configuration file.
25944 The target generation can be specified explicitly by its generation
25945 number. For example, the following invocation would switch to system
25949 guix system switch-generation 7
25952 The target generation can also be specified relative to the current
25953 generation with the form @code{+N} or @code{-N}, where @code{+3} means
25954 ``3 generations ahead of the current generation,'' and @code{-1} means
25955 ``1 generation prior to the current generation.'' When specifying a
25956 negative value such as @code{-1}, you must precede it with @code{--} to
25957 prevent it from being parsed as an option. For example:
25960 guix system switch-generation -- -1
25963 Currently, the effect of invoking this action is @emph{only} to switch
25964 the system profile to an existing generation and rearrange the
25965 bootloader menu entries. To actually start using the target system
25966 generation, you must reboot after running this action. In the future,
25967 it will be updated to do the same things as @command{reconfigure},
25968 like activating and deactivating services.
25970 This action will fail if the specified generation does not exist.
25973 @cindex rolling back
25974 Switch to the preceding system generation. The next time the system
25975 boots, it will use the preceding system generation. This is the inverse
25976 of @command{reconfigure}, and it is exactly the same as invoking
25977 @command{switch-generation} with an argument of @code{-1}.
25979 Currently, as with @command{switch-generation}, you must reboot after
25980 running this action to actually start using the preceding system
25983 @item delete-generations
25984 @cindex deleting system generations
25985 @cindex saving space
25986 Delete system generations, making them candidates for garbage collection
25987 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
25990 This works in the same way as @command{guix package --delete-generations}
25991 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
25992 arguments, all system generations but the current one are deleted:
25995 guix system delete-generations
25998 You can also select the generations you want to delete. The example below
25999 deletes all the system generations that are more than two month old:
26002 guix system delete-generations 2m
26005 Running this command automatically reinstalls the bootloader with an updated
26006 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
26007 longer lists the generations that have been deleted.
26010 Build the derivation of the operating system, which includes all the
26011 configuration files and programs needed to boot and run the system.
26012 This action does not actually install anything.
26015 Populate the given directory with all the files necessary to run the
26016 operating system specified in @var{file}. This is useful for first-time
26017 installations of Guix System. For instance:
26020 guix system init my-os-config.scm /mnt
26023 copies to @file{/mnt} all the store items required by the configuration
26024 specified in @file{my-os-config.scm}. This includes configuration
26025 files, packages, and so on. It also creates other essential files
26026 needed for the system to operate correctly---e.g., the @file{/etc},
26027 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
26029 This command also installs bootloader on the target specified in
26030 @file{my-os-config}, unless the @option{--no-bootloader} option was
26034 @cindex virtual machine
26036 @anchor{guix system vm}
26037 Build a virtual machine that contains the operating system declared in
26038 @var{file}, and return a script to run that virtual machine (VM).
26041 The @code{vm} action and others below
26042 can use KVM support in the Linux-libre kernel. Specifically, if the
26043 machine has hardware virtualization support, the corresponding
26044 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
26045 must exist and be readable and writable by the user and by the
26046 build users of the daemon (@pxref{Build Environment Setup}).
26049 Arguments given to the script are passed to QEMU as in the example
26050 below, which enables networking and requests 1@tie{}GiB of RAM for the
26054 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
26057 The VM shares its store with the host system.
26059 Additional file systems can be shared between the host and the VM using
26060 the @code{--share} and @code{--expose} command-line options: the former
26061 specifies a directory to be shared with write access, while the latter
26062 provides read-only access to the shared directory.
26064 The example below creates a VM in which the user's home directory is
26065 accessible read-only, and where the @file{/exchange} directory is a
26066 read-write mapping of @file{$HOME/tmp} on the host:
26069 guix system vm my-config.scm \
26070 --expose=$HOME --share=$HOME/tmp=/exchange
26073 On GNU/Linux, the default is to boot directly to the kernel; this has
26074 the advantage of requiring only a very tiny root disk image since the
26075 store of the host can then be mounted.
26077 The @code{--full-boot} option forces a complete boot sequence, starting
26078 with the bootloader. This requires more disk space since a root image
26079 containing at least the kernel, initrd, and bootloader data files must
26080 be created. The @code{--image-size} option can be used to specify the
26083 @cindex System images, creation in various formats
26084 @cindex Creating system images in various formats
26087 @itemx docker-image
26088 Return a virtual machine, disk image, or Docker image of the operating
26089 system declared in @var{file} that stands alone. By default,
26090 @command{guix system} estimates the size of the image needed to store
26091 the system, but you can use the @option{--image-size} option to specify
26092 a value. Docker images are built to contain exactly what they need, so
26093 the @option{--image-size} option is ignored in the case of
26094 @code{docker-image}.
26096 You can specify the root file system type by using the
26097 @option{--file-system-type} option. It defaults to @code{ext4}.
26099 When using @code{vm-image}, the returned image is in qcow2 format, which
26100 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
26101 for more information on how to run the image in a virtual machine.
26103 When using @code{disk-image}, a raw disk image is produced; it can be
26104 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
26105 the device corresponding to a USB stick, one can copy the image to it
26106 using the following command:
26109 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
26112 When using @code{docker-image}, a Docker image is produced. Guix builds
26113 the image from scratch, not from a pre-existing Docker base image. As a
26114 result, it contains @emph{exactly} what you define in the operating
26115 system configuration file. You can then load the image and launch a
26116 Docker container using commands like the following:
26119 image_id="`docker load < guix-system-docker-image.tar.gz`"
26120 container_id="`docker create $image_id`"
26121 docker start $container_id
26124 This command starts a new Docker container from the specified image. It
26125 will boot the Guix system in the usual manner, which means it will
26126 start any services you have defined in the operating system
26127 configuration. You can get an interactive shell running in the container
26128 using @command{docker exec}:
26131 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
26134 Depending on what you run in the Docker container, it
26135 may be necessary to give the container additional permissions. For
26136 example, if you intend to build software using Guix inside of the Docker
26137 container, you may need to pass the @option{--privileged} option to
26138 @code{docker create}.
26141 Return a script to run the operating system declared in @var{file}
26142 within a container. Containers are a set of lightweight isolation
26143 mechanisms provided by the kernel Linux-libre. Containers are
26144 substantially less resource-demanding than full virtual machines since
26145 the kernel, shared objects, and other resources can be shared with the
26146 host system; this also means they provide thinner isolation.
26148 Currently, the script must be run as root in order to support more than
26149 a single user and group. The container shares its store with the host
26152 As with the @code{vm} action (@pxref{guix system vm}), additional file
26153 systems to be shared between the host and container can be specified
26154 using the @option{--share} and @option{--expose} options:
26157 guix system container my-config.scm \
26158 --expose=$HOME --share=$HOME/tmp=/exchange
26162 This option requires Linux-libre 3.19 or newer.
26167 @var{options} can contain any of the common build options (@pxref{Common
26168 Build Options}). In addition, @var{options} can contain one of the
26172 @item --expression=@var{expr}
26173 @itemx -e @var{expr}
26174 Consider the operating-system @var{expr} evaluates to.
26175 This is an alternative to specifying a file which evaluates to an
26177 This is used to generate the Guix system installer @pxref{Building the
26178 Installation Image}).
26180 @item --system=@var{system}
26181 @itemx -s @var{system}
26182 Attempt to build for @var{system} instead of the host system type.
26183 This works as per @command{guix build} (@pxref{Invoking guix build}).
26187 Return the derivation file name of the given operating system without
26190 @item --file-system-type=@var{type}
26191 @itemx -t @var{type}
26192 For the @code{disk-image} action, create a file system of the given
26193 @var{type} on the image.
26195 When this option is omitted, @command{guix system} uses @code{ext4}.
26197 @cindex ISO-9660 format
26198 @cindex CD image format
26199 @cindex DVD image format
26200 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
26201 for burning on CDs and DVDs.
26203 @item --image-size=@var{size}
26204 For the @code{vm-image} and @code{disk-image} actions, create an image
26205 of the given @var{size}. @var{size} may be a number of bytes, or it may
26206 include a unit as a suffix (@pxref{Block size, size specifications,,
26207 coreutils, GNU Coreutils}).
26209 When this option is omitted, @command{guix system} computes an estimate
26210 of the image size as a function of the size of the system declared in
26215 For the @code{container} action, allow containers to access the host network,
26216 that is, do not create a network namespace.
26218 @item --root=@var{file}
26219 @itemx -r @var{file}
26220 Make @var{file} a symlink to the result, and register it as a garbage
26223 @item --skip-checks
26224 Skip pre-installation safety checks.
26226 By default, @command{guix system init} and @command{guix system
26227 reconfigure} perform safety checks: they make sure the file systems that
26228 appear in the @code{operating-system} declaration actually exist
26229 (@pxref{File Systems}), and that any Linux kernel modules that may be
26230 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
26231 RAM Disk}). Passing this option skips these tests altogether.
26234 @cindex on-error strategy
26235 @cindex error strategy
26236 @item --on-error=@var{strategy}
26237 Apply @var{strategy} when an error occurs when reading @var{file}.
26238 @var{strategy} may be one of the following:
26241 @item nothing-special
26242 Report the error concisely and exit. This is the default strategy.
26245 Likewise, but also display a backtrace.
26248 Report the error and enter Guile's debugger. From there, you can run
26249 commands such as @code{,bt} to get a backtrace, @code{,locals} to
26250 display local variable values, and more generally inspect the state of the
26251 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
26252 a list of available debugging commands.
26256 Once you have built, configured, re-configured, and re-re-configured
26257 your Guix installation, you may find it useful to list the operating
26258 system generations available on disk---and that you can choose from the
26259 bootloader boot menu:
26263 @item list-generations
26264 List a summary of each generation of the operating system available on
26265 disk, in a human-readable way. This is similar to the
26266 @option{--list-generations} option of @command{guix package}
26267 (@pxref{Invoking guix package}).
26269 Optionally, one can specify a pattern, with the same syntax that is used
26270 in @command{guix package --list-generations}, to restrict the list of
26271 generations displayed. For instance, the following command displays
26272 generations that are up to 10 days old:
26275 $ guix system list-generations 10d
26280 The @command{guix system} command has even more to offer! The following
26281 sub-commands allow you to visualize how your system services relate to
26284 @anchor{system-extension-graph}
26287 @item extension-graph
26288 Emit in Dot/Graphviz format to standard output the @dfn{service
26289 extension graph} of the operating system defined in @var{file}
26290 (@pxref{Service Composition}, for more information on service
26296 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
26299 produces a PDF file showing the extension relations among services.
26301 @anchor{system-shepherd-graph}
26302 @item shepherd-graph
26303 Emit in Dot/Graphviz format to standard output the @dfn{dependency
26304 graph} of shepherd services of the operating system defined in
26305 @var{file}. @xref{Shepherd Services}, for more information and for an
26310 @node Invoking guix deploy
26311 @section Invoking @code{guix deploy}
26313 We've already seen @code{operating-system} declarations used to manage a
26314 machine's configuration locally. Suppose you need to configure multiple
26315 machines, though---perhaps you're managing a service on the web that's
26316 comprised of several servers. @command{guix deploy} enables you to use those
26317 same @code{operating-system} declarations to manage multiple remote hosts at
26318 once as a logical ``deployment''.
26321 The functionality described in this section is still under development
26322 and is subject to change. Get in touch with us on
26323 @email{guix-devel@@gnu.org}!
26327 guix deploy @var{file}
26330 Such an invocation will deploy the machines that the code within @var{file}
26331 evaluates to. As an example, @var{file} might contain a definition like this:
26334 ;; This is a Guix deployment of a "bare bones" setup, with
26335 ;; no X11 display server, to a machine with an SSH daemon
26336 ;; listening on localhost:2222. A configuration such as this
26337 ;; may be appropriate for virtual machine with ports
26338 ;; forwarded to the host's loopback interface.
26340 (use-service-modules networking ssh)
26341 (use-package-modules bootloaders)
26345 (host-name "gnu-deployed")
26346 (timezone "Etc/UTC")
26347 (bootloader (bootloader-configuration
26348 (bootloader grub-bootloader)
26349 (target "/dev/vda")
26350 (terminal-outputs '(console))))
26351 (file-systems (cons (file-system
26353 (device "/dev/vda1")
26355 %base-file-systems))
26357 (append (list (service dhcp-client-service-type)
26358 (service openssh-service-type
26359 (openssh-configuration
26360 (permit-root-login #t)
26361 (allow-empty-passwords? #t))))
26365 (operating-system %system)
26366 (environment managed-host-environment-type)
26367 (configuration (machine-ssh-configuration
26368 (host-name "localhost")
26369 (system "x86_64-linux")
26371 (identity "./id_rsa")
26375 The file should evaluate to a list of @var{machine} objects. This example,
26376 upon being deployed, will create a new generation on the remote system
26377 realizing the @code{operating-system} declaration @var{%system}.
26378 @var{environment} and @var{configuration} specify how the machine should be
26379 provisioned---that is, how the computing resources should be created and
26380 managed. The above example does not create any resources, as a
26381 @code{'managed-host} is a machine that is already running the Guix system and
26382 available over the network. This is a particularly simple case; a more
26383 complex deployment may involve, for example, starting virtual machines through
26384 a Virtual Private Server (VPS) provider. In such a case, a different
26385 @var{environment} type would be used.
26387 Do note that you first need to generate a key pair on the coordinator machine
26388 to allow the daemon to export signed archives of files from the store
26389 (@pxref{Invoking guix archive}).
26392 # guix archive --generate-key
26396 Each target machine must authorize the key of the master machine so that it
26397 accepts store items it receives from the coordinator:
26400 # guix archive --authorize < coordinator-public-key.txt
26403 @code{user}, in this example, specifies the name of the user account to log in
26404 as to perform the deployment. Its default value is @code{root}, but root
26405 login over SSH may be forbidden in some cases. To work around this,
26406 @command{guix deploy} can log in as an unprivileged user and employ
26407 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
26408 currently installed on the remote and can be invoked non-interactively as
26409 @code{user}. That is: the line in @code{sudoers} granting @code{user} the
26410 ability to use @code{sudo} must contain the @code{NOPASSWD} tag.
26412 @deftp {Data Type} machine
26413 This is the data type representing a single machine in a heterogeneous Guix
26417 @item @code{operating-system}
26418 The object of the operating system configuration to deploy.
26420 @item @code{environment}
26421 An @code{environment-type} describing how the machine should be provisioned.
26423 @item @code{configuration} (default: @code{#f})
26424 An object describing the configuration for the machine's @code{environment}.
26425 If the @code{environment} has a default configuration, @code{#f} may be used.
26426 If @code{#f} is used for an environment with no default configuration,
26427 however, an error will be thrown.
26431 @deftp {Data Type} machine-ssh-configuration
26432 This is the data type representing the SSH client parameters for a machine
26433 with an @code{environment} of @code{managed-host-environment-type}.
26436 @item @code{host-name}
26437 @item @code{build-locally?} (default: @code{#t})
26438 If false, system derivations will be built on the machine being deployed to.
26439 @item @code{system}
26440 The system type describing the architecture of the machine being deployed
26441 to---e.g., @code{"x86_64-linux"}.
26442 @item @code{authorize?} (default: @code{#t})
26443 If true, the coordinator's signing key will be added to the remote's ACL
26445 @item @code{port} (default: @code{22})
26446 @item @code{user} (default: @code{"root"})
26447 @item @code{identity} (default: @code{#f})
26448 If specified, the path to the SSH private key to use to authenticate with the
26451 @item @code{host-key} (default: @code{#f})
26452 This should be the SSH host key of the machine, which looks like this:
26455 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
26458 When @code{host-key} is @code{#f}, the server is authenticated against
26459 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
26465 @deftp {Data Type} digital-ocean-configuration
26466 This is the data type describing the Droplet that should be created for a
26467 machine with an @code{environment} of @code{digital-ocean-environment-type}.
26470 @item @code{ssh-key}
26471 The path to the SSH private key to use to authenticate with the remote
26472 host. In the future, this field may not exist.
26474 A list of string ``tags'' that uniquely identify the machine. Must be given
26475 such that no two machines in the deployment have the same set of tags.
26476 @item @code{region}
26477 A Digital Ocean region slug, such as @code{"nyc3"}.
26479 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
26480 @item @code{enable-ipv6?}
26481 Whether or not the droplet should be created with IPv6 networking.
26485 @node Running Guix in a VM
26486 @section Running Guix in a Virtual Machine
26488 @cindex virtual machine
26489 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
26491 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
26492 This image is a compressed image in QCOW format. You will first need to
26493 decompress with @command{xz -d}, and then you can pass it to an emulator such
26494 as QEMU (see below for details).
26496 This image boots the Xfce graphical environment and it contains some
26497 commonly-used tools. You can install more software in the image by running
26498 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
26499 also reconfigure the system based on its initial configuration file available
26500 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
26502 Instead of using this pre-built image, one can also build their own virtual
26503 machine image using @command{guix system vm-image} (@pxref{Invoking guix
26504 system}). The returned image is in qcow2 format, which the
26505 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
26508 If you built your own image, you must copy it out of the store
26509 (@pxref{The Store}) and give yourself permission to write to the copy
26510 before you can use it. When invoking QEMU, you must choose a system
26511 emulator that is suitable for your hardware platform. Here is a minimal
26512 QEMU invocation that will boot the result of @command{guix system
26513 vm-image} on x86_64 hardware:
26516 $ qemu-system-x86_64 \
26517 -net user -net nic,model=virtio \
26518 -enable-kvm -m 1024 \
26519 -device virtio-blk,drive=myhd \
26520 -drive if=none,file=/tmp/qemu-image,id=myhd
26523 Here is what each of these options means:
26526 @item qemu-system-x86_64
26527 This specifies the hardware platform to emulate. This should match the
26531 Enable the unprivileged user-mode network stack. The guest OS can
26532 access the host but not vice versa. This is the simplest way to get the
26535 @item -net nic,model=virtio
26536 You must create a network interface of a given model. If you do not
26537 create a NIC, the boot will fail. Assuming your hardware platform is
26538 x86_64, you can get a list of available NIC models by running
26539 @command{qemu-system-x86_64 -net nic,model=help}.
26542 If your system has hardware virtualization extensions, enabling the
26543 virtual machine support (KVM) of the Linux kernel will make things run
26546 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
26548 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
26549 which may be insufficient for some operations.
26551 @item -device virtio-blk,drive=myhd
26552 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
26553 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
26554 better performance than if it were emulating a complete disk drive. See the
26555 QEMU and KVM documentation for more info.
26557 @item -drive if=none,file=/tmp/qemu-image,id=myhd
26558 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
26559 the ``myhd'' drive.
26562 The default @command{run-vm.sh} script that is returned by an invocation of
26563 @command{guix system vm} does not add a @command{-net user} flag by default.
26564 To get network access from within the vm add the @code{(dhcp-client-service)}
26565 to your system definition and start the VM using
26566 @command{`guix system vm config.scm` -net user}. An important caveat of using
26567 @command{-net user} for networking is that @command{ping} will not work, because
26568 it uses the ICMP protocol. You'll have to use a different command to check for
26569 network connectivity, for example @command{guix download}.
26571 @subsection Connecting Through SSH
26575 To enable SSH inside a VM you need to add an SSH server like
26576 @code{openssh-service-type} to your VM (@pxref{Networking Services,
26577 @code{openssh-service-type}}). In addition you need to forward the SSH port,
26578 22 by default, to the host. You can do this with
26581 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
26584 To connect to the VM you can run
26587 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
26590 The @command{-p} tells @command{ssh} the port you want to connect to.
26591 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
26592 every time you modify your @command{config.scm} file and the
26593 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
26594 connection to an unknown host every time you connect.
26596 @subsection Using @command{virt-viewer} with Spice
26598 As an alternative to the default @command{qemu} graphical client you can
26599 use the @command{remote-viewer} from the @command{virt-viewer} package. To
26600 connect pass the @command{-spice port=5930,disable-ticketing} flag to
26601 @command{qemu}. See previous section for further information on how to do this.
26603 Spice also allows you to do some nice stuff like share your clipboard with your
26604 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
26607 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
26608 -chardev spicevmc,name=vdagent,id=vdagent
26609 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
26610 name=com.redhat.spice.0
26613 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
26615 @node Defining Services
26616 @section Defining Services
26618 The previous sections show the available services and how one can combine
26619 them in an @code{operating-system} declaration. But how do we define
26620 them in the first place? And what is a service anyway?
26623 * Service Composition:: The model for composing services.
26624 * Service Types and Services:: Types and services.
26625 * Service Reference:: API reference.
26626 * Shepherd Services:: A particular type of service.
26629 @node Service Composition
26630 @subsection Service Composition
26634 Here we define a @dfn{service} as, broadly, something that extends the
26635 functionality of the operating system. Often a service is a process---a
26636 @dfn{daemon}---started when the system boots: a secure shell server, a
26637 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
26638 whose execution can be triggered by another daemon---e.g., an FTP server
26639 started by @command{inetd} or a D-Bus service activated by
26640 @command{dbus-daemon}. Occasionally, a service does not map to a
26641 daemon. For instance, the ``account'' service collects user accounts
26642 and makes sure they exist when the system runs; the ``udev'' service
26643 collects device management rules and makes them available to the eudev
26644 daemon; the @file{/etc} service populates the @file{/etc} directory
26647 @cindex service extensions
26648 Guix system services are connected by @dfn{extensions}. For instance, the
26649 secure shell service @emph{extends} the Shepherd---the
26650 initialization system, running as PID@tie{}1---by giving it the command
26651 lines to start and stop the secure shell daemon (@pxref{Networking
26652 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
26653 service by passing it its @file{.service} specification, and extends the
26654 udev service by passing it device management rules (@pxref{Desktop
26655 Services, @code{upower-service}}); the Guix daemon service extends the
26656 Shepherd by passing it the command lines to start and stop the daemon,
26657 and extends the account service by passing it a list of required build
26658 user accounts (@pxref{Base Services}).
26660 All in all, services and their ``extends'' relations form a directed
26661 acyclic graph (DAG). If we represent services as boxes and extensions
26662 as arrows, a typical system might provide something like this:
26664 @image{images/service-graph,,5in,Typical service extension graph.}
26666 @cindex system service
26667 At the bottom, we see the @dfn{system service}, which produces the
26668 directory containing everything to run and boot the system, as returned
26669 by the @command{guix system build} command. @xref{Service Reference},
26670 to learn about the other service types shown here.
26671 @xref{system-extension-graph, the @command{guix system extension-graph}
26672 command}, for information on how to generate this representation for a
26673 particular operating system definition.
26675 @cindex service types
26676 Technically, developers can define @dfn{service types} to express these
26677 relations. There can be any number of services of a given type on the
26678 system---for instance, a system running two instances of the GNU secure
26679 shell server (lsh) has two instances of @code{lsh-service-type}, with
26680 different parameters.
26682 The following section describes the programming interface for service
26683 types and services.
26685 @node Service Types and Services
26686 @subsection Service Types and Services
26688 A @dfn{service type} is a node in the DAG described above. Let us start
26689 with a simple example, the service type for the Guix build daemon
26690 (@pxref{Invoking guix-daemon}):
26693 (define guix-service-type
26697 (list (service-extension shepherd-root-service-type guix-shepherd-service)
26698 (service-extension account-service-type guix-accounts)
26699 (service-extension activation-service-type guix-activation)))
26700 (default-value (guix-configuration))))
26704 It defines three things:
26708 A name, whose sole purpose is to make inspection and debugging easier.
26711 A list of @dfn{service extensions}, where each extension designates the
26712 target service type and a procedure that, given the parameters of the
26713 service, returns a list of objects to extend the service of that type.
26715 Every service type has at least one service extension. The only
26716 exception is the @dfn{boot service type}, which is the ultimate service.
26719 Optionally, a default value for instances of this type.
26722 In this example, @code{guix-service-type} extends three services:
26725 @item shepherd-root-service-type
26726 The @code{guix-shepherd-service} procedure defines how the Shepherd
26727 service is extended. Namely, it returns a @code{<shepherd-service>}
26728 object that defines how @command{guix-daemon} is started and stopped
26729 (@pxref{Shepherd Services}).
26731 @item account-service-type
26732 This extension for this service is computed by @code{guix-accounts},
26733 which returns a list of @code{user-group} and @code{user-account}
26734 objects representing the build user accounts (@pxref{Invoking
26737 @item activation-service-type
26738 Here @code{guix-activation} is a procedure that returns a gexp, which is
26739 a code snippet to run at ``activation time''---e.g., when the service is
26743 A service of this type is instantiated like this:
26746 (service guix-service-type
26747 (guix-configuration
26749 (use-substitutes? #f)))
26752 The second argument to the @code{service} form is a value representing
26753 the parameters of this specific service instance.
26754 @xref{guix-configuration-type, @code{guix-configuration}}, for
26755 information about the @code{guix-configuration} data type. When the
26756 value is omitted, the default value specified by
26757 @code{guix-service-type} is used:
26760 (service guix-service-type)
26763 @code{guix-service-type} is quite simple because it extends other
26764 services but is not extensible itself.
26766 @c @subsubsubsection Extensible Service Types
26768 The service type for an @emph{extensible} service looks like this:
26771 (define udev-service-type
26772 (service-type (name 'udev)
26774 (list (service-extension shepherd-root-service-type
26775 udev-shepherd-service)))
26777 (compose concatenate) ;concatenate the list of rules
26778 (extend (lambda (config rules)
26780 (($ <udev-configuration> udev initial-rules)
26781 (udev-configuration
26782 (udev udev) ;the udev package to use
26783 (rules (append initial-rules rules)))))))))
26786 This is the service type for the
26787 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
26788 management daemon}. Compared to the previous example, in addition to an
26789 extension of @code{shepherd-root-service-type}, we see two new fields:
26793 This is the procedure to @dfn{compose} the list of extensions to
26794 services of this type.
26796 Services can extend the udev service by passing it lists of rules; we
26797 compose those extensions simply by concatenating them.
26800 This procedure defines how the value of the service is @dfn{extended} with
26801 the composition of the extensions.
26803 Udev extensions are composed into a list of rules, but the udev service
26804 value is itself a @code{<udev-configuration>} record. So here, we
26805 extend that record by appending the list of rules it contains to the
26806 list of contributed rules.
26809 This is a string giving an overview of the service type. The string can
26810 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
26811 @command{guix system search} command searches these strings and displays
26812 them (@pxref{Invoking guix system}).
26815 There can be only one instance of an extensible service type such as
26816 @code{udev-service-type}. If there were more, the
26817 @code{service-extension} specifications would be ambiguous.
26819 Still here? The next section provides a reference of the programming
26820 interface for services.
26822 @node Service Reference
26823 @subsection Service Reference
26825 We have seen an overview of service types (@pxref{Service Types and
26826 Services}). This section provides a reference on how to manipulate
26827 services and service types. This interface is provided by the
26828 @code{(gnu services)} module.
26830 @deffn {Scheme Procedure} service @var{type} [@var{value}]
26831 Return a new service of @var{type}, a @code{<service-type>} object (see
26832 below.) @var{value} can be any object; it represents the parameters of
26833 this particular service instance.
26835 When @var{value} is omitted, the default value specified by @var{type}
26836 is used; if @var{type} does not specify a default value, an error is
26839 For instance, this:
26842 (service openssh-service-type)
26846 is equivalent to this:
26849 (service openssh-service-type
26850 (openssh-configuration))
26853 In both cases the result is an instance of @code{openssh-service-type}
26854 with the default configuration.
26857 @deffn {Scheme Procedure} service? @var{obj}
26858 Return true if @var{obj} is a service.
26861 @deffn {Scheme Procedure} service-kind @var{service}
26862 Return the type of @var{service}---i.e., a @code{<service-type>} object.
26865 @deffn {Scheme Procedure} service-value @var{service}
26866 Return the value associated with @var{service}. It represents its
26870 Here is an example of how a service is created and manipulated:
26874 (service nginx-service-type
26875 (nginx-configuration
26877 (log-directory log-directory)
26878 (run-directory run-directory)
26879 (file config-file))))
26884 (eq? (service-kind s) nginx-service-type)
26888 The @code{modify-services} form provides a handy way to change the
26889 parameters of some of the services of a list such as
26890 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
26891 evaluates to a list of services. Of course, you could always use
26892 standard list combinators such as @code{map} and @code{fold} to do that
26893 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
26894 @code{modify-services} simply provides a more concise form for this
26897 @deffn {Scheme Syntax} modify-services @var{services} @
26898 (@var{type} @var{variable} => @var{body}) @dots{}
26900 Modify the services listed in @var{services} according to the given
26901 clauses. Each clause has the form:
26904 (@var{type} @var{variable} => @var{body})
26907 where @var{type} is a service type---e.g.,
26908 @code{guix-service-type}---and @var{variable} is an identifier that is
26909 bound within the @var{body} to the service parameters---e.g., a
26910 @code{guix-configuration} instance---of the original service of that
26913 The @var{body} should evaluate to the new service parameters, which will
26914 be used to configure the new service. This new service will replace the
26915 original in the resulting list. Because a service's service parameters
26916 are created using @code{define-record-type*}, you can write a succinct
26917 @var{body} that evaluates to the new service parameters by using the
26918 @code{inherit} feature that @code{define-record-type*} provides.
26920 @xref{Using the Configuration System}, for example usage.
26924 Next comes the programming interface for service types. This is
26925 something you want to know when writing new service definitions, but not
26926 necessarily when simply looking for ways to customize your
26927 @code{operating-system} declaration.
26929 @deftp {Data Type} service-type
26930 @cindex service type
26931 This is the representation of a @dfn{service type} (@pxref{Service Types
26936 This is a symbol, used only to simplify inspection and debugging.
26938 @item @code{extensions}
26939 A non-empty list of @code{<service-extension>} objects (see below).
26941 @item @code{compose} (default: @code{#f})
26942 If this is @code{#f}, then the service type denotes services that cannot
26943 be extended---i.e., services that do not receive ``values'' from other
26946 Otherwise, it must be a one-argument procedure. The procedure is called
26947 by @code{fold-services} and is passed a list of values collected from
26948 extensions. It may return any single value.
26950 @item @code{extend} (default: @code{#f})
26951 If this is @code{#f}, services of this type cannot be extended.
26953 Otherwise, it must be a two-argument procedure: @code{fold-services}
26954 calls it, passing it the initial value of the service as the first
26955 argument and the result of applying @code{compose} to the extension
26956 values as the second argument. It must return a value that is a valid
26957 parameter value for the service instance.
26960 @xref{Service Types and Services}, for examples.
26963 @deffn {Scheme Procedure} service-extension @var{target-type} @
26965 Return a new extension for services of type @var{target-type}.
26966 @var{compute} must be a one-argument procedure: @code{fold-services}
26967 calls it, passing it the value associated with the service that provides
26968 the extension; it must return a valid value for the target service.
26971 @deffn {Scheme Procedure} service-extension? @var{obj}
26972 Return true if @var{obj} is a service extension.
26975 Occasionally, you might want to simply extend an existing service. This
26976 involves creating a new service type and specifying the extension of
26977 interest, which can be verbose; the @code{simple-service} procedure
26978 provides a shorthand for this.
26980 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
26981 Return a service that extends @var{target} with @var{value}. This works
26982 by creating a singleton service type @var{name}, of which the returned
26983 service is an instance.
26985 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
26989 (simple-service 'my-mcron-job mcron-service-type
26990 #~(job '(next-hour (3)) "guix gc -F 2G"))
26994 At the core of the service abstraction lies the @code{fold-services}
26995 procedure, which is responsible for ``compiling'' a list of services
26996 down to a single directory that contains everything needed to boot and
26997 run the system---the directory shown by the @command{guix system build}
26998 command (@pxref{Invoking guix system}). In essence, it propagates
26999 service extensions down the service graph, updating each node parameters
27000 on the way, until it reaches the root node.
27002 @deffn {Scheme Procedure} fold-services @var{services} @
27003 [#:target-type @var{system-service-type}]
27004 Fold @var{services} by propagating their extensions down to the root of
27005 type @var{target-type}; return the root service adjusted accordingly.
27008 Lastly, the @code{(gnu services)} module also defines several essential
27009 service types, some of which are listed below.
27011 @defvr {Scheme Variable} system-service-type
27012 This is the root of the service graph. It produces the system directory
27013 as returned by the @command{guix system build} command.
27016 @defvr {Scheme Variable} boot-service-type
27017 The type of the ``boot service'', which produces the @dfn{boot script}.
27018 The boot script is what the initial RAM disk runs when booting.
27021 @defvr {Scheme Variable} etc-service-type
27022 The type of the @file{/etc} service. This service is used to create
27023 files under @file{/etc} and can be extended by
27024 passing it name/file tuples such as:
27027 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
27030 In this example, the effect would be to add an @file{/etc/issue} file
27031 pointing to the given file.
27034 @defvr {Scheme Variable} setuid-program-service-type
27035 Type for the ``setuid-program service''. This service collects lists of
27036 executable file names, passed as gexps, and adds them to the set of
27037 setuid-root programs on the system (@pxref{Setuid Programs}).
27040 @defvr {Scheme Variable} profile-service-type
27041 Type of the service that populates the @dfn{system profile}---i.e., the
27042 programs under @file{/run/current-system/profile}. Other services can
27043 extend it by passing it lists of packages to add to the system profile.
27046 @cindex provenance tracking, of the operating system
27047 @defvr {Scheme Variable} provenance-service-type
27048 This is the type of the service that records @dfn{provenance meta-data}
27049 in the system itself. It creates several files under
27050 @file{/run/current-system}:
27054 This is a ``channel file'' that can be passed to @command{guix pull -C}
27055 or @command{guix time-machine -C}, and which describes the channels used
27056 to build the system, if that information was available
27057 (@pxref{Channels}).
27059 @item configuration.scm
27060 This is the file that was passed as the value for this
27061 @code{provenance-service-type} service. By default, @command{guix
27062 system reconfigure} automatically passes the OS configuration file it
27063 received on the command line.
27066 This contains the same information as the two other files but in a
27067 format that is more readily processable.
27070 In general, these two pieces of information (channels and configuration
27071 file) are enough to reproduce the operating system ``from source''.
27074 This information is necessary to rebuild your operating system, but it
27075 is not always sufficient. In particular, @file{configuration.scm}
27076 itself is insufficient if it is not self-contained---if it refers to
27077 external Guile modules or to extra files. If you want
27078 @file{configuration.scm} to be self-contained, we recommend that modules
27079 or files it refers to be part of a channel.
27081 Besides, provenance meta-data is ``silent'' in the sense that it does
27082 not change the bits contained in your system, @emph{except for the
27083 meta-data bits themselves}. Two different OS configurations or sets of
27084 channels can lead to the same system, bit-for-bit; when
27085 @code{provenance-service-type} is used, these two systems will have
27086 different meta-data and thus different store file names, which makes
27087 comparison less trivial.
27091 @node Shepherd Services
27092 @subsection Shepherd Services
27094 @cindex shepherd services
27096 @cindex init system
27097 The @code{(gnu services shepherd)} module provides a way to define
27098 services managed by the GNU@tie{}Shepherd, which is the
27099 initialization system---the first process that is started when the
27100 system boots, also known as PID@tie{}1
27101 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
27103 Services in the Shepherd can depend on each other. For instance, the
27104 SSH daemon may need to be started after the syslog daemon has been
27105 started, which in turn can only happen once all the file systems have
27106 been mounted. The simple operating system defined earlier (@pxref{Using
27107 the Configuration System}) results in a service graph like this:
27109 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
27111 You can actually generate such a graph for any operating system
27112 definition using the @command{guix system shepherd-graph} command
27113 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
27115 The @code{%shepherd-root-service} is a service object representing
27116 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
27117 by passing it lists of @code{<shepherd-service>} objects.
27119 @deftp {Data Type} shepherd-service
27120 The data type representing a service managed by the Shepherd.
27123 @item @code{provision}
27124 This is a list of symbols denoting what the service provides.
27126 These are the names that may be passed to @command{herd start},
27127 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
27128 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
27129 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
27131 @item @code{requirement} (default: @code{'()})
27132 List of symbols denoting the Shepherd services this one depends on.
27134 @cindex one-shot services, for the Shepherd
27135 @item @code{one-shot?} (default: @code{#f})
27136 Whether this service is @dfn{one-shot}. One-shot services stop immediately
27137 after their @code{start} action has completed. @xref{Slots of services,,,
27138 shepherd, The GNU Shepherd Manual}, for more info.
27140 @item @code{respawn?} (default: @code{#t})
27141 Whether to restart the service when it stops, for instance when the
27142 underlying process dies.
27145 @itemx @code{stop} (default: @code{#~(const #f)})
27146 The @code{start} and @code{stop} fields refer to the Shepherd's
27147 facilities to start and stop processes (@pxref{Service De- and
27148 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
27149 G-expressions that get expanded in the Shepherd configuration file
27150 (@pxref{G-Expressions}).
27152 @item @code{actions} (default: @code{'()})
27153 @cindex actions, of Shepherd services
27154 This is a list of @code{shepherd-action} objects (see below) defining
27155 @dfn{actions} supported by the service, in addition to the standard
27156 @code{start} and @code{stop} actions. Actions listed here become available as
27157 @command{herd} sub-commands:
27160 herd @var{action} @var{service} [@var{arguments}@dots{}]
27163 @item @code{auto-start?} (default: @code{#t})
27164 Whether this service should be started automatically by the Shepherd. If it
27165 is @code{#f} the service has to be started manually with @code{herd start}.
27167 @item @code{documentation}
27168 A documentation string, as shown when running:
27171 herd doc @var{service-name}
27174 where @var{service-name} is one of the symbols in @code{provision}
27175 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
27177 @item @code{modules} (default: @code{%default-modules})
27178 This is the list of modules that must be in scope when @code{start} and
27179 @code{stop} are evaluated.
27184 @deftp {Data Type} shepherd-action
27185 This is the data type that defines additional actions implemented by a
27186 Shepherd service (see above).
27190 Symbol naming the action.
27192 @item documentation
27193 This is a documentation string for the action. It can be viewed by running:
27196 herd doc @var{service} action @var{action}
27200 This should be a gexp that evaluates to a procedure of at least one argument,
27201 which is the ``running value'' of the service (@pxref{Slots of services,,,
27202 shepherd, The GNU Shepherd Manual}).
27205 The following example defines an action called @code{say-hello} that kindly
27211 (documentation "Say hi!")
27212 (procedure #~(lambda (running . args)
27213 (format #t "Hello, friend! arguments: ~s\n"
27218 Assuming this action is added to the @code{example} service, then you can do:
27221 # herd say-hello example
27222 Hello, friend! arguments: ()
27223 # herd say-hello example a b c
27224 Hello, friend! arguments: ("a" "b" "c")
27227 This, as you can see, is a fairly sophisticated way to say hello.
27228 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
27232 @defvr {Scheme Variable} shepherd-root-service-type
27233 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
27235 This is the service type that extensions target when they want to create
27236 shepherd services (@pxref{Service Types and Services}, for an example).
27237 Each extension must pass a list of @code{<shepherd-service>}.
27240 @defvr {Scheme Variable} %shepherd-root-service
27241 This service represents PID@tie{}1.
27245 @node Documentation
27246 @chapter Documentation
27248 @cindex documentation, searching for
27249 @cindex searching for documentation
27250 @cindex Info, documentation format
27252 @cindex manual pages
27253 In most cases packages installed with Guix come with documentation.
27254 There are two main documentation formats: ``Info'', a browseable
27255 hypertext format used for GNU software, and ``manual pages'' (or ``man
27256 pages''), the linear documentation format traditionally found on Unix.
27257 Info manuals are accessed with the @command{info} command or with Emacs,
27258 and man pages are accessed using @command{man}.
27260 You can look for documentation of software installed on your system by
27261 keyword. For example, the following command searches for information
27262 about ``TLS'' in Info manuals:
27266 "(emacs)Network Security" -- STARTTLS
27267 "(emacs)Network Security" -- TLS
27268 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
27269 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
27274 The command below searches for the same keyword in man pages:
27278 SSL (7) - OpenSSL SSL/TLS library
27279 certtool (1) - GnuTLS certificate tool
27283 These searches are purely local to your computer so you have the
27284 guarantee that documentation you find corresponds to what you have
27285 actually installed, you can access it off-line, and your privacy is
27288 Once you have these results, you can view the relevant documentation by
27292 $ info "(gnutls)Core TLS API"
27302 Info manuals contain sections and indices as well as hyperlinks like
27303 those found in Web pages. The @command{info} reader (@pxref{Top, Info
27304 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
27305 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
27306 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
27307 Introduction}, for an introduction to Info navigation.
27309 @node Installing Debugging Files
27310 @chapter Installing Debugging Files
27312 @cindex debugging files
27313 Program binaries, as produced by the GCC compilers for instance, are
27314 typically written in the ELF format, with a section containing
27315 @dfn{debugging information}. Debugging information is what allows the
27316 debugger, GDB, to map binary code to source code; it is required to
27317 debug a compiled program in good conditions.
27319 The problem with debugging information is that is takes up a fair amount
27320 of disk space. For example, debugging information for the GNU C Library
27321 weighs in at more than 60 MiB. Thus, as a user, keeping all the
27322 debugging info of all the installed programs is usually not an option.
27323 Yet, space savings should not come at the cost of an impediment to
27324 debugging---especially in the GNU system, which should make it easier
27325 for users to exert their computing freedom (@pxref{GNU Distribution}).
27327 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
27328 mechanism that allows users to get the best of both worlds: debugging
27329 information can be stripped from the binaries and stored in separate
27330 files. GDB is then able to load debugging information from those files,
27331 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
27334 The GNU distribution takes advantage of this by storing debugging
27335 information in the @code{lib/debug} sub-directory of a separate package
27336 output unimaginatively called @code{debug} (@pxref{Packages with
27337 Multiple Outputs}). Users can choose to install the @code{debug} output
27338 of a package when they need it. For instance, the following command
27339 installs the debugging information for the GNU C Library and for GNU
27343 guix install glibc:debug guile:debug
27346 GDB must then be told to look for debug files in the user's profile, by
27347 setting the @code{debug-file-directory} variable (consider setting it
27348 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
27352 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
27355 From there on, GDB will pick up debugging information from the
27356 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
27358 In addition, you will most likely want GDB to be able to show the source
27359 code being debugged. To do that, you will have to unpack the source
27360 code of the package of interest (obtained with @code{guix build
27361 --source}, @pxref{Invoking guix build}), and to point GDB to that source
27362 directory using the @code{directory} command (@pxref{Source Path,
27363 @code{directory},, gdb, Debugging with GDB}).
27365 @c XXX: keep me up-to-date
27366 The @code{debug} output mechanism in Guix is implemented by the
27367 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
27368 opt-in---debugging information is available only for the packages
27369 with definitions explicitly declaring a @code{debug} output. This may be
27370 changed to opt-out in the future if our build farm servers can handle
27371 the load. To check whether a package has a @code{debug} output, use
27372 @command{guix package --list-available} (@pxref{Invoking guix package}).
27375 @node Security Updates
27376 @chapter Security Updates
27378 @cindex security updates
27379 @cindex security vulnerabilities
27380 Occasionally, important security vulnerabilities are discovered in software
27381 packages and must be patched. Guix developers try hard to keep track of
27382 known vulnerabilities and to apply fixes as soon as possible in the
27383 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
27384 containing only security updates.) The @command{guix lint} tool helps
27385 developers find out about vulnerable versions of software packages in the
27390 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
27391 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
27392 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
27396 @xref{Invoking guix lint}, for more information.
27398 Guix follows a functional
27399 package management discipline (@pxref{Introduction}), which implies
27400 that, when a package is changed, @emph{every package that depends on it}
27401 must be rebuilt. This can significantly slow down the deployment of
27402 fixes in core packages such as libc or Bash, since basically the whole
27403 distribution would need to be rebuilt. Using pre-built binaries helps
27404 (@pxref{Substitutes}), but deployment may still take more time than
27408 To address this, Guix implements @dfn{grafts}, a mechanism that allows
27409 for fast deployment of critical updates without the costs associated
27410 with a whole-distribution rebuild. The idea is to rebuild only the
27411 package that needs to be patched, and then to ``graft'' it onto packages
27412 explicitly installed by the user and that were previously referring to
27413 the original package. The cost of grafting is typically very low, and
27414 order of magnitudes lower than a full rebuild of the dependency chain.
27416 @cindex replacements of packages, for grafts
27417 For instance, suppose a security update needs to be applied to Bash.
27418 Guix developers will provide a package definition for the ``fixed''
27419 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
27420 Packages}). Then, the original package definition is augmented with a
27421 @code{replacement} field pointing to the package containing the bug fix:
27428 (replacement bash-fixed)))
27431 From there on, any package depending directly or indirectly on Bash---as
27432 reported by @command{guix gc --requisites} (@pxref{Invoking guix
27433 gc})---that is installed is automatically ``rewritten'' to refer to
27434 @code{bash-fixed} instead of @code{bash}. This grafting process takes
27435 time proportional to the size of the package, usually less than a
27436 minute for an ``average'' package on a recent machine. Grafting is
27437 recursive: when an indirect dependency requires grafting, then grafting
27438 ``propagates'' up to the package that the user is installing.
27440 Currently, the length of the name and version of the graft and that of
27441 the package it replaces (@code{bash-fixed} and @code{bash} in the example
27442 above) must be equal. This restriction mostly comes from the fact that
27443 grafting works by patching files, including binary files, directly.
27444 Other restrictions may apply: for instance, when adding a graft to a
27445 package providing a shared library, the original shared library and its
27446 replacement must have the same @code{SONAME} and be binary-compatible.
27448 The @option{--no-grafts} command-line option allows you to forcefully
27449 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
27453 guix build bash --no-grafts
27457 returns the store file name of the original Bash, whereas:
27464 returns the store file name of the ``fixed'', replacement Bash. This
27465 allows you to distinguish between the two variants of Bash.
27467 To verify which Bash your whole profile refers to, you can run
27468 (@pxref{Invoking guix gc}):
27471 guix gc -R `readlink -f ~/.guix-profile` | grep bash
27475 @dots{} and compare the store file names that you get with those above.
27476 Likewise for a complete Guix system generation:
27479 guix gc -R `guix system build my-config.scm` | grep bash
27482 Lastly, to check which Bash running processes are using, you can use the
27483 @command{lsof} command:
27486 lsof | grep /gnu/store/.*bash
27490 @node Bootstrapping
27491 @chapter Bootstrapping
27493 @c Adapted from the ELS 2013 paper.
27495 @cindex bootstrapping
27497 Bootstrapping in our context refers to how the distribution gets built
27498 ``from nothing''. Remember that the build environment of a derivation
27499 contains nothing but its declared inputs (@pxref{Introduction}). So
27500 there's an obvious chicken-and-egg problem: how does the first package
27501 get built? How does the first compiler get compiled? Note that this is
27502 a question of interest only to the curious hacker, not to the regular
27503 user, so you can shamelessly skip this section if you consider yourself
27504 a ``regular user''.
27506 @cindex bootstrap binaries
27507 The GNU system is primarily made of C code, with libc at its core. The
27508 GNU build system itself assumes the availability of a Bourne shell and
27509 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
27510 `grep'. Furthermore, build programs---programs that run
27511 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
27512 (@pxref{Derivations}). Consequently, to be able to build anything at
27513 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
27514 Binutils, libc, and the other packages mentioned above---the
27515 @dfn{bootstrap binaries}.
27517 These bootstrap binaries are ``taken for granted'', though we can also
27518 re-create them if needed (more on that later).
27520 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
27521 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
27524 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
27525 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
27528 @node Reduced Binary Seed Bootstrap
27529 @section The Reduced Binary Seed Bootstrap
27531 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
27532 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
27533 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
27534 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
27535 ``taken for granted.''
27537 Taking these binaries for granted means that we consider them to be a correct
27538 and trustworthy `seed' for building the complete system. Therein lies a
27539 problem: the current combined size of these bootstrap binaries is about 250MB
27540 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
27541 these is next to impossible.
27543 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
27544 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
27545 Bootstrap'' and while we are working towards that goal it would be hyperbole
27546 to use that term for what we do now.}.
27548 The Reduced Binary Seed bootstrap removes the most critical tools---from a
27549 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
27550 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
27551 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
27552 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
27553 these new binary seeds and a new set of
27555 packages@footnote{@c
27570 gcc-mesboot1-wrapper,
27571 glibc-headers-mesboot,
27575 gcc-mesboot-wrapper.
27578 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
27579 From here on the more traditional bootstrap process resumes. This approach
27580 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
27581 reduce this further. If you are interested, join us on @code{#bootstrappable}
27582 on the Freenode IRC network.
27584 @c ./pre-inst-env guix graph --type=bag -e '(begin (use-modules (guix packages)) (%current-system "i686-linux") (@@ (gnu packages commencement) gcc-mesboot))' > doc/images/gcc-mesboot-bag-graph.dot
27585 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
27587 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
27588 compiler used to build the rest of GuixSD.
27590 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
27592 @node Preparing to Use the Bootstrap Binaries
27593 @section Preparing to Use the Bootstrap Binaries
27595 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
27596 @c large image, it's hard to scroll. Oh well.
27597 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
27599 The figure above shows the very beginning of the dependency graph of the
27600 distribution, corresponding to the package definitions of the @code{(gnu
27601 packages bootstrap)} module. A similar figure can be generated with
27602 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
27605 guix graph -t derivation \
27606 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
27607 | dot -Tps > gcc.ps
27610 or, for the Reduced Binary Seed bootstrap
27613 guix graph -t derivation \
27614 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
27615 | dot -Tps > mes.ps
27618 At this level of detail, things are
27619 slightly complex. First, Guile itself consists of an ELF executable,
27620 along with many source and compiled Scheme files that are dynamically
27621 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
27622 tarball shown in this graph. This tarball is part of Guix's ``source''
27623 distribution, and gets inserted into the store with @code{add-to-store}
27624 (@pxref{The Store}).
27626 But how do we write a derivation that unpacks this tarball and adds it
27627 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
27628 derivation---the first one that gets built---uses @code{bash} as its
27629 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
27630 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
27631 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
27632 the Guix source distribution, whose sole purpose is to allow the Guile
27633 tarball to be unpacked.
27635 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
27636 Guile that can be used to run subsequent build programs. Its first task
27637 is to download tarballs containing the other pre-built binaries---this
27638 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
27639 @code{ftp-client.scm} are used for this purpose. The
27640 @code{module-import.drv} derivations import those modules in a directory
27641 in the store, using the original layout. The
27642 @code{module-import-compiled.drv} derivations compile those modules, and
27643 write them in an output directory with the right layout. This
27644 corresponds to the @code{#:modules} argument of
27645 @code{build-expression->derivation} (@pxref{Derivations}).
27647 Finally, the various tarballs are unpacked by the derivations
27648 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
27649 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
27650 point we have a working C tool chain.
27652 @unnumberedsec Building the Build Tools
27654 Bootstrapping is complete when we have a full tool chain that does not
27655 depend on the pre-built bootstrap tools discussed above. This
27656 no-dependency requirement is verified by checking whether the files of
27657 the final tool chain contain references to the @file{/gnu/store}
27658 directories of the bootstrap inputs. The process that leads to this
27659 ``final'' tool chain is described by the package definitions found in
27660 the @code{(gnu packages commencement)} module.
27662 The @command{guix graph} command allows us to ``zoom out'' compared to
27663 the graph above, by looking at the level of package objects instead of
27664 individual derivations---remember that a package may translate to
27665 several derivations, typically one derivation to download its source,
27666 one to build the Guile modules it needs, and one to actually build the
27667 package from source. The command:
27670 guix graph -t bag \
27671 -e '(@@@@ (gnu packages commencement)
27672 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
27676 produces the dependency graph leading to the ``final'' C
27677 library@footnote{You may notice the @code{glibc-intermediate} label,
27678 suggesting that it is not @emph{quite} final, but as a good
27679 approximation, we will consider it final.}, depicted below.
27681 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
27683 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
27684 The first tool that gets built with the bootstrap binaries is
27685 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
27686 for all the following packages. From there Findutils and Diffutils get
27689 Then come the first-stage Binutils and GCC, built as pseudo cross
27690 tools---i.e., with @code{--target} equal to @code{--host}. They are
27691 used to build libc. Thanks to this cross-build trick, this libc is
27692 guaranteed not to hold any reference to the initial tool chain.
27694 From there the final Binutils and GCC (not shown above) are built.
27696 from the final Binutils, and links programs against the just-built libc.
27697 This tool chain is used to build the other packages used by Guix and by
27698 the GNU Build System: Guile, Bash, Coreutils, etc.
27700 And voilà! At this point we have the complete set of build tools that
27701 the GNU Build System expects. These are in the @code{%final-inputs}
27702 variable of the @code{(gnu packages commencement)} module, and are
27703 implicitly used by any package that uses @code{gnu-build-system}
27704 (@pxref{Build Systems, @code{gnu-build-system}}).
27707 @unnumberedsec Building the Bootstrap Binaries
27709 @cindex bootstrap binaries
27710 Because the final tool chain does not depend on the bootstrap binaries,
27711 those rarely need to be updated. Nevertheless, it is useful to have an
27712 automated way to produce them, should an update occur, and this is what
27713 the @code{(gnu packages make-bootstrap)} module provides.
27715 The following command builds the tarballs containing the bootstrap binaries
27716 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
27717 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
27718 and Guile, and a tarball containing a mixture of Coreutils and other basic
27719 command-line tools):
27722 guix build bootstrap-tarballs
27725 The generated tarballs are those that should be referred to in the
27726 @code{(gnu packages bootstrap)} module mentioned at the beginning of
27729 Still here? Then perhaps by now you've started to wonder: when do we
27730 reach a fixed point? That is an interesting question! The answer is
27731 unknown, but if you would like to investigate further (and have
27732 significant computational and storage resources to do so), then let us
27735 @unnumberedsec Reducing the Set of Bootstrap Binaries
27737 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
27738 binary code! Why is that a problem? It's a problem because these big chunks
27739 of binary code are practically non-auditable, which makes it hard to establish
27740 what source code produced them. Every unauditable binary also leaves us
27741 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
27742 paper @emph{Reflections on Trusting Trust}.
27744 This is mitigated by the fact that our bootstrap binaries were generated
27745 from an earlier Guix revision. Nevertheless it lacks the level of
27746 transparency that we get in the rest of the package dependency graph,
27747 where Guix always gives us a source-to-binary mapping. Thus, our goal
27748 is to reduce the set of bootstrap binaries to the bare minimum.
27750 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
27751 on-going projects to do that. One of these is about replacing the
27752 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
27753 of increasing complexity, which could be built from source starting from
27754 a simple and auditable assembler.
27756 Our first major achievement is the replacement of of GCC, the GNU C Library
27757 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
27758 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
27759 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
27760 bootstrapped yet and thus we inject them as binary seeds. We call this the
27761 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
27762 binaries! Also, it has eliminated the C compiler binary; i686-linux and
27763 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
27765 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
27766 also looking at any other bootstrap binaries. Your help is welcome!
27769 @chapter Porting to a New Platform
27771 As discussed above, the GNU distribution is self-contained, and
27772 self-containment is achieved by relying on pre-built ``bootstrap
27773 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
27774 operating system kernel, CPU architecture, and application binary
27775 interface (ABI). Thus, to port the distribution to a platform that is
27776 not yet supported, one must build those bootstrap binaries, and update
27777 the @code{(gnu packages bootstrap)} module to use them on that platform.
27779 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
27780 When everything goes well, and assuming the GNU tool chain supports the
27781 target platform, this can be as simple as running a command like this
27785 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
27788 For this to work, the @code{glibc-dynamic-linker} procedure in
27789 @code{(gnu packages bootstrap)} must be augmented to return the right
27790 file name for libc's dynamic linker on that platform; likewise,
27791 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
27792 taught about the new platform.
27794 Once these are built, the @code{(gnu packages bootstrap)} module needs
27795 to be updated to refer to these binaries on the target platform. That
27796 is, the hashes and URLs of the bootstrap tarballs for the new platform
27797 must be added alongside those of the currently supported platforms. The
27798 bootstrap Guile tarball is treated specially: it is expected to be
27799 available locally, and @file{gnu/local.mk} has rules to download it for
27800 the supported architectures; a rule for the new platform must be added
27803 In practice, there may be some complications. First, it may be that the
27804 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
27805 above) is not recognized by all the GNU tools. Typically, glibc
27806 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
27807 configure flag (see @code{gcc.scm} for examples of how to handle this).
27808 Second, some of the required packages could fail to build for that
27809 platform. Lastly, the generated binaries could be broken for some
27812 @c *********************************************************************
27813 @include contributing.texi
27815 @c *********************************************************************
27816 @node Acknowledgments
27817 @chapter Acknowledgments
27819 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
27820 which was designed and
27821 implemented by Eelco Dolstra, with contributions from other people (see
27822 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
27823 management, and promoted unprecedented features, such as transactional
27824 package upgrades and rollbacks, per-user profiles, and referentially
27825 transparent build processes. Without this work, Guix would not exist.
27827 The Nix-based software distributions, Nixpkgs and NixOS, have also been
27828 an inspiration for Guix.
27830 GNU@tie{}Guix itself is a collective work with contributions from a
27831 number of people. See the @file{AUTHORS} file in Guix for more
27832 information on these fine people. The @file{THANKS} file lists people
27833 who have helped by reporting bugs, taking care of the infrastructure,
27834 providing artwork and themes, making suggestions, and more---thank you!
27837 @c *********************************************************************
27838 @node GNU Free Documentation License
27839 @appendix GNU Free Documentation License
27840 @cindex license, GNU Free Documentation License
27841 @include fdl-1.3.texi
27843 @c *********************************************************************
27844 @node Concept Index
27845 @unnumbered Concept Index
27848 @node Programming Index
27849 @unnumbered Programming Index
27850 @syncodeindex tp fn
27851 @syncodeindex vr fn
27856 @c Local Variables:
27857 @c ispell-local-dictionary: "american";