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, 2020 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, 2020 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, 2019 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, 2019 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 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@*
72 Copyright @copyright{} 2020 Leo Prikler@*
74 Permission is granted to copy, distribute and/or modify this document
75 under the terms of the GNU Free Documentation License, Version 1.3 or
76 any later version published by the Free Software Foundation; with no
77 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
78 copy of the license is included in the section entitled ``GNU Free
79 Documentation License''.
82 @dircategory System administration
84 * Guix: (guix). Manage installed software and system configuration.
85 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
86 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
87 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
88 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
89 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
92 @dircategory Software development
94 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
95 * guix build: (guix)Invoking guix build. Building packages.
96 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
100 @title GNU Guix Reference Manual
101 @subtitle Using the GNU Guix Functional Package Manager
102 @author The GNU Guix Developers
105 @vskip 0pt plus 1filll
106 Edition @value{EDITION} @*
114 @c *********************************************************************
118 This document describes GNU Guix version @value{VERSION}, a functional
119 package management tool written for the GNU system.
121 @c TRANSLATORS: You can replace the following paragraph with information on
122 @c how to join your own translation team and how to report issues with the
124 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
125 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
126 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
127 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
128 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
129 would like to translate it in your native language, consider joining the
130 @uref{https://translationproject.org/domain/guix-manual.html, Translation
134 * Introduction:: What is Guix about?
135 * Installation:: Installing Guix.
136 * System Installation:: Installing the whole operating system.
137 * Package Management:: Package installation, upgrade, etc.
138 * Development:: Guix-aided software development.
139 * Programming Interface:: Using Guix in Scheme.
140 * Utilities:: Package management commands.
141 * System Configuration:: Configuring the operating system.
142 * Documentation:: Browsing software user manuals.
143 * Installing Debugging Files:: Feeding the debugger.
144 * Security Updates:: Deploying security fixes quickly.
145 * Bootstrapping:: GNU/Linux built from scratch.
146 * Porting:: Targeting another platform or kernel.
147 * Contributing:: Your help needed!
149 * Acknowledgments:: Thanks!
150 * GNU Free Documentation License:: The license of this manual.
151 * Concept Index:: Concepts.
152 * Programming Index:: Data types, functions, and variables.
155 --- The Detailed Node Listing ---
159 * Managing Software the Guix Way:: What's special.
160 * GNU Distribution:: The packages and tools.
164 * Binary Installation:: Getting Guix running in no time!
165 * Requirements:: Software needed to build and run Guix.
166 * Running the Test Suite:: Testing Guix.
167 * Setting Up the Daemon:: Preparing the build daemon's environment.
168 * Invoking guix-daemon:: Running the build daemon.
169 * Application Setup:: Application-specific setup.
171 Setting Up the Daemon
173 * Build Environment Setup:: Preparing the isolated build environment.
174 * Daemon Offload Setup:: Offloading builds to remote machines.
175 * SELinux Support:: Using an SELinux policy for the daemon.
179 * Limitations:: What you can expect.
180 * Hardware Considerations:: Supported hardware.
181 * USB Stick and DVD Installation:: Preparing the installation medium.
182 * Preparing for Installation:: Networking, partitioning, etc.
183 * Guided Graphical Installation:: Easy graphical installation.
184 * Manual Installation:: Manual installation for wizards.
185 * After System Installation:: When installation succeeded.
186 * Installing Guix in a VM:: Guix System playground.
187 * Building the Installation Image:: How this comes to be.
191 * Keyboard Layout and Networking and Partitioning:: Initial setup.
192 * Proceeding with the Installation:: Installing.
196 * Features:: How Guix will make your life brighter.
197 * Invoking guix package:: Package installation, removal, etc.
198 * Substitutes:: Downloading pre-built binaries.
199 * Packages with Multiple Outputs:: Single source package, multiple outputs.
200 * Invoking guix gc:: Running the garbage collector.
201 * Invoking guix pull:: Fetching the latest Guix and distribution.
202 * Channels:: Customizing the package collection.
203 * Invoking guix time-machine:: Running an older revision of Guix.
204 * Inferiors:: Interacting with another revision of Guix.
205 * Invoking guix describe:: Display information about your Guix revision.
206 * Invoking guix archive:: Exporting and importing store files.
210 * Official Substitute Server:: One particular source of substitutes.
211 * Substitute Server Authorization:: How to enable or disable substitutes.
212 * Substitute Authentication:: How Guix verifies substitutes.
213 * Proxy Settings:: How to get substitutes via proxy.
214 * Substitution Failure:: What happens when substitution fails.
215 * On Trusting Binaries:: How can you trust that binary blob?
219 * Invoking guix environment:: Setting up development environments.
220 * Invoking guix pack:: Creating software bundles.
222 Programming Interface
224 * Package Modules:: Packages from the programmer's viewpoint.
225 * Defining Packages:: Defining new packages.
226 * Build Systems:: Specifying how packages are built.
227 * The Store:: Manipulating the package store.
228 * Derivations:: Low-level interface to package derivations.
229 * The Store Monad:: Purely functional interface to the store.
230 * G-Expressions:: Manipulating build expressions.
231 * Invoking guix repl:: Fiddling with Guix interactively.
235 * package Reference:: The package data type.
236 * origin Reference:: The origin data type.
240 * Invoking guix build:: Building packages from the command line.
241 * Invoking guix edit:: Editing package definitions.
242 * Invoking guix download:: Downloading a file and printing its hash.
243 * Invoking guix hash:: Computing the cryptographic hash of a file.
244 * Invoking guix import:: Importing package definitions.
245 * Invoking guix refresh:: Updating package definitions.
246 * Invoking guix lint:: Finding errors in package definitions.
247 * Invoking guix size:: Profiling disk usage.
248 * Invoking guix graph:: Visualizing the graph of packages.
249 * Invoking guix publish:: Sharing substitutes.
250 * Invoking guix challenge:: Challenging substitute servers.
251 * Invoking guix copy:: Copying to and from a remote store.
252 * Invoking guix container:: Process isolation.
253 * Invoking guix weather:: Assessing substitute availability.
254 * Invoking guix processes:: Listing client processes.
256 Invoking @command{guix build}
258 * Common Build Options:: Build options for most commands.
259 * Package Transformation Options:: Creating variants of packages.
260 * Additional Build Options:: Options specific to 'guix build'.
261 * Debugging Build Failures:: Real life packaging experience.
265 * Using the Configuration System:: Customizing your GNU system.
266 * operating-system Reference:: Detail of operating-system declarations.
267 * File Systems:: Configuring file system mounts.
268 * Mapped Devices:: Block device extra processing.
269 * User Accounts:: Specifying user accounts.
270 * Keyboard Layout:: How the system interprets key strokes.
271 * Locales:: Language and cultural convention settings.
272 * Services:: Specifying system services.
273 * Setuid Programs:: Programs running with root privileges.
274 * X.509 Certificates:: Authenticating HTTPS servers.
275 * Name Service Switch:: Configuring libc's name service switch.
276 * Initial RAM Disk:: Linux-Libre bootstrapping.
277 * Bootloader Configuration:: Configuring the boot loader.
278 * Invoking guix system:: Instantiating a system configuration.
279 * Invoking guix deploy:: Deploying a system configuration to a remote host.
280 * Running Guix in a VM:: How to run Guix System in a virtual machine.
281 * Defining Services:: Adding new service definitions.
285 * Base Services:: Essential system services.
286 * Scheduled Job Execution:: The mcron service.
287 * Log Rotation:: The rottlog service.
288 * Networking Services:: Network setup, SSH daemon, etc.
289 * X Window:: Graphical display.
290 * Printing Services:: Local and remote printer support.
291 * Desktop Services:: D-Bus and desktop services.
292 * Sound Services:: ALSA and Pulseaudio services.
293 * Database Services:: SQL databases, key-value stores, etc.
294 * Mail Services:: IMAP, POP3, SMTP, and all that.
295 * Messaging Services:: Messaging services.
296 * Telephony Services:: Telephony services.
297 * Monitoring Services:: Monitoring services.
298 * Kerberos Services:: Kerberos services.
299 * Web Services:: Web servers.
300 * Certificate Services:: TLS certificates via Let's Encrypt.
301 * DNS Services:: DNS daemons.
302 * VPN Services:: VPN daemons.
303 * Network File System:: NFS related services.
304 * Continuous Integration:: The Cuirass service.
305 * Power Management Services:: Extending battery life.
306 * Audio Services:: The MPD.
307 * Virtualization Services:: Virtualization services.
308 * Version Control Services:: Providing remote access to Git repositories.
309 * Game Services:: Game servers.
310 * PAM Mount Service:: Service to mount volumes when logging in.
311 * Miscellaneous Services:: Other services.
315 * Service Composition:: The model for composing services.
316 * Service Types and Services:: Types and services.
317 * Service Reference:: API reference.
318 * Shepherd Services:: A particular type of service.
323 @c *********************************************************************
325 @chapter Introduction
328 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
329 using the international phonetic alphabet (IPA).} is a package
330 management tool for and distribution of the GNU system.
331 Guix makes it easy for unprivileged
332 users to install, upgrade, or remove software packages, to roll back to a
333 previous package set, to build packages from source, and generally
334 assists with the creation and maintenance of software environments.
337 @cindex GuixSD, now Guix System
338 @cindex Guix System Distribution, now Guix System
339 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
340 complements the available tools without interference (@pxref{Installation}),
341 or you can use it as a standalone operating system distribution,
342 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
343 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
344 group everything under the ``Guix'' banner since, after all, Guix System is
345 readily available through the @command{guix system} command, even if you're
346 using a different distro underneath!}. @xref{GNU Distribution}.
349 * Managing Software the Guix Way:: What's special.
350 * GNU Distribution:: The packages and tools.
353 @node Managing Software the Guix Way
354 @section Managing Software the Guix Way
356 @cindex user interfaces
357 Guix provides a command-line package management interface
358 (@pxref{Package Management}), tools to help with software development
359 (@pxref{Development}), command-line utilities for more advanced usage,
360 (@pxref{Utilities}), as well as Scheme programming interfaces
361 (@pxref{Programming Interface}).
363 Its @dfn{build daemon} is responsible for building packages on behalf of
364 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
365 binaries from authorized sources (@pxref{Substitutes}).
367 @cindex extensibility of the distribution
368 @cindex customization, of packages
369 Guix includes package definitions for many GNU and non-GNU packages, all
370 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
371 user's computing freedom}. It is @emph{extensible}: users can write
372 their own package definitions (@pxref{Defining Packages}) and make them
373 available as independent package modules (@pxref{Package Modules}). It
374 is also @emph{customizable}: users can @emph{derive} specialized package
375 definitions from existing ones, including from the command line
376 (@pxref{Package Transformation Options}).
378 @cindex functional package management
380 Under the hood, Guix implements the @dfn{functional package management}
381 discipline pioneered by Nix (@pxref{Acknowledgments}).
382 In Guix, the package build and installation process is seen
383 as a @emph{function}, in the mathematical sense. That function takes inputs,
384 such as build scripts, a compiler, and libraries, and
385 returns an installed package. As a pure function, its result depends
386 solely on its inputs---for instance, it cannot refer to software or
387 scripts that were not explicitly passed as inputs. A build function
388 always produces the same result when passed a given set of inputs. It
389 cannot alter the environment of the running system in
390 any way; for instance, it cannot create, modify, or delete files outside
391 of its build and installation directories. This is achieved by running
392 build processes in isolated environments (or @dfn{containers}), where only their
393 explicit inputs are visible.
396 The result of package build functions is @dfn{cached} in the file
397 system, in a special directory called @dfn{the store} (@pxref{The
398 Store}). Each package is installed in a directory of its own in the
399 store---by default under @file{/gnu/store}. The directory name contains
400 a hash of all the inputs used to build that package; thus, changing an
401 input yields a different directory name.
403 This approach is the foundation for the salient features of Guix: support
404 for transactional package upgrade and rollback, per-user installation, and
405 garbage collection of packages (@pxref{Features}).
408 @node GNU Distribution
409 @section GNU Distribution
412 Guix comes with a distribution of the GNU system consisting entirely of
413 free software@footnote{The term ``free'' here refers to the
414 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
415 users of that software}.}. The
416 distribution can be installed on its own (@pxref{System Installation}),
417 but it is also possible to install Guix as a package manager on top of
418 an installed GNU/Linux system (@pxref{Installation}). When we need to
419 distinguish between the two, we refer to the standalone distribution as
422 The distribution provides core GNU packages such as GNU libc, GCC, and
423 Binutils, as well as many GNU and non-GNU applications. The complete
424 list of available packages can be browsed
425 @url{https://www.gnu.org/software/guix/packages,on-line} or by
426 running @command{guix package} (@pxref{Invoking guix package}):
429 guix package --list-available
432 Our goal is to provide a practical 100% free software distribution of
433 Linux-based and other variants of GNU, with a focus on the promotion and
434 tight integration of GNU components, and an emphasis on programs and
435 tools that help users exert that freedom.
437 Packages are currently available on the following platforms:
442 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
445 Intel 32-bit architecture (IA32), Linux-Libre kernel;
448 ARMv7-A architecture with hard float, Thumb-2 and NEON,
449 using the EABI hard-float application binary interface (ABI),
450 and Linux-Libre kernel.
453 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
456 little-endian 64-bit MIPS processors, specifically the Loongson series,
457 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
458 supported; in particular, the project's build farms no longer provide
459 substitutes for this architecture.
463 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
464 configuration and Guix takes care of instantiating the configuration in a
465 transactional, reproducible, and stateless fashion (@pxref{System
466 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
467 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
468 Manual}), the well-known GNU utilities and tool chain, as well as the
469 graphical environment or system services of your choice.
471 Guix System is available on all the above platforms except
472 @code{mips64el-linux}.
475 For information on porting to other architectures or kernels,
478 Building this distribution is a cooperative effort, and you are invited
479 to join! @xref{Contributing}, for information about how you can help.
482 @c *********************************************************************
484 @chapter Installation
486 @cindex installing Guix
489 We recommend the use of this
490 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
491 shell installer script} to install Guix on top of a running GNU/Linux system,
492 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
493 with the installation of the package manager, which can be done on top of a
494 running GNU/Linux system. If, instead, you want to install the complete GNU
495 operating system, @pxref{System Installation}.} The script automates the
496 download, installation, and initial configuration of Guix. It should be run
500 @cindex foreign distro
501 @cindex directories related to foreign distro
502 When installed on a foreign distro, GNU@tie{}Guix complements the available
503 tools without interference. Its data lives exclusively in two directories,
504 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
505 such as @file{/etc}, are left untouched.
507 Once installed, Guix can be updated by running @command{guix pull}
508 (@pxref{Invoking guix pull}).
510 If you prefer to perform the installation steps manually or want to tweak
511 them, you may find the following subsections useful. They describe the
512 software requirements of Guix, as well as how to install it manually and get
516 * Binary Installation:: Getting Guix running in no time!
517 * Requirements:: Software needed to build and run Guix.
518 * Running the Test Suite:: Testing Guix.
519 * Setting Up the Daemon:: Preparing the build daemon's environment.
520 * Invoking guix-daemon:: Running the build daemon.
521 * Application Setup:: Application-specific setup.
522 * Upgrading Guix:: Upgrading Guix and its build daemon.
525 @node Binary Installation
526 @section Binary Installation
528 @cindex installing Guix from binaries
529 @cindex installer script
530 This section describes how to install Guix on an arbitrary system from a
531 self-contained tarball providing binaries for Guix and for all its
532 dependencies. This is often quicker than installing from source, which
533 is described in the next sections. The only requirement is to have
536 @c Note duplicated from the ``Installation'' node.
538 We recommend the use of this
539 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
540 shell installer script}. The script automates the download, installation, and
541 initial configuration steps described below. It should be run as the root
545 Installing goes along these lines:
549 @cindex downloading Guix binary
550 Download the binary tarball from
551 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
552 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
553 already running the kernel Linux, and so on.
555 @c The following is somewhat duplicated in ``System Installation''.
556 Make sure to download the associated @file{.sig} file and to verify the
557 authenticity of the tarball against it, along these lines:
560 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
561 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
564 If that command fails because you do not have the required public key,
565 then run this command to import it:
568 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
569 -qO - | gpg --import -
573 and rerun the @code{gpg --verify} command.
575 Take note that a warning like ``This key is not certified with a trusted
576 signature!'' is normal.
578 @c end authentication part
581 Now, you need to become the @code{root} user. Depending on your distribution,
582 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
586 # tar --warning=no-timestamp -xf \
587 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
588 # mv var/guix /var/ && mv gnu /
591 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
592 The latter contains a ready-to-use profile for @code{root} (see next
595 Do @emph{not} unpack the tarball on a working Guix system since that
596 would overwrite its own essential files.
598 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
599 not emit warnings about ``implausibly old time stamps'' (such
600 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
602 They stem from the fact that all the
603 files in the archive have their modification time set to zero (which
604 means January 1st, 1970.) This is done on purpose to make sure the
605 archive content is independent of its creation time, thus making it
609 Make the profile available under @file{~root/.config/guix/current}, which is
610 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
613 # mkdir -p ~root/.config/guix
614 # ln -sf /var/guix/profiles/per-user/root/current-guix \
615 ~root/.config/guix/current
618 Source @file{etc/profile} to augment @code{PATH} and other relevant
619 environment variables:
622 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
623 source $GUIX_PROFILE/etc/profile
627 Create the group and user accounts for build users as explained below
628 (@pxref{Build Environment Setup}).
631 Run the daemon, and set it to automatically start on boot.
633 If your host distro uses the systemd init system, this can be achieved
636 @c Versions of systemd that supported symlinked service files are not
637 @c yet widely deployed, so we should suggest that users copy the service
640 @c See this thread for more information:
641 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
644 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
646 # systemctl start guix-daemon && systemctl enable guix-daemon
649 If your host distro uses the Upstart init system:
652 # initctl reload-configuration
653 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
658 Otherwise, you can still start the daemon manually with:
661 # ~root/.config/guix/current/bin/guix-daemon \
662 --build-users-group=guixbuild
666 Make the @command{guix} command available to other users on the machine,
670 # mkdir -p /usr/local/bin
672 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
675 It is also a good idea to make the Info version of this manual available
679 # mkdir -p /usr/local/share/info
680 # cd /usr/local/share/info
681 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
685 That way, assuming @file{/usr/local/share/info} is in the search path,
686 running @command{info guix} will open this manual (@pxref{Other Info
687 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
691 @cindex substitutes, authorization thereof
692 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
693 (@pxref{Substitutes}), authorize them:
696 # guix archive --authorize < \
697 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
701 Each user may need to perform a few additional steps to make their Guix
702 environment ready for use, @pxref{Application Setup}.
705 Voilà, the installation is complete!
707 You can confirm that Guix is working by installing a sample package into
714 The binary installation tarball can be (re)produced and verified simply
715 by running the following command in the Guix source tree:
718 make guix-binary.@var{system}.tar.xz
722 ...@: which, in turn, runs:
725 guix pack -s @var{system} --localstatedir \
726 --profile-name=current-guix guix
729 @xref{Invoking guix pack}, for more info on this handy tool.
732 @section Requirements
734 This section lists requirements when building Guix from source. The
735 build procedure for Guix is the same as for other GNU software, and is
736 not covered here. Please see the files @file{README} and @file{INSTALL}
737 in the Guix source tree for additional details.
739 @cindex official website
740 GNU Guix is available for download from its website at
741 @url{https://www.gnu.org/software/guix/}.
743 GNU Guix depends on the following packages:
746 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
747 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
750 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
751 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
752 Guile,, gnutls-guile, GnuTLS-Guile});
754 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
757 @c FIXME: Specify a version number once a release has been made.
758 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
760 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
761 @item @url{https://zlib.net, zlib};
762 @item @url{https://www.gnu.org/software/make/, GNU Make}.
765 The following dependencies are optional:
769 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
770 Support for build offloading (@pxref{Daemon Offload Setup}) and
771 @command{guix copy} (@pxref{Invoking guix copy}) depends on
772 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
773 version 0.10.2 or later.
776 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
777 substitutes can be used and @command{guix publish} can compress substitutes
781 When @url{http://www.bzip.org, libbz2} is available,
782 @command{guix-daemon} can use it to compress build logs.
785 Unless @code{--disable-daemon} was passed to @command{configure}, the
786 following packages are also needed:
789 @item @url{https://gnupg.org/, GNU libgcrypt};
790 @item @url{https://sqlite.org, SQLite 3};
791 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
795 @cindex state directory
796 When configuring Guix on a system that already has a Guix installation,
797 be sure to specify the same state directory as the existing installation
798 using the @code{--localstatedir} option of the @command{configure}
799 script (@pxref{Directory Variables, @code{localstatedir},, standards,
800 GNU Coding Standards}). Usually, this @var{localstatedir} option is
801 set to the value @file{/var}. The @command{configure} script protects
802 against unintended misconfiguration of @var{localstatedir} so you do not
803 inadvertently corrupt your store (@pxref{The Store}).
805 @node Running the Test Suite
806 @section Running the Test Suite
809 After a successful @command{configure} and @code{make} run, it is a good
810 idea to run the test suite. It can help catch issues with the setup or
811 environment, or bugs in Guix itself---and really, reporting test
812 failures is a good way to help improve the software. To run the test
819 Test cases can run in parallel: you can use the @code{-j} option of
820 GNU@tie{}make to speed things up. The first run may take a few minutes
821 on a recent machine; subsequent runs will be faster because the store
822 that is created for test purposes will already have various things in
825 It is also possible to run a subset of the tests by defining the
826 @code{TESTS} makefile variable as in this example:
829 make check TESTS="tests/store.scm tests/cpio.scm"
832 By default, tests results are displayed at a file level. In order to
833 see the details of every individual test cases, it is possible to define
834 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
837 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
840 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
841 @file{test-suite.log} file. Please specify the Guix version being used
842 as well as version numbers of the dependencies (@pxref{Requirements}) in
845 Guix also comes with a whole-system test suite that tests complete
846 Guix System instances. It can only run on systems where
847 Guix is already installed, using:
854 or, again, by defining @code{TESTS} to select a subset of tests to run:
857 make check-system TESTS="basic mcron"
860 These system tests are defined in the @code{(gnu tests @dots{})}
861 modules. They work by running the operating systems under test with
862 lightweight instrumentation in a virtual machine (VM). They can be
863 computationally intensive or rather cheap, depending on whether
864 substitutes are available for their dependencies (@pxref{Substitutes}).
865 Some of them require a lot of storage space to hold VM images.
867 Again in case of test failures, please send @email{bug-guix@@gnu.org}
870 @node Setting Up the Daemon
871 @section Setting Up the Daemon
874 Operations such as building a package or running the garbage collector
875 are all performed by a specialized process, the @dfn{build daemon}, on
876 behalf of clients. Only the daemon may access the store and its
877 associated database. Thus, any operation that manipulates the store
878 goes through the daemon. For instance, command-line tools such as
879 @command{guix package} and @command{guix build} communicate with the
880 daemon (@i{via} remote procedure calls) to instruct it what to do.
882 The following sections explain how to prepare the build daemon's
883 environment. See also @ref{Substitutes}, for information on how to allow
884 the daemon to download pre-built binaries.
887 * Build Environment Setup:: Preparing the isolated build environment.
888 * Daemon Offload Setup:: Offloading builds to remote machines.
889 * SELinux Support:: Using an SELinux policy for the daemon.
892 @node Build Environment Setup
893 @subsection Build Environment Setup
895 @cindex build environment
896 In a standard multi-user setup, Guix and its daemon---the
897 @command{guix-daemon} program---are installed by the system
898 administrator; @file{/gnu/store} is owned by @code{root} and
899 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
900 Guix tools to build packages or otherwise access the store, and the
901 daemon will do it on their behalf, ensuring that the store is kept in a
902 consistent state, and allowing built packages to be shared among users.
905 When @command{guix-daemon} runs as @code{root}, you may not want package
906 build processes themselves to run as @code{root} too, for obvious
907 security reasons. To avoid that, a special pool of @dfn{build users}
908 should be created for use by build processes started by the daemon.
909 These build users need not have a shell and a home directory: they will
910 just be used when the daemon drops @code{root} privileges in build
911 processes. Having several such users allows the daemon to launch
912 distinct build processes under separate UIDs, which guarantees that they
913 do not interfere with each other---an essential feature since builds are
914 regarded as pure functions (@pxref{Introduction}).
916 On a GNU/Linux system, a build user pool may be created like this (using
917 Bash syntax and the @code{shadow} commands):
919 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
920 @c for why `-G' is needed.
922 # groupadd --system guixbuild
923 # for i in `seq -w 1 10`;
925 useradd -g guixbuild -G guixbuild \
926 -d /var/empty -s `which nologin` \
927 -c "Guix build user $i" --system \
933 The number of build users determines how many build jobs may run in
934 parallel, as specified by the @option{--max-jobs} option
935 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
936 @command{guix system vm} and related commands, you may need to add the
937 build users to the @code{kvm} group so they can access @file{/dev/kvm},
938 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
939 (@pxref{Invoking guix system}).
941 The @code{guix-daemon} program may then be run as @code{root} with the
942 following command@footnote{If your machine uses the systemd init system,
943 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
944 file in @file{/etc/systemd/system} will ensure that
945 @command{guix-daemon} is automatically started. Similarly, if your
946 machine uses the Upstart init system, drop the
947 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
948 file in @file{/etc/init}.}:
951 # guix-daemon --build-users-group=guixbuild
956 This way, the daemon starts build processes in a chroot, under one of
957 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
958 environment contains nothing but:
960 @c Keep this list in sync with libstore/build.cc! -----------------------
963 a minimal @code{/dev} directory, created mostly independently from the
964 host @code{/dev}@footnote{``Mostly'', because while the set of files
965 that appear in the chroot's @code{/dev} is fixed, most of these files
966 can only be created if the host has them.};
969 the @code{/proc} directory; it only shows the processes of the container
970 since a separate PID name space is used;
973 @file{/etc/passwd} with an entry for the current user and an entry for
977 @file{/etc/group} with an entry for the user's group;
980 @file{/etc/hosts} with an entry that maps @code{localhost} to
984 a writable @file{/tmp} directory.
987 You can influence the directory where the daemon stores build trees
988 @i{via} the @code{TMPDIR} environment variable. However, the build tree
989 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
990 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
991 This way, the value of @code{TMPDIR} does not leak inside build
992 environments, which avoids discrepancies in cases where build processes
993 capture the name of their build tree.
996 The daemon also honors the @code{http_proxy} environment variable for
997 HTTP downloads it performs, be it for fixed-output derivations
998 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1000 If you are installing Guix as an unprivileged user, it is still possible
1001 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1002 However, build processes will not be isolated from one another, and not
1003 from the rest of the system. Thus, build processes may interfere with
1004 each other, and may access programs, libraries, and other files
1005 available on the system---making it much harder to view them as
1006 @emph{pure} functions.
1009 @node Daemon Offload Setup
1010 @subsection Using the Offload Facility
1014 When desired, the build daemon can @dfn{offload} derivation builds to
1015 other machines running Guix, using the @code{offload} @dfn{build
1016 hook}@footnote{This feature is available only when
1017 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1018 present.}. When that
1019 feature is enabled, a list of user-specified build machines is read from
1020 @file{/etc/guix/machines.scm}; every time a build is requested, for
1021 instance via @code{guix build}, the daemon attempts to offload it to one
1022 of the machines that satisfy the constraints of the derivation, in
1023 particular its system type---e.g., @file{x86_64-linux}. Missing
1024 prerequisites for the build are copied over SSH to the target machine,
1025 which then proceeds with the build; upon success the output(s) of the
1026 build are copied back to the initial machine.
1028 The @file{/etc/guix/machines.scm} file typically looks like this:
1031 (list (build-machine
1032 (name "eightysix.example.org")
1033 (system "x86_64-linux")
1034 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1036 (speed 2.)) ;incredibly fast!
1039 (name "meeps.example.org")
1040 (system "mips64el-linux")
1041 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1044 (string-append (getenv "HOME")
1045 "/.ssh/identity-for-guix"))))
1049 In the example above we specify a list of two build machines, one for
1050 the @code{x86_64} architecture and one for the @code{mips64el}
1053 In fact, this file is---not surprisingly!---a Scheme file that is
1054 evaluated when the @code{offload} hook is started. Its return value
1055 must be a list of @code{build-machine} objects. While this example
1056 shows a fixed list of build machines, one could imagine, say, using
1057 DNS-SD to return a list of potential build machines discovered in the
1058 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1059 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1062 @deftp {Data Type} build-machine
1063 This data type represents build machines to which the daemon may offload
1064 builds. The important fields are:
1069 The host name of the remote machine.
1072 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1075 The user account to use when connecting to the remote machine over SSH.
1076 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1077 allow non-interactive logins.
1080 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1081 This is used to authenticate the machine when we connect to it. It is a
1082 long string that looks like this:
1085 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1088 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1089 key can be found in a file such as
1090 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1092 If the machine is running the SSH daemon of GNU@tie{}lsh,
1093 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1094 similar file. It can be converted to the OpenSSH format using
1095 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1098 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1099 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1104 A number of optional fields may be specified:
1108 @item @code{port} (default: @code{22})
1109 Port number of SSH server on the machine.
1111 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1112 The SSH private key file to use when connecting to the machine, in
1113 OpenSSH format. This key must not be protected with a passphrase.
1115 Note that the default value is the private key @emph{of the root
1116 account}. Make sure it exists if you use the default.
1118 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1119 @itemx @code{compression-level} (default: @code{3})
1120 The SSH-level compression methods and compression level requested.
1122 Note that offloading relies on SSH compression to reduce bandwidth usage
1123 when transferring files to and from build machines.
1125 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1126 File name of the Unix-domain socket @command{guix-daemon} is listening
1129 @item @code{parallel-builds} (default: @code{1})
1130 The number of builds that may run in parallel on the machine.
1132 @item @code{speed} (default: @code{1.0})
1133 A ``relative speed factor''. The offload scheduler will tend to prefer
1134 machines with a higher speed factor.
1136 @item @code{features} (default: @code{'()})
1137 A list of strings denoting specific features supported by the machine.
1138 An example is @code{"kvm"} for machines that have the KVM Linux modules
1139 and corresponding hardware support. Derivations can request features by
1140 name, and they will be scheduled on matching build machines.
1145 The @command{guix} command must be in the search path on the build
1146 machines. You can check whether this is the case by running:
1149 ssh build-machine guix repl --version
1152 There is one last thing to do once @file{machines.scm} is in place. As
1153 explained above, when offloading, files are transferred back and forth
1154 between the machine stores. For this to work, you first need to
1155 generate a key pair on each machine to allow the daemon to export signed
1156 archives of files from the store (@pxref{Invoking guix archive}):
1159 # guix archive --generate-key
1163 Each build machine must authorize the key of the master machine so that
1164 it accepts store items it receives from the master:
1167 # guix archive --authorize < master-public-key.txt
1171 Likewise, the master machine must authorize the key of each build machine.
1173 All the fuss with keys is here to express pairwise mutual trust
1174 relations between the master and the build machines. Concretely, when
1175 the master receives files from a build machine (and @i{vice versa}), its
1176 build daemon can make sure they are genuine, have not been tampered
1177 with, and that they are signed by an authorized key.
1179 @cindex offload test
1180 To test whether your setup is operational, run this command on the
1187 This will attempt to connect to each of the build machines specified in
1188 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1189 available on each machine, attempt to export to the machine and import
1190 from it, and report any error in the process.
1192 If you want to test a different machine file, just specify it on the
1196 # guix offload test machines-qualif.scm
1199 Last, you can test the subset of the machines whose name matches a
1200 regular expression like this:
1203 # guix offload test machines.scm '\.gnu\.org$'
1206 @cindex offload status
1207 To display the current load of all build hosts, run this command on the
1211 # guix offload status
1215 @node SELinux Support
1216 @subsection SELinux Support
1218 @cindex SELinux, daemon policy
1219 @cindex mandatory access control, SELinux
1220 @cindex security, guix-daemon
1221 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1222 can be installed on a system where SELinux is enabled, in order to label
1223 Guix files and to specify the expected behavior of the daemon. Since
1224 Guix System does not provide an SELinux base policy, the daemon policy cannot
1225 be used on Guix System.
1227 @subsubsection Installing the SELinux policy
1228 @cindex SELinux, policy installation
1229 To install the policy run this command as root:
1232 semodule -i etc/guix-daemon.cil
1235 Then relabel the file system with @code{restorecon} or by a different
1236 mechanism provided by your system.
1238 Once the policy is installed, the file system has been relabeled, and
1239 the daemon has been restarted, it should be running in the
1240 @code{guix_daemon_t} context. You can confirm this with the following
1244 ps -Zax | grep guix-daemon
1247 Monitor the SELinux log files as you run a command like @code{guix build
1248 hello} to convince yourself that SELinux permits all necessary
1251 @subsubsection Limitations
1252 @cindex SELinux, limitations
1254 This policy is not perfect. Here is a list of limitations or quirks
1255 that should be considered when deploying the provided SELinux policy for
1260 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1261 operations involve contexts that have anything to do with
1262 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1263 but it would be preferrable to define socket rules for only this label.
1266 @code{guix gc} cannot access arbitrary links to profiles. By design,
1267 the file label of the destination of a symlink is independent of the
1268 file label of the link itself. Although all profiles under
1269 $localstatedir are labelled, the links to these profiles inherit the
1270 label of the directory they are in. For links in the user’s home
1271 directory this will be @code{user_home_t}. But for links from the root
1272 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1273 directory, etc, this won’t work. @code{guix gc} would be prevented from
1274 reading and following these links.
1277 The daemon’s feature to listen for TCP connections might no longer work.
1278 This might require extra rules, because SELinux treats network sockets
1279 differently from files.
1282 Currently all files with a name matching the regular expression
1283 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1284 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1285 that name in any profile would be permitted to run in the
1286 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1287 build a package that provides this executable and convince a user to
1288 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1289 At that point SELinux could not prevent it from accessing files that are
1290 allowed for processes in that domain.
1292 We could generate a much more restrictive policy at installation time,
1293 so that only the @emph{exact} file name of the currently installed
1294 @code{guix-daemon} executable would be labelled with
1295 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1296 The downside is that root would have to install or upgrade the policy at
1297 installation time whenever the Guix package that provides the
1298 effectively running @code{guix-daemon} executable is upgraded.
1301 @node Invoking guix-daemon
1302 @section Invoking @command{guix-daemon}
1304 The @command{guix-daemon} program implements all the functionality to
1305 access the store. This includes launching build processes, running the
1306 garbage collector, querying the availability of a build result, etc. It
1307 is normally run as @code{root} like this:
1310 # guix-daemon --build-users-group=guixbuild
1314 For details on how to set it up, @pxref{Setting Up the Daemon}.
1317 @cindex container, build environment
1318 @cindex build environment
1319 @cindex reproducible builds
1320 By default, @command{guix-daemon} launches build processes under
1321 different UIDs, taken from the build group specified with
1322 @code{--build-users-group}. In addition, each build process is run in a
1323 chroot environment that only contains the subset of the store that the
1324 build process depends on, as specified by its derivation
1325 (@pxref{Programming Interface, derivation}), plus a set of specific
1326 system directories. By default, the latter contains @file{/dev} and
1327 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1328 @dfn{container}: in addition to having its own file system tree, it has
1329 a separate mount name space, its own PID name space, network name space,
1330 etc. This helps achieve reproducible builds (@pxref{Features}).
1332 When the daemon performs a build on behalf of the user, it creates a
1333 build directory under @file{/tmp} or under the directory specified by
1334 its @code{TMPDIR} environment variable. This directory is shared with
1335 the container for the duration of the build, though within the container,
1336 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1338 The build directory is automatically deleted upon completion, unless the
1339 build failed and the client specified @option{--keep-failed}
1340 (@pxref{Invoking guix build, @option{--keep-failed}}).
1342 The daemon listens for connections and spawns one sub-process for each session
1343 started by a client (one of the @command{guix} sub-commands.) The
1344 @command{guix processes} command allows you to get an overview of the activity
1345 on your system by viewing each of the active sessions and clients.
1346 @xref{Invoking guix processes}, for more information.
1348 The following command-line options are supported:
1351 @item --build-users-group=@var{group}
1352 Take users from @var{group} to run build processes (@pxref{Setting Up
1353 the Daemon, build users}).
1355 @item --no-substitutes
1357 Do not use substitutes for build products. That is, always build things
1358 locally instead of allowing downloads of pre-built binaries
1359 (@pxref{Substitutes}).
1361 When the daemon runs with @code{--no-substitutes}, clients can still
1362 explicitly enable substitution @i{via} the @code{set-build-options}
1363 remote procedure call (@pxref{The Store}).
1365 @item --substitute-urls=@var{urls}
1366 @anchor{daemon-substitute-urls}
1367 Consider @var{urls} the default whitespace-separated list of substitute
1368 source URLs. When this option is omitted,
1369 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1371 This means that substitutes may be downloaded from @var{urls}, as long
1372 as they are signed by a trusted signature (@pxref{Substitutes}).
1376 Do not use offload builds to other machines (@pxref{Daemon Offload
1377 Setup}). That is, always build things locally instead of offloading
1378 builds to remote machines.
1380 @item --cache-failures
1381 Cache build failures. By default, only successful builds are cached.
1383 When this option is used, @command{guix gc --list-failures} can be used
1384 to query the set of store items marked as failed; @command{guix gc
1385 --clear-failures} removes store items from the set of cached failures.
1386 @xref{Invoking guix gc}.
1388 @item --cores=@var{n}
1390 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1393 The default value is @code{0}, but it may be overridden by clients, such
1394 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1397 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1398 in the build process, which can then use it to exploit internal
1399 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1401 @item --max-jobs=@var{n}
1403 Allow at most @var{n} build jobs in parallel. The default value is
1404 @code{1}. Setting it to @code{0} means that no builds will be performed
1405 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1406 Setup}), or simply fail.
1408 @item --max-silent-time=@var{seconds}
1409 When the build or substitution process remains silent for more than
1410 @var{seconds}, terminate it and report a build failure.
1412 The default value is @code{0}, which disables the timeout.
1414 The value specified here can be overridden by clients (@pxref{Common
1415 Build Options, @code{--max-silent-time}}).
1417 @item --timeout=@var{seconds}
1418 Likewise, when the build or substitution process lasts for more than
1419 @var{seconds}, terminate it and report a build failure.
1421 The default value is @code{0}, which disables the timeout.
1423 The value specified here can be overridden by clients (@pxref{Common
1424 Build Options, @code{--timeout}}).
1426 @item --rounds=@var{N}
1427 Build each derivation @var{n} times in a row, and raise an error if
1428 consecutive build results are not bit-for-bit identical. Note that this
1429 setting can be overridden by clients such as @command{guix build}
1430 (@pxref{Invoking guix build}).
1432 When used in conjunction with @option{--keep-failed}, the differing
1433 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1434 This makes it easy to look for differences between the two results.
1437 Produce debugging output.
1439 This is useful to debug daemon start-up issues, but then it may be
1440 overridden by clients, for example the @code{--verbosity} option of
1441 @command{guix build} (@pxref{Invoking guix build}).
1443 @item --chroot-directory=@var{dir}
1444 Add @var{dir} to the build chroot.
1446 Doing this may change the result of build processes---for instance if
1447 they use optional dependencies found in @var{dir} when it is available,
1448 and not otherwise. For that reason, it is not recommended to do so.
1449 Instead, make sure that each derivation declares all the inputs that it
1452 @item --disable-chroot
1453 Disable chroot builds.
1455 Using this option is not recommended since, again, it would allow build
1456 processes to gain access to undeclared dependencies. It is necessary,
1457 though, when @command{guix-daemon} is running under an unprivileged user
1460 @item --log-compression=@var{type}
1461 Compress build logs according to @var{type}, one of @code{gzip},
1462 @code{bzip2}, or @code{none}.
1464 Unless @code{--lose-logs} is used, all the build logs are kept in the
1465 @var{localstatedir}. To save space, the daemon automatically compresses
1466 them with bzip2 by default.
1468 @item --disable-deduplication
1469 @cindex deduplication
1470 Disable automatic file ``deduplication'' in the store.
1472 By default, files added to the store are automatically ``deduplicated'':
1473 if a newly added file is identical to another one found in the store,
1474 the daemon makes the new file a hard link to the other file. This can
1475 noticeably reduce disk usage, at the expense of slightly increased
1476 input/output load at the end of a build process. This option disables
1479 @item --gc-keep-outputs[=yes|no]
1480 Tell whether the garbage collector (GC) must keep outputs of live
1484 @cindex garbage collector roots
1485 When set to ``yes'', the GC will keep the outputs of any live derivation
1486 available in the store---the @code{.drv} files. The default is ``no'',
1487 meaning that derivation outputs are kept only if they are reachable from a GC
1488 root. @xref{Invoking guix gc}, for more on GC roots.
1490 @item --gc-keep-derivations[=yes|no]
1491 Tell whether the garbage collector (GC) must keep derivations
1492 corresponding to live outputs.
1494 When set to ``yes'', as is the case by default, the GC keeps
1495 derivations---i.e., @code{.drv} files---as long as at least one of their
1496 outputs is live. This allows users to keep track of the origins of
1497 items in their store. Setting it to ``no'' saves a bit of disk space.
1499 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1500 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1501 ``yes'' causes liveness to flow from derivations to outputs. When both are
1502 set to ``yes'', the effect is to keep all the build prerequisites (the
1503 sources, compiler, libraries, and other build-time tools) of live objects in
1504 the store, regardless of whether these prerequisites are reachable from a GC
1505 root. This is convenient for developers since it saves rebuilds or downloads.
1507 @item --impersonate-linux-2.6
1508 On Linux-based systems, impersonate Linux 2.6. This means that the
1509 kernel's @code{uname} system call will report 2.6 as the release number.
1511 This might be helpful to build programs that (usually wrongfully) depend
1512 on the kernel version number.
1515 Do not keep build logs. By default they are kept under
1516 @code{@var{localstatedir}/guix/log}.
1518 @item --system=@var{system}
1519 Assume @var{system} as the current system type. By default it is the
1520 architecture/kernel pair found at configure time, such as
1521 @code{x86_64-linux}.
1523 @item --listen=@var{endpoint}
1524 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1525 as the file name of a Unix-domain socket if it starts with
1526 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1527 host name or host name and port to listen to. Here are a few examples:
1530 @item --listen=/gnu/var/daemon
1531 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1532 creating it if needed.
1534 @item --listen=localhost
1535 @cindex daemon, remote access
1536 @cindex remote access to the daemon
1537 @cindex daemon, cluster setup
1538 @cindex clusters, daemon setup
1539 Listen for TCP connections on the network interface corresponding to
1540 @code{localhost}, on port 44146.
1542 @item --listen=128.0.0.42:1234
1543 Listen for TCP connections on the network interface corresponding to
1544 @code{128.0.0.42}, on port 1234.
1547 This option can be repeated multiple times, in which case
1548 @command{guix-daemon} accepts connections on all the specified
1549 endpoints. Users can tell client commands what endpoint to connect to
1550 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1551 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1554 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1555 @code{--listen=@var{host}} is suitable on local networks, such as
1556 clusters, where only trusted nodes may connect to the build daemon. In
1557 other cases where remote access to the daemon is needed, we recommend
1558 using Unix-domain sockets along with SSH.
1561 When @code{--listen} is omitted, @command{guix-daemon} listens for
1562 connections on the Unix-domain socket located at
1563 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1567 @node Application Setup
1568 @section Application Setup
1570 @cindex foreign distro
1571 When using Guix on top of GNU/Linux distribution other than Guix System---a
1572 so-called @dfn{foreign distro}---a few additional steps are needed to
1573 get everything in place. Here are some of them.
1577 @anchor{locales-and-locpath}
1578 @cindex locales, when not on Guix System
1580 @vindex GUIX_LOCPATH
1581 Packages installed @i{via} Guix will not use the locale data of the
1582 host system. Instead, you must first install one of the locale packages
1583 available with Guix and then define the @code{GUIX_LOCPATH} environment
1587 $ guix install glibc-locales
1588 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1591 Note that the @code{glibc-locales} package contains data for all the
1592 locales supported by the GNU@tie{}libc and weighs in at around
1593 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1594 limited to a few UTF-8 locales.
1596 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1597 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1598 Manual}). There are two important differences though:
1602 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1603 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1604 to make sure the programs of the foreign distro will not end up loading
1605 incompatible locale data.
1608 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1609 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1610 should your Guix profile contain a mixture of programs linked against
1611 different libc version, each libc version will only try to load locale
1612 data in the right format.
1615 This is important because the locale data format used by different libc
1616 versions may be incompatible.
1618 @subsection Name Service Switch
1620 @cindex name service switch, glibc
1621 @cindex NSS (name service switch), glibc
1622 @cindex nscd (name service caching daemon)
1623 @cindex name service caching daemon (nscd)
1624 When using Guix on a foreign distro, we @emph{strongly recommend} that
1625 the system run the GNU C library's @dfn{name service cache daemon},
1626 @command{nscd}, which should be listening on the
1627 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1628 installed with Guix may fail to look up host names or user accounts, or
1629 may even crash. The next paragraphs explain why.
1631 @cindex @file{nsswitch.conf}
1632 The GNU C library implements a @dfn{name service switch} (NSS), which is
1633 an extensible mechanism for ``name lookups'' in general: host name
1634 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1635 The GNU C Library Reference Manual}).
1637 @cindex Network information service (NIS)
1638 @cindex NIS (Network information service)
1639 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1640 lookup implementations: for example, the @code{nss-mdns} plugin allow
1641 resolution of @code{.local} host names, the @code{nis} plugin allows
1642 user account lookup using the Network information service (NIS), and so
1643 on. These extra ``lookup services'' are configured system-wide in
1644 @file{/etc/nsswitch.conf}, and all the programs running on the system
1645 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1648 When they perform a name lookup---for instance by calling the
1649 @code{getaddrinfo} function in C---applications first try to connect to
1650 the nscd; on success, nscd performs name lookups on their behalf. If
1651 the nscd is not running, then they perform the name lookup by
1652 themselves, by loading the name lookup services into their own address
1653 space and running it. These name lookup services---the
1654 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1655 the host system's C library, rather than from the C library the
1656 application is linked against (the C library coming from Guix).
1658 And this is where the problem is: if your application is linked against
1659 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1660 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1661 likely crash or have its name lookups fail unexpectedly.
1663 Running @command{nscd} on the system, among other advantages, eliminates
1664 this binary incompatibility problem because those @code{libnss_*.so}
1665 files are loaded in the @command{nscd} process, not in applications
1668 @subsection X11 Fonts
1671 The majority of graphical applications use Fontconfig to locate and
1672 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1673 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1674 by default. Thus, to allow graphical applications installed with Guix
1675 to display fonts, you have to install fonts with Guix as well.
1676 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1677 @code{font-gnu-freefont-ttf}.
1679 To display text written in Chinese languages, Japanese, or Korean in
1680 graphical applications, consider installing
1681 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1682 has multiple outputs, one per language family (@pxref{Packages with
1683 Multiple Outputs}). For instance, the following command installs fonts
1684 for Chinese languages:
1687 guix install font-adobe-source-han-sans:cn
1690 @cindex @code{xterm}
1691 Older programs such as @command{xterm} do not use Fontconfig and instead
1692 rely on server-side font rendering. Such programs require to specify a
1693 full name of a font using XLFD (X Logical Font Description), like this:
1696 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1699 To be able to use such full names for the TrueType fonts installed in
1700 your Guix profile, you need to extend the font path of the X server:
1702 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1703 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1705 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1708 @cindex @code{xlsfonts}
1709 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1710 to make sure your TrueType fonts are listed there.
1712 @cindex @code{fc-cache}
1714 After installing fonts you may have to refresh the font cache to use
1715 them in applications. The same applies when applications installed via
1716 Guix do not seem to find fonts. To force rebuilding of the font cache
1717 run @code{fc-cache -rv}. The @code{fc-cache} command is provided by
1718 the @code{fontconfig} package.
1720 @subsection X.509 Certificates
1722 @cindex @code{nss-certs}
1723 The @code{nss-certs} package provides X.509 certificates, which allow
1724 programs to authenticate Web servers accessed over HTTPS.
1726 When using Guix on a foreign distro, you can install this package and
1727 define the relevant environment variables so that packages know where to
1728 look for certificates. @xref{X.509 Certificates}, for detailed
1731 @subsection Emacs Packages
1733 @cindex @code{emacs}
1734 When you install Emacs packages with Guix, the elisp files may be placed
1735 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1737 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1738 directory exists because potentially there may exist thousands of Emacs
1739 packages and storing all their files in a single directory may not be
1740 reliable (because of name conflicts). So we think using a separate
1741 directory for each package is a good idea. It is very similar to how
1742 the Emacs package system organizes the file structure (@pxref{Package
1743 Files,,, emacs, The GNU Emacs Manual}).
1745 By default, Emacs (installed with Guix) ``knows'' where these packages
1746 are placed, so you do not need to perform any configuration. If, for
1747 some reason, you want to avoid auto-loading Emacs packages installed
1748 with Guix, you can do so by running Emacs with @code{--no-site-file}
1749 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1751 @subsection The GCC toolchain
1756 Guix offers individual compiler packages such as @code{gcc} but if you
1757 are in need of a complete toolchain for compiling and linking source
1758 code what you really want is the @code{gcc-toolchain} package. This
1759 package provides a complete GCC toolchain for C/C++ development,
1760 including GCC itself, the GNU C Library (headers and binaries, plus
1761 debugging symbols in the @code{debug} output), Binutils, and a linker
1764 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1765 passed to the linker, add corresponding @code{-rpath} arguments, and
1766 invoke the actual linker with this new set of arguments. You can instruct the
1767 wrapper to refuse to link against libraries not in the store by setting the
1768 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1770 @node Upgrading Guix
1771 @section Upgrading Guix
1773 @cindex Upgrading Guix, on a foreign distro
1775 To upgrade Guix, run:
1781 @xref{Invoking guix pull}, for more information.
1783 @cindex upgrading Guix for the root user, on a foreign distro
1784 @cindex upgrading the Guix daemon, on a foreign distro
1785 @cindex @command{guix pull} for the root user, on a foreign distro
1787 On a foreign distro, you can upgrade the build daemon by running:
1794 followed by (assuming your distro uses the systemd service management
1798 systemctl restart guix-daemon.service
1801 On Guix System, upgrading the daemon is achieved by reconfiguring the
1802 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1806 @c *********************************************************************
1807 @node System Installation
1808 @chapter System Installation
1810 @cindex installing Guix System
1811 @cindex Guix System, installation
1812 This section explains how to install Guix System
1813 on a machine. Guix, as a package manager, can
1814 also be installed on top of a running GNU/Linux system,
1815 @pxref{Installation}.
1819 @c This paragraph is for people reading this from tty2 of the
1820 @c installation image.
1821 You are reading this documentation with an Info reader. For details on
1822 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1823 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1824 Info}. Hit @kbd{l} afterwards to come back here.
1826 Alternately, run @command{info info} in another tty to keep the manual
1832 * Limitations:: What you can expect.
1833 * Hardware Considerations:: Supported hardware.
1834 * USB Stick and DVD Installation:: Preparing the installation medium.
1835 * Preparing for Installation:: Networking, partitioning, etc.
1836 * Guided Graphical Installation:: Easy graphical installation.
1837 * Manual Installation:: Manual installation for wizards.
1838 * After System Installation:: When installation succeeded.
1839 * Installing Guix in a VM:: Guix System playground.
1840 * Building the Installation Image:: How this comes to be.
1844 @section Limitations
1846 We consider Guix System to be ready for a wide range of ``desktop'' and server
1847 use cases. The reliability guarantees it provides---transactional upgrades
1848 and rollbacks, reproducibility---make it a solid foundation.
1850 Nevertheless, before you proceed with the installation, be aware of the
1851 following noteworthy limitations applicable to version @value{VERSION}:
1855 Support for the Logical Volume Manager (LVM) is missing.
1858 More and more system services are provided (@pxref{Services}), but some
1862 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1863 as well as a number of X11 window managers. However, KDE is currently
1867 More than a disclaimer, this is an invitation to report issues (and success
1868 stories!), and to join us in improving it. @xref{Contributing}, for more
1872 @node Hardware Considerations
1873 @section Hardware Considerations
1875 @cindex hardware support on Guix System
1876 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1877 builds around the kernel Linux-libre, which means that only hardware for
1878 which free software drivers and firmware exist is supported. Nowadays,
1879 a wide range of off-the-shelf hardware is supported on
1880 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1881 Ethernet controllers. Unfortunately, there are still areas where
1882 hardware vendors deny users control over their own computing, and such
1883 hardware is not supported on Guix System.
1885 @cindex WiFi, hardware support
1886 One of the main areas where free drivers or firmware are lacking is WiFi
1887 devices. WiFi devices known to work include those using Atheros chips
1888 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1889 driver, and those using Broadcom/AirForce chips (BCM43xx with
1890 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1891 Linux-libre driver. Free firmware exists for both and is available
1892 out-of-the-box on Guix System, as part of @code{%base-firmware}
1893 (@pxref{operating-system Reference, @code{firmware}}).
1895 @cindex RYF, Respects Your Freedom
1896 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1897 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1898 certification program for hardware products that respect your freedom
1899 and your privacy and ensure that you have control over your device. We
1900 encourage you to check the list of RYF-certified devices.
1902 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1903 web site. It contains a catalog of hardware devices with information
1904 about their support in GNU/Linux.
1907 @node USB Stick and DVD Installation
1908 @section USB Stick and DVD Installation
1910 An ISO-9660 installation image that can be written to a USB stick or
1911 burnt to a DVD can be downloaded from
1912 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1913 where @var{system} is one of:
1917 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1920 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1923 @c start duplication of authentication part from ``Binary Installation''
1924 Make sure to download the associated @file{.sig} file and to verify the
1925 authenticity of the image against it, along these lines:
1928 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1929 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1932 If that command fails because you do not have the required public key,
1933 then run this command to import it:
1936 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1937 -qO - | gpg --import -
1941 and rerun the @code{gpg --verify} command.
1943 Take note that a warning like ``This key is not certified with a trusted
1944 signature!'' is normal.
1948 This image contains the tools necessary for an installation.
1949 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1951 @unnumberedsubsec Copying to a USB Stick
1953 To copy the image to a USB stick, follow these steps:
1957 Decompress the image using the @command{xz} command:
1960 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1964 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1965 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1966 copy the image with:
1969 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1973 Access to @file{/dev/sdX} usually requires root privileges.
1976 @unnumberedsubsec Burning on a DVD
1978 To copy the image to a DVD, follow these steps:
1982 Decompress the image using the @command{xz} command:
1985 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1989 Insert a blank DVD into your machine, and determine
1990 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1991 copy the image with:
1994 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1997 Access to @file{/dev/srX} usually requires root privileges.
2000 @unnumberedsubsec Booting
2002 Once this is done, you should be able to reboot the system and boot from
2003 the USB stick or DVD. The latter usually requires you to get in the
2004 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2006 @xref{Installing Guix in a VM}, if, instead, you would like to install
2007 Guix System in a virtual machine (VM).
2010 @node Preparing for Installation
2011 @section Preparing for Installation
2013 Once you have booted, you can use the guided graphical installer, which makes
2014 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2015 if you are already familiar with GNU/Linux and if you want more control than
2016 what the graphical installer provides, you can choose the ``manual''
2017 installation process (@pxref{Manual Installation}).
2019 The graphical installer is available on TTY1. You can obtain root shells on
2020 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2021 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2022 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2023 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2024 which allows you to select text with the left mouse button and to paste it
2025 with the middle button.
2028 Installation requires access to the Internet so that any missing
2029 dependencies of your system configuration can be downloaded. See the
2030 ``Networking'' section below.
2033 @node Guided Graphical Installation
2034 @section Guided Graphical Installation
2036 The graphical installer is a text-based user interface. It will guide you,
2037 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2039 The first dialog boxes allow you to set up the system as you use it during the
2040 installation: you can choose the language, keyboard layout, and set up
2041 networking, which will be used during the installation. The image below shows
2042 the networking dialog.
2044 @image{images/installer-network,5in,, networking setup with the graphical installer}
2046 Later steps allow you to partition your hard disk, as shown in the image
2047 below, to choose whether or not to use encrypted file systems, to enter the
2048 host name and root password, and to create an additional account, among other
2051 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2053 Note that, at any time, the installer allows you to exit the current
2054 installation step and resume at a previous step, as show in the image below.
2056 @image{images/installer-resume,5in,, resuming the installation process}
2058 Once you're done, the installer produces an operating system configuration and
2059 displays it (@pxref{Using the Configuration System}). At that point you can
2060 hit ``OK'' and installation will proceed. On success, you can reboot into the
2061 new system and enjoy. @xref{After System Installation}, for what's next!
2064 @node Manual Installation
2065 @section Manual Installation
2067 This section describes how you would ``manually'' install GNU@tie{}Guix System
2068 on your machine. This option requires familiarity with GNU/Linux, with the
2069 shell, and with common administration tools. If you think this is not for
2070 you, consider using the guided graphical installer (@pxref{Guided Graphical
2073 The installation system provides root shells on TTYs 3 to 6; press
2074 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2075 many common tools needed to install the system. But it is also a full-blown
2076 Guix System, which means that you can install additional packages, should you
2077 need it, using @command{guix package} (@pxref{Invoking guix package}).
2080 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2081 * Proceeding with the Installation:: Installing.
2084 @node Keyboard Layout and Networking and Partitioning
2085 @subsection Keyboard Layout, Networking, and Partitioning
2087 Before you can install the system, you may want to adjust the keyboard layout,
2088 set up networking, and partition your target hard disk. This section will
2089 guide you through this.
2091 @subsubsection Keyboard Layout
2093 @cindex keyboard layout
2094 The installation image uses the US qwerty keyboard layout. If you want
2095 to change it, you can use the @command{loadkeys} command. For example,
2096 the following command selects the Dvorak keyboard layout:
2102 See the files under @file{/run/current-system/profile/share/keymaps} for
2103 a list of available keyboard layouts. Run @command{man loadkeys} for
2106 @subsubsection Networking
2108 Run the following command to see what your network interfaces are called:
2115 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2121 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2122 Wired interfaces have a name starting with @samp{e}; for example, the
2123 interface corresponding to the first on-board Ethernet controller is
2124 called @samp{eno1}. Wireless interfaces have a name starting with
2125 @samp{w}, like @samp{w1p2s0}.
2128 @item Wired connection
2129 To configure a wired network run the following command, substituting
2130 @var{interface} with the name of the wired interface you want to use.
2133 ifconfig @var{interface} up
2137 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2140 ip link set @var{interface} up
2143 @item Wireless connection
2146 To configure wireless networking, you can create a configuration file
2147 for the @command{wpa_supplicant} configuration tool (its location is not
2148 important) using one of the available text editors such as
2152 nano wpa_supplicant.conf
2155 As an example, the following stanza can go to this file and will work
2156 for many wireless networks, provided you give the actual SSID and
2157 passphrase for the network you are connecting to:
2161 ssid="@var{my-ssid}"
2163 psk="the network's secret passphrase"
2167 Start the wireless service and run it in the background with the
2168 following command (substitute @var{interface} with the name of the
2169 network interface you want to use):
2172 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2175 Run @command{man wpa_supplicant} for more information.
2179 At this point, you need to acquire an IP address. On a network where IP
2180 addresses are automatically assigned @i{via} DHCP, you can run:
2183 dhclient -v @var{interface}
2186 Try to ping a server to see if networking is up and running:
2192 Setting up network access is almost always a requirement because the
2193 image does not contain all the software and tools that may be needed.
2195 @cindex installing over SSH
2196 If you want to, you can continue the installation remotely by starting
2200 herd start ssh-daemon
2203 Make sure to either set a password with @command{passwd}, or configure
2204 OpenSSH public key authentication before logging in.
2206 @subsubsection Disk Partitioning
2208 Unless this has already been done, the next step is to partition, and
2209 then format the target partition(s).
2211 The installation image includes several partitioning tools, including
2212 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2213 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2214 the partition layout you want:
2220 If your disk uses the GUID Partition Table (GPT) format and you plan to
2221 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2222 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2225 @cindex EFI, installation
2226 @cindex UEFI, installation
2227 @cindex ESP, EFI system partition
2228 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2229 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2230 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2233 parted /dev/sda set 1 esp on
2237 @vindex grub-bootloader
2238 @vindex grub-efi-bootloader
2239 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2240 @file{/sys/firmware/efi} exists in the installation image, then you should
2241 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2242 Otherwise you should use the BIOS-based GRUB, known as
2243 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2247 Once you are done partitioning the target hard disk drive, you have to
2248 create a file system on the relevant partition(s)@footnote{Currently
2249 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2250 code that reads file system UUIDs and labels only works for these file system
2251 types.}. For the ESP, if you have one and assuming it is
2252 @file{/dev/sda1}, run:
2255 mkfs.fat -F32 /dev/sda1
2258 Preferably, assign file systems a label so that you can easily and
2259 reliably refer to them in @code{file-system} declarations (@pxref{File
2260 Systems}). This is typically done using the @code{-L} option of
2261 @command{mkfs.ext4} and related commands. So, assuming the target root
2262 partition lives at @file{/dev/sda2}, a file system with the label
2263 @code{my-root} can be created with:
2266 mkfs.ext4 -L my-root /dev/sda2
2269 @cindex encrypted disk
2270 If you are instead planning to encrypt the root partition, you can use
2271 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2272 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2273 @code{man cryptsetup}} for more information.) Assuming you want to
2274 store the root partition on @file{/dev/sda2}, the command sequence would
2275 be along these lines:
2278 cryptsetup luksFormat /dev/sda2
2279 cryptsetup open --type luks /dev/sda2 my-partition
2280 mkfs.ext4 -L my-root /dev/mapper/my-partition
2283 Once that is done, mount the target file system under @file{/mnt}
2284 with a command like (again, assuming @code{my-root} is the label of the
2288 mount LABEL=my-root /mnt
2291 Also mount any other file systems you would like to use on the target
2292 system relative to this path. If you have opted for @file{/boot/efi} as an
2293 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2294 found by @code{guix system init} afterwards.
2296 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2297 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2298 sure to initialize them with @command{mkswap}. Assuming you have one
2299 swap partition on @file{/dev/sda3}, you would run:
2306 Alternatively, you may use a swap file. For example, assuming that in
2307 the new system you want to use the file @file{/swapfile} as a swap file,
2308 you would run@footnote{This example will work for many types of file
2309 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2310 btrfs), the required steps may be different. For details, see the
2311 manual pages for @command{mkswap} and @command{swapon}.}:
2314 # This is 10 GiB of swap space. Adjust "count" to change the size.
2315 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2316 # For security, make the file readable and writable only by root.
2317 chmod 600 /mnt/swapfile
2318 mkswap /mnt/swapfile
2319 swapon /mnt/swapfile
2322 Note that if you have encrypted the root partition and created a swap
2323 file in its file system as described above, then the encryption also
2324 protects the swap file, just like any other file in that file system.
2326 @node Proceeding with the Installation
2327 @subsection Proceeding with the Installation
2329 With the target partitions ready and the target root mounted on
2330 @file{/mnt}, we're ready to go. First, run:
2333 herd start cow-store /mnt
2336 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2337 during the installation phase are written to the target disk on @file{/mnt}
2338 rather than kept in memory. This is necessary because the first phase of
2339 the @command{guix system init} command (see below) entails downloads or
2340 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2342 Next, you have to edit a file and
2343 provide the declaration of the operating system to be installed. To
2344 that end, the installation system comes with three text editors. We
2345 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2346 supports syntax highlighting and parentheses matching; other editors
2347 include GNU Zile (an Emacs clone), and
2348 nvi (a clone of the original BSD @command{vi} editor).
2349 We strongly recommend storing that file on the target root file system, say,
2350 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2351 configuration file once you have rebooted into the newly-installed system.
2353 @xref{Using the Configuration System}, for an overview of the
2354 configuration file. The example configurations discussed in that
2355 section are available under @file{/etc/configuration} in the
2356 installation image. Thus, to get started with a system configuration
2357 providing a graphical display server (a ``desktop'' system), you can run
2358 something along these lines:
2362 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2363 # nano /mnt/etc/config.scm
2366 You should pay attention to what your configuration file contains, and
2371 Make sure the @code{bootloader-configuration} form refers to the target
2372 you want to install GRUB on. It should mention @code{grub-bootloader} if
2373 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2374 for newer UEFI systems. For legacy systems, the @code{target} field
2375 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2376 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2377 currently mounted and a @code{file-system} entry is specified in your
2381 Be sure that your file system labels match the value of their respective
2382 @code{device} fields in your @code{file-system} configuration, assuming
2383 your @code{file-system} configuration uses the @code{file-system-label}
2384 procedure in its @code{device} field.
2387 If there are encrypted or RAID partitions, make sure to add a
2388 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2391 Once you are done preparing the configuration file, the new system must
2392 be initialized (remember that the target root file system is mounted
2396 guix system init /mnt/etc/config.scm /mnt
2400 This copies all the necessary files and installs GRUB on
2401 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2402 more information, @pxref{Invoking guix system}. This command may trigger
2403 downloads or builds of missing packages, which can take some time.
2405 Once that command has completed---and hopefully succeeded!---you can run
2406 @command{reboot} and boot into the new system. The @code{root} password
2407 in the new system is initially empty; other users' passwords need to be
2408 initialized by running the @command{passwd} command as @code{root},
2409 unless your configuration specifies otherwise
2410 (@pxref{user-account-password, user account passwords}).
2411 @xref{After System Installation}, for what's next!
2414 @node After System Installation
2415 @section After System Installation
2417 Success, you've now booted into Guix System! From then on, you can update the
2418 system whenever you want by running, say:
2422 sudo guix system reconfigure /etc/config.scm
2426 This builds a new system generation with the latest packages and services
2427 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2428 your system includes the latest security updates (@pxref{Security Updates}).
2430 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2432 @cindex sudo vs. @command{guix pull}
2433 Note that @command{sudo guix} runs your user's @command{guix} command and
2434 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2435 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2438 Join us on @code{#guix} on the Freenode IRC network or on
2439 @email{guix-devel@@gnu.org} to share your experience!
2442 @node Installing Guix in a VM
2443 @section Installing Guix in a Virtual Machine
2445 @cindex virtual machine, Guix System installation
2446 @cindex virtual private server (VPS)
2447 @cindex VPS (virtual private server)
2448 If you'd like to install Guix System in a virtual machine (VM) or on a
2449 virtual private server (VPS) rather than on your beloved machine, this
2452 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2453 disk image, follow these steps:
2457 First, retrieve and decompress the Guix system installation image as
2458 described previously (@pxref{USB Stick and DVD Installation}).
2461 Create a disk image that will hold the installed system. To make a
2462 qcow2-formatted disk image, use the @command{qemu-img} command:
2465 qemu-img create -f qcow2 guix-system.img 50G
2468 The resulting file will be much smaller than 50 GB (typically less than
2469 1 MB), but it will grow as the virtualized storage device is filled up.
2472 Boot the USB installation image in an VM:
2475 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2476 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2477 -drive file=guix-system.img \
2478 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2481 @code{-enable-kvm} is optional, but significantly improves performance,
2482 @pxref{Running Guix in a VM}.
2485 You're now root in the VM, proceed with the installation process.
2486 @xref{Preparing for Installation}, and follow the instructions.
2489 Once installation is complete, you can boot the system that's on your
2490 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2493 @node Building the Installation Image
2494 @section Building the Installation Image
2496 @cindex installation image
2497 The installation image described above was built using the @command{guix
2498 system} command, specifically:
2501 guix system disk-image --file-system-type=iso9660 \
2502 gnu/system/install.scm
2505 Have a look at @file{gnu/system/install.scm} in the source tree,
2506 and see also @ref{Invoking guix system} for more information
2507 about the installation image.
2509 @section Building the Installation Image for ARM Boards
2511 Many ARM boards require a specific variant of the
2512 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2514 If you build a disk image and the bootloader is not available otherwise
2515 (on another boot drive etc), it's advisable to build an image that
2516 includes the bootloader, specifically:
2519 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2522 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2523 board, a list of possible boards will be printed.
2525 @c *********************************************************************
2526 @node Package Management
2527 @chapter Package Management
2530 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2531 remove software packages, without having to know about their build
2532 procedures or dependencies. Guix also goes beyond this obvious set of
2535 This chapter describes the main features of Guix, as well as the
2536 package management tools it provides. Along with the command-line
2537 interface described below (@pxref{Invoking guix package, @code{guix
2538 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2539 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2540 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2544 guix install emacs-guix
2548 * Features:: How Guix will make your life brighter.
2549 * Invoking guix package:: Package installation, removal, etc.
2550 * Substitutes:: Downloading pre-built binaries.
2551 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2552 * Invoking guix gc:: Running the garbage collector.
2553 * Invoking guix pull:: Fetching the latest Guix and distribution.
2554 * Channels:: Customizing the package collection.
2555 * Invoking guix time-machine:: Running an older revision of Guix.
2556 * Inferiors:: Interacting with another revision of Guix.
2557 * Invoking guix describe:: Display information about your Guix revision.
2558 * Invoking guix archive:: Exporting and importing store files.
2564 When using Guix, each package ends up in the @dfn{package store}, in its
2565 own directory---something that resembles
2566 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2568 Instead of referring to these directories, users have their own
2569 @dfn{profile}, which points to the packages that they actually want to
2570 use. These profiles are stored within each user's home directory, at
2571 @code{$HOME/.guix-profile}.
2573 For example, @code{alice} installs GCC 4.7.2. As a result,
2574 @file{/home/alice/.guix-profile/bin/gcc} points to
2575 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2576 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2577 simply continues to point to
2578 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2579 coexist on the same system without any interference.
2581 The @command{guix package} command is the central tool to manage
2582 packages (@pxref{Invoking guix package}). It operates on the per-user
2583 profiles, and can be used @emph{with normal user privileges}.
2585 @cindex transactions
2586 The command provides the obvious install, remove, and upgrade
2587 operations. Each invocation is actually a @emph{transaction}: either
2588 the specified operation succeeds, or nothing happens. Thus, if the
2589 @command{guix package} process is terminated during the transaction,
2590 or if a power outage occurs during the transaction, then the user's
2591 profile remains in its previous state, and remains usable.
2593 In addition, any package transaction may be @emph{rolled back}. So, if,
2594 for example, an upgrade installs a new version of a package that turns
2595 out to have a serious bug, users may roll back to the previous instance
2596 of their profile, which was known to work well. Similarly, the global
2597 system configuration on Guix is subject to
2598 transactional upgrades and roll-back
2599 (@pxref{Using the Configuration System}).
2601 All packages in the package store may be @emph{garbage-collected}.
2602 Guix can determine which packages are still referenced by user
2603 profiles, and remove those that are provably no longer referenced
2604 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2605 generations of their profile so that the packages they refer to can be
2608 @cindex reproducibility
2609 @cindex reproducible builds
2610 Guix takes a @dfn{purely functional} approach to package
2611 management, as described in the introduction (@pxref{Introduction}).
2612 Each @file{/gnu/store} package directory name contains a hash of all the
2613 inputs that were used to build that package---compiler, libraries, build
2614 scripts, etc. This direct correspondence allows users to make sure a
2615 given package installation matches the current state of their
2616 distribution. It also helps maximize @dfn{build reproducibility}:
2617 thanks to the isolated build environments that are used, a given build
2618 is likely to yield bit-identical files when performed on different
2619 machines (@pxref{Invoking guix-daemon, container}).
2622 This foundation allows Guix to support @dfn{transparent binary/source
2623 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2624 available from an external source---a @dfn{substitute}, Guix just
2625 downloads it and unpacks it;
2626 otherwise, it builds the package from source, locally
2627 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2628 reproducible, users do not have to trust servers that provide
2629 substitutes: they can force a local build and @emph{challenge} providers
2630 (@pxref{Invoking guix challenge}).
2632 Control over the build environment is a feature that is also useful for
2633 developers. The @command{guix environment} command allows developers of
2634 a package to quickly set up the right development environment for their
2635 package, without having to manually install the dependencies of the
2636 package into their profile (@pxref{Invoking guix environment}).
2638 @cindex replication, of software environments
2639 @cindex provenance tracking, of software artifacts
2640 All of Guix and its package definitions is version-controlled, and
2641 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2642 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2643 Guix instance on a different machine or at a later point in time, which in
2644 turn allows you to @emph{replicate complete software environments}, while
2645 retaining precise @dfn{provenance tracking} of the software.
2647 @node Invoking guix package
2648 @section Invoking @command{guix package}
2650 @cindex installing packages
2651 @cindex removing packages
2652 @cindex package installation
2653 @cindex package removal
2654 The @command{guix package} command is the tool that allows users to
2655 install, upgrade, and remove packages, as well as rolling back to
2656 previous configurations. It operates only on the user's own profile,
2657 and works with normal user privileges (@pxref{Features}). Its syntax
2661 guix package @var{options}
2664 @cindex transactions
2665 Primarily, @var{options} specifies the operations to be performed during
2666 the transaction. Upon completion, a new profile is created, but
2667 previous @dfn{generations} of the profile remain available, should the user
2670 For example, to remove @code{lua} and install @code{guile} and
2671 @code{guile-cairo} in a single transaction:
2674 guix package -r lua -i guile guile-cairo
2677 @cindex aliases, for @command{guix package}
2678 For your convenience, we also provide the following aliases:
2682 @command{guix search} is an alias for @command{guix package -s},
2684 @command{guix install} is an alias for @command{guix package -i},
2686 @command{guix remove} is an alias for @command{guix package -r},
2688 @command{guix upgrade} is an alias for @command{guix package -u},
2690 and @command{guix show} is an alias for @command{guix package --show=}.
2693 These aliases are less expressive than @command{guix package} and provide
2694 fewer options, so in some cases you'll probably want to use @command{guix
2697 @command{guix package} also supports a @dfn{declarative approach}
2698 whereby the user specifies the exact set of packages to be available and
2699 passes it @i{via} the @option{--manifest} option
2700 (@pxref{profile-manifest, @option{--manifest}}).
2703 For each user, a symlink to the user's default profile is automatically
2704 created in @file{$HOME/.guix-profile}. This symlink always points to the
2705 current generation of the user's default profile. Thus, users can add
2706 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2707 variable, and so on.
2708 @cindex search paths
2709 If you are not using Guix System, consider adding the
2710 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2711 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2712 shells get all the right environment variable definitions:
2715 GUIX_PROFILE="$HOME/.guix-profile" ; \
2716 source "$HOME/.guix-profile/etc/profile"
2719 In a multi-user setup, user profiles are stored in a place registered as
2720 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2721 to (@pxref{Invoking guix gc}). That directory is normally
2722 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2723 @var{localstatedir} is the value passed to @code{configure} as
2724 @code{--localstatedir}, and @var{user} is the user name. The
2725 @file{per-user} directory is created when @command{guix-daemon} is
2726 started, and the @var{user} sub-directory is created by @command{guix
2729 The @var{options} can be among the following:
2733 @item --install=@var{package} @dots{}
2734 @itemx -i @var{package} @dots{}
2735 Install the specified @var{package}s.
2737 Each @var{package} may specify either a simple package name, such as
2738 @code{guile}, or a package name followed by an at-sign and version number,
2739 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2740 case, the newest version prefixed by @code{1.8} is selected.)
2742 If no version number is specified, the
2743 newest available version will be selected. In addition, @var{package}
2744 may contain a colon, followed by the name of one of the outputs of the
2745 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2746 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2747 name (and optionally version) are searched for among the GNU
2748 distribution modules (@pxref{Package Modules}).
2750 @cindex propagated inputs
2751 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2752 that automatically get installed along with the required package
2753 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2754 @code{package} objects}, for information about propagated inputs in
2755 package definitions).
2757 @anchor{package-cmd-propagated-inputs}
2758 An example is the GNU MPC library: its C header files refer to those of
2759 the GNU MPFR library, which in turn refer to those of the GMP library.
2760 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2761 in the profile; removing MPC also removes MPFR and GMP---unless they had
2762 also been explicitly installed by the user.
2764 Besides, packages sometimes rely on the definition of environment
2765 variables for their search paths (see explanation of
2766 @code{--search-paths} below). Any missing or possibly incorrect
2767 environment variable definitions are reported here.
2769 @item --install-from-expression=@var{exp}
2771 Install the package @var{exp} evaluates to.
2773 @var{exp} must be a Scheme expression that evaluates to a
2774 @code{<package>} object. This option is notably useful to disambiguate
2775 between same-named variants of a package, with expressions such as
2776 @code{(@@ (gnu packages base) guile-final)}.
2778 Note that this option installs the first output of the specified
2779 package, which may be insufficient when needing a specific output of a
2780 multiple-output package.
2782 @item --install-from-file=@var{file}
2783 @itemx -f @var{file}
2784 Install the package that the code within @var{file} evaluates to.
2786 As an example, @var{file} might contain a definition like this
2787 (@pxref{Defining Packages}):
2790 @include package-hello.scm
2793 Developers may find it useful to include such a @file{guix.scm} file
2794 in the root of their project source tree that can be used to test
2795 development snapshots and create reproducible development environments
2796 (@pxref{Invoking guix environment}).
2798 @item --remove=@var{package} @dots{}
2799 @itemx -r @var{package} @dots{}
2800 Remove the specified @var{package}s.
2802 As for @code{--install}, each @var{package} may specify a version number
2803 and/or output name in addition to the package name. For instance,
2804 @code{-r glibc:debug} would remove the @code{debug} output of
2807 @item --upgrade[=@var{regexp} @dots{}]
2808 @itemx -u [@var{regexp} @dots{}]
2809 @cindex upgrading packages
2810 Upgrade all the installed packages. If one or more @var{regexp}s are
2811 specified, upgrade only installed packages whose name matches a
2812 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2814 Note that this upgrades package to the latest version of packages found
2815 in the distribution currently installed. To update your distribution,
2816 you should regularly run @command{guix pull} (@pxref{Invoking guix
2819 @item --do-not-upgrade[=@var{regexp} @dots{}]
2820 When used together with the @code{--upgrade} option, do @emph{not}
2821 upgrade any packages whose name matches a @var{regexp}. For example, to
2822 upgrade all packages in the current profile except those containing the
2823 substring ``emacs'':
2826 $ guix package --upgrade . --do-not-upgrade emacs
2829 @item @anchor{profile-manifest}--manifest=@var{file}
2830 @itemx -m @var{file}
2831 @cindex profile declaration
2832 @cindex profile manifest
2833 Create a new generation of the profile from the manifest object
2834 returned by the Scheme code in @var{file}. This option can be repeated
2835 several times, in which case the manifests are concatenated.
2837 This allows you to @emph{declare} the profile's contents rather than
2838 constructing it through a sequence of @code{--install} and similar
2839 commands. The advantage is that @var{file} can be put under version
2840 control, copied to different machines to reproduce the same profile, and
2843 @c FIXME: Add reference to (guix profile) documentation when available.
2844 @var{file} must return a @dfn{manifest} object, which is roughly a list
2847 @findex packages->manifest
2849 (use-package-modules guile emacs)
2854 ;; Use a specific package output.
2855 (list guile-2.0 "debug")))
2858 @findex specifications->manifest
2859 In this example we have to know which modules define the @code{emacs}
2860 and @code{guile-2.0} variables to provide the right
2861 @code{use-package-modules} line, which can be cumbersome. We can
2862 instead provide regular package specifications and let
2863 @code{specifications->manifest} look up the corresponding package
2867 (specifications->manifest
2868 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2872 @cindex rolling back
2873 @cindex undoing transactions
2874 @cindex transactions, undoing
2875 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2876 the last transaction.
2878 When combined with options such as @code{--install}, roll back occurs
2879 before any other actions.
2881 When rolling back from the first generation that actually contains
2882 installed packages, the profile is made to point to the @dfn{zeroth
2883 generation}, which contains no files apart from its own metadata.
2885 After having rolled back, installing, removing, or upgrading packages
2886 overwrites previous future generations. Thus, the history of the
2887 generations in a profile is always linear.
2889 @item --switch-generation=@var{pattern}
2890 @itemx -S @var{pattern}
2892 Switch to a particular generation defined by @var{pattern}.
2894 @var{pattern} may be either a generation number or a number prefixed
2895 with ``+'' or ``-''. The latter means: move forward/backward by a
2896 specified number of generations. For example, if you want to return to
2897 the latest generation after @code{--roll-back}, use
2898 @code{--switch-generation=+1}.
2900 The difference between @code{--roll-back} and
2901 @code{--switch-generation=-1} is that @code{--switch-generation} will
2902 not make a zeroth generation, so if a specified generation does not
2903 exist, the current generation will not be changed.
2905 @item --search-paths[=@var{kind}]
2906 @cindex search paths
2907 Report environment variable definitions, in Bash syntax, that may be
2908 needed in order to use the set of installed packages. These environment
2909 variables are used to specify @dfn{search paths} for files used by some
2910 of the installed packages.
2912 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2913 environment variables to be defined so it can look for headers and
2914 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2915 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2916 library are installed in the profile, then @code{--search-paths} will
2917 suggest setting these variables to @code{@var{profile}/include} and
2918 @code{@var{profile}/lib}, respectively.
2920 The typical use case is to define these environment variables in the
2924 $ eval `guix package --search-paths`
2927 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2928 meaning that the returned environment variable definitions will either
2929 be exact settings, or prefixes or suffixes of the current value of these
2930 variables. When omitted, @var{kind} defaults to @code{exact}.
2932 This option can also be used to compute the @emph{combined} search paths
2933 of several profiles. Consider this example:
2936 $ guix package -p foo -i guile
2937 $ guix package -p bar -i guile-json
2938 $ guix package -p foo -p bar --search-paths
2941 The last command above reports about the @code{GUILE_LOAD_PATH}
2942 variable, even though, taken individually, neither @file{foo} nor
2943 @file{bar} would lead to that recommendation.
2946 @item --profile=@var{profile}
2947 @itemx -p @var{profile}
2948 Use @var{profile} instead of the user's default profile.
2950 @var{profile} must be the name of a file that will be created upon
2951 completion. Concretely, @var{profile} will be a mere symbolic link
2952 (``symlink'') pointing to the actual profile where packages are
2956 $ guix install hello -p ~/code/my-profile
2958 $ ~/code/my-profile/bin/hello
2962 All it takes to get rid of the profile is to remove this symlink and its
2963 siblings that point to specific generations:
2966 $ rm ~/code/my-profile ~/code/my-profile-*-link
2969 @item --list-profiles
2970 List all the user's profiles:
2973 $ guix package --list-profiles
2974 /home/charlie/.guix-profile
2975 /home/charlie/code/my-profile
2976 /home/charlie/code/devel-profile
2977 /home/charlie/tmp/test
2980 When running as root, list all the profiles of all the users.
2982 @cindex collisions, in a profile
2983 @cindex colliding packages in profiles
2984 @cindex profile collisions
2985 @item --allow-collisions
2986 Allow colliding packages in the new profile. Use at your own risk!
2988 By default, @command{guix package} reports as an error @dfn{collisions}
2989 in the profile. Collisions happen when two or more different versions
2990 or variants of a given package end up in the profile.
2993 Use the bootstrap Guile to build the profile. This option is only
2994 useful to distribution developers.
2998 In addition to these actions, @command{guix package} supports the
2999 following options to query the current state of a profile, or the
3000 availability of packages:
3004 @item --search=@var{regexp}
3005 @itemx -s @var{regexp}
3006 @cindex searching for packages
3007 List the available packages whose name, synopsis, or description matches
3008 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3009 Print all the metadata of matching packages in
3010 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3011 GNU recutils manual}).
3013 This allows specific fields to be extracted using the @command{recsel}
3014 command, for instance:
3017 $ guix package -s malloc | recsel -p name,version,relevance
3031 Similarly, to show the name of all the packages available under the
3032 terms of the GNU@tie{}LGPL version 3:
3035 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3042 It is also possible to refine search results using several @code{-s} flags to
3043 @command{guix package}, or several arguments to @command{guix search}. For
3044 example, the following command returns a list of board games (this time using
3045 the @command{guix search} alias):
3048 $ guix search '\<board\>' game | recsel -p name
3053 If we were to omit @code{-s game}, we would also get software packages
3054 that deal with printed circuit boards; removing the angle brackets
3055 around @code{board} would further add packages that have to do with
3058 And now for a more elaborate example. The following command searches
3059 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3060 libraries, and prints the name and synopsis of the matching packages:
3063 $ guix search crypto library | \
3064 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3068 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3069 information on @dfn{selection expressions} for @code{recsel -e}.
3071 @item --show=@var{package}
3072 Show details about @var{package}, taken from the list of available packages, in
3073 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3077 $ guix package --show=python | recsel -p name,version
3085 You may also specify the full name of a package to only get details about a
3086 specific version of it (this time using the @command{guix show} alias):
3088 $ guix show python@@3.4 | recsel -p name,version
3095 @item --list-installed[=@var{regexp}]
3096 @itemx -I [@var{regexp}]
3097 List the currently installed packages in the specified profile, with the
3098 most recently installed packages shown last. When @var{regexp} is
3099 specified, list only installed packages whose name matches @var{regexp}.
3101 For each installed package, print the following items, separated by
3102 tabs: the package name, its version string, the part of the package that
3103 is installed (for instance, @code{out} for the default output,
3104 @code{include} for its headers, etc.), and the path of this package in
3107 @item --list-available[=@var{regexp}]
3108 @itemx -A [@var{regexp}]
3109 List packages currently available in the distribution for this system
3110 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3111 installed packages whose name matches @var{regexp}.
3113 For each package, print the following items separated by tabs: its name,
3114 its version string, the parts of the package (@pxref{Packages with
3115 Multiple Outputs}), and the source location of its definition.
3117 @item --list-generations[=@var{pattern}]
3118 @itemx -l [@var{pattern}]
3120 Return a list of generations along with their creation dates; for each
3121 generation, show the installed packages, with the most recently
3122 installed packages shown last. Note that the zeroth generation is never
3125 For each installed package, print the following items, separated by
3126 tabs: the name of a package, its version string, the part of the package
3127 that is installed (@pxref{Packages with Multiple Outputs}), and the
3128 location of this package in the store.
3130 When @var{pattern} is used, the command returns only matching
3131 generations. Valid patterns include:
3134 @item @emph{Integers and comma-separated integers}. Both patterns denote
3135 generation numbers. For instance, @code{--list-generations=1} returns
3138 And @code{--list-generations=1,8,2} outputs three generations in the
3139 specified order. Neither spaces nor trailing commas are allowed.
3141 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3142 specified generations and everything in between. Note that the start of
3143 a range must be smaller than its end.
3145 It is also possible to omit the endpoint. For example,
3146 @code{--list-generations=2..}, returns all generations starting from the
3149 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3150 or months by passing an integer along with the first letter of the
3151 duration. For example, @code{--list-generations=20d} lists generations
3152 that are up to 20 days old.
3155 @item --delete-generations[=@var{pattern}]
3156 @itemx -d [@var{pattern}]
3157 When @var{pattern} is omitted, delete all generations except the current
3160 This command accepts the same patterns as @option{--list-generations}.
3161 When @var{pattern} is specified, delete the matching generations. When
3162 @var{pattern} specifies a duration, generations @emph{older} than the
3163 specified duration match. For instance, @code{--delete-generations=1m}
3164 deletes generations that are more than one month old.
3166 If the current generation matches, it is @emph{not} deleted. Also, the
3167 zeroth generation is never deleted.
3169 Note that deleting generations prevents rolling back to them.
3170 Consequently, this command must be used with care.
3174 Finally, since @command{guix package} may actually start build
3175 processes, it supports all the common build options (@pxref{Common Build
3176 Options}). It also supports package transformation options, such as
3177 @option{--with-source} (@pxref{Package Transformation Options}).
3178 However, note that package transformations are lost when upgrading; to
3179 preserve transformations across upgrades, you should define your own
3180 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3181 (@pxref{Defining Packages}).
3184 @section Substitutes
3187 @cindex pre-built binaries
3188 Guix supports transparent source/binary deployment, which means that it
3189 can either build things locally, or download pre-built items from a
3190 server, or both. We call these pre-built items @dfn{substitutes}---they
3191 are substitutes for local build results. In many cases, downloading a
3192 substitute is much faster than building things locally.
3194 Substitutes can be anything resulting from a derivation build
3195 (@pxref{Derivations}). Of course, in the common case, they are
3196 pre-built package binaries, but source tarballs, for instance, which
3197 also result from derivation builds, can be available as substitutes.
3200 * Official Substitute Server:: One particular source of substitutes.
3201 * Substitute Server Authorization:: How to enable or disable substitutes.
3202 * Substitute Authentication:: How Guix verifies substitutes.
3203 * Proxy Settings:: How to get substitutes via proxy.
3204 * Substitution Failure:: What happens when substitution fails.
3205 * On Trusting Binaries:: How can you trust that binary blob?
3208 @node Official Substitute Server
3209 @subsection Official Substitute Server
3212 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3213 that builds packages from Guix continuously for some
3214 architectures, and makes them available as substitutes. This is the
3215 default source of substitutes; it can be overridden by passing the
3216 @option{--substitute-urls} option either to @command{guix-daemon}
3217 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3218 or to client tools such as @command{guix package}
3219 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3222 Substitute URLs can be either HTTP or HTTPS.
3223 HTTPS is recommended because communications are encrypted; conversely,
3224 using HTTP makes all communications visible to an eavesdropper, who
3225 could use the information gathered to determine, for instance, whether
3226 your system has unpatched security vulnerabilities.
3228 Substitutes from the official build farm are enabled by default when
3229 using Guix System (@pxref{GNU Distribution}). However,
3230 they are disabled by default when using Guix on a foreign distribution,
3231 unless you have explicitly enabled them via one of the recommended
3232 installation steps (@pxref{Installation}). The following paragraphs
3233 describe how to enable or disable substitutes for the official build
3234 farm; the same procedure can also be used to enable substitutes for any
3235 other substitute server.
3237 @node Substitute Server Authorization
3238 @subsection Substitute Server Authorization
3241 @cindex substitutes, authorization thereof
3242 @cindex access control list (ACL), for substitutes
3243 @cindex ACL (access control list), for substitutes
3244 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3246 must add its public key to the access control list (ACL) of archive
3247 imports, using the @command{guix archive} command (@pxref{Invoking guix
3248 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3249 be compromised and to serve genuine substitutes.
3251 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3252 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3253 the installation prefix of Guix. If you installed Guix from source,
3254 make sure you checked the GPG signature of
3255 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3256 Then, you can run something like this:
3259 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3262 Once this is in place, the output of a command like @code{guix build}
3263 should change from something like:
3266 $ guix build emacs --dry-run
3267 The following derivations would be built:
3268 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3269 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3270 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3271 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3279 $ guix build emacs --dry-run
3280 112.3 MB would be downloaded:
3281 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3282 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3283 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3284 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3289 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3290 will be downloaded, when possible, for future builds.
3292 @cindex substitutes, how to disable
3293 The substitute mechanism can be disabled globally by running
3294 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3295 guix-daemon}). It can also be disabled temporarily by passing the
3296 @code{--no-substitutes} option to @command{guix package}, @command{guix
3297 build}, and other command-line tools.
3299 @node Substitute Authentication
3300 @subsection Substitute Authentication
3302 @cindex digital signatures
3303 Guix detects and raises an error when attempting to use a substitute
3304 that has been tampered with. Likewise, it ignores substitutes that are
3305 not signed, or that are not signed by one of the keys listed in the ACL.
3307 There is one exception though: if an unauthorized server provides
3308 substitutes that are @emph{bit-for-bit identical} to those provided by
3309 an authorized server, then the unauthorized server becomes eligible for
3310 downloads. For example, assume we have chosen two substitute servers
3314 --substitute-urls="https://a.example.org https://b.example.org"
3318 @cindex reproducible builds
3319 If the ACL contains only the key for @code{b.example.org}, and if
3320 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3321 then Guix will download substitutes from @code{a.example.org} because it
3322 comes first in the list and can be considered a mirror of
3323 @code{b.example.org}. In practice, independent build machines usually
3324 produce the same binaries, thanks to bit-reproducible builds (see
3327 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3328 (in other words, the server is not authenticated), contrary to what
3329 HTTPS clients such as Web browsers usually do. This is because Guix
3330 authenticates substitute information itself, as explained above, which
3331 is what we care about (whereas X.509 certificates are about
3332 authenticating bindings between domain names and public keys.)
3334 @node Proxy Settings
3335 @subsection Proxy Settings
3338 Substitutes are downloaded over HTTP or HTTPS.
3339 The @code{http_proxy} environment
3340 variable can be set in the environment of @command{guix-daemon} and is
3341 honored for downloads of substitutes. Note that the value of
3342 @code{http_proxy} in the environment where @command{guix build},
3343 @command{guix package}, and other client commands are run has
3344 @emph{absolutely no effect}.
3346 @node Substitution Failure
3347 @subsection Substitution Failure
3349 Even when a substitute for a derivation is available, sometimes the
3350 substitution attempt will fail. This can happen for a variety of
3351 reasons: the substitute server might be offline, the substitute may
3352 recently have been deleted, the connection might have been interrupted,
3355 When substitutes are enabled and a substitute for a derivation is
3356 available, but the substitution attempt fails, Guix will attempt to
3357 build the derivation locally depending on whether or not
3358 @code{--fallback} was given (@pxref{fallback-option,, common build
3359 option @code{--fallback}}). Specifically, if @code{--fallback} was
3360 omitted, then no local build will be performed, and the derivation is
3361 considered to have failed. However, if @code{--fallback} was given,
3362 then Guix will attempt to build the derivation locally, and the success
3363 or failure of the derivation depends on the success or failure of the
3364 local build. Note that when substitutes are disabled or no substitute
3365 is available for the derivation in question, a local build will
3366 @emph{always} be performed, regardless of whether or not
3367 @code{--fallback} was given.
3369 To get an idea of how many substitutes are available right now, you can
3370 try running the @command{guix weather} command (@pxref{Invoking guix
3371 weather}). This command provides statistics on the substitutes provided
3374 @node On Trusting Binaries
3375 @subsection On Trusting Binaries
3377 @cindex trust, of pre-built binaries
3378 Today, each individual's control over their own computing is at the
3379 mercy of institutions, corporations, and groups with enough power and
3380 determination to subvert the computing infrastructure and exploit its
3381 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3382 convenient, we encourage users to also build on their own, or even run
3383 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3384 interesting target. One way to help is by publishing the software you
3385 build using @command{guix publish} so that others have one more choice
3386 of server to download substitutes from (@pxref{Invoking guix publish}).
3388 Guix has the foundations to maximize build reproducibility
3389 (@pxref{Features}). In most cases, independent builds of a given
3390 package or derivation should yield bit-identical results. Thus, through
3391 a diverse set of independent package builds, we can strengthen the
3392 integrity of our systems. The @command{guix challenge} command aims to
3393 help users assess substitute servers, and to assist developers in
3394 finding out about non-deterministic package builds (@pxref{Invoking guix
3395 challenge}). Similarly, the @option{--check} option of @command{guix
3396 build} allows users to check whether previously-installed substitutes
3397 are genuine by rebuilding them locally (@pxref{build-check,
3398 @command{guix build --check}}).
3400 In the future, we want Guix to have support to publish and retrieve
3401 binaries to/from other users, in a peer-to-peer fashion. If you would
3402 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3404 @node Packages with Multiple Outputs
3405 @section Packages with Multiple Outputs
3407 @cindex multiple-output packages
3408 @cindex package outputs
3411 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3412 source package leads to exactly one directory in the store. When running
3413 @command{guix install glibc}, one installs the default output of the
3414 GNU libc package; the default output is called @code{out}, but its name
3415 can be omitted as shown in this command. In this particular case, the
3416 default output of @code{glibc} contains all the C header files, shared
3417 libraries, static libraries, Info documentation, and other supporting
3420 Sometimes it is more appropriate to separate the various types of files
3421 produced from a single source package into separate outputs. For
3422 instance, the GLib C library (used by GTK+ and related packages)
3423 installs more than 20 MiB of reference documentation as HTML pages.
3424 To save space for users who do not need it, the documentation goes to a
3425 separate output, called @code{doc}. To install the main GLib output,
3426 which contains everything but the documentation, one would run:
3432 @cindex documentation
3433 The command to install its documentation is:
3436 guix install glib:doc
3439 Some packages install programs with different ``dependency footprints''.
3440 For instance, the WordNet package installs both command-line tools and
3441 graphical user interfaces (GUIs). The former depend solely on the C
3442 library, whereas the latter depend on Tcl/Tk and the underlying X
3443 libraries. In this case, we leave the command-line tools in the default
3444 output, whereas the GUIs are in a separate output. This allows users
3445 who do not need the GUIs to save space. The @command{guix size} command
3446 can help find out about such situations (@pxref{Invoking guix size}).
3447 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3449 There are several such multiple-output packages in the GNU distribution.
3450 Other conventional output names include @code{lib} for libraries and
3451 possibly header files, @code{bin} for stand-alone programs, and
3452 @code{debug} for debugging information (@pxref{Installing Debugging
3453 Files}). The outputs of a packages are listed in the third column of
3454 the output of @command{guix package --list-available} (@pxref{Invoking
3458 @node Invoking guix gc
3459 @section Invoking @command{guix gc}
3461 @cindex garbage collector
3463 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3464 The @command{guix gc} command allows users to explicitly run the garbage
3465 collector to reclaim space from the @file{/gnu/store} directory. It is
3466 the @emph{only} way to remove files from @file{/gnu/store}---removing
3467 files or directories manually may break it beyond repair!
3470 @cindex garbage collector roots
3471 The garbage collector has a set of known @dfn{roots}: any file under
3472 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3473 cannot be deleted; any other file is considered @dfn{dead} and may be
3474 deleted. The set of garbage collector roots (``GC roots'' for short)
3475 includes default user profiles; by default, the symlinks under
3476 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3477 added with @command{guix build --root}, for example (@pxref{Invoking
3478 guix build}). The @command{guix gc --list-roots} command lists them.
3480 Prior to running @code{guix gc --collect-garbage} to make space, it is
3481 often useful to remove old generations from user profiles; that way, old
3482 package builds referenced by those generations can be reclaimed. This
3483 is achieved by running @code{guix package --delete-generations}
3484 (@pxref{Invoking guix package}).
3486 Our recommendation is to run a garbage collection periodically, or when
3487 you are short on disk space. For instance, to guarantee that at least
3488 5@tie{}GB are available on your disk, simply run:
3494 It is perfectly safe to run as a non-interactive periodic job
3495 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3496 Running @command{guix gc} with no arguments will collect as
3497 much garbage as it can, but that is often inconvenient: you may find
3498 yourself having to rebuild or re-download software that is ``dead'' from
3499 the GC viewpoint but that is necessary to build other pieces of
3500 software---e.g., the compiler tool chain.
3502 The @command{guix gc} command has three modes of operation: it can be
3503 used to garbage-collect any dead files (the default), to delete specific
3504 files (the @code{--delete} option), to print garbage-collector
3505 information, or for more advanced queries. The garbage collection
3506 options are as follows:
3509 @item --collect-garbage[=@var{min}]
3510 @itemx -C [@var{min}]
3511 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3512 sub-directories. This is the default operation when no option is
3515 When @var{min} is given, stop once @var{min} bytes have been collected.
3516 @var{min} may be a number of bytes, or it may include a unit as a
3517 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3518 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3520 When @var{min} is omitted, collect all the garbage.
3522 @item --free-space=@var{free}
3523 @itemx -F @var{free}
3524 Collect garbage until @var{free} space is available under
3525 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3526 as @code{500MiB}, as described above.
3528 When @var{free} or more is already available in @file{/gnu/store}, do
3529 nothing and exit immediately.
3531 @item --delete-generations[=@var{duration}]
3532 @itemx -d [@var{duration}]
3533 Before starting the garbage collection process, delete all the generations
3534 older than @var{duration}, for all the user profiles; when run as root, this
3535 applies to all the profiles @emph{of all the users}.
3537 For example, this command deletes all the generations of all your profiles
3538 that are older than 2 months (except generations that are current), and then
3539 proceeds to free space until at least 10 GiB are available:
3542 guix gc -d 2m -F 10G
3547 Attempt to delete all the store files and directories specified as
3548 arguments. This fails if some of the files are not in the store, or if
3549 they are still live.
3551 @item --list-failures
3552 List store items corresponding to cached build failures.
3554 This prints nothing unless the daemon was started with
3555 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3556 @option{--cache-failures}}).
3559 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3563 List store items in use by currently running processes. These store
3564 items are effectively considered GC roots: they cannot be deleted.
3566 @item --clear-failures
3567 Remove the specified store items from the failed-build cache.
3569 Again, this option only makes sense when the daemon is started with
3570 @option{--cache-failures}. Otherwise, it does nothing.
3573 Show the list of dead files and directories still present in the
3574 store---i.e., files and directories no longer reachable from any root.
3577 Show the list of live store files and directories.
3581 In addition, the references among existing store files can be queried:
3587 @cindex package dependencies
3588 List the references (respectively, the referrers) of store files given
3594 List the requisites of the store files passed as arguments. Requisites
3595 include the store files themselves, their references, and the references
3596 of these, recursively. In other words, the returned list is the
3597 @dfn{transitive closure} of the store files.
3599 @xref{Invoking guix size}, for a tool to profile the size of the closure
3600 of an element. @xref{Invoking guix graph}, for a tool to visualize
3601 the graph of references.
3605 Return the derivation(s) leading to the given store items
3606 (@pxref{Derivations}).
3608 For example, this command:
3611 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3615 returns the @file{.drv} file(s) leading to the @code{emacs} package
3616 installed in your profile.
3618 Note that there may be zero matching @file{.drv} files, for instance
3619 because these files have been garbage-collected. There can also be more
3620 than one matching @file{.drv} due to fixed-output derivations.
3623 Lastly, the following options allow you to check the integrity of the
3624 store and to control disk usage.
3628 @item --verify[=@var{options}]
3629 @cindex integrity, of the store
3630 @cindex integrity checking
3631 Verify the integrity of the store.
3633 By default, make sure that all the store items marked as valid in the
3634 database of the daemon actually exist in @file{/gnu/store}.
3636 When provided, @var{options} must be a comma-separated list containing one
3637 or more of @code{contents} and @code{repair}.
3639 When passing @option{--verify=contents}, the daemon computes the
3640 content hash of each store item and compares it against its hash in the
3641 database. Hash mismatches are reported as data corruptions. Because it
3642 traverses @emph{all the files in the store}, this command can take a
3643 long time, especially on systems with a slow disk drive.
3645 @cindex repairing the store
3646 @cindex corruption, recovering from
3647 Using @option{--verify=repair} or @option{--verify=contents,repair}
3648 causes the daemon to try to repair corrupt store items by fetching
3649 substitutes for them (@pxref{Substitutes}). Because repairing is not
3650 atomic, and thus potentially dangerous, it is available only to the
3651 system administrator. A lightweight alternative, when you know exactly
3652 which items in the store are corrupt, is @command{guix build --repair}
3653 (@pxref{Invoking guix build}).
3656 @cindex deduplication
3657 Optimize the store by hard-linking identical files---this is
3658 @dfn{deduplication}.
3660 The daemon performs deduplication after each successful build or archive
3661 import, unless it was started with @code{--disable-deduplication}
3662 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3663 this option is primarily useful when the daemon was running with
3664 @code{--disable-deduplication}.
3668 @node Invoking guix pull
3669 @section Invoking @command{guix pull}
3671 @cindex upgrading Guix
3672 @cindex updating Guix
3673 @cindex @command{guix pull}
3675 Packages are installed or upgraded to the latest version available in
3676 the distribution currently available on your local machine. To update
3677 that distribution, along with the Guix tools, you must run @command{guix
3678 pull}: the command downloads the latest Guix source code and package
3679 descriptions, and deploys it. Source code is downloaded from a
3680 @uref{https://git-scm.com, Git} repository, by default the official
3681 GNU@tie{}Guix repository, though this can be customized.
3683 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3684 (@pxref{Channels}) specified by one of the followings, in this order:
3688 the @option{--channels} option;
3690 the user's @file{~/.config/guix/channels.scm} file;
3692 the system-wide @file{/etc/guix/channels.scm} file;
3694 the built-in default channels specified in the @code{%default-channels}
3698 On completion, @command{guix package} will use packages and package
3699 versions from this just-retrieved copy of Guix. Not only that, but all
3700 the Guix commands and Scheme modules will also be taken from that latest
3701 version. New @command{guix} sub-commands added by the update also
3704 Any user can update their Guix copy using @command{guix pull}, and the
3705 effect is limited to the user who ran @command{guix pull}. For
3706 instance, when user @code{root} runs @command{guix pull}, this has no
3707 effect on the version of Guix that user @code{alice} sees, and vice
3710 The result of running @command{guix pull} is a @dfn{profile} available
3711 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3712 make sure to add it to the beginning of your search path so that you use
3713 the latest version, and similarly for the Info manual
3714 (@pxref{Documentation}):
3717 export PATH="$HOME/.config/guix/current/bin:$PATH"
3718 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3721 The @code{--list-generations} or @code{-l} option lists past generations
3722 produced by @command{guix pull}, along with details about their provenance:
3726 Generation 1 Jun 10 2018 00:18:18
3728 repository URL: https://git.savannah.gnu.org/git/guix.git
3729 branch: origin/master
3730 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3732 Generation 2 Jun 11 2018 11:02:49
3734 repository URL: https://git.savannah.gnu.org/git/guix.git
3735 branch: origin/master
3736 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3737 2 new packages: keepalived, libnfnetlink
3738 6 packages upgraded: emacs-nix-mode@@2.0.4,
3739 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3740 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3742 Generation 3 Jun 13 2018 23:31:07 (current)
3744 repository URL: https://git.savannah.gnu.org/git/guix.git
3745 branch: origin/master
3746 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3747 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3748 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3751 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3752 describe the current status of Guix.
3754 This @code{~/.config/guix/current} profile works exactly like the profiles
3755 created by @command{guix package} (@pxref{Invoking guix package}). That
3756 is, you can list generations, roll back to the previous
3757 generation---i.e., the previous Guix---and so on:
3760 $ guix pull --roll-back
3761 switched from generation 3 to 2
3762 $ guix pull --delete-generations=1
3763 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3766 You can also use @command{guix package} (@pxref{Invoking guix package})
3767 to manage the profile by naming it explicitly:
3769 $ guix package -p ~/.config/guix/current --roll-back
3770 switched from generation 3 to 2
3771 $ guix package -p ~/.config/guix/current --delete-generations=1
3772 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3775 The @command{guix pull} command is usually invoked with no arguments,
3776 but it supports the following options:
3779 @item --url=@var{url}
3780 @itemx --commit=@var{commit}
3781 @itemx --branch=@var{branch}
3782 Download code for the @code{guix} channel from the specified @var{url}, at the
3783 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3784 string), or @var{branch}.
3786 @cindex @file{channels.scm}, configuration file
3787 @cindex configuration file for channels
3788 These options are provided for convenience, but you can also specify your
3789 configuration in the @file{~/.config/guix/channels.scm} file or using the
3790 @option{--channels} option (see below).
3792 @item --channels=@var{file}
3793 @itemx -C @var{file}
3794 Read the list of channels from @var{file} instead of
3795 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3796 @var{file} must contain Scheme code that
3797 evaluates to a list of channel objects. @xref{Channels}, for more
3800 @cindex channel news
3803 Display the list of packages added or upgraded since the previous
3804 generation, as well as, occasionally, news written by channel authors
3805 for their users (@pxref{Channels, Writing Channel News}).
3807 The package information is the same as displayed upon @command{guix
3808 pull} completion, but without ellipses; it is also similar to the output
3809 of @command{guix pull -l} for the last generation (see below).
3811 @item --list-generations[=@var{pattern}]
3812 @itemx -l [@var{pattern}]
3813 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3814 is provided, the subset of generations that match @var{pattern}.
3815 The syntax of @var{pattern} is the same as with @code{guix package
3816 --list-generations} (@pxref{Invoking guix package}).
3819 @cindex rolling back
3820 @cindex undoing transactions
3821 @cindex transactions, undoing
3822 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3823 undo the last transaction.
3825 @item --switch-generation=@var{pattern}
3826 @itemx -S @var{pattern}
3828 Switch to a particular generation defined by @var{pattern}.
3830 @var{pattern} may be either a generation number or a number prefixed
3831 with ``+'' or ``-''. The latter means: move forward/backward by a
3832 specified number of generations. For example, if you want to return to
3833 the latest generation after @code{--roll-back}, use
3834 @code{--switch-generation=+1}.
3836 @item --delete-generations[=@var{pattern}]
3837 @itemx -d [@var{pattern}]
3838 When @var{pattern} is omitted, delete all generations except the current
3841 This command accepts the same patterns as @option{--list-generations}.
3842 When @var{pattern} is specified, delete the matching generations. When
3843 @var{pattern} specifies a duration, generations @emph{older} than the
3844 specified duration match. For instance, @code{--delete-generations=1m}
3845 deletes generations that are more than one month old.
3847 If the current generation matches, it is @emph{not} deleted.
3849 Note that deleting generations prevents rolling back to them.
3850 Consequently, this command must be used with care.
3852 @xref{Invoking guix describe}, for a way to display information about the
3853 current generation only.
3855 @item --profile=@var{profile}
3856 @itemx -p @var{profile}
3857 Use @var{profile} instead of @file{~/.config/guix/current}.
3861 Show which channel commit(s) would be used and what would be built or
3862 substituted but do not actually do it.
3864 @item --system=@var{system}
3865 @itemx -s @var{system}
3866 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3867 the system type of the build host.
3870 Produce verbose output, writing build logs to the standard error output.
3873 Use the bootstrap Guile to build the latest Guix. This option is only
3874 useful to Guix developers.
3877 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3878 repository and branch to pull from, as well as @emph{additional} repositories
3879 containing package modules that should be deployed. @xref{Channels}, for more
3882 In addition, @command{guix pull} supports all the common build options
3883 (@pxref{Common Build Options}).
3889 @cindex @file{channels.scm}, configuration file
3890 @cindex configuration file for channels
3891 @cindex @command{guix pull}, configuration file
3892 @cindex configuration of @command{guix pull}
3893 Guix and its package collection are updated by running @command{guix pull}
3894 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3895 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3896 customized by defining @dfn{channels} in the
3897 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3898 of a Git repository to be deployed, and @command{guix pull} can be instructed
3899 to pull from one or more channels. In other words, channels can be used to
3900 @emph{customize} and to @emph{extend} Guix, as we will see below.
3902 @subsection Using a Custom Guix Channel
3904 The channel called @code{guix} specifies where Guix itself---its command-line
3905 tools as well as its package collection---should be downloaded. For instance,
3906 suppose you want to update from your own copy of the Guix repository at
3907 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3908 write in @code{~/.config/guix/channels.scm} this specification:
3911 ;; Tell 'guix pull' to use my own repo.
3914 (url "https://example.org/my-guix.git")
3915 (branch "super-hacks")))
3919 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3920 branch of the repository at @code{example.org}.
3922 @subsection Specifying Additional Channels
3924 @cindex extending the package collection (channels)
3925 @cindex personal packages (channels)
3926 @cindex channels, for personal packages
3927 You can also specify @emph{additional channels} to pull from. Let's say you
3928 have a bunch of custom package variants or personal packages that you think
3929 would make little sense to contribute to the Guix project, but would like to
3930 have these packages transparently available to you at the command line. You
3931 would first write modules containing those package definitions (@pxref{Package
3932 Modules}), maintain them in a Git repository, and then you and anyone else can
3933 use it as an additional channel to get packages from. Neat, no?
3935 @c What follows stems from discussions at
3936 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3937 @c earlier discussions on guix-devel@gnu.org.
3939 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3940 publish your personal channel to the world, we would like to share a few words
3945 Before publishing a channel, please consider contributing your package
3946 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3947 to free software of all sorts, and packages in Guix proper are readily
3948 available to all Guix users and benefit from the project's quality assurance
3952 When you maintain package definitions outside Guix, we, Guix developers,
3953 consider that @emph{the compatibility burden is on you}. Remember that
3954 package modules and package definitions are just Scheme code that uses various
3955 programming interfaces (APIs). We want to remain free to change these APIs to
3956 keep improving Guix, possibly in ways that break your channel. We never
3957 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3961 Corollary: if you're using an external channel and that channel breaks, please
3962 @emph{report the issue to the channel authors}, not to the Guix project.
3965 You've been warned! Having said this, we believe external channels are a
3966 practical way to exert your freedom to augment Guix' package collection and to
3967 share your improvements, which are basic tenets of
3968 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3969 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3972 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3973 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3976 @vindex %default-channels
3978 ;; Add my personal packages to those Guix provides.
3980 (name 'my-personal-packages)
3981 (url "https://example.org/personal-packages.git"))
3986 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3987 add a channel the list of channels that the variable @code{%default-channels}
3988 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3989 Manual}). With this file in place, @command{guix pull} builds not only Guix
3990 but also the package modules from your own repository. The result in
3991 @file{~/.config/guix/current} is the union of Guix with your own package
3995 $ guix pull --list-generations
3997 Generation 19 Aug 27 2018 16:20:48
3999 repository URL: https://git.savannah.gnu.org/git/guix.git
4001 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4002 my-personal-packages dd3df5e
4003 repository URL: https://example.org/personal-packages.git
4005 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4006 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4007 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4011 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4012 both Guix and packages from the @code{my-personal-packages} channel. Among
4013 the new and upgraded packages that are listed, some like @code{my-gimp} and
4014 @code{my-emacs-with-cool-features} might come from
4015 @code{my-personal-packages}, while others come from the Guix default channel.
4017 To create a channel, create a Git repository containing your own package
4018 modules and make it available. The repository can contain anything, but a
4019 useful channel will contain Guile modules that export packages. Once you
4020 start using a channel, Guix will behave as if the root directory of that
4021 channel's Git repository has been added to the Guile load path (@pxref{Load
4022 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4023 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4024 module, then the module will be available under the name @code{(my-packages
4025 my-tools)}, and you will be able to use it like any other module
4026 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4028 @cindex dependencies, channels
4029 @cindex meta-data, channels
4030 @subsection Declaring Channel Dependencies
4032 Channel authors may decide to augment a package collection provided by other
4033 channels. They can declare their channel to be dependent on other channels in
4034 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4035 the channel repository.
4037 The meta-data file should contain a simple S-expression like this:
4044 (name some-collection)
4045 (url "https://example.org/first-collection.git"))
4047 (name some-other-collection)
4048 (url "https://example.org/second-collection.git")
4049 (branch "testing"))))
4052 In the above example this channel is declared to depend on two other channels,
4053 which will both be fetched automatically. The modules provided by the channel
4054 will be compiled in an environment where the modules of all these declared
4055 channels are available.
4057 For the sake of reliability and maintainability, you should avoid dependencies
4058 on channels that you don't control, and you should aim to keep the number of
4059 dependencies to a minimum.
4061 @cindex subdirectory, channels
4062 @subsection Package Modules in a Sub-directory
4064 As a channel author, you may want to keep your channel modules in a
4065 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4066 add a meta-data file @file{.guix-channel} that contains:
4074 @cindex news, for channels
4075 @subsection Writing Channel News
4077 Channel authors may occasionally want to communicate to their users
4078 information about important changes in the channel. You'd send them all
4079 an email, but that's not convenient.
4081 Instead, channels can provide a @dfn{news file}; when the channel users
4082 run @command{guix pull}, that news file is automatically read and
4083 @command{guix pull --news} can display the announcements that correspond
4084 to the new commits that have been pulled, if any.
4086 To do that, channel authors must first declare the name of the news file
4087 in their @file{.guix-channel} file:
4092 (news-file "etc/news.txt"))
4095 The news file itself, @file{etc/news.txt} in this example, must look
4096 something like this:
4101 (entry (tag "the-bug-fix")
4102 (title (en "Fixed terrible bug")
4104 (body (en "@@emph@{Good news@}! It's fixed!")
4105 (eo "Certe ĝi pli bone funkcias nun!")))
4106 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4107 (title (en "Added a great package")
4108 (ca "Què vol dir guix?"))
4109 (body (en "Don't miss the @@code@{hello@} package!"))))
4112 The file consists of a list of @dfn{news entries}. Each entry is
4113 associated with a commit or tag: it describes changes made in this
4114 commit, possibly in preceding commits as well. Users see entries only
4115 the first time they obtain the commit the entry refers to.
4117 The @code{title} field should be a one-line summary while @code{body}
4118 can be arbitrarily long, and both can contain Texinfo markup
4119 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4120 a list of language tag/message tuples, which allows @command{guix pull}
4121 to display news in the language that corresponds to the user's locale.
4123 If you want to translate news using a gettext-based workflow, you can
4124 extract translatable strings with @command{xgettext} (@pxref{xgettext
4125 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4126 you write news entries in English first, the command below creates a PO
4127 file containing the strings to translate:
4130 xgettext -o news.po -l scheme -ken etc/news.scm
4133 To sum up, yes, you could use your channel as a blog. But beware, this
4134 is @emph{not quite} what your users might expect.
4136 @subsection Replicating Guix
4138 @cindex pinning, channels
4139 @cindex replicating Guix
4140 @cindex reproducibility, of Guix
4141 The @command{guix pull --list-generations} output above shows precisely which
4142 commits were used to build this instance of Guix. We can thus replicate it,
4143 say, on another machine, by providing a channel specification in
4144 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4147 ;; Deploy specific commits of my channels of interest.
4150 (url "https://git.savannah.gnu.org/git/guix.git")
4151 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4153 (name 'my-personal-packages)
4154 (url "https://example.org/personal-packages.git")
4155 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4158 The @command{guix describe --format=channels} command can even generate this
4159 list of channels directly (@pxref{Invoking guix describe}). The resulting
4160 file can be used with the -C options of @command{guix pull}
4161 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4162 (@pxref{Invoking guix time-machine}).
4164 At this point the two machines run the @emph{exact same Guix}, with access to
4165 the @emph{exact same packages}. The output of @command{guix build gimp} on
4166 one machine will be exactly the same, bit for bit, as the output of the same
4167 command on the other machine. It also means both machines have access to all
4168 the source code of Guix and, transitively, to all the source code of every
4171 This gives you super powers, allowing you to track the provenance of binary
4172 artifacts with very fine grain, and to reproduce software environments at
4173 will---some sort of ``meta reproducibility'' capabilities, if you will.
4174 @xref{Inferiors}, for another way to take advantage of these super powers.
4176 @node Invoking guix time-machine
4177 @section Invoking @command{guix time-machine}
4179 @cindex @command{guix time-machine}
4180 @cindex pinning, channels
4181 @cindex replicating Guix
4182 @cindex reproducibility, of Guix
4184 The @command{guix time-machine} command provides access to other
4185 revisions of Guix, for example to install older versions of packages,
4186 or to reproduce a computation in an identical environment. The revision
4187 of Guix to be used is defined by a commit or by a channel
4188 description file created by @command{guix describe}
4189 (@pxref{Invoking guix describe}).
4191 The general syntax is:
4194 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4197 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4198 @command{guix} command if the specified revision. The @var{options} that define
4199 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4202 @item --url=@var{url}
4203 @itemx --commit=@var{commit}
4204 @itemx --branch=@var{branch}
4205 Use the @code{guix} channel from the specified @var{url}, at the
4206 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4207 string), or @var{branch}.
4209 @item --channels=@var{file}
4210 @itemx -C @var{file}
4211 Read the list of channels from @var{file}. @var{file} must contain
4212 Scheme code that evaluates to a list of channel objects.
4213 @xref{Channels} for more information.
4216 As for @command{guix pull}, the absence of any options means that the
4217 the latest commit on the master branch will be used. The command
4220 guix time-machine -- build hello
4223 will thus build the package @code{hello} as defined in the master branch,
4224 which is in general a newer revison of Guix than you have installed.
4225 Time travel works in both directions!
4227 Note that @command{guix time-machine} can trigger builds of channels and
4228 their dependencies, and these are controlled by the standard build
4229 options (@pxref{Common Build Options}).
4234 @c TODO: Remove this once we're more confident about API stability.
4236 The functionality described here is a ``technology preview'' as of version
4237 @value{VERSION}. As such, the interface is subject to change.
4241 @cindex composition of Guix revisions
4242 Sometimes you might need to mix packages from the revision of Guix you're
4243 currently running with packages available in a different revision of Guix.
4244 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4245 revisions in arbitrary ways.
4247 @cindex inferior packages
4248 Technically, an ``inferior'' is essentially a separate Guix process connected
4249 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4250 @code{(guix inferior)} module allows you to create inferiors and to
4251 communicate with them. It also provides a high-level interface to browse and
4252 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4254 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4255 to interact with a separate revision of Guix. For example, let's assume you
4256 want to install in your profile the current @code{guile} package, along with
4257 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4258 because the newer @code{guile-json} has an incompatible API and you want to
4259 run your code against the old API@. To do that, you could write a manifest for
4260 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4261 manifest, you would create an inferior for that old Guix revision you care
4262 about, and you would look up the @code{guile-json} package in the inferior:
4265 (use-modules (guix inferior) (guix channels)
4266 (srfi srfi-1)) ;for 'first'
4269 ;; This is the old revision from which we want to
4270 ;; extract guile-json.
4273 (url "https://git.savannah.gnu.org/git/guix.git")
4275 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4278 ;; An inferior representing the above revision.
4279 (inferior-for-channels channels))
4281 ;; Now create a manifest with the current "guile" package
4282 ;; and the old "guile-json" package.
4284 (list (first (lookup-inferior-packages inferior "guile-json"))
4285 (specification->package "guile")))
4288 On its first run, @command{guix package --manifest} might have to build the
4289 channel you specified before it can create the inferior; subsequent runs will
4290 be much faster because the Guix revision will be cached.
4292 The @code{(guix inferior)} module provides the following procedures to open an
4295 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4296 [#:cache-directory] [#:ttl]
4297 Return an inferior for @var{channels}, a list of channels. Use the cache at
4298 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4299 This procedure opens a new connection to the build daemon.
4301 As a side effect, this procedure may build or substitute binaries for
4302 @var{channels}, which can take time.
4305 @deffn {Scheme Procedure} open-inferior @var{directory} @
4306 [#:command "bin/guix"]
4307 Open the inferior Guix in @var{directory}, running
4308 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4309 the inferior could not be launched.
4312 @cindex inferior packages
4313 The procedures listed below allow you to obtain and manipulate inferior
4316 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4317 Return the list of packages known to @var{inferior}.
4320 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4322 Return the sorted list of inferior packages matching @var{name} in
4323 @var{inferior}, with highest version numbers first. If @var{version} is true,
4324 return only packages with a version number prefixed by @var{version}.
4327 @deffn {Scheme Procedure} inferior-package? @var{obj}
4328 Return true if @var{obj} is an inferior package.
4331 @deffn {Scheme Procedure} inferior-package-name @var{package}
4332 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4333 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4334 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4335 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4336 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4337 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4338 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4339 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4340 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4341 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4342 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4343 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4344 These procedures are the counterpart of package record accessors
4345 (@pxref{package Reference}). Most of them work by querying the inferior
4346 @var{package} comes from, so the inferior must still be live when you call
4350 Inferior packages can be used transparently like any other package or
4351 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4352 transparently handled by the @code{packages->manifest} procedure, which is
4353 commonly use in manifests (@pxref{Invoking guix package, the
4354 @option{--manifest} option of @command{guix package}}). Thus you can insert
4355 an inferior package pretty much anywhere you would insert a regular package:
4356 in manifests, in the @code{packages} field of your @code{operating-system}
4357 declaration, and so on.
4359 @node Invoking guix describe
4360 @section Invoking @command{guix describe}
4362 @cindex reproducibility
4363 @cindex replicating Guix
4364 Often you may want to answer questions like: ``Which revision of Guix am I
4365 using?'' or ``Which channels am I using?'' This is useful information in many
4366 situations: if you want to @emph{replicate} an environment on a different
4367 machine or user account, if you want to report a bug or to determine what
4368 change in the channels you are using caused it, or if you want to record your
4369 system state for reproducibility purposes. The @command{guix describe}
4370 command answers these questions.
4372 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4373 displays the channel(s) that it was built from, including their repository URL
4374 and commit IDs (@pxref{Channels}):
4378 Generation 10 Sep 03 2018 17:32:44 (current)
4380 repository URL: https://git.savannah.gnu.org/git/guix.git
4382 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4385 If you're familiar with the Git version control system, this is similar in
4386 spirit to @command{git describe}; the output is also similar to that of
4387 @command{guix pull --list-generations}, but limited to the current generation
4388 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4389 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4390 information is all it takes to describe the revision of Guix you're using, and
4391 also to replicate it.
4393 To make it easier to replicate Guix, @command{guix describe} can also be asked
4394 to return a list of channels instead of the human-readable description above:
4397 $ guix describe -f channels
4400 (url "https://git.savannah.gnu.org/git/guix.git")
4402 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4406 You can save this to a file and feed it to @command{guix pull -C} on some
4407 other machine or at a later point in time, which will instantiate @emph{this
4408 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4409 From there on, since you're able to deploy the same revision of Guix, you can
4410 just as well @emph{replicate a complete software environment}. We humbly
4411 think that this is @emph{awesome}, and we hope you'll like it too!
4413 The details of the options supported by @command{guix describe} are as
4417 @item --format=@var{format}
4418 @itemx -f @var{format}
4419 Produce output in the specified @var{format}, one of:
4423 produce human-readable output;
4425 produce a list of channel specifications that can be passed to @command{guix
4426 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4430 produce a list of channel specifications in JSON format;
4432 produce a list of channel specifications in Recutils format.
4435 @item --profile=@var{profile}
4436 @itemx -p @var{profile}
4437 Display information about @var{profile}.
4440 @node Invoking guix archive
4441 @section Invoking @command{guix archive}
4443 @cindex @command{guix archive}
4445 The @command{guix archive} command allows users to @dfn{export} files
4446 from the store into a single archive, and to later @dfn{import} them on
4447 a machine that runs Guix.
4448 In particular, it allows store files to be transferred from one machine
4449 to the store on another machine.
4452 If you're looking for a way to produce archives in a format suitable for
4453 tools other than Guix, @pxref{Invoking guix pack}.
4456 @cindex exporting store items
4457 To export store files as an archive to standard output, run:
4460 guix archive --export @var{options} @var{specifications}...
4463 @var{specifications} may be either store file names or package
4464 specifications, as for @command{guix package} (@pxref{Invoking guix
4465 package}). For instance, the following command creates an archive
4466 containing the @code{gui} output of the @code{git} package and the main
4467 output of @code{emacs}:
4470 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4473 If the specified packages are not built yet, @command{guix archive}
4474 automatically builds them. The build process may be controlled with the
4475 common build options (@pxref{Common Build Options}).
4477 To transfer the @code{emacs} package to a machine connected over SSH,
4481 guix archive --export -r emacs | ssh the-machine guix archive --import
4485 Similarly, a complete user profile may be transferred from one machine
4486 to another like this:
4489 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4490 ssh the-machine guix archive --import
4494 However, note that, in both examples, all of @code{emacs} and the
4495 profile as well as all of their dependencies are transferred (due to
4496 @code{-r}), regardless of what is already available in the store on the
4497 target machine. The @code{--missing} option can help figure out which
4498 items are missing from the target store. The @command{guix copy}
4499 command simplifies and optimizes this whole process, so this is probably
4500 what you should use in this case (@pxref{Invoking guix copy}).
4502 @cindex nar, archive format
4503 @cindex normalized archive (nar)
4504 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4505 comparable in spirit to `tar', but with differences
4506 that make it more appropriate for our purposes. First, rather than
4507 recording all Unix metadata for each file, the nar format only mentions
4508 the file type (regular, directory, or symbolic link); Unix permissions
4509 and owner/group are dismissed. Second, the order in which directory
4510 entries are stored always follows the order of file names according to
4511 the C locale collation order. This makes archive production fully
4514 When exporting, the daemon digitally signs the contents of the archive,
4515 and that digital signature is appended. When importing, the daemon
4516 verifies the signature and rejects the import in case of an invalid
4517 signature or if the signing key is not authorized.
4518 @c FIXME: Add xref to daemon doc about signatures.
4520 The main options are:
4524 Export the specified store files or packages (see below.) Write the
4525 resulting archive to the standard output.
4527 Dependencies are @emph{not} included in the output, unless
4528 @code{--recursive} is passed.
4532 When combined with @code{--export}, this instructs @command{guix
4533 archive} to include dependencies of the given items in the archive.
4534 Thus, the resulting archive is self-contained: it contains the closure
4535 of the exported store items.
4538 Read an archive from the standard input, and import the files listed
4539 therein into the store. Abort if the archive has an invalid digital
4540 signature, or if it is signed by a public key not among the authorized
4541 keys (see @code{--authorize} below.)
4544 Read a list of store file names from the standard input, one per line,
4545 and write on the standard output the subset of these files missing from
4548 @item --generate-key[=@var{parameters}]
4549 @cindex signing, archives
4550 Generate a new key pair for the daemon. This is a prerequisite before
4551 archives can be exported with @code{--export}. Note that this operation
4552 usually takes time, because it needs to gather enough entropy to
4553 generate the key pair.
4555 The generated key pair is typically stored under @file{/etc/guix}, in
4556 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4557 key, which must be kept secret.) When @var{parameters} is omitted,
4558 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4559 versions before 1.6.0, it is a 4096-bit RSA key.
4560 Alternatively, @var{parameters} can specify
4561 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4562 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4563 Libgcrypt Reference Manual}).
4566 @cindex authorizing, archives
4567 Authorize imports signed by the public key passed on standard input.
4568 The public key must be in ``s-expression advanced format''---i.e., the
4569 same format as the @file{signing-key.pub} file.
4571 The list of authorized keys is kept in the human-editable file
4572 @file{/etc/guix/acl}. The file contains
4573 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4574 s-expressions''} and is structured as an access-control list in the
4575 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4578 @item --extract=@var{directory}
4579 @itemx -x @var{directory}
4580 Read a single-item archive as served by substitute servers
4581 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4582 low-level operation needed in only very narrow use cases; see below.
4584 For example, the following command extracts the substitute for Emacs
4585 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4589 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4590 | bunzip2 | guix archive -x /tmp/emacs
4593 Single-item archives are different from multiple-item archives produced
4594 by @command{guix archive --export}; they contain a single store item,
4595 and they do @emph{not} embed a signature. Thus this operation does
4596 @emph{no} signature verification and its output should be considered
4599 The primary purpose of this operation is to facilitate inspection of
4600 archive contents coming from possibly untrusted substitute servers.
4604 Read a single-item archive as served by substitute servers
4605 (@pxref{Substitutes}) and print the list of files it contains, as in
4610 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4611 | lzip -d | guix archive -t
4617 @c *********************************************************************
4619 @chapter Development
4621 @cindex software development
4622 If you are a software developer, Guix provides tools that you should find
4623 helpful---independently of the language you're developing in. This is what
4624 this chapter is about.
4626 The @command{guix environment} command provides a convenient way to set up
4627 @dfn{development environments} containing all the dependencies and tools
4628 necessary to work on the software package of your choice. The @command{guix
4629 pack} command allows you to create @dfn{application bundles} that can be
4630 easily distributed to users who do not run Guix.
4633 * Invoking guix environment:: Setting up development environments.
4634 * Invoking guix pack:: Creating software bundles.
4637 @node Invoking guix environment
4638 @section Invoking @command{guix environment}
4640 @cindex reproducible build environments
4641 @cindex development environments
4642 @cindex @command{guix environment}
4643 @cindex environment, package build environment
4644 The purpose of @command{guix environment} is to assist hackers in
4645 creating reproducible development environments without polluting their
4646 package profile. The @command{guix environment} tool takes one or more
4647 packages, builds all of their inputs, and creates a shell
4648 environment to use them.
4650 The general syntax is:
4653 guix environment @var{options} @var{package}@dots{}
4656 The following example spawns a new shell set up for the development of
4660 guix environment guile
4663 If the needed dependencies are not built yet, @command{guix environment}
4664 automatically builds them. The environment of the new shell is an augmented
4665 version of the environment that @command{guix environment} was run in.
4666 It contains the necessary search paths for building the given package
4667 added to the existing environment variables. To create a ``pure''
4668 environment, in which the original environment variables have been unset,
4669 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4670 environment variables such as @code{PATH} in their @file{~/.bashrc}
4671 file. As a consequence, when @code{guix environment} launches it, Bash
4672 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4673 environment variables. It is an error to define such environment
4674 variables in @file{.bashrc}; instead, they should be defined in
4675 @file{.bash_profile}, which is sourced only by log-in shells.
4676 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4677 details on Bash start-up files.}.
4679 @vindex GUIX_ENVIRONMENT
4680 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4681 variable in the shell it spawns; its value is the file name of the
4682 profile of this environment. This allows users to, say, define a
4683 specific prompt for development environments in their @file{.bashrc}
4684 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4687 if [ -n "$GUIX_ENVIRONMENT" ]
4689 export PS1="\u@@\h \w [dev]\$ "
4694 ...@: or to browse the profile:
4697 $ ls "$GUIX_ENVIRONMENT/bin"
4700 Additionally, more than one package may be specified, in which case the
4701 union of the inputs for the given packages are used. For example, the
4702 command below spawns a shell where all of the dependencies of both Guile
4703 and Emacs are available:
4706 guix environment guile emacs
4709 Sometimes an interactive shell session is not desired. An arbitrary
4710 command may be invoked by placing the @code{--} token to separate the
4711 command from the rest of the arguments:
4714 guix environment guile -- make -j4
4717 In other situations, it is more convenient to specify the list of
4718 packages needed in the environment. For example, the following command
4719 runs @command{python} from an environment containing Python@tie{}2.7 and
4723 guix environment --ad-hoc python2-numpy python-2.7 -- python
4726 Furthermore, one might want the dependencies of a package and also some
4727 additional packages that are not build-time or runtime dependencies, but
4728 are useful when developing nonetheless. Because of this, the
4729 @code{--ad-hoc} flag is positional. Packages appearing before
4730 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4731 added to the environment. Packages appearing after are interpreted as
4732 packages that will be added to the environment directly. For example,
4733 the following command creates a Guix development environment that
4734 additionally includes Git and strace:
4737 guix environment guix --ad-hoc git strace
4740 Sometimes it is desirable to isolate the environment as much as
4741 possible, for maximal purity and reproducibility. In particular, when
4742 using Guix on a host distro that is not Guix System, it is desirable to
4743 prevent access to @file{/usr/bin} and other system-wide resources from
4744 the development environment. For example, the following command spawns
4745 a Guile REPL in a ``container'' where only the store and the current
4746 working directory are mounted:
4749 guix environment --ad-hoc --container guile -- guile
4753 The @code{--container} option requires Linux-libre 3.19 or newer.
4756 The available options are summarized below.
4759 @item --root=@var{file}
4760 @itemx -r @var{file}
4761 @cindex persistent environment
4762 @cindex garbage collector root, for environments
4763 Make @var{file} a symlink to the profile for this environment, and
4764 register it as a garbage collector root.
4766 This is useful if you want to protect your environment from garbage
4767 collection, to make it ``persistent''.
4769 When this option is omitted, the environment is protected from garbage
4770 collection only for the duration of the @command{guix environment}
4771 session. This means that next time you recreate the same environment,
4772 you could have to rebuild or re-download packages. @xref{Invoking guix
4773 gc}, for more on GC roots.
4775 @item --expression=@var{expr}
4776 @itemx -e @var{expr}
4777 Create an environment for the package or list of packages that
4778 @var{expr} evaluates to.
4780 For example, running:
4783 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4786 starts a shell with the environment for this specific variant of the
4792 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4795 starts a shell with all the base system packages available.
4797 The above commands only use the default output of the given packages.
4798 To select other outputs, two element tuples can be specified:
4801 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4804 @item --load=@var{file}
4805 @itemx -l @var{file}
4806 Create an environment for the package or list of packages that the code
4807 within @var{file} evaluates to.
4809 As an example, @var{file} might contain a definition like this
4810 (@pxref{Defining Packages}):
4813 @verbatiminclude environment-gdb.scm
4816 @item --manifest=@var{file}
4817 @itemx -m @var{file}
4818 Create an environment for the packages contained in the manifest object
4819 returned by the Scheme code in @var{file}. This option can be repeated
4820 several times, in which case the manifests are concatenated.
4822 This is similar to the same-named option in @command{guix package}
4823 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4827 Include all specified packages in the resulting environment, as if an
4828 @i{ad hoc} package were defined with them as inputs. This option is
4829 useful for quickly creating an environment without having to write a
4830 package expression to contain the desired inputs.
4832 For instance, the command:
4835 guix environment --ad-hoc guile guile-sdl -- guile
4838 runs @command{guile} in an environment where Guile and Guile-SDL are
4841 Note that this example implicitly asks for the default output of
4842 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4843 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4844 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4846 This option may be composed with the default behavior of @command{guix
4847 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4848 as packages whose dependencies will be added to the environment, the
4849 default behavior. Packages appearing after are interpreted as packages
4850 that will be added to the environment directly.
4853 Unset existing environment variables when building the new environment, except
4854 those specified with @option{--preserve} (see below.) This has the effect of
4855 creating an environment in which search paths only contain package inputs.
4857 @item --preserve=@var{regexp}
4858 @itemx -E @var{regexp}
4859 When used alongside @option{--pure}, preserve the environment variables
4860 matching @var{regexp}---in other words, put them on a ``white list'' of
4861 environment variables that must be preserved. This option can be repeated
4865 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4869 This example runs @command{mpirun} in a context where the only environment
4870 variables defined are @code{PATH}, environment variables whose name starts
4871 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4874 @item --search-paths
4875 Display the environment variable definitions that make up the
4878 @item --system=@var{system}
4879 @itemx -s @var{system}
4880 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4885 Run @var{command} within an isolated container. The current working
4886 directory outside the container is mapped inside the container.
4887 Additionally, unless overridden with @code{--user}, a dummy home
4888 directory is created that matches the current user's home directory, and
4889 @file{/etc/passwd} is configured accordingly.
4891 The spawned process runs as the current user outside the container. Inside
4892 the container, it has the same UID and GID as the current user, unless
4893 @option{--user} is passed (see below.)
4897 For containers, share the network namespace with the host system.
4898 Containers created without this flag only have access to the loopback
4901 @item --link-profile
4903 For containers, link the environment profile to
4904 @file{~/.guix-profile} within the container. This is equivalent to
4905 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4906 within the container. Linking will fail and abort the environment if
4907 the directory already exists, which will certainly be the case if
4908 @command{guix environment} was invoked in the user's home directory.
4910 Certain packages are configured to look in
4911 @code{~/.guix-profile} for configuration files and data;@footnote{For
4912 example, the @code{fontconfig} package inspects
4913 @file{~/.guix-profile/share/fonts} for additional fonts.}
4914 @code{--link-profile} allows these programs to behave as expected within
4917 @item --user=@var{user}
4918 @itemx -u @var{user}
4919 For containers, use the username @var{user} in place of the current
4920 user. The generated @file{/etc/passwd} entry within the container will
4921 contain the name @var{user}, the home directory will be
4922 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4923 the UID and GID inside the container are 1000. @var{user}
4924 need not exist on the system.
4926 Additionally, any shared or exposed path (see @code{--share} and
4927 @code{--expose} respectively) whose target is within the current user's
4928 home directory will be remapped relative to @file{/home/USER}; this
4929 includes the automatic mapping of the current working directory.
4932 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4934 guix environment --container --user=foo \
4935 --expose=$HOME/test \
4936 --expose=/tmp/target=$HOME/target
4939 While this will limit the leaking of user identity through home paths
4940 and each of the user fields, this is only one useful component of a
4941 broader privacy/anonymity solution---not one in and of itself.
4944 For containers, the default behavior is to share the current working
4945 directory with the isolated container and immediately change to that
4946 directory within the container. If this is undesirable, @code{--no-cwd}
4947 will cause the current working directory to @emph{not} be automatically
4948 shared and will change to the user's home directory within the container
4949 instead. See also @code{--user}.
4951 @item --expose=@var{source}[=@var{target}]
4952 For containers, expose the file system @var{source} from the host system
4953 as the read-only file system @var{target} within the container. If
4954 @var{target} is not specified, @var{source} is used as the target mount
4955 point in the container.
4957 The example below spawns a Guile REPL in a container in which the user's
4958 home directory is accessible read-only via the @file{/exchange}
4962 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4965 @item --share=@var{source}[=@var{target}]
4966 For containers, share the file system @var{source} from the host system
4967 as the writable file system @var{target} within the container. If
4968 @var{target} is not specified, @var{source} is used as the target mount
4969 point in the container.
4971 The example below spawns a Guile REPL in a container in which the user's
4972 home directory is accessible for both reading and writing via the
4973 @file{/exchange} directory:
4976 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4980 @command{guix environment}
4981 also supports all of the common build options that @command{guix
4982 build} supports (@pxref{Common Build Options}) as well as package
4983 transformation options (@pxref{Package Transformation Options}).
4985 @node Invoking guix pack
4986 @section Invoking @command{guix pack}
4988 Occasionally you want to pass software to people who are not (yet!)
4989 lucky enough to be using Guix. You'd tell them to run @command{guix
4990 package -i @var{something}}, but that's not possible in this case. This
4991 is where @command{guix pack} comes in.
4994 If you are looking for ways to exchange binaries among machines that
4995 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4996 publish}, and @ref{Invoking guix archive}.
5001 @cindex application bundle
5002 @cindex software bundle
5003 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5004 @dfn{software bundle}: it creates a tarball or some other archive
5005 containing the binaries of the software you're interested in, and all
5006 its dependencies. The resulting archive can be used on any machine that
5007 does not have Guix, and people can run the exact same binaries as those
5008 you have with Guix. The pack itself is created in a bit-reproducible
5009 fashion, so anyone can verify that it really contains the build results
5010 that you pretend to be shipping.
5012 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5013 their dependencies, you can run:
5016 $ guix pack guile emacs geiser
5018 /gnu/store/@dots{}-pack.tar.gz
5021 The result here is a tarball containing a @file{/gnu/store} directory
5022 with all the relevant packages. The resulting tarball contains a
5023 @dfn{profile} with the three packages of interest; the profile is the
5024 same as would be created by @command{guix package -i}. It is this
5025 mechanism that is used to create Guix's own standalone binary tarball
5026 (@pxref{Binary Installation}).
5028 Users of this pack would have to run
5029 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5030 find inconvenient. To work around it, you can create, say, a
5031 @file{/opt/gnu/bin} symlink to the profile:
5034 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5038 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5040 @cindex relocatable binaries, with @command{guix pack}
5041 What if the recipient of your pack does not have root privileges on
5042 their machine, and thus cannot unpack it in the root file system? In
5043 that case, you will want to use the @code{--relocatable} option (see
5044 below). This option produces @dfn{relocatable binaries}, meaning they
5045 they can be placed anywhere in the file system hierarchy: in the example
5046 above, users can unpack your tarball in their home directory and
5047 directly run @file{./opt/gnu/bin/guile}.
5049 @cindex Docker, build an image with guix pack
5050 Alternatively, you can produce a pack in the Docker image format using
5051 the following command:
5054 guix pack -f docker guile emacs geiser
5058 The result is a tarball that can be passed to the @command{docker load}
5060 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5061 documentation} for more information.
5063 @cindex Singularity, build an image with guix pack
5064 @cindex SquashFS, build an image with guix pack
5065 Yet another option is to produce a SquashFS image with the following
5069 guix pack -f squashfs bash guile emacs geiser
5073 The result is a SquashFS file system image that can either be mounted or
5074 directly be used as a file system container image with the
5075 @uref{https://singularity.lbl.gov, Singularity container execution
5076 environment}, using commands like @command{singularity shell} or
5077 @command{singularity exec}.
5079 Several command-line options allow you to customize your pack:
5082 @item --format=@var{format}
5083 @itemx -f @var{format}
5084 Produce a pack in the given @var{format}.
5086 The available formats are:
5090 This is the default format. It produces a tarball containing all the
5091 specified binaries and symlinks.
5094 This produces a tarball that follows the
5095 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5096 Docker Image Specification}. The ``repository name'' as it appears in
5097 the output of the @command{docker images} command is computed from
5098 package names passed on the command line or in the manifest file.
5101 This produces a SquashFS image containing all the specified binaries and
5102 symlinks, as well as empty mount points for virtual file systems like
5106 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5107 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5108 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5109 with something like:
5112 guix pack -f squashfs bash @dots{}
5115 If you forget the @code{bash} (or similar) package, @command{singularity
5116 run} and @command{singularity exec} will fail with an unhelpful ``no
5117 such file or directory'' message.
5121 @cindex relocatable binaries
5124 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5125 anywhere in the file system hierarchy and run from there.
5127 When this option is passed once, the resulting binaries require support for
5128 @dfn{user namespaces} in the kernel Linux; when passed
5129 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5130 PRoot support, can be thought of as the abbreviation of ``Really
5131 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5132 if user namespaces are unavailable, and essentially work anywhere---see below
5133 for the implications.
5135 For example, if you create a pack containing Bash with:
5138 guix pack -RR -S /mybin=bin bash
5142 ...@: you can copy that pack to a machine that lacks Guix, and from your
5143 home directory as a normal user, run:
5151 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5152 @file{/gnu/store} shows up and contains all the dependencies of
5153 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5154 altogether! That is probably the simplest way to deploy Guix-built
5155 software on a non-Guix machine.
5158 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5159 the kernel Linux, which allows unprivileged users to mount or change root.
5160 Old versions of Linux did not support it, and some GNU/Linux distributions
5163 To produce relocatable binaries that work even in the absence of user
5164 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5165 case, binaries will try user namespace support and fall back to PRoot if user
5166 namespaces are not supported.
5168 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5169 support for file system virtualization. It achieves that by using the
5170 @code{ptrace} system call on the running program. This approach has the
5171 advantage to work without requiring special kernel support, but it incurs
5172 run-time overhead every time a system call is made.
5175 @cindex entry point, for Docker images
5176 @item --entry-point=@var{command}
5177 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5178 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5179 support it. @var{command} must be relative to the profile contained in the
5182 The entry point specifies the command that tools like @code{docker run} or
5183 @code{singularity run} automatically start by default. For example, you can
5187 guix pack -f docker --entry-point=bin/guile guile
5190 The resulting pack can easily be loaded and @code{docker run} with no extra
5191 arguments will spawn @code{bin/guile}:
5194 docker load -i pack.tar.gz
5195 docker run @var{image-id}
5198 @item --expression=@var{expr}
5199 @itemx -e @var{expr}
5200 Consider the package @var{expr} evaluates to.
5202 This has the same purpose as the same-named option in @command{guix
5203 build} (@pxref{Additional Build Options, @code{--expression} in
5204 @command{guix build}}).
5206 @item --manifest=@var{file}
5207 @itemx -m @var{file}
5208 Use the packages contained in the manifest object returned by the Scheme
5209 code in @var{file}. This option can be repeated several times, in which
5210 case the manifests are concatenated.
5212 This has a similar purpose as the same-named option in @command{guix
5213 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5214 same manifest files. It allows you to define a collection of packages
5215 once and use it both for creating profiles and for creating archives
5216 for use on machines that do not have Guix installed. Note that you can
5217 specify @emph{either} a manifest file @emph{or} a list of packages,
5220 @item --system=@var{system}
5221 @itemx -s @var{system}
5222 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5223 the system type of the build host.
5225 @item --target=@var{triplet}
5226 @cindex cross-compilation
5227 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5228 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5229 configuration triplets,, autoconf, Autoconf}).
5231 @item --compression=@var{tool}
5232 @itemx -C @var{tool}
5233 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5234 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5236 @item --symlink=@var{spec}
5237 @itemx -S @var{spec}
5238 Add the symlinks specified by @var{spec} to the pack. This option can
5239 appear several times.
5241 @var{spec} has the form @code{@var{source}=@var{target}}, where
5242 @var{source} is the symlink that will be created and @var{target} is the
5245 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5246 symlink pointing to the @file{bin} sub-directory of the profile.
5248 @item --save-provenance
5249 Save provenance information for the packages passed on the command line.
5250 Provenance information includes the URL and commit of the channels in use
5253 Provenance information is saved in the
5254 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5255 usual package metadata---the name and version of each package, their
5256 propagated inputs, and so on. It is useful information to the recipient of
5257 the pack, who then knows how the pack was (supposedly) obtained.
5259 This option is not enabled by default because, like timestamps, provenance
5260 information contributes nothing to the build process. In other words, there
5261 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5262 Recording such ``silent'' metadata in the output thus potentially breaks the
5263 source-to-binary bitwise reproducibility property.
5265 @item --root=@var{file}
5266 @itemx -r @var{file}
5267 @cindex garbage collector root, for packs
5268 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5271 @item --localstatedir
5272 @itemx --profile-name=@var{name}
5273 Include the ``local state directory'', @file{/var/guix}, in the resulting
5274 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5275 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5276 @file{~root/.guix-profile}.
5278 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5279 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5280 the pack means that the store is ``complete'' and manageable by Guix;
5281 not providing it pack means that the store is ``dead'': items cannot be
5282 added to it or removed from it after extraction of the pack.
5284 One use case for this is the Guix self-contained binary tarball
5285 (@pxref{Binary Installation}).
5289 Print the name of the derivation that builds the pack.
5292 Use the bootstrap binaries to build the pack. This option is only
5293 useful to Guix developers.
5296 In addition, @command{guix pack} supports all the common build options
5297 (@pxref{Common Build Options}) and all the package transformation
5298 options (@pxref{Package Transformation Options}).
5301 @c *********************************************************************
5302 @node Programming Interface
5303 @chapter Programming Interface
5305 GNU Guix provides several Scheme programming interfaces (APIs) to
5306 define, build, and query packages. The first interface allows users to
5307 write high-level package definitions. These definitions refer to
5308 familiar packaging concepts, such as the name and version of a package,
5309 its build system, and its dependencies. These definitions can then be
5310 turned into concrete build actions.
5312 Build actions are performed by the Guix daemon, on behalf of users. In a
5313 standard setup, the daemon has write access to the store---the
5314 @file{/gnu/store} directory---whereas users do not. The recommended
5315 setup also has the daemon perform builds in chroots, under a specific
5316 build users, to minimize interference with the rest of the system.
5319 Lower-level APIs are available to interact with the daemon and the
5320 store. To instruct the daemon to perform a build action, users actually
5321 provide it with a @dfn{derivation}. A derivation is a low-level
5322 representation of the build actions to be taken, and the environment in
5323 which they should occur---derivations are to package definitions what
5324 assembly is to C programs. The term ``derivation'' comes from the fact
5325 that build results @emph{derive} from them.
5327 This chapter describes all these APIs in turn, starting from high-level
5328 package definitions.
5331 * Package Modules:: Packages from the programmer's viewpoint.
5332 * Defining Packages:: Defining new packages.
5333 * Build Systems:: Specifying how packages are built.
5334 * The Store:: Manipulating the package store.
5335 * Derivations:: Low-level interface to package derivations.
5336 * The Store Monad:: Purely functional interface to the store.
5337 * G-Expressions:: Manipulating build expressions.
5338 * Invoking guix repl:: Fiddling with Guix interactively.
5341 @node Package Modules
5342 @section Package Modules
5344 From a programming viewpoint, the package definitions of the
5345 GNU distribution are provided by Guile modules in the @code{(gnu packages
5346 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5347 packages @dots{})} module name space are not necessarily ``GNU
5348 packages''. This module naming scheme follows the usual Guile module
5349 naming convention: @code{gnu} means that these modules are distributed
5350 as part of the GNU system, and @code{packages} identifies modules that
5351 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5352 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5353 module exports a variable named @code{emacs}, which is bound to a
5354 @code{<package>} object (@pxref{Defining Packages}).
5356 The @code{(gnu packages @dots{})} module name space is
5357 automatically scanned for packages by the command-line tools. For
5358 instance, when running @code{guix install emacs}, all the @code{(gnu
5359 packages @dots{})} modules are scanned until one that exports a package
5360 object whose name is @code{emacs} is found. This package search
5361 facility is implemented in the @code{(gnu packages)} module.
5363 @cindex customization, of packages
5364 @cindex package module search path
5365 Users can store package definitions in modules with different
5366 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5367 name and module name must match. For instance, the @code{(my-packages
5368 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5369 relative to the load path specified with @option{--load-path} or
5370 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5371 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5372 these package definitions visible to the user interfaces:
5376 By adding the directory containing your package modules to the search path
5377 with the @code{-L} flag of @command{guix package} and other commands
5378 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5379 environment variable described below.
5382 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5383 pulls from it. A channel is essentially a Git repository containing package
5384 modules. @xref{Channels}, for more information on how to define and use
5388 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5390 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5391 This is a colon-separated list of directories to search for additional
5392 package modules. Directories listed in this variable take precedence
5393 over the own modules of the distribution.
5396 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5397 each package is built based solely on other packages in the
5398 distribution. The root of this dependency graph is a small set of
5399 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5400 bootstrap)} module. For more information on bootstrapping,
5401 @pxref{Bootstrapping}.
5403 @node Defining Packages
5404 @section Defining Packages
5406 The high-level interface to package definitions is implemented in the
5407 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5408 example, the package definition, or @dfn{recipe}, for the GNU Hello
5409 package looks like this:
5412 (define-module (gnu packages hello)
5413 #:use-module (guix packages)
5414 #:use-module (guix download)
5415 #:use-module (guix build-system gnu)
5416 #:use-module (guix licenses)
5417 #:use-module (gnu packages gawk))
5419 (define-public hello
5425 (uri (string-append "mirror://gnu/hello/hello-" version
5429 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5430 (build-system gnu-build-system)
5431 (arguments '(#:configure-flags '("--enable-silent-rules")))
5432 (inputs `(("gawk" ,gawk)))
5433 (synopsis "Hello, GNU world: An example GNU package")
5434 (description "Guess what GNU Hello prints!")
5435 (home-page "https://www.gnu.org/software/hello/")
5440 Without being a Scheme expert, the reader may have guessed the meaning
5441 of the various fields here. This expression binds the variable
5442 @code{hello} to a @code{<package>} object, which is essentially a record
5443 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5444 This package object can be inspected using procedures found in the
5445 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5446 returns---surprise!---@code{"hello"}.
5448 With luck, you may be able to import part or all of the definition of
5449 the package you are interested in from another repository, using the
5450 @code{guix import} command (@pxref{Invoking guix import}).
5452 In the example above, @var{hello} is defined in a module of its own,
5453 @code{(gnu packages hello)}. Technically, this is not strictly
5454 necessary, but it is convenient to do so: all the packages defined in
5455 modules under @code{(gnu packages @dots{})} are automatically known to
5456 the command-line tools (@pxref{Package Modules}).
5458 There are a few points worth noting in the above package definition:
5462 The @code{source} field of the package is an @code{<origin>} object
5463 (@pxref{origin Reference}, for the complete reference).
5464 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5465 meaning that the source is a file to be downloaded over FTP or HTTP.
5467 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5468 the GNU mirrors defined in @code{(guix download)}.
5470 The @code{sha256} field specifies the expected SHA256 hash of the file
5471 being downloaded. It is mandatory, and allows Guix to check the
5472 integrity of the file. The @code{(base32 @dots{})} form introduces the
5473 base32 representation of the hash. You can obtain this information with
5474 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5475 hash} (@pxref{Invoking guix hash}).
5478 When needed, the @code{origin} form can also have a @code{patches} field
5479 listing patches to be applied, and a @code{snippet} field giving a
5480 Scheme expression to modify the source code.
5483 @cindex GNU Build System
5484 The @code{build-system} field specifies the procedure to build the
5485 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5486 represents the familiar GNU Build System, where packages may be
5487 configured, built, and installed with the usual @code{./configure &&
5488 make && make check && make install} command sequence.
5491 The @code{arguments} field specifies options for the build system
5492 (@pxref{Build Systems}). Here it is interpreted by
5493 @var{gnu-build-system} as a request run @file{configure} with the
5494 @code{--enable-silent-rules} flag.
5500 What about these quote (@code{'}) characters? They are Scheme syntax to
5501 introduce a literal list; @code{'} is synonymous with @code{quote}.
5502 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5503 for details. Here the value of the @code{arguments} field is a list of
5504 arguments passed to the build system down the road, as with @code{apply}
5505 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5508 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5509 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5510 @code{#:configure-flags} is a keyword used to pass a keyword argument
5511 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5515 The @code{inputs} field specifies inputs to the build process---i.e.,
5516 build-time or run-time dependencies of the package. Here, we define an
5517 input called @code{"gawk"} whose value is that of the @var{gawk}
5518 variable; @var{gawk} is itself bound to a @code{<package>} object.
5520 @cindex backquote (quasiquote)
5523 @cindex comma (unquote)
5527 @findex unquote-splicing
5528 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5529 us to introduce a literal list in the @code{inputs} field, while
5530 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5531 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5534 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5535 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5536 of ensuring that they are present (@pxref{Build Systems}).
5538 However, any other dependencies need to be specified in the
5539 @code{inputs} field. Any dependency not specified here will simply be
5540 unavailable to the build process, possibly leading to a build failure.
5543 @xref{package Reference}, for a full description of possible fields.
5545 Once a package definition is in place, the
5546 package may actually be built using the @code{guix build} command-line
5547 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5548 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5549 package definition using the @command{guix edit} command
5550 (@pxref{Invoking guix edit}).
5551 @xref{Packaging Guidelines}, for
5552 more information on how to test package definitions, and
5553 @ref{Invoking guix lint}, for information on how to check a definition
5554 for style conformance.
5555 @vindex GUIX_PACKAGE_PATH
5556 Lastly, @pxref{Channels}, for information
5557 on how to extend the distribution by adding your own package definitions
5560 Finally, updating the package definition to a new upstream version
5561 can be partly automated by the @command{guix refresh} command
5562 (@pxref{Invoking guix refresh}).
5564 Behind the scenes, a derivation corresponding to the @code{<package>}
5565 object is first computed by the @code{package-derivation} procedure.
5566 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5567 The build actions it prescribes may then be realized by using the
5568 @code{build-derivations} procedure (@pxref{The Store}).
5570 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5571 Return the @code{<derivation>} object of @var{package} for @var{system}
5572 (@pxref{Derivations}).
5574 @var{package} must be a valid @code{<package>} object, and @var{system}
5575 must be a string denoting the target system type---e.g.,
5576 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5577 must be a connection to the daemon, which operates on the store
5578 (@pxref{The Store}).
5582 @cindex cross-compilation
5583 Similarly, it is possible to compute a derivation that cross-builds a
5584 package for some other system:
5586 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5587 @var{package} @var{target} [@var{system}]
5588 Return the @code{<derivation>} object of @var{package} cross-built from
5589 @var{system} to @var{target}.
5591 @var{target} must be a valid GNU triplet denoting the target hardware
5592 and operating system, such as @code{"mips64el-linux-gnu"}
5593 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5596 @cindex package transformations
5597 @cindex input rewriting
5598 @cindex dependency tree rewriting
5599 Packages can be manipulated in arbitrary ways. An example of a useful
5600 transformation is @dfn{input rewriting}, whereby the dependency tree of
5601 a package is rewritten by replacing specific inputs by others:
5603 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5604 [@var{rewrite-name}]
5605 Return a procedure that, when passed a package, replaces its direct and
5606 indirect dependencies (but not its implicit inputs) according to
5607 @var{replacements}. @var{replacements} is a list of package pairs; the
5608 first element of each pair is the package to replace, and the second one
5611 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5612 the name of a package and returns its new name after rewrite.
5616 Consider this example:
5619 (define libressl-instead-of-openssl
5620 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5622 (package-input-rewriting `((,openssl . ,libressl))))
5624 (define git-with-libressl
5625 (libressl-instead-of-openssl git))
5629 Here we first define a rewriting procedure that replaces @var{openssl}
5630 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5631 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5632 This is exactly what the @option{--with-input} command-line option does
5633 (@pxref{Package Transformation Options, @option{--with-input}}).
5635 The following variant of @code{package-input-rewriting} can match packages to
5636 be replaced by name rather than by identity.
5638 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5639 Return a procedure that, given a package, applies the given @var{replacements} to
5640 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5641 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5642 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5643 replacement for that package.
5646 The example above could be rewritten this way:
5649 (define libressl-instead-of-openssl
5650 ;; Replace all the packages called "openssl" with LibreSSL.
5651 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5654 The key difference here is that, this time, packages are matched by spec and
5655 not by identity. In other words, any package in the graph that is called
5656 @code{openssl} will be replaced.
5658 A more generic procedure to rewrite a package dependency graph is
5659 @code{package-mapping}: it supports arbitrary changes to nodes in the
5662 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5663 Return a procedure that, given a package, applies @var{proc} to all the packages
5664 depended on and returns the resulting package. The procedure stops recursion
5665 when @var{cut?} returns true for a given package.
5669 * package Reference:: The package data type.
5670 * origin Reference:: The origin data type.
5674 @node package Reference
5675 @subsection @code{package} Reference
5677 This section summarizes all the options available in @code{package}
5678 declarations (@pxref{Defining Packages}).
5680 @deftp {Data Type} package
5681 This is the data type representing a package recipe.
5685 The name of the package, as a string.
5687 @item @code{version}
5688 The version of the package, as a string.
5691 An object telling how the source code for the package should be
5692 acquired. Most of the time, this is an @code{origin} object, which
5693 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5694 can also be any other ``file-like'' object such as a @code{local-file},
5695 which denotes a file from the local file system (@pxref{G-Expressions,
5696 @code{local-file}}).
5698 @item @code{build-system}
5699 The build system that should be used to build the package (@pxref{Build
5702 @item @code{arguments} (default: @code{'()})
5703 The arguments that should be passed to the build system. This is a
5704 list, typically containing sequential keyword-value pairs.
5706 @item @code{inputs} (default: @code{'()})
5707 @itemx @code{native-inputs} (default: @code{'()})
5708 @itemx @code{propagated-inputs} (default: @code{'()})
5709 @cindex inputs, of packages
5710 These fields list dependencies of the package. Each one is a list of
5711 tuples, where each tuple has a label for the input (a string) as its
5712 first element, a package, origin, or derivation as its second element,
5713 and optionally the name of the output thereof that should be used, which
5714 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5715 more on package outputs). For example, the list below specifies three
5719 `(("libffi" ,libffi)
5720 ("libunistring" ,libunistring)
5721 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5724 @cindex cross compilation, package dependencies
5725 The distinction between @code{native-inputs} and @code{inputs} is
5726 necessary when considering cross-compilation. When cross-compiling,
5727 dependencies listed in @code{inputs} are built for the @emph{target}
5728 architecture; conversely, dependencies listed in @code{native-inputs}
5729 are built for the architecture of the @emph{build} machine.
5731 @code{native-inputs} is typically used to list tools needed at
5732 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5733 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5734 this area (@pxref{Invoking guix lint}).
5736 @anchor{package-propagated-inputs}
5737 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5738 specified packages will be automatically installed alongside the package
5739 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5740 package}}, for information on how @command{guix package} deals with
5743 For example this is necessary when a C/C++ library needs headers of
5744 another library to compile, or when a pkg-config file refers to another
5745 one @i{via} its @code{Requires} field.
5747 Another example where @code{propagated-inputs} is useful is for languages
5748 that lack a facility to record the run-time search path akin to the
5749 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5750 more. To ensure that libraries written in those languages can find
5751 library code they depend on at run time, run-time dependencies must be
5752 listed in @code{propagated-inputs} rather than @code{inputs}.
5754 @item @code{outputs} (default: @code{'("out")})
5755 The list of output names of the package. @xref{Packages with Multiple
5756 Outputs}, for typical uses of additional outputs.
5758 @item @code{native-search-paths} (default: @code{'()})
5759 @itemx @code{search-paths} (default: @code{'()})
5760 A list of @code{search-path-specification} objects describing
5761 search-path environment variables honored by the package.
5763 @item @code{replacement} (default: @code{#f})
5764 This must be either @code{#f} or a package object that will be used as a
5765 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5768 @item @code{synopsis}
5769 A one-line description of the package.
5771 @item @code{description}
5772 A more elaborate description of the package.
5774 @item @code{license}
5775 @cindex license, of packages
5776 The license of the package; a value from @code{(guix licenses)},
5777 or a list of such values.
5779 @item @code{home-page}
5780 The URL to the home-page of the package, as a string.
5782 @item @code{supported-systems} (default: @var{%supported-systems})
5783 The list of systems supported by the package, as strings of the form
5784 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5786 @item @code{location} (default: source location of the @code{package} form)
5787 The source location of the package. It is useful to override this when
5788 inheriting from another package, in which case this field is not
5789 automatically corrected.
5793 @deffn {Scheme Syntax} this-package
5794 When used in the @emph{lexical scope} of a package field definition, this
5795 identifier resolves to the package being defined.
5797 The example below shows how to add a package as a native input of itself when
5805 ;; When cross-compiled, Guile, for example, depends on
5806 ;; a native version of itself. Add it here.
5807 (native-inputs (if (%current-target-system)
5808 `(("self" ,this-package))
5812 It is an error to refer to @code{this-package} outside a package definition.
5815 @node origin Reference
5816 @subsection @code{origin} Reference
5818 This section summarizes all the options available in @code{origin}
5819 declarations (@pxref{Defining Packages}).
5821 @deftp {Data Type} origin
5822 This is the data type representing a source code origin.
5826 An object containing the URI of the source. The object type depends on
5827 the @code{method} (see below). For example, when using the
5828 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5829 values are: a URL represented as a string, or a list thereof.
5832 A procedure that handles the URI.
5837 @item @var{url-fetch} from @code{(guix download)}
5838 download a file from the HTTP, HTTPS, or FTP URL specified in the
5842 @item @var{git-fetch} from @code{(guix git-download)}
5843 clone the Git version control repository, and check out the revision
5844 specified in the @code{uri} field as a @code{git-reference} object; a
5845 @code{git-reference} looks like this:
5849 (url "https://git.savannah.gnu.org/git/hello.git")
5855 A bytevector containing the SHA-256 hash of the source. Typically the
5856 @code{base32} form is used here to generate the bytevector from a
5859 You can obtain this information using @code{guix download}
5860 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5863 @item @code{file-name} (default: @code{#f})
5864 The file name under which the source code should be saved. When this is
5865 @code{#f}, a sensible default value will be used in most cases. In case
5866 the source is fetched from a URL, the file name from the URL will be
5867 used. For version control checkouts, it is recommended to provide the
5868 file name explicitly because the default is not very descriptive.
5870 @item @code{patches} (default: @code{'()})
5871 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5872 file-like objects}) pointing to patches to be applied to the source.
5874 This list of patches must be unconditional. In particular, it cannot
5875 depend on the value of @code{%current-system} or
5876 @code{%current-target-system}.
5878 @item @code{snippet} (default: @code{#f})
5879 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5880 in the source directory. This is a convenient way to modify the source,
5881 sometimes more convenient than a patch.
5883 @item @code{patch-flags} (default: @code{'("-p1")})
5884 A list of command-line flags that should be passed to the @code{patch}
5887 @item @code{patch-inputs} (default: @code{#f})
5888 Input packages or derivations to the patching process. When this is
5889 @code{#f}, the usual set of inputs necessary for patching are provided,
5890 such as GNU@tie{}Patch.
5892 @item @code{modules} (default: @code{'()})
5893 A list of Guile modules that should be loaded during the patching
5894 process and while running the code in the @code{snippet} field.
5896 @item @code{patch-guile} (default: @code{#f})
5897 The Guile package that should be used in the patching process. When
5898 this is @code{#f}, a sensible default is used.
5904 @section Build Systems
5906 @cindex build system
5907 Each package definition specifies a @dfn{build system} and arguments for
5908 that build system (@pxref{Defining Packages}). This @code{build-system}
5909 field represents the build procedure of the package, as well as implicit
5910 dependencies of that build procedure.
5912 Build systems are @code{<build-system>} objects. The interface to
5913 create and manipulate them is provided by the @code{(guix build-system)}
5914 module, and actual build systems are exported by specific modules.
5916 @cindex bag (low-level package representation)
5917 Under the hood, build systems first compile package objects to
5918 @dfn{bags}. A @dfn{bag} is like a package, but with less
5919 ornamentation---in other words, a bag is a lower-level representation of
5920 a package, which includes all the inputs of that package, including some
5921 that were implicitly added by the build system. This intermediate
5922 representation is then compiled to a derivation (@pxref{Derivations}).
5924 Build systems accept an optional list of @dfn{arguments}. In package
5925 definitions, these are passed @i{via} the @code{arguments} field
5926 (@pxref{Defining Packages}). They are typically keyword arguments
5927 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5928 Guile Reference Manual}). The value of these arguments is usually
5929 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5930 by the daemon (@pxref{Derivations}).
5932 The main build system is @var{gnu-build-system}, which implements the
5933 standard build procedure for GNU and many other packages. It
5934 is provided by the @code{(guix build-system gnu)} module.
5936 @defvr {Scheme Variable} gnu-build-system
5937 @var{gnu-build-system} represents the GNU Build System, and variants
5938 thereof (@pxref{Configuration, configuration and makefile conventions,,
5939 standards, GNU Coding Standards}).
5941 @cindex build phases
5942 In a nutshell, packages using it are configured, built, and installed with
5943 the usual @code{./configure && make && make check && make install}
5944 command sequence. In practice, a few additional steps are often needed.
5945 All these steps are split up in separate @dfn{phases},
5946 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5947 modules for more details about the build phases.}:
5951 Unpack the source tarball, and change the current directory to the
5952 extracted source tree. If the source is actually a directory, copy it
5953 to the build tree, and enter that directory.
5955 @item patch-source-shebangs
5956 Patch shebangs encountered in source files so they refer to the right
5957 store file names. For instance, this changes @code{#!/bin/sh} to
5958 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5961 Run the @file{configure} script with a number of default options, such
5962 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5963 by the @code{#:configure-flags} argument.
5966 Run @code{make} with the list of flags specified with
5967 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5968 (the default), build with @code{make -j}.
5971 Run @code{make check}, or some other target specified with
5972 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5973 @code{#:parallel-tests?} argument is true (the default), run @code{make
5977 Run @code{make install} with the flags listed in @code{#:make-flags}.
5979 @item patch-shebangs
5980 Patch shebangs on the installed executable files.
5983 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5984 is false), copying them to the @code{debug} output when available
5985 (@pxref{Installing Debugging Files}).
5988 @vindex %standard-phases
5989 The build-side module @code{(guix build gnu-build-system)} defines
5990 @var{%standard-phases} as the default list of build phases.
5991 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5992 procedure implements the actual phase.
5994 The list of phases used for a particular package can be changed with the
5995 @code{#:phases} parameter. For instance, passing:
5998 #:phases (modify-phases %standard-phases (delete 'configure))
6001 means that all the phases described above will be used, except the
6002 @code{configure} phase.
6004 In addition, this build system ensures that the ``standard'' environment
6005 for GNU packages is available. This includes tools such as GCC, libc,
6006 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6007 build-system gnu)} module for a complete list). We call these the
6008 @dfn{implicit inputs} of a package, because package definitions do not
6009 have to mention them.
6012 Other @code{<build-system>} objects are defined to support other
6013 conventions and tools used by free software packages. They inherit most
6014 of @var{gnu-build-system}, and differ mainly in the set of inputs
6015 implicitly added to the build process, and in the list of phases
6016 executed. Some of these build systems are listed below.
6018 @defvr {Scheme Variable} ant-build-system
6019 This variable is exported by @code{(guix build-system ant)}. It
6020 implements the build procedure for Java packages that can be built with
6021 @url{https://ant.apache.org/, Ant build tool}.
6023 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6024 provided by the @code{icedtea} package to the set of inputs. Different
6025 packages can be specified with the @code{#:ant} and @code{#:jdk}
6026 parameters, respectively.
6028 When the original package does not provide a suitable Ant build file,
6029 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6030 build file @file{build.xml} with tasks to build the specified jar
6031 archive. In this case the parameter @code{#:source-dir} can be used to
6032 specify the source sub-directory, defaulting to ``src''.
6034 The @code{#:main-class} parameter can be used with the minimal ant
6035 buildfile to specify the main class of the resulting jar. This makes the
6036 jar file executable. The @code{#:test-include} parameter can be used to
6037 specify the list of junit tests to run. It defaults to
6038 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6039 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6040 because abstract classes cannot be run as tests.
6042 The parameter @code{#:build-target} can be used to specify the Ant task
6043 that should be run during the @code{build} phase. By default the
6044 ``jar'' task will be run.
6048 @defvr {Scheme Variable} android-ndk-build-system
6049 @cindex Android distribution
6050 @cindex Android NDK build system
6051 This variable is exported by @code{(guix build-system android-ndk)}. It
6052 implements a build procedure for Android NDK (native development kit)
6053 packages using a Guix-specific build process.
6055 The build system assumes that packages install their public interface
6056 (header) files to the subdirectory "include" of the "out" output and
6057 their libraries to the subdirectory "lib" of the "out" output.
6059 It's also assumed that the union of all the dependencies of a package
6060 has no conflicting files.
6062 For the time being, cross-compilation is not supported - so right now
6063 the libraries and header files are assumed to be host tools.
6067 @defvr {Scheme Variable} asdf-build-system/source
6068 @defvrx {Scheme Variable} asdf-build-system/sbcl
6069 @defvrx {Scheme Variable} asdf-build-system/ecl
6071 These variables, exported by @code{(guix build-system asdf)}, implement
6072 build procedures for Common Lisp packages using
6073 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6074 definition facility for Common Lisp programs and libraries.
6076 The @code{asdf-build-system/source} system installs the packages in
6077 source form, and can be loaded using any common lisp implementation, via
6078 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6079 systems in the format which a particular implementation understands.
6080 These build systems can also be used to produce executable programs, or
6081 lisp images which contain a set of packages pre-loaded.
6083 The build system uses naming conventions. For binary packages, the
6084 package name should be prefixed with the lisp implementation, such as
6085 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6087 Additionally, the corresponding source package should be labeled using
6088 the same convention as python packages (see @ref{Python Modules}), using
6089 the @code{cl-} prefix.
6091 For binary packages, each system should be defined as a Guix package.
6092 If one package @code{origin} contains several systems, package variants
6093 can be created in order to build all the systems. Source packages,
6094 which use @code{asdf-build-system/source}, may contain several systems.
6096 In order to create executable programs and images, the build-side
6097 procedures @code{build-program} and @code{build-image} can be used.
6098 They should be called in a build phase after the @code{create-symlinks}
6099 phase, so that the system which was just built can be used within the
6100 resulting image. @code{build-program} requires a list of Common Lisp
6101 expressions to be passed as the @code{#:entry-program} argument.
6103 If the system is not defined within its own @code{.asd} file of the same
6104 name, then the @code{#:asd-file} parameter should be used to specify
6105 which file the system is defined in. Furthermore, if the package
6106 defines a system for its tests in a separate file, it will be loaded
6107 before the tests are run if it is specified by the
6108 @code{#:test-asd-file} parameter. If it is not set, the files
6109 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6110 and @code{test.asd} will be tried if they exist.
6112 If for some reason the package must be named in a different way than the
6113 naming conventions suggest, the @code{#:asd-system-name} parameter can
6114 be used to specify the name of the system.
6118 @defvr {Scheme Variable} cargo-build-system
6119 @cindex Rust programming language
6120 @cindex Cargo (Rust build system)
6121 This variable is exported by @code{(guix build-system cargo)}. It
6122 supports builds of packages using Cargo, the build tool of the
6123 @uref{https://www.rust-lang.org, Rust programming language}.
6125 It adds @code{rustc} and @code{cargo} to the set of inputs.
6126 A different Rust package can be specified with the @code{#:rust} parameter.
6128 Regular cargo dependencies should be added to the package definition via the
6129 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6130 spec can be a package or a source definition. Note that the spec must
6131 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6132 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6133 should be added to the package definition via the
6134 @code{#:cargo-development-inputs} parameter.
6136 In its @code{configure} phase, this build system will make any source inputs
6137 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6138 parameters available to cargo. It will also remove an included
6139 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6140 @code{build} phase. The @code{install} phase installs any crate the binaries
6141 if they are defined by the crate.
6144 @cindex Clojure (programming language)
6145 @cindex simple Clojure build system
6146 @defvr {Scheme Variable} clojure-build-system
6147 This variable is exported by @code{(guix build-system clojure)}. It implements
6148 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6149 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6152 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6153 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6154 @code{#:zip} parameters, respectively.
6156 A list of source directories, test directories and jar names can be specified
6157 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6158 parameters, respectively. Compile directory and main class can be specified
6159 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6160 Other parameters are documented below.
6162 This build system is an extension of @var{ant-build-system}, but with the
6163 following phases changed:
6168 This phase calls @code{compile} in Clojure to compile source files and runs
6169 @command{jar} to create jars from both source files and compiled files
6170 according to the include list and exclude list specified in
6171 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6172 has priority over the include list. These lists consist of symbols
6173 representing Clojure libraries or the special keyword @code{#:all} representing
6174 all Clojure libraries found under the source directories. The parameter
6175 @code{#:omit-source?} decides if source should be included into the jars.
6178 This phase runs tests according to the include list and exclude list specified
6179 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6180 meanings are analogous to that of @code{#:aot-include} and
6181 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6182 stands for all Clojure libraries found under the test directories. The
6183 parameter @code{#:tests?} decides if tests should be run.
6186 This phase installs all jars built previously.
6189 Apart from the above, this build system also contains an additional phase:
6194 This phase installs all top-level files with base name matching
6195 @var{%doc-regex}. A different regex can be specified with the
6196 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6197 directories specified in @code{#:doc-dirs} are installed as well.
6201 @defvr {Scheme Variable} cmake-build-system
6202 This variable is exported by @code{(guix build-system cmake)}. It
6203 implements the build procedure for packages using the
6204 @url{https://www.cmake.org, CMake build tool}.
6206 It automatically adds the @code{cmake} package to the set of inputs.
6207 Which package is used can be specified with the @code{#:cmake}
6210 The @code{#:configure-flags} parameter is taken as a list of flags
6211 passed to the @command{cmake} command. The @code{#:build-type}
6212 parameter specifies in abstract terms the flags passed to the compiler;
6213 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6214 debugging information''), which roughly means that code is compiled with
6215 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6218 @defvr {Scheme Variable} dune-build-system
6219 This variable is exported by @code{(guix build-system dune)}. It
6220 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6221 tool for the OCaml programming language. It is implemented as an extension
6222 of the @code{ocaml-build-system} which is described below. As such, the
6223 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6226 It automatically adds the @code{dune} package to the set of inputs.
6227 Which package is used can be specified with the @code{#:dune}
6230 There is no @code{configure} phase because dune packages typically don't
6231 need to be configured. The @code{#:build-flags} parameter is taken as a
6232 list of flags passed to the @code{dune} command during the build.
6234 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6235 command instead of the more recent @code{dune} command while building
6236 a package. Its default value is @code{#f}.
6238 The @code{#:package} parameter can be passed to specify a package name, which
6239 is useful when a package contains multiple packages and you want to build
6240 only one of them. This is equivalent to passing the @code{-p} argument to
6244 @defvr {Scheme Variable} go-build-system
6245 This variable is exported by @code{(guix build-system go)}. It
6246 implements a build procedure for Go packages using the standard
6247 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6248 Go build mechanisms}.
6250 The user is expected to provide a value for the key @code{#:import-path}
6251 and, in some cases, @code{#:unpack-path}. The
6252 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6253 corresponds to the file system path expected by the package's build
6254 scripts and any referring packages, and provides a unique way to
6255 refer to a Go package. It is typically based on a combination of the
6256 package source code's remote URI and file system hierarchy structure. In
6257 some cases, you will need to unpack the package's source code to a
6258 different directory structure than the one indicated by the import path,
6259 and @code{#:unpack-path} should be used in such cases.
6261 Packages that provide Go libraries should install their source code into
6262 the built output. The key @code{#:install-source?}, which defaults to
6263 @code{#t}, controls whether or not the source code is installed. It can
6264 be set to @code{#f} for packages that only provide executable files.
6267 @defvr {Scheme Variable} glib-or-gtk-build-system
6268 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6269 is intended for use with packages making use of GLib or GTK+.
6271 This build system adds the following two phases to the ones defined by
6272 @var{gnu-build-system}:
6275 @item glib-or-gtk-wrap
6276 The phase @code{glib-or-gtk-wrap} ensures that programs in
6277 @file{bin/} are able to find GLib ``schemas'' and
6278 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6279 modules}. This is achieved by wrapping the programs in launch scripts
6280 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6281 environment variables.
6283 It is possible to exclude specific package outputs from that wrapping
6284 process by listing their names in the
6285 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6286 when an output is known not to contain any GLib or GTK+ binaries, and
6287 where wrapping would gratuitously add a dependency of that output on
6290 @item glib-or-gtk-compile-schemas
6291 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6292 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6293 GSettings schemas} of GLib are compiled. Compilation is performed by the
6294 @command{glib-compile-schemas} program. It is provided by the package
6295 @code{glib:bin} which is automatically imported by the build system.
6296 The @code{glib} package providing @command{glib-compile-schemas} can be
6297 specified with the @code{#:glib} parameter.
6300 Both phases are executed after the @code{install} phase.
6303 @defvr {Scheme Variable} guile-build-system
6304 This build system is for Guile packages that consist exclusively of Scheme
6305 code and that are so lean that they don't even have a makefile, let alone a
6306 @file{configure} script. It compiles Scheme code using @command{guild
6307 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6308 installs the @file{.scm} and @file{.go} files in the right place. It also
6309 installs documentation.
6311 This build system supports cross-compilation by using the @code{--target}
6312 option of @command{guild compile}.
6314 Packages built with @code{guile-build-system} must provide a Guile package in
6315 their @code{native-inputs} field.
6318 @defvr {Scheme Variable} julia-build-system
6319 This variable is exported by @code{(guix build-system julia)}. It implements
6320 the build procedure used by @uref{https://julialang.org/, julia} packages,
6321 which essentially is similar to running @command{julia -e 'using Pkg;
6322 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6323 paths to all Julia package inputs. Tests are run not run.
6325 Julia packages require the source @code{file-name} to be the real name of the
6326 package, correctly capitalized.
6328 For packages requiring shared library dependencies, you may need to write the
6329 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6330 variable = /gnu/store/library.so} for each dependency, plus a void function
6331 @code{check_deps() = nothing}.
6333 Some older packages that aren't using @file{Package.toml} yet, will require
6334 this file to be created, too. The function @code{julia-create-package-toml}
6335 helps creating the file. You need to pass the outputs and the source of the
6336 package, it's name (the same as the @code{file-name} parameter), the package
6337 uuid, the package version, and a list of dependencies specified by their name
6341 @defvr {Scheme Variable} minify-build-system
6342 This variable is exported by @code{(guix build-system minify)}. It
6343 implements a minification procedure for simple JavaScript packages.
6345 It adds @code{uglify-js} to the set of inputs and uses it to compress
6346 all JavaScript files in the @file{src} directory. A different minifier
6347 package can be specified with the @code{#:uglify-js} parameter, but it
6348 is expected that the package writes the minified code to the standard
6351 When the input JavaScript files are not all located in the @file{src}
6352 directory, the parameter @code{#:javascript-files} can be used to
6353 specify a list of file names to feed to the minifier.
6356 @defvr {Scheme Variable} ocaml-build-system
6357 This variable is exported by @code{(guix build-system ocaml)}. It implements
6358 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6359 of choosing the correct set of commands to run for each package. OCaml
6360 packages can expect many different commands to be run. This build system will
6363 When the package has a @file{setup.ml} file present at the top-level, it will
6364 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6365 @code{ocaml setup.ml -install}. The build system will assume that this file
6366 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6367 care of setting the prefix and enabling tests if they are not disabled. You
6368 can pass configure and build flags with the @code{#:configure-flags} and
6369 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6370 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6371 bypass this system in the build and install phases.
6373 When the package has a @file{configure} file, it is assumed that it is a
6374 hand-made configure script that requires a different argument format than
6375 in the @code{gnu-build-system}. You can add more flags with the
6376 @code{#:configure-flags} key.
6378 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6379 @code{#t}), it will be used and more flags can be passed to the build and
6380 install phases with the @code{#:make-flags} key.
6382 Finally, some packages do not have these files and use a somewhat standard
6383 location for its build system. In that case, the build system will run
6384 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6385 providing the path to the required findlib module. Additional flags can
6386 be passed via the @code{#:build-flags} key. Install is taken care of by
6387 @command{opam-installer}. In this case, the @code{opam} package must
6388 be added to the @code{native-inputs} field of the package definition.
6390 Note that most OCaml packages assume they will be installed in the same
6391 directory as OCaml, which is not what we want in guix. In particular, they
6392 will install @file{.so} files in their module's directory, which is usually
6393 fine because it is in the OCaml compiler directory. In guix though, these
6394 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6395 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6396 @file{.so} libraries should be installed.
6399 @defvr {Scheme Variable} python-build-system
6400 This variable is exported by @code{(guix build-system python)}. It
6401 implements the more or less standard build procedure used by Python
6402 packages, which consists in running @code{python setup.py build} and
6403 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6405 For packages that install stand-alone Python programs under @code{bin/},
6406 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6407 environment variable points to all the Python libraries they depend on.
6409 Which Python package is used to perform the build can be specified with
6410 the @code{#:python} parameter. This is a useful way to force a package
6411 to be built for a specific version of the Python interpreter, which
6412 might be necessary if the package is only compatible with a single
6413 interpreter version.
6415 By default guix calls @code{setup.py} under control of
6416 @code{setuptools}, much like @command{pip} does. Some packages are not
6417 compatible with setuptools (and pip), thus you can disable this by
6418 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6421 @defvr {Scheme Variable} perl-build-system
6422 This variable is exported by @code{(guix build-system perl)}. It
6423 implements the standard build procedure for Perl packages, which either
6424 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6425 followed by @code{Build} and @code{Build install}; or in running
6426 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6427 @code{make} and @code{make install}, depending on which of
6428 @code{Build.PL} or @code{Makefile.PL} is present in the package
6429 distribution. Preference is given to the former if both @code{Build.PL}
6430 and @code{Makefile.PL} exist in the package distribution. This
6431 preference can be reversed by specifying @code{#t} for the
6432 @code{#:make-maker?} parameter.
6434 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6435 passes flags specified by the @code{#:make-maker-flags} or
6436 @code{#:module-build-flags} parameter, respectively.
6438 Which Perl package is used can be specified with @code{#:perl}.
6441 @defvr {Scheme Variable} qt-build-system
6442 This variable is exported by @code{(guix build-system qt)}. It
6443 is intended for use with applications using Qt or KDE.
6445 This build system adds the phase @code{qt-wrap} to the ones defined by
6446 @var{cmake-build-system}, after the @code{install} phase.
6448 This phase searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6449 and output. In case some path is found, all programs in the output's
6450 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6451 are wrapped in scripts defining the necessary environment variables.
6453 It is possible to exclude specific package outputs from that wrapping process
6454 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6455 This is useful when an output is known not to contain any Qt binaries, and
6456 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6460 @defvr {Scheme Variable} r-build-system
6461 This variable is exported by @code{(guix build-system r)}. It
6462 implements the build procedure used by @uref{https://r-project.org, R}
6463 packages, which essentially is little more than running @code{R CMD
6464 INSTALL --library=/gnu/store/@dots{}} in an environment where
6465 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6466 are run after installation using the R function
6467 @code{tools::testInstalledPackage}.
6470 @defvr {Scheme Variable} rakudo-build-system
6471 This variable is exported by @code{(guix build-system rakudo)}. It
6472 implements the build procedure used by @uref{https://rakudo.org/,
6473 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6474 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6475 installs the binaries, library files and the resources, as well as wrap
6476 the files under the @code{bin/} directory. Tests can be skipped by
6477 passing @code{#f} to the @code{tests?} parameter.
6479 Which rakudo package is used can be specified with @code{rakudo}.
6480 Which perl6-tap-harness package used for the tests can be specified with
6481 @code{#:prove6} or removed by passing @code{#f} to the
6482 @code{with-prove6?} parameter.
6483 Which perl6-zef package used for tests and installing can be specified
6484 with @code{#:zef} or removed by passing @code{#f} to the
6485 @code{with-zef?} parameter.
6488 @defvr {Scheme Variable} texlive-build-system
6489 This variable is exported by @code{(guix build-system texlive)}. It is
6490 used to build TeX packages in batch mode with a specified engine. The
6491 build system sets the @code{TEXINPUTS} variable to find all TeX source
6492 files in the inputs.
6494 By default it runs @code{luatex} on all files ending on @code{ins}. A
6495 different engine and format can be specified with the
6496 @code{#:tex-format} argument. Different build targets can be specified
6497 with the @code{#:build-targets} argument, which expects a list of file
6498 names. The build system adds only @code{texlive-bin} and
6499 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6500 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6501 and @code{#:texlive-latex-base}, respectively.
6503 The @code{#:tex-directory} parameter tells the build system where to
6504 install the built files under the texmf tree.
6507 @defvr {Scheme Variable} ruby-build-system
6508 This variable is exported by @code{(guix build-system ruby)}. It
6509 implements the RubyGems build procedure used by Ruby packages, which
6510 involves running @code{gem build} followed by @code{gem install}.
6512 The @code{source} field of a package that uses this build system
6513 typically references a gem archive, since this is the format that Ruby
6514 developers use when releasing their software. The build system unpacks
6515 the gem archive, potentially patches the source, runs the test suite,
6516 repackages the gem, and installs it. Additionally, directories and
6517 tarballs may be referenced to allow building unreleased gems from Git or
6518 a traditional source release tarball.
6520 Which Ruby package is used can be specified with the @code{#:ruby}
6521 parameter. A list of additional flags to be passed to the @command{gem}
6522 command can be specified with the @code{#:gem-flags} parameter.
6525 @defvr {Scheme Variable} waf-build-system
6526 This variable is exported by @code{(guix build-system waf)}. It
6527 implements a build procedure around the @code{waf} script. The common
6528 phases---@code{configure}, @code{build}, and @code{install}---are
6529 implemented by passing their names as arguments to the @code{waf}
6532 The @code{waf} script is executed by the Python interpreter. Which
6533 Python package is used to run the script can be specified with the
6534 @code{#:python} parameter.
6537 @defvr {Scheme Variable} scons-build-system
6538 This variable is exported by @code{(guix build-system scons)}. It
6539 implements the build procedure used by the SCons software construction
6540 tool. This build system runs @code{scons} to build the package,
6541 @code{scons test} to run tests, and then @code{scons install} to install
6544 Additional flags to be passed to @code{scons} can be specified with the
6545 @code{#:scons-flags} parameter. The default build and install targets
6546 can be overridden with @code{#:build-targets} and
6547 @code{#:install-targets} respectively. The version of Python used to
6548 run SCons can be specified by selecting the appropriate SCons package
6549 with the @code{#:scons} parameter.
6552 @defvr {Scheme Variable} haskell-build-system
6553 This variable is exported by @code{(guix build-system haskell)}. It
6554 implements the Cabal build procedure used by Haskell packages, which
6555 involves running @code{runhaskell Setup.hs configure
6556 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6557 Instead of installing the package by running @code{runhaskell Setup.hs
6558 install}, to avoid trying to register libraries in the read-only
6559 compiler store directory, the build system uses @code{runhaskell
6560 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6561 addition, the build system generates the package documentation by
6562 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6563 is passed. Optional Haddock parameters can be passed with the help of
6564 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6565 not found, the build system looks for @code{Setup.lhs} instead.
6567 Which Haskell compiler is used can be specified with the @code{#:haskell}
6568 parameter which defaults to @code{ghc}.
6571 @defvr {Scheme Variable} dub-build-system
6572 This variable is exported by @code{(guix build-system dub)}. It
6573 implements the Dub build procedure used by D packages, which
6574 involves running @code{dub build} and @code{dub run}.
6575 Installation is done by copying the files manually.
6577 Which D compiler is used can be specified with the @code{#:ldc}
6578 parameter which defaults to @code{ldc}.
6581 @defvr {Scheme Variable} emacs-build-system
6582 This variable is exported by @code{(guix build-system emacs)}. It
6583 implements an installation procedure similar to the packaging system
6584 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6586 It first creates the @code{@var{package}-autoloads.el} file, then it
6587 byte compiles all Emacs Lisp files. Differently from the Emacs
6588 packaging system, the Info documentation files are moved to the standard
6589 documentation directory and the @file{dir} file is deleted. Each
6590 package is installed in its own directory under
6591 @file{share/emacs/site-lisp/guix.d}.
6594 @defvr {Scheme Variable} font-build-system
6595 This variable is exported by @code{(guix build-system font)}. It
6596 implements an installation procedure for font packages where upstream
6597 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6598 need to be copied into place. It copies font files to standard
6599 locations in the output directory.
6602 @defvr {Scheme Variable} meson-build-system
6603 This variable is exported by @code{(guix build-system meson)}. It
6604 implements the build procedure for packages that use
6605 @url{https://mesonbuild.com, Meson} as their build system.
6607 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6608 of inputs, and they can be changed with the parameters @code{#:meson}
6609 and @code{#:ninja} if needed. The default Meson is
6610 @code{meson-for-build}, which is special because it doesn't clear the
6611 @code{RUNPATH} of binaries and libraries when they are installed.
6613 This build system is an extension of @var{gnu-build-system}, but with the
6614 following phases changed to some specific for Meson:
6619 The phase runs @code{meson} with the flags specified in
6620 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6621 @code{plain} unless something else is specified in @code{#:build-type}.
6624 The phase runs @code{ninja} to build the package in parallel by default, but
6625 this can be changed with @code{#:parallel-build?}.
6628 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6629 which is @code{"test"} by default.
6632 The phase runs @code{ninja install} and can not be changed.
6635 Apart from that, the build system also adds the following phases:
6640 This phase ensures that all binaries can find the libraries they need.
6641 It searches for required libraries in subdirectories of the package being
6642 built, and adds those to @code{RUNPATH} where needed. It also removes
6643 references to libraries left over from the build phase by
6644 @code{meson-for-build}, such as test dependencies, that aren't actually
6645 required for the program to run.
6647 @item glib-or-gtk-wrap
6648 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6649 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6651 @item glib-or-gtk-compile-schemas
6652 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6653 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6657 @defvr {Scheme Variable} linux-module-build-system
6658 @var{linux-module-build-system} allows building Linux kernel modules.
6660 @cindex build phases
6661 This build system is an extension of @var{gnu-build-system}, but with the
6662 following phases changed:
6667 This phase configures the environment so that the Linux kernel's Makefile
6668 can be used to build the external kernel module.
6671 This phase uses the Linux kernel's Makefile in order to build the external
6675 This phase uses the Linux kernel's Makefile in order to install the external
6679 It is possible and useful to specify the Linux kernel to use for building
6680 the module (in the "arguments" form of a package using the
6681 linux-module-build-system, use the key #:linux to specify it).
6684 @defvr {Scheme Variable} node-build-system
6685 This variable is exported by @code{(guix build-system node)}. It
6686 implements the build procedure used by @uref{http://nodejs.org,
6687 Node.js}, which implements an approximation of the @code{npm install}
6688 command, followed by an @code{npm test} command.
6690 Which Node.js package is used to interpret the @code{npm} commands can
6691 be specified with the @code{#:node} parameter which defaults to
6695 Lastly, for packages that do not need anything as sophisticated, a
6696 ``trivial'' build system is provided. It is trivial in the sense that
6697 it provides basically no support: it does not pull any implicit inputs,
6698 and does not have a notion of build phases.
6700 @defvr {Scheme Variable} trivial-build-system
6701 This variable is exported by @code{(guix build-system trivial)}.
6703 This build system requires a @code{#:builder} argument. This argument
6704 must be a Scheme expression that builds the package output(s)---as
6705 with @code{build-expression->derivation} (@pxref{Derivations,
6706 @code{build-expression->derivation}}).
6716 Conceptually, the @dfn{store} is the place where derivations that have
6717 been built successfully are stored---by default, @file{/gnu/store}.
6718 Sub-directories in the store are referred to as @dfn{store items} or
6719 sometimes @dfn{store paths}. The store has an associated database that
6720 contains information such as the store paths referred to by each store
6721 path, and the list of @emph{valid} store items---results of successful
6722 builds. This database resides in @file{@var{localstatedir}/guix/db},
6723 where @var{localstatedir} is the state directory specified @i{via}
6724 @option{--localstatedir} at configure time, usually @file{/var}.
6726 The store is @emph{always} accessed by the daemon on behalf of its clients
6727 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6728 connect to the daemon over a Unix-domain socket, send requests to it,
6729 and read the result---these are remote procedure calls, or RPCs.
6732 Users must @emph{never} modify files under @file{/gnu/store} directly.
6733 This would lead to inconsistencies and break the immutability
6734 assumptions of Guix's functional model (@pxref{Introduction}).
6736 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6737 how to check the integrity of the store and attempt recovery from
6738 accidental modifications.
6741 The @code{(guix store)} module provides procedures to connect to the
6742 daemon, and to perform RPCs. These are described below. By default,
6743 @code{open-connection}, and thus all the @command{guix} commands,
6744 connect to the local daemon or to the URI specified by the
6745 @code{GUIX_DAEMON_SOCKET} environment variable.
6747 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6748 When set, the value of this variable should be a file name or a URI
6749 designating the daemon endpoint. When it is a file name, it denotes a
6750 Unix-domain socket to connect to. In addition to file names, the
6751 supported URI schemes are:
6756 These are for Unix-domain sockets.
6757 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6758 @file{/var/guix/daemon-socket/socket}.
6761 @cindex daemon, remote access
6762 @cindex remote access to the daemon
6763 @cindex daemon, cluster setup
6764 @cindex clusters, daemon setup
6765 These URIs denote connections over TCP/IP, without encryption nor
6766 authentication of the remote host. The URI must specify the host name
6767 and optionally a port number (by default port 44146 is used):
6770 guix://master.guix.example.org:1234
6773 This setup is suitable on local networks, such as clusters, where only
6774 trusted nodes may connect to the build daemon at
6775 @code{master.guix.example.org}.
6777 The @code{--listen} option of @command{guix-daemon} can be used to
6778 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6782 @cindex SSH access to build daemons
6783 These URIs allow you to connect to a remote daemon over
6784 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6785 A typical URL might look like this:
6788 ssh://charlie@@guix.example.org:22
6791 As for @command{guix copy}, the usual OpenSSH client configuration files
6792 are honored (@pxref{Invoking guix copy}).
6795 Additional URI schemes may be supported in the future.
6797 @c XXX: Remove this note when the protocol incurs fewer round trips
6798 @c and when (guix derivations) no longer relies on file system access.
6800 The ability to connect to remote build daemons is considered
6801 experimental as of @value{VERSION}. Please get in touch with us to
6802 share any problems or suggestions you may have (@pxref{Contributing}).
6806 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6807 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6808 @var{reserve-space?} is true, instruct it to reserve a little bit of
6809 extra space on the file system so that the garbage collector can still
6810 operate should the disk become full. Return a server object.
6812 @var{file} defaults to @code{%default-socket-path}, which is the normal
6813 location given the options that were passed to @command{configure}.
6816 @deffn {Scheme Procedure} close-connection @var{server}
6817 Close the connection to @var{server}.
6820 @defvr {Scheme Variable} current-build-output-port
6821 This variable is bound to a SRFI-39 parameter, which refers to the port
6822 where build and error logs sent by the daemon should be written.
6825 Procedures that make RPCs all take a server object as their first
6828 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6829 @cindex invalid store items
6830 Return @code{#t} when @var{path} designates a valid store item and
6831 @code{#f} otherwise (an invalid item may exist on disk but still be
6832 invalid, for instance because it is the result of an aborted or failed
6835 A @code{&store-protocol-error} condition is raised if @var{path} is not
6836 prefixed by the store directory (@file{/gnu/store}).
6839 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6840 Add @var{text} under file @var{name} in the store, and return its store
6841 path. @var{references} is the list of store paths referred to by the
6842 resulting store path.
6845 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6847 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6848 file names, or derivation/output pairs, using the specified
6849 @var{mode}---@code{(build-mode normal)} by default.
6852 Note that the @code{(guix monads)} module provides a monad as well as
6853 monadic versions of the above procedures, with the goal of making it
6854 more convenient to work with code that accesses the store (@pxref{The
6858 @i{This section is currently incomplete.}
6861 @section Derivations
6864 Low-level build actions and the environment in which they are performed
6865 are represented by @dfn{derivations}. A derivation contains the
6866 following pieces of information:
6870 The outputs of the derivation---derivations produce at least one file or
6871 directory in the store, but may produce more.
6874 @cindex build-time dependencies
6875 @cindex dependencies, build-time
6876 The inputs of the derivations---i.e., its build-time dependencies---which may
6877 be other derivations or plain files in the store (patches, build scripts,
6881 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6884 The file name of a build script in the store, along with the arguments
6888 A list of environment variables to be defined.
6892 @cindex derivation path
6893 Derivations allow clients of the daemon to communicate build actions to
6894 the store. They exist in two forms: as an in-memory representation,
6895 both on the client- and daemon-side, and as files in the store whose
6896 name end in @code{.drv}---these files are referred to as @dfn{derivation
6897 paths}. Derivations paths can be passed to the @code{build-derivations}
6898 procedure to perform the build actions they prescribe (@pxref{The
6901 @cindex fixed-output derivations
6902 Operations such as file downloads and version-control checkouts for
6903 which the expected content hash is known in advance are modeled as
6904 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6905 of a fixed-output derivation are independent of its inputs---e.g., a
6906 source code download produces the same result regardless of the download
6907 method and tools being used.
6910 @cindex run-time dependencies
6911 @cindex dependencies, run-time
6912 The outputs of derivations---i.e., the build results---have a set of
6913 @dfn{references}, as reported by the @code{references} RPC or the
6914 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6915 are the set of run-time dependencies of the build results. References are a
6916 subset of the inputs of the derivation; this subset is automatically computed
6917 by the build daemon by scanning all the files in the outputs.
6919 The @code{(guix derivations)} module provides a representation of
6920 derivations as Scheme objects, along with procedures to create and
6921 otherwise manipulate derivations. The lowest-level primitive to create
6922 a derivation is the @code{derivation} procedure:
6924 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6925 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6926 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6927 [#:system (%current-system)] [#:references-graphs #f] @
6928 [#:allowed-references #f] [#:disallowed-references #f] @
6929 [#:leaked-env-vars #f] [#:local-build? #f] @
6930 [#:substitutable? #t] [#:properties '()]
6931 Build a derivation with the given arguments, and return the resulting
6932 @code{<derivation>} object.
6934 When @var{hash} and @var{hash-algo} are given, a
6935 @dfn{fixed-output derivation} is created---i.e., one whose result is
6936 known in advance, such as a file download. If, in addition,
6937 @var{recursive?} is true, then that fixed output may be an executable
6938 file or a directory and @var{hash} must be the hash of an archive
6939 containing this output.
6941 When @var{references-graphs} is true, it must be a list of file
6942 name/store path pairs. In that case, the reference graph of each store
6943 path is exported in the build environment in the corresponding file, in
6944 a simple text format.
6946 When @var{allowed-references} is true, it must be a list of store items
6947 or outputs that the derivation's output may refer to. Likewise,
6948 @var{disallowed-references}, if true, must be a list of things the
6949 outputs may @emph{not} refer to.
6951 When @var{leaked-env-vars} is true, it must be a list of strings
6952 denoting environment variables that are allowed to ``leak'' from the
6953 daemon's environment to the build environment. This is only applicable
6954 to fixed-output derivations---i.e., when @var{hash} is true. The main
6955 use is to allow variables such as @code{http_proxy} to be passed to
6956 derivations that download files.
6958 When @var{local-build?} is true, declare that the derivation is not a
6959 good candidate for offloading and should rather be built locally
6960 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6961 where the costs of data transfers would outweigh the benefits.
6963 When @var{substitutable?} is false, declare that substitutes of the
6964 derivation's output should not be used (@pxref{Substitutes}). This is
6965 useful, for instance, when building packages that capture details of the
6966 host CPU instruction set.
6968 @var{properties} must be an association list describing ``properties'' of the
6969 derivation. It is kept as-is, uninterpreted, in the derivation.
6973 Here's an example with a shell script as its builder, assuming
6974 @var{store} is an open connection to the daemon, and @var{bash} points
6975 to a Bash executable in the store:
6978 (use-modules (guix utils)
6982 (let ((builder ; add the Bash script to the store
6983 (add-text-to-store store "my-builder.sh"
6984 "echo hello world > $out\n" '())))
6985 (derivation store "foo"
6986 bash `("-e" ,builder)
6987 #:inputs `((,bash) (,builder))
6988 #:env-vars '(("HOME" . "/homeless"))))
6989 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6992 As can be guessed, this primitive is cumbersome to use directly. A
6993 better approach is to write build scripts in Scheme, of course! The
6994 best course of action for that is to write the build code as a
6995 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6996 information, @pxref{G-Expressions}.
6998 Once upon a time, @code{gexp->derivation} did not exist and constructing
6999 derivations with build code written in Scheme was achieved with
7000 @code{build-expression->derivation}, documented below. This procedure
7001 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7003 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7004 @var{name} @var{exp} @
7005 [#:system (%current-system)] [#:inputs '()] @
7006 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7007 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7008 [#:references-graphs #f] [#:allowed-references #f] @
7009 [#:disallowed-references #f] @
7010 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7011 Return a derivation that executes Scheme expression @var{exp} as a
7012 builder for derivation @var{name}. @var{inputs} must be a list of
7013 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7014 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7015 modules from the current search path to be copied in the store,
7016 compiled, and made available in the load path during the execution of
7017 @var{exp}---e.g., @code{((guix build utils) (guix build
7018 gnu-build-system))}.
7020 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7021 to a list of output/path pairs, and where @code{%build-inputs} is bound
7022 to a list of string/output-path pairs made from @var{inputs}.
7023 Optionally, @var{env-vars} is a list of string pairs specifying the name
7024 and value of environment variables visible to the builder. The builder
7025 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7026 @var{exp} returns @code{#f}, the build is considered to have failed.
7028 @var{exp} is built using @var{guile-for-build} (a derivation). When
7029 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7030 @code{%guile-for-build} fluid is used instead.
7032 See the @code{derivation} procedure for the meaning of
7033 @var{references-graphs}, @var{allowed-references},
7034 @var{disallowed-references}, @var{local-build?}, and
7035 @var{substitutable?}.
7039 Here's an example of a single-output derivation that creates a directory
7040 containing one file:
7043 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7044 (mkdir out) ; create /gnu/store/@dots{}-goo
7045 (call-with-output-file (string-append out "/test")
7047 (display '(hello guix) p))))))
7048 (build-expression->derivation store "goo" builder))
7050 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7054 @node The Store Monad
7055 @section The Store Monad
7059 The procedures that operate on the store described in the previous
7060 sections all take an open connection to the build daemon as their first
7061 argument. Although the underlying model is functional, they either have
7062 side effects or depend on the current state of the store.
7064 The former is inconvenient: the connection to the build daemon has to be
7065 carried around in all those functions, making it impossible to compose
7066 functions that do not take that parameter with functions that do. The
7067 latter can be problematic: since store operations have side effects
7068 and/or depend on external state, they have to be properly sequenced.
7070 @cindex monadic values
7071 @cindex monadic functions
7072 This is where the @code{(guix monads)} module comes in. This module
7073 provides a framework for working with @dfn{monads}, and a particularly
7074 useful monad for our uses, the @dfn{store monad}. Monads are a
7075 construct that allows two things: associating ``context'' with values
7076 (in our case, the context is the store), and building sequences of
7077 computations (here computations include accesses to the store). Values
7078 in a monad---values that carry this additional context---are called
7079 @dfn{monadic values}; procedures that return such values are called
7080 @dfn{monadic procedures}.
7082 Consider this ``normal'' procedure:
7085 (define (sh-symlink store)
7086 ;; Return a derivation that symlinks the 'bash' executable.
7087 (let* ((drv (package-derivation store bash))
7088 (out (derivation->output-path drv))
7089 (sh (string-append out "/bin/bash")))
7090 (build-expression->derivation store "sh"
7091 `(symlink ,sh %output))))
7094 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7095 as a monadic function:
7098 (define (sh-symlink)
7099 ;; Same, but return a monadic value.
7100 (mlet %store-monad ((drv (package->derivation bash)))
7101 (gexp->derivation "sh"
7102 #~(symlink (string-append #$drv "/bin/bash")
7106 There are several things to note in the second version: the @code{store}
7107 parameter is now implicit and is ``threaded'' in the calls to the
7108 @code{package->derivation} and @code{gexp->derivation} monadic
7109 procedures, and the monadic value returned by @code{package->derivation}
7110 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7112 As it turns out, the call to @code{package->derivation} can even be
7113 omitted since it will take place implicitly, as we will see later
7114 (@pxref{G-Expressions}):
7117 (define (sh-symlink)
7118 (gexp->derivation "sh"
7119 #~(symlink (string-append #$bash "/bin/bash")
7124 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7125 @c for the funny quote.
7126 Calling the monadic @code{sh-symlink} has no effect. As someone once
7127 said, ``you exit a monad like you exit a building on fire: by running''.
7128 So, to exit the monad and get the desired effect, one must use
7129 @code{run-with-store}:
7132 (run-with-store (open-connection) (sh-symlink))
7133 @result{} /gnu/store/...-sh-symlink
7136 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7137 new ``meta-commands'' to make it easier to deal with monadic procedures:
7138 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7139 to ``run'' a single monadic value through the store:
7142 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7143 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7146 The latter enters a recursive REPL, where all the return values are
7147 automatically run through the store:
7150 scheme@@(guile-user)> ,enter-store-monad
7151 store-monad@@(guile-user) [1]> (package->derivation hello)
7152 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7153 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7154 $3 = "/gnu/store/@dots{}-foo"
7155 store-monad@@(guile-user) [1]> ,q
7156 scheme@@(guile-user)>
7160 Note that non-monadic values cannot be returned in the
7161 @code{store-monad} REPL.
7163 The main syntactic forms to deal with monads in general are provided by
7164 the @code{(guix monads)} module and are described below.
7166 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7167 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7171 @deffn {Scheme Syntax} return @var{val}
7172 Return a monadic value that encapsulates @var{val}.
7175 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7176 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7177 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7178 referred to as ``bind'', but that name denotes an unrelated procedure in
7179 Guile. Thus we use this somewhat cryptic symbol inherited from the
7180 Haskell language.}. There can be one @var{mproc} or several of them, as
7185 (with-monad %state-monad
7187 (lambda (x) (return (+ 1 x)))
7188 (lambda (x) (return (* 2 x)))))
7192 @result{} some-state
7196 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7198 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7200 Bind the variables @var{var} to the monadic values @var{mval} in
7201 @var{body}, which is a sequence of expressions. As with the bind
7202 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7203 value ``contained'' in @var{mval} and making @var{var} refer to that
7204 raw, non-monadic value within the scope of the @var{body}. The form
7205 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7206 @var{val}, as per @code{let}. The binding operations occur in sequence
7207 from left to right. The last expression of @var{body} must be a monadic
7208 expression, and its result will become the result of the @code{mlet} or
7209 @code{mlet*} when run in the @var{monad}.
7211 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7212 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7215 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7216 Bind @var{mexp} and the following monadic expressions in sequence,
7217 returning the result of the last expression. Every expression in the
7218 sequence must be a monadic expression.
7220 This is akin to @code{mlet}, except that the return values of the
7221 monadic expressions are ignored. In that sense, it is analogous to
7222 @code{begin}, but applied to monadic expressions.
7225 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7226 When @var{condition} is true, evaluate the sequence of monadic
7227 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7228 @var{condition} is false, return @code{*unspecified*} in the current
7229 monad. Every expression in the sequence must be a monadic expression.
7232 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7233 When @var{condition} is false, evaluate the sequence of monadic
7234 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7235 @var{condition} is true, return @code{*unspecified*} in the current
7236 monad. Every expression in the sequence must be a monadic expression.
7240 The @code{(guix monads)} module provides the @dfn{state monad}, which
7241 allows an additional value---the state---to be @emph{threaded} through
7242 monadic procedure calls.
7244 @defvr {Scheme Variable} %state-monad
7245 The state monad. Procedures in the state monad can access and change
7246 the state that is threaded.
7248 Consider the example below. The @code{square} procedure returns a value
7249 in the state monad. It returns the square of its argument, but also
7250 increments the current state value:
7254 (mlet %state-monad ((count (current-state)))
7255 (mbegin %state-monad
7256 (set-current-state (+ 1 count))
7259 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7264 When ``run'' through @var{%state-monad}, we obtain that additional state
7265 value, which is the number of @code{square} calls.
7268 @deffn {Monadic Procedure} current-state
7269 Return the current state as a monadic value.
7272 @deffn {Monadic Procedure} set-current-state @var{value}
7273 Set the current state to @var{value} and return the previous state as a
7277 @deffn {Monadic Procedure} state-push @var{value}
7278 Push @var{value} to the current state, which is assumed to be a list,
7279 and return the previous state as a monadic value.
7282 @deffn {Monadic Procedure} state-pop
7283 Pop a value from the current state and return it as a monadic value.
7284 The state is assumed to be a list.
7287 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7288 Run monadic value @var{mval} starting with @var{state} as the initial
7289 state. Return two values: the resulting value, and the resulting state.
7292 The main interface to the store monad, provided by the @code{(guix
7293 store)} module, is as follows.
7295 @defvr {Scheme Variable} %store-monad
7296 The store monad---an alias for @var{%state-monad}.
7298 Values in the store monad encapsulate accesses to the store. When its
7299 effect is needed, a value of the store monad must be ``evaluated'' by
7300 passing it to the @code{run-with-store} procedure (see below.)
7303 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7304 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7305 open store connection.
7308 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7309 Return as a monadic value the absolute file name in the store of the file
7310 containing @var{text}, a string. @var{references} is a list of store items that the
7311 resulting text file refers to; it defaults to the empty list.
7314 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7315 Return as a monadic value the absolute file name in the store of the file
7316 containing @var{data}, a bytevector. @var{references} is a list of store
7317 items that the resulting binary file refers to; it defaults to the empty list.
7320 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7321 [#:recursive? #t] [#:select? (const #t)]
7322 Return the name of @var{file} once interned in the store. Use
7323 @var{name} as its store name, or the basename of @var{file} if
7324 @var{name} is omitted.
7326 When @var{recursive?} is true, the contents of @var{file} are added
7327 recursively; if @var{file} designates a flat file and @var{recursive?}
7328 is true, its contents are added, and its permission bits are kept.
7330 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7331 @var{stat})} for each directory entry, where @var{file} is the entry's
7332 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7333 entries for which @var{select?} does not return true.
7335 The example below adds a file to the store, under two different names:
7338 (run-with-store (open-connection)
7339 (mlet %store-monad ((a (interned-file "README"))
7340 (b (interned-file "README" "LEGU-MIN")))
7341 (return (list a b))))
7343 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7348 The @code{(guix packages)} module exports the following package-related
7351 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7352 [#:system (%current-system)] [#:target #f] @
7355 value in the absolute file name of @var{file} within the @var{output}
7356 directory of @var{package}. When @var{file} is omitted, return the name
7357 of the @var{output} directory of @var{package}. When @var{target} is
7358 true, use it as a cross-compilation target triplet.
7361 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7362 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7363 @var{target} [@var{system}]
7364 Monadic version of @code{package-derivation} and
7365 @code{package-cross-derivation} (@pxref{Defining Packages}).
7370 @section G-Expressions
7372 @cindex G-expression
7373 @cindex build code quoting
7374 So we have ``derivations'', which represent a sequence of build actions
7375 to be performed to produce an item in the store (@pxref{Derivations}).
7376 These build actions are performed when asking the daemon to actually
7377 build the derivations; they are run by the daemon in a container
7378 (@pxref{Invoking guix-daemon}).
7380 @cindex strata of code
7381 It should come as no surprise that we like to write these build actions
7382 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7383 code@footnote{The term @dfn{stratum} in this context was coined by
7384 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7385 Kiselyov, who has written insightful
7386 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7387 on this topic}, refers to this kind of code generation as
7388 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7389 to the daemon, etc.---and the ``build code''---code that actually
7390 performs build actions, such as making directories, invoking
7391 @command{make}, etc.
7393 To describe a derivation and its build actions, one typically needs to
7394 embed build code inside host code. It boils down to manipulating build
7395 code as data, and the homoiconicity of Scheme---code has a direct
7396 representation as data---comes in handy for that. But we need more than
7397 the normal @code{quasiquote} mechanism in Scheme to construct build
7400 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7401 S-expressions adapted to build expressions. G-expressions, or
7402 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7403 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7404 @code{#$}, and @code{#$@@}), which are comparable to
7405 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7406 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7407 GNU Guile Reference Manual}). However, there are major differences:
7411 Gexps are meant to be written to a file and run or manipulated by other
7415 When a high-level object such as a package or derivation is unquoted
7416 inside a gexp, the result is as if its output file name had been
7420 Gexps carry information about the packages or derivations they refer to,
7421 and these dependencies are automatically added as inputs to the build
7422 processes that use them.
7425 @cindex lowering, of high-level objects in gexps
7426 This mechanism is not limited to package and derivation
7427 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7428 derivations or files in the store can be defined,
7429 such that these objects can also be inserted
7430 into gexps. For example, a useful type of high-level objects that can be
7431 inserted in a gexp is ``file-like objects'', which make it easy to
7432 add files to the store and to refer to them in
7433 derivations and such (see @code{local-file} and @code{plain-file}
7436 To illustrate the idea, here is an example of a gexp:
7443 (symlink (string-append #$coreutils "/bin/ls")
7447 This gexp can be passed to @code{gexp->derivation}; we obtain a
7448 derivation that builds a directory containing exactly one symlink to
7449 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7452 (gexp->derivation "the-thing" build-exp)
7455 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7456 substituted to the reference to the @var{coreutils} package in the
7457 actual build code, and @var{coreutils} is automatically made an input to
7458 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7459 output)}) is replaced by a string containing the directory name of the
7460 output of the derivation.
7462 @cindex cross compilation
7463 In a cross-compilation context, it is useful to distinguish between
7464 references to the @emph{native} build of a package---that can run on the
7465 host---versus references to cross builds of a package. To that end, the
7466 @code{#+} plays the same role as @code{#$}, but is a reference to a
7467 native package build:
7470 (gexp->derivation "vi"
7473 (mkdir (string-append #$output "/bin"))
7474 (system* (string-append #+coreutils "/bin/ln")
7476 (string-append #$emacs "/bin/emacs")
7477 (string-append #$output "/bin/vi")))
7478 #:target "mips64el-linux-gnu")
7482 In the example above, the native build of @var{coreutils} is used, so
7483 that @command{ln} can actually run on the host; but then the
7484 cross-compiled build of @var{emacs} is referenced.
7486 @cindex imported modules, for gexps
7487 @findex with-imported-modules
7488 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7489 able to use certain Guile modules from the ``host environment'' in the
7490 gexp, so those modules should be imported in the ``build environment''.
7491 The @code{with-imported-modules} form allows you to express that:
7494 (let ((build (with-imported-modules '((guix build utils))
7496 (use-modules (guix build utils))
7497 (mkdir-p (string-append #$output "/bin"))))))
7498 (gexp->derivation "empty-dir"
7501 (display "success!\n")
7506 In this example, the @code{(guix build utils)} module is automatically
7507 pulled into the isolated build environment of our gexp, such that
7508 @code{(use-modules (guix build utils))} works as expected.
7510 @cindex module closure
7511 @findex source-module-closure
7512 Usually you want the @emph{closure} of the module to be imported---i.e.,
7513 the module itself and all the modules it depends on---rather than just
7514 the module; failing to do that, attempts to use the module will fail
7515 because of missing dependent modules. The @code{source-module-closure}
7516 procedure computes the closure of a module by looking at its source file
7517 headers, which comes in handy in this case:
7520 (use-modules (guix modules)) ;for 'source-module-closure'
7522 (with-imported-modules (source-module-closure
7523 '((guix build utils)
7525 (gexp->derivation "something-with-vms"
7527 (use-modules (guix build utils)
7532 @cindex extensions, for gexps
7533 @findex with-extensions
7534 In the same vein, sometimes you want to import not just pure-Scheme
7535 modules, but also ``extensions'' such as Guile bindings to C libraries
7536 or other ``full-blown'' packages. Say you need the @code{guile-json}
7537 package available on the build side, here's how you would do it:
7540 (use-modules (gnu packages guile)) ;for 'guile-json'
7542 (with-extensions (list guile-json)
7543 (gexp->derivation "something-with-json"
7545 (use-modules (json))
7549 The syntactic form to construct gexps is summarized below.
7551 @deffn {Scheme Syntax} #~@var{exp}
7552 @deffnx {Scheme Syntax} (gexp @var{exp})
7553 Return a G-expression containing @var{exp}. @var{exp} may contain one
7554 or more of the following forms:
7558 @itemx (ungexp @var{obj})
7559 Introduce a reference to @var{obj}. @var{obj} may have one of the
7560 supported types, for example a package or a
7561 derivation, in which case the @code{ungexp} form is replaced by its
7562 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7564 If @var{obj} is a list, it is traversed and references to supported
7565 objects are substituted similarly.
7567 If @var{obj} is another gexp, its contents are inserted and its
7568 dependencies are added to those of the containing gexp.
7570 If @var{obj} is another kind of object, it is inserted as is.
7572 @item #$@var{obj}:@var{output}
7573 @itemx (ungexp @var{obj} @var{output})
7574 This is like the form above, but referring explicitly to the
7575 @var{output} of @var{obj}---this is useful when @var{obj} produces
7576 multiple outputs (@pxref{Packages with Multiple Outputs}).
7579 @itemx #+@var{obj}:output
7580 @itemx (ungexp-native @var{obj})
7581 @itemx (ungexp-native @var{obj} @var{output})
7582 Same as @code{ungexp}, but produces a reference to the @emph{native}
7583 build of @var{obj} when used in a cross compilation context.
7585 @item #$output[:@var{output}]
7586 @itemx (ungexp output [@var{output}])
7587 Insert a reference to derivation output @var{output}, or to the main
7588 output when @var{output} is omitted.
7590 This only makes sense for gexps passed to @code{gexp->derivation}.
7593 @itemx (ungexp-splicing @var{lst})
7594 Like the above, but splices the contents of @var{lst} inside the
7598 @itemx (ungexp-native-splicing @var{lst})
7599 Like the above, but refers to native builds of the objects listed in
7604 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7605 of the @code{gexp?} type (see below.)
7608 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7609 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7610 in their execution environment.
7612 Each item in @var{modules} can be the name of a module, such as
7613 @code{(guix build utils)}, or it can be a module name, followed by an
7614 arrow, followed by a file-like object:
7617 `((guix build utils)
7619 ((guix config) => ,(scheme-file "config.scm"
7620 #~(define-module @dots{}))))
7624 In the example above, the first two modules are taken from the search
7625 path, and the last one is created from the given file-like object.
7627 This form has @emph{lexical} scope: it has an effect on the gexps
7628 directly defined in @var{body}@dots{}, but not on those defined, say, in
7629 procedures called from @var{body}@dots{}.
7632 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7633 Mark the gexps defined in @var{body}@dots{} as requiring
7634 @var{extensions} in their build and execution environment.
7635 @var{extensions} is typically a list of package objects such as those
7636 defined in the @code{(gnu packages guile)} module.
7638 Concretely, the packages listed in @var{extensions} are added to the
7639 load path while compiling imported modules in @var{body}@dots{}; they
7640 are also added to the load path of the gexp returned by
7644 @deffn {Scheme Procedure} gexp? @var{obj}
7645 Return @code{#t} if @var{obj} is a G-expression.
7648 G-expressions are meant to be written to disk, either as code building
7649 some derivation, or as plain files in the store. The monadic procedures
7650 below allow you to do that (@pxref{The Store Monad}, for more
7651 information about monads.)
7653 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7654 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7655 [#:hash #f] [#:hash-algo #f] @
7656 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7657 [#:module-path @var{%load-path}] @
7658 [#:effective-version "2.2"] @
7659 [#:references-graphs #f] [#:allowed-references #f] @
7660 [#:disallowed-references #f] @
7661 [#:leaked-env-vars #f] @
7662 [#:script-name (string-append @var{name} "-builder")] @
7663 [#:deprecation-warnings #f] @
7664 [#:local-build? #f] [#:substitutable? #t] @
7665 [#:properties '()] [#:guile-for-build #f]
7666 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7667 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7668 stored in a file called @var{script-name}. When @var{target} is true,
7669 it is used as the cross-compilation target triplet for packages referred
7672 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7674 make @var{modules} available in the evaluation context of @var{exp};
7675 @var{modules} is a list of names of Guile modules searched in
7676 @var{module-path} to be copied in the store, compiled, and made available in
7677 the load path during the execution of @var{exp}---e.g., @code{((guix
7678 build utils) (guix build gnu-build-system))}.
7680 @var{effective-version} determines the string to use when adding extensions of
7681 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7683 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7686 When @var{references-graphs} is true, it must be a list of tuples of one of the
7690 (@var{file-name} @var{package})
7691 (@var{file-name} @var{package} @var{output})
7692 (@var{file-name} @var{derivation})
7693 (@var{file-name} @var{derivation} @var{output})
7694 (@var{file-name} @var{store-item})
7697 The right-hand-side of each element of @var{references-graphs} is automatically made
7698 an input of the build process of @var{exp}. In the build environment, each
7699 @var{file-name} contains the reference graph of the corresponding item, in a simple
7702 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7703 In the latter case, the list denotes store items that the result is allowed to
7704 refer to. Any reference to another store item will lead to a build error.
7705 Similarly for @var{disallowed-references}, which can list items that must not be
7706 referenced by the outputs.
7708 @var{deprecation-warnings} determines whether to show deprecation warnings while
7709 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7711 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7714 @cindex file-like objects
7715 The @code{local-file}, @code{plain-file}, @code{computed-file},
7716 @code{program-file}, and @code{scheme-file} procedures below return
7717 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7718 these objects lead to a file in the store. Consider this G-expression:
7721 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7722 #$(local-file "/tmp/my-nscd.conf"))
7725 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7726 to the store. Once expanded, for instance @i{via}
7727 @code{gexp->derivation}, the G-expression refers to that copy under
7728 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7729 does not have any effect on what the G-expression does.
7730 @code{plain-file} can be used similarly; it differs in that the file
7731 content is directly passed as a string.
7733 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7734 [#:recursive? #f] [#:select? (const #t)]
7735 Return an object representing local file @var{file} to add to the store;
7736 this object can be used in a gexp. If @var{file} is a literal string
7737 denoting a relative file name, it is looked up relative to the source
7738 file where it appears; if @var{file} is not a literal string, it is
7739 looked up relative to the current working directory at run time.
7740 @var{file} will be added to the store under @var{name}--by default the
7741 base name of @var{file}.
7743 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7744 designates a flat file and @var{recursive?} is true, its contents are added, and its
7745 permission bits are kept.
7747 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7748 @var{stat})} for each directory entry, where @var{file} is the entry's
7749 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7750 entries for which @var{select?} does not return true.
7752 This is the declarative counterpart of the @code{interned-file} monadic
7753 procedure (@pxref{The Store Monad, @code{interned-file}}).
7756 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7757 Return an object representing a text file called @var{name} with the given
7758 @var{content} (a string or a bytevector) to be added to the store.
7760 This is the declarative counterpart of @code{text-file}.
7763 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7764 [#:options '(#:local-build? #t)]
7765 Return an object representing the store item @var{name}, a file or
7766 directory computed by @var{gexp}. @var{options}
7767 is a list of additional arguments to pass to @code{gexp->derivation}.
7769 This is the declarative counterpart of @code{gexp->derivation}.
7772 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7773 [#:guile (default-guile)] [#:module-path %load-path] @
7774 [#:system (%current-system)] [#:target #f]
7775 Return an executable script @var{name} that runs @var{exp} using
7776 @var{guile}, with @var{exp}'s imported modules in its search path.
7777 Look up @var{exp}'s modules in @var{module-path}.
7779 The example below builds a script that simply invokes the @command{ls}
7783 (use-modules (guix gexp) (gnu packages base))
7785 (gexp->script "list-files"
7786 #~(execl #$(file-append coreutils "/bin/ls")
7790 When ``running'' it through the store (@pxref{The Store Monad,
7791 @code{run-with-store}}), we obtain a derivation that produces an
7792 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7795 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7797 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7801 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7802 [#:guile #f] [#:module-path %load-path]
7803 Return an object representing the executable store item @var{name} that
7804 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7805 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7807 This is the declarative counterpart of @code{gexp->script}.
7810 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7811 [#:set-load-path? #t] [#:module-path %load-path] @
7813 [#:guile (default-guile)]
7814 Return a derivation that builds a file @var{name} containing @var{exp}.
7815 When @var{splice?} is true, @var{exp} is considered to be a list of
7816 expressions that will be spliced in the resulting file.
7818 When @var{set-load-path?} is true, emit code in the resulting file to
7819 set @code{%load-path} and @code{%load-compiled-path} to honor
7820 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7823 The resulting file holds references to all the dependencies of @var{exp}
7824 or a subset thereof.
7827 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7828 Return an object representing the Scheme file @var{name} that contains
7831 This is the declarative counterpart of @code{gexp->file}.
7834 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7835 Return as a monadic value a derivation that builds a text file
7836 containing all of @var{text}. @var{text} may list, in addition to
7837 strings, objects of any type that can be used in a gexp: packages,
7838 derivations, local file objects, etc. The resulting store file holds
7839 references to all these.
7841 This variant should be preferred over @code{text-file} anytime the file
7842 to create will reference items from the store. This is typically the
7843 case when building a configuration file that embeds store file names,
7847 (define (profile.sh)
7848 ;; Return the name of a shell script in the store that
7849 ;; initializes the 'PATH' environment variable.
7850 (text-file* "profile.sh"
7851 "export PATH=" coreutils "/bin:"
7852 grep "/bin:" sed "/bin\n"))
7855 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7856 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7857 preventing them from being garbage-collected during its lifetime.
7860 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7861 Return an object representing store file @var{name} containing
7862 @var{text}. @var{text} is a sequence of strings and file-like objects,
7866 (mixed-text-file "profile"
7867 "export PATH=" coreutils "/bin:" grep "/bin")
7870 This is the declarative counterpart of @code{text-file*}.
7873 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7874 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7875 Each item in @var{files} must be a two-element list where the first element is the
7876 file name to use in the new directory, and the second element is a gexp
7877 denoting the target file. Here's an example:
7881 `(("hosts" ,(plain-file "hosts"
7882 "127.0.0.1 localhost"))
7883 ("bashrc" ,(plain-file "bashrc"
7884 "alias ls='ls --color=auto'"))))
7887 This yields an @code{etc} directory containing these two files.
7890 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7891 Return a directory that is the union of @var{things}, where @var{things} is a list of
7892 file-like objects denoting directories. For example:
7895 (directory-union "guile+emacs" (list guile emacs))
7898 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7901 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7902 Return a file-like object that expands to the concatenation of @var{obj}
7903 and @var{suffix}, where @var{obj} is a lowerable object and each
7904 @var{suffix} is a string.
7906 As an example, consider this gexp:
7909 (gexp->script "run-uname"
7910 #~(system* #$(file-append coreutils
7914 The same effect could be achieved with:
7917 (gexp->script "run-uname"
7918 #~(system* (string-append #$coreutils
7922 There is one difference though: in the @code{file-append} case, the
7923 resulting script contains the absolute file name as a string, whereas in
7924 the second case, the resulting script contains a @code{(string-append
7925 @dots{})} expression to construct the file name @emph{at run time}.
7929 Of course, in addition to gexps embedded in ``host'' code, there are
7930 also modules containing build tools. To make it clear that they are
7931 meant to be used in the build stratum, these modules are kept in the
7932 @code{(guix build @dots{})} name space.
7934 @cindex lowering, of high-level objects in gexps
7935 Internally, high-level objects are @dfn{lowered}, using their compiler,
7936 to either derivations or store items. For instance, lowering a package
7937 yields a derivation, and lowering a @code{plain-file} yields a store
7938 item. This is achieved using the @code{lower-object} monadic procedure.
7940 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7942 Return as a value in @var{%store-monad} the derivation or store item
7943 corresponding to @var{obj} for @var{system}, cross-compiling for
7944 @var{target} if @var{target} is true. @var{obj} must be an object that
7945 has an associated gexp compiler, such as a @code{<package>}.
7948 @node Invoking guix repl
7949 @section Invoking @command{guix repl}
7951 @cindex REPL, read-eval-print loop
7952 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7953 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7954 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7955 command, @command{guix repl} guarantees that all the Guix modules and all its
7956 dependencies are available in the search path. You can use it this way:
7960 scheme@@(guile-user)> ,use (gnu packages base)
7961 scheme@@(guile-user)> coreutils
7962 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7966 In addition, @command{guix repl} implements a simple machine-readable REPL
7967 protocol for use by @code{(guix inferior)}, a facility to interact with
7968 @dfn{inferiors}, separate processes running a potentially different revision
7971 The available options are as follows:
7974 @item --type=@var{type}
7975 @itemx -t @var{type}
7976 Start a REPL of the given @var{TYPE}, which can be one of the following:
7980 This is default, and it spawns a standard full-featured Guile REPL.
7982 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7983 that the @code{(guix inferior)} module speaks.
7986 @item --listen=@var{endpoint}
7987 By default, @command{guix repl} reads from standard input and writes to
7988 standard output. When this option is passed, it will instead listen for
7989 connections on @var{endpoint}. Here are examples of valid options:
7992 @item --listen=tcp:37146
7993 Accept connections on localhost on port 37146.
7995 @item --listen=unix:/tmp/socket
7996 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8000 @c *********************************************************************
8004 This section describes Guix command-line utilities. Some of them are
8005 primarily targeted at developers and users who write new package
8006 definitions, while others are more generally useful. They complement
8007 the Scheme programming interface of Guix in a convenient way.
8010 * Invoking guix build:: Building packages from the command line.
8011 * Invoking guix edit:: Editing package definitions.
8012 * Invoking guix download:: Downloading a file and printing its hash.
8013 * Invoking guix hash:: Computing the cryptographic hash of a file.
8014 * Invoking guix import:: Importing package definitions.
8015 * Invoking guix refresh:: Updating package definitions.
8016 * Invoking guix lint:: Finding errors in package definitions.
8017 * Invoking guix size:: Profiling disk usage.
8018 * Invoking guix graph:: Visualizing the graph of packages.
8019 * Invoking guix publish:: Sharing substitutes.
8020 * Invoking guix challenge:: Challenging substitute servers.
8021 * Invoking guix copy:: Copying to and from a remote store.
8022 * Invoking guix container:: Process isolation.
8023 * Invoking guix weather:: Assessing substitute availability.
8024 * Invoking guix processes:: Listing client processes.
8027 @node Invoking guix build
8028 @section Invoking @command{guix build}
8030 @cindex package building
8031 @cindex @command{guix build}
8032 The @command{guix build} command builds packages or derivations and
8033 their dependencies, and prints the resulting store paths. Note that it
8034 does not modify the user's profile---this is the job of the
8035 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8036 it is mainly useful for distribution developers.
8038 The general syntax is:
8041 guix build @var{options} @var{package-or-derivation}@dots{}
8044 As an example, the following command builds the latest versions of Emacs
8045 and of Guile, displays their build logs, and finally displays the
8046 resulting directories:
8049 guix build emacs guile
8052 Similarly, the following command builds all the available packages:
8055 guix build --quiet --keep-going \
8056 `guix package -A | cut -f1,2 --output-delimiter=@@`
8059 @var{package-or-derivation} may be either the name of a package found in
8060 the software distribution such as @code{coreutils} or
8061 @code{coreutils@@8.20}, or a derivation such as
8062 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8063 package with the corresponding name (and optionally version) is searched
8064 for among the GNU distribution modules (@pxref{Package Modules}).
8066 Alternatively, the @code{--expression} option may be used to specify a
8067 Scheme expression that evaluates to a package; this is useful when
8068 disambiguating among several same-named packages or package variants is
8071 There may be zero or more @var{options}. The available options are
8072 described in the subsections below.
8075 * Common Build Options:: Build options for most commands.
8076 * Package Transformation Options:: Creating variants of packages.
8077 * Additional Build Options:: Options specific to 'guix build'.
8078 * Debugging Build Failures:: Real life packaging experience.
8081 @node Common Build Options
8082 @subsection Common Build Options
8084 A number of options that control the build process are common to
8085 @command{guix build} and other commands that can spawn builds, such as
8086 @command{guix package} or @command{guix archive}. These are the
8091 @item --load-path=@var{directory}
8092 @itemx -L @var{directory}
8093 Add @var{directory} to the front of the package module search path
8094 (@pxref{Package Modules}).
8096 This allows users to define their own packages and make them visible to
8097 the command-line tools.
8101 Keep the build tree of failed builds. Thus, if a build fails, its build
8102 tree is kept under @file{/tmp}, in a directory whose name is shown at
8103 the end of the build log. This is useful when debugging build issues.
8104 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8107 This option implies @option{--no-offload}, and it has no effect when
8108 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8109 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8113 Keep going when some of the derivations fail to build; return only once
8114 all the builds have either completed or failed.
8116 The default behavior is to stop as soon as one of the specified
8117 derivations has failed.
8121 Do not build the derivations.
8123 @anchor{fallback-option}
8125 When substituting a pre-built binary fails, fall back to building
8126 packages locally (@pxref{Substitution Failure}).
8128 @item --substitute-urls=@var{urls}
8129 @anchor{client-substitute-urls}
8130 Consider @var{urls} the whitespace-separated list of substitute source
8131 URLs, overriding the default list of URLs of @command{guix-daemon}
8132 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8134 This means that substitutes may be downloaded from @var{urls}, provided
8135 they are signed by a key authorized by the system administrator
8136 (@pxref{Substitutes}).
8138 When @var{urls} is the empty string, substitutes are effectively
8141 @item --no-substitutes
8142 Do not use substitutes for build products. That is, always build things
8143 locally instead of allowing downloads of pre-built binaries
8144 (@pxref{Substitutes}).
8147 Do not ``graft'' packages. In practice, this means that package updates
8148 available as grafts are not applied. @xref{Security Updates}, for more
8149 information on grafts.
8151 @item --rounds=@var{n}
8152 Build each derivation @var{n} times in a row, and raise an error if
8153 consecutive build results are not bit-for-bit identical.
8155 This is a useful way to detect non-deterministic builds processes.
8156 Non-deterministic build processes are a problem because they make it
8157 practically impossible for users to @emph{verify} whether third-party
8158 binaries are genuine. @xref{Invoking guix challenge}, for more.
8160 Note that, currently, the differing build results are not kept around,
8161 so you will have to manually investigate in case of an error---e.g., by
8162 stashing one of the build results with @code{guix archive --export}
8163 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8167 Do not use offload builds to other machines (@pxref{Daemon Offload
8168 Setup}). That is, always build things locally instead of offloading
8169 builds to remote machines.
8171 @item --max-silent-time=@var{seconds}
8172 When the build or substitution process remains silent for more than
8173 @var{seconds}, terminate it and report a build failure.
8175 By default, the daemon's setting is honored (@pxref{Invoking
8176 guix-daemon, @code{--max-silent-time}}).
8178 @item --timeout=@var{seconds}
8179 Likewise, when the build or substitution process lasts for more than
8180 @var{seconds}, terminate it and report a build failure.
8182 By default, the daemon's setting is honored (@pxref{Invoking
8183 guix-daemon, @code{--timeout}}).
8185 @c Note: This option is actually not part of %standard-build-options but
8186 @c most programs honor it.
8187 @cindex verbosity, of the command-line tools
8188 @cindex build logs, verbosity
8189 @item -v @var{level}
8190 @itemx --verbosity=@var{level}
8191 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8192 output is produced, 1 is for quiet output, and 2 shows all the build log
8193 output on standard error.
8195 @item --cores=@var{n}
8197 Allow the use of up to @var{n} CPU cores for the build. The special
8198 value @code{0} means to use as many CPU cores as available.
8200 @item --max-jobs=@var{n}
8202 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8203 guix-daemon, @code{--max-jobs}}, for details about this option and the
8204 equivalent @command{guix-daemon} option.
8206 @item --debug=@var{level}
8207 Produce debugging output coming from the build daemon. @var{level} must be an
8208 integer between 0 and 5; higher means more verbose output. Setting a level of
8209 4 or more may be helpful when debugging setup issues with the build daemon.
8213 Behind the scenes, @command{guix build} is essentially an interface to
8214 the @code{package-derivation} procedure of the @code{(guix packages)}
8215 module, and to the @code{build-derivations} procedure of the @code{(guix
8216 derivations)} module.
8218 In addition to options explicitly passed on the command line,
8219 @command{guix build} and other @command{guix} commands that support
8220 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8222 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8223 Users can define this variable to a list of command line options that
8224 will automatically be used by @command{guix build} and other
8225 @command{guix} commands that can perform builds, as in the example
8229 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8232 These options are parsed independently, and the result is appended to
8233 the parsed command-line options.
8237 @node Package Transformation Options
8238 @subsection Package Transformation Options
8240 @cindex package variants
8241 Another set of command-line options supported by @command{guix build}
8242 and also @command{guix package} are @dfn{package transformation
8243 options}. These are options that make it possible to define @dfn{package
8244 variants}---for instance, packages built from different source code.
8245 This is a convenient way to create customized packages on the fly
8246 without having to type in the definitions of package variants
8247 (@pxref{Defining Packages}).
8251 @item --with-source=@var{source}
8252 @itemx --with-source=@var{package}=@var{source}
8253 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8254 Use @var{source} as the source of @var{package}, and @var{version} as
8256 @var{source} must be a file name or a URL, as for @command{guix
8257 download} (@pxref{Invoking guix download}).
8259 When @var{package} is omitted,
8260 it is taken to be the package name specified on the
8261 command line that matches the base of @var{source}---e.g.,
8262 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8263 package is @code{guile}.
8265 Likewise, when @var{version} is omitted, the version string is inferred from
8266 @var{source}; in the previous example, it is @code{2.0.10}.
8268 This option allows users to try out versions of packages other than the
8269 one provided by the distribution. The example below downloads
8270 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8271 the @code{ed} package:
8274 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8277 As a developer, @code{--with-source} makes it easy to test release
8281 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8284 @dots{} or to build from a checkout in a pristine environment:
8287 $ git clone git://git.sv.gnu.org/guix.git
8288 $ guix build guix --with-source=guix@@1.0=./guix
8291 @item --with-input=@var{package}=@var{replacement}
8292 Replace dependency on @var{package} by a dependency on
8293 @var{replacement}. @var{package} must be a package name, and
8294 @var{replacement} must be a package specification such as @code{guile}
8295 or @code{guile@@1.8}.
8297 For instance, the following command builds Guix, but replaces its
8298 dependency on the current stable version of Guile with a dependency on
8299 the legacy version of Guile, @code{guile@@2.0}:
8302 guix build --with-input=guile=guile@@2.0 guix
8305 This is a recursive, deep replacement. So in this example, both
8306 @code{guix} and its dependency @code{guile-json} (which also depends on
8307 @code{guile}) get rebuilt against @code{guile@@2.0}.
8309 This is implemented using the @code{package-input-rewriting} Scheme
8310 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8312 @item --with-graft=@var{package}=@var{replacement}
8313 This is similar to @code{--with-input} but with an important difference:
8314 instead of rebuilding the whole dependency chain, @var{replacement} is
8315 built and then @dfn{grafted} onto the binaries that were initially
8316 referring to @var{package}. @xref{Security Updates}, for more
8317 information on grafts.
8319 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8320 and all its dependencies, replacing references to the version of GnuTLS
8321 they currently refer to:
8324 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8327 This has the advantage of being much faster than rebuilding everything.
8328 But there is a caveat: it works if and only if @var{package} and
8329 @var{replacement} are strictly compatible---for example, if they provide
8330 a library, the application binary interface (ABI) of those libraries
8331 must be compatible. If @var{replacement} is somehow incompatible with
8332 @var{package}, then the resulting package may be unusable. Use with
8335 @item --with-git-url=@var{package}=@var{url}
8336 @cindex Git, using the latest commit
8337 @cindex latest commit, building
8338 Build @var{package} from the latest commit of the @code{master} branch of the
8339 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8342 For example, the following command builds the NumPy Python library against the
8343 latest commit of the master branch of Python itself:
8346 guix build python-numpy \
8347 --with-git-url=python=https://github.com/python/cpython
8350 This option can also be combined with @code{--with-branch} or
8351 @code{--with-commit} (see below).
8353 @cindex continuous integration
8354 Obviously, since it uses the latest commit of the given branch, the result of
8355 such a command varies over time. Nevertheless it is a convenient way to
8356 rebuild entire software stacks against the latest commit of one or more
8357 packages. This is particularly useful in the context of continuous
8360 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8361 consecutive accesses to the same repository. You may want to clean it up once
8362 in a while to save disk space.
8364 @item --with-branch=@var{package}=@var{branch}
8365 Build @var{package} from the latest commit of @var{branch}. If the
8366 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8367 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8368 repository URL is taken from that @code{source}. Otherwise you have to use
8369 @code{--with-git-url} to specify the URL of the Git repository.
8371 For instance, the following command builds @code{guile-sqlite3} from the
8372 latest commit of its @code{master} branch, and then builds @code{guix} (which
8373 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8374 specific @code{guile-sqlite3} build:
8377 guix build --with-branch=guile-sqlite3=master cuirass
8380 @item --with-commit=@var{package}=@var{commit}
8381 This is similar to @code{--with-branch}, except that it builds from
8382 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8383 Git commit SHA1 identifier or a tag.
8386 @node Additional Build Options
8387 @subsection Additional Build Options
8389 The command-line options presented below are specific to @command{guix
8396 Build quietly, without displaying the build log; this is equivalent to
8397 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8398 (or similar) and can always be retrieved using the @option{--log-file} option.
8400 @item --file=@var{file}
8401 @itemx -f @var{file}
8402 Build the package, derivation, or other file-like object that the code within
8403 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8405 As an example, @var{file} might contain a package definition like this
8406 (@pxref{Defining Packages}):
8409 @include package-hello.scm
8412 @item --expression=@var{expr}
8413 @itemx -e @var{expr}
8414 Build the package or derivation @var{expr} evaluates to.
8416 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8417 guile-1.8)}, which unambiguously designates this specific variant of
8418 version 1.8 of Guile.
8420 Alternatively, @var{expr} may be a G-expression, in which case it is used
8421 as a build program passed to @code{gexp->derivation}
8422 (@pxref{G-Expressions}).
8424 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8425 (@pxref{The Store Monad}). The procedure must return a derivation as a
8426 monadic value, which is then passed through @code{run-with-store}.
8430 Build the source derivations of the packages, rather than the packages
8433 For instance, @code{guix build -S gcc} returns something like
8434 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8437 The returned source tarball is the result of applying any patches and
8438 code snippets specified in the package @code{origin} (@pxref{Defining
8441 Note that @command{guix build -S} compiles the sources only of the
8442 specified packages. They do not include the sources of statically
8443 linked dependencies and by themselves are insufficient for reproducing
8447 Fetch and return the source of @var{package-or-derivation} and all their
8448 dependencies, recursively. This is a handy way to obtain a local copy
8449 of all the source code needed to build @var{packages}, allowing you to
8450 eventually build them even without network access. It is an extension
8451 of the @code{--source} option and can accept one of the following
8452 optional argument values:
8456 This value causes the @code{--sources} option to behave in the same way
8457 as the @code{--source} option.
8460 Build the source derivations of all packages, including any source that
8461 might be listed as @code{inputs}. This is the default value.
8464 $ guix build --sources tzdata
8465 The following derivations will be built:
8466 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8467 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8471 Build the source derivations of all packages, as well of all transitive
8472 inputs to the packages. This can be used e.g.@: to
8473 prefetch package source for later offline building.
8476 $ guix build --sources=transitive tzdata
8477 The following derivations will be built:
8478 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8479 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8480 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8481 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8482 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8483 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8489 @item --system=@var{system}
8490 @itemx -s @var{system}
8491 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8492 the system type of the build host. The @command{guix build} command allows
8493 you to repeat this option several times, in which case it builds for all the
8494 specified systems; other commands ignore extraneous @option{-s} options.
8497 The @code{--system} flag is for @emph{native} compilation and must not
8498 be confused with cross-compilation. See @code{--target} below for
8499 information on cross-compilation.
8502 An example use of this is on Linux-based systems, which can emulate
8503 different personalities. For instance, passing
8504 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8505 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8506 to build packages in a complete 32-bit environment.
8509 Building for an @code{armhf-linux} system is unconditionally enabled on
8510 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8511 allow for this functionality, notably the ThunderX.
8514 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8515 is enabled (@pxref{Virtualization Services,
8516 @code{qemu-binfmt-service-type}}), you can build for any system for
8517 which a QEMU @code{binfmt_misc} handler is installed.
8519 Builds for a system other than that of the machine you are using can
8520 also be offloaded to a remote machine of the right architecture.
8521 @xref{Daemon Offload Setup}, for more information on offloading.
8523 @item --target=@var{triplet}
8524 @cindex cross-compilation
8525 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8526 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8527 configuration triplets,, autoconf, Autoconf}).
8529 @anchor{build-check}
8531 @cindex determinism, checking
8532 @cindex reproducibility, checking
8533 Rebuild @var{package-or-derivation}, which are already available in the
8534 store, and raise an error if the build results are not bit-for-bit
8537 This mechanism allows you to check whether previously installed
8538 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8539 of a package is deterministic. @xref{Invoking guix challenge}, for more
8540 background information and tools.
8542 When used in conjunction with @option{--keep-failed}, the differing
8543 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8544 This makes it easy to look for differences between the two results.
8547 @cindex repairing store items
8548 @cindex corruption, recovering from
8549 Attempt to repair the specified store items, if they are corrupt, by
8550 re-downloading or rebuilding them.
8552 This operation is not atomic and thus restricted to @code{root}.
8556 Return the derivation paths, not the output paths, of the given
8559 @item --root=@var{file}
8560 @itemx -r @var{file}
8561 @cindex GC roots, adding
8562 @cindex garbage collector roots, adding
8563 Make @var{file} a symlink to the result, and register it as a garbage
8566 Consequently, the results of this @command{guix build} invocation are
8567 protected from garbage collection until @var{file} is removed. When
8568 that option is omitted, build results are eligible for garbage
8569 collection as soon as the build completes. @xref{Invoking guix gc}, for
8573 @cindex build logs, access
8574 Return the build log file names or URLs for the given
8575 @var{package-or-derivation}, or raise an error if build logs are
8578 This works regardless of how packages or derivations are specified. For
8579 instance, the following invocations are equivalent:
8582 guix build --log-file `guix build -d guile`
8583 guix build --log-file `guix build guile`
8584 guix build --log-file guile
8585 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8588 If a log is unavailable locally, and unless @code{--no-substitutes} is
8589 passed, the command looks for a corresponding log on one of the
8590 substitute servers (as specified with @code{--substitute-urls}.)
8592 So for instance, imagine you want to see the build log of GDB on MIPS,
8593 but you are actually on an @code{x86_64} machine:
8596 $ guix build --log-file gdb -s mips64el-linux
8597 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8600 You can freely access a huge library of build logs!
8603 @node Debugging Build Failures
8604 @subsection Debugging Build Failures
8606 @cindex build failures, debugging
8607 When defining a new package (@pxref{Defining Packages}), you will
8608 probably find yourself spending some time debugging and tweaking the
8609 build until it succeeds. To do that, you need to operate the build
8610 commands yourself in an environment as close as possible to the one the
8613 To that end, the first thing to do is to use the @option{--keep-failed}
8614 or @option{-K} option of @command{guix build}, which will keep the
8615 failed build tree in @file{/tmp} or whatever directory you specified as
8616 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8618 From there on, you can @command{cd} to the failed build tree and source
8619 the @file{environment-variables} file, which contains all the
8620 environment variable definitions that were in place when the build
8621 failed. So let's say you're debugging a build failure in package
8622 @code{foo}; a typical session would look like this:
8626 @dots{} @i{build fails}
8627 $ cd /tmp/guix-build-foo.drv-0
8628 $ source ./environment-variables
8632 Now, you can invoke commands as if you were the daemon (almost) and
8633 troubleshoot your build process.
8635 Sometimes it happens that, for example, a package's tests pass when you
8636 run them manually but they fail when the daemon runs them. This can
8637 happen because the daemon runs builds in containers where, unlike in our
8638 environment above, network access is missing, @file{/bin/sh} does not
8639 exist, etc. (@pxref{Build Environment Setup}).
8641 In such cases, you may need to run inspect the build process from within
8642 a container similar to the one the build daemon creates:
8647 $ cd /tmp/guix-build-foo.drv-0
8648 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8649 [env]# source ./environment-variables
8653 Here, @command{guix environment -C} creates a container and spawns a new
8654 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8655 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8656 the container, which would may find handy while debugging. The
8657 @option{--no-grafts} option makes sure we get the exact same
8658 environment, with ungrafted packages (@pxref{Security Updates}, for more
8661 To get closer to a container like that used by the build daemon, we can
8662 remove @file{/bin/sh}:
8668 (Don't worry, this is harmless: this is all happening in the throw-away
8669 container created by @command{guix environment}.)
8671 The @command{strace} command is probably not in the search path, but we
8675 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8678 In this way, not only you will have reproduced the environment variables
8679 the daemon uses, you will also be running the build process in a container
8680 similar to the one the daemon uses.
8683 @node Invoking guix edit
8684 @section Invoking @command{guix edit}
8686 @cindex @command{guix edit}
8687 @cindex package definition, editing
8688 So many packages, so many source files! The @command{guix edit} command
8689 facilitates the life of users and packagers by pointing their editor at
8690 the source file containing the definition of the specified packages.
8694 guix edit gcc@@4.9 vim
8698 launches the program specified in the @code{VISUAL} or in the
8699 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8702 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8703 have created your own packages on @code{GUIX_PACKAGE_PATH}
8704 (@pxref{Package Modules}), you will be able to edit the package
8705 recipes. In other cases, you will be able to examine the read-only recipes
8706 for packages currently in the store.
8709 @node Invoking guix download
8710 @section Invoking @command{guix download}
8712 @cindex @command{guix download}
8713 @cindex downloading package sources
8714 When writing a package definition, developers typically need to download
8715 a source tarball, compute its SHA256 hash, and write that
8716 hash in the package definition (@pxref{Defining Packages}). The
8717 @command{guix download} tool helps with this task: it downloads a file
8718 from the given URI, adds it to the store, and prints both its file name
8719 in the store and its SHA256 hash.
8721 The fact that the downloaded file is added to the store saves bandwidth:
8722 when the developer eventually tries to build the newly defined package
8723 with @command{guix build}, the source tarball will not have to be
8724 downloaded again because it is already in the store. It is also a
8725 convenient way to temporarily stash files, which may be deleted
8726 eventually (@pxref{Invoking guix gc}).
8728 The @command{guix download} command supports the same URIs as used in
8729 package definitions. In particular, it supports @code{mirror://} URIs.
8730 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8731 Guile bindings for GnuTLS are available in the user's environment; when
8732 they are not available, an error is raised. @xref{Guile Preparations,
8733 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8734 GnuTLS-Guile}, for more information.
8736 @command{guix download} verifies HTTPS server certificates by loading
8737 the certificates of X.509 authorities from the directory pointed to by
8738 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8739 Certificates}), unless @option{--no-check-certificate} is used.
8741 The following options are available:
8744 @item --format=@var{fmt}
8746 Write the hash in the format specified by @var{fmt}. For more
8747 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8749 @item --no-check-certificate
8750 Do not validate the X.509 certificates of HTTPS servers.
8752 When using this option, you have @emph{absolutely no guarantee} that you
8753 are communicating with the authentic server responsible for the given
8754 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8756 @item --output=@var{file}
8757 @itemx -o @var{file}
8758 Save the downloaded file to @var{file} instead of adding it to the
8762 @node Invoking guix hash
8763 @section Invoking @command{guix hash}
8765 @cindex @command{guix hash}
8766 The @command{guix hash} command computes the SHA256 hash of a file.
8767 It is primarily a convenience tool for anyone contributing to the
8768 distribution: it computes the cryptographic hash of a file, which can be
8769 used in the definition of a package (@pxref{Defining Packages}).
8771 The general syntax is:
8774 guix hash @var{option} @var{file}
8777 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8778 hash of data read from standard input. @command{guix hash} has the
8783 @item --format=@var{fmt}
8785 Write the hash in the format specified by @var{fmt}.
8787 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8788 (@code{hex} and @code{hexadecimal} can be used as well).
8790 If the @option{--format} option is not specified, @command{guix hash}
8791 will output the hash in @code{nix-base32}. This representation is used
8792 in the definitions of packages.
8796 Compute the hash on @var{file} recursively.
8798 In this case, the hash is computed on an archive containing @var{file},
8799 including its children if it is a directory. Some of the metadata of
8800 @var{file} is part of the archive; for instance, when @var{file} is a
8801 regular file, the hash is different depending on whether @var{file} is
8802 executable or not. Metadata such as time stamps has no impact on the
8803 hash (@pxref{Invoking guix archive}).
8804 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8809 When combined with @option{--recursive}, exclude version control system
8810 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8813 As an example, here is how you would compute the hash of a Git checkout,
8814 which is useful when using the @code{git-fetch} method (@pxref{origin
8818 $ git clone http://example.org/foo.git
8824 @node Invoking guix import
8825 @section Invoking @command{guix import}
8827 @cindex importing packages
8828 @cindex package import
8829 @cindex package conversion
8830 @cindex Invoking @command{guix import}
8831 The @command{guix import} command is useful for people who would like to
8832 add a package to the distribution with as little work as
8833 possible---a legitimate demand. The command knows of a few
8834 repositories from which it can ``import'' package metadata. The result
8835 is a package definition, or a template thereof, in the format we know
8836 (@pxref{Defining Packages}).
8838 The general syntax is:
8841 guix import @var{importer} @var{options}@dots{}
8844 @var{importer} specifies the source from which to import package
8845 metadata, and @var{options} specifies a package identifier and other
8846 options specific to @var{importer}.
8848 Some of the importers rely on the ability to run the @command{gpgv} command.
8849 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
8852 Currently, the available ``importers'' are:
8856 Import metadata for the given GNU package. This provides a template
8857 for the latest version of that GNU package, including the hash of its
8858 source tarball, and its canonical synopsis and description.
8860 Additional information such as the package dependencies and its
8861 license needs to be figured out manually.
8863 For example, the following command returns a package definition for
8867 guix import gnu hello
8870 Specific command-line options are:
8873 @item --key-download=@var{policy}
8874 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8875 keys when verifying the package signature. @xref{Invoking guix
8876 refresh, @code{--key-download}}.
8881 Import metadata from the @uref{https://pypi.python.org/, Python Package
8882 Index}. Information is taken from the JSON-formatted description
8883 available at @code{pypi.python.org} and usually includes all the relevant
8884 information, including package dependencies. For maximum efficiency, it
8885 is recommended to install the @command{unzip} utility, so that the
8886 importer can unzip Python wheels and gather data from them.
8888 The command below imports metadata for the @code{itsdangerous} Python
8892 guix import pypi itsdangerous
8898 Traverse the dependency graph of the given upstream package recursively
8899 and generate package expressions for all those packages that are not yet
8905 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8906 is taken from the JSON-formatted description available at
8907 @code{rubygems.org} and includes most relevant information, including
8908 runtime dependencies. There are some caveats, however. The metadata
8909 doesn't distinguish between synopses and descriptions, so the same string
8910 is used for both fields. Additionally, the details of non-Ruby
8911 dependencies required to build native extensions is unavailable and left
8912 as an exercise to the packager.
8914 The command below imports metadata for the @code{rails} Ruby package:
8917 guix import gem rails
8923 Traverse the dependency graph of the given upstream package recursively
8924 and generate package expressions for all those packages that are not yet
8930 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8931 Information is taken from the JSON-formatted metadata provided through
8932 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8933 relevant information, such as module dependencies. License information
8934 should be checked closely. If Perl is available in the store, then the
8935 @code{corelist} utility will be used to filter core modules out of the
8936 list of dependencies.
8938 The command command below imports metadata for the @code{Acme::Boolean}
8942 guix import cpan Acme::Boolean
8947 @cindex Bioconductor
8948 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8949 central repository for the @uref{https://r-project.org, GNU@tie{}R
8950 statistical and graphical environment}.
8952 Information is extracted from the @code{DESCRIPTION} file of the package.
8954 The command command below imports metadata for the @code{Cairo}
8958 guix import cran Cairo
8961 When @code{--recursive} is added, the importer will traverse the
8962 dependency graph of the given upstream package recursively and generate
8963 package expressions for all those packages that are not yet in Guix.
8965 When @code{--archive=bioconductor} is added, metadata is imported from
8966 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8967 packages for for the analysis and comprehension of high-throughput
8968 genomic data in bioinformatics.
8970 Information is extracted from the @code{DESCRIPTION} file contained in the
8973 The command below imports metadata for the @code{GenomicRanges}
8977 guix import cran --archive=bioconductor GenomicRanges
8980 Finally, you can also import R packages that have not yet been published on
8981 CRAN or Bioconductor as long as they are in a git repository. Use
8982 @code{--archive=git} followed by the URL of the git repository:
8985 guix import cran --archive=git https://github.com/immunogenomics/harmony
8991 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8992 comprehensive TeX archive network for TeX packages that are part of the
8993 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8995 Information about the package is obtained through the XML API provided
8996 by CTAN, while the source code is downloaded from the SVN repository of
8997 the Tex Live project. This is done because the CTAN does not keep
9000 The command command below imports metadata for the @code{fontspec}
9004 guix import texlive fontspec
9007 When @code{--archive=DIRECTORY} is added, the source code is downloaded
9008 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
9009 tree in the TeX Live SVN repository, but from the specified sibling
9010 directory under the same root.
9012 The command below imports metadata for the @code{ifxetex} package from
9013 CTAN while fetching the sources from the directory
9014 @file{texmf/source/generic}:
9017 guix import texlive --archive=generic ifxetex
9021 @cindex JSON, import
9022 Import package metadata from a local JSON file. Consider the following
9023 example package definition in JSON format:
9029 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9030 "build-system": "gnu",
9031 "home-page": "https://www.gnu.org/software/hello/",
9032 "synopsis": "Hello, GNU world: An example GNU package",
9033 "description": "GNU Hello prints a greeting.",
9034 "license": "GPL-3.0+",
9035 "native-inputs": ["gettext"]
9039 The field names are the same as for the @code{<package>} record
9040 (@xref{Defining Packages}). References to other packages are provided
9041 as JSON lists of quoted package specification strings such as
9042 @code{guile} or @code{guile@@2.0}.
9044 The importer also supports a more explicit source definition using the
9045 common fields for @code{<origin>} records:
9051 "method": "url-fetch",
9052 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9054 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9061 The command below reads metadata from the JSON file @code{hello.json}
9062 and outputs a package expression:
9065 guix import json hello.json
9069 Import metadata from a local copy of the source of the
9070 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9071 relies on the @command{nix-instantiate} command of
9072 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9073 typically written in a mixture of Nix-language and Bash code. This
9074 command only imports the high-level package structure that is written in
9075 the Nix language. It normally includes all the basic fields of a
9078 When importing a GNU package, the synopsis and descriptions are replaced
9079 by their canonical upstream variant.
9081 Usually, you will first need to do:
9084 export NIX_REMOTE=daemon
9088 so that @command{nix-instantiate} does not try to open the Nix database.
9090 As an example, the command below imports the package definition of
9091 LibreOffice (more precisely, it imports the definition of the package
9092 bound to the @code{libreoffice} top-level attribute):
9095 guix import nix ~/path/to/nixpkgs libreoffice
9100 Import metadata from the Haskell community's central package archive
9101 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9102 Cabal files and includes all the relevant information, including package
9105 Specific command-line options are:
9110 Read a Cabal file from standard input.
9111 @item --no-test-dependencies
9113 Do not include dependencies required only by the test suites.
9114 @item --cabal-environment=@var{alist}
9115 @itemx -e @var{alist}
9116 @var{alist} is a Scheme alist defining the environment in which the
9117 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9118 @code{arch}, @code{impl} and a string representing the name of a flag.
9119 The value associated with a flag has to be either the symbol
9120 @code{true} or @code{false}. The value associated with other keys
9121 has to conform to the Cabal file format definition. The default value
9122 associated with the keys @code{os}, @code{arch} and @code{impl} is
9123 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9126 Traverse the dependency graph of the given upstream package recursively
9127 and generate package expressions for all those packages that are not yet
9131 The command below imports metadata for the latest version of the
9132 @code{HTTP} Haskell package without including test dependencies and
9133 specifying the value of the flag @samp{network-uri} as @code{false}:
9136 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9139 A specific package version may optionally be specified by following the
9140 package name by an at-sign and a version number as in the following example:
9143 guix import hackage mtl@@2.1.3.1
9148 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9149 It takes a package name, looks up the package version included in a
9150 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9151 release and uses the @code{hackage} importer to retrieve its metadata.
9152 Note that it is up to you to select an LTS release compatible with the
9153 GHC compiler used by Guix.
9155 Specific command-line options are:
9158 @item --no-test-dependencies
9160 Do not include dependencies required only by the test suites.
9161 @item --lts-version=@var{version}
9162 @itemx -l @var{version}
9163 @var{version} is the desired LTS release version. If omitted the latest
9167 Traverse the dependency graph of the given upstream package recursively
9168 and generate package expressions for all those packages that are not yet
9172 The command below imports metadata for the @code{HTTP} Haskell package
9173 included in the LTS Stackage release version 7.18:
9176 guix import stackage --lts-version=7.18 HTTP
9181 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9182 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9184 Specific command-line options are:
9187 @item --archive=@var{repo}
9188 @itemx -a @var{repo}
9189 @var{repo} identifies the archive repository from which to retrieve the
9190 information. Currently the supported repositories and their identifiers
9194 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9195 identifier. This is the default.
9197 Packages from @code{elpa.gnu.org} are signed with one of the keys
9198 contained in the GnuPG keyring at
9199 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9200 @code{emacs} package (@pxref{Package Installation, ELPA package
9201 signatures,, emacs, The GNU Emacs Manual}).
9204 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9205 @code{melpa-stable} identifier.
9208 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9214 Traverse the dependency graph of the given upstream package recursively
9215 and generate package expressions for all those packages that are not yet
9221 Import metadata from the crates.io Rust package repository
9222 @uref{https://crates.io, crates.io}, as in this example:
9225 guix import crate blake2-rfc
9228 The crate importer also allows you to specify a version string:
9231 guix import crate constant-time-eq@@0.1.0
9234 Additional options include:
9239 Traverse the dependency graph of the given upstream package recursively
9240 and generate package expressions for all those packages that are not yet
9247 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9248 repository used by the OCaml community.
9251 The structure of the @command{guix import} code is modular. It would be
9252 useful to have more importers for other package formats, and your help
9253 is welcome here (@pxref{Contributing}).
9255 @node Invoking guix refresh
9256 @section Invoking @command{guix refresh}
9258 @cindex @command {guix refresh}
9259 The primary audience of the @command{guix refresh} command is developers
9260 of the GNU software distribution. By default, it reports any packages
9261 provided by the distribution that are outdated compared to the latest
9262 upstream version, like this:
9266 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9267 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9270 Alternately, one can specify packages to consider, in which case a
9271 warning is emitted for packages that lack an updater:
9274 $ guix refresh coreutils guile guile-ssh
9275 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9276 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9279 @command{guix refresh} browses the upstream repository of each package and determines
9280 the highest version number of the releases therein. The command
9281 knows how to update specific types of packages: GNU packages, ELPA
9282 packages, etc.---see the documentation for @option{--type} below. There
9283 are many packages, though, for which it lacks a method to determine
9284 whether a new upstream release is available. However, the mechanism is
9285 extensible, so feel free to get in touch with us to add a new method!
9290 Consider the packages specified, and all the packages upon which they depend.
9293 $ guix refresh --recursive coreutils
9294 gnu/packages/acl.scm:35:2: warning: no updater for acl
9295 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9296 gnu/packages/xml.scm:68:2: warning: no updater for expat
9297 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9303 Sometimes the upstream name differs from the package name used in Guix,
9304 and @command{guix refresh} needs a little help. Most updaters honor the
9305 @code{upstream-name} property in package definitions, which can be used
9309 (define-public network-manager
9311 (name "network-manager")
9313 (properties '((upstream-name . "NetworkManager")))))
9316 When passed @code{--update}, it modifies distribution source files to
9317 update the version numbers and source tarball hashes of those package
9318 recipes (@pxref{Defining Packages}). This is achieved by downloading
9319 each package's latest source tarball and its associated OpenPGP
9320 signature, authenticating the downloaded tarball against its signature
9321 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9322 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9325 key used to sign the tarball is missing from the user's keyring, an
9326 attempt is made to automatically retrieve it from a public key server;
9327 when this is successful, the key is added to the user's keyring; otherwise,
9328 @command{guix refresh} reports an error.
9330 The following options are supported:
9334 @item --expression=@var{expr}
9335 @itemx -e @var{expr}
9336 Consider the package @var{expr} evaluates to.
9338 This is useful to precisely refer to a package, as in this example:
9341 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9344 This command lists the dependents of the ``final'' libc (essentially all
9349 Update distribution source files (package recipes) in place. This is
9350 usually run from a checkout of the Guix source tree (@pxref{Running
9351 Guix Before It Is Installed}):
9354 $ ./pre-inst-env guix refresh -s non-core -u
9357 @xref{Defining Packages}, for more information on package definitions.
9359 @item --select=[@var{subset}]
9360 @itemx -s @var{subset}
9361 Select all the packages in @var{subset}, one of @code{core} or
9364 The @code{core} subset refers to all the packages at the core of the
9365 distribution---i.e., packages that are used to build ``everything
9366 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9367 changing one of these packages in the distribution entails a rebuild of
9368 all the others. Thus, such updates are an inconvenience to users in
9369 terms of build time or bandwidth used to achieve the upgrade.
9371 The @code{non-core} subset refers to the remaining packages. It is
9372 typically useful in cases where an update of the core packages would be
9375 @item --manifest=@var{file}
9376 @itemx -m @var{file}
9377 Select all the packages from the manifest in @var{file}. This is useful to
9378 check if any packages of the user manifest can be updated.
9380 @item --type=@var{updater}
9381 @itemx -t @var{updater}
9382 Select only packages handled by @var{updater} (may be a comma-separated
9383 list of updaters). Currently, @var{updater} may be one of:
9387 the updater for GNU packages;
9389 the updater for GNOME packages;
9391 the updater for KDE packages;
9393 the updater for X.org packages;
9395 the updater for packages hosted on kernel.org;
9397 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9399 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9401 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9403 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9405 the updater for @uref{https://pypi.python.org, PyPI} packages.
9407 the updater for @uref{https://rubygems.org, RubyGems} packages.
9409 the updater for @uref{https://github.com, GitHub} packages.
9411 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9413 the updater for @uref{https://www.stackage.org, Stackage} packages.
9415 the updater for @uref{https://crates.io, Crates} packages.
9417 the updater for @uref{https://launchpad.net, Launchpad} packages.
9420 For instance, the following command only checks for updates of Emacs
9421 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9424 $ guix refresh --type=elpa,cran
9425 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9426 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9431 In addition, @command{guix refresh} can be passed one or more package
9432 names, as in this example:
9435 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9439 The command above specifically updates the @code{emacs} and
9440 @code{idutils} packages. The @code{--select} option would have no
9441 effect in this case.
9443 When considering whether to upgrade a package, it is sometimes
9444 convenient to know which packages would be affected by the upgrade and
9445 should be checked for compatibility. For this the following option may
9446 be used when passing @command{guix refresh} one or more package names:
9450 @item --list-updaters
9452 List available updaters and exit (see @option{--type} above.)
9454 For each updater, display the fraction of packages it covers; at the
9455 end, display the fraction of packages covered by all these updaters.
9457 @item --list-dependent
9459 List top-level dependent packages that would need to be rebuilt as a
9460 result of upgrading one or more packages.
9462 @xref{Invoking guix graph, the @code{reverse-package} type of
9463 @command{guix graph}}, for information on how to visualize the list of
9464 dependents of a package.
9468 Be aware that the @code{--list-dependent} option only
9469 @emph{approximates} the rebuilds that would be required as a result of
9470 an upgrade. More rebuilds might be required under some circumstances.
9473 $ guix refresh --list-dependent flex
9474 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9475 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9478 The command above lists a set of packages that could be built to check
9479 for compatibility with an upgraded @code{flex} package.
9483 @item --list-transitive
9484 List all the packages which one or more packages depend upon.
9487 $ guix refresh --list-transitive flex
9488 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9489 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{}
9494 The command above lists a set of packages which, when changed, would cause
9495 @code{flex} to be rebuilt.
9497 The following options can be used to customize GnuPG operation:
9501 @item --gpg=@var{command}
9502 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9503 for in @code{$PATH}.
9505 @item --keyring=@var{file}
9506 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9507 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9508 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9509 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9510 information on a tool to manipulate keybox files).
9512 When this option is omitted, @command{guix refresh} uses
9513 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9514 signing keys. OpenPGP signatures are checked against keys from this keyring;
9515 missing keys are downloaded to this keyring as well (see
9516 @option{--key-download} below.)
9518 You can export keys from your default GPG keyring into a keybox file using
9519 commands like this one:
9522 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9525 Likewise, you can fetch keys to a specific keybox file like this:
9528 gpg --no-default-keyring --keyring mykeyring.kbx \
9529 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9532 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9533 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9535 @item --key-download=@var{policy}
9536 Handle missing OpenPGP keys according to @var{policy}, which may be one
9541 Always download missing OpenPGP keys from the key server, and add them
9542 to the user's GnuPG keyring.
9545 Never try to download missing OpenPGP keys. Instead just bail out.
9548 When a package signed with an unknown OpenPGP key is encountered, ask
9549 the user whether to download it or not. This is the default behavior.
9552 @item --key-server=@var{host}
9553 Use @var{host} as the OpenPGP key server when importing a public key.
9557 The @code{github} updater uses the
9558 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9559 releases. When used repeatedly e.g.@: when refreshing all packages,
9560 GitHub will eventually refuse to answer any further API requests. By
9561 default 60 API requests per hour are allowed, and a full refresh on all
9562 GitHub packages in Guix requires more than this. Authentication with
9563 GitHub through the use of an API token alleviates these limits. To use
9564 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9565 token procured from @uref{https://github.com/settings/tokens} or
9569 @node Invoking guix lint
9570 @section Invoking @command{guix lint}
9572 @cindex @command{guix lint}
9573 @cindex package, checking for errors
9574 The @command{guix lint} command is meant to help package developers avoid
9575 common errors and use a consistent style. It runs a number of checks on
9576 a given set of packages in order to find common mistakes in their
9577 definitions. Available @dfn{checkers} include (see
9578 @code{--list-checkers} for a complete list):
9583 Validate certain typographical and stylistic rules about package
9584 descriptions and synopses.
9586 @item inputs-should-be-native
9587 Identify inputs that should most likely be native inputs.
9593 @itemx source-file-name
9594 Probe @code{home-page} and @code{source} URLs and report those that are
9595 invalid. Suggest a @code{mirror://} URL when applicable. If the
9596 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9597 URL. Check that the source file name is meaningful, e.g.@: is not just a
9598 version number or ``git-checkout'', without a declared @code{file-name}
9599 (@pxref{origin Reference}).
9601 @item source-unstable-tarball
9602 Parse the @code{source} URL to determine if a tarball from GitHub is
9603 autogenerated or if it is a release tarball. Unfortunately GitHub's
9604 autogenerated tarballs are sometimes regenerated.
9607 @cindex Software Heritage, source code archive
9608 @cindex archival of source code, Software Heritage
9609 Checks whether the package's source code is archived at
9610 @uref{https://www.softwareheritage.org, Software Heritage}.
9612 When the source code that is not archived comes from a version-control system
9613 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9614 ``save'' request so that it eventually archives it. This ensures that the
9615 source will remain available in the long term, and that Guix can fall back to
9616 Software Heritage should the source code disappear from its original host.
9617 The status of recent ``save'' requests can be
9618 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9620 When source code is a tarball obtained with @code{url-fetch}, simply print a
9621 message when it is not archived. As of this writing, Software Heritage does
9622 not allow requests to save arbitrary tarballs; we are working on ways to
9623 ensure that non-VCS source code is also archived.
9626 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9627 request rate per IP address}. When the limit is reached, @command{guix lint}
9628 prints a message and the @code{archival} checker stops doing anything until
9629 that limit has been reset.
9632 @cindex security vulnerabilities
9633 @cindex CVE, Common Vulnerabilities and Exposures
9634 Report known vulnerabilities found in the Common Vulnerabilities and
9635 Exposures (CVE) databases of the current and past year
9636 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9639 To view information about a particular vulnerability, visit pages such as:
9643 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9645 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9649 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9650 @code{CVE-2015-7554}.
9652 Package developers can specify in package recipes the
9653 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9654 name and version of the package when they differ from the name or version
9655 that Guix uses, as in this example:
9661 ;; CPE calls this package "grub2".
9662 (properties '((cpe-name . "grub2")
9663 (cpe-version . "2.3"))))
9666 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9667 Some entries in the CVE database do not specify which version of a
9668 package they apply to, and would thus ``stick around'' forever. Package
9669 developers who found CVE alerts and verified they can be ignored can
9670 declare them as in this example:
9676 ;; These CVEs no longer apply and can be safely ignored.
9677 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9680 "CVE-2011-5244")))))
9684 Warn about obvious source code formatting issues: trailing white space,
9685 use of tabulations, etc.
9688 The general syntax is:
9691 guix lint @var{options} @var{package}@dots{}
9694 If no package is given on the command line, then all packages are checked.
9695 The @var{options} may be zero or more of the following:
9698 @item --list-checkers
9700 List and describe all the available checkers that will be run on packages
9705 Only enable the checkers specified in a comma-separated list using the
9706 names returned by @code{--list-checkers}.
9708 @item --load-path=@var{directory}
9709 @itemx -L @var{directory}
9710 Add @var{directory} to the front of the package module search path
9711 (@pxref{Package Modules}).
9713 This allows users to define their own packages and make them visible to
9714 the command-line tools.
9718 @node Invoking guix size
9719 @section Invoking @command{guix size}
9722 @cindex package size
9724 @cindex @command{guix size}
9725 The @command{guix size} command helps package developers profile the
9726 disk usage of packages. It is easy to overlook the impact of an
9727 additional dependency added to a package, or the impact of using a
9728 single output for a package that could easily be split (@pxref{Packages
9729 with Multiple Outputs}). Such are the typical issues that
9730 @command{guix size} can highlight.
9732 The command can be passed one or more package specifications
9733 such as @code{gcc@@4.8}
9734 or @code{guile:debug}, or a file name in the store. Consider this
9738 $ guix size coreutils
9739 store item total self
9740 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9741 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9742 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9743 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9744 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9745 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9746 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9747 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9752 The store items listed here constitute the @dfn{transitive closure} of
9753 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9754 would be returned by:
9757 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9760 Here the output shows three columns next to store items. The first column,
9761 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9762 the store item---that is, its own size plus the size of all its
9763 dependencies. The next column, labeled ``self'', shows the size of the
9764 item itself. The last column shows the ratio of the size of the item
9765 itself to the space occupied by all the items listed here.
9767 In this example, we see that the closure of Coreutils weighs in at
9768 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9769 libraries. (That libc and GCC's libraries represent a large fraction of
9770 the closure is not a problem @i{per se} because they are always available
9771 on the system anyway.)
9773 When the package(s) passed to @command{guix size} are available in the
9774 store@footnote{More precisely, @command{guix size} looks for the
9775 @emph{ungrafted} variant of the given package(s), as returned by
9776 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9777 for information on grafts.}, @command{guix size} queries the daemon to determine its
9778 dependencies, and measures its size in the store, similar to @command{du
9779 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9782 When the given packages are @emph{not} in the store, @command{guix size}
9783 reports information based on the available substitutes
9784 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9785 store items that are not even on disk, only available remotely.
9787 You can also specify several package names:
9790 $ guix size coreutils grep sed bash
9791 store item total self
9792 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9793 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9794 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9795 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9801 In this example we see that the combination of the four packages takes
9802 102.3@tie{}MiB in total, which is much less than the sum of each closure
9803 since they have a lot of dependencies in common.
9805 The available options are:
9809 @item --substitute-urls=@var{urls}
9810 Use substitute information from @var{urls}.
9811 @xref{client-substitute-urls, the same option for @code{guix build}}.
9813 @item --sort=@var{key}
9814 Sort lines according to @var{key}, one of the following options:
9818 the size of each item (the default);
9820 the total size of the item's closure.
9823 @item --map-file=@var{file}
9824 Write a graphical map of disk usage in PNG format to @var{file}.
9826 For the example above, the map looks like this:
9828 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9829 produced by @command{guix size}}
9831 This option requires that
9832 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9833 installed and visible in Guile's module search path. When that is not
9834 the case, @command{guix size} fails as it tries to load it.
9836 @item --system=@var{system}
9837 @itemx -s @var{system}
9838 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9842 @node Invoking guix graph
9843 @section Invoking @command{guix graph}
9846 @cindex @command{guix graph}
9847 @cindex package dependencies
9848 Packages and their dependencies form a @dfn{graph}, specifically a
9849 directed acyclic graph (DAG). It can quickly become difficult to have a
9850 mental model of the package DAG, so the @command{guix graph} command
9851 provides a visual representation of the DAG. By default,
9852 @command{guix graph} emits a DAG representation in the input format of
9853 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9854 directly to the @command{dot} command of Graphviz. It can also emit an
9855 HTML page with embedded JavaScript code to display a ``chord diagram''
9856 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9857 emit Cypher queries to construct a graph in a graph database supporting
9858 the @uref{https://www.opencypher.org/, openCypher} query language.
9859 The general syntax is:
9862 guix graph @var{options} @var{package}@dots{}
9865 For example, the following command generates a PDF file representing the
9866 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9870 guix graph coreutils | dot -Tpdf > dag.pdf
9873 The output looks like this:
9875 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9877 Nice little graph, no?
9879 But there is more than one graph! The one above is concise: it is the
9880 graph of package objects, omitting implicit inputs such as GCC, libc,
9881 grep, etc. It is often useful to have such a concise graph, but
9882 sometimes one may want to see more details. @command{guix graph} supports
9883 several types of graphs, allowing you to choose the level of detail:
9887 This is the default type used in the example above. It shows the DAG of
9888 package objects, excluding implicit dependencies. It is concise, but
9889 filters out many details.
9891 @item reverse-package
9892 This shows the @emph{reverse} DAG of packages. For example:
9895 guix graph --type=reverse-package ocaml
9898 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9899 you are also interested in cases where OCaml is an implicit dependency, see
9900 @code{reverse-bag} below.)
9902 Note that for core packages this can yield huge graphs. If all you want
9903 is to know the number of packages that depend on a given package, use
9904 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9905 @option{--list-dependent}}).
9908 This is the package DAG, @emph{including} implicit inputs.
9910 For instance, the following command:
9913 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9916 ...@: yields this bigger graph:
9918 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9920 At the bottom of the graph, we see all the implicit inputs of
9921 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9923 Now, note that the dependencies of these implicit inputs---that is, the
9924 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9925 here, for conciseness.
9928 Similar to @code{bag-emerged}, but this time including all the bootstrap
9931 @item bag-with-origins
9932 Similar to @code{bag}, but also showing origins and their dependencies.
9935 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9936 it also takes implicit dependencies into account. For example:
9939 guix graph -t reverse-bag dune
9943 ...@: yields the graph of all packages that depend on Dune, directly or
9944 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9945 @i{via} @code{dune-build-system}, this shows a large number of packages,
9946 whereas @code{reverse-package} would show very few if any.
9949 This is the most detailed representation: It shows the DAG of
9950 derivations (@pxref{Derivations}) and plain store items. Compared to
9951 the above representation, many additional nodes are visible, including
9952 build scripts, patches, Guile modules, etc.
9954 For this type of graph, it is also possible to pass a @file{.drv} file
9955 name instead of a package name, as in:
9958 guix graph -t derivation `guix system build -d my-config.scm`
9962 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9963 For example, the following command shows the graph for the package
9964 module that defines the @code{guile} package:
9967 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9971 All the types above correspond to @emph{build-time dependencies}. The
9972 following graph type represents the @emph{run-time dependencies}:
9976 This is the graph of @dfn{references} of a package output, as returned
9977 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9979 If the given package output is not available in the store, @command{guix
9980 graph} attempts to obtain dependency information from substitutes.
9982 Here you can also pass a store file name instead of a package name. For
9983 example, the command below produces the reference graph of your profile
9984 (which can be big!):
9987 guix graph -t references `readlink -f ~/.guix-profile`
9991 This is the graph of the @dfn{referrers} of a store item, as returned by
9992 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9994 This relies exclusively on local information from your store. For
9995 instance, let us suppose that the current Inkscape is available in 10
9996 profiles on your machine; @command{guix graph -t referrers inkscape}
9997 will show a graph rooted at Inkscape and with those 10 profiles linked
10000 It can help determine what is preventing a store item from being garbage
10005 The available options are the following:
10008 @item --type=@var{type}
10009 @itemx -t @var{type}
10010 Produce a graph output of @var{type}, where @var{type} must be one of
10011 the values listed above.
10014 List the supported graph types.
10016 @item --backend=@var{backend}
10017 @itemx -b @var{backend}
10018 Produce a graph using the selected @var{backend}.
10020 @item --list-backends
10021 List the supported graph backends.
10023 Currently, the available backends are Graphviz and d3.js.
10025 @item --expression=@var{expr}
10026 @itemx -e @var{expr}
10027 Consider the package @var{expr} evaluates to.
10029 This is useful to precisely refer to a package, as in this example:
10032 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10035 @item --system=@var{system}
10036 @itemx -s @var{system}
10037 Display the graph for @var{system}---e.g., @code{i686-linux}.
10039 The package dependency graph is largely architecture-independent, but there
10040 are some architecture-dependent bits that this option allows you to visualize.
10043 On top of that, @command{guix graph} supports all the usual package
10044 transformation options (@pxref{Package Transformation Options}). This
10045 makes it easy to view the effect of a graph-rewriting transformation
10046 such as @option{--with-input}. For example, the command below outputs
10047 the graph of @code{git} once @code{openssl} has been replaced by
10048 @code{libressl} everywhere in the graph:
10051 guix graph git --with-input=openssl=libressl
10054 So many possibilities, so much fun!
10056 @node Invoking guix publish
10057 @section Invoking @command{guix publish}
10059 @cindex @command{guix publish}
10060 The purpose of @command{guix publish} is to enable users to easily share
10061 their store with others, who can then use it as a substitute server
10062 (@pxref{Substitutes}).
10064 When @command{guix publish} runs, it spawns an HTTP server which allows
10065 anyone with network access to obtain substitutes from it. This means
10066 that any machine running Guix can also act as if it were a build farm,
10067 since the HTTP interface is compatible with Cuirass, the software behind
10068 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10070 For security, each substitute is signed, allowing recipients to check
10071 their authenticity and integrity (@pxref{Substitutes}). Because
10072 @command{guix publish} uses the signing key of the system, which is only
10073 readable by the system administrator, it must be started as root; the
10074 @code{--user} option makes it drop root privileges early on.
10076 The signing key pair must be generated before @command{guix publish} is
10077 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10080 The general syntax is:
10083 guix publish @var{options}@dots{}
10086 Running @command{guix publish} without any additional arguments will
10087 spawn an HTTP server on port 8080:
10093 Once a publishing server has been authorized (@pxref{Invoking guix
10094 archive}), the daemon may download substitutes from it:
10097 guix-daemon --substitute-urls=http://example.org:8080
10100 By default, @command{guix publish} compresses archives on the fly as it
10101 serves them. This ``on-the-fly'' mode is convenient in that it requires
10102 no setup and is immediately available. However, when serving lots of
10103 clients, we recommend using the @option{--cache} option, which enables
10104 caching of the archives before they are sent to clients---see below for
10105 details. The @command{guix weather} command provides a handy way to
10106 check what a server provides (@pxref{Invoking guix weather}).
10108 As a bonus, @command{guix publish} also serves as a content-addressed
10109 mirror for source files referenced in @code{origin} records
10110 (@pxref{origin Reference}). For instance, assuming @command{guix
10111 publish} is running on @code{example.org}, the following URL returns the
10112 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10113 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10116 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10119 Obviously, these URLs only work for files that are in the store; in
10120 other cases, they return 404 (``Not Found'').
10122 @cindex build logs, publication
10123 Build logs are available from @code{/log} URLs like:
10126 http://example.org/log/gwspk@dots{}-guile-2.2.3
10130 When @command{guix-daemon} is configured to save compressed build logs,
10131 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10132 URLs return the compressed log as-is, with an appropriate
10133 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10134 running @command{guix-daemon} with @code{--log-compression=gzip} since
10135 Web browsers can automatically decompress it, which is not the case with
10138 The following options are available:
10141 @item --port=@var{port}
10142 @itemx -p @var{port}
10143 Listen for HTTP requests on @var{port}.
10145 @item --listen=@var{host}
10146 Listen on the network interface for @var{host}. The default is to
10147 accept connections from any interface.
10149 @item --user=@var{user}
10150 @itemx -u @var{user}
10151 Change privileges to @var{user} as soon as possible---i.e., once the
10152 server socket is open and the signing key has been read.
10154 @item --compression[=@var{method}[:@var{level}]]
10155 @itemx -C [@var{method}[:@var{level}]]
10156 Compress data using the given @var{method} and @var{level}. @var{method} is
10157 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10160 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10161 to different compression levels: 1 is the fastest, and 9 is the best
10162 (CPU-intensive). The default is 3.
10164 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10165 increase in CPU usage; see
10166 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10169 Unless @option{--cache} is used, compression occurs on the fly and
10170 the compressed streams are not
10171 cached. Thus, to reduce load on the machine that runs @command{guix
10172 publish}, it may be a good idea to choose a low compression level, to
10173 run @command{guix publish} behind a caching proxy, or to use
10174 @option{--cache}. Using @option{--cache} has the advantage that it
10175 allows @command{guix publish} to add @code{Content-Length} HTTP header
10178 This option can be repeated, in which case every substitute gets compressed
10179 using all the selected methods, and all of them are advertised. This is
10180 useful when users may not support all the compression methods: they can select
10181 the one they support.
10183 @item --cache=@var{directory}
10184 @itemx -c @var{directory}
10185 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10186 and only serve archives that are in cache.
10188 When this option is omitted, archives and meta-data are created
10189 on-the-fly. This can reduce the available bandwidth, especially when
10190 compression is enabled, since this may become CPU-bound. Another
10191 drawback of the default mode is that the length of archives is not known
10192 in advance, so @command{guix publish} does not add a
10193 @code{Content-Length} HTTP header to its responses, which in turn
10194 prevents clients from knowing the amount of data being downloaded.
10196 Conversely, when @option{--cache} is used, the first request for a store
10197 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10198 background process to @dfn{bake} the archive---computing its
10199 @code{.narinfo} and compressing the archive, if needed. Once the
10200 archive is cached in @var{directory}, subsequent requests succeed and
10201 are served directly from the cache, which guarantees that clients get
10202 the best possible bandwidth.
10204 The ``baking'' process is performed by worker threads. By default, one
10205 thread per CPU core is created, but this can be customized. See
10206 @option{--workers} below.
10208 When @option{--ttl} is used, cached entries are automatically deleted
10209 when they have expired.
10211 @item --workers=@var{N}
10212 When @option{--cache} is used, request the allocation of @var{N} worker
10213 threads to ``bake'' archives.
10215 @item --ttl=@var{ttl}
10216 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10217 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10218 days, @code{1m} means 1 month, and so on.
10220 This allows the user's Guix to keep substitute information in cache for
10221 @var{ttl}. However, note that @code{guix publish} does not itself
10222 guarantee that the store items it provides will indeed remain available
10223 for as long as @var{ttl}.
10225 Additionally, when @option{--cache} is used, cached entries that have
10226 not been accessed for @var{ttl} and that no longer have a corresponding
10227 item in the store, may be deleted.
10229 @item --nar-path=@var{path}
10230 Use @var{path} as the prefix for the URLs of ``nar'' files
10231 (@pxref{Invoking guix archive, normalized archives}).
10233 By default, nars are served at a URL such as
10234 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10235 change the @code{/nar} part to @var{path}.
10237 @item --public-key=@var{file}
10238 @itemx --private-key=@var{file}
10239 Use the specific @var{file}s as the public/private key pair used to sign
10240 the store items being published.
10242 The files must correspond to the same key pair (the private key is used
10243 for signing and the public key is merely advertised in the signature
10244 metadata). They must contain keys in the canonical s-expression format
10245 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10246 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10247 @file{/etc/guix/signing-key.sec} are used.
10249 @item --repl[=@var{port}]
10250 @itemx -r [@var{port}]
10251 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10252 Reference Manual}) on @var{port} (37146 by default). This is used
10253 primarily for debugging a running @command{guix publish} server.
10256 Enabling @command{guix publish} on Guix System is a one-liner: just
10257 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10258 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10259 @code{guix-publish-service-type}}).
10261 If you are instead running Guix on a ``foreign distro'', follow these
10266 If your host distro uses the systemd init system:
10269 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10270 /etc/systemd/system/
10271 # systemctl start guix-publish && systemctl enable guix-publish
10275 If your host distro uses the Upstart init system:
10278 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10279 # start guix-publish
10283 Otherwise, proceed similarly with your distro's init system.
10286 @node Invoking guix challenge
10287 @section Invoking @command{guix challenge}
10289 @cindex reproducible builds
10290 @cindex verifiable builds
10291 @cindex @command{guix challenge}
10293 Do the binaries provided by this server really correspond to the source
10294 code it claims to build? Is a package build process deterministic?
10295 These are the questions the @command{guix challenge} command attempts to
10298 The former is obviously an important question: Before using a substitute
10299 server (@pxref{Substitutes}), one had better @emph{verify} that it
10300 provides the right binaries, and thus @emph{challenge} it. The latter
10301 is what enables the former: If package builds are deterministic, then
10302 independent builds of the package should yield the exact same result,
10303 bit for bit; if a server provides a binary different from the one
10304 obtained locally, it may be either corrupt or malicious.
10306 We know that the hash that shows up in @file{/gnu/store} file names is
10307 the hash of all the inputs of the process that built the file or
10308 directory---compilers, libraries, build scripts,
10309 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10310 one store file name should map to exactly one build output.
10311 @command{guix challenge} checks whether there is, indeed, a single
10312 mapping by comparing the build outputs of several independent builds of
10313 any given store item.
10315 The command output looks like this:
10318 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10319 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10320 updating list of substitutes from 'https://guix.example.org'... 100.0%
10321 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10322 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10323 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10324 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10326 /lib/libcrypto.so.1.1
10329 /gnu/store/@dots{}-git-2.5.0 contents differ:
10330 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10331 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10332 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10334 /libexec/git-core/git-fsck
10336 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10337 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10338 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10339 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10341 /share/man/man1/pius.1.gz
10345 6,406 store items were analyzed:
10346 - 4,749 (74.1%) were identical
10347 - 525 (8.2%) differed
10348 - 1,132 (17.7%) were inconclusive
10352 In this example, @command{guix challenge} first scans the store to
10353 determine the set of locally-built derivations---as opposed to store
10354 items that were downloaded from a substitute server---and then queries
10355 all the substitute servers. It then reports those store items for which
10356 the servers obtained a result different from the local build.
10358 @cindex non-determinism, in package builds
10359 As an example, @code{guix.example.org} always gets a different answer.
10360 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10361 case of Git. This might indicate that the build process of Git is
10362 non-deterministic, meaning that its output varies as a function of
10363 various things that Guix does not fully control, in spite of building
10364 packages in isolated environments (@pxref{Features}). Most common
10365 sources of non-determinism include the addition of timestamps in build
10366 results, the inclusion of random numbers, and directory listings sorted
10367 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10370 To find out what is wrong with this Git binary, the easiest approach is
10374 guix challenge git \
10375 --diff=diffoscope \
10376 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10379 This automatically invokes @command{diffoscope}, which displays detailed
10380 information about files that differ.
10382 Alternately, we can do something along these lines (@pxref{Invoking guix
10386 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
10387 | guix archive -x /tmp/git
10388 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10391 This command shows the difference between the files resulting from the
10392 local build, and the files resulting from the build on
10393 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10394 diffutils, Comparing and Merging Files}). The @command{diff} command
10395 works great for text files. When binary files differ, a better option
10396 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10397 visualize differences for all kinds of files.
10399 Once you have done that work, you can tell whether the differences are due
10400 to a non-deterministic build process or to a malicious server. We try
10401 hard to remove sources of non-determinism in packages to make it easier
10402 to verify substitutes, but of course, this is a process that
10403 involves not just Guix, but a large part of the free software community.
10404 In the meantime, @command{guix challenge} is one tool to help address
10407 If you are writing packages for Guix, you are encouraged to check
10408 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10409 same build result as you did with:
10412 $ guix challenge @var{package}
10416 where @var{package} is a package specification such as
10417 @code{guile@@2.0} or @code{glibc:debug}.
10419 The general syntax is:
10422 guix challenge @var{options} [@var{packages}@dots{}]
10425 When a difference is found between the hash of a locally-built item and
10426 that of a server-provided substitute, or among substitutes provided by
10427 different servers, the command displays it as in the example above and
10428 its exit code is 2 (other non-zero exit codes denote other kinds of
10431 The one option that matters is:
10435 @item --substitute-urls=@var{urls}
10436 Consider @var{urls} the whitespace-separated list of substitute source
10437 URLs to compare to.
10439 @item --diff=@var{mode}
10440 Upon mismatches, show differences according to @var{mode}, one of:
10443 @item @code{simple} (the default)
10444 Show the list of files that differ.
10446 @item @code{diffoscope}
10447 @itemx @var{command}
10448 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
10449 two directories whose contents do not match.
10451 When @var{command} is an absolute file name, run @var{command} instead
10455 Do not show further details about the differences.
10458 Thus, unless @code{--diff=none} is passed, @command{guix challenge}
10459 downloads the store items from the given substitute servers so that it
10464 Show details about matches (identical contents) in addition to
10465 information about mismatches.
10469 @node Invoking guix copy
10470 @section Invoking @command{guix copy}
10472 @cindex copy, of store items, over SSH
10473 @cindex SSH, copy of store items
10474 @cindex sharing store items across machines
10475 @cindex transferring store items across machines
10476 The @command{guix copy} command copies items from the store of one
10477 machine to that of another machine over a secure shell (SSH)
10478 connection@footnote{This command is available only when Guile-SSH was
10479 found. @xref{Requirements}, for details.}. For example, the following
10480 command copies the @code{coreutils} package, the user's profile, and all
10481 their dependencies over to @var{host}, logged in as @var{user}:
10484 guix copy --to=@var{user}@@@var{host} \
10485 coreutils `readlink -f ~/.guix-profile`
10488 If some of the items to be copied are already present on @var{host},
10489 they are not actually sent.
10491 The command below retrieves @code{libreoffice} and @code{gimp} from
10492 @var{host}, assuming they are available there:
10495 guix copy --from=@var{host} libreoffice gimp
10498 The SSH connection is established using the Guile-SSH client, which is
10499 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10500 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10502 The key used to sign items that are sent must be accepted by the remote
10503 machine. Likewise, the key used by the remote machine to sign items you
10504 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10505 own daemon. @xref{Invoking guix archive}, for more information about
10506 store item authentication.
10508 The general syntax is:
10511 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10514 You must always specify one of the following options:
10517 @item --to=@var{spec}
10518 @itemx --from=@var{spec}
10519 Specify the host to send to or receive from. @var{spec} must be an SSH
10520 spec such as @code{example.org}, @code{charlie@@example.org}, or
10521 @code{charlie@@example.org:2222}.
10524 The @var{items} can be either package names, such as @code{gimp}, or
10525 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10527 When specifying the name of a package to send, it is first built if
10528 needed, unless @option{--dry-run} was specified. Common build options
10529 are supported (@pxref{Common Build Options}).
10532 @node Invoking guix container
10533 @section Invoking @command{guix container}
10535 @cindex @command{guix container}
10537 As of version @value{VERSION}, this tool is experimental. The interface
10538 is subject to radical change in the future.
10541 The purpose of @command{guix container} is to manipulate processes
10542 running within an isolated environment, commonly known as a
10543 ``container'', typically created by the @command{guix environment}
10544 (@pxref{Invoking guix environment}) and @command{guix system container}
10545 (@pxref{Invoking guix system}) commands.
10547 The general syntax is:
10550 guix container @var{action} @var{options}@dots{}
10553 @var{action} specifies the operation to perform with a container, and
10554 @var{options} specifies the context-specific arguments for the action.
10556 The following actions are available:
10560 Execute a command within the context of a running container.
10565 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10568 @var{pid} specifies the process ID of the running container.
10569 @var{program} specifies an executable file name within the root file
10570 system of the container. @var{arguments} are the additional options that
10571 will be passed to @var{program}.
10573 The following command launches an interactive login shell inside a
10574 Guix system container, started by @command{guix system container}, and whose
10575 process ID is 9001:
10578 guix container exec 9001 /run/current-system/profile/bin/bash --login
10581 Note that the @var{pid} cannot be the parent process of a container. It
10582 must be PID 1 of the container or one of its child processes.
10586 @node Invoking guix weather
10587 @section Invoking @command{guix weather}
10589 Occasionally you're grumpy because substitutes are lacking and you end
10590 up building packages by yourself (@pxref{Substitutes}). The
10591 @command{guix weather} command reports on substitute availability on the
10592 specified servers so you can have an idea of whether you'll be grumpy
10593 today. It can sometimes be useful info as a user, but it is primarily
10594 useful to people running @command{guix publish} (@pxref{Invoking guix
10597 @cindex statistics, for substitutes
10598 @cindex availability of substitutes
10599 @cindex substitute availability
10600 @cindex weather, substitute availability
10601 Here's a sample run:
10604 $ guix weather --substitute-urls=https://guix.example.org
10605 computing 5,872 package derivations for x86_64-linux...
10606 looking for 6,128 store items on https://guix.example.org..
10607 updating list of substitutes from 'https://guix.example.org'... 100.0%
10608 https://guix.example.org
10609 43.4% substitutes available (2,658 out of 6,128)
10610 7,032.5 MiB of nars (compressed)
10611 19,824.2 MiB on disk (uncompressed)
10612 0.030 seconds per request (182.9 seconds in total)
10613 33.5 requests per second
10615 9.8% (342 out of 3,470) of the missing items are queued
10617 x86_64-linux: 518 (59.7%)
10618 i686-linux: 221 (25.5%)
10619 aarch64-linux: 128 (14.8%)
10620 build rate: 23.41 builds per hour
10621 x86_64-linux: 11.16 builds per hour
10622 i686-linux: 6.03 builds per hour
10623 aarch64-linux: 6.41 builds per hour
10626 @cindex continuous integration, statistics
10627 As you can see, it reports the fraction of all the packages for which
10628 substitutes are available on the server---regardless of whether
10629 substitutes are enabled, and regardless of whether this server's signing
10630 key is authorized. It also reports the size of the compressed archives
10631 (``nars'') provided by the server, the size the corresponding store
10632 items occupy in the store (assuming deduplication is turned off), and
10633 the server's throughput. The second part gives continuous integration
10634 (CI) statistics, if the server supports it. In addition, using the
10635 @option{--coverage} option, @command{guix weather} can list ``important''
10636 package substitutes missing on the server (see below).
10638 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10639 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10640 challenge}, it ignores signatures on those substitutes, which is
10641 innocuous since the command only gathers statistics and cannot install
10644 The general syntax is:
10647 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10650 When @var{packages} is omitted, @command{guix weather} checks the availability
10651 of substitutes for @emph{all} the packages, or for those specified with
10652 @option{--manifest}; otherwise it only considers the specified packages. It
10653 is also possible to query specific system types with @option{--system}. The
10654 available options are listed below.
10657 @item --substitute-urls=@var{urls}
10658 @var{urls} is the space-separated list of substitute server URLs to
10659 query. When this option is omitted, the default set of substitute
10660 servers is queried.
10662 @item --system=@var{system}
10663 @itemx -s @var{system}
10664 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10665 option can be repeated, in which case @command{guix weather} will query
10666 substitutes for several system types.
10668 @item --manifest=@var{file}
10669 Instead of querying substitutes for all the packages, only ask for those
10670 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10671 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10674 @item --coverage[=@var{count}]
10675 @itemx -c [@var{count}]
10676 Report on substitute coverage for packages: list packages with at least
10677 @var{count} dependents (zero by default) for which substitutes are
10678 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10679 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10680 @var{b} usually lacks substitutes as well. The result looks like this:
10683 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10684 computing 8,983 package derivations for x86_64-linux...
10685 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10686 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10687 @value{SUBSTITUTE-URL}
10688 64.7% substitutes available (6,047 out of 9,343)
10690 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10691 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10692 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10693 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10697 What this example shows is that @code{kcoreaddons} and presumably the 58
10698 packages that depend on it have no substitutes at @code{ci.guix.info};
10699 likewise for @code{qgpgme} and the 46 packages that depend on it.
10701 If you are a Guix developer, or if you are taking care of this build farm,
10702 you'll probably want to have a closer look at these packages: they may simply
10706 @node Invoking guix processes
10707 @section Invoking @command{guix processes}
10709 The @command{guix processes} command can be useful to developers and system
10710 administrators, especially on multi-user machines and on build farms: it lists
10711 the current sessions (connections to the daemon), as well as information about
10712 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10713 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10714 listed.}. Here's an example of the information it returns:
10717 $ sudo guix processes
10720 ClientCommand: guix environment --ad-hoc python
10724 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10728 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10729 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10730 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10731 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10732 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10733 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10734 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10737 In this example we see that @command{guix-daemon} has three clients:
10738 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10739 integration tool; their process identifier (PID) is given by the
10740 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10741 @command{guix-daemon} sub-process of this particular session.
10743 The @code{LockHeld} fields show which store items are currently locked by this
10744 session, which corresponds to store items being built or substituted (the
10745 @code{LockHeld} field is not displayed when @command{guix processes} is not
10746 running as root.) Last, by looking at the @code{ChildProcess} field, we
10747 understand that these three builds are being offloaded (@pxref{Daemon Offload
10750 The output is in Recutils format so we can use the handy @command{recsel}
10751 command to select sessions of interest (@pxref{Selection Expressions,,,
10752 recutils, GNU recutils manual}). As an example, the command shows the command
10753 line and PID of the client that triggered the build of a Perl package:
10756 $ sudo guix processes | \
10757 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10759 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10762 @node System Configuration
10763 @chapter System Configuration
10765 @cindex system configuration
10766 Guix System supports a consistent whole-system configuration
10767 mechanism. By that we mean that all aspects of the global system
10768 configuration---such as the available system services, timezone and
10769 locale settings, user accounts---are declared in a single place. Such
10770 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10772 One of the advantages of putting all the system configuration under the
10773 control of Guix is that it supports transactional system upgrades, and
10774 makes it possible to roll back to a previous system instantiation,
10775 should something go wrong with the new one (@pxref{Features}). Another
10776 advantage is that it makes it easy to replicate the exact same configuration
10777 across different machines, or at different points in time, without
10778 having to resort to additional administration tools layered on top of
10779 the own tools of the system.
10780 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10782 This section describes this mechanism. First we focus on the system
10783 administrator's viewpoint---explaining how the system is configured and
10784 instantiated. Then we show how this mechanism can be extended, for
10785 instance to support new system services.
10788 * Using the Configuration System:: Customizing your GNU system.
10789 * operating-system Reference:: Detail of operating-system declarations.
10790 * File Systems:: Configuring file system mounts.
10791 * Mapped Devices:: Block device extra processing.
10792 * User Accounts:: Specifying user accounts.
10793 * Keyboard Layout:: How the system interprets key strokes.
10794 * Locales:: Language and cultural convention settings.
10795 * Services:: Specifying system services.
10796 * Setuid Programs:: Programs running with root privileges.
10797 * X.509 Certificates:: Authenticating HTTPS servers.
10798 * Name Service Switch:: Configuring libc's name service switch.
10799 * Initial RAM Disk:: Linux-Libre bootstrapping.
10800 * Bootloader Configuration:: Configuring the boot loader.
10801 * Invoking guix system:: Instantiating a system configuration.
10802 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10803 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10804 * Defining Services:: Adding new service definitions.
10807 @node Using the Configuration System
10808 @section Using the Configuration System
10810 The operating system is configured by providing an
10811 @code{operating-system} declaration in a file that can then be passed to
10812 the @command{guix system} command (@pxref{Invoking guix system}). A
10813 simple setup, with the default system services, the default Linux-Libre
10814 kernel, initial RAM disk, and boot loader looks like this:
10816 @findex operating-system
10818 @include os-config-bare-bones.texi
10821 This example should be self-describing. Some of the fields defined
10822 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10823 Others, such as @code{packages} and @code{services}, can be omitted, in
10824 which case they get a default value.
10826 Below we discuss the effect of some of the most important fields
10827 (@pxref{operating-system Reference}, for details about all the available
10828 fields), and how to @dfn{instantiate} the operating system using
10829 @command{guix system}.
10831 @unnumberedsubsec Bootloader
10833 @cindex legacy boot, on Intel machines
10834 @cindex BIOS boot, on Intel machines
10837 The @code{bootloader} field describes the method that will be used to boot
10838 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10839 mode, as in the example above. However, more recent machines rely instead on
10840 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10841 the @code{bootloader} field should contain something along these lines:
10844 (bootloader-configuration
10845 (bootloader grub-efi-bootloader)
10846 (target "/boot/efi"))
10849 @xref{Bootloader Configuration}, for more information on the available
10850 configuration options.
10852 @unnumberedsubsec Globally-Visible Packages
10854 @vindex %base-packages
10855 The @code{packages} field lists packages that will be globally visible
10856 on the system, for all user accounts---i.e., in every user's @code{PATH}
10857 environment variable---in addition to the per-user profiles
10858 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10859 provides all the tools one would expect for basic user and administrator
10860 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10861 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10862 etc. The example above adds GNU@tie{}Screen to those,
10863 taken from the @code{(gnu packages screen)}
10864 module (@pxref{Package Modules}). The
10865 @code{(list package output)} syntax can be used to add a specific output
10869 (use-modules (gnu packages))
10870 (use-modules (gnu packages dns))
10874 (packages (cons (list bind "utils")
10878 @findex specification->package
10879 Referring to packages by variable name, like @code{bind} above, has
10880 the advantage of being unambiguous; it also allows typos and such to be
10881 diagnosed right away as ``unbound variables''. The downside is that one
10882 needs to know which module defines which package, and to augment the
10883 @code{use-package-modules} line accordingly. To avoid that, one can use
10884 the @code{specification->package} procedure of the @code{(gnu packages)}
10885 module, which returns the best package for a given name or name and
10889 (use-modules (gnu packages))
10893 (packages (append (map specification->package
10894 '("tcpdump" "htop" "gnupg@@2.0"))
10898 @unnumberedsubsec System Services
10901 @vindex %base-services
10902 The @code{services} field lists @dfn{system services} to be made
10903 available when the system starts (@pxref{Services}).
10904 The @code{operating-system} declaration above specifies that, in
10905 addition to the basic services, we want the OpenSSH secure shell
10906 daemon listening on port 2222 (@pxref{Networking Services,
10907 @code{openssh-service-type}}). Under the hood,
10908 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10909 right command-line options, possibly with supporting configuration files
10910 generated as needed (@pxref{Defining Services}).
10912 @cindex customization, of services
10913 @findex modify-services
10914 Occasionally, instead of using the base services as is, you will want to
10915 customize them. To do this, use @code{modify-services} (@pxref{Service
10916 Reference, @code{modify-services}}) to modify the list.
10918 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10919 (the console log-in) in the @code{%base-services} list (@pxref{Base
10920 Services, @code{%base-services}}). To do that, you can write the
10921 following in your operating system declaration:
10924 (define %my-services
10925 ;; My very own list of services.
10926 (modify-services %base-services
10927 (guix-service-type config =>
10928 (guix-configuration
10930 (use-substitutes? #f)
10931 (extra-options '("--gc-keep-derivations"))))
10932 (mingetty-service-type config =>
10933 (mingetty-configuration
10934 (inherit config)))))
10938 (services %my-services))
10941 This changes the configuration---i.e., the service parameters---of the
10942 @code{guix-service-type} instance, and that of all the
10943 @code{mingetty-service-type} instances in the @code{%base-services} list.
10944 Observe how this is accomplished: first, we arrange for the original
10945 configuration to be bound to the identifier @code{config} in the
10946 @var{body}, and then we write the @var{body} so that it evaluates to the
10947 desired configuration. In particular, notice how we use @code{inherit}
10948 to create a new configuration which has the same values as the old
10949 configuration, but with a few modifications.
10951 @cindex encrypted disk
10952 The configuration for a typical ``desktop'' usage, with an encrypted
10953 root partition, the X11 display
10954 server, GNOME and Xfce (users can choose which of these desktop
10955 environments to use at the log-in screen by pressing @kbd{F1}), network
10956 management, power management, and more, would look like this:
10959 @include os-config-desktop.texi
10962 A graphical system with a choice of lightweight window managers
10963 instead of full-blown desktop environments would look like this:
10966 @include os-config-lightweight-desktop.texi
10969 This example refers to the @file{/boot/efi} file system by its UUID,
10970 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10971 as returned by the @command{blkid} command.
10973 @xref{Desktop Services}, for the exact list of services provided by
10974 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10975 information about the @code{nss-certs} package that is used here.
10977 Again, @code{%desktop-services} is just a list of service objects. If
10978 you want to remove services from there, you can do so using the
10979 procedures for list filtering (@pxref{SRFI-1 Filtering and
10980 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10981 following expression returns a list that contains all the services in
10982 @code{%desktop-services} minus the Avahi service:
10985 (remove (lambda (service)
10986 (eq? (service-kind service) avahi-service-type))
10990 @unnumberedsubsec Instantiating the System
10992 Assuming the @code{operating-system} declaration
10993 is stored in the @file{my-system-config.scm}
10994 file, the @command{guix system reconfigure my-system-config.scm} command
10995 instantiates that configuration, and makes it the default GRUB boot
10996 entry (@pxref{Invoking guix system}).
10998 The normal way to change the system configuration is by updating this
10999 file and re-running @command{guix system reconfigure}. One should never
11000 have to touch files in @file{/etc} or to run commands that modify the
11001 system state such as @command{useradd} or @command{grub-install}. In
11002 fact, you must avoid that since that would not only void your warranty
11003 but also prevent you from rolling back to previous versions of your
11004 system, should you ever need to.
11006 @cindex roll-back, of the operating system
11007 Speaking of roll-back, each time you run @command{guix system
11008 reconfigure}, a new @dfn{generation} of the system is created---without
11009 modifying or deleting previous generations. Old system generations get
11010 an entry in the bootloader boot menu, allowing you to boot them in case
11011 something went wrong with the latest generation. Reassuring, no? The
11012 @command{guix system list-generations} command lists the system
11013 generations available on disk. It is also possible to roll back the
11014 system via the commands @command{guix system roll-back} and
11015 @command{guix system switch-generation}.
11017 Although the @command{guix system reconfigure} command will not modify
11018 previous generations, you must take care when the current generation is not
11019 the latest (e.g., after invoking @command{guix system roll-back}), since
11020 the operation might overwrite a later generation (@pxref{Invoking guix
11023 @unnumberedsubsec The Programming Interface
11025 At the Scheme level, the bulk of an @code{operating-system} declaration
11026 is instantiated with the following monadic procedure (@pxref{The Store
11029 @deffn {Monadic Procedure} operating-system-derivation os
11030 Return a derivation that builds @var{os}, an @code{operating-system}
11031 object (@pxref{Derivations}).
11033 The output of the derivation is a single directory that refers to all
11034 the packages, configuration files, and other supporting files needed to
11035 instantiate @var{os}.
11038 This procedure is provided by the @code{(gnu system)} module. Along
11039 with @code{(gnu services)} (@pxref{Services}), this module contains the
11040 guts of Guix System. Make sure to visit it!
11043 @node operating-system Reference
11044 @section @code{operating-system} Reference
11046 This section summarizes all the options available in
11047 @code{operating-system} declarations (@pxref{Using the Configuration
11050 @deftp {Data Type} operating-system
11051 This is the data type representing an operating system configuration.
11052 By that, we mean all the global system configuration, not per-user
11053 configuration (@pxref{Using the Configuration System}).
11056 @item @code{kernel} (default: @var{linux-libre})
11057 The package object of the operating system kernel to use@footnote{Currently
11058 only the Linux-libre kernel is supported. In the future, it will be
11059 possible to use the GNU@tie{}Hurd.}.
11061 @item @code{kernel-arguments} (default: @code{'("quiet")})
11062 List of strings or gexps representing additional arguments to pass on
11063 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11065 @item @code{bootloader}
11066 The system bootloader configuration object. @xref{Bootloader Configuration}.
11069 This is the label (a string) as it appears in the bootloader's menu entry.
11070 The default label includes the kernel name and version.
11072 @item @code{keyboard-layout} (default: @code{#f})
11073 This field specifies the keyboard layout to use in the console. It can be
11074 either @code{#f}, in which case the default keyboard layout is used (usually
11075 US English), or a @code{<keyboard-layout>} record.
11077 This keyboard layout is in effect as soon as the kernel has booted. For
11078 instance, it is the keyboard layout in effect when you type a passphrase if
11079 your root file system is on a @code{luks-device-mapping} mapped device
11080 (@pxref{Mapped Devices}).
11083 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11084 that used by the graphical display server. @xref{Bootloader Configuration},
11085 for information on how to specify the bootloader's keyboard layout. @xref{X
11086 Window}, for information on how to specify the keyboard layout used by the X
11090 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11092 @cindex initial RAM disk
11093 The list of Linux kernel modules that need to be available in the
11094 initial RAM disk. @xref{Initial RAM Disk}.
11096 @item @code{initrd} (default: @code{base-initrd})
11097 A procedure that returns an initial RAM disk for the Linux
11098 kernel. This field is provided to support low-level customization and
11099 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11101 @item @code{firmware} (default: @code{%base-firmware})
11103 List of firmware packages loadable by the operating system kernel.
11105 The default includes firmware needed for Atheros- and Broadcom-based
11106 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11107 respectively). @xref{Hardware Considerations}, for more info on
11108 supported hardware.
11110 @item @code{host-name}
11113 @item @code{hosts-file}
11115 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11116 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11117 Reference Manual}). The default is a file with entries for
11118 @code{localhost} and @var{host-name}.
11120 @item @code{mapped-devices} (default: @code{'()})
11121 A list of mapped devices. @xref{Mapped Devices}.
11123 @item @code{file-systems}
11124 A list of file systems. @xref{File Systems}.
11126 @item @code{swap-devices} (default: @code{'()})
11127 @cindex swap devices
11128 A list of strings identifying devices or files to be used for ``swap
11129 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11130 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11131 It is possible to specify a swap file in a file system on a mapped
11132 device, provided that the necessary device mapping and file system are
11133 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11135 @item @code{users} (default: @code{%base-user-accounts})
11136 @itemx @code{groups} (default: @code{%base-groups})
11137 List of user accounts and groups. @xref{User Accounts}.
11139 If the @code{users} list lacks a user account with UID@tie{}0, a
11140 ``root'' account with UID@tie{}0 is automatically added.
11142 @item @code{skeletons} (default: @code{(default-skeletons)})
11143 A list target file name/file-like object tuples (@pxref{G-Expressions,
11144 file-like objects}). These are the skeleton files that will be added to
11145 the home directory of newly-created user accounts.
11147 For instance, a valid value may look like this:
11150 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11151 (".guile" ,(plain-file "guile"
11152 "(use-modules (ice-9 readline))
11153 (activate-readline)")))
11156 @item @code{issue} (default: @code{%default-issue})
11157 A string denoting the contents of the @file{/etc/issue} file, which is
11158 displayed when users log in on a text console.
11160 @item @code{packages} (default: @code{%base-packages})
11161 The set of packages installed in the global profile, which is accessible
11162 at @file{/run/current-system/profile}.
11164 The default set includes core utilities and it is good practice to
11165 install non-core utilities in user profiles (@pxref{Invoking guix
11168 @item @code{timezone}
11169 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11171 You can run the @command{tzselect} command to find out which timezone
11172 string corresponds to your region. Choosing an invalid timezone name
11173 causes @command{guix system} to fail.
11175 @item @code{locale} (default: @code{"en_US.utf8"})
11176 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11177 Library Reference Manual}). @xref{Locales}, for more information.
11179 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11180 The list of locale definitions to be compiled and that may be used at
11181 run time. @xref{Locales}.
11183 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11184 The list of GNU@tie{}libc packages whose locale data and tools are used
11185 to build the locale definitions. @xref{Locales}, for compatibility
11186 considerations that justify this option.
11188 @item @code{name-service-switch} (default: @code{%default-nss})
11189 Configuration of the libc name service switch (NSS)---a
11190 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11193 @item @code{services} (default: @code{%base-services})
11194 A list of service objects denoting system services. @xref{Services}.
11196 @cindex essential services
11197 @item @code{essential-services} (default: ...)
11198 The list of ``essential services''---i.e., things like instances of
11199 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11200 Reference}), which are derived from the operating system definition itself.
11201 As a user you should @emph{never} need to touch this field.
11203 @item @code{pam-services} (default: @code{(base-pam-services)})
11205 @cindex pluggable authentication modules
11206 Linux @dfn{pluggable authentication module} (PAM) services.
11207 @c FIXME: Add xref to PAM services section.
11209 @item @code{setuid-programs} (default: @var{%setuid-programs})
11210 List of string-valued G-expressions denoting setuid programs.
11211 @xref{Setuid Programs}.
11213 @item @code{sudoers-file} (default: @var{%sudoers-specification})
11214 @cindex sudoers file
11215 The contents of the @file{/etc/sudoers} file as a file-like object
11216 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11218 This file specifies which users can use the @command{sudo} command, what
11219 they are allowed to do, and what privileges they may gain. The default
11220 is that only @code{root} and members of the @code{wheel} group may use
11225 @deffn {Scheme Syntax} this-operating-system
11226 When used in the @emph{lexical scope} of an operating system field definition,
11227 this identifier resolves to the operating system being defined.
11229 The example below shows how to refer to the operating system being defined in
11230 the definition of the @code{label} field:
11233 (use-modules (gnu) (guix))
11237 (label (package-full-name
11238 (operating-system-kernel this-operating-system))))
11241 It is an error to refer to @code{this-operating-system} outside an operating
11248 @section File Systems
11250 The list of file systems to be mounted is specified in the
11251 @code{file-systems} field of the operating system declaration
11252 (@pxref{Using the Configuration System}). Each file system is declared
11253 using the @code{file-system} form, like this:
11257 (mount-point "/home")
11258 (device "/dev/sda3")
11262 As usual, some of the fields are mandatory---those shown in the example
11263 above---while others can be omitted. These are described below.
11265 @deftp {Data Type} file-system
11266 Objects of this type represent file systems to be mounted. They
11267 contain the following members:
11271 This is a string specifying the type of the file system---e.g.,
11274 @item @code{mount-point}
11275 This designates the place where the file system is to be mounted.
11277 @item @code{device}
11278 This names the ``source'' of the file system. It can be one of three
11279 things: a file system label, a file system UUID, or the name of a
11280 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11281 systems without having to hard-code their actual device
11282 name@footnote{Note that, while it is tempting to use
11283 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11284 result, this is not recommended: These special device nodes are created
11285 by the udev daemon and may be unavailable at the time the device is
11288 @findex file-system-label
11289 File system labels are created using the @code{file-system-label}
11290 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11291 plain strings. Here's an example of a file system referred to by its
11292 label, as shown by the @command{e2label} command:
11296 (mount-point "/home")
11298 (device (file-system-label "my-home")))
11302 UUIDs are converted from their string representation (as shown by the
11303 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11304 @code{uuid} form expects 16-byte UUIDs as defined in
11305 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11306 form of UUID used by the ext2 family of file systems and others, but it
11307 is different from ``UUIDs'' found in FAT file systems, for instance.},
11312 (mount-point "/home")
11314 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11317 When the source of a file system is a mapped device (@pxref{Mapped
11318 Devices}), its @code{device} field @emph{must} refer to the mapped
11319 device name---e.g., @file{"/dev/mapper/root-partition"}.
11320 This is required so that
11321 the system knows that mounting the file system depends on having the
11322 corresponding device mapping established.
11324 @item @code{flags} (default: @code{'()})
11325 This is a list of symbols denoting mount flags. Recognized flags
11326 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11327 access to special files), @code{no-suid} (ignore setuid and setgid
11328 bits), @code{no-atime} (do not update file access times),
11329 @code{strict-atime} (update file access time), @code{lazy-time} (only
11330 update time on the in-memory version of the file inode), and
11331 @code{no-exec} (disallow program execution).
11332 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
11333 Manual}, for more information on these flags.
11335 @item @code{options} (default: @code{#f})
11336 This is either @code{#f}, or a string denoting mount options passed to the
11337 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11338 Reference Manual}, for details and run @command{man 8 mount} for options for
11339 various file systems.
11341 @item @code{mount?} (default: @code{#t})
11342 This value indicates whether to automatically mount the file system when
11343 the system is brought up. When set to @code{#f}, the file system gets
11344 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11345 is not automatically mounted.
11347 @item @code{needed-for-boot?} (default: @code{#f})
11348 This Boolean value indicates whether the file system is needed when
11349 booting. If that is true, then the file system is mounted when the
11350 initial RAM disk (initrd) is loaded. This is always the case, for
11351 instance, for the root file system.
11353 @item @code{check?} (default: @code{#t})
11354 This Boolean indicates whether the file system needs to be checked for
11355 errors before being mounted.
11357 @item @code{create-mount-point?} (default: @code{#f})
11358 When true, the mount point is created if it does not exist yet.
11360 @item @code{dependencies} (default: @code{'()})
11361 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11362 representing file systems that must be mounted or mapped devices that
11363 must be opened before (and unmounted or closed after) this one.
11365 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11366 a dependency of @file{/sys/fs/cgroup/cpu} and
11367 @file{/sys/fs/cgroup/memory}.
11369 Another example is a file system that depends on a mapped device, for
11370 example for an encrypted partition (@pxref{Mapped Devices}).
11374 The @code{(gnu system file-systems)} exports the following useful
11377 @defvr {Scheme Variable} %base-file-systems
11378 These are essential file systems that are required on normal systems,
11379 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
11380 below.) Operating system declarations should always contain at least
11384 @defvr {Scheme Variable} %pseudo-terminal-file-system
11385 This is the file system to be mounted as @file{/dev/pts}. It supports
11386 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11387 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11388 Manual}). Pseudo-terminals are used by terminal emulators such as
11392 @defvr {Scheme Variable} %shared-memory-file-system
11393 This file system is mounted as @file{/dev/shm} and is used to support
11394 memory sharing across processes (@pxref{Memory-mapped I/O,
11395 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11398 @defvr {Scheme Variable} %immutable-store
11399 This file system performs a read-only ``bind mount'' of
11400 @file{/gnu/store}, making it read-only for all the users including
11401 @code{root}. This prevents against accidental modification by software
11402 running as @code{root} or by system administrators.
11404 The daemon itself is still able to write to the store: it remounts it
11405 read-write in its own ``name space.''
11408 @defvr {Scheme Variable} %binary-format-file-system
11409 The @code{binfmt_misc} file system, which allows handling of arbitrary
11410 executable file types to be delegated to user space. This requires the
11411 @code{binfmt.ko} kernel module to be loaded.
11414 @defvr {Scheme Variable} %fuse-control-file-system
11415 The @code{fusectl} file system, which allows unprivileged users to mount
11416 and unmount user-space FUSE file systems. This requires the
11417 @code{fuse.ko} kernel module to be loaded.
11420 @node Mapped Devices
11421 @section Mapped Devices
11423 @cindex device mapping
11424 @cindex mapped devices
11425 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11426 such as a hard disk partition, can be @dfn{mapped} into another device,
11427 usually in @code{/dev/mapper/},
11428 with additional processing over the data that flows through
11429 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11430 concept of a ``mapped device'' and that of a file system: both boil down
11431 to @emph{translating} input/output operations made on a file to
11432 operations on its backing store. Thus, the Hurd implements mapped
11433 devices, like file systems, using the generic @dfn{translator} mechanism
11434 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11435 typical example is encryption device mapping: all writes to the mapped
11436 device are encrypted, and all reads are deciphered, transparently.
11437 Guix extends this notion by considering any device or set of devices that
11438 are @dfn{transformed} in some way to create a new device; for instance,
11439 RAID devices are obtained by @dfn{assembling} several other devices, such
11440 as hard disks or partitions, into a new one that behaves as one partition.
11441 Other examples, not yet implemented, are LVM logical volumes.
11443 Mapped devices are declared using the @code{mapped-device} form,
11444 defined as follows; for examples, see below.
11446 @deftp {Data Type} mapped-device
11447 Objects of this type represent device mappings that will be made when
11448 the system boots up.
11452 This is either a string specifying the name of the block device to be mapped,
11453 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11454 need to be assembled for creating a new one.
11457 This string specifies the name of the resulting mapped device. For
11458 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11459 specifying @code{"my-partition"} leads to the creation of
11460 the @code{"/dev/mapper/my-partition"} device.
11461 For RAID devices of type @code{raid-device-mapping}, the full device name
11462 such as @code{"/dev/md0"} needs to be given.
11465 This must be a @code{mapped-device-kind} object, which specifies how
11466 @var{source} is mapped to @var{target}.
11470 @defvr {Scheme Variable} luks-device-mapping
11471 This defines LUKS block device encryption using the @command{cryptsetup}
11472 command from the package with the same name. It relies on the
11473 @code{dm-crypt} Linux kernel module.
11476 @defvr {Scheme Variable} raid-device-mapping
11477 This defines a RAID device, which is assembled using the @code{mdadm}
11478 command from the package with the same name. It requires a Linux kernel
11479 module for the appropriate RAID level to be loaded, such as @code{raid456}
11480 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11483 @cindex disk encryption
11485 The following example specifies a mapping from @file{/dev/sda3} to
11486 @file{/dev/mapper/home} using LUKS---the
11487 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11488 standard mechanism for disk encryption.
11489 The @file{/dev/mapper/home}
11490 device can then be used as the @code{device} of a @code{file-system}
11491 declaration (@pxref{File Systems}).
11495 (source "/dev/sda3")
11497 (type luks-device-mapping))
11500 Alternatively, to become independent of device numbering, one may obtain
11501 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11505 cryptsetup luksUUID /dev/sda3
11508 and use it as follows:
11512 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11514 (type luks-device-mapping))
11517 @cindex swap encryption
11518 It is also desirable to encrypt swap space, since swap space may contain
11519 sensitive data. One way to accomplish that is to use a swap file in a
11520 file system on a device mapped via LUKS encryption. In this way, the
11521 swap file is encrypted because the entire device is encrypted.
11522 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11524 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11525 may be declared as follows:
11529 (source (list "/dev/sda1" "/dev/sdb1"))
11530 (target "/dev/md0")
11531 (type raid-device-mapping))
11534 The @file{/dev/md0} device can then be used as the @code{device} of a
11535 @code{file-system} declaration (@pxref{File Systems}).
11536 Note that the RAID level need not be given; it is chosen during the
11537 initial creation and formatting of the RAID device and is determined
11538 automatically later.
11541 @node User Accounts
11542 @section User Accounts
11546 @cindex user accounts
11547 User accounts and groups are entirely managed through the
11548 @code{operating-system} declaration. They are specified with the
11549 @code{user-account} and @code{user-group} forms:
11555 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11556 "audio" ;sound card
11557 "video" ;video devices such as webcams
11558 "cdrom")) ;the good ol' CD-ROM
11559 (comment "Bob's sister")
11560 (home-directory "/home/alice"))
11563 When booting or upon completion of @command{guix system reconfigure},
11564 the system ensures that only the user accounts and groups specified in
11565 the @code{operating-system} declaration exist, and with the specified
11566 properties. Thus, account or group creations or modifications made by
11567 directly invoking commands such as @command{useradd} are lost upon
11568 reconfiguration or reboot. This ensures that the system remains exactly
11571 @deftp {Data Type} user-account
11572 Objects of this type represent user accounts. The following members may
11577 The name of the user account.
11581 This is the name (a string) or identifier (a number) of the user group
11582 this account belongs to.
11584 @item @code{supplementary-groups} (default: @code{'()})
11585 Optionally, this can be defined as a list of group names that this
11586 account belongs to.
11588 @item @code{uid} (default: @code{#f})
11589 This is the user ID for this account (a number), or @code{#f}. In the
11590 latter case, a number is automatically chosen by the system when the
11591 account is created.
11593 @item @code{comment} (default: @code{""})
11594 A comment about the account, such as the account owner's full name.
11596 @item @code{home-directory}
11597 This is the name of the home directory for the account.
11599 @item @code{create-home-directory?} (default: @code{#t})
11600 Indicates whether the home directory of this account should be created
11601 if it does not exist yet.
11603 @item @code{shell} (default: Bash)
11604 This is a G-expression denoting the file name of a program to be used as
11605 the shell (@pxref{G-Expressions}).
11607 @item @code{system?} (default: @code{#f})
11608 This Boolean value indicates whether the account is a ``system''
11609 account. System accounts are sometimes treated specially; for instance,
11610 graphical login managers do not list them.
11612 @anchor{user-account-password}
11613 @cindex password, for user accounts
11614 @item @code{password} (default: @code{#f})
11615 You would normally leave this field to @code{#f}, initialize user
11616 passwords as @code{root} with the @command{passwd} command, and then let
11617 users change it with @command{passwd}. Passwords set with
11618 @command{passwd} are of course preserved across reboot and
11621 If you @emph{do} want to set an initial password for an account, then
11622 this field must contain the encrypted password, as a string. You can use the
11623 @code{crypt} procedure for this purpose:
11630 ;; Specify a SHA-512-hashed initial password.
11631 (password (crypt "InitialPassword!" "$6$abc")))
11635 The hash of this initial password will be available in a file in
11636 @file{/gnu/store}, readable by all the users, so this method must be used with
11640 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11641 more information on password encryption, and @ref{Encryption,,, guile, GNU
11642 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11648 User group declarations are even simpler:
11651 (user-group (name "students"))
11654 @deftp {Data Type} user-group
11655 This type is for, well, user groups. There are just a few fields:
11659 The name of the group.
11661 @item @code{id} (default: @code{#f})
11662 The group identifier (a number). If @code{#f}, a new number is
11663 automatically allocated when the group is created.
11665 @item @code{system?} (default: @code{#f})
11666 This Boolean value indicates whether the group is a ``system'' group.
11667 System groups have low numerical IDs.
11669 @item @code{password} (default: @code{#f})
11670 What, user groups can have a password? Well, apparently yes. Unless
11671 @code{#f}, this field specifies the password of the group.
11676 For convenience, a variable lists all the basic user groups one may
11679 @defvr {Scheme Variable} %base-groups
11680 This is the list of basic user groups that users and/or packages expect
11681 to be present on the system. This includes groups such as ``root'',
11682 ``wheel'', and ``users'', as well as groups used to control access to
11683 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11686 @defvr {Scheme Variable} %base-user-accounts
11687 This is the list of basic system accounts that programs may expect to
11688 find on a GNU/Linux system, such as the ``nobody'' account.
11690 Note that the ``root'' account is not included here. It is a
11691 special-case and is automatically added whether or not it is specified.
11694 @node Keyboard Layout
11695 @section Keyboard Layout
11697 @cindex keyboard layout
11699 To specify what each key of your keyboard does, you need to tell the operating
11700 system what @dfn{keyboard layout} you want to use. The default, when nothing
11701 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11702 However, German speakers will usually prefer the German QWERTZ layout, French
11703 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11704 or bépo, and they might even want to further customize the effect of some of
11705 the keys. This section explains how to get that done.
11707 @cindex keyboard layout, definition
11708 There are three components that will want to know about your keyboard layout:
11712 The @emph{bootloader} may want to know what keyboard layout you want to use
11713 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11714 you want, for instance, to make sure that you can type the passphrase of your
11715 encrypted root partition using the right layout.
11718 The @emph{operating system kernel}, Linux, will need that so that the console
11719 is properly configured (@pxref{operating-system Reference,
11720 @code{keyboard-layout}}).
11723 The @emph{graphical display server}, usually Xorg, also has its own idea of
11724 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11727 Guix allows you to configure all three separately but, fortunately, it allows
11728 you to share the same keyboard layout for all three components.
11730 @cindex XKB, keyboard layouts
11731 Keyboard layouts are represented by records created by the
11732 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11733 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11734 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11735 optional variant name, an optional keyboard model name, and a possibly empty
11736 list of additional options. In most cases the layout name is all you care
11737 about. Here are a few example:
11740 ;; The German QWERTZ layout. Here we assume a standard
11741 ;; "pc105" keyboard model.
11742 (keyboard-layout "de")
11744 ;; The bépo variant of the French layout.
11745 (keyboard-layout "fr" "bepo")
11747 ;; The Catalan layout.
11748 (keyboard-layout "es" "cat")
11750 ;; The Latin American Spanish layout. In addition, the
11751 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11752 ;; and the "Menu" key is used as a "Compose" key to enter
11753 ;; accented letters.
11754 (keyboard-layout "latam"
11755 #:options '("ctrl:nocaps" "compose:menu"))
11757 ;; The Russian layout for a ThinkPad keyboard.
11758 (keyboard-layout "ru" #:model "thinkpad")
11760 ;; The "US international" layout, which is the US layout plus
11761 ;; dead keys to enter accented characters. This is for an
11762 ;; Apple MacBook keyboard.
11763 (keyboard-layout "us" "intl" #:model "macbook78")
11766 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11767 for a complete list of supported layouts, variants, and models.
11769 @cindex keyboard layout, configuration
11770 Let's say you want your system to use the Turkish keyboard layout throughout
11771 your system---bootloader, console, and Xorg. Here's what your system
11772 configuration would look like:
11774 @findex set-xorg-configuration
11776 ;; Using the Turkish layout for the bootloader, the console,
11781 (keyboard-layout (keyboard-layout "tr")) ;for the console
11782 (bootloader (bootloader-configuration
11783 (bootloader grub-efi-bootloader)
11784 (target "/boot/efi")
11785 (keyboard-layout keyboard-layout))) ;for GRUB
11786 (services (cons (set-xorg-configuration
11787 (xorg-configuration ;for Xorg
11788 (keyboard-layout keyboard-layout)))
11789 %desktop-services)))
11792 In the example above, for GRUB and for Xorg, we just refer to the
11793 @code{keyboard-layout} field defined above, but we could just as well refer to
11794 a different layout. The @code{set-xorg-configuration} procedure communicates
11795 the desired Xorg configuration to the graphical log-in manager, by default
11798 We've discussed how to specify the @emph{default} keyboard layout of your
11799 system when it starts, but you can also adjust it at run time:
11803 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11804 where you can select one or more keyboard layouts.
11807 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11808 allows you to change the current layout. For example, this is how you would
11809 change the layout to US Dvorak:
11812 setxkbmap us dvorak
11816 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11817 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11818 keyboard layout categorization described above. The command below loads the
11819 French bépo layout:
11830 A @dfn{locale} defines cultural conventions for a particular language
11831 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11832 Reference Manual}). Each locale has a name that typically has the form
11833 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11834 @code{fr_LU.utf8} designates the locale for the French language, with
11835 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11837 @cindex locale definition
11838 Usually, you will want to specify the default locale for the machine
11839 using the @code{locale} field of the @code{operating-system} declaration
11840 (@pxref{operating-system Reference, @code{locale}}).
11842 The selected locale is automatically added to the @dfn{locale
11843 definitions} known to the system if needed, with its codeset inferred
11844 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11845 @code{UTF-8} codeset. Additional locale definitions can be specified in
11846 the @code{locale-definitions} slot of @code{operating-system}---this is
11847 useful, for instance, if the codeset could not be inferred from the
11848 locale name. The default set of locale definitions includes some widely
11849 used locales, but not all the available locales, in order to save space.
11851 For instance, to add the North Frisian locale for Germany, the value of
11855 (cons (locale-definition
11856 (name "fy_DE.utf8") (source "fy_DE"))
11857 %default-locale-definitions)
11860 Likewise, to save space, one might want @code{locale-definitions} to
11861 list only the locales that are actually used, as in:
11864 (list (locale-definition
11865 (name "ja_JP.eucjp") (source "ja_JP")
11866 (charset "EUC-JP")))
11870 The compiled locale definitions are available at
11871 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11872 version, which is the default location where the GNU@tie{}libc provided
11873 by Guix looks for locale data. This can be overridden using the
11874 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11875 @code{LOCPATH} and locale packages}).
11877 The @code{locale-definition} form is provided by the @code{(gnu system
11878 locale)} module. Details are given below.
11880 @deftp {Data Type} locale-definition
11881 This is the data type of a locale definition.
11886 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11887 Reference Manual}, for more information on locale names.
11889 @item @code{source}
11890 The name of the source for that locale. This is typically the
11891 @code{@var{language}_@var{territory}} part of the locale name.
11893 @item @code{charset} (default: @code{"UTF-8"})
11894 The ``character set'' or ``code set'' for that locale,
11895 @uref{https://www.iana.org/assignments/character-sets, as defined by
11901 @defvr {Scheme Variable} %default-locale-definitions
11902 A list of commonly used UTF-8 locales, used as the default
11903 value of the @code{locale-definitions} field of @code{operating-system}
11906 @cindex locale name
11907 @cindex normalized codeset in locale names
11908 These locale definitions use the @dfn{normalized codeset} for the part
11909 that follows the dot in the name (@pxref{Using gettextized software,
11910 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11911 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11912 @code{uk_UA.UTF-8}.
11915 @subsection Locale Data Compatibility Considerations
11917 @cindex incompatibility, of locale data
11918 @code{operating-system} declarations provide a @code{locale-libcs} field
11919 to specify the GNU@tie{}libc packages that are used to compile locale
11920 declarations (@pxref{operating-system Reference}). ``Why would I
11921 care?'', you may ask. Well, it turns out that the binary format of
11922 locale data is occasionally incompatible from one libc version to
11925 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11926 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11927 For instance, a program linked against libc version 2.21 is unable to
11928 read locale data produced with libc 2.22; worse, that program
11929 @emph{aborts} instead of simply ignoring the incompatible locale
11930 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11931 the incompatible locale data, which is already an improvement.}.
11932 Similarly, a program linked against libc 2.22 can read most, but not
11933 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11934 data is incompatible); thus calls to @code{setlocale} may fail, but
11935 programs will not abort.
11937 The ``problem'' with Guix is that users have a lot of freedom: They can
11938 choose whether and when to upgrade software in their profiles, and might
11939 be using a libc version different from the one the system administrator
11940 used to build the system-wide locale data.
11942 Fortunately, unprivileged users can also install their own locale data
11943 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11944 @code{GUIX_LOCPATH} and locale packages}).
11946 Still, it is best if the system-wide locale data at
11947 @file{/run/current-system/locale} is built for all the libc versions
11948 actually in use on the system, so that all the programs can access
11949 it---this is especially crucial on a multi-user system. To do that, the
11950 administrator can specify several libc packages in the
11951 @code{locale-libcs} field of @code{operating-system}:
11954 (use-package-modules base)
11958 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11961 This example would lead to a system containing locale definitions for
11962 both libc 2.21 and the current version of libc in
11963 @file{/run/current-system/locale}.
11969 @cindex system services
11970 An important part of preparing an @code{operating-system} declaration is
11971 listing @dfn{system services} and their configuration (@pxref{Using the
11972 Configuration System}). System services are typically daemons launched
11973 when the system boots, or other actions needed at that time---e.g.,
11974 configuring network access.
11976 Guix has a broad definition of ``service'' (@pxref{Service
11977 Composition}), but many services are managed by the GNU@tie{}Shepherd
11978 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11979 command allows you to list the available services, show their status,
11980 start and stop them, or do other specific operations (@pxref{Jump
11981 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11987 The above command, run as @code{root}, lists the currently defined
11988 services. The @command{herd doc} command shows a synopsis of the given
11989 service and its associated actions:
11993 Run libc's name service cache daemon (nscd).
11995 # herd doc nscd action invalidate
11996 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11999 The @command{start}, @command{stop}, and @command{restart} sub-commands
12000 have the effect you would expect. For instance, the commands below stop
12001 the nscd service and restart the Xorg display server:
12005 Service nscd has been stopped.
12006 # herd restart xorg-server
12007 Service xorg-server has been stopped.
12008 Service xorg-server has been started.
12011 The following sections document the available services, starting with
12012 the core services, that may be used in an @code{operating-system}
12016 * Base Services:: Essential system services.
12017 * Scheduled Job Execution:: The mcron service.
12018 * Log Rotation:: The rottlog service.
12019 * Networking Services:: Network setup, SSH daemon, etc.
12020 * X Window:: Graphical display.
12021 * Printing Services:: Local and remote printer support.
12022 * Desktop Services:: D-Bus and desktop services.
12023 * Sound Services:: ALSA and Pulseaudio services.
12024 * Database Services:: SQL databases, key-value stores, etc.
12025 * Mail Services:: IMAP, POP3, SMTP, and all that.
12026 * Messaging Services:: Messaging services.
12027 * Telephony Services:: Telephony services.
12028 * Monitoring Services:: Monitoring services.
12029 * Kerberos Services:: Kerberos services.
12030 * LDAP Services:: LDAP services.
12031 * Web Services:: Web servers.
12032 * Certificate Services:: TLS certificates via Let's Encrypt.
12033 * DNS Services:: DNS daemons.
12034 * VPN Services:: VPN daemons.
12035 * Network File System:: NFS related services.
12036 * Continuous Integration:: The Cuirass service.
12037 * Power Management Services:: Extending battery life.
12038 * Audio Services:: The MPD.
12039 * Virtualization Services:: Virtualization services.
12040 * Version Control Services:: Providing remote access to Git repositories.
12041 * Game Services:: Game servers.
12042 * PAM Mount Service:: Service to mount volumes when logging in.
12043 * Guix Services:: Services relating specifically to Guix.
12044 * Miscellaneous Services:: Other services.
12047 @node Base Services
12048 @subsection Base Services
12050 The @code{(gnu services base)} module provides definitions for the basic
12051 services that one expects from the system. The services exported by
12052 this module are listed below.
12054 @defvr {Scheme Variable} %base-services
12055 This variable contains a list of basic services (@pxref{Service Types
12056 and Services}, for more information on service objects) one would
12057 expect from the system: a login service (mingetty) on each tty, syslogd,
12058 the libc name service cache daemon (nscd), the udev device manager, and
12061 This is the default value of the @code{services} field of
12062 @code{operating-system} declarations. Usually, when customizing a
12063 system, you will want to append services to @code{%base-services}, like
12067 (append (list (service avahi-service-type)
12068 (service openssh-service-type))
12073 @defvr {Scheme Variable} special-files-service-type
12074 This is the service that sets up ``special files'' such as
12075 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12077 The value associated with @code{special-files-service-type} services
12078 must be a list of tuples where the first element is the ``special file''
12079 and the second element is its target. By default it is:
12081 @cindex @file{/bin/sh}
12082 @cindex @file{sh}, in @file{/bin}
12084 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12087 @cindex @file{/usr/bin/env}
12088 @cindex @file{env}, in @file{/usr/bin}
12089 If you want to add, say, @code{/usr/bin/env} to your system, you can
12093 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12094 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12097 Since this is part of @code{%base-services}, you can use
12098 @code{modify-services} to customize the set of special files
12099 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12100 to add a special file is @i{via} the @code{extra-special-file} procedure
12104 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12105 Use @var{target} as the ``special file'' @var{file}.
12107 For example, adding the following lines to the @code{services} field of
12108 your operating system declaration leads to a @file{/usr/bin/env}
12112 (extra-special-file "/usr/bin/env"
12113 (file-append coreutils "/bin/env"))
12117 @deffn {Scheme Procedure} host-name-service @var{name}
12118 Return a service that sets the host name to @var{name}.
12121 @deffn {Scheme Procedure} login-service @var{config}
12122 Return a service to run login according to @var{config}, a
12123 @code{<login-configuration>} object, which specifies the message of the day,
12124 among other things.
12127 @deftp {Data Type} login-configuration
12128 This is the data type representing the configuration of login.
12133 @cindex message of the day
12134 A file-like object containing the ``message of the day''.
12136 @item @code{allow-empty-passwords?} (default: @code{#t})
12137 Allow empty passwords by default so that first-time users can log in when
12138 the 'root' account has just been created.
12143 @deffn {Scheme Procedure} mingetty-service @var{config}
12144 Return a service to run mingetty according to @var{config}, a
12145 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12149 @deftp {Data Type} mingetty-configuration
12150 This is the data type representing the configuration of Mingetty, which
12151 provides the default implementation of virtual console log-in.
12156 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12158 @item @code{auto-login} (default: @code{#f})
12159 When true, this field must be a string denoting the user name under
12160 which the system automatically logs in. When it is @code{#f}, a
12161 user name and password must be entered to log in.
12163 @item @code{login-program} (default: @code{#f})
12164 This must be either @code{#f}, in which case the default log-in program
12165 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12166 the name of the log-in program.
12168 @item @code{login-pause?} (default: @code{#f})
12169 When set to @code{#t} in conjunction with @var{auto-login}, the user
12170 will have to press a key before the log-in shell is launched.
12172 @item @code{mingetty} (default: @var{mingetty})
12173 The Mingetty package to use.
12178 @deffn {Scheme Procedure} agetty-service @var{config}
12179 Return a service to run agetty according to @var{config}, an
12180 @code{<agetty-configuration>} object, which specifies the tty to run,
12181 among other things.
12184 @deftp {Data Type} agetty-configuration
12185 This is the data type representing the configuration of agetty, which
12186 implements virtual and serial console log-in. See the @code{agetty(8)}
12187 man page for more information.
12192 The name of the console this agetty runs on, as a string---e.g.,
12193 @code{"ttyS0"}. This argument is optional, it will default to
12194 a reasonable default serial port used by the kernel Linux.
12196 For this, if there is a value for an option @code{agetty.tty} in the kernel
12197 command line, agetty will extract the device name of the serial port
12198 from it and use that.
12200 If not and if there is a value for an option @code{console} with a tty in
12201 the Linux command line, agetty will extract the device name of the
12202 serial port from it and use that.
12204 In both cases, agetty will leave the other serial device settings
12205 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12208 @item @code{baud-rate} (default: @code{#f})
12209 A string containing a comma-separated list of one or more baud rates, in
12212 @item @code{term} (default: @code{#f})
12213 A string containing the value used for the @code{TERM} environment
12216 @item @code{eight-bits?} (default: @code{#f})
12217 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12220 @item @code{auto-login} (default: @code{#f})
12221 When passed a login name, as a string, the specified user will be logged
12222 in automatically without prompting for their login name or password.
12224 @item @code{no-reset?} (default: @code{#f})
12225 When @code{#t}, don't reset terminal cflags (control modes).
12227 @item @code{host} (default: @code{#f})
12228 This accepts a string containing the "login_host", which will be written
12229 into the @file{/var/run/utmpx} file.
12231 @item @code{remote?} (default: @code{#f})
12232 When set to @code{#t} in conjunction with @var{host}, this will add an
12233 @code{-r} fakehost option to the command line of the login program
12234 specified in @var{login-program}.
12236 @item @code{flow-control?} (default: @code{#f})
12237 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12239 @item @code{no-issue?} (default: @code{#f})
12240 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12241 not be displayed before presenting the login prompt.
12243 @item @code{init-string} (default: @code{#f})
12244 This accepts a string that will be sent to the tty or modem before
12245 sending anything else. It can be used to initialize a modem.
12247 @item @code{no-clear?} (default: @code{#f})
12248 When set to @code{#t}, agetty will not clear the screen before showing
12251 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12252 This must be either a gexp denoting the name of a log-in program, or
12253 unset, in which case the default value is the @command{login} from the
12256 @item @code{local-line} (default: @code{#f})
12257 Control the CLOCAL line flag. This accepts one of three symbols as
12258 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12259 the default value chosen by agetty is @code{'auto}.
12261 @item @code{extract-baud?} (default: @code{#f})
12262 When set to @code{#t}, instruct agetty to try to extract the baud rate
12263 from the status messages produced by certain types of modems.
12265 @item @code{skip-login?} (default: @code{#f})
12266 When set to @code{#t}, do not prompt the user for a login name. This
12267 can be used with @var{login-program} field to use non-standard login
12270 @item @code{no-newline?} (default: @code{#f})
12271 When set to @code{#t}, do not print a newline before printing the
12272 @file{/etc/issue} file.
12274 @c Is this dangerous only when used with login-program, or always?
12275 @item @code{login-options} (default: @code{#f})
12276 This option accepts a string containing options that are passed to the
12277 login program. When used with the @var{login-program}, be aware that a
12278 malicious user could try to enter a login name containing embedded
12279 options that could be parsed by the login program.
12281 @item @code{login-pause} (default: @code{#f})
12282 When set to @code{#t}, wait for any key before showing the login prompt.
12283 This can be used in conjunction with @var{auto-login} to save memory by
12284 lazily spawning shells.
12286 @item @code{chroot} (default: @code{#f})
12287 Change root to the specified directory. This option accepts a directory
12290 @item @code{hangup?} (default: @code{#f})
12291 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12292 specified terminal.
12294 @item @code{keep-baud?} (default: @code{#f})
12295 When set to @code{#t}, try to keep the existing baud rate. The baud
12296 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12299 @item @code{timeout} (default: @code{#f})
12300 When set to an integer value, terminate if no user name could be read
12301 within @var{timeout} seconds.
12303 @item @code{detect-case?} (default: @code{#f})
12304 When set to @code{#t}, turn on support for detecting an uppercase-only
12305 terminal. This setting will detect a login name containing only
12306 uppercase letters as indicating an uppercase-only terminal and turn on
12307 some upper-to-lower case conversions. Note that this will not support
12308 Unicode characters.
12310 @item @code{wait-cr?} (default: @code{#f})
12311 When set to @code{#t}, wait for the user or modem to send a
12312 carriage-return or linefeed character before displaying
12313 @file{/etc/issue} or login prompt. This is typically used with the
12314 @var{init-string} option.
12316 @item @code{no-hints?} (default: @code{#f})
12317 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12320 @item @code{no-hostname?} (default: @code{#f})
12321 By default, the hostname is printed. When this option is set to
12322 @code{#t}, no hostname will be shown at all.
12324 @item @code{long-hostname?} (default: @code{#f})
12325 By default, the hostname is only printed until the first dot. When this
12326 option is set to @code{#t}, the fully qualified hostname by
12327 @code{gethostname} or @code{getaddrinfo} is shown.
12329 @item @code{erase-characters} (default: @code{#f})
12330 This option accepts a string of additional characters that should be
12331 interpreted as backspace when the user types their login name.
12333 @item @code{kill-characters} (default: @code{#f})
12334 This option accepts a string that should be interpreted to mean "ignore
12335 all previous characters" (also called a "kill" character) when the user
12336 types their login name.
12338 @item @code{chdir} (default: @code{#f})
12339 This option accepts, as a string, a directory path that will be changed
12342 @item @code{delay} (default: @code{#f})
12343 This options accepts, as an integer, the number of seconds to sleep
12344 before opening the tty and displaying the login prompt.
12346 @item @code{nice} (default: @code{#f})
12347 This option accepts, as an integer, the nice value with which to run the
12348 @command{login} program.
12350 @item @code{extra-options} (default: @code{'()})
12351 This option provides an "escape hatch" for the user to provide arbitrary
12352 command-line arguments to @command{agetty} as a list of strings.
12357 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12358 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12359 according to @var{config}, a @code{<kmscon-configuration>} object, which
12360 specifies the tty to run, among other things.
12363 @deftp {Data Type} kmscon-configuration
12364 This is the data type representing the configuration of Kmscon, which
12365 implements virtual console log-in.
12369 @item @code{virtual-terminal}
12370 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12372 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12373 A gexp denoting the name of the log-in program. The default log-in program is
12374 @command{login} from the Shadow tool suite.
12376 @item @code{login-arguments} (default: @code{'("-p")})
12377 A list of arguments to pass to @command{login}.
12379 @item @code{auto-login} (default: @code{#f})
12380 When passed a login name, as a string, the specified user will be logged
12381 in automatically without prompting for their login name or password.
12383 @item @code{hardware-acceleration?} (default: #f)
12384 Whether to use hardware acceleration.
12386 @item @code{kmscon} (default: @var{kmscon})
12387 The Kmscon package to use.
12392 @cindex name service cache daemon
12394 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12395 [#:name-services '()]
12396 Return a service that runs the libc name service cache daemon (nscd) with the
12397 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12398 Service Switch}, for an example.
12400 For convenience, the Shepherd service for nscd provides the following actions:
12404 @cindex cache invalidation, nscd
12405 @cindex nscd, cache invalidation
12406 This invalidate the given cache. For instance, running:
12409 herd invalidate nscd hosts
12413 invalidates the host name lookup cache of nscd.
12416 Running @command{herd statistics nscd} displays information about nscd usage
12422 @defvr {Scheme Variable} %nscd-default-configuration
12423 This is the default @code{<nscd-configuration>} value (see below) used
12424 by @code{nscd-service}. It uses the caches defined by
12425 @var{%nscd-default-caches}; see below.
12428 @deftp {Data Type} nscd-configuration
12429 This is the data type representing the name service cache daemon (nscd)
12434 @item @code{name-services} (default: @code{'()})
12435 List of packages denoting @dfn{name services} that must be visible to
12436 the nscd---e.g., @code{(list @var{nss-mdns})}.
12438 @item @code{glibc} (default: @var{glibc})
12439 Package object denoting the GNU C Library providing the @command{nscd}
12442 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12443 Name of the nscd log file. This is where debugging output goes when
12444 @code{debug-level} is strictly positive.
12446 @item @code{debug-level} (default: @code{0})
12447 Integer denoting the debugging levels. Higher numbers mean that more
12448 debugging output is logged.
12450 @item @code{caches} (default: @var{%nscd-default-caches})
12451 List of @code{<nscd-cache>} objects denoting things to be cached; see
12457 @deftp {Data Type} nscd-cache
12458 Data type representing a cache database of nscd and its parameters.
12462 @item @code{database}
12463 This is a symbol representing the name of the database to be cached.
12464 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12465 @code{services}, which designate the corresponding NSS database
12466 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12468 @item @code{positive-time-to-live}
12469 @itemx @code{negative-time-to-live} (default: @code{20})
12470 A number representing the number of seconds during which a positive or
12471 negative lookup result remains in cache.
12473 @item @code{check-files?} (default: @code{#t})
12474 Whether to check for updates of the files corresponding to
12477 For instance, when @var{database} is @code{hosts}, setting this flag
12478 instructs nscd to check for updates in @file{/etc/hosts} and to take
12481 @item @code{persistent?} (default: @code{#t})
12482 Whether the cache should be stored persistently on disk.
12484 @item @code{shared?} (default: @code{#t})
12485 Whether the cache should be shared among users.
12487 @item @code{max-database-size} (default: 32@tie{}MiB)
12488 Maximum size in bytes of the database cache.
12490 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12491 @c settings, so leave them out.
12496 @defvr {Scheme Variable} %nscd-default-caches
12497 List of @code{<nscd-cache>} objects used by default by
12498 @code{nscd-configuration} (see above).
12500 It enables persistent and aggressive caching of service and host name
12501 lookups. The latter provides better host name lookup performance,
12502 resilience in the face of unreliable name servers, and also better
12503 privacy---often the result of host name lookups is in local cache, so
12504 external name servers do not even need to be queried.
12507 @anchor{syslog-configuration-type}
12510 @deftp {Data Type} syslog-configuration
12511 This data type represents the configuration of the syslog daemon.
12514 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12515 The syslog daemon to use.
12517 @item @code{config-file} (default: @code{%default-syslog.conf})
12518 The syslog configuration file to use.
12523 @anchor{syslog-service}
12525 @deffn {Scheme Procedure} syslog-service @var{config}
12526 Return a service that runs a syslog daemon according to @var{config}.
12528 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12529 information on the configuration file syntax.
12532 @defvr {Scheme Variable} guix-service-type
12533 This is the type of the service that runs the build daemon,
12534 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12535 @code{guix-configuration} record as described below.
12538 @anchor{guix-configuration-type}
12539 @deftp {Data Type} guix-configuration
12540 This data type represents the configuration of the Guix build daemon.
12541 @xref{Invoking guix-daemon}, for more information.
12544 @item @code{guix} (default: @var{guix})
12545 The Guix package to use.
12547 @item @code{build-group} (default: @code{"guixbuild"})
12548 Name of the group for build user accounts.
12550 @item @code{build-accounts} (default: @code{10})
12551 Number of build user accounts to create.
12553 @item @code{authorize-key?} (default: @code{#t})
12554 @cindex substitutes, authorization thereof
12555 Whether to authorize the substitute keys listed in
12556 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12557 (@pxref{Substitutes}).
12559 @vindex %default-authorized-guix-keys
12560 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12561 The list of authorized key files for archive imports, as a list of
12562 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12563 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12565 @item @code{use-substitutes?} (default: @code{#t})
12566 Whether to use substitutes.
12568 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12569 The list of URLs where to look for substitutes by default.
12571 @item @code{max-silent-time} (default: @code{0})
12572 @itemx @code{timeout} (default: @code{0})
12573 The number of seconds of silence and the number of seconds of activity,
12574 respectively, after which a build process times out. A value of zero
12575 disables the timeout.
12577 @item @code{log-compression} (default: @code{'bzip2})
12578 The type of compression used for build logs---one of @code{gzip},
12579 @code{bzip2}, or @code{none}.
12581 @item @code{extra-options} (default: @code{'()})
12582 List of extra command-line options for @command{guix-daemon}.
12584 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12585 File where @command{guix-daemon}'s standard output and standard error
12588 @item @code{http-proxy} (default: @code{#f})
12589 The HTTP proxy used for downloading fixed-output derivations and
12592 @item @code{tmpdir} (default: @code{#f})
12593 A directory path where the @command{guix-daemon} will perform builds.
12598 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12599 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12600 udev rules can be provided as a list of files through the @var{rules}
12601 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12602 @code{(gnu services base)} simplify the creation of such rule files.
12605 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12606 Return a udev-rule file named @var{file-name} containing the rules
12607 defined by the @var{contents} literal.
12609 In the following example, a rule for a USB device is defined to be
12610 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12611 upon detecting a USB device with a given product identifier.
12614 (define %example-udev-rule
12616 "90-usb-thing.rules"
12617 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12618 "ATTR@{product@}==\"Example\", "
12619 "RUN+=\"/path/to/script\"")))
12622 The @command{herd rules udev} command, as root, returns the name of the
12623 directory containing all the active udev rules.
12626 Here we show how the default @var{udev-service} can be extended with it.
12632 (modify-services %desktop-services
12633 (udev-service-type config =>
12634 (udev-configuration (inherit config)
12635 (rules (append (udev-configuration-rules config)
12636 (list %example-udev-rule))))))))
12639 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12640 Return a udev file named @var{file-name} containing the rules defined
12641 within @var{file}, a file-like object.
12643 The following example showcases how we can use an existing rule file.
12646 (use-modules (guix download) ;for url-fetch
12647 (guix packages) ;for origin
12650 (define %android-udev-rules
12652 "51-android-udev.rules"
12653 (let ((version "20170910"))
12656 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12657 "android-udev-rules/" version "/51-android.rules"))
12659 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12663 Additionally, Guix package definitions can be included in @var{rules} in
12664 order to extend the udev rules with the definitions found under their
12665 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12666 @var{file->udev-rule} example, we could have used the
12667 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12668 packages android)} module.
12670 The following example shows how to use the @var{android-udev-rules}
12671 package so that the Android tool @command{adb} can detect devices
12672 without root privileges. It also details how to create the
12673 @code{adbusers} group, which is required for the proper functioning of
12674 the rules defined within the @var{android-udev-rules} package. To
12675 create such a group, we must define it both as part of the
12676 @var{supplementary-groups} of our @var{user-account} declaration, as
12677 well as in the @var{groups} field of the @var{operating-system} record.
12680 (use-modules (gnu packages android) ;for android-udev-rules
12681 (gnu system shadow) ;for user-group
12686 (users (cons (user-acount
12688 (supplementary-groups
12689 '("adbusers" ;for adb
12690 "wheel" "netdev" "audio" "video")))))
12692 (groups (cons (user-group (system? #t) (name "adbusers"))
12698 (modify-services %desktop-services
12701 (udev-configuration (inherit config)
12702 (rules (cons android-udev-rules
12703 (udev-configuration-rules config))))))))
12706 @defvr {Scheme Variable} urandom-seed-service-type
12707 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12708 when rebooting. It also tries to seed @file{/dev/urandom} from
12709 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12713 @defvr {Scheme Variable} %random-seed-file
12714 This is the name of the file where some random bytes are saved by
12715 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12716 It defaults to @file{/var/lib/random-seed}.
12721 @defvr {Scheme Variable} gpm-service-type
12722 This is the type of the service that runs GPM, the @dfn{general-purpose
12723 mouse daemon}, which provides mouse support to the Linux console. GPM
12724 allows users to use the mouse in the console, notably to select, copy,
12727 The value for services of this type must be a @code{gpm-configuration}
12728 (see below). This service is not part of @code{%base-services}.
12731 @deftp {Data Type} gpm-configuration
12732 Data type representing the configuration of GPM.
12735 @item @code{options} (default: @code{%default-gpm-options})
12736 Command-line options passed to @command{gpm}. The default set of
12737 options instruct @command{gpm} to listen to mouse events on
12738 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12741 @item @code{gpm} (default: @code{gpm})
12742 The GPM package to use.
12747 @anchor{guix-publish-service-type}
12748 @deffn {Scheme Variable} guix-publish-service-type
12749 This is the service type for @command{guix publish} (@pxref{Invoking
12750 guix publish}). Its value must be a @code{guix-publish-configuration}
12751 object, as described below.
12753 This assumes that @file{/etc/guix} already contains a signing key pair as
12754 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12755 archive}). If that is not the case, the service will fail to start.
12758 @deftp {Data Type} guix-publish-configuration
12759 Data type representing the configuration of the @code{guix publish}
12763 @item @code{guix} (default: @code{guix})
12764 The Guix package to use.
12766 @item @code{port} (default: @code{80})
12767 The TCP port to listen for connections.
12769 @item @code{host} (default: @code{"localhost"})
12770 The host (and thus, network interface) to listen to. Use
12771 @code{"0.0.0.0"} to listen on all the network interfaces.
12773 @item @code{compression} (default: @code{'(("gzip" 3))})
12774 This is a list of compression method/level tuple used when compressing
12775 substitutes. For example, to compress all substitutes with @emph{both} lzip
12776 at level 7 and gzip at level 9, write:
12779 '(("lzip" 7) ("gzip" 9))
12782 Level 9 achieves the best compression ratio at the expense of increased CPU
12783 usage, whereas level 1 achieves fast compression.
12785 An empty list disables compression altogether.
12787 @item @code{nar-path} (default: @code{"nar"})
12788 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12789 publish, @code{--nar-path}}, for details.
12791 @item @code{cache} (default: @code{#f})
12792 When it is @code{#f}, disable caching and instead generate archives on
12793 demand. Otherwise, this should be the name of a directory---e.g.,
12794 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12795 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12796 @option{--cache}}, for more information on the tradeoffs involved.
12798 @item @code{workers} (default: @code{#f})
12799 When it is an integer, this is the number of worker threads used for
12800 caching; when @code{#f}, the number of processors is used.
12801 @xref{Invoking guix publish, @option{--workers}}, for more information.
12803 @item @code{ttl} (default: @code{#f})
12804 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12805 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12806 for more information.
12810 @anchor{rngd-service}
12811 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12812 [#:device "/dev/hwrng"]
12813 Return a service that runs the @command{rngd} program from @var{rng-tools}
12814 to add @var{device} to the kernel's entropy pool. The service will fail if
12815 @var{device} does not exist.
12818 @anchor{pam-limits-service}
12819 @cindex session limits
12824 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12826 Return a service that installs a configuration file for the
12827 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12828 @code{pam_limits} module}. The procedure optionally takes a list of
12829 @code{pam-limits-entry} values, which can be used to specify
12830 @code{ulimit} limits and nice priority limits to user sessions.
12832 The following limits definition sets two hard and soft limits for all
12833 login sessions of users in the @code{realtime} group:
12836 (pam-limits-service
12838 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12839 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12842 The first entry increases the maximum realtime priority for
12843 non-privileged processes; the second entry lifts any restriction of the
12844 maximum address space that can be locked in memory. These settings are
12845 commonly used for real-time audio systems.
12848 @node Scheduled Job Execution
12849 @subsection Scheduled Job Execution
12853 @cindex scheduling jobs
12854 The @code{(gnu services mcron)} module provides an interface to
12855 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12856 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12857 Unix @command{cron} daemon; the main difference is that it is
12858 implemented in Guile Scheme, which provides a lot of flexibility when
12859 specifying the scheduling of jobs and their actions.
12861 The example below defines an operating system that runs the
12862 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12863 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12864 well as the @command{mkid} command on behalf of an unprivileged user
12865 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12866 gexps to introduce job definitions that are passed to mcron
12867 (@pxref{G-Expressions}).
12870 (use-modules (guix) (gnu) (gnu services mcron))
12871 (use-package-modules base idutils)
12873 (define updatedb-job
12874 ;; Run 'updatedb' at 3AM every day. Here we write the
12875 ;; job's action as a Scheme procedure.
12876 #~(job '(next-hour '(3))
12878 (execl (string-append #$findutils "/bin/updatedb")
12880 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12882 (define garbage-collector-job
12883 ;; Collect garbage 5 minutes after midnight every day.
12884 ;; The job's action is a shell command.
12885 #~(job "5 0 * * *" ;Vixie cron syntax
12888 (define idutils-job
12889 ;; Update the index database as user "charlie" at 12:15PM
12890 ;; and 19:15PM. This runs from the user's home directory.
12891 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12892 (string-append #$idutils "/bin/mkid src")
12897 (services (cons (service mcron-service-type
12898 (mcron-configuration
12899 (jobs (list garbage-collector-job
12905 For more complex jobs defined in Scheme where you need control over the top
12906 level, for instance to introduce a @code{use-modules} form, you can move your
12907 code to a separate program using the @code{program-file} procedure of the
12908 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
12912 (define %battery-alert-job
12913 ;; Beep when the battery percentage falls below %MIN-LEVEL.
12915 '(next-minute (range 0 60 1))
12917 "battery-alert.scm"
12918 (with-imported-modules (source-module-closure
12919 '((guix build utils)))
12921 (define %min-level 20)
12922 (use-modules (guix build utils)
12925 (ice-9 textual-ports)
12927 (setenv "LC_ALL" "C") ;ensure English output
12928 (and-let* ((input-pipe (open-pipe*
12930 #$(file-append acpi "/bin/acpi")))
12931 (output (get-string-all input-pipe))
12932 (m (string-match "Discharging, ([0-9]+)%" output))
12933 (level (string->number (match:substring m 1)))
12934 ((< level %min-level)))
12935 (format #t "warning: Battery level is low (~a%)~%" level)
12936 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
12939 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12940 for more information on mcron job specifications. Below is the
12941 reference of the mcron service.
12943 On a running system, you can use the @code{schedule} action of the service to
12944 visualize the mcron jobs that will be executed next:
12947 # herd schedule mcron
12951 The example above lists the next five tasks that will be executed, but you can
12952 also specify the number of tasks to display:
12955 # herd schedule mcron 10
12958 @defvr {Scheme Variable} mcron-service-type
12959 This is the type of the @code{mcron} service, whose value is an
12960 @code{mcron-configuration} object.
12962 This service type can be the target of a service extension that provides
12963 it additional job specifications (@pxref{Service Composition}). In
12964 other words, it is possible to define services that provide additional
12968 @deftp {Data Type} mcron-configuration
12969 Data type representing the configuration of mcron.
12972 @item @code{mcron} (default: @var{mcron})
12973 The mcron package to use.
12976 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12977 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12978 specifications,, mcron, GNU@tie{}mcron}).
12984 @subsection Log Rotation
12987 @cindex log rotation
12989 Log files such as those found in @file{/var/log} tend to grow endlessly,
12990 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12991 their contents in separate files, possibly compressed. The @code{(gnu
12992 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12993 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12995 The example below defines an operating system that provides log rotation
12996 with the default settings, for commonly encountered log files.
12999 (use-modules (guix) (gnu))
13000 (use-service-modules admin mcron)
13001 (use-package-modules base idutils)
13005 (services (cons (service rottlog-service-type)
13009 @defvr {Scheme Variable} rottlog-service-type
13010 This is the type of the Rottlog service, whose value is a
13011 @code{rottlog-configuration} object.
13013 Other services can extend this one with new @code{log-rotation} objects
13014 (see below), thereby augmenting the set of files to be rotated.
13016 This service type can define mcron jobs (@pxref{Scheduled Job
13017 Execution}) to run the rottlog service.
13020 @deftp {Data Type} rottlog-configuration
13021 Data type representing the configuration of rottlog.
13024 @item @code{rottlog} (default: @code{rottlog})
13025 The Rottlog package to use.
13027 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13028 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13029 rottlog, GNU Rot[t]log Manual}).
13031 @item @code{rotations} (default: @code{%default-rotations})
13032 A list of @code{log-rotation} objects as defined below.
13035 This is a list of gexps where each gexp corresponds to an mcron job
13036 specification (@pxref{Scheduled Job Execution}).
13040 @deftp {Data Type} log-rotation
13041 Data type representing the rotation of a group of log files.
13043 Taking an example from the Rottlog manual (@pxref{Period Related File
13044 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13050 (files '("/var/log/apache/*"))
13051 (options '("storedir apache-archives"
13057 The list of fields is as follows:
13060 @item @code{frequency} (default: @code{'weekly})
13061 The log rotation frequency, a symbol.
13064 The list of files or file glob patterns to rotate.
13066 @item @code{options} (default: @code{'()})
13067 The list of rottlog options for this rotation (@pxref{Configuration
13068 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13070 @item @code{post-rotate} (default: @code{#f})
13071 Either @code{#f} or a gexp to execute once the rotation has completed.
13075 @defvr {Scheme Variable} %default-rotations
13076 Specifies weekly rotation of @var{%rotated-files} and of
13077 @file{/var/log/guix-daemon.log}.
13080 @defvr {Scheme Variable} %rotated-files
13081 The list of syslog-controlled files to be rotated. By default it is:
13082 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13083 "/var/log/maillog")}.
13086 @node Networking Services
13087 @subsection Networking Services
13089 The @code{(gnu services networking)} module provides services to configure
13090 the network interface.
13092 @cindex DHCP, networking service
13093 @defvr {Scheme Variable} dhcp-client-service-type
13094 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13095 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13096 is the DHCP client package to use, @code{isc-dhcp} by default.
13099 @deffn {Scheme Procedure} dhcpd-service-type
13100 This type defines a service that runs a DHCP daemon. To create a
13101 service of this type, you must supply a @code{<dhcpd-configuration>}.
13105 (service dhcpd-service-type
13106 (dhcpd-configuration
13107 (config-file (local-file "my-dhcpd.conf"))
13108 (interfaces '("enp0s25"))))
13112 @deftp {Data Type} dhcpd-configuration
13114 @item @code{package} (default: @code{isc-dhcp})
13115 The package that provides the DHCP daemon. This package is expected to
13116 provide the daemon at @file{sbin/dhcpd} relative to its output
13117 directory. The default package is the
13118 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13119 @item @code{config-file} (default: @code{#f})
13120 The configuration file to use. This is required. It will be passed to
13121 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13122 object (@pxref{G-Expressions, file-like objects}). See @code{man
13123 dhcpd.conf} for details on the configuration file syntax.
13124 @item @code{version} (default: @code{"4"})
13125 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13126 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13127 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13129 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13130 The run directory to use. At service activation time, this directory
13131 will be created if it does not exist.
13132 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13133 The PID file to use. This corresponds to the @code{-pf} option of
13134 @code{dhcpd}. See @code{man dhcpd} for details.
13135 @item @code{interfaces} (default: @code{'()})
13136 The names of the network interfaces on which dhcpd should listen for
13137 broadcasts. If this list is not empty, then its elements (which must be
13138 strings) will be appended to the @code{dhcpd} invocation when starting
13139 the daemon. It may not be necessary to explicitly specify any
13140 interfaces here; see @code{man dhcpd} for details.
13144 @defvr {Scheme Variable} static-networking-service-type
13145 This is the type for statically-configured network interfaces.
13146 @c TODO Document <static-networking> data structures.
13149 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13150 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13151 [#:requirement @code{'(udev)}]
13152 Return a service that starts @var{interface} with address @var{ip}. If
13153 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13154 it must be a string specifying the default network gateway. @var{requirement}
13155 can be used to declare a dependency on another service before configuring the
13158 This procedure can be called several times, one for each network
13159 interface of interest. Behind the scenes what it does is extend
13160 @code{static-networking-service-type} with additional network interfaces
13166 (static-networking-service "eno1" "192.168.1.82"
13167 #:gateway "192.168.1.2"
13168 #:name-servers '("192.168.1.2"))
13175 @cindex network management
13176 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13177 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13178 management daemon that aims to simplify wired and wireless networking.
13180 This service adds the @var{wicd} package to the global profile, providing
13181 several commands to interact with the daemon and configure networking:
13182 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13183 and @command{wicd-curses} user interfaces.
13186 @cindex ModemManager
13188 @defvr {Scheme Variable} modem-manager-service-type
13189 This is the service type for the
13190 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13191 service. The value for this service type is a
13192 @code{modem-manager-configuration} record.
13194 This service is part of @code{%desktop-services} (@pxref{Desktop
13198 @deftp {Data Type} modem-manager-configuration
13199 Data type representing the configuration of ModemManager.
13202 @item @code{modem-manager} (default: @code{modem-manager})
13203 The ModemManager package to use.
13208 @cindex USB_ModeSwitch
13209 @cindex Modeswitching
13211 @defvr {Scheme Variable} usb-modeswitch-service-type
13212 This is the service type for the
13213 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13214 value for this service type is a @code{usb-modeswitch-configuration} record.
13216 When plugged in, some USB modems (and other USB devices) initially present
13217 themselves as a read-only storage medium and not as a modem. They need to be
13218 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13219 installs udev rules to automatically modeswitch these devices when they are
13222 This service is part of @code{%desktop-services} (@pxref{Desktop
13226 @deftp {Data Type} usb-modeswitch-configuration
13227 Data type representing the configuration of USB_ModeSwitch.
13230 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13231 The USB_ModeSwitch package providing the binaries for modeswitching.
13233 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13234 The package providing the device data and udev rules file used by
13237 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13238 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13239 config file shipped with USB_ModeSwitch is used which disables logging to
13240 @file{/var/log} among other default settings. If set to @code{#f}, no config
13246 @cindex NetworkManager
13248 @defvr {Scheme Variable} network-manager-service-type
13249 This is the service type for the
13250 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13251 service. The value for this service type is a
13252 @code{network-manager-configuration} record.
13254 This service is part of @code{%desktop-services} (@pxref{Desktop
13258 @deftp {Data Type} network-manager-configuration
13259 Data type representing the configuration of NetworkManager.
13262 @item @code{network-manager} (default: @code{network-manager})
13263 The NetworkManager package to use.
13265 @item @code{dns} (default: @code{"default"})
13266 Processing mode for DNS, which affects how NetworkManager uses the
13267 @code{resolv.conf} configuration file.
13271 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13272 provided by currently active connections.
13275 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13276 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13277 then update @code{resolv.conf} to point to the local nameserver.
13279 With this setting, you can share your network connection. For example when
13280 you want to share your network connection to another laptop @i{via} an
13281 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13282 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13283 and reestablish the connection (or reboot).
13285 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13286 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13287 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13288 browser on your host system, or connect to the VM @i{via} SSH
13289 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13290 host-to-guest connection, run this command once:
13293 nmcli connection add type tun \
13294 connection.interface-name tap0 \
13295 tun.mode tap tun.owner $(id -u) \
13296 ipv4.method shared \
13297 ipv4.addresses 172.28.112.1/24
13300 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13301 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13302 @command{qemu-system-...}.
13305 NetworkManager will not modify @code{resolv.conf}.
13308 @item @code{vpn-plugins} (default: @code{'()})
13309 This is the list of available plugins for virtual private networks
13310 (VPNs). An example of this is the @code{network-manager-openvpn}
13311 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13317 @deffn {Scheme Variable} connman-service-type
13318 This is the service type to run @url{https://01.org/connman,Connman},
13319 a network connection manager.
13321 Its value must be an
13322 @code{connman-configuration} record as in this example:
13325 (service connman-service-type
13326 (connman-configuration
13327 (disable-vpn? #t)))
13330 See below for details about @code{connman-configuration}.
13333 @deftp {Data Type} connman-configuration
13334 Data Type representing the configuration of connman.
13337 @item @code{connman} (default: @var{connman})
13338 The connman package to use.
13340 @item @code{disable-vpn?} (default: @code{#f})
13341 When true, disable connman's vpn plugin.
13345 @cindex WPA Supplicant
13346 @defvr {Scheme Variable} wpa-supplicant-service-type
13347 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13348 supplicant}, an authentication daemon required to authenticate against
13349 encrypted WiFi or ethernet networks.
13352 @deftp {Data Type} wpa-supplicant-configuration
13353 Data type representing the configuration of WPA Supplicant.
13355 It takes the following parameters:
13358 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13359 The WPA Supplicant package to use.
13361 @item @code{dbus?} (default: @code{#t})
13362 Whether to listen for requests on D-Bus.
13364 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13365 Where to store the PID file.
13367 @item @code{interface} (default: @code{#f})
13368 If this is set, it must specify the name of a network interface that
13369 WPA supplicant will control.
13371 @item @code{config-file} (default: @code{#f})
13372 Optional configuration file to use.
13374 @item @code{extra-options} (default: @code{'()})
13375 List of additional command-line arguments to pass to the daemon.
13380 @defvr {Scheme Variable} iptables-service-type
13381 This is the service type to set up an iptables configuration. iptables is a
13382 packet filtering framework supported by the Linux kernel. This service
13383 supports configuring iptables for both IPv4 and IPv6. A simple example
13384 configuration rejecting all incoming connections except those to the ssh port
13388 (service iptables-service-type
13389 (iptables-configuration
13390 (ipv4-rules (plain-file "iptables.rules" "*filter
13394 -A INPUT -p tcp --dport 22 -j ACCEPT
13395 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13398 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13402 -A INPUT -p tcp --dport 22 -j ACCEPT
13403 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13409 @deftp {Data Type} iptables-configuration
13410 The data type representing the configuration of iptables.
13413 @item @code{iptables} (default: @code{iptables})
13414 The iptables package that provides @code{iptables-restore} and
13415 @code{ip6tables-restore}.
13416 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13417 The iptables rules to use. It will be passed to @code{iptables-restore}.
13418 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13420 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13421 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13422 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13428 @defvr {Scheme Variable} nftables-service-type
13429 This is the service type to set up a nftables configuration. nftables is a
13430 netfilter project that aims to replace the existing iptables, ip6tables,
13431 arptables and ebtables framework. It provides a new packet filtering
13432 framework, a new user-space utility @command{nft}, and a compatibility layer
13433 for iptables. This service comes with a default ruleset
13434 @code{%default-nftables-ruleset} that rejecting all incomming connections
13435 except those to the ssh port 22. To use it, simply write:
13438 (service nftables-service-type)
13442 @deftp {Data Type} nftables-configuration
13443 The data type representing the configuration of nftables.
13446 @item @code{package} (default: @code{nftables})
13447 The nftables package that provides @command{nft}.
13448 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13449 The nftables ruleset to use. This may be any ``file-like'' object
13450 (@pxref{G-Expressions, file-like objects}).
13454 @cindex NTP (Network Time Protocol), service
13455 @cindex ntpd, service for the Network Time Protocol daemon
13456 @cindex real time clock
13457 @defvr {Scheme Variable} ntp-service-type
13458 This is the type of the service running the @uref{http://www.ntp.org,
13459 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13460 system clock synchronized with that of the specified NTP servers.
13462 The value of this service is an @code{ntpd-configuration} object, as described
13466 @deftp {Data Type} ntp-configuration
13467 This is the data type for the NTP service configuration.
13470 @item @code{servers} (default: @code{%ntp-servers})
13471 This is the list of servers (@code{<ntp-server>} records) with which
13472 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13475 @item @code{allow-large-adjustment?} (default: @code{#t})
13476 This determines whether @command{ntpd} is allowed to make an initial
13477 adjustment of more than 1,000 seconds.
13479 @item @code{ntp} (default: @code{ntp})
13480 The NTP package to use.
13484 @defvr {Scheme Variable} %ntp-servers
13485 List of host names used as the default NTP servers. These are servers of the
13486 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13489 @deftp {Data Type} ntp-server
13490 The data type representing the configuration of a NTP server.
13493 @item @code{type} (default: @code{'server})
13494 The type of the NTP server, given as a symbol. One of @code{'pool},
13495 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13497 @item @code{address}
13498 The address of the server, as a string.
13500 @item @code{options}
13501 NTPD options to use with that specific server, given as a list of option names
13502 and/or of option names and values tuples. The following example define a server
13503 to use with the options @option{iburst} and @option{prefer}, as well as
13504 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13509 (address "some.ntp.server.org")
13510 (options `(iburst (version 3) (maxpoll 16) prefer))))
13516 @deffn {Scheme Procedure} openntpd-service-type
13517 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13518 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13519 clock synchronized with that of the given servers.
13523 openntpd-service-type
13524 (openntpd-configuration
13525 (listen-on '("127.0.0.1" "::1"))
13526 (sensor '("udcf0 correction 70000"))
13527 (constraint-from '("www.gnu.org"))
13528 (constraints-from '("https://www.google.com/"))
13529 (allow-large-adjustment? #t)))
13534 @defvr {Scheme Variable} %openntpd-servers
13535 This variable is a list of the server addresses defined in
13536 @var{%ntp-servers}.
13539 @deftp {Data Type} openntpd-configuration
13541 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13542 The openntpd executable to use.
13543 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13544 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13545 @item @code{query-from} (default: @code{'()})
13546 A list of local IP address the ntpd daemon should use for outgoing queries.
13547 @item @code{sensor} (default: @code{'()})
13548 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13549 will listen to each sensor that actually exists and ignore non-existent ones.
13550 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13552 @item @code{server} (default: @code{'()})
13553 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13554 @item @code{servers} (default: @var{%openntp-servers})
13555 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13556 @item @code{constraint-from} (default: @code{'()})
13557 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13558 This time information is not used for precision but acts as an authenticated
13559 constraint, thereby reducing the impact of unauthenticated NTP
13560 man-in-the-middle attacks.
13561 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13563 @item @code{constraints-from} (default: @code{'()})
13564 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13565 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13566 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13567 @item @code{allow-large-adjustment?} (default: @code{#f})
13568 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13574 @deffn {Scheme variable} inetd-service-type
13575 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13576 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13577 connections on internet sockets, and lazily starts the specified server
13578 program when a connection is made on one of these sockets.
13580 The value of this service is an @code{inetd-configuration} object. The
13581 following example configures the @command{inetd} daemon to provide the
13582 built-in @command{echo} service, as well as an smtp service which
13583 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13584 gateway @code{hostname}:
13589 (inetd-configuration
13593 (socket-type 'stream)
13600 (socket-type 'stream)
13604 (program (file-append openssh "/bin/ssh"))
13606 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13607 "-W" "smtp-server:25" "user@@hostname")))))))
13610 See below for more details about @code{inetd-configuration}.
13613 @deftp {Data Type} inetd-configuration
13614 Data type representing the configuration of @command{inetd}.
13617 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13618 The @command{inetd} executable to use.
13620 @item @code{entries} (default: @code{'()})
13621 A list of @command{inetd} service entries. Each entry should be created
13622 by the @code{inetd-entry} constructor.
13626 @deftp {Data Type} inetd-entry
13627 Data type representing an entry in the @command{inetd} configuration.
13628 Each entry corresponds to a socket where @command{inetd} will listen for
13632 @item @code{node} (default: @code{#f})
13633 Optional string, a comma-separated list of local addresses
13634 @command{inetd} should use when listening for this service.
13635 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13636 description of all options.
13638 A string, the name must correspond to an entry in @code{/etc/services}.
13639 @item @code{socket-type}
13640 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13642 @item @code{protocol}
13643 A string, must correspond to an entry in @code{/etc/protocols}.
13644 @item @code{wait?} (default: @code{#t})
13645 Whether @command{inetd} should wait for the server to exit before
13646 listening to new service requests.
13648 A string containing the user (and, optionally, group) name of the user
13649 as whom the server should run. The group name can be specified in a
13650 suffix, separated by a colon or period, i.e.@: @code{"user"},
13651 @code{"user:group"} or @code{"user.group"}.
13652 @item @code{program} (default: @code{"internal"})
13653 The server program which will serve the requests, or @code{"internal"}
13654 if @command{inetd} should use a built-in service.
13655 @item @code{arguments} (default: @code{'()})
13656 A list strings or file-like objects, which are the server program's
13657 arguments, starting with the zeroth argument, i.e.@: the name of the
13658 program itself. For @command{inetd}'s internal services, this entry
13659 must be @code{'()} or @code{'("internal")}.
13662 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13663 detailed discussion of each configuration field.
13667 @defvr {Scheme Variable} tor-service-type
13668 This is the type for a service that runs the @uref{https://torproject.org,
13669 Tor} anonymous networking daemon. The service is configured using a
13670 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13671 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13675 @deftp {Data Type} tor-configuration
13677 @item @code{tor} (default: @code{tor})
13678 The package that provides the Tor daemon. This package is expected to provide
13679 the daemon at @file{bin/tor} relative to its output directory. The default
13680 package is the @uref{https://www.torproject.org, Tor Project's}
13683 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13684 The configuration file to use. It will be appended to a default configuration
13685 file, and the final configuration file will be passed to @code{tor} via its
13686 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13687 file-like objects}). See @code{man tor} for details on the configuration file
13690 @item @code{hidden-services} (default: @code{'()})
13691 The list of @code{<hidden-service>} records to use. For any hidden service
13692 you include in this list, appropriate configuration to enable the hidden
13693 service will be automatically added to the default configuration file. You
13694 may conveniently create @code{<hidden-service>} records using the
13695 @code{tor-hidden-service} procedure described below.
13697 @item @code{socks-socket-type} (default: @code{'tcp})
13698 The default socket type that Tor should use for its SOCKS socket. This must
13699 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13700 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13701 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13702 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13705 If you want to customize the SOCKS socket in more detail, leave
13706 @code{socks-socket-type} at its default value of @code{'tcp} and use
13707 @code{config-file} to override the default by providing your own
13708 @code{SocksPort} option.
13712 @cindex hidden service
13713 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13714 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13715 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13718 '((22 "127.0.0.1:22")
13719 (80 "127.0.0.1:8080"))
13722 In this example, port 22 of the hidden service is mapped to local port 22, and
13723 port 80 is mapped to local port 8080.
13725 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13726 the @file{hostname} file contains the @code{.onion} host name for the hidden
13729 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13730 project's documentation} for more information.
13733 The @code{(gnu services rsync)} module provides the following services:
13735 You might want an rsync daemon if you have files that you want available
13736 so anyone (or just yourself) can download existing files or upload new
13739 @deffn {Scheme Variable} rsync-service-type
13740 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13741 The value for this service type is a
13742 @command{rsync-configuration} record as in this example:
13745 (service rsync-service-type)
13748 See below for details about @code{rsync-configuration}.
13751 @deftp {Data Type} rsync-configuration
13752 Data type representing the configuration for @code{rsync-service}.
13755 @item @code{package} (default: @var{rsync})
13756 @code{rsync} package to use.
13758 @item @code{port-number} (default: @code{873})
13759 TCP port on which @command{rsync} listens for incoming connections. If port
13760 is less than @code{1024} @command{rsync} needs to be started as the
13761 @code{root} user and group.
13763 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13764 Name of the file where @command{rsync} writes its PID.
13766 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13767 Name of the file where @command{rsync} writes its lock file.
13769 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13770 Name of the file where @command{rsync} writes its log file.
13772 @item @code{use-chroot?} (default: @var{#t})
13773 Whether to use chroot for @command{rsync} shared directory.
13775 @item @code{share-path} (default: @file{/srv/rsync})
13776 Location of the @command{rsync} shared directory.
13778 @item @code{share-comment} (default: @code{"Rsync share"})
13779 Comment of the @command{rsync} shared directory.
13781 @item @code{read-only?} (default: @var{#f})
13782 Read-write permissions to shared directory.
13784 @item @code{timeout} (default: @code{300})
13785 I/O timeout in seconds.
13787 @item @code{user} (default: @var{"root"})
13788 Owner of the @code{rsync} process.
13790 @item @code{group} (default: @var{"root"})
13791 Group of the @code{rsync} process.
13793 @item @code{uid} (default: @var{"rsyncd"})
13794 User name or user ID that file transfers to and from that module should take
13795 place as when the daemon was run as @code{root}.
13797 @item @code{gid} (default: @var{"rsyncd"})
13798 Group name or group ID that will be used when accessing the module.
13803 Furthermore, @code{(gnu services ssh)} provides the following services.
13807 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13808 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13809 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13810 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13811 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13812 [#:public-key-authentication? #t] [#:initialize? #t]
13813 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13814 @var{host-key} must designate a file containing the host key, and readable
13817 When @var{daemonic?} is true, @command{lshd} will detach from the
13818 controlling terminal and log its output to syslogd, unless one sets
13819 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13820 depend on existence of syslogd service. When @var{pid-file?} is true,
13821 @command{lshd} writes its PID to the file called @var{pid-file}.
13823 When @var{initialize?} is true, automatically create the seed and host key
13824 upon service activation if they do not exist yet. This may take long and
13825 require interaction.
13827 When @var{initialize?} is false, it is up to the user to initialize the
13828 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13829 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13830 basics,,, lsh, LSH Manual}).
13832 When @var{interfaces} is empty, lshd listens for connections on all the
13833 network interfaces; otherwise, @var{interfaces} must be a list of host names
13836 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13837 passwords, and @var{root-login?} specifies whether to accept log-ins as
13840 The other options should be self-descriptive.
13845 @deffn {Scheme Variable} openssh-service-type
13846 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13847 shell daemon, @command{sshd}. Its value must be an
13848 @code{openssh-configuration} record as in this example:
13851 (service openssh-service-type
13852 (openssh-configuration
13853 (x11-forwarding? #t)
13854 (permit-root-login 'without-password)
13856 `(("alice" ,(local-file "alice.pub"))
13857 ("bob" ,(local-file "bob.pub"))))))
13860 See below for details about @code{openssh-configuration}.
13862 This service can be extended with extra authorized keys, as in this
13866 (service-extension openssh-service-type
13867 (const `(("charlie"
13868 ,(local-file "charlie.pub")))))
13872 @deftp {Data Type} openssh-configuration
13873 This is the configuration record for OpenSSH's @command{sshd}.
13876 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13877 Name of the file where @command{sshd} writes its PID.
13879 @item @code{port-number} (default: @code{22})
13880 TCP port on which @command{sshd} listens for incoming connections.
13882 @item @code{permit-root-login} (default: @code{#f})
13883 This field determines whether and when to allow logins as root. If
13884 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13885 If it's the symbol @code{'without-password}, then root logins are
13886 permitted but not with password-based authentication.
13888 @item @code{allow-empty-passwords?} (default: @code{#f})
13889 When true, users with empty passwords may log in. When false, they may
13892 @item @code{password-authentication?} (default: @code{#t})
13893 When true, users may log in with their password. When false, they have
13894 other authentication methods.
13896 @item @code{public-key-authentication?} (default: @code{#t})
13897 When true, users may log in using public key authentication. When
13898 false, users have to use other authentication method.
13900 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13901 This is used only by protocol version 2.
13903 @item @code{x11-forwarding?} (default: @code{#f})
13904 When true, forwarding of X11 graphical client connections is
13905 enabled---in other words, @command{ssh} options @option{-X} and
13906 @option{-Y} will work.
13908 @item @code{allow-agent-forwarding?} (default: @code{#t})
13909 Whether to allow agent forwarding.
13911 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13912 Whether to allow TCP forwarding.
13914 @item @code{gateway-ports?} (default: @code{#f})
13915 Whether to allow gateway ports.
13917 @item @code{challenge-response-authentication?} (default: @code{#f})
13918 Specifies whether challenge response authentication is allowed (e.g.@: via
13921 @item @code{use-pam?} (default: @code{#t})
13922 Enables the Pluggable Authentication Module interface. If set to
13923 @code{#t}, this will enable PAM authentication using
13924 @code{challenge-response-authentication?} and
13925 @code{password-authentication?}, in addition to PAM account and session
13926 module processing for all authentication types.
13928 Because PAM challenge response authentication usually serves an
13929 equivalent role to password authentication, you should disable either
13930 @code{challenge-response-authentication?} or
13931 @code{password-authentication?}.
13933 @item @code{print-last-log?} (default: @code{#t})
13934 Specifies whether @command{sshd} should print the date and time of the
13935 last user login when a user logs in interactively.
13937 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13938 Configures external subsystems (e.g.@: file transfer daemon).
13940 This is a list of two-element lists, each of which containing the
13941 subsystem name and a command (with optional arguments) to execute upon
13944 The command @command{internal-sftp} implements an in-process SFTP
13945 server. Alternately, one can specify the @command{sftp-server} command:
13947 (service openssh-service-type
13948 (openssh-configuration
13950 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13953 @item @code{accepted-environment} (default: @code{'()})
13954 List of strings describing which environment variables may be exported.
13956 Each string gets on its own line. See the @code{AcceptEnv} option in
13957 @code{man sshd_config}.
13959 This example allows ssh-clients to export the @code{COLORTERM} variable.
13960 It is set by terminal emulators, which support colors. You can use it in
13961 your shell's ressource file to enable colors for the prompt and commands
13962 if this variable is set.
13965 (service openssh-service-type
13966 (openssh-configuration
13967 (accepted-environment '("COLORTERM"))))
13970 @item @code{authorized-keys} (default: @code{'()})
13971 @cindex authorized keys, SSH
13972 @cindex SSH authorized keys
13973 This is the list of authorized keys. Each element of the list is a user
13974 name followed by one or more file-like objects that represent SSH public
13978 (openssh-configuration
13980 `(("rekado" ,(local-file "rekado.pub"))
13981 ("chris" ,(local-file "chris.pub"))
13982 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13986 registers the specified public keys for user accounts @code{rekado},
13987 @code{chris}, and @code{root}.
13989 Additional authorized keys can be specified @i{via}
13990 @code{service-extension}.
13992 Note that this does @emph{not} interfere with the use of
13993 @file{~/.ssh/authorized_keys}.
13995 @item @code{log-level} (default: @code{'info})
13996 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13997 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13998 page for @file{sshd_config} for the full list of level names.
14000 @item @code{extra-content} (default: @code{""})
14001 This field can be used to append arbitrary text to the configuration file. It
14002 is especially useful for elaborate configurations that cannot be expressed
14003 otherwise. This configuration, for example, would generally disable root
14004 logins, but permit them from one specific IP address:
14007 (openssh-configuration
14009 Match Address 192.168.0.1
14010 PermitRootLogin yes"))
14016 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14017 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14018 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14021 For example, to specify a Dropbear service listening on port 1234, add
14022 this call to the operating system's @code{services} field:
14025 (dropbear-service (dropbear-configuration
14026 (port-number 1234)))
14030 @deftp {Data Type} dropbear-configuration
14031 This data type represents the configuration of a Dropbear SSH daemon.
14034 @item @code{dropbear} (default: @var{dropbear})
14035 The Dropbear package to use.
14037 @item @code{port-number} (default: 22)
14038 The TCP port where the daemon waits for incoming connections.
14040 @item @code{syslog-output?} (default: @code{#t})
14041 Whether to enable syslog output.
14043 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
14044 File name of the daemon's PID file.
14046 @item @code{root-login?} (default: @code{#f})
14047 Whether to allow @code{root} logins.
14049 @item @code{allow-empty-passwords?} (default: @code{#f})
14050 Whether to allow empty passwords.
14052 @item @code{password-authentication?} (default: @code{#t})
14053 Whether to enable password-based authentication.
14057 @defvr {Scheme Variable} %facebook-host-aliases
14058 This variable contains a string for use in @file{/etc/hosts}
14059 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
14060 line contains a entry that maps a known server name of the Facebook
14061 on-line service---e.g., @code{www.facebook.com}---to the local
14062 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
14064 This variable is typically used in the @code{hosts-file} field of an
14065 @code{operating-system} declaration (@pxref{operating-system Reference,
14066 @file{/etc/hosts}}):
14069 (use-modules (gnu) (guix))
14072 (host-name "mymachine")
14075 ;; Create a /etc/hosts file with aliases for "localhost"
14076 ;; and "mymachine", as well as for Facebook servers.
14077 (plain-file "hosts"
14078 (string-append (local-host-aliases host-name)
14079 %facebook-host-aliases))))
14082 This mechanism can prevent programs running locally, such as Web
14083 browsers, from accessing Facebook.
14086 The @code{(gnu services avahi)} provides the following definition.
14088 @defvr {Scheme Variable} avahi-service-type
14089 This is the service that runs @command{avahi-daemon}, a system-wide
14090 mDNS/DNS-SD responder that allows for service discovery and
14091 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14092 Its value must be a @code{zero-configuration} record---see below.
14094 This service extends the name service cache daemon (nscd) so that it can
14095 resolve @code{.local} host names using
14096 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14097 Service Switch}, for information on host name resolution.
14099 Additionally, add the @var{avahi} package to the system profile so that
14100 commands such as @command{avahi-browse} are directly usable.
14103 @deftp {Data Type} avahi-configuration
14104 Data type representation the configuration for Avahi.
14108 @item @code{host-name} (default: @code{#f})
14109 If different from @code{#f}, use that as the host name to
14110 publish for this machine; otherwise, use the machine's actual host name.
14112 @item @code{publish?} (default: @code{#t})
14113 When true, allow host names and services to be published (broadcast) over the
14116 @item @code{publish-workstation?} (default: @code{#t})
14117 When true, @command{avahi-daemon} publishes the machine's host name and IP
14118 address via mDNS on the local network. To view the host names published on
14119 your local network, you can run:
14122 avahi-browse _workstation._tcp
14125 @item @code{wide-area?} (default: @code{#f})
14126 When true, DNS-SD over unicast DNS is enabled.
14128 @item @code{ipv4?} (default: @code{#t})
14129 @itemx @code{ipv6?} (default: @code{#t})
14130 These fields determine whether to use IPv4/IPv6 sockets.
14132 @item @code{domains-to-browse} (default: @code{'()})
14133 This is a list of domains to browse.
14137 @deffn {Scheme Variable} openvswitch-service-type
14138 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14139 service, whose value should be an @code{openvswitch-configuration}
14143 @deftp {Data Type} openvswitch-configuration
14144 Data type representing the configuration of Open vSwitch, a multilayer
14145 virtual switch which is designed to enable massive network automation
14146 through programmatic extension.
14149 @item @code{package} (default: @var{openvswitch})
14150 Package object of the Open vSwitch.
14155 @defvr {Scheme Variable} pagekite-service-type
14156 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14157 a tunneling solution for making localhost servers publicly visible, even from
14158 behind restrictive firewalls or NAT without forwarded ports. The value for
14159 this service type is a @code{pagekite-configuration} record.
14161 Here's an example exposing the local HTTP and SSH daemons:
14164 (service pagekite-service-type
14165 (pagekite-configuration
14166 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14167 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14168 (extra-file "/etc/pagekite.rc")))
14172 @deftp {Data Type} pagekite-configuration
14173 Data type representing the configuration of PageKite.
14176 @item @code{package} (default: @var{pagekite})
14177 Package object of PageKite.
14179 @item @code{kitename} (default: @code{#f})
14180 PageKite name for authenticating to the frontend server.
14182 @item @code{kitesecret} (default: @code{#f})
14183 Shared secret for authenticating to the frontend server. You should probably
14184 put this inside @code{extra-file} instead.
14186 @item @code{frontend} (default: @code{#f})
14187 Connect to the named PageKite frontend server instead of the
14188 @uref{https://pagekite.net,,pagekite.net} service.
14190 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14191 List of service kites to use. Exposes HTTP on port 80 by default. The format
14192 is @code{proto:kitename:host:port:secret}.
14194 @item @code{extra-file} (default: @code{#f})
14195 Extra configuration file to read, which you are expected to create manually.
14196 Use this to add additional options and manage shared secrets out-of-band.
14202 @subsection X Window
14205 @cindex X Window System
14206 @cindex login manager
14207 Support for the X Window graphical display system---specifically
14208 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14209 there is no @code{xorg-service} procedure. Instead, the X server is
14210 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14213 @cindex GNOME, login manager
14214 GDM of course allows users to log in into window managers and desktop
14215 environments other than GNOME; for those using GNOME, GDM is required for
14216 features such as automatic screen locking.
14218 @cindex window manager
14219 To use X11, you must install at least one @dfn{window manager}---for
14220 example the @code{windowmaker} or @code{openbox} packages---preferably
14221 by adding it to the @code{packages} field of your operating system
14222 definition (@pxref{operating-system Reference, system-wide packages}).
14224 @defvr {Scheme Variable} gdm-service-type
14225 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14226 Desktop Manager} (GDM), a program that manages graphical display servers and
14227 handles graphical user logins. Its value must be a @code{gdm-configuration}
14230 @cindex session types (X11)
14231 @cindex X11 session types
14232 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14233 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14234 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14235 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14236 set of packages automatically makes them available at the log-in screen.
14238 In addition, @file{~/.xsession} files are honored. When available,
14239 @file{~/.xsession} must be an executable that starts a window manager
14240 and/or other X clients.
14243 @deftp {Data Type} gdm-configuration
14245 @item @code{auto-login?} (default: @code{#f})
14246 @itemx @code{default-user} (default: @code{#f})
14247 When @code{auto-login?} is false, GDM presents a log-in screen.
14249 When @code{auto-login?} is true, GDM logs in directly as
14250 @code{default-user}.
14252 @item @code{debug?} (default: @code{#f})
14253 When true, GDM writes debug messages to its log.
14255 @item @code{gnome-shell-assets} (default: ...)
14256 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14258 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14259 Configuration of the Xorg graphical server.
14261 @item @code{xsession} (default: @code{(xinitrc)})
14262 Script to run before starting a X session.
14264 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14265 File name of the @code{dbus-daemon} executable.
14267 @item @code{gdm} (default: @code{gdm})
14268 The GDM package to use.
14272 @defvr {Scheme Variable} slim-service-type
14273 This is the type for the SLiM graphical login manager for X11.
14275 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14276 allows users to choose a session from the log-in screen using @kbd{F1}. It
14277 also honors @file{~/.xsession} files.
14279 Unlike GDM, SLiM does not spawn the user session on a different VT after
14280 logging in, which means that you can only start one graphical session. If you
14281 want to be able to run multiple graphical sessions at the same time you have
14282 to add multiple SLiM services to your system services. The following example
14283 shows how to replace the default GDM service with two SLiM services on tty7
14287 (use-modules (gnu services)
14288 (gnu services desktop)
14289 (gnu services xorg)
14290 (srfi srfi-1)) ;for 'remove'
14294 (services (cons* (service slim-service-type (slim-configuration
14297 (service slim-service-type (slim-configuration
14300 (remove (lambda (service)
14301 (eq? (service-kind service) gdm-service-type))
14302 %desktop-services))))
14307 @deftp {Data Type} slim-configuration
14308 Data type representing the configuration of @code{slim-service-type}.
14311 @item @code{allow-empty-passwords?} (default: @code{#t})
14312 Whether to allow logins with empty passwords.
14314 @item @code{auto-login?} (default: @code{#f})
14315 @itemx @code{default-user} (default: @code{""})
14316 When @code{auto-login?} is false, SLiM presents a log-in screen.
14318 When @code{auto-login?} is true, SLiM logs in directly as
14319 @code{default-user}.
14321 @item @code{theme} (default: @code{%default-slim-theme})
14322 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14323 The graphical theme to use and its name.
14325 @item @code{auto-login-session} (default: @code{#f})
14326 If true, this must be the name of the executable to start as the default
14327 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14329 If false, a session described by one of the available @file{.desktop}
14330 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14334 You must install at least one window manager in the system profile or in
14335 your user profile. Failing to do that, if @code{auto-login-session} is
14336 false, you will be unable to log in.
14339 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14340 Configuration of the Xorg graphical server.
14342 @item @code{display} (default @code{":0"})
14343 The display on which to start the Xorg graphical server.
14345 @item @code{vt} (default @code{"vt7"})
14346 The VT on which to start the Xorg graphical server.
14348 @item @code{xauth} (default: @code{xauth})
14349 The XAuth package to use.
14351 @item @code{shepherd} (default: @code{shepherd})
14352 The Shepherd package used when invoking @command{halt} and
14355 @item @code{sessreg} (default: @code{sessreg})
14356 The sessreg package used in order to register the session.
14358 @item @code{slim} (default: @code{slim})
14359 The SLiM package to use.
14363 @defvr {Scheme Variable} %default-theme
14364 @defvrx {Scheme Variable} %default-theme-name
14365 The default SLiM theme and its name.
14369 @deftp {Data Type} sddm-configuration
14370 This is the data type representing the sddm service configuration.
14373 @item @code{display-server} (default: "x11")
14374 Select display server to use for the greeter. Valid values are "x11"
14377 @item @code{numlock} (default: "on")
14378 Valid values are "on", "off" or "none".
14380 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14381 Command to run when halting.
14383 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14384 Command to run when rebooting.
14386 @item @code{theme} (default "maldives")
14387 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
14389 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14390 Directory to look for themes.
14392 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14393 Directory to look for faces.
14395 @item @code{default-path} (default "/run/current-system/profile/bin")
14396 Default PATH to use.
14398 @item @code{minimum-uid} (default: 1000)
14399 Minimum UID displayed in SDDM and allowed for log-in.
14401 @item @code{maximum-uid} (default: 2000)
14402 Maximum UID to display in SDDM.
14404 @item @code{remember-last-user?} (default #t)
14405 Remember last user.
14407 @item @code{remember-last-session?} (default #t)
14408 Remember last session.
14410 @item @code{hide-users} (default "")
14411 Usernames to hide from SDDM greeter.
14413 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14414 Users with shells listed will be hidden from the SDDM greeter.
14416 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14417 Script to run before starting a wayland session.
14419 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14420 Directory to look for desktop files starting wayland sessions.
14422 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14423 Configuration of the Xorg graphical server.
14425 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14428 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14431 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14432 Script to run after starting xorg-server.
14434 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14435 Script to run before stopping xorg-server.
14437 @item @code{xsession-command} (default: @code{xinitrc})
14438 Script to run before starting a X session.
14440 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14441 Directory to look for desktop files starting X sessions.
14443 @item @code{minimum-vt} (default: 7)
14446 @item @code{auto-login-user} (default "")
14447 User to use for auto-login.
14449 @item @code{auto-login-session} (default "")
14450 Desktop file to use for auto-login.
14452 @item @code{relogin?} (default #f)
14453 Relogin after logout.
14458 @cindex login manager
14460 @defvr {Scheme Variable} sddm-service-type
14461 This is the type of the service to run the
14462 @uref{https://github.com/sddm/sddm,SSDM display manager}. Its value
14463 must be a @code{sddm-configuration} record (see below).
14465 Here's an example use:
14468 (service sddm-service-type
14469 (sddm-configuration
14470 (auto-login-user "alice")
14471 (auto-login-session "xfce.desktop")))
14475 @deftp {Data Type} sddm-configuration
14476 This data type represents the configuration of the SDDM login manager.
14477 The available fields are:
14480 @item @code{sddm} (default: @code{sddm})
14481 The SDDM package to use.
14483 @item @code{display-server} (default: @code{"x11"})
14484 This must be either @code{"x11"} or @code{"wayland"}.
14486 @c FIXME: Add more fields.
14488 @item @code{auto-login-user} (default: @code{""})
14489 If non-empty, this is the user account under which to log in
14492 @item @code{auto-login-session} (default: @code{""})
14493 If non-empty, this is the @file{.desktop} file name to use as the
14494 auto-login session.
14498 @cindex Xorg, configuration
14499 @deftp {Data Type} xorg-configuration
14500 This data type represents the configuration of the Xorg graphical display
14501 server. Note that there is not Xorg service; instead, the X server is started
14502 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14503 of these display managers aggregates an @code{xorg-configuration} record.
14506 @item @code{modules} (default: @code{%default-xorg-modules})
14507 This is a list of @dfn{module packages} loaded by the Xorg
14508 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14510 @item @code{fonts} (default: @code{%default-xorg-fonts})
14511 This is a list of font directories to add to the server's @dfn{font path}.
14513 @item @code{drivers} (default: @code{'()})
14514 This must be either the empty list, in which case Xorg chooses a graphics
14515 driver automatically, or a list of driver names that will be tried in this
14516 order---e.g., @code{("modesetting" "vesa")}.
14518 @item @code{resolutions} (default: @code{'()})
14519 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14520 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14523 @cindex keyboard layout, for Xorg
14524 @cindex keymap, for Xorg
14525 @item @code{keyboard-layout} (default: @code{#f})
14526 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14527 English (``qwerty'') for a 105-key PC keyboard.
14529 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14530 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14531 information on how to specify the keyboard layout.
14533 @item @code{extra-config} (default: @code{'()})
14534 This is a list of strings or objects appended to the configuration file. It
14535 is used to pass extra text to be added verbatim to the configuration file.
14537 @item @code{server} (default: @code{xorg-server})
14538 This is the package providing the Xorg server.
14540 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14541 This is the list of command-line arguments to pass to the X server. The
14542 default is @code{-nolisten tcp}.
14546 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14547 [@var{login-manager-service-type}]
14548 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14549 @var{config}, an @code{<xorg-configuration>} record.
14551 Since the Xorg configuration is embedded in the log-in manager's
14552 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14553 shorthand to set the Xorg configuration.
14556 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14557 Return a @code{startx} script in which the modules, fonts, etc. specified
14558 in @var{config}, are available. The result should be used in place of
14561 Usually the X server is started by a login manager.
14565 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14566 Add @var{package}, a package for a screen locker or screen saver whose
14567 command is @var{program}, to the set of setuid programs and add a PAM entry
14568 for it. For example:
14571 (screen-locker-service xlockmore "xlock")
14574 makes the good ol' XlockMore usable.
14578 @node Printing Services
14579 @subsection Printing Services
14581 @cindex printer support with CUPS
14582 The @code{(gnu services cups)} module provides a Guix service definition
14583 for the CUPS printing service. To add printer support to a Guix
14584 system, add a @code{cups-service} to the operating system definition:
14586 @deffn {Scheme Variable} cups-service-type
14587 The service type for the CUPS print server. Its value should be a valid
14588 CUPS configuration (see below). To use the default settings, simply
14591 (service cups-service-type)
14595 The CUPS configuration controls the basic things about your CUPS
14596 installation: what interfaces it listens on, what to do if a print job
14597 fails, how much logging to do, and so on. To actually add a printer,
14598 you have to visit the @url{http://localhost:631} URL, or use a tool such
14599 as GNOME's printer configuration services. By default, configuring a
14600 CUPS service will generate a self-signed certificate if needed, for
14601 secure connections to the print server.
14603 Suppose you want to enable the Web interface of CUPS and also add
14604 support for Epson printers @i{via} the @code{escpr} package and for HP
14605 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14606 like this (you need to use the @code{(gnu packages cups)} module):
14609 (service cups-service-type
14610 (cups-configuration
14611 (web-interface? #t)
14613 (list cups-filters escpr hplip-minimal))))
14616 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14617 package then it is suggested that you install the @code{hplip} package,
14618 either in your OS configuration file or as your user.
14620 The available configuration parameters follow. Each parameter
14621 definition is preceded by its type; for example, @samp{string-list foo}
14622 indicates that the @code{foo} parameter should be specified as a list of
14623 strings. There is also a way to specify the configuration as a string,
14624 if you have an old @code{cupsd.conf} file that you want to port over
14625 from some other system; see the end for more details.
14627 @c The following documentation was initially generated by
14628 @c (generate-documentation) in (gnu services cups). Manually maintained
14629 @c documentation is better, so we shouldn't hesitate to edit below as
14630 @c needed. However if the change you want to make to this documentation
14631 @c can be done in an automated way, it's probably easier to change
14632 @c (generate-documentation) than to make it below and have to deal with
14633 @c the churn as CUPS updates.
14636 Available @code{cups-configuration} fields are:
14638 @deftypevr {@code{cups-configuration} parameter} package cups
14642 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14643 Drivers and other extensions to the CUPS package.
14646 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14647 Configuration of where to write logs, what directories to use for print
14648 spools, and related privileged configuration parameters.
14650 Available @code{files-configuration} fields are:
14652 @deftypevr {@code{files-configuration} parameter} log-location access-log
14653 Defines the access log filename. Specifying a blank filename disables
14654 access log generation. The value @code{stderr} causes log entries to be
14655 sent to the standard error file when the scheduler is running in the
14656 foreground, or to the system log daemon when run in the background. The
14657 value @code{syslog} causes log entries to be sent to the system log
14658 daemon. The server name may be included in filenames using the string
14659 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14661 Defaults to @samp{"/var/log/cups/access_log"}.
14664 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14665 Where CUPS should cache data.
14667 Defaults to @samp{"/var/cache/cups"}.
14670 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14671 Specifies the permissions for all configuration files that the scheduler
14674 Note that the permissions for the printers.conf file are currently
14675 masked to only allow access from the scheduler user (typically root).
14676 This is done because printer device URIs sometimes contain sensitive
14677 authentication information that should not be generally known on the
14678 system. There is no way to disable this security feature.
14680 Defaults to @samp{"0640"}.
14683 @deftypevr {@code{files-configuration} parameter} log-location error-log
14684 Defines the error log filename. Specifying a blank filename disables
14685 error log generation. The value @code{stderr} causes log entries to be
14686 sent to the standard error file when the scheduler is running in the
14687 foreground, or to the system log daemon when run in the background. The
14688 value @code{syslog} causes log entries to be sent to the system log
14689 daemon. The server name may be included in filenames using the string
14690 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14692 Defaults to @samp{"/var/log/cups/error_log"}.
14695 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14696 Specifies which errors are fatal, causing the scheduler to exit. The
14701 No errors are fatal.
14704 All of the errors below are fatal.
14707 Browsing initialization errors are fatal, for example failed connections
14708 to the DNS-SD daemon.
14711 Configuration file syntax errors are fatal.
14714 Listen or Port errors are fatal, except for IPv6 failures on the
14715 loopback or @code{any} addresses.
14718 Log file creation or write errors are fatal.
14721 Bad startup file permissions are fatal, for example shared TLS
14722 certificate and key files with world-read permissions.
14725 Defaults to @samp{"all -browse"}.
14728 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14729 Specifies whether the file pseudo-device can be used for new printer
14730 queues. The URI @uref{file:///dev/null} is always allowed.
14732 Defaults to @samp{#f}.
14735 @deftypevr {@code{files-configuration} parameter} string group
14736 Specifies the group name or ID that will be used when executing external
14739 Defaults to @samp{"lp"}.
14742 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14743 Specifies the permissions for all log files that the scheduler writes.
14745 Defaults to @samp{"0644"}.
14748 @deftypevr {@code{files-configuration} parameter} log-location page-log
14749 Defines the page log filename. Specifying a blank filename disables
14750 page log generation. The value @code{stderr} causes log entries to be
14751 sent to the standard error file when the scheduler is running in the
14752 foreground, or to the system log daemon when run in the background. The
14753 value @code{syslog} causes log entries to be sent to the system log
14754 daemon. The server name may be included in filenames using the string
14755 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14757 Defaults to @samp{"/var/log/cups/page_log"}.
14760 @deftypevr {@code{files-configuration} parameter} string remote-root
14761 Specifies the username that is associated with unauthenticated accesses
14762 by clients claiming to be the root user. The default is @code{remroot}.
14764 Defaults to @samp{"remroot"}.
14767 @deftypevr {@code{files-configuration} parameter} file-name request-root
14768 Specifies the directory that contains print jobs and other HTTP request
14771 Defaults to @samp{"/var/spool/cups"}.
14774 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14775 Specifies the level of security sandboxing that is applied to print
14776 filters, backends, and other child processes of the scheduler; either
14777 @code{relaxed} or @code{strict}. This directive is currently only
14778 used/supported on macOS.
14780 Defaults to @samp{strict}.
14783 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14784 Specifies the location of TLS certificates and private keys. CUPS will
14785 look for public and private keys in this directory: a @code{.crt} files
14786 for PEM-encoded certificates and corresponding @code{.key} files for
14787 PEM-encoded private keys.
14789 Defaults to @samp{"/etc/cups/ssl"}.
14792 @deftypevr {@code{files-configuration} parameter} file-name server-root
14793 Specifies the directory containing the server configuration files.
14795 Defaults to @samp{"/etc/cups"}.
14798 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14799 Specifies whether the scheduler calls fsync(2) after writing
14800 configuration or state files.
14802 Defaults to @samp{#f}.
14805 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14806 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14809 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14810 Specifies the directory where temporary files are stored.
14812 Defaults to @samp{"/var/spool/cups/tmp"}.
14815 @deftypevr {@code{files-configuration} parameter} string user
14816 Specifies the user name or ID that is used when running external
14819 Defaults to @samp{"lp"}.
14822 @deftypevr {@code{files-configuration} parameter} string set-env
14823 Set the specified environment variable to be passed to child processes.
14825 Defaults to @samp{"variable value"}.
14829 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14830 Specifies the logging level for the AccessLog file. The @code{config}
14831 level logs when printers and classes are added, deleted, or modified and
14832 when configuration files are accessed or updated. The @code{actions}
14833 level logs when print jobs are submitted, held, released, modified, or
14834 canceled, and any of the conditions for @code{config}. The @code{all}
14835 level logs all requests.
14837 Defaults to @samp{actions}.
14840 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14841 Specifies whether to purge job history data automatically when it is no
14842 longer required for quotas.
14844 Defaults to @samp{#f}.
14847 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
14848 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
14849 For example, @samp{"_cups" "_print"} will tell network clients that both
14850 CUPS sharing and IPP Everywhere are supported.
14852 Defaults to @samp{"_cups"}.
14855 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14856 Specifies which protocols to use for local printer sharing.
14858 Defaults to @samp{dnssd}.
14861 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14862 Specifies whether the CUPS web interface is advertised.
14864 Defaults to @samp{#f}.
14867 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14868 Specifies whether shared printers are advertised.
14870 Defaults to @samp{#f}.
14873 @deftypevr {@code{cups-configuration} parameter} string classification
14874 Specifies the security classification of the server. Any valid banner
14875 name can be used, including "classified", "confidential", "secret",
14876 "topsecret", and "unclassified", or the banner can be omitted to disable
14877 secure printing functions.
14879 Defaults to @samp{""}.
14882 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14883 Specifies whether users may override the classification (cover page) of
14884 individual print jobs using the @code{job-sheets} option.
14886 Defaults to @samp{#f}.
14889 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14890 Specifies the default type of authentication to use.
14892 Defaults to @samp{Basic}.
14895 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14896 Specifies whether encryption will be used for authenticated requests.
14898 Defaults to @samp{Required}.
14901 @deftypevr {@code{cups-configuration} parameter} string default-language
14902 Specifies the default language to use for text and web content.
14904 Defaults to @samp{"en"}.
14907 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14908 Specifies the default paper size for new print queues. @samp{"Auto"}
14909 uses a locale-specific default, while @samp{"None"} specifies there is
14910 no default paper size. Specific size names are typically
14911 @samp{"Letter"} or @samp{"A4"}.
14913 Defaults to @samp{"Auto"}.
14916 @deftypevr {@code{cups-configuration} parameter} string default-policy
14917 Specifies the default access policy to use.
14919 Defaults to @samp{"default"}.
14922 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14923 Specifies whether local printers are shared by default.
14925 Defaults to @samp{#t}.
14928 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14929 Specifies the delay for updating of configuration and state files, in
14930 seconds. A value of 0 causes the update to happen as soon as possible,
14931 typically within a few milliseconds.
14933 Defaults to @samp{30}.
14936 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14937 Specifies what to do when an error occurs. Possible values are
14938 @code{abort-job}, which will discard the failed print job;
14939 @code{retry-job}, which will retry the job at a later time;
14940 @code{retry-current-job}, which retries the failed job immediately; and
14941 @code{stop-printer}, which stops the printer.
14943 Defaults to @samp{stop-printer}.
14946 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14947 Specifies the maximum cost of filters that are run concurrently, which
14948 can be used to minimize disk, memory, and CPU resource problems. A
14949 limit of 0 disables filter limiting. An average print to a
14950 non-PostScript printer needs a filter limit of about 200. A PostScript
14951 printer needs about half that (100). Setting the limit below these
14952 thresholds will effectively limit the scheduler to printing a single job
14955 Defaults to @samp{0}.
14958 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14959 Specifies the scheduling priority of filters that are run to print a
14960 job. The nice value ranges from 0, the highest priority, to 19, the
14963 Defaults to @samp{0}.
14966 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14967 Specifies whether to do reverse lookups on connecting clients. The
14968 @code{double} setting causes @code{cupsd} to verify that the hostname
14969 resolved from the address matches one of the addresses returned for that
14970 hostname. Double lookups also prevent clients with unregistered
14971 addresses from connecting to your server. Only set this option to
14972 @code{#t} or @code{double} if absolutely required.
14974 Defaults to @samp{#f}.
14977 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14978 Specifies the number of seconds to wait before killing the filters and
14979 backend associated with a canceled or held job.
14981 Defaults to @samp{30}.
14984 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14985 Specifies the interval between retries of jobs in seconds. This is
14986 typically used for fax queues but can also be used with normal print
14987 queues whose error policy is @code{retry-job} or
14988 @code{retry-current-job}.
14990 Defaults to @samp{30}.
14993 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14994 Specifies the number of retries that are done for jobs. This is
14995 typically used for fax queues but can also be used with normal print
14996 queues whose error policy is @code{retry-job} or
14997 @code{retry-current-job}.
14999 Defaults to @samp{5}.
15002 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
15003 Specifies whether to support HTTP keep-alive connections.
15005 Defaults to @samp{#t}.
15008 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
15009 Specifies how long an idle client connection remains open, in seconds.
15011 Defaults to @samp{30}.
15014 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
15015 Specifies the maximum size of print files, IPP requests, and HTML form
15016 data. A limit of 0 disables the limit check.
15018 Defaults to @samp{0}.
15021 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
15022 Listens on the specified interfaces for connections. Valid values are
15023 of the form @var{address}:@var{port}, where @var{address} is either an
15024 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
15025 indicate all addresses. Values can also be file names of local UNIX
15026 domain sockets. The Listen directive is similar to the Port directive
15027 but allows you to restrict access to specific interfaces or networks.
15030 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
15031 Specifies the number of pending connections that will be allowed. This
15032 normally only affects very busy servers that have reached the MaxClients
15033 limit, but can also be triggered by large numbers of simultaneous
15034 connections. When the limit is reached, the operating system will
15035 refuse additional connections until the scheduler can accept the pending
15038 Defaults to @samp{128}.
15041 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
15042 Specifies a set of additional access controls.
15044 Available @code{location-access-controls} fields are:
15046 @deftypevr {@code{location-access-controls} parameter} file-name path
15047 Specifies the URI path to which the access control applies.
15050 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
15051 Access controls for all access to this path, in the same format as the
15052 @code{access-controls} of @code{operation-access-control}.
15054 Defaults to @samp{()}.
15057 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
15058 Access controls for method-specific access to this path.
15060 Defaults to @samp{()}.
15062 Available @code{method-access-controls} fields are:
15064 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
15065 If @code{#t}, apply access controls to all methods except the listed
15066 methods. Otherwise apply to only the listed methods.
15068 Defaults to @samp{#f}.
15071 @deftypevr {@code{method-access-controls} parameter} method-list methods
15072 Methods to which this access control applies.
15074 Defaults to @samp{()}.
15077 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
15078 Access control directives, as a list of strings. Each string should be
15079 one directive, such as "Order allow,deny".
15081 Defaults to @samp{()}.
15086 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15087 Specifies the number of debugging messages that are retained for logging
15088 if an error occurs in a print job. Debug messages are logged regardless
15089 of the LogLevel setting.
15091 Defaults to @samp{100}.
15094 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15095 Specifies the level of logging for the ErrorLog file. The value
15096 @code{none} stops all logging while @code{debug2} logs everything.
15098 Defaults to @samp{info}.
15101 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15102 Specifies the format of the date and time in the log files. The value
15103 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15105 Defaults to @samp{standard}.
15108 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15109 Specifies the maximum number of simultaneous clients that are allowed by
15112 Defaults to @samp{100}.
15115 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15116 Specifies the maximum number of simultaneous clients that are allowed
15117 from a single address.
15119 Defaults to @samp{100}.
15122 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15123 Specifies the maximum number of copies that a user can print of each
15126 Defaults to @samp{9999}.
15129 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15130 Specifies the maximum time a job may remain in the @code{indefinite}
15131 hold state before it is canceled. A value of 0 disables cancellation of
15134 Defaults to @samp{0}.
15137 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15138 Specifies the maximum number of simultaneous jobs that are allowed. Set
15139 to 0 to allow an unlimited number of jobs.
15141 Defaults to @samp{500}.
15144 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15145 Specifies the maximum number of simultaneous jobs that are allowed per
15146 printer. A value of 0 allows up to MaxJobs jobs per printer.
15148 Defaults to @samp{0}.
15151 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15152 Specifies the maximum number of simultaneous jobs that are allowed per
15153 user. A value of 0 allows up to MaxJobs jobs per user.
15155 Defaults to @samp{0}.
15158 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15159 Specifies the maximum time a job may take to print before it is
15160 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
15162 Defaults to @samp{10800}.
15165 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15166 Specifies the maximum size of the log files before they are rotated, in
15167 bytes. The value 0 disables log rotation.
15169 Defaults to @samp{1048576}.
15172 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15173 Specifies the maximum amount of time to allow between files in a
15174 multiple file print job, in seconds.
15176 Defaults to @samp{300}.
15179 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15180 Specifies the format of PageLog lines. Sequences beginning with percent
15181 (@samp{%}) characters are replaced with the corresponding information,
15182 while all other characters are copied literally. The following percent
15183 sequences are recognized:
15187 insert a single percent character
15190 insert the value of the specified IPP attribute
15193 insert the number of copies for the current page
15196 insert the current page number
15199 insert the current date and time in common log format
15205 insert the printer name
15208 insert the username
15211 A value of the empty string disables page logging. The string @code{%p
15212 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15213 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15216 Defaults to @samp{""}.
15219 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15220 Passes the specified environment variable(s) to child processes; a list
15223 Defaults to @samp{()}.
15226 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15227 Specifies named access control policies.
15229 Available @code{policy-configuration} fields are:
15231 @deftypevr {@code{policy-configuration} parameter} string name
15232 Name of the policy.
15235 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15236 Specifies an access list for a job's private values. @code{@@ACL} maps
15237 to the printer's requesting-user-name-allowed or
15238 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15239 owner. @code{@@SYSTEM} maps to the groups listed for the
15240 @code{system-group} field of the @code{files-config} configuration,
15241 which is reified into the @code{cups-files.conf(5)} file. Other
15242 possible elements of the access list include specific user names, and
15243 @code{@@@var{group}} to indicate members of a specific group. The
15244 access list may also be simply @code{all} or @code{default}.
15246 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15249 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15250 Specifies the list of job values to make private, or @code{all},
15251 @code{default}, or @code{none}.
15253 Defaults to @samp{"job-name job-originating-host-name
15254 job-originating-user-name phone"}.
15257 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15258 Specifies an access list for a subscription's private values.
15259 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15260 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15261 owner. @code{@@SYSTEM} maps to the groups listed for the
15262 @code{system-group} field of the @code{files-config} configuration,
15263 which is reified into the @code{cups-files.conf(5)} file. Other
15264 possible elements of the access list include specific user names, and
15265 @code{@@@var{group}} to indicate members of a specific group. The
15266 access list may also be simply @code{all} or @code{default}.
15268 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15271 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15272 Specifies the list of job values to make private, or @code{all},
15273 @code{default}, or @code{none}.
15275 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15276 notify-subscriber-user-name notify-user-data"}.
15279 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15280 Access control by IPP operation.
15282 Defaults to @samp{()}.
15286 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15287 Specifies whether job files (documents) are preserved after a job is
15288 printed. If a numeric value is specified, job files are preserved for
15289 the indicated number of seconds after printing. Otherwise a boolean
15290 value applies indefinitely.
15292 Defaults to @samp{86400}.
15295 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15296 Specifies whether the job history is preserved after a job is printed.
15297 If a numeric value is specified, the job history is preserved for the
15298 indicated number of seconds after printing. If @code{#t}, the job
15299 history is preserved until the MaxJobs limit is reached.
15301 Defaults to @samp{#t}.
15304 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15305 Specifies the amount of time to wait for job completion before
15306 restarting the scheduler.
15308 Defaults to @samp{30}.
15311 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15312 Specifies the maximum amount of memory to use when converting documents
15313 into bitmaps for a printer.
15315 Defaults to @samp{"128m"}.
15318 @deftypevr {@code{cups-configuration} parameter} string server-admin
15319 Specifies the email address of the server administrator.
15321 Defaults to @samp{"root@@localhost.localdomain"}.
15324 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15325 The ServerAlias directive is used for HTTP Host header validation when
15326 clients connect to the scheduler from external interfaces. Using the
15327 special name @code{*} can expose your system to known browser-based DNS
15328 rebinding attacks, even when accessing sites through a firewall. If the
15329 auto-discovery of alternate names does not work, we recommend listing
15330 each alternate name with a ServerAlias directive instead of using
15333 Defaults to @samp{*}.
15336 @deftypevr {@code{cups-configuration} parameter} string server-name
15337 Specifies the fully-qualified host name of the server.
15339 Defaults to @samp{"localhost"}.
15342 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15343 Specifies what information is included in the Server header of HTTP
15344 responses. @code{None} disables the Server header. @code{ProductOnly}
15345 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15346 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15347 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15348 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15349 2.0.0 (@var{uname}) IPP/2.0}.
15351 Defaults to @samp{Minimal}.
15354 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15355 Listens on the specified interfaces for encrypted connections. Valid
15356 values are of the form @var{address}:@var{port}, where @var{address} is
15357 either an IPv6 address enclosed in brackets, an IPv4 address, or
15358 @code{*} to indicate all addresses.
15360 Defaults to @samp{()}.
15363 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15364 Sets encryption options. By default, CUPS only supports encryption
15365 using TLS v1.0 or higher using known secure cipher suites. Security is
15366 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15367 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15368 suites, which are required for some older clients. The @code{AllowSSL3} option
15369 enables SSL v3.0, which is required for some older clients that do not support
15370 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15371 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15372 protocol version to TLS v1.1.
15374 Defaults to @samp{()}.
15377 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15378 Specifies whether the scheduler requires clients to strictly adhere to
15379 the IPP specifications.
15381 Defaults to @samp{#f}.
15384 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15385 Specifies the HTTP request timeout, in seconds.
15387 Defaults to @samp{300}.
15391 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15392 Specifies whether the web interface is enabled.
15394 Defaults to @samp{#f}.
15397 At this point you're probably thinking ``oh dear, Guix manual, I like
15398 you but you can stop already with the configuration options''. Indeed.
15399 However, one more point: it could be that you have an existing
15400 @code{cupsd.conf} that you want to use. In that case, you can pass an
15401 @code{opaque-cups-configuration} as the configuration of a
15402 @code{cups-service-type}.
15404 Available @code{opaque-cups-configuration} fields are:
15406 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15410 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15411 The contents of the @code{cupsd.conf}, as a string.
15414 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15415 The contents of the @code{cups-files.conf} file, as a string.
15418 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15419 strings of the same name, you could instantiate a CUPS service like
15423 (service cups-service-type
15424 (opaque-cups-configuration
15425 (cupsd.conf cupsd.conf)
15426 (cups-files.conf cups-files.conf)))
15430 @node Desktop Services
15431 @subsection Desktop Services
15433 The @code{(gnu services desktop)} module provides services that are
15434 usually useful in the context of a ``desktop'' setup---that is, on a
15435 machine running a graphical display server, possibly with graphical user
15436 interfaces, etc. It also defines services that provide specific desktop
15437 environments like GNOME, Xfce or MATE.
15439 To simplify things, the module defines a variable containing the set of
15440 services that users typically expect on a machine with a graphical
15441 environment and networking:
15443 @defvr {Scheme Variable} %desktop-services
15444 This is a list of services that builds upon @code{%base-services} and
15445 adds or adjusts services for a typical ``desktop'' setup.
15447 In particular, it adds a graphical login manager (@pxref{X Window,
15448 @code{gdm-service-type}}), screen lockers, a network management tool
15449 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15450 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15451 energy and color management services, the @code{elogind} login and seat
15452 manager, the Polkit privilege service, the GeoClue location service, the
15453 AccountsService daemon that allows authorized users change system passwords,
15454 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15455 name service switch service configured to be able to use @code{nss-mdns}
15456 (@pxref{Name Service Switch, mDNS}).
15459 The @code{%desktop-services} variable can be used as the @code{services}
15460 field of an @code{operating-system} declaration (@pxref{operating-system
15461 Reference, @code{services}}).
15463 Additionally, the @code{gnome-desktop-service-type},
15464 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15465 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15466 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15467 services like the backlight adjustment helpers and the power management
15468 utilities are added to the system, extending @code{polkit} and @code{dbus}
15469 appropriately, allowing GNOME to operate with elevated privileges on a
15470 limited number of special-purpose system interfaces. Additionally,
15471 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15472 metapackage to the system profile. Likewise, adding the Xfce service
15473 not only adds the @code{xfce} metapackage to the system profile, but it
15474 also gives the Thunar file manager the ability to open a ``root-mode''
15475 file management window, if the user authenticates using the
15476 administrator's password via the standard polkit graphical interface.
15477 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15478 appropriately, allowing MATE to operate with elevated privileges on a
15479 limited number of special-purpose system interfaces. Additionally,
15480 adding a service of type @code{mate-desktop-service-type} adds the MATE
15481 metapackage to the system profile. ``Adding Enlightenment'' means that
15482 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15483 are set as setuid, allowing Enlightenment's screen locker and other
15484 functionality to work as expetected.
15486 The desktop environments in Guix use the Xorg display server by
15487 default. If you'd like to use the newer display server protocol
15488 called Wayland, you need to use the @code{sddm-service} instead of
15489 GDM as the graphical login manager. You should then
15490 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15491 also try starting GNOME on Wayland manually from a TTY with the
15492 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15493 gnome-session``. Currently only GNOME has support for Wayland.
15495 @defvr {Scheme Variable} gnome-desktop-service-type
15496 This is the type of the service that adds the @uref{https://www.gnome.org,
15497 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15498 object (see below.)
15500 This service adds the @code{gnome} package to the system profile, and extends
15501 polkit with the actions from @code{gnome-settings-daemon}.
15504 @deftp {Data Type} gnome-desktop-configuration
15505 Configuration record for the GNOME desktop environment.
15508 @item @code{gnome} (default: @code{gnome})
15509 The GNOME package to use.
15513 @defvr {Scheme Variable} xfce-desktop-service-type
15514 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15515 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15518 This service adds the @code{xfce} package to the system profile, and
15519 extends polkit with the ability for @code{thunar} to manipulate the file
15520 system as root from within a user session, after the user has authenticated
15521 with the administrator's password.
15524 @deftp {Data Type} xfce-desktop-configuration
15525 Configuration record for the Xfce desktop environment.
15528 @item @code{xfce} (default: @code{xfce})
15529 The Xfce package to use.
15533 @deffn {Scheme Variable} mate-desktop-service-type
15534 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15535 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15536 object (see below.)
15538 This service adds the @code{mate} package to the system
15539 profile, and extends polkit with the actions from
15540 @code{mate-settings-daemon}.
15543 @deftp {Data Type} mate-desktop-configuration
15544 Configuration record for the MATE desktop environment.
15547 @item @code{mate} (default: @code{mate})
15548 The MATE package to use.
15552 @deffn {Scheme Variable} enlightenment-desktop-service-type
15553 Return a service that adds the @code{enlightenment} package to the system
15554 profile, and extends dbus with actions from @code{efl}.
15557 @deftp {Data Type} enlightenment-desktop-service-configuration
15559 @item @code{enlightenment} (default: @code{enlightenment})
15560 The enlightenment package to use.
15564 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15565 the default @code{%desktop-services} variable doesn't include any of
15566 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15567 @code{%desktop-services} in the @code{services} field of your
15568 @code{operating-system}:
15571 (use-modules (gnu))
15572 (use-service-modules desktop)
15575 ;; cons* adds items to the list given as its last argument.
15576 (services (cons* (service gnome-desktop-service-type)
15577 (service xfce-desktop-service)
15578 %desktop-services))
15582 These desktop environments will then be available as options in the
15583 graphical login window.
15585 The actual service definitions included in @code{%desktop-services} and
15586 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15587 are described below.
15589 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
15590 Return a service that runs the ``system bus'', using @var{dbus}, with
15591 support for @var{services}.
15593 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
15594 facility. Its system bus is used to allow system services to communicate
15595 and to be notified of system-wide events.
15597 @var{services} must be a list of packages that provide an
15598 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
15599 and policy files. For example, to allow avahi-daemon to use the system bus,
15600 @var{services} must be equal to @code{(list avahi)}.
15603 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
15604 Return a service that runs the @code{elogind} login and
15605 seat management daemon. @uref{https://github.com/elogind/elogind,
15606 Elogind} exposes a D-Bus interface that can be used to know which users
15607 are logged in, know what kind of sessions they have open, suspend the
15608 system, inhibit system suspend, reboot the system, and other tasks.
15610 Elogind handles most system-level power events for a computer, for
15611 example suspending the system when a lid is closed, or shutting it down
15612 when the power button is pressed.
15614 The @var{config} keyword argument specifies the configuration for
15615 elogind, and should be the result of an @code{(elogind-configuration
15616 (@var{parameter} @var{value})...)} invocation. Available parameters and
15617 their default values are:
15620 @item kill-user-processes?
15622 @item kill-only-users
15624 @item kill-exclude-users
15626 @item inhibit-delay-max-seconds
15628 @item handle-power-key
15630 @item handle-suspend-key
15632 @item handle-hibernate-key
15634 @item handle-lid-switch
15636 @item handle-lid-switch-docked
15638 @item power-key-ignore-inhibited?
15640 @item suspend-key-ignore-inhibited?
15642 @item hibernate-key-ignore-inhibited?
15644 @item lid-switch-ignore-inhibited?
15646 @item holdoff-timeout-seconds
15650 @item idle-action-seconds
15652 @item runtime-directory-size-percent
15654 @item runtime-directory-size
15658 @item suspend-state
15659 @code{("mem" "standby" "freeze")}
15662 @item hibernate-state
15664 @item hibernate-mode
15665 @code{("platform" "shutdown")}
15666 @item hybrid-sleep-state
15668 @item hybrid-sleep-mode
15669 @code{("suspend" "platform" "shutdown")}
15673 @deffn {Scheme Procedure} accountsservice-service @
15674 [#:accountsservice @var{accountsservice}]
15675 Return a service that runs AccountsService, a system service that can
15676 list available accounts, change their passwords, and so on.
15677 AccountsService integrates with PolicyKit to enable unprivileged users
15678 to acquire the capability to modify their system configuration.
15679 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15680 accountsservice web site} for more information.
15682 The @var{accountsservice} keyword argument is the @code{accountsservice}
15683 package to expose as a service.
15686 @deffn {Scheme Procedure} polkit-service @
15687 [#:polkit @var{polkit}]
15688 Return a service that runs the
15689 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15690 management service}, which allows system administrators to grant access to
15691 privileged operations in a structured way. By querying the Polkit service, a
15692 privileged system component can know when it should grant additional
15693 capabilities to ordinary users. For example, an ordinary user can be granted
15694 the capability to suspend the system if the user is logged in locally.
15697 @defvr {Scheme Variable} polkit-wheel-service
15698 Service that adds the @code{wheel} group as admins to the Polkit
15699 service. This makes it so that users in the @code{wheel} group are queried
15700 for their own passwords when performing administrative actions instead of
15701 @code{root}'s, similar to the behaviour used by @code{sudo}.
15704 @defvr {Scheme Variable} upower-service-type
15705 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15706 system-wide monitor for power consumption and battery levels, with the given
15707 configuration settings.
15709 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15710 notably used by GNOME.
15713 @deftp {Data Type} upower-configuration
15714 Data type representation the configuration for UPower.
15718 @item @code{upower} (default: @var{upower})
15719 Package to use for @code{upower}.
15721 @item @code{watts-up-pro?} (default: @code{#f})
15722 Enable the Watts Up Pro device.
15724 @item @code{poll-batteries?} (default: @code{#t})
15725 Enable polling the kernel for battery level changes.
15727 @item @code{ignore-lid?} (default: @code{#f})
15728 Ignore the lid state, this can be useful if it's incorrect on a device.
15730 @item @code{use-percentage-for-policy?} (default: @code{#f})
15731 Whether battery percentage based policy should be used. The default is to use
15732 the time left, change to @code{#t} to use the percentage.
15734 @item @code{percentage-low} (default: @code{10})
15735 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15736 at which the battery is considered low.
15738 @item @code{percentage-critical} (default: @code{3})
15739 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15740 at which the battery is considered critical.
15742 @item @code{percentage-action} (default: @code{2})
15743 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15744 at which action will be taken.
15746 @item @code{time-low} (default: @code{1200})
15747 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15748 seconds at which the battery is considered low.
15750 @item @code{time-critical} (default: @code{300})
15751 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15752 seconds at which the battery is considered critical.
15754 @item @code{time-action} (default: @code{120})
15755 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15756 seconds at which action will be taken.
15758 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15759 The action taken when @code{percentage-action} or @code{time-action} is
15760 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15762 Possible values are:
15772 @code{'hybrid-sleep}.
15778 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15779 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15780 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15781 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15782 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15785 @deffn {Scheme Variable} colord-service-type
15786 This is the type of the service that runs @command{colord}, a system
15787 service with a D-Bus
15788 interface to manage the color profiles of input and output devices such as
15789 screens and scanners. It is notably used by the GNOME Color Manager graphical
15790 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15791 site} for more information.
15794 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15795 Return a configuration allowing an application to access GeoClue
15796 location data. @var{name} is the Desktop ID of the application, without
15797 the @code{.desktop} part. If @var{allowed?} is true, the application
15798 will have access to location information by default. The boolean
15799 @var{system?} value indicates whether an application is a system component
15800 or not. Finally @var{users} is a list of UIDs of all users for which
15801 this application is allowed location info access. An empty users list
15802 means that all users are allowed.
15805 @defvr {Scheme Variable} %standard-geoclue-applications
15806 The standard list of well-known GeoClue application configurations,
15807 granting authority to the GNOME date-and-time utility to ask for the
15808 current location in order to set the time zone, and allowing the
15809 IceCat and Epiphany web browsers to request location information.
15810 IceCat and Epiphany both query the user before allowing a web page to
15811 know the user's location.
15814 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15815 [#:whitelist '()] @
15816 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15817 [#:submit-data? #f]
15818 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15819 [#:submission-nick "geoclue"] @
15820 [#:applications %standard-geoclue-applications]
15821 Return a service that runs the GeoClue location service. This service
15822 provides a D-Bus interface to allow applications to request access to a
15823 user's physical location, and optionally to add information to online
15824 location databases. See
15825 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15826 web site} for more information.
15829 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15830 [@w{#:auto-enable? #f}]
15831 Return a service that runs the @command{bluetoothd} daemon, which
15832 manages all the Bluetooth devices and provides a number of D-Bus
15833 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15834 powered automatically at boot, which can be useful when using a
15835 bluetooth keyboard or mouse.
15837 Users need to be in the @code{lp} group to access the D-Bus service.
15840 @defvr {Scheme Variable} gnome-keyring-service-type
15841 This is the type of the service that adds the
15842 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
15843 value is a @code{gnome-keyring-configuration} object (see below.)
15845 This service adds the @code{gnome-keyring} package to the system profile
15846 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
15847 a user's login keyring when they log in or setting its password with passwd.
15850 @deftp {Data Type} gnome-keyring-configuration
15851 Configuration record for the GNOME Keyring service.
15854 @item @code{keyring} (default: @code{gnome-keyring})
15855 The GNOME keyring package to use.
15857 @item @code{pam-services}
15858 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
15859 services to extend, where @var{service} is the name of an existing
15860 service to extend and @var{kind} is one of @code{login} or
15863 If @code{login} is given, it adds an optional
15864 @code{pam_gnome_keyring.so} to the auth block without arguments and to
15865 the session block with @code{auto_start}. If @code{passwd} is given, it
15866 adds an optional @code{pam_gnome_keyring.so} to the password block
15869 By default, this field contains ``gdm-password'' with the value @code{login}
15870 and ``passwd'' is with the value @code{passwd}.
15875 @node Sound Services
15876 @subsection Sound Services
15878 @cindex sound support
15880 @cindex PulseAudio, sound support
15882 The @code{(gnu services sound)} module provides a service to configure the
15883 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15884 preferred ALSA output driver.
15886 @deffn {Scheme Variable} alsa-service-type
15887 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15888 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15889 configuration file. The value for this type is a @command{alsa-configuration}
15890 record as in this example:
15893 (service alsa-service-type)
15896 See below for details about @code{alsa-configuration}.
15899 @deftp {Data Type} alsa-configuration
15900 Data type representing the configuration for @code{alsa-service}.
15903 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15904 @code{alsa-plugins} package to use.
15906 @item @code{pulseaudio?} (default: @var{#t})
15907 Whether ALSA applications should transparently be made to use the
15908 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15910 Using PulseAudio allows you to run several sound-producing applications
15911 at the same time and to individual control them @i{via}
15912 @command{pavucontrol}, among other things.
15914 @item @code{extra-options} (default: @var{""})
15915 String to append to the @file{/etc/asound.conf} file.
15920 Individual users who want to override the system configuration of ALSA can do
15921 it with the @file{~/.asoundrc} file:
15924 # In guix, we have to specify the absolute path for plugins.
15926 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15929 # Routing ALSA to jack:
15930 # <http://jackaudio.org/faq/routing_alsa.html>.
15934 0 system:playback_1
15935 1 system:playback_2
15952 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15955 @deffn {Scheme Variable} pulseaudio-service-type
15956 This is the type for the @uref{http://www.pulseaudio.org/, PulseAudio}
15957 sound server. It exists to allow system overrides of the default settings
15958 via @code{pulseaudio-configuration}, see below.
15961 This service on its own does not ensure, that the @code{pulseaudio} package
15962 exists on your machine. It merely adds configuration files for it, as
15963 detailed below. In the (admittedly unlikely) case, that you find yourself
15964 without a @code{pulseaudio} package, consider enabling it through the
15965 @code{alsa-service-type} above.
15969 @deftp {Data Type} pulseaudio-configuration
15970 Data type representing the configuration for @code{pulseaudio-service}.
15973 @item @var{client-conf} (default: @code{'()})
15974 List of settings to set in @file{client.conf}.
15975 Accepts a list of strings or a symbol-value pairs. A string will be
15976 inserted as-is with a newline added. A pair will be formatted as
15977 ``key = value'', again with a newline added.
15979 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
15980 List of settings to set in @file{daemon.conf}, formatted just like
15983 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
15984 Script file to use as as @file{default.pa}.
15986 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
15987 Script file to use as as @file{system.pa}.
15991 @deffn {Scheme Variable} ladspa-service-type
15992 This service sets the @var{LADSPA_PATH} variable, so that programs, which
15993 respect it, e.g. PulseAudio, can load LADSPA plugins.
15995 The following example will setup the service to enable modules from the
15996 @code{swh-plugins} package:
15999 (service ladspa-service-type
16000 (ladspa-configuration (plugins (list swh-plugins))))
16003 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
16008 @node Database Services
16009 @subsection Database Services
16013 The @code{(gnu services databases)} module provides the following services.
16015 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
16016 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
16017 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
16018 Return a service that runs @var{postgresql}, the PostgreSQL database
16021 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
16022 creates a database cluster with @var{locale} as the default
16023 locale, stored in @var{data-directory}. It then listens on @var{port}.
16025 @cindex postgresql extension-packages
16026 Additional extensions are loaded from packages listed in
16027 @var{extension-packages}. Extensions are available at runtime. For instance,
16028 to create a geographic database using the @code{postgis} extension, a user can
16029 configure the postgresql-service as in this example:
16033 (use-package-modules databases geo)
16037 ;; postgresql is required to run `psql' but postgis is not required for
16038 ;; proper operation.
16039 (packages (cons* postgresql %base-packages))
16042 (postgresql-service #:extension-packages (list postgis))
16046 Then the extension becomes visible and you can initialise an empty geographic
16047 database in this way:
16051 > create database postgistest;
16052 > \connect postgistest;
16053 > create extension postgis;
16054 > create extension postgis_topology;
16057 There is no need to add this field for contrib extensions such as hstore or
16058 dblink as they are already loadable by postgresql. This field is only
16059 required to add extensions provided by other packages.
16062 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
16063 Return a service that runs @command{mysqld}, the MySQL or MariaDB
16066 The optional @var{config} argument specifies the configuration for
16067 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
16070 @deftp {Data Type} mysql-configuration
16071 Data type representing the configuration of @var{mysql-service}.
16074 @item @code{mysql} (default: @var{mariadb})
16075 Package object of the MySQL database server, can be either @var{mariadb}
16078 For MySQL, a temporary root password will be displayed at activation time.
16079 For MariaDB, the root password is empty.
16081 @item @code{port} (default: @code{3306})
16082 TCP port on which the database server listens for incoming connections.
16086 @defvr {Scheme Variable} memcached-service-type
16087 This is the service type for the @uref{https://memcached.org/,
16088 Memcached} service, which provides a distributed in memory cache. The
16089 value for the service type is a @code{memcached-configuration} object.
16093 (service memcached-service-type)
16096 @deftp {Data Type} memcached-configuration
16097 Data type representing the configuration of memcached.
16100 @item @code{memcached} (default: @code{memcached})
16101 The Memcached package to use.
16103 @item @code{interfaces} (default: @code{'("0.0.0.0")})
16104 Network interfaces on which to listen.
16106 @item @code{tcp-port} (default: @code{11211})
16107 Port on which to accept connections on,
16109 @item @code{udp-port} (default: @code{11211})
16110 Port on which to accept UDP connections on, a value of 0 will disable
16111 listening on a UDP socket.
16113 @item @code{additional-options} (default: @code{'()})
16114 Additional command line options to pass to @code{memcached}.
16118 @defvr {Scheme Variable} mongodb-service-type
16119 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
16120 The value for the service type is a @code{mongodb-configuration} object.
16124 (service mongodb-service-type)
16127 @deftp {Data Type} mongodb-configuration
16128 Data type representing the configuration of mongodb.
16131 @item @code{mongodb} (default: @code{mongodb})
16132 The MongoDB package to use.
16134 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
16135 The configuration file for MongoDB.
16137 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16138 This value is used to create the directory, so that it exists and is
16139 owned by the mongodb user. It should match the data-directory which
16140 MongoDB is configured to use through the configuration file.
16144 @defvr {Scheme Variable} redis-service-type
16145 This is the service type for the @uref{https://redis.io/, Redis}
16146 key/value store, whose value is a @code{redis-configuration} object.
16149 @deftp {Data Type} redis-configuration
16150 Data type representing the configuration of redis.
16153 @item @code{redis} (default: @code{redis})
16154 The Redis package to use.
16156 @item @code{bind} (default: @code{"127.0.0.1"})
16157 Network interface on which to listen.
16159 @item @code{port} (default: @code{6379})
16160 Port on which to accept connections on, a value of 0 will disable
16161 listening on a TCP socket.
16163 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16164 Directory in which to store the database and related files.
16168 @node Mail Services
16169 @subsection Mail Services
16173 The @code{(gnu services mail)} module provides Guix service definitions
16174 for email services: IMAP, POP3, and LMTP servers, as well as mail
16175 transport agents (MTAs). Lots of acronyms! These services are detailed
16176 in the subsections below.
16178 @subsubheading Dovecot Service
16180 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16181 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16184 By default, Dovecot does not need much configuration; the default
16185 configuration object created by @code{(dovecot-configuration)} will
16186 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16187 certificate will be generated for TLS-protected connections, though
16188 Dovecot will also listen on cleartext ports by default. There are a
16189 number of options, though, which mail administrators might need to change,
16190 and as is the case with other services, Guix allows the system
16191 administrator to specify these parameters via a uniform Scheme interface.
16193 For example, to specify that mail is located at @code{maildir~/.mail},
16194 one would instantiate the Dovecot service like this:
16197 (dovecot-service #:config
16198 (dovecot-configuration
16199 (mail-location "maildir:~/.mail")))
16202 The available configuration parameters follow. Each parameter
16203 definition is preceded by its type; for example, @samp{string-list foo}
16204 indicates that the @code{foo} parameter should be specified as a list of
16205 strings. There is also a way to specify the configuration as a string,
16206 if you have an old @code{dovecot.conf} file that you want to port over
16207 from some other system; see the end for more details.
16209 @c The following documentation was initially generated by
16210 @c (generate-documentation) in (gnu services mail). Manually maintained
16211 @c documentation is better, so we shouldn't hesitate to edit below as
16212 @c needed. However if the change you want to make to this documentation
16213 @c can be done in an automated way, it's probably easier to change
16214 @c (generate-documentation) than to make it below and have to deal with
16215 @c the churn as dovecot updates.
16217 Available @code{dovecot-configuration} fields are:
16219 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16220 The dovecot package.
16223 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16224 A list of IPs or hosts where to listen for connections. @samp{*}
16225 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16226 interfaces. If you want to specify non-default ports or anything more
16227 complex, customize the address and port fields of the
16228 @samp{inet-listener} of the specific services you are interested in.
16231 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16232 List of protocols we want to serve. Available protocols include
16233 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16235 Available @code{protocol-configuration} fields are:
16237 @deftypevr {@code{protocol-configuration} parameter} string name
16238 The name of the protocol.
16241 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16242 UNIX socket path to the master authentication server to find users.
16243 This is used by imap (for shared users) and lda.
16244 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16247 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16248 Space separated list of plugins to load.
16251 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16252 Maximum number of IMAP connections allowed for a user from each IP
16253 address. NOTE: The username is compared case-sensitively.
16254 Defaults to @samp{10}.
16259 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16260 List of services to enable. Available services include @samp{imap},
16261 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16264 Available @code{service-configuration} fields are:
16266 @deftypevr {@code{service-configuration} parameter} string kind
16267 The service kind. Valid values include @code{director},
16268 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16269 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16270 @code{tcpwrap}, @code{quota-warning}, or anything else.
16273 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16274 Listeners for the service. A listener is either a
16275 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16276 an @code{inet-listener-configuration}.
16277 Defaults to @samp{()}.
16279 Available @code{unix-listener-configuration} fields are:
16281 @deftypevr {@code{unix-listener-configuration} parameter} string path
16282 Path to the file, relative to @code{base-dir} field. This is also used as
16286 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16287 The access mode for the socket.
16288 Defaults to @samp{"0600"}.
16291 @deftypevr {@code{unix-listener-configuration} parameter} string user
16292 The user to own the socket.
16293 Defaults to @samp{""}.
16296 @deftypevr {@code{unix-listener-configuration} parameter} string group
16297 The group to own the socket.
16298 Defaults to @samp{""}.
16302 Available @code{fifo-listener-configuration} fields are:
16304 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16305 Path to the file, relative to @code{base-dir} field. This is also used as
16309 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16310 The access mode for the socket.
16311 Defaults to @samp{"0600"}.
16314 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16315 The user to own the socket.
16316 Defaults to @samp{""}.
16319 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16320 The group to own the socket.
16321 Defaults to @samp{""}.
16325 Available @code{inet-listener-configuration} fields are:
16327 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16328 The protocol to listen for.
16331 @deftypevr {@code{inet-listener-configuration} parameter} string address
16332 The address on which to listen, or empty for all addresses.
16333 Defaults to @samp{""}.
16336 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16337 The port on which to listen.
16340 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16341 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16343 Defaults to @samp{#t}.
16348 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16349 Maximum number of simultaneous client connections per process. Once
16350 this number of connections is received, the next incoming connection
16351 will prompt Dovecot to spawn another process. If set to 0,
16352 @code{default-client-limit} is used instead.
16354 Defaults to @samp{0}.
16358 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16359 Number of connections to handle before starting a new process.
16360 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16361 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16362 Defaults to @samp{1}.
16366 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16367 Maximum number of processes that can exist for this service. If set to
16368 0, @code{default-process-limit} is used instead.
16370 Defaults to @samp{0}.
16374 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16375 Number of processes to always keep waiting for more connections.
16376 Defaults to @samp{0}.
16379 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16380 If you set @samp{service-count 0}, you probably need to grow
16382 Defaults to @samp{256000000}.
16387 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16388 Dict configuration, as created by the @code{dict-configuration}
16391 Available @code{dict-configuration} fields are:
16393 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16394 A list of key-value pairs that this dict should hold.
16395 Defaults to @samp{()}.
16400 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16401 A list of passdb configurations, each one created by the
16402 @code{passdb-configuration} constructor.
16404 Available @code{passdb-configuration} fields are:
16406 @deftypevr {@code{passdb-configuration} parameter} string driver
16407 The driver that the passdb should use. Valid values include
16408 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16410 Defaults to @samp{"pam"}.
16413 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16414 Space separated list of arguments to the passdb driver.
16415 Defaults to @samp{""}.
16420 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16421 List of userdb configurations, each one created by the
16422 @code{userdb-configuration} constructor.
16424 Available @code{userdb-configuration} fields are:
16426 @deftypevr {@code{userdb-configuration} parameter} string driver
16427 The driver that the userdb should use. Valid values include
16428 @samp{passwd} and @samp{static}.
16429 Defaults to @samp{"passwd"}.
16432 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16433 Space separated list of arguments to the userdb driver.
16434 Defaults to @samp{""}.
16437 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16438 Override fields from passwd.
16439 Defaults to @samp{()}.
16444 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16445 Plug-in configuration, created by the @code{plugin-configuration}
16449 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16450 List of namespaces. Each item in the list is created by the
16451 @code{namespace-configuration} constructor.
16453 Available @code{namespace-configuration} fields are:
16455 @deftypevr {@code{namespace-configuration} parameter} string name
16456 Name for this namespace.
16459 @deftypevr {@code{namespace-configuration} parameter} string type
16460 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16461 Defaults to @samp{"private"}.
16464 @deftypevr {@code{namespace-configuration} parameter} string separator
16465 Hierarchy separator to use. You should use the same separator for
16466 all namespaces or some clients get confused. @samp{/} is usually a good
16467 one. The default however depends on the underlying mail storage
16469 Defaults to @samp{""}.
16472 @deftypevr {@code{namespace-configuration} parameter} string prefix
16473 Prefix required to access this namespace. This needs to be
16474 different for all namespaces. For example @samp{Public/}.
16475 Defaults to @samp{""}.
16478 @deftypevr {@code{namespace-configuration} parameter} string location
16479 Physical location of the mailbox. This is in the same format as
16480 mail_location, which is also the default for it.
16481 Defaults to @samp{""}.
16484 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16485 There can be only one INBOX, and this setting defines which
16487 Defaults to @samp{#f}.
16490 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16491 If namespace is hidden, it's not advertised to clients via NAMESPACE
16492 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16493 useful when converting from another server with different namespaces
16494 which you want to deprecate but still keep working. For example you can
16495 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16497 Defaults to @samp{#f}.
16500 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16501 Show the mailboxes under this namespace with the LIST command. This
16502 makes the namespace visible for clients that do not support the NAMESPACE
16503 extension. The special @code{children} value lists child mailboxes, but
16504 hides the namespace prefix.
16505 Defaults to @samp{#t}.
16508 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16509 Namespace handles its own subscriptions. If set to @code{#f}, the
16510 parent namespace handles them. The empty prefix should always have this
16512 Defaults to @samp{#t}.
16515 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16516 List of predefined mailboxes in this namespace.
16517 Defaults to @samp{()}.
16519 Available @code{mailbox-configuration} fields are:
16521 @deftypevr {@code{mailbox-configuration} parameter} string name
16522 Name for this mailbox.
16525 @deftypevr {@code{mailbox-configuration} parameter} string auto
16526 @samp{create} will automatically create this mailbox.
16527 @samp{subscribe} will both create and subscribe to the mailbox.
16528 Defaults to @samp{"no"}.
16531 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16532 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16533 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16534 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16535 Defaults to @samp{()}.
16542 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16543 Base directory where to store runtime data.
16544 Defaults to @samp{"/var/run/dovecot/"}.
16547 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16548 Greeting message for clients.
16549 Defaults to @samp{"Dovecot ready."}.
16552 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16553 List of trusted network ranges. Connections from these IPs are
16554 allowed to override their IP addresses and ports (for logging and for
16555 authentication checks). @samp{disable-plaintext-auth} is also ignored
16556 for these networks. Typically you would specify your IMAP proxy servers
16558 Defaults to @samp{()}.
16561 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16562 List of login access check sockets (e.g.@: tcpwrap).
16563 Defaults to @samp{()}.
16566 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16567 Show more verbose process titles (in ps). Currently shows user name
16568 and IP address. Useful for seeing who is actually using the IMAP
16569 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16571 Defaults to @samp{#f}.
16574 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
16575 Should all processes be killed when Dovecot master process shuts down.
16576 Setting this to @code{#f} means that Dovecot can be upgraded without
16577 forcing existing client connections to close (although that could also
16578 be a problem if the upgrade is e.g.@: due to a security fix).
16579 Defaults to @samp{#t}.
16582 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
16583 If non-zero, run mail commands via this many connections to doveadm
16584 server, instead of running them directly in the same process.
16585 Defaults to @samp{0}.
16588 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
16589 UNIX socket or host:port used for connecting to doveadm server.
16590 Defaults to @samp{"doveadm-server"}.
16593 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
16594 List of environment variables that are preserved on Dovecot startup
16595 and passed down to all of its child processes. You can also give
16596 key=value pairs to always set specific settings.
16599 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
16600 Disable LOGIN command and all other plaintext authentications unless
16601 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
16602 matches the local IP (i.e.@: you're connecting from the same computer),
16603 the connection is considered secure and plaintext authentication is
16604 allowed. See also ssl=required setting.
16605 Defaults to @samp{#t}.
16608 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
16609 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
16610 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
16611 for caching to be used.
16612 Defaults to @samp{0}.
16615 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
16616 Time to live for cached data. After TTL expires the cached record
16617 is no longer used, *except* if the main database lookup returns internal
16618 failure. We also try to handle password changes automatically: If
16619 user's previous authentication was successful, but this one wasn't, the
16620 cache isn't used. For now this works only with plaintext
16622 Defaults to @samp{"1 hour"}.
16625 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
16626 TTL for negative hits (user not found, password mismatch).
16627 0 disables caching them completely.
16628 Defaults to @samp{"1 hour"}.
16631 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
16632 List of realms for SASL authentication mechanisms that need them.
16633 You can leave it empty if you don't want to support multiple realms.
16634 Many clients simply use the first one listed here, so keep the default
16636 Defaults to @samp{()}.
16639 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
16640 Default realm/domain to use if none was specified. This is used for
16641 both SASL realms and appending @@domain to username in plaintext
16643 Defaults to @samp{""}.
16646 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
16647 List of allowed characters in username. If the user-given username
16648 contains a character not listed in here, the login automatically fails.
16649 This is just an extra check to make sure user can't exploit any
16650 potential quote escaping vulnerabilities with SQL/LDAP databases. If
16651 you want to allow all characters, set this value to empty.
16652 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
16655 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
16656 Username character translations before it's looked up from
16657 databases. The value contains series of from -> to characters. For
16658 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
16659 translated to @samp{@@}.
16660 Defaults to @samp{""}.
16663 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
16664 Username formatting before it's looked up from databases. You can
16665 use the standard variables here, e.g.@: %Lu would lowercase the username,
16666 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
16667 change the @samp{@@} into @samp{-AT-}. This translation is done after
16668 @samp{auth-username-translation} changes.
16669 Defaults to @samp{"%Lu"}.
16672 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
16673 If you want to allow master users to log in by specifying the master
16674 username within the normal username string (i.e.@: not using SASL
16675 mechanism's support for it), you can specify the separator character
16676 here. The format is then <username><separator><master username>.
16677 UW-IMAP uses @samp{*} as the separator, so that could be a good
16679 Defaults to @samp{""}.
16682 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
16683 Username to use for users logging in with ANONYMOUS SASL
16685 Defaults to @samp{"anonymous"}.
16688 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
16689 Maximum number of dovecot-auth worker processes. They're used to
16690 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
16691 They're automatically created and destroyed as needed.
16692 Defaults to @samp{30}.
16695 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
16696 Host name to use in GSSAPI principal names. The default is to use
16697 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
16698 allow all keytab entries.
16699 Defaults to @samp{""}.
16702 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16703 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16704 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16705 need to change the auth service to run as root to be able to read this
16707 Defaults to @samp{""}.
16710 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16711 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16712 and @samp{ntlm-auth} helper.
16713 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16714 Defaults to @samp{#f}.
16717 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16718 Path for Samba's @samp{ntlm-auth} helper binary.
16719 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16722 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16723 Time to delay before replying to failed authentications.
16724 Defaults to @samp{"2 secs"}.
16727 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16728 Require a valid SSL client certificate or the authentication
16730 Defaults to @samp{#f}.
16733 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16734 Take the username from client's SSL certificate, using
16735 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16737 Defaults to @samp{#f}.
16740 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16741 List of wanted authentication mechanisms. Supported mechanisms are:
16742 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16743 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16744 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16745 @samp{disable-plaintext-auth} setting.
16748 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16749 List of IPs or hostnames to all director servers, including ourself.
16750 Ports can be specified as ip:port. The default port is the same as what
16751 director service's @samp{inet-listener} is using.
16752 Defaults to @samp{()}.
16755 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16756 List of IPs or hostnames to all backend mail servers. Ranges are
16757 allowed too, like 10.0.0.10-10.0.0.30.
16758 Defaults to @samp{()}.
16761 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16762 How long to redirect users to a specific server after it no longer
16763 has any connections.
16764 Defaults to @samp{"15 min"}.
16767 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16768 How the username is translated before being hashed. Useful values
16769 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16770 are shared within domain.
16771 Defaults to @samp{"%Lu"}.
16774 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16775 Log file to use for error messages. @samp{syslog} logs to syslog,
16776 @samp{/dev/stderr} logs to stderr.
16777 Defaults to @samp{"syslog"}.
16780 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16781 Log file to use for informational messages. Defaults to
16783 Defaults to @samp{""}.
16786 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16787 Log file to use for debug messages. Defaults to
16788 @samp{info-log-path}.
16789 Defaults to @samp{""}.
16792 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16793 Syslog facility to use if you're logging to syslog. Usually if you
16794 don't want to use @samp{mail}, you'll use local0..local7. Also other
16795 standard facilities are supported.
16796 Defaults to @samp{"mail"}.
16799 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16800 Log unsuccessful authentication attempts and the reasons why they
16802 Defaults to @samp{#f}.
16805 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16806 In case of password mismatches, log the attempted password. Valid
16807 values are no, plain and sha1. sha1 can be useful for detecting brute
16808 force password attempts vs. user simply trying the same password over
16809 and over again. You can also truncate the value to n chars by appending
16810 ":n" (e.g.@: sha1:6).
16811 Defaults to @samp{"no"}.
16814 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16815 Even more verbose logging for debugging purposes. Shows for example
16817 Defaults to @samp{#f}.
16820 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16821 In case of password mismatches, log the passwords and used scheme so
16822 the problem can be debugged. Enabling this also enables
16824 Defaults to @samp{#f}.
16827 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16828 Enable mail process debugging. This can help you figure out why
16829 Dovecot isn't finding your mails.
16830 Defaults to @samp{#f}.
16833 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16834 Show protocol level SSL errors.
16835 Defaults to @samp{#f}.
16838 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16839 Prefix for each line written to log file. % codes are in
16840 strftime(3) format.
16841 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16844 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16845 List of elements we want to log. The elements which have a
16846 non-empty variable value are joined together to form a comma-separated
16850 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16851 Login log format. %s contains @samp{login-log-format-elements}
16852 string, %$ contains the data we want to log.
16853 Defaults to @samp{"%$: %s"}.
16856 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16857 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16858 of possible variables you can use.
16859 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16862 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16863 Format to use for logging mail deliveries. You can use variables:
16866 Delivery status message (e.g.@: @samp{saved to INBOX})
16878 Defaults to @samp{"msgid=%m: %$"}.
16881 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16882 Location for users' mailboxes. The default is empty, which means
16883 that Dovecot tries to find the mailboxes automatically. This won't work
16884 if the user doesn't yet have any mail, so you should explicitly tell
16885 Dovecot the full location.
16887 If you're using mbox, giving a path to the INBOX
16888 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16889 where the other mailboxes are kept. This is called the "root mail
16890 directory", and it must be the first path given in the
16891 @samp{mail-location} setting.
16893 There are a few special variables you can use, eg.:
16899 user part in user@@domain, same as %u if there's no domain
16901 domain part in user@@domain, empty if there's no domain
16906 See doc/wiki/Variables.txt for full list. Some examples:
16908 @item maildir:~/Maildir
16909 @item mbox:~/mail:INBOX=/var/mail/%u
16910 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16912 Defaults to @samp{""}.
16915 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16916 System user and group used to access mails. If you use multiple,
16917 userdb can override these by returning uid or gid fields. You can use
16918 either numbers or names. <doc/wiki/UserIds.txt>.
16919 Defaults to @samp{""}.
16922 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16924 Defaults to @samp{""}.
16927 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16928 Group to enable temporarily for privileged operations. Currently
16929 this is used only with INBOX when either its initial creation or
16930 dotlocking fails. Typically this is set to "mail" to give access to
16932 Defaults to @samp{""}.
16935 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16936 Grant access to these supplementary groups for mail processes.
16937 Typically these are used to set up access to shared mailboxes. Note
16938 that it may be dangerous to set these if users can create
16939 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16940 could allow a user to delete others' mailboxes, or ln -s
16941 /secret/shared/box ~/mail/mybox would allow reading it).
16942 Defaults to @samp{""}.
16945 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16946 Allow full file system access to clients. There's no access checks
16947 other than what the operating system does for the active UID/GID. It
16948 works with both maildir and mboxes, allowing you to prefix mailboxes
16949 names with e.g.@: /path/ or ~user/.
16950 Defaults to @samp{#f}.
16953 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16954 Don't use mmap() at all. This is required if you store indexes to
16955 shared file systems (NFS or clustered file system).
16956 Defaults to @samp{#f}.
16959 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16960 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16961 supports @samp{O_EXCL} since version 3, so this should be safe to use
16962 nowadays by default.
16963 Defaults to @samp{#t}.
16966 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16967 When to use fsync() or fdatasync() calls:
16970 Whenever necessary to avoid losing important data
16972 Useful with e.g.@: NFS when write()s are delayed
16974 Never use it (best performance, but crashes can lose data).
16976 Defaults to @samp{"optimized"}.
16979 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16980 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16981 NFS caches whenever needed. If you're using only a single mail server
16983 Defaults to @samp{#f}.
16986 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16987 Mail index files also exist in NFS. Setting this to yes requires
16988 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16989 Defaults to @samp{#f}.
16992 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16993 Locking method for index files. Alternatives are fcntl, flock and
16994 dotlock. Dotlocking uses some tricks which may create more disk I/O
16995 than other locking methods. NFS users: flock doesn't work, remember to
16996 change @samp{mmap-disable}.
16997 Defaults to @samp{"fcntl"}.
17000 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
17001 Directory in which LDA/LMTP temporarily stores incoming mails >128
17003 Defaults to @samp{"/tmp"}.
17006 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
17007 Valid UID range for users. This is mostly to make sure that users can't
17008 log in as daemons or other system users. Note that denying root logins is
17009 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
17011 Defaults to @samp{500}.
17014 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
17016 Defaults to @samp{0}.
17019 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
17020 Valid GID range for users. Users having non-valid GID as primary group ID
17021 aren't allowed to log in. If user belongs to supplementary groups with
17022 non-valid GIDs, those groups are not set.
17023 Defaults to @samp{1}.
17026 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
17028 Defaults to @samp{0}.
17031 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
17032 Maximum allowed length for mail keyword name. It's only forced when
17033 trying to create new keywords.
17034 Defaults to @samp{50}.
17037 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
17038 List of directories under which chrooting is allowed for mail
17039 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
17040 too). This setting doesn't affect @samp{login-chroot}
17041 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
17042 "/./" in home dirs are ignored. WARNING: Never add directories here
17043 which local users can modify, that may lead to root exploit. Usually
17044 this should be done only if you don't allow shell access for users.
17045 <doc/wiki/Chrooting.txt>.
17046 Defaults to @samp{()}.
17049 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
17050 Default chroot directory for mail processes. This can be overridden
17051 for specific users in user database by giving /./ in user's home
17052 directory (e.g.@: /home/./user chroots into /home). Note that usually
17053 there is no real need to do chrooting, Dovecot doesn't allow users to
17054 access files outside their mail directory anyway. If your home
17055 directories are prefixed with the chroot directory, append "/."@: to
17056 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
17057 Defaults to @samp{""}.
17060 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
17061 UNIX socket path to master authentication server to find users.
17062 This is used by imap (for shared users) and lda.
17063 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17066 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
17067 Directory where to look up mail plugins.
17068 Defaults to @samp{"/usr/lib/dovecot"}.
17071 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
17072 List of plugins to load for all services. Plugins specific to IMAP,
17073 LDA, etc.@: are added to this list in their own .conf files.
17074 Defaults to @samp{()}.
17077 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
17078 The minimum number of mails in a mailbox before updates are done to
17079 cache file. This allows optimizing Dovecot's behavior to do less disk
17080 writes at the cost of more disk reads.
17081 Defaults to @samp{0}.
17084 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
17085 When IDLE command is running, mailbox is checked once in a while to
17086 see if there are any new mails or other changes. This setting defines
17087 the minimum time to wait between those checks. Dovecot can also use
17088 dnotify, inotify and kqueue to find out immediately when changes
17090 Defaults to @samp{"30 secs"}.
17093 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
17094 Save mails with CR+LF instead of plain LF. This makes sending those
17095 mails take less CPU, especially with sendfile() syscall with Linux and
17096 FreeBSD. But it also creates a bit more disk I/O which may just make it
17097 slower. Also note that if other software reads the mboxes/maildirs,
17098 they may handle the extra CRs wrong and cause problems.
17099 Defaults to @samp{#f}.
17102 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
17103 By default LIST command returns all entries in maildir beginning
17104 with a dot. Enabling this option makes Dovecot return only entries
17105 which are directories. This is done by stat()ing each entry, so it
17106 causes more disk I/O.
17107 (For systems setting struct @samp{dirent->d_type} this check is free
17108 and it's done always regardless of this setting).
17109 Defaults to @samp{#f}.
17112 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
17113 When copying a message, do it with hard links whenever possible.
17114 This makes the performance much better, and it's unlikely to have any
17116 Defaults to @samp{#t}.
17119 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
17120 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
17121 directory only when its mtime changes unexpectedly or when we can't find
17122 the mail otherwise.
17123 Defaults to @samp{#f}.
17126 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
17127 Which locking methods to use for locking mbox. There are four
17132 Create <mailbox>.lock file. This is the oldest and most NFS-safe
17133 solution. If you want to use /var/mail/ like directory, the users will
17134 need write access to that directory.
17136 Same as dotlock, but if it fails because of permissions or because there
17137 isn't enough disk space, just skip it.
17139 Use this if possible. Works with NFS too if lockd is used.
17141 May not exist in all systems. Doesn't work with NFS.
17143 May not exist in all systems. Doesn't work with NFS.
17146 You can use multiple locking methods; if you do the order they're declared
17147 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17148 locking methods as well. Some operating systems don't allow using some of
17149 them simultaneously.
17152 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17156 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17157 Maximum time to wait for lock (all of them) before aborting.
17158 Defaults to @samp{"5 mins"}.
17161 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17162 If dotlock exists but the mailbox isn't modified in any way,
17163 override the lock file after this much time.
17164 Defaults to @samp{"2 mins"}.
17167 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17168 When mbox changes unexpectedly we have to fully read it to find out
17169 what changed. If the mbox is large this can take a long time. Since
17170 the change is usually just a newly appended mail, it'd be faster to
17171 simply read the new mails. If this setting is enabled, Dovecot does
17172 this but still safely fallbacks to re-reading the whole mbox file
17173 whenever something in mbox isn't how it's expected to be. The only real
17174 downside to this setting is that if some other MUA changes message
17175 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17176 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17177 Defaults to @samp{#t}.
17180 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17181 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17182 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17183 @samp{mbox-dirty-syncs} is ignored.
17184 Defaults to @samp{#f}.
17187 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17188 Delay writing mbox headers until doing a full write sync (EXPUNGE
17189 and CHECK commands and when closing the mailbox). This is especially
17190 useful for POP3 where clients often delete all mails. The downside is
17191 that our changes aren't immediately visible to other MUAs.
17192 Defaults to @samp{#t}.
17195 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17196 If mbox size is smaller than this (e.g.@: 100k), don't write index
17197 files. If an index file already exists it's still read, just not
17199 Defaults to @samp{0}.
17202 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17203 Maximum dbox file size until it's rotated.
17204 Defaults to @samp{10000000}.
17207 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17208 Maximum dbox file age until it's rotated. Typically in days. Day
17209 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17211 Defaults to @samp{"1d"}.
17214 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17215 When creating new mdbox files, immediately preallocate their size to
17216 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17217 with some file systems (ext4, xfs).
17218 Defaults to @samp{#f}.
17221 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17222 sdbox and mdbox support saving mail attachments to external files,
17223 which also allows single instance storage for them. Other backends
17224 don't support this for now.
17226 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17228 Directory root where to store mail attachments. Disabled, if empty.
17229 Defaults to @samp{""}.
17232 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17233 Attachments smaller than this aren't saved externally. It's also
17234 possible to write a plugin to disable saving specific attachments
17236 Defaults to @samp{128000}.
17239 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17240 File system backend to use for saving attachments:
17243 No SiS done by Dovecot (but this might help FS's own deduplication)
17245 SiS with immediate byte-by-byte comparison during saving
17246 @item sis-queue posix
17247 SiS with delayed comparison and deduplication.
17249 Defaults to @samp{"sis posix"}.
17252 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17253 Hash format to use in attachment filenames. You can add any text and
17254 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17255 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17256 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17257 Defaults to @samp{"%@{sha1@}"}.
17260 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17262 Defaults to @samp{100}.
17265 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17267 Defaults to @samp{1000}.
17270 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17271 Default VSZ (virtual memory size) limit for service processes.
17272 This is mainly intended to catch and kill processes that leak memory
17273 before they eat up everything.
17274 Defaults to @samp{256000000}.
17277 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17278 Login user is internally used by login processes. This is the most
17279 untrusted user in Dovecot system. It shouldn't have access to anything
17281 Defaults to @samp{"dovenull"}.
17284 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17285 Internal user is used by unprivileged processes. It should be
17286 separate from login user, so that login processes can't disturb other
17288 Defaults to @samp{"dovecot"}.
17291 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17292 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17293 Defaults to @samp{"required"}.
17296 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17297 PEM encoded X.509 SSL/TLS certificate (public key).
17298 Defaults to @samp{"</etc/dovecot/default.pem"}.
17301 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17302 PEM encoded SSL/TLS private key. The key is opened before
17303 dropping root privileges, so keep the key file unreadable by anyone but
17305 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17308 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17309 If key file is password protected, give the password here.
17310 Alternatively give it when starting dovecot with -p parameter. Since
17311 this file is often world-readable, you may want to place this setting
17312 instead to a different.
17313 Defaults to @samp{""}.
17316 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17317 PEM encoded trusted certificate authority. Set this only if you
17318 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17319 contain the CA certificate(s) followed by the matching
17320 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17321 Defaults to @samp{""}.
17324 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17325 Require that CRL check succeeds for client certificates.
17326 Defaults to @samp{#t}.
17329 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17330 Request client to send a certificate. If you also want to require
17331 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17332 Defaults to @samp{#f}.
17335 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17336 Which field from certificate to use for username. commonName and
17337 x500UniqueIdentifier are the usual choices. You'll also need to set
17338 @samp{auth-ssl-username-from-cert? #t}.
17339 Defaults to @samp{"commonName"}.
17342 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17343 Minimum SSL protocol version to accept.
17344 Defaults to @samp{"TLSv1"}.
17347 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17348 SSL ciphers to use.
17349 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17352 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17353 SSL crypto device to use, for valid values run "openssl engine".
17354 Defaults to @samp{""}.
17357 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17358 Address to use when sending rejection mails.
17359 %d expands to recipient domain.
17360 Defaults to @samp{"postmaster@@%d"}.
17363 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17364 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17365 and in LMTP replies. Default is the system's real hostname@@domain.
17366 Defaults to @samp{""}.
17369 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17370 If user is over quota, return with temporary failure instead of
17372 Defaults to @samp{#f}.
17375 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17376 Binary to use for sending mails.
17377 Defaults to @samp{"/usr/sbin/sendmail"}.
17380 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17381 If non-empty, send mails via this SMTP host[:port] instead of
17383 Defaults to @samp{""}.
17386 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17387 Subject: header to use for rejection mails. You can use the same
17388 variables as for @samp{rejection-reason} below.
17389 Defaults to @samp{"Rejected: %s"}.
17392 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17393 Human readable error message for rejection mails. You can use
17406 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17409 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17410 Delimiter character between local-part and detail in email
17412 Defaults to @samp{"+"}.
17415 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17416 Header where the original recipient address (SMTP's RCPT TO:
17417 address) is taken from if not available elsewhere. With dovecot-lda -a
17418 parameter overrides this. A commonly used header for this is
17420 Defaults to @samp{""}.
17423 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17424 Should saving a mail to a nonexistent mailbox automatically create
17426 Defaults to @samp{#f}.
17429 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17430 Should automatically created mailboxes be also automatically
17432 Defaults to @samp{#f}.
17435 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17436 Maximum IMAP command line length. Some clients generate very long
17437 command lines with huge mailboxes, so you may need to raise this if you
17438 get "Too long argument" or "IMAP command line too large" errors
17440 Defaults to @samp{64000}.
17443 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17444 IMAP logout format string:
17447 total number of bytes read from client
17449 total number of bytes sent to client.
17451 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17452 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@}"}.
17455 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17456 Override the IMAP CAPABILITY response. If the value begins with '+',
17457 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17458 Defaults to @samp{""}.
17461 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17462 How long to wait between "OK Still here" notifications when client
17464 Defaults to @samp{"2 mins"}.
17467 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17468 ID field names and values to send to clients. Using * as the value
17469 makes Dovecot use the default value. The following fields have default
17470 values currently: name, version, os, os-version, support-url,
17472 Defaults to @samp{""}.
17475 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17476 ID fields sent by client to log. * means everything.
17477 Defaults to @samp{""}.
17480 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17481 Workarounds for various client bugs:
17484 @item delay-newmail
17485 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17486 CHECK commands. Some clients ignore them otherwise, for example OSX
17487 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17488 may show user "Message no longer in server" errors. Note that OE6
17489 still breaks even with this workaround if synchronization is set to
17492 @item tb-extra-mailbox-sep
17493 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17494 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17495 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17497 @item tb-lsub-flags
17498 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17499 This makes Thunderbird realize they aren't selectable and show them
17500 greyed out, instead of only later giving "not selectable" popup error.
17502 Defaults to @samp{()}.
17505 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17506 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17507 Defaults to @samp{""}.
17511 Whew! Lots of configuration options. The nice thing about it though is
17512 that Guix has a complete interface to Dovecot's configuration
17513 language. This allows not only a nice way to declare configurations,
17514 but also offers reflective capabilities as well: users can write code to
17515 inspect and transform configurations from within Scheme.
17517 However, it could be that you just want to get a @code{dovecot.conf} up
17518 and running. In that case, you can pass an
17519 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17520 @code{dovecot-service}. As its name indicates, an opaque configuration
17521 does not have easy reflective capabilities.
17523 Available @code{opaque-dovecot-configuration} fields are:
17525 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17526 The dovecot package.
17529 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17530 The contents of the @code{dovecot.conf}, as a string.
17533 For example, if your @code{dovecot.conf} is just the empty string, you
17534 could instantiate a dovecot service like this:
17537 (dovecot-service #:config
17538 (opaque-dovecot-configuration
17542 @subsubheading OpenSMTPD Service
17544 @deffn {Scheme Variable} opensmtpd-service-type
17545 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17546 service, whose value should be an @code{opensmtpd-configuration} object
17547 as in this example:
17550 (service opensmtpd-service-type
17551 (opensmtpd-configuration
17552 (config-file (local-file "./my-smtpd.conf"))))
17556 @deftp {Data Type} opensmtpd-configuration
17557 Data type representing the configuration of opensmtpd.
17560 @item @code{package} (default: @var{opensmtpd})
17561 Package object of the OpenSMTPD SMTP server.
17563 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17564 File-like object of the OpenSMTPD configuration file to use. By default
17565 it listens on the loopback network interface, and allows for mail from
17566 users and daemons on the local machine, as well as permitting email to
17567 remote servers. Run @command{man smtpd.conf} for more information.
17572 @subsubheading Exim Service
17574 @cindex mail transfer agent (MTA)
17575 @cindex MTA (mail transfer agent)
17578 @deffn {Scheme Variable} exim-service-type
17579 This is the type of the @uref{https://exim.org, Exim} mail transfer
17580 agent (MTA), whose value should be an @code{exim-configuration} object
17581 as in this example:
17584 (service exim-service-type
17585 (exim-configuration
17586 (config-file (local-file "./my-exim.conf"))))
17590 In order to use an @code{exim-service-type} service you must also have a
17591 @code{mail-aliases-service-type} service present in your
17592 @code{operating-system} (even if it has no aliases).
17594 @deftp {Data Type} exim-configuration
17595 Data type representing the configuration of exim.
17598 @item @code{package} (default: @var{exim})
17599 Package object of the Exim server.
17601 @item @code{config-file} (default: @code{#f})
17602 File-like object of the Exim configuration file to use. If its value is
17603 @code{#f} then use the default configuration file from the package
17604 provided in @code{package}. The resulting configuration file is loaded
17605 after setting the @code{exim_user} and @code{exim_group} configuration
17611 @subsubheading Getmail service
17616 @deffn {Scheme Variable} getmail-service-type
17617 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
17618 mail retriever, whose value should be an @code{getmail-configuration}.
17621 Available @code{getmail-configuration} fields are:
17623 @deftypevr {@code{getmail-configuration} parameter} symbol name
17624 A symbol to identify the getmail service.
17626 Defaults to @samp{"unset"}.
17630 @deftypevr {@code{getmail-configuration} parameter} package package
17631 The getmail package to use.
17635 @deftypevr {@code{getmail-configuration} parameter} string user
17636 The user to run getmail as.
17638 Defaults to @samp{"getmail"}.
17642 @deftypevr {@code{getmail-configuration} parameter} string group
17643 The group to run getmail as.
17645 Defaults to @samp{"getmail"}.
17649 @deftypevr {@code{getmail-configuration} parameter} string directory
17650 The getmail directory to use.
17652 Defaults to @samp{"/var/lib/getmail/default"}.
17656 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
17657 The getmail configuration file to use.
17659 Available @code{getmail-configuration-file} fields are:
17661 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
17662 What mail account to retrieve mail from, and how to access that account.
17664 Available @code{getmail-retriever-configuration} fields are:
17666 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
17667 The type of mail retriever to use. Valid values include @samp{passwd}
17670 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
17674 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
17675 Space separated list of arguments to the userdb driver.
17677 Defaults to @samp{unset}.
17681 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
17682 Space separated list of arguments to the userdb driver.
17684 Defaults to @samp{unset}.
17688 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
17689 Space separated list of arguments to the userdb driver.
17691 Defaults to @samp{#f}.
17695 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
17696 Override fields from passwd.
17698 Defaults to @samp{""}.
17702 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17703 Override fields from passwd.
17705 Defaults to @samp{()}.
17709 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17710 PEM-formatted key file to use for the TLS negotiation
17712 Defaults to @samp{""}.
17716 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17717 PEM-formatted certificate file to use for the TLS negotiation
17719 Defaults to @samp{""}.
17723 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17724 CA certificates to use
17726 Defaults to @samp{""}.
17730 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17731 Extra retriever parameters
17733 Defaults to @samp{()}.
17739 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17740 What to do with retrieved messages.
17742 Available @code{getmail-destination-configuration} fields are:
17744 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17745 The type of mail destination. Valid values include @samp{Maildir},
17746 @samp{Mboxrd} and @samp{MDA_external}.
17748 Defaults to @samp{unset}.
17752 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17753 The path option for the mail destination. The behaviour depends on the
17756 Defaults to @samp{""}.
17760 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17761 Extra destination parameters
17763 Defaults to @samp{()}.
17769 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17772 Available @code{getmail-options-configuration} fields are:
17774 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17775 If set to @samp{0}, getmail will only print warnings and errors. A
17776 value of @samp{1} means that messages will be printed about retrieving
17777 and deleting messages. If set to @samp{2}, getmail will print messages
17778 about each of it's actions.
17780 Defaults to @samp{1}.
17784 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17785 If true, getmail will retrieve all available messages. Otherwise it
17786 will only retrieve messages it hasn't seen previously.
17788 Defaults to @samp{#t}.
17792 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17793 If set to true, messages will be deleted from the server after
17794 retrieving and successfully delivering them. Otherwise, messages will
17795 be left on the server.
17797 Defaults to @samp{#f}.
17801 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17802 Getmail will delete messages this number of days after seeing them, if
17803 they have been delivered. This means messages will be left on the
17804 server this number of days after delivering them. A value of @samp{0}
17805 disabled this feature.
17807 Defaults to @samp{0}.
17811 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17812 Delete messages larger than this of bytes after retrieving them, even if
17813 the delete and delete-after options are disabled. A value of @samp{0}
17814 disables this feature.
17816 Defaults to @samp{0}.
17820 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17821 Retrieve messages totalling up to this number of bytes before closing
17822 the session with the server. A value of @samp{0} disables this feature.
17824 Defaults to @samp{0}.
17828 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17829 Don't retrieve messages larger than this number of bytes. A value of
17830 @samp{0} disables this feature.
17832 Defaults to @samp{0}.
17836 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17837 If true, getmail will add a Delivered-To header to messages.
17839 Defaults to @samp{#t}.
17843 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17844 If set, getmail adds a Received header to the messages.
17846 Defaults to @samp{#t}.
17850 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17851 Getmail will record a log of its actions to the named file. A value of
17852 @samp{""} disables this feature.
17854 Defaults to @samp{""}.
17858 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17859 If true, getmail will record a log of its actions using the system
17862 Defaults to @samp{#t}.
17866 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17867 If true, getmail will log information about messages not retrieved and
17868 the reason for not retrieving them, as well as starting and ending
17871 Defaults to @samp{#t}.
17875 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17876 Extra options to include.
17878 Defaults to @samp{()}.
17886 @deftypevr {@code{getmail-configuration} parameter} list idle
17887 A list of mailboxes that getmail should wait on the server for new mail
17888 notifications. This depends on the server supporting the IDLE
17891 Defaults to @samp{()}.
17895 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17896 Environment variables to set for getmail.
17898 Defaults to @samp{()}.
17902 @subsubheading Mail Aliases Service
17904 @cindex email aliases
17905 @cindex aliases, for email addresses
17907 @deffn {Scheme Variable} mail-aliases-service-type
17908 This is the type of the service which provides @code{/etc/aliases},
17909 specifying how to deliver mail to users on this system.
17912 (service mail-aliases-service-type
17913 '(("postmaster" "bob")
17914 ("bob" "bob@@example.com" "bob@@example2.com")))
17918 The configuration for a @code{mail-aliases-service-type} service is an
17919 association list denoting how to deliver mail that comes to this
17920 system. Each entry is of the form @code{(alias addresses ...)}, with
17921 @code{alias} specifying the local alias and @code{addresses} specifying
17922 where to deliver this user's mail.
17924 The aliases aren't required to exist as users on the local system. In
17925 the above example, there doesn't need to be a @code{postmaster} entry in
17926 the @code{operating-system}'s @code{user-accounts} in order to deliver
17927 the @code{postmaster} mail to @code{bob} (which subsequently would
17928 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17930 @subsubheading GNU Mailutils IMAP4 Daemon
17931 @cindex GNU Mailutils IMAP4 Daemon
17933 @deffn {Scheme Variable} imap4d-service-type
17934 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17935 mailutils, GNU Mailutils Manual}), whose value should be an
17936 @code{imap4d-configuration} object as in this example:
17939 (service imap4d-service-type
17940 (imap4d-configuration
17941 (config-file (local-file "imap4d.conf"))))
17945 @deftp {Data Type} imap4d-configuration
17946 Data type representing the configuration of @command{imap4d}.
17949 @item @code{package} (default: @code{mailutils})
17950 The package that provides @command{imap4d}.
17952 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17953 File-like object of the configuration file to use, by default it will listen
17954 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17955 Mailutils Manual}, for details.
17960 @node Messaging Services
17961 @subsection Messaging Services
17966 The @code{(gnu services messaging)} module provides Guix service
17967 definitions for messaging services: currently only Prosody is supported.
17969 @subsubheading Prosody Service
17971 @deffn {Scheme Variable} prosody-service-type
17972 This is the type for the @uref{https://prosody.im, Prosody XMPP
17973 communication server}. Its value must be a @code{prosody-configuration}
17974 record as in this example:
17977 (service prosody-service-type
17978 (prosody-configuration
17979 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17982 (int-component-configuration
17983 (hostname "conference.example.net")
17985 (mod-muc (mod-muc-configuration)))))
17988 (virtualhost-configuration
17989 (domain "example.net"))))))
17992 See below for details about @code{prosody-configuration}.
17996 By default, Prosody does not need much configuration. Only one
17997 @code{virtualhosts} field is needed: it specifies the domain you wish
18000 You can perform various sanity checks on the generated configuration
18001 with the @code{prosodyctl check} command.
18003 Prosodyctl will also help you to import certificates from the
18004 @code{letsencrypt} directory so that the @code{prosody} user can access
18005 them. See @url{https://prosody.im/doc/letsencrypt}.
18008 prosodyctl --root cert import /etc/letsencrypt/live
18011 The available configuration parameters follow. Each parameter
18012 definition is preceded by its type; for example, @samp{string-list foo}
18013 indicates that the @code{foo} parameter should be specified as a list of
18014 strings. Types starting with @code{maybe-} denote parameters that won't
18015 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
18017 There is also a way to specify the configuration as a string, if you
18018 have an old @code{prosody.cfg.lua} file that you want to port over from
18019 some other system; see the end for more details.
18021 The @code{file-object} type designates either a file-like object
18022 (@pxref{G-Expressions, file-like objects}) or a file name.
18024 @c The following documentation was initially generated by
18025 @c (generate-documentation) in (gnu services messaging). Manually maintained
18026 @c documentation is better, so we shouldn't hesitate to edit below as
18027 @c needed. However if the change you want to make to this documentation
18028 @c can be done in an automated way, it's probably easier to change
18029 @c (generate-documentation) than to make it below and have to deal with
18030 @c the churn as Prosody updates.
18032 Available @code{prosody-configuration} fields are:
18034 @deftypevr {@code{prosody-configuration} parameter} package prosody
18035 The Prosody package.
18038 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
18039 Location of the Prosody data storage directory. See
18040 @url{https://prosody.im/doc/configure}.
18041 Defaults to @samp{"/var/lib/prosody"}.
18044 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
18045 Additional plugin directories. They are searched in all the specified
18046 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
18047 Defaults to @samp{()}.
18050 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
18051 Every virtual host and component needs a certificate so that clients and
18052 servers can securely verify its identity. Prosody will automatically load
18053 certificates/keys from the directory specified here.
18054 Defaults to @samp{"/etc/prosody/certs"}.
18057 @deftypevr {@code{prosody-configuration} parameter} string-list admins
18058 This is a list of accounts that are admins for the server. Note that you
18059 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
18060 @url{https://prosody.im/doc/creating_accounts}.
18061 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
18062 Defaults to @samp{()}.
18065 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
18066 Enable use of libevent for better performance under high load. See
18067 @url{https://prosody.im/doc/libevent}.
18068 Defaults to @samp{#f}.
18071 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
18072 This is the list of modules Prosody will load on startup. It looks for
18073 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
18074 Documentation on modules can be found at:
18075 @url{https://prosody.im/doc/modules}.
18076 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
18079 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
18080 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
18081 should you want to disable them then add them to this list.
18082 Defaults to @samp{()}.
18085 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
18086 Path to a text file where the shared groups are defined. If this path is
18087 empty then @samp{mod_groups} does nothing. See
18088 @url{https://prosody.im/doc/modules/mod_groups}.
18089 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
18092 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
18093 Disable account creation by default, for security. See
18094 @url{https://prosody.im/doc/creating_accounts}.
18095 Defaults to @samp{#f}.
18098 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
18099 These are the SSL/TLS-related settings. Most of them are disabled so to
18100 use Prosody's defaults. If you do not completely understand these options, do
18101 not add them to your config, it is easy to lower the security of your server
18102 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
18104 Available @code{ssl-configuration} fields are:
18106 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
18107 This determines what handshake to use.
18110 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
18111 Path to your private key file.
18114 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
18115 Path to your certificate file.
18118 @deftypevr {@code{ssl-configuration} parameter} file-object capath
18119 Path to directory containing root certificates that you wish Prosody to
18120 trust when verifying the certificates of remote servers.
18121 Defaults to @samp{"/etc/ssl/certs"}.
18124 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
18125 Path to a file containing root certificates that you wish Prosody to trust.
18126 Similar to @code{capath} but with all certificates concatenated together.
18129 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
18130 A list of verification options (these mostly map to OpenSSL's
18131 @code{set_verify()} flags).
18134 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
18135 A list of general options relating to SSL/TLS. These map to OpenSSL's
18136 @code{set_options()}. For a full list of options available in LuaSec, see the
18140 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18141 How long a chain of certificate authorities to check when looking for a
18142 trusted root certificate.
18145 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18146 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18147 clients, and in what order.
18150 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18151 A path to a file containing parameters for Diffie-Hellman key exchange. You
18152 can create such a file with:
18153 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18156 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18157 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18158 @samp{"secp384r1"}.
18161 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18162 A list of "extra" verification options.
18165 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18166 Password for encrypted private keys.
18171 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18172 Whether to force all client-to-server connections to be encrypted or not.
18173 See @url{https://prosody.im/doc/modules/mod_tls}.
18174 Defaults to @samp{#f}.
18177 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18178 Set of mechanisms that will never be offered. See
18179 @url{https://prosody.im/doc/modules/mod_saslauth}.
18180 Defaults to @samp{("DIGEST-MD5")}.
18183 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18184 Whether to force all server-to-server connections to be encrypted or not.
18185 See @url{https://prosody.im/doc/modules/mod_tls}.
18186 Defaults to @samp{#f}.
18189 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18190 Whether to require encryption and certificate authentication. This
18191 provides ideal security, but requires servers you communicate with to support
18192 encryption AND present valid, trusted certificates. See
18193 @url{https://prosody.im/doc/s2s#security}.
18194 Defaults to @samp{#f}.
18197 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18198 Many servers don't support encryption or have invalid or self-signed
18199 certificates. You can list domains here that will not be required to
18200 authenticate using certificates. They will be authenticated using DNS. See
18201 @url{https://prosody.im/doc/s2s#security}.
18202 Defaults to @samp{()}.
18205 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18206 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18207 valid certificates for some domains by specifying a list here. See
18208 @url{https://prosody.im/doc/s2s#security}.
18209 Defaults to @samp{()}.
18212 @deftypevr {@code{prosody-configuration} parameter} string authentication
18213 Select the authentication backend to use. The default provider stores
18214 passwords in plaintext and uses Prosody's configured data storage to store the
18215 authentication data. If you do not trust your server please see
18216 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18217 about using the hashed backend. See also
18218 @url{https://prosody.im/doc/authentication}
18219 Defaults to @samp{"internal_plain"}.
18222 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18223 Set logging options. Advanced logging configuration is not yet supported
18224 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18225 Defaults to @samp{"*syslog"}.
18228 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18229 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18230 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18233 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18234 Maximum allowed size of the HTTP body (in bytes).
18237 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18238 Some modules expose their own URL in various ways. This URL is built
18239 from the protocol, host and port used. If Prosody sits behind a proxy, the
18240 public URL will be @code{http-external-url} instead. See
18241 @url{https://prosody.im/doc/http#external_url}.
18244 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18245 A host in Prosody is a domain on which user accounts can be created. For
18246 example if you want your users to have addresses like
18247 @samp{"john.smith@@example.com"} then you need to add a host
18248 @samp{"example.com"}. All options in this list will apply only to this host.
18250 Note: the name "virtual" host is used in configuration to avoid confusion with
18251 the actual physical host that Prosody is installed on. A single Prosody
18252 instance can serve many domains, each one defined as a VirtualHost entry in
18253 Prosody's configuration. Conversely a server that hosts a single domain would
18254 have just one VirtualHost entry.
18256 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18258 Available @code{virtualhost-configuration} fields are:
18260 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:
18261 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18262 Domain you wish Prosody to serve.
18267 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18268 Components are extra services on a server which are available to clients,
18269 usually on a subdomain of the main server (such as
18270 @samp{"mycomponent.example.com"}). Example components might be chatroom
18271 servers, user directories, or gateways to other protocols.
18273 Internal components are implemented with Prosody-specific plugins. To add an
18274 internal component, you simply fill the hostname field, and the plugin you wish
18275 to use for the component.
18277 See @url{https://prosody.im/doc/components}.
18278 Defaults to @samp{()}.
18280 Available @code{int-component-configuration} fields are:
18282 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:
18283 @deftypevr {@code{int-component-configuration} parameter} string hostname
18284 Hostname of the component.
18287 @deftypevr {@code{int-component-configuration} parameter} string plugin
18288 Plugin you wish to use for the component.
18291 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18292 Multi-user chat (MUC) is Prosody's module for allowing you to create
18293 hosted chatrooms/conferences for XMPP users.
18295 General information on setting up and using multi-user chatrooms can be found
18296 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
18297 which you should read if you are new to XMPP chatrooms.
18299 See also @url{https://prosody.im/doc/modules/mod_muc}.
18301 Available @code{mod-muc-configuration} fields are:
18303 @deftypevr {@code{mod-muc-configuration} parameter} string name
18304 The name to return in service discovery responses.
18305 Defaults to @samp{"Prosody Chatrooms"}.
18308 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18309 If @samp{#t}, this will only allow admins to create new chatrooms.
18310 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18311 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18312 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18313 restricts to service administrators only.
18314 Defaults to @samp{#f}.
18317 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18318 Maximum number of history messages that will be sent to the member that has
18319 just joined the room.
18320 Defaults to @samp{20}.
18327 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18328 External components use XEP-0114, which most standalone components
18329 support. To add an external component, you simply fill the hostname field. See
18330 @url{https://prosody.im/doc/components}.
18331 Defaults to @samp{()}.
18333 Available @code{ext-component-configuration} fields are:
18335 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:
18336 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18337 Password which the component will use to log in.
18340 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18341 Hostname of the component.
18346 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18347 Port(s) Prosody listens on for component connections.
18348 Defaults to @samp{(5347)}.
18351 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18352 Interface Prosody listens on for component connections.
18353 Defaults to @samp{"127.0.0.1"}.
18356 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18357 Raw content that will be added to the configuration file.
18360 It could be that you just want to get a @code{prosody.cfg.lua}
18361 up and running. In that case, you can pass an
18362 @code{opaque-prosody-configuration} record as the value of
18363 @code{prosody-service-type}. As its name indicates, an opaque configuration
18364 does not have easy reflective capabilities.
18365 Available @code{opaque-prosody-configuration} fields are:
18367 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18368 The prosody package.
18371 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18372 The contents of the @code{prosody.cfg.lua} to use.
18375 For example, if your @code{prosody.cfg.lua} is just the empty
18376 string, you could instantiate a prosody service like this:
18379 (service prosody-service-type
18380 (opaque-prosody-configuration
18381 (prosody.cfg.lua "")))
18384 @c end of Prosody auto-generated documentation
18386 @subsubheading BitlBee Service
18388 @cindex IRC (Internet Relay Chat)
18389 @cindex IRC gateway
18390 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18391 interface to a variety of messaging protocols such as XMPP.
18393 @defvr {Scheme Variable} bitlbee-service-type
18394 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18395 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18398 To have BitlBee listen on port 6667 on localhost, add this line to your
18402 (service bitlbee-service-type)
18406 @deftp {Data Type} bitlbee-configuration
18407 This is the configuration for BitlBee, with the following fields:
18410 @item @code{interface} (default: @code{"127.0.0.1"})
18411 @itemx @code{port} (default: @code{6667})
18412 Listen on the network interface corresponding to the IP address
18413 specified in @var{interface}, on @var{port}.
18415 When @var{interface} is @code{127.0.0.1}, only local clients can
18416 connect; when it is @code{0.0.0.0}, connections can come from any
18417 networking interface.
18419 @item @code{bitlbee} (default: @code{bitlbee})
18420 The BitlBee package to use.
18422 @item @code{plugins} (default: @code{'()})
18423 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18425 @item @code{extra-settings} (default: @code{""})
18426 Configuration snippet added as-is to the BitlBee configuration file.
18430 @subsubheading Quassel Service
18432 @cindex IRC (Internet Relay Chat)
18433 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18434 meaning that one or more clients can attach to and detach from the
18437 @defvr {Scheme Variable} quassel-service-type
18438 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18439 IRC backend daemon. Its value is a @code{quassel-configuration}
18443 @deftp {Data Type} quassel-configuration
18444 This is the configuration for Quassel, with the following fields:
18447 @item @code{quassel} (default: @code{quassel})
18448 The Quassel package to use.
18450 @item @code{interface} (default: @code{"::,0.0.0.0"})
18451 @item @code{port} (default: @code{4242})
18452 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18453 interfaces specified in the comma delimited @var{interface}, on
18456 @item @code{loglevel} (default: @code{"Info"})
18457 The level of logging desired. Accepted values are Debug, Info, Warning
18462 @node Telephony Services
18463 @subsection Telephony Services
18465 @cindex Murmur (VoIP server)
18466 @cindex VoIP server
18467 This section describes how to set up and run a Murmur server. Murmur is
18468 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18471 @deftp {Data Type} murmur-configuration
18472 The service type for the Murmur server. An example configuration can
18476 (service murmur-service-type
18477 (murmur-configuration
18479 "Welcome to this Mumble server running on Guix!")
18480 (cert-required? #t) ;disallow text password logins
18481 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18482 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18485 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18486 password with the command that is printed during the activation phase.
18488 It is recommended to register a normal Mumble user account
18489 and grant it admin or moderator rights.
18490 You can use the @code{mumble} client to
18491 login as new normal user, register yourself, and log out.
18492 For the next step login with the name @code{SuperUser} use
18493 the @code{SuperUser} password that you set previously,
18494 and grant your newly registered mumble user administrator or moderator
18495 rights and create some channels.
18497 Available @code{murmur-configuration} fields are:
18500 @item @code{package} (default: @code{mumble})
18501 Package that contains @code{bin/murmurd}.
18503 @item @code{user} (default: @code{"murmur"})
18504 User who will run the Murmur server.
18506 @item @code{group} (default: @code{"murmur"})
18507 Group of the user who will run the murmur server.
18509 @item @code{port} (default: @code{64738})
18510 Port on which the server will listen.
18512 @item @code{welcome-text} (default: @code{""})
18513 Welcome text sent to clients when they connect.
18515 @item @code{server-password} (default: @code{""})
18516 Password the clients have to enter in order to connect.
18518 @item @code{max-users} (default: @code{100})
18519 Maximum of users that can be connected to the server at once.
18521 @item @code{max-user-bandwidth} (default: @code{#f})
18522 Maximum voice traffic a user can send per second.
18524 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18525 File name of the sqlite database.
18526 The service's user will become the owner of the directory.
18528 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18529 File name of the log file.
18530 The service's user will become the owner of the directory.
18532 @item @code{autoban-attempts} (default: @code{10})
18533 Maximum number of logins a user can make in @code{autoban-timeframe}
18534 without getting auto banned for @code{autoban-time}.
18536 @item @code{autoban-timeframe} (default: @code{120})
18537 Timeframe for autoban in seconds.
18539 @item @code{autoban-time} (default: @code{300})
18540 Amount of time in seconds for which a client gets banned
18541 when violating the autoban limits.
18543 @item @code{opus-threshold} (default: @code{100})
18544 Percentage of clients that need to support opus
18545 before switching over to opus audio codec.
18547 @item @code{channel-nesting-limit} (default: @code{10})
18548 How deep channels can be nested at maximum.
18550 @item @code{channelname-regex} (default: @code{#f})
18551 A string in form of a Qt regular expression that channel names must conform to.
18553 @item @code{username-regex} (default: @code{#f})
18554 A string in form of a Qt regular expression that user names must conform to.
18556 @item @code{text-message-length} (default: @code{5000})
18557 Maximum size in bytes that a user can send in one text chat message.
18559 @item @code{image-message-length} (default: @code{(* 128 1024)})
18560 Maximum size in bytes that a user can send in one image message.
18562 @item @code{cert-required?} (default: @code{#f})
18563 If it is set to @code{#t} clients that use weak password authentication
18564 will not be accepted. Users must have completed the certificate wizard to join.
18566 @item @code{remember-channel?} (default: @code{#f})
18567 Should murmur remember the last channel each user was in when they disconnected
18568 and put them into the remembered channel when they rejoin.
18570 @item @code{allow-html?} (default: @code{#f})
18571 Should html be allowed in text messages, user comments, and channel descriptions.
18573 @item @code{allow-ping?} (default: @code{#f})
18574 Setting to true exposes the current user count, the maximum user count, and
18575 the server's maximum bandwidth per client to unauthenticated users. In the
18576 Mumble client, this information is shown in the Connect dialog.
18578 Disabling this setting will prevent public listing of the server.
18580 @item @code{bonjour?} (default: @code{#f})
18581 Should the server advertise itself in the local network through the bonjour protocol.
18583 @item @code{send-version?} (default: @code{#f})
18584 Should the murmur server version be exposed in ping requests.
18586 @item @code{log-days} (default: @code{31})
18587 Murmur also stores logs in the database, which are accessible via RPC.
18588 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
18589 or -1 to disable logging to the database.
18591 @item @code{obfuscate-ips?} (default: @code{#t})
18592 Should logged ips be obfuscated to protect the privacy of users.
18594 @item @code{ssl-cert} (default: @code{#f})
18595 File name of the SSL/TLS certificate used for encrypted connections.
18598 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
18600 @item @code{ssl-key} (default: @code{#f})
18601 Filepath to the ssl private key used for encrypted connections.
18603 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
18606 @item @code{ssl-dh-params} (default: @code{#f})
18607 File name of a PEM-encoded file with Diffie-Hellman parameters
18608 for the SSL/TLS encryption. Alternatively you set it to
18609 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
18610 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
18612 @item @code{ssl-ciphers} (default: @code{#f})
18613 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
18616 This option is specified using
18617 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
18618 OpenSSL cipher list notation}.
18620 It is recommended that you try your cipher string using 'openssl ciphers <string>'
18621 before setting it here, to get a feel for which cipher suites you will get.
18622 After setting this option, it is recommend that you inspect your Murmur log
18623 to ensure that Murmur is using the cipher suites that you expected it to.
18625 Note: Changing this option may impact the backwards compatibility of your
18626 Murmur server, and can remove the ability for older Mumble clients to be able
18629 @item @code{public-registration} (default: @code{#f})
18630 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
18632 You can optionally register your server in the public server list that the
18633 @code{mumble} client shows on startup.
18634 You cannot register your server if you have set a @code{server-password},
18635 or set @code{allow-ping} to @code{#f}.
18637 It might take a few hours until it shows up in the public list.
18639 @item @code{file} (default: @code{#f})
18640 Optional alternative override for this configuration.
18644 @deftp {Data Type} murmur-public-registration-configuration
18645 Configuration for public registration of a murmur service.
18649 This is a display name for your server. Not to be confused with the hostname.
18651 @item @code{password}
18652 A password to identify your registration.
18653 Subsequent updates will need the same password. Don't lose your password.
18656 This should be a @code{http://} or @code{https://} link to your web
18659 @item @code{hostname} (default: @code{#f})
18660 By default your server will be listed by its IP address.
18661 If it is set your server will be linked by this host name instead.
18667 @node Monitoring Services
18668 @subsection Monitoring Services
18670 @subsubheading Tailon Service
18672 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
18673 viewing and searching log files.
18675 The following example will configure the service with default values.
18676 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
18679 (service tailon-service-type)
18682 The following example customises more of the Tailon configuration,
18683 adding @command{sed} to the list of allowed commands.
18686 (service tailon-service-type
18687 (tailon-configuration
18689 (tailon-configuration-file
18690 (allowed-commands '("tail" "grep" "awk" "sed"))))))
18694 @deftp {Data Type} tailon-configuration
18695 Data type representing the configuration of Tailon.
18696 This type has the following parameters:
18699 @item @code{config-file} (default: @code{(tailon-configuration-file)})
18700 The configuration file to use for Tailon. This can be set to a
18701 @dfn{tailon-configuration-file} record value, or any gexp
18702 (@pxref{G-Expressions}).
18704 For example, to instead use a local file, the @code{local-file} function
18708 (service tailon-service-type
18709 (tailon-configuration
18710 (config-file (local-file "./my-tailon.conf"))))
18713 @item @code{package} (default: @code{tailon})
18714 The tailon package to use.
18719 @deftp {Data Type} tailon-configuration-file
18720 Data type representing the configuration options for Tailon.
18721 This type has the following parameters:
18724 @item @code{files} (default: @code{(list "/var/log")})
18725 List of files to display. The list can include strings for a single file
18726 or directory, or a list, where the first item is the name of a
18727 subsection, and the remaining items are the files or directories in that
18730 @item @code{bind} (default: @code{"localhost:8080"})
18731 Address and port to which Tailon should bind on.
18733 @item @code{relative-root} (default: @code{#f})
18734 URL path to use for Tailon, set to @code{#f} to not use a path.
18736 @item @code{allow-transfers?} (default: @code{#t})
18737 Allow downloading the log files in the web interface.
18739 @item @code{follow-names?} (default: @code{#t})
18740 Allow tailing of not-yet existent files.
18742 @item @code{tail-lines} (default: @code{200})
18743 Number of lines to read initially from each file.
18745 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18746 Commands to allow running. By default, @code{sed} is disabled.
18748 @item @code{debug?} (default: @code{#f})
18749 Set @code{debug?} to @code{#t} to show debug messages.
18751 @item @code{wrap-lines} (default: @code{#t})
18752 Initial line wrapping state in the web interface. Set to @code{#t} to
18753 initially wrap lines (the default), or to @code{#f} to initially not
18756 @item @code{http-auth} (default: @code{#f})
18757 HTTP authentication type to use. Set to @code{#f} to disable
18758 authentication (the default). Supported values are @code{"digest"} or
18761 @item @code{users} (default: @code{#f})
18762 If HTTP authentication is enabled (see @code{http-auth}), access will be
18763 restricted to the credentials provided here. To configure users, use a
18764 list of pairs, where the first element of the pair is the username, and
18765 the 2nd element of the pair is the password.
18768 (tailon-configuration-file
18769 (http-auth "basic")
18770 (users '(("user1" . "password1")
18771 ("user2" . "password2"))))
18778 @subsubheading Darkstat Service
18780 Darkstat is a packet sniffer that captures network traffic, calculates
18781 statistics about usage, and serves reports over HTTP.
18783 @defvar {Scheme Variable} darkstat-service-type
18784 This is the service type for the
18785 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18786 service, its value must be a @code{darkstat-configuration} record as in
18790 (service darkstat-service-type
18791 (darkstat-configuration
18792 (interface "eno1")))
18796 @deftp {Data Type} darkstat-configuration
18797 Data type representing the configuration of @command{darkstat}.
18800 @item @code{package} (default: @code{darkstat})
18801 The darkstat package to use.
18803 @item @code{interface}
18804 Capture traffic on the specified network interface.
18806 @item @code{port} (default: @code{"667"})
18807 Bind the web interface to the specified port.
18809 @item @code{bind-address} (default: @code{"127.0.0.1"})
18810 Bind the web interface to the specified address.
18812 @item @code{base} (default: @code{"/"})
18813 Specify the path of the base URL. This can be useful if
18814 @command{darkstat} is accessed via a reverse proxy.
18819 @subsubheading Prometheus Node Exporter Service
18821 @cindex prometheus-node-exporter
18822 The Prometheus ``node exporter'' makes hardware and operating system statistics
18823 provided by the Linux kernel available for the Prometheus monitoring system.
18824 This service should be deployed on all physical nodes and virtual machines,
18825 where monitoring these statistics is desirable.
18827 @defvar {Scheme variable} prometheus-node-exporter-service-type
18828 This is the service type for the
18829 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18830 service, its value must be a @code{prometheus-node-exporter-configuration}
18831 record as in this example:
18834 (service prometheus-node-exporter-service-type
18835 (prometheus-node-exporter-configuration
18836 (web-listen-address ":9100")))
18840 @deftp {Data Type} prometheus-node-exporter-configuration
18841 Data type representing the configuration of @command{node_exporter}.
18844 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18845 The prometheus-node-exporter package to use.
18847 @item @code{web-listen-address} (default: @code{":9100"})
18848 Bind the web interface to the specified address.
18853 @subsubheading Zabbix server
18854 @cindex zabbix zabbix-server
18855 Zabbix provides monitoring metrics, among others network utilization, CPU load
18856 and disk space consumption:
18859 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18860 @item Auto-discovery of servers and network devices and interfaces.
18861 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18862 @item Distributed monitoring with centralized web administration.
18863 @item Native high performance agents.
18864 @item SLA, and ITIL KPI metrics on reporting.
18865 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18866 @item Remote command execution through Zabbix proxies.
18869 @c %start of fragment
18871 Available @code{zabbix-server-configuration} fields are:
18873 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18874 The zabbix-server package.
18878 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18879 User who will run the Zabbix server.
18881 Defaults to @samp{"zabbix"}.
18885 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18886 Group who will run the Zabbix server.
18888 Defaults to @samp{"zabbix"}.
18892 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18893 Database host name.
18895 Defaults to @samp{"127.0.0.1"}.
18899 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18902 Defaults to @samp{"zabbix"}.
18906 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18909 Defaults to @samp{"zabbix"}.
18913 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18914 Database password. Please, use @code{include-files} with
18915 @code{DBPassword=SECRET} inside a specified file instead.
18917 Defaults to @samp{""}.
18921 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18924 Defaults to @samp{5432}.
18928 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18929 Specifies where log messages are written to:
18933 @code{system} - syslog.
18936 @code{file} - file specified with @code{log-file} parameter.
18939 @code{console} - standard output.
18943 Defaults to @samp{""}.
18947 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18948 Log file name for @code{log-type} @code{file} parameter.
18950 Defaults to @samp{"/var/log/zabbix/server.log"}.
18954 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18957 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18961 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18962 The location of certificate authority (CA) files for SSL server
18963 certificate verification.
18965 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18969 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18970 Location of SSL client certificates.
18972 Defaults to @samp{"/etc/ssl/certs"}.
18976 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18977 Extra options will be appended to Zabbix server configuration file.
18979 Defaults to @samp{""}.
18983 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18984 You may include individual files or all files in a directory in the
18985 configuration file.
18987 Defaults to @samp{()}.
18991 @c %end of fragment
18993 @subsubheading Zabbix agent
18994 @cindex zabbix zabbix-agent
18996 Zabbix agent gathers information for Zabbix server.
18998 @c %start of fragment
19000 Available @code{zabbix-agent-configuration} fields are:
19002 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
19003 The zabbix-agent package.
19007 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
19008 User who will run the Zabbix agent.
19010 Defaults to @samp{"zabbix"}.
19014 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
19015 Group who will run the Zabbix agent.
19017 Defaults to @samp{"zabbix"}.
19021 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
19022 Unique, case sensitive hostname which is required for active checks and
19023 must match hostname as configured on the server.
19025 Defaults to @samp{"Zabbix server"}.
19029 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
19030 Specifies where log messages are written to:
19034 @code{system} - syslog.
19037 @code{file} - file specified with @code{log-file} parameter.
19040 @code{console} - standard output.
19044 Defaults to @samp{""}.
19048 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
19049 Log file name for @code{log-type} @code{file} parameter.
19051 Defaults to @samp{"/var/log/zabbix/agent.log"}.
19055 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
19058 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
19062 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
19063 List of IP addresses, optionally in CIDR notation, or hostnames of
19064 Zabbix servers and Zabbix proxies. Incoming connections will be
19065 accepted only from the hosts listed here.
19067 Defaults to @samp{("127.0.0.1")}.
19071 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
19072 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
19073 proxies for active checks. If port is not specified, default port is
19074 used. If this parameter is not specified, active checks are disabled.
19076 Defaults to @samp{("127.0.0.1")}.
19080 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
19081 Extra options will be appended to Zabbix server configuration file.
19083 Defaults to @samp{""}.
19087 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
19088 You may include individual files or all files in a directory in the
19089 configuration file.
19091 Defaults to @samp{()}.
19095 @c %end of fragment
19097 @subsubheading Zabbix front-end
19098 @cindex zabbix zabbix-front-end
19100 This service provides a WEB interface to Zabbix server.
19102 @c %start of fragment
19104 Available @code{zabbix-front-end-configuration} fields are:
19106 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
19107 NGINX configuration.
19111 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
19112 Database host name.
19114 Defaults to @samp{"localhost"}.
19118 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
19121 Defaults to @samp{5432}.
19125 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
19128 Defaults to @samp{"zabbix"}.
19132 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
19135 Defaults to @samp{"zabbix"}.
19139 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19140 Database password. Please, use @code{db-secret-file} instead.
19142 Defaults to @samp{""}.
19146 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19147 Secret file which will be appended to @file{zabbix.conf.php} file. This
19148 file contains credentials for use by Zabbix front-end. You are expected
19149 to create it manually.
19151 Defaults to @samp{""}.
19155 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19156 Zabbix server hostname.
19158 Defaults to @samp{"localhost"}.
19162 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19163 Zabbix server port.
19165 Defaults to @samp{10051}.
19170 @c %end of fragment
19172 @node Kerberos Services
19173 @subsection Kerberos Services
19176 The @code{(gnu services kerberos)} module provides services relating to
19177 the authentication protocol @dfn{Kerberos}.
19179 @subsubheading Krb5 Service
19181 Programs using a Kerberos client library normally
19182 expect a configuration file in @file{/etc/krb5.conf}.
19183 This service generates such a file from a definition provided in the
19184 operating system declaration.
19185 It does not cause any daemon to be started.
19187 No ``keytab'' files are provided by this service---you must explicitly create them.
19188 This service is known to work with the MIT client library, @code{mit-krb5}.
19189 Other implementations have not been tested.
19191 @defvr {Scheme Variable} krb5-service-type
19192 A service type for Kerberos 5 clients.
19196 Here is an example of its use:
19198 (service krb5-service-type
19199 (krb5-configuration
19200 (default-realm "EXAMPLE.COM")
19201 (allow-weak-crypto? #t)
19204 (name "EXAMPLE.COM")
19205 (admin-server "groucho.example.com")
19206 (kdc "karl.example.com"))
19209 (admin-server "kerb-admin.argrx.edu")
19210 (kdc "keys.argrx.edu"))))))
19214 This example provides a Kerberos@tie{}5 client configuration which:
19216 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19217 of which have distinct administration servers and key distribution centers;
19218 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19219 specified by clients;
19220 @item Accepts services which only support encryption types known to be weak.
19223 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19224 Only the most commonly used ones are described here.
19225 For a full list, and more detailed explanation of each, see the MIT
19226 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19230 @deftp {Data Type} krb5-realm
19231 @cindex realm, kerberos
19234 This field is a string identifying the name of the realm.
19235 A common convention is to use the fully qualified DNS name of your organization,
19236 converted to upper case.
19238 @item @code{admin-server}
19239 This field is a string identifying the host where the administration server is
19243 This field is a string identifying the key distribution center
19248 @deftp {Data Type} krb5-configuration
19251 @item @code{allow-weak-crypto?} (default: @code{#f})
19252 If this flag is @code{#t} then services which only offer encryption algorithms
19253 known to be weak will be accepted.
19255 @item @code{default-realm} (default: @code{#f})
19256 This field should be a string identifying the default Kerberos
19257 realm for the client.
19258 You should set this field to the name of your Kerberos realm.
19259 If this value is @code{#f}
19260 then a realm must be specified with every Kerberos principal when invoking programs
19261 such as @command{kinit}.
19263 @item @code{realms}
19264 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19266 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19272 @subsubheading PAM krb5 Service
19275 The @code{pam-krb5} service allows for login authentication and password
19276 management via Kerberos.
19277 You will need this service if you want PAM enabled applications to authenticate
19278 users using Kerberos.
19280 @defvr {Scheme Variable} pam-krb5-service-type
19281 A service type for the Kerberos 5 PAM module.
19284 @deftp {Data Type} pam-krb5-configuration
19285 Data type representing the configuration of the Kerberos 5 PAM module.
19286 This type has the following parameters:
19288 @item @code{pam-krb5} (default: @code{pam-krb5})
19289 The pam-krb5 package to use.
19291 @item @code{minimum-uid} (default: @code{1000})
19292 The smallest user ID for which Kerberos authentications should be attempted.
19293 Local accounts with lower values will silently fail to authenticate.
19298 @node LDAP Services
19299 @subsection LDAP Services
19301 @cindex nslcd, LDAP service
19303 The @code{(gnu services authentication)} module provides the
19304 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19305 server. In addition to configuring the service itself, you may want to add
19306 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19307 Switch} for detailed information.
19309 Here is a simple operating system declaration with a default configuration of
19310 the @code{nslcd-service-type} and a Name Service Switch configuration that
19311 consults the @code{ldap} name service last:
19314 (use-service-modules authentication)
19315 (use-modules (gnu system nss))
19321 (service nslcd-service-type)
19322 (service dhcp-client-service-type)
19324 (name-service-switch
19325 (let ((services (list (name-service (name "db"))
19326 (name-service (name "files"))
19327 (name-service (name "ldap")))))
19328 (name-service-switch
19329 (inherit %mdns-host-lookup-nss)
19330 (password services)
19333 (netgroup services)
19334 (gshadow services)))))
19337 @c %start of generated documentation for nslcd-configuration
19339 Available @code{nslcd-configuration} fields are:
19341 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19342 The @code{nss-pam-ldapd} package to use.
19346 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19347 The number of threads to start that can handle requests and perform LDAP
19348 queries. Each thread opens a separate connection to the LDAP server.
19349 The default is to start 5 threads.
19351 Defaults to @samp{disabled}.
19355 @deftypevr {@code{nslcd-configuration} parameter} string uid
19356 This specifies the user id with which the daemon should be run.
19358 Defaults to @samp{"nslcd"}.
19362 @deftypevr {@code{nslcd-configuration} parameter} string gid
19363 This specifies the group id with which the daemon should be run.
19365 Defaults to @samp{"nslcd"}.
19369 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19370 This option controls the way logging is done via a list containing
19371 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
19372 or "syslog", or an absolute file name. The LEVEL argument is optional
19373 and specifies the log level. The log level may be one of the following
19374 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
19375 messages with the specified log level or higher are logged.
19377 Defaults to @samp{("/var/log/nslcd" info)}.
19381 @deftypevr {@code{nslcd-configuration} parameter} list uri
19382 The list of LDAP server URIs. Normally, only the first server will be
19383 used with the following servers as fall-back.
19385 Defaults to @samp{("ldap://localhost:389/")}.
19389 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19390 The version of the LDAP protocol to use. The default is to use the
19391 maximum version supported by the LDAP library.
19393 Defaults to @samp{disabled}.
19397 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19398 Specifies the distinguished name with which to bind to the directory
19399 server for lookups. The default is to bind anonymously.
19401 Defaults to @samp{disabled}.
19405 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19406 Specifies the credentials with which to bind. This option is only
19407 applicable when used with binddn.
19409 Defaults to @samp{disabled}.
19413 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19414 Specifies the distinguished name to use when the root user tries to
19415 modify a user's password using the PAM module.
19417 Defaults to @samp{disabled}.
19421 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19422 Specifies the credentials with which to bind if the root user tries to
19423 change a user's password. This option is only applicable when used with
19426 Defaults to @samp{disabled}.
19430 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19431 Specifies the SASL mechanism to be used when performing SASL
19434 Defaults to @samp{disabled}.
19438 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19439 Specifies the SASL realm to be used when performing SASL authentication.
19441 Defaults to @samp{disabled}.
19445 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19446 Specifies the authentication identity to be used when performing SASL
19449 Defaults to @samp{disabled}.
19453 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19454 Specifies the authorization identity to be used when performing SASL
19457 Defaults to @samp{disabled}.
19461 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19462 Determines whether the LDAP server host name should be canonicalised. If
19463 this is enabled the LDAP library will do a reverse host name lookup. By
19464 default, it is left up to the LDAP library whether this check is
19467 Defaults to @samp{disabled}.
19471 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19472 Set the name for the GSS-API Kerberos credentials cache.
19474 Defaults to @samp{disabled}.
19478 @deftypevr {@code{nslcd-configuration} parameter} string base
19479 The directory search base.
19481 Defaults to @samp{"dc=example,dc=com"}.
19485 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19486 Specifies the search scope (subtree, onelevel, base or children). The
19487 default scope is subtree; base scope is almost never useful for name
19488 service lookups; children scope is not supported on all servers.
19490 Defaults to @samp{(subtree)}.
19494 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19495 Specifies the policy for dereferencing aliases. The default policy is
19496 to never dereference aliases.
19498 Defaults to @samp{disabled}.
19502 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19503 Specifies whether automatic referral chasing should be enabled. The
19504 default behaviour is to chase referrals.
19506 Defaults to @samp{disabled}.
19510 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19511 This option allows for custom attributes to be looked up instead of the
19512 default RFC 2307 attributes. It is a list of maps, each consisting of
19513 the name of a map, the RFC 2307 attribute to match and the query
19514 expression for the attribute as it is available in the directory.
19516 Defaults to @samp{()}.
19520 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19521 A list of filters consisting of the name of a map to which the filter
19522 applies and an LDAP search filter expression.
19524 Defaults to @samp{()}.
19528 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19529 Specifies the time limit in seconds to use when connecting to the
19530 directory server. The default value is 10 seconds.
19532 Defaults to @samp{disabled}.
19536 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19537 Specifies the time limit (in seconds) to wait for a response from the
19538 LDAP server. A value of zero, which is the default, is to wait
19539 indefinitely for searches to be completed.
19541 Defaults to @samp{disabled}.
19545 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19546 Specifies the period if inactivity (in seconds) after which the con‐
19547 nection to the LDAP server will be closed. The default is not to time
19550 Defaults to @samp{disabled}.
19554 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19555 Specifies the number of seconds to sleep when connecting to all LDAP
19556 servers fails. By default one second is waited between the first
19557 failure and the first retry.
19559 Defaults to @samp{disabled}.
19563 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19564 Specifies the time after which the LDAP server is considered to be
19565 permanently unavailable. Once this time is reached retries will be done
19566 only once per this time period. The default value is 10 seconds.
19568 Defaults to @samp{disabled}.
19572 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
19573 Specifies whether to use SSL/TLS or not (the default is not to). If
19574 'start-tls is specified then StartTLS is used rather than raw LDAP over
19577 Defaults to @samp{disabled}.
19581 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
19582 Specifies what checks to perform on a server-supplied certificate. The
19583 meaning of the values is described in the ldap.conf(5) manual page.
19585 Defaults to @samp{disabled}.
19589 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
19590 Specifies the directory containing X.509 certificates for peer authen‐
19591 tication. This parameter is ignored when using GnuTLS.
19593 Defaults to @samp{disabled}.
19597 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
19598 Specifies the path to the X.509 certificate for peer authentication.
19600 Defaults to @samp{disabled}.
19604 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
19605 Specifies the path to an entropy source. This parameter is ignored when
19608 Defaults to @samp{disabled}.
19612 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
19613 Specifies the ciphers to use for TLS as a string.
19615 Defaults to @samp{disabled}.
19619 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
19620 Specifies the path to the file containing the local certificate for
19621 client TLS authentication.
19623 Defaults to @samp{disabled}.
19627 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
19628 Specifies the path to the file containing the private key for client TLS
19631 Defaults to @samp{disabled}.
19635 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
19636 Set this to a number greater than 0 to request paged results from the
19637 LDAP server in accordance with RFC2696. The default (0) is to not
19638 request paged results.
19640 Defaults to @samp{disabled}.
19644 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
19645 This option prevents group membership lookups through LDAP for the
19646 specified users. Alternatively, the value 'all-local may be used. With
19647 that value nslcd builds a full list of non-LDAP users on startup.
19649 Defaults to @samp{disabled}.
19653 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
19654 This option ensures that LDAP users with a numeric user id lower than
19655 the specified value are ignored.
19657 Defaults to @samp{disabled}.
19661 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
19662 This option specifies an offset that is added to all LDAP numeric user
19663 ids. This can be used to avoid user id collisions with local users.
19665 Defaults to @samp{disabled}.
19669 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
19670 This option specifies an offset that is added to all LDAP numeric group
19671 ids. This can be used to avoid user id collisions with local groups.
19673 Defaults to @samp{disabled}.
19677 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
19678 If this option is set, the member attribute of a group may point to
19679 another group. Members of nested groups are also returned in the higher
19680 level group and parent groups are returned when finding groups for a
19681 specific user. The default is not to perform extra searches for nested
19684 Defaults to @samp{disabled}.
19688 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
19689 If this option is set, the group member list is not retrieved when
19690 looking up groups. Lookups for finding which groups a user belongs to
19691 will remain functional so the user will likely still get the correct
19692 groups assigned on login.
19694 Defaults to @samp{disabled}.
19698 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
19699 If this option is set, functions which cause all user/group entries to
19700 be loaded from the directory will not succeed in doing so. This can
19701 dramatically reduce LDAP server load in situations where there are a
19702 great number of users and/or groups. This option is not recommended for
19703 most configurations.
19705 Defaults to @samp{disabled}.
19709 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19710 This option can be used to specify how user and group names are verified
19711 within the system. This pattern is used to check all user and group
19712 names that are requested and returned from LDAP.
19714 Defaults to @samp{disabled}.
19718 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19719 This specifies whether or not to perform searches using case-insensitive
19720 matching. Enabling this could open up the system to authorization
19721 bypass vulnerabilities and introduce nscd cache poisoning
19722 vulnerabilities which allow denial of service.
19724 Defaults to @samp{disabled}.
19728 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19729 This option specifies whether password policy controls are requested and
19730 handled from the LDAP server when performing user authentication.
19732 Defaults to @samp{disabled}.
19736 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19737 By default nslcd performs an LDAP search with the user's credentials
19738 after BIND (authentication) to ensure that the BIND operation was
19739 successful. The default search is a simple check to see if the user's
19740 DN exists. A search filter can be specified that will be used instead.
19741 It should return at least one entry.
19743 Defaults to @samp{disabled}.
19747 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19748 This option allows flexible fine tuning of the authorisation check that
19749 should be performed. The search filter specified is executed and if any
19750 entries match, access is granted, otherwise access is denied.
19752 Defaults to @samp{disabled}.
19756 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19757 If this option is set password modification using pam_ldap will be
19758 denied and the specified message will be presented to the user instead.
19759 The message can be used to direct the user to an alternative means of
19760 changing their password.
19762 Defaults to @samp{disabled}.
19766 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19767 List of pam service names for which LDAP authentication should suffice.
19769 Defaults to @samp{()}.
19773 @c %end of generated documentation for nslcd-configuration
19777 @subsection Web Services
19782 The @code{(gnu services web)} module provides the Apache HTTP Server,
19783 the nginx web server, and also a fastcgi wrapper daemon.
19785 @subsubheading Apache HTTP Server
19787 @deffn {Scheme Variable} httpd-service-type
19788 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19789 (@dfn{httpd}). The value for this service type is a
19790 @code{httpd-configuration} record.
19792 A simple example configuration is given below.
19795 (service httpd-service-type
19796 (httpd-configuration
19799 (server-name "www.example.com")
19800 (document-root "/srv/http/www.example.com")))))
19803 Other services can also extend the @code{httpd-service-type} to add to
19807 (simple-service 'www.example.com-server httpd-service-type
19811 (list (string-join '("ServerName www.example.com"
19812 "DocumentRoot /srv/http/www.example.com")
19817 The details for the @code{httpd-configuration}, @code{httpd-module},
19818 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19821 @deffn {Data Type} httpd-configuration
19822 This data type represents the configuration for the httpd service.
19825 @item @code{package} (default: @code{httpd})
19826 The httpd package to use.
19828 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19829 The pid file used by the shepherd-service.
19831 @item @code{config} (default: @code{(httpd-config-file)})
19832 The configuration file to use with the httpd service. The default value
19833 is a @code{httpd-config-file} record, but this can also be a different
19834 G-expression that generates a file, for example a @code{plain-file}. A
19835 file outside of the store can also be specified through a string.
19840 @deffn {Data Type} httpd-module
19841 This data type represents a module for the httpd service.
19845 The name of the module.
19848 The file for the module. This can be relative to the httpd package being
19849 used, the absolute location of a file, or a G-expression for a file
19850 within the store, for example @code{(file-append mod-wsgi
19851 "/modules/mod_wsgi.so")}.
19856 @defvr {Scheme Variable} %default-httpd-modules
19857 A default list of @code{httpd-module} objects.
19860 @deffn {Data Type} httpd-config-file
19861 This data type represents a configuration file for the httpd service.
19864 @item @code{modules} (default: @code{%default-httpd-modules})
19865 The modules to load. Additional modules can be added here, or loaded by
19866 additional configuration.
19868 For example, in order to handle requests for PHP files, you can use Apache’s
19869 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19872 (service httpd-service-type
19873 (httpd-configuration
19878 (name "proxy_module")
19879 (file "modules/mod_proxy.so"))
19881 (name "proxy_fcgi_module")
19882 (file "modules/mod_proxy_fcgi.so"))
19883 %default-httpd-modules))
19884 (extra-config (list "\
19885 <FilesMatch \\.php$>
19886 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19887 </FilesMatch>"))))))
19888 (service php-fpm-service-type
19889 (php-fpm-configuration
19890 (socket "/var/run/php-fpm.sock")
19891 (socket-group "httpd")))
19894 @item @code{server-root} (default: @code{httpd})
19895 The @code{ServerRoot} in the configuration file, defaults to the httpd
19896 package. Directives including @code{Include} and @code{LoadModule} are
19897 taken as relative to the server root.
19899 @item @code{server-name} (default: @code{#f})
19900 The @code{ServerName} in the configuration file, used to specify the
19901 request scheme, hostname and port that the server uses to identify
19904 This doesn't need to be set in the server config, and can be specifyed
19905 in virtual hosts. The default is @code{#f} to not specify a
19908 @item @code{document-root} (default: @code{"/srv/http"})
19909 The @code{DocumentRoot} from which files will be served.
19911 @item @code{listen} (default: @code{'("80")})
19912 The list of values for the @code{Listen} directives in the config
19913 file. The value should be a list of strings, when each string can
19914 specify the port number to listen on, and optionally the IP address and
19917 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19918 The @code{PidFile} to use. This should match the @code{pid-file} set in
19919 the @code{httpd-configuration} so that the Shepherd service is
19920 configured correctly.
19922 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19923 The @code{ErrorLog} to which the server will log errors.
19925 @item @code{user} (default: @code{"httpd"})
19926 The @code{User} which the server will answer requests as.
19928 @item @code{group} (default: @code{"httpd"})
19929 The @code{Group} which the server will answer requests as.
19931 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19932 A flat list of strings and G-expressions which will be added to the end
19933 of the configuration file.
19935 Any values which the service is extended with will be appended to this
19941 @deffn {Data Type} httpd-virtualhost
19942 This data type represents a virtualhost configuration block for the httpd service.
19944 These should be added to the extra-config for the httpd-service.
19947 (simple-service 'www.example.com-server httpd-service-type
19951 (list (string-join '("ServerName www.example.com"
19952 "DocumentRoot /srv/http/www.example.com")
19957 @item @code{addresses-and-ports}
19958 The addresses and ports for the @code{VirtualHost} directive.
19960 @item @code{contents}
19961 The contents of the @code{VirtualHost} directive, this should be a list
19962 of strings and G-expressions.
19967 @subsubheading NGINX
19969 @deffn {Scheme Variable} nginx-service-type
19970 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19971 value for this service type is a @code{<nginx-configuration>} record.
19973 A simple example configuration is given below.
19976 (service nginx-service-type
19977 (nginx-configuration
19979 (list (nginx-server-configuration
19980 (server-name '("www.example.com"))
19981 (root "/srv/http/www.example.com"))))))
19984 In addition to adding server blocks to the service configuration
19985 directly, this service can be extended by other services to add server
19986 blocks, as in this example:
19989 (simple-service 'my-extra-server nginx-service-type
19990 (list (nginx-server-configuration
19991 (root "/srv/http/extra-website")
19992 (try-files (list "$uri" "$uri/index.html")))))
19996 At startup, @command{nginx} has not yet read its configuration file, so
19997 it uses a default file to log error messages. If it fails to load its
19998 configuration file, that is where error messages are logged. After the
19999 configuration file is loaded, the default error log file changes as per
20000 configuration. In our case, startup error messages can be found in
20001 @file{/var/run/nginx/logs/error.log}, and after configuration in
20002 @file{/var/log/nginx/error.log}. The second location can be changed
20003 with the @var{log-directory} configuration option.
20005 @deffn {Data Type} nginx-configuration
20006 This data type represents the configuration for NGinx. Some
20007 configuration can be done through this and the other provided record
20008 types, or alternatively, a config file can be provided.
20011 @item @code{nginx} (default: @code{nginx})
20012 The nginx package to use.
20014 @item @code{log-directory} (default: @code{"/var/log/nginx"})
20015 The directory to which NGinx will write log files.
20017 @item @code{run-directory} (default: @code{"/var/run/nginx"})
20018 The directory in which NGinx will create a pid file, and write temporary
20021 @item @code{server-blocks} (default: @code{'()})
20022 A list of @dfn{server blocks} to create in the generated configuration
20023 file, the elements should be of type
20024 @code{<nginx-server-configuration>}.
20026 The following example would setup NGinx to serve @code{www.example.com}
20027 from the @code{/srv/http/www.example.com} directory, without using
20030 (service nginx-service-type
20031 (nginx-configuration
20033 (list (nginx-server-configuration
20034 (server-name '("www.example.com"))
20035 (root "/srv/http/www.example.com"))))))
20038 @item @code{upstream-blocks} (default: @code{'()})
20039 A list of @dfn{upstream blocks} to create in the generated configuration
20040 file, the elements should be of type
20041 @code{<nginx-upstream-configuration>}.
20043 Configuring upstreams through the @code{upstream-blocks} can be useful
20044 when combined with @code{locations} in the
20045 @code{<nginx-server-configuration>} records. The following example
20046 creates a server configuration with one location configuration, that
20047 will proxy requests to a upstream configuration, which will handle
20048 requests with two servers.
20053 (nginx-configuration
20055 (list (nginx-server-configuration
20056 (server-name '("www.example.com"))
20057 (root "/srv/http/www.example.com")
20060 (nginx-location-configuration
20062 (body '("proxy_pass http://server-proxy;"))))))))
20064 (list (nginx-upstream-configuration
20065 (name "server-proxy")
20066 (servers (list "server1.example.com"
20067 "server2.example.com")))))))
20070 @item @code{file} (default: @code{#f})
20071 If a configuration @var{file} is provided, this will be used, rather than
20072 generating a configuration file from the provided @code{log-directory},
20073 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
20074 proper operation, these arguments should match what is in @var{file} to ensure
20075 that the directories are created when the service is activated.
20077 This can be useful if you have an existing configuration file, or it's
20078 not possible to do what is required through the other parts of the
20079 nginx-configuration record.
20081 @item @code{server-names-hash-bucket-size} (default: @code{#f})
20082 Bucket size for the server names hash tables, defaults to @code{#f} to
20083 use the size of the processors cache line.
20085 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
20086 Maximum bucket size for the server names hash tables.
20088 @item @code{modules} (default: @code{'()})
20089 List of nginx dynamic modules to load. This should be a list of file
20090 names of loadable modules, as in this example:
20095 (file-append nginx-accept-language-module "\
20096 /etc/nginx/modules/ngx_http_accept_language_module.so")))
20099 @item @code{extra-content} (default: @code{""})
20100 Extra content for the @code{http} block. Should be string or a string
20101 valued G-expression.
20106 @deftp {Data Type} nginx-server-configuration
20107 Data type representing the configuration of an nginx server block.
20108 This type has the following parameters:
20111 @item @code{listen} (default: @code{'("80" "443 ssl")})
20112 Each @code{listen} directive sets the address and port for IP, or the
20113 path for a UNIX-domain socket on which the server will accept requests.
20114 Both address and port, or only address or only port can be specified.
20115 An address may also be a hostname, for example:
20118 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
20121 @item @code{server-name} (default: @code{(list 'default)})
20122 A list of server names this server represents. @code{'default} represents the
20123 default server for connections matching no other server.
20125 @item @code{root} (default: @code{"/srv/http"})
20126 Root of the website nginx will serve.
20128 @item @code{locations} (default: @code{'()})
20129 A list of @dfn{nginx-location-configuration} or
20130 @dfn{nginx-named-location-configuration} records to use within this
20133 @item @code{index} (default: @code{(list "index.html")})
20134 Index files to look for when clients ask for a directory. If it cannot be found,
20135 Nginx will send the list of files in the directory.
20137 @item @code{try-files} (default: @code{'()})
20138 A list of files whose existence is checked in the specified order.
20139 @code{nginx} will use the first file it finds to process the request.
20141 @item @code{ssl-certificate} (default: @code{#f})
20142 Where to find the certificate for secure connections. Set it to @code{#f} if
20143 you don't have a certificate or you don't want to use HTTPS.
20145 @item @code{ssl-certificate-key} (default: @code{#f})
20146 Where to find the private key for secure connections. Set it to @code{#f} if
20147 you don't have a key or you don't want to use HTTPS.
20149 @item @code{server-tokens?} (default: @code{#f})
20150 Whether the server should add its configuration to response.
20152 @item @code{raw-content} (default: @code{'()})
20153 A list of raw lines added to the server block.
20158 @deftp {Data Type} nginx-upstream-configuration
20159 Data type representing the configuration of an nginx @code{upstream}
20160 block. This type has the following parameters:
20164 Name for this group of servers.
20166 @item @code{servers}
20167 Specify the addresses of the servers in the group. The address can be
20168 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20169 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20170 prefix @samp{unix:}. For addresses using an IP address or domain name,
20171 the default port is 80, and a different port can be specified
20177 @deftp {Data Type} nginx-location-configuration
20178 Data type representing the configuration of an nginx @code{location}
20179 block. This type has the following parameters:
20183 URI which this location block matches.
20185 @anchor{nginx-location-configuration body}
20187 Body of the location block, specified as a list of strings. This can contain
20189 configuration directives. For example, to pass requests to a upstream
20190 server group defined using an @code{nginx-upstream-configuration} block,
20191 the following directive would be specified in the body @samp{(list "proxy_pass
20192 http://upstream-name;")}.
20197 @deftp {Data Type} nginx-named-location-configuration
20198 Data type representing the configuration of an nginx named location
20199 block. Named location blocks are used for request redirection, and not
20200 used for regular request processing. This type has the following
20205 Name to identify this location block.
20208 @xref{nginx-location-configuration body}, as the body for named location
20209 blocks can be used in a similar way to the
20210 @code{nginx-location-configuration body}. One restriction is that the
20211 body of a named location block cannot contain location blocks.
20216 @subsubheading Varnish Cache
20218 Varnish is a fast cache server that sits in between web applications
20219 and end users. It proxies requests from clients and caches the
20220 accessed URLs such that multiple requests for the same resource only
20221 creates one request to the back-end.
20223 @defvr {Scheme Variable} varnish-service-type
20224 Service type for the Varnish daemon.
20227 @deftp {Data Type} varnish-configuration
20228 Data type representing the @code{varnish} service configuration.
20229 This type has the following parameters:
20232 @item @code{package} (default: @code{varnish})
20233 The Varnish package to use.
20235 @item @code{name} (default: @code{"default"})
20236 A name for this Varnish instance. Varnish will create a directory in
20237 @file{/var/varnish/} with this name and keep temporary files there. If
20238 the name starts with a forward slash, it is interpreted as an absolute
20241 Pass the @code{-n} argument to other Varnish programs to connect to the
20242 named instance, e.g.@: @command{varnishncsa -n default}.
20244 @item @code{backend} (default: @code{"localhost:8080"})
20245 The backend to use. This option has no effect if @code{vcl} is set.
20247 @item @code{vcl} (default: #f)
20248 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20249 is @code{#f}, Varnish will proxy @code{backend} using the default
20250 configuration. Otherwise this must be a file-like object with valid
20253 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20254 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
20255 can do something along these lines:
20258 (define %gnu-mirror
20259 (plain-file "gnu.vcl"
20261 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20265 (services (cons (service varnish-service-type
20266 (varnish-configuration
20268 (vcl %gnu-mirror)))
20272 The configuration of an already running Varnish instance can be inspected
20273 and changed using the @command{varnishadm} program.
20275 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20276 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20277 comprehensive documentation on Varnish and its configuration language.
20279 @item @code{listen} (default: @code{'("localhost:80")})
20280 List of addresses Varnish will listen on.
20282 @item @code{storage} (default: @code{'("malloc,128m")})
20283 List of storage backends that will be available in VCL.
20285 @item @code{parameters} (default: @code{'()})
20286 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20288 @item @code{extra-options} (default: @code{'()})
20289 Additional arguments to pass to the @command{varnishd} process.
20294 @subsubheading Patchwork
20296 Patchwork is a patch tracking system. It can collect patches sent to a
20297 mailing list, and display them in a web interface.
20299 @defvr {Scheme Variable} patchwork-service-type
20300 Service type for Patchwork.
20303 The following example is an example of a minimal service for Patchwork, for
20304 the @code{patchwork.example.com} domain.
20307 (service patchwork-service-type
20308 (patchwork-configuration
20309 (domain "patchwork.example.com")
20311 (patchwork-settings-module
20312 (allowed-hosts (list domain))
20313 (default-from-email "patchwork@@patchwork.example.com")))
20314 (getmail-retriever-config
20315 (getmail-retriever-configuration
20316 (type "SimpleIMAPSSLRetriever")
20317 (server "imap.example.com")
20319 (username "patchwork")
20321 (list (file-append coreutils "/bin/cat")
20322 "/etc/getmail-patchwork-imap-password"))
20324 '((mailboxes . ("Patches"))))))))
20328 There are three records for configuring the Patchwork service. The
20329 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20330 within the HTTPD service.
20332 The @code{settings-module} field within the @code{<patchwork-configuration>}
20333 record can be populated with the @code{<patchwork-settings-module>} record,
20334 which describes a settings module that is generated within the Guix store.
20336 For the @code{database-configuration} field within the
20337 @code{<patchwork-settings-module>}, the
20338 @code{<patchwork-database-configuration>} must be used.
20340 @deftp {Data Type} patchwork-configuration
20341 Data type representing the Patchwork service configuration. This type has the
20342 following parameters:
20345 @item @code{patchwork} (default: @code{patchwork})
20346 The Patchwork package to use.
20348 @item @code{domain}
20349 The domain to use for Patchwork, this is used in the HTTPD service virtual
20352 @item @code{settings-module}
20353 The settings module to use for Patchwork. As a Django application, Patchwork
20354 is configured with a Python module containing the settings. This can either be
20355 an instance of the @code{<patchwork-settings-module>} record, any other record
20356 that represents the settings in the store, or a directory outside of the
20359 @item @code{static-path} (default: @code{"/static/"})
20360 The path under which the HTTPD service should serve the static files.
20362 @item @code{getmail-retriever-config}
20363 The getmail-retriever-configuration record value to use with
20364 Patchwork. Getmail will be configured with this value, the messages will be
20365 delivered to Patchwork.
20370 @deftp {Data Type} patchwork-settings-module
20371 Data type representing a settings module for Patchwork. Some of these
20372 settings relate directly to Patchwork, but others relate to Django, the web
20373 framework used by Patchwork, or the Django Rest Framework library. This type
20374 has the following parameters:
20377 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20378 The database connection settings used for Patchwork. See the
20379 @code{<patchwork-database-configuration>} record type for more information.
20381 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20382 Patchwork, as a Django web application uses a secret key for cryptographically
20383 signing values. This file should contain a unique unpredictable value.
20385 If this file does not exist, it will be created and populated with a random
20386 value by the patchwork-setup shepherd service.
20388 This setting relates to Django.
20390 @item @code{allowed-hosts}
20391 A list of valid hosts for this Patchwork service. This should at least include
20392 the domain specified in the @code{<patchwork-configuration>} record.
20394 This is a Django setting.
20396 @item @code{default-from-email}
20397 The email address from which Patchwork should send email by default.
20399 This is a Patchwork setting.
20401 @item @code{static-url} (default: @code{#f})
20402 The URL to use when serving static assets. It can be part of a URL, or a full
20403 URL, but must end in a @code{/}.
20405 If the default value is used, the @code{static-path} value from the
20406 @code{<patchwork-configuration>} record will be used.
20408 This is a Django setting.
20410 @item @code{admins} (default: @code{'()})
20411 Email addresses to send the details of errors that occur. Each value should
20412 be a list containing two elements, the name and then the email address.
20414 This is a Django setting.
20416 @item @code{debug?} (default: @code{#f})
20417 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20418 messages will be shown.
20420 This is a Django setting.
20422 @item @code{enable-rest-api?} (default: @code{#t})
20423 Whether to enable the Patchwork REST API.
20425 This is a Patchwork setting.
20427 @item @code{enable-xmlrpc?} (default: @code{#t})
20428 Whether to enable the XML RPC API.
20430 This is a Patchwork setting.
20432 @item @code{force-https-links?} (default: @code{#t})
20433 Whether to use HTTPS links on Patchwork pages.
20435 This is a Patchwork setting.
20437 @item @code{extra-settings} (default: @code{""})
20438 Extra code to place at the end of the Patchwork settings module.
20443 @deftp {Data Type} patchwork-database-configuration
20444 Data type representing the database configuration for Patchwork.
20447 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20448 The database engine to use.
20450 @item @code{name} (default: @code{"patchwork"})
20451 The name of the database to use.
20453 @item @code{user} (default: @code{"httpd"})
20454 The user to connect to the database as.
20456 @item @code{password} (default: @code{""})
20457 The password to use when connecting to the database.
20459 @item @code{host} (default: @code{""})
20460 The host to make the database connection to.
20462 @item @code{port} (default: @code{""})
20463 The port on which to connect to the database.
20468 @subsubheading Mumi
20470 @cindex Mumi, Debbugs Web interface
20471 @cindex Debbugs, Mumi Web interface
20472 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
20473 Web interface to the Debbugs bug tracker, by default for
20474 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
20475 but it also fetches and indexes mail retrieved from Debbugs.
20477 @defvr {Scheme Variable} mumi-service-type
20478 This is the service type for Mumi.
20481 @subsubheading FastCGI
20484 FastCGI is an interface between the front-end and the back-end of a web
20485 service. It is a somewhat legacy facility; new web services should
20486 generally just talk HTTP between the front-end and the back-end.
20487 However there are a number of back-end services such as PHP or the
20488 optimized HTTP Git repository access that use FastCGI, so we have
20489 support for it in Guix.
20491 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20492 dispatch some subset of its requests to the fastcgi backend, which
20493 listens on a local TCP or UNIX socket. There is an intermediary
20494 @code{fcgiwrap} program that sits between the actual backend process and
20495 the web server. The front-end indicates which backend program to run,
20496 passing that information to the @code{fcgiwrap} process.
20498 @defvr {Scheme Variable} fcgiwrap-service-type
20499 A service type for the @code{fcgiwrap} FastCGI proxy.
20502 @deftp {Data Type} fcgiwrap-configuration
20503 Data type representing the configuration of the @code{fcgiwrap} service.
20504 This type has the following parameters:
20506 @item @code{package} (default: @code{fcgiwrap})
20507 The fcgiwrap package to use.
20509 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20510 The socket on which the @code{fcgiwrap} process should listen, as a
20511 string. Valid @var{socket} values include
20512 @code{unix:@var{/path/to/unix/socket}},
20513 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20514 @code{tcp6:[@var{ipv6_addr}]:port}.
20516 @item @code{user} (default: @code{fcgiwrap})
20517 @itemx @code{group} (default: @code{fcgiwrap})
20518 The user and group names, as strings, under which to run the
20519 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20520 the user asks for the specific user or group names @code{fcgiwrap} that
20521 the corresponding user and/or group is present on the system.
20523 It is possible to configure a FastCGI-backed web service to pass HTTP
20524 authentication information from the front-end to the back-end, and to
20525 allow @code{fcgiwrap} to run the back-end process as a corresponding
20526 local user. To enable this capability on the back-end, run
20527 @code{fcgiwrap} as the @code{root} user and group. Note that this
20528 capability also has to be configured on the front-end as well.
20533 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20534 with some additional features useful for sites of any size.
20536 These features include:
20538 @item Adaptive process spawning
20539 @item Basic statistics (similar to Apache's mod_status)
20540 @item Advanced process management with graceful stop/start
20541 @item Ability to start workers with different uid/gid/chroot/environment
20542 and different php.ini (replaces safe_mode)
20543 @item Stdout & stderr logging
20544 @item Emergency restart in case of accidental opcode cache destruction
20545 @item Accelerated upload support
20546 @item Support for a "slowlog"
20547 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
20548 a special function to finish request & flush all data while continuing to do
20549 something time-consuming (video converting, stats processing, etc.)
20551 ...@: and much more.
20553 @defvr {Scheme Variable} php-fpm-service-type
20554 A Service type for @code{php-fpm}.
20557 @deftp {Data Type} php-fpm-configuration
20558 Data Type for php-fpm service configuration.
20560 @item @code{php} (default: @code{php})
20561 The php package to use.
20562 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
20563 The address on which to accept FastCGI requests. Valid syntaxes are:
20565 @item @code{"ip.add.re.ss:port"}
20566 Listen on a TCP socket to a specific address on a specific port.
20567 @item @code{"port"}
20568 Listen on a TCP socket to all addresses on a specific port.
20569 @item @code{"/path/to/unix/socket"}
20570 Listen on a unix socket.
20573 @item @code{user} (default: @code{php-fpm})
20574 User who will own the php worker processes.
20575 @item @code{group} (default: @code{php-fpm})
20576 Group of the worker processes.
20577 @item @code{socket-user} (default: @code{php-fpm})
20578 User who can speak to the php-fpm socket.
20579 @item @code{socket-group} (default: @code{nginx})
20580 Group that can speak to the php-fpm socket.
20581 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
20582 The process id of the php-fpm process is written to this file
20583 once the service has started.
20584 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
20585 Log for the php-fpm master process.
20586 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
20587 Detailed settings for the php-fpm process manager.
20590 @item @code{<php-fpm-dynamic-process-manager-configuration>}
20591 @item @code{<php-fpm-static-process-manager-configuration>}
20592 @item @code{<php-fpm-on-demand-process-manager-configuration>}
20594 @item @code{display-errors} (default @code{#f})
20595 Determines whether php errors and warning should be sent to clients
20596 and displayed in their browsers.
20597 This is useful for local php development, but a security risk for public sites,
20598 as error messages can reveal passwords and personal data.
20599 @item @code{timezone} (default @code{#f})
20600 Specifies @code{php_admin_value[date.timezone]} parameter.
20601 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
20602 This file will log the @code{stderr} outputs of php worker processes.
20603 Can be set to @code{#f} to disable logging.
20604 @item @code{file} (default @code{#f})
20605 An optional override of the whole configuration.
20606 You can use the @code{mixed-text-file} function or an absolute filepath for it.
20610 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
20611 Data Type for the @code{dynamic} php-fpm process manager. With the
20612 @code{dynamic} process manager, spare worker processes are kept around
20613 based on it's configured limits.
20615 @item @code{max-children} (default: @code{5})
20616 Maximum of worker processes.
20617 @item @code{start-servers} (default: @code{2})
20618 How many worker processes should be started on start-up.
20619 @item @code{min-spare-servers} (default: @code{1})
20620 How many spare worker processes should be kept around at minimum.
20621 @item @code{max-spare-servers} (default: @code{3})
20622 How many spare worker processes should be kept around at maximum.
20626 @deftp {Data type} php-fpm-static-process-manager-configuration
20627 Data Type for the @code{static} php-fpm process manager. With the
20628 @code{static} process manager, an unchanging number of worker processes
20631 @item @code{max-children} (default: @code{5})
20632 Maximum of worker processes.
20636 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
20637 Data Type for the @code{on-demand} php-fpm process manager. With the
20638 @code{on-demand} process manager, worker processes are only created as
20641 @item @code{max-children} (default: @code{5})
20642 Maximum of worker processes.
20643 @item @code{process-idle-timeout} (default: @code{10})
20644 The time in seconds after which a process with no requests is killed.
20649 @deffn {Scheme Procedure} nginx-php-fpm-location @
20650 [#:nginx-package nginx] @
20651 [socket (string-append "/var/run/php" @
20652 (version-major (package-version php)) @
20654 A helper function to quickly add php to an @code{nginx-server-configuration}.
20657 A simple services setup for nginx with php can look like this:
20659 (services (cons* (service dhcp-client-service-type)
20660 (service php-fpm-service-type)
20661 (service nginx-service-type
20662 (nginx-server-configuration
20663 (server-name '("example.com"))
20664 (root "/srv/http/")
20666 (list (nginx-php-location)))
20668 (ssl-certificate #f)
20669 (ssl-certificate-key #f)))
20673 @cindex cat-avatar-generator
20674 The cat avatar generator is a simple service to demonstrate the use of php-fpm
20675 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
20676 the hash of a user's email address.
20678 @deffn {Scheme Procedure} cat-avatar-generator-service @
20679 [#:cache-dir "/var/cache/cat-avatar-generator"] @
20680 [#:package cat-avatar-generator] @
20681 [#:configuration (nginx-server-configuration)]
20682 Returns an nginx-server-configuration that inherits @code{configuration}. It
20683 extends the nginx configuration to add a server block that serves @code{package},
20684 a version of cat-avatar-generator. During execution, cat-avatar-generator will
20685 be able to use @code{cache-dir} as its cache directory.
20688 A simple setup for cat-avatar-generator can look like this:
20690 (services (cons* (cat-avatar-generator-service
20692 (nginx-server-configuration
20693 (server-name '("example.com"))))
20698 @subsubheading Hpcguix-web
20700 @cindex hpcguix-web
20701 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
20702 program is a customizable web interface to browse Guix packages,
20703 initially designed for users of high-performance computing (HPC)
20706 @defvr {Scheme Variable} hpcguix-web-service-type
20707 The service type for @code{hpcguix-web}.
20710 @deftp {Data Type} hpcguix-web-configuration
20711 Data type for the hpcguix-web service configuration.
20715 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
20716 configuration. The main items available in this spec are:
20719 @item @code{title-prefix} (default: @code{"hpcguix | "})
20720 The page title prefix.
20722 @item @code{guix-command} (default: @code{"guix"})
20723 The @command{guix} command.
20725 @item @code{package-filter-proc} (default: @code{(const #t)})
20726 A procedure specifying how to filter packages that are displayed.
20728 @item @code{package-page-extension-proc} (default: @code{(const '())})
20729 Extension package for @code{hpcguix-web}.
20731 @item @code{menu} (default: @code{'()})
20732 Additional entry in page @code{menu}.
20734 @item @code{channels} (default: @code{%default-channels})
20735 List of channels from which the package list is built (@pxref{Channels}).
20737 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20738 The expiration time, in seconds, after which the package list is rebuilt from
20739 the latest instances of the given channels.
20742 See the hpcguix-web repository for a
20743 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20746 @item @code{package} (default: @code{hpcguix-web})
20747 The hpcguix-web package to use.
20751 A typical hpcguix-web service declaration looks like this:
20754 (service hpcguix-web-service-type
20755 (hpcguix-web-configuration
20757 #~(define site-config
20758 (hpcweb-configuration
20759 (title-prefix "Guix-HPC - ")
20760 (menu '(("/about" "ABOUT"))))))))
20764 The hpcguix-web service periodically updates the package list it publishes by
20765 pulling channels from Git. To that end, it needs to access X.509 certificates
20766 so that it can authenticate Git servers when communicating over HTTPS, and it
20767 assumes that @file{/etc/ssl/certs} contains those certificates.
20769 Thus, make sure to add @code{nss-certs} or another certificate package to the
20770 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20771 more information on X.509 certificates.
20774 @node Certificate Services
20775 @subsection Certificate Services
20778 @cindex HTTP, HTTPS
20779 @cindex Let's Encrypt
20780 @cindex TLS certificates
20781 The @code{(gnu services certbot)} module provides a service to
20782 automatically obtain a valid TLS certificate from the Let's Encrypt
20783 certificate authority. These certificates can then be used to serve
20784 content securely over HTTPS or other TLS-based protocols, with the
20785 knowledge that the client will be able to verify the server's
20788 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20789 @code{certbot} tool to automate the certification process. This tool
20790 first securely generates a key on the server. It then makes a request
20791 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20792 checks that the request originates from the host in question by using a
20793 challenge-response protocol, requiring the server to provide its
20794 response over HTTP. If that protocol completes successfully, the CA
20795 signs the key, resulting in a certificate. That certificate is valid
20796 for a limited period of time, and therefore to continue to provide TLS
20797 services, the server needs to periodically ask the CA to renew its
20800 The certbot service automates this process: the initial key
20801 generation, the initial certification request to the Let's Encrypt
20802 service, the web server challenge/response integration, writing the
20803 certificate to disk, the automated periodic renewals, and the deployment
20804 tasks associated with the renewal (e.g.@: reloading services, copying keys
20805 with different permissions).
20807 Certbot is run twice a day, at a random minute within the hour. It
20808 won't do anything until your certificates are due for renewal or
20809 revoked, but running it regularly would give your service a chance of
20810 staying online in case a Let's Encrypt-initiated revocation happened for
20813 By using this service, you agree to the ACME Subscriber Agreement, which
20814 can be found there:
20815 @url{https://acme-v01.api.letsencrypt.org/directory}.
20817 @defvr {Scheme Variable} certbot-service-type
20818 A service type for the @code{certbot} Let's Encrypt client. Its value
20819 must be a @code{certbot-configuration} record as in this example:
20822 (define %nginx-deploy-hook
20824 "nginx-deploy-hook"
20825 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20826 (kill pid SIGHUP))))
20828 (service certbot-service-type
20829 (certbot-configuration
20830 (email "foo@@example.net")
20833 (certificate-configuration
20834 (domains '("example.net" "www.example.net"))
20835 (deploy-hook %nginx-deploy-hook))
20836 (certificate-configuration
20837 (domains '("bar.example.net")))))))
20840 See below for details about @code{certbot-configuration}.
20843 @deftp {Data Type} certbot-configuration
20844 Data type representing the configuration of the @code{certbot} service.
20845 This type has the following parameters:
20848 @item @code{package} (default: @code{certbot})
20849 The certbot package to use.
20851 @item @code{webroot} (default: @code{/var/www})
20852 The directory from which to serve the Let's Encrypt challenge/response
20855 @item @code{certificates} (default: @code{()})
20856 A list of @code{certificates-configuration}s for which to generate
20857 certificates and request signatures. Each certificate has a @code{name}
20858 and several @code{domains}.
20861 Mandatory email used for registration, recovery contact, and important
20862 account notifications.
20864 @item @code{rsa-key-size} (default: @code{2048})
20865 Size of the RSA key.
20867 @item @code{default-location} (default: @i{see below})
20868 The default @code{nginx-location-configuration}. Because @code{certbot}
20869 needs to be able to serve challenges and responses, it needs to be able
20870 to run a web server. It does so by extending the @code{nginx} web
20871 service with an @code{nginx-server-configuration} listening on the
20872 @var{domains} on port 80, and which has a
20873 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20874 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20875 these nginx configuration data types.
20877 Requests to other URL paths will be matched by the
20878 @code{default-location}, which if present is added to all
20879 @code{nginx-server-configuration}s.
20881 By default, the @code{default-location} will issue a redirect from
20882 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20883 you to define what to serve on your site via @code{https}.
20885 Pass @code{#f} to not issue a default location.
20889 @deftp {Data Type} certificate-configuration
20890 Data type representing the configuration of a certificate.
20891 This type has the following parameters:
20894 @item @code{name} (default: @i{see below})
20895 This name is used by Certbot for housekeeping and in file paths; it
20896 doesn't affect the content of the certificate itself. To see
20897 certificate names, run @code{certbot certificates}.
20899 Its default is the first provided domain.
20901 @item @code{domains} (default: @code{()})
20902 The first domain provided will be the subject CN of the certificate, and
20903 all domains will be Subject Alternative Names on the certificate.
20905 @item @code{challenge} (default: @code{#f})
20906 The challenge type that has to be run by certbot. If @code{#f} is specified,
20907 default to the HTTP challenge. If a value is specified, defaults to the
20908 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20909 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
20910 and gives Let's Encrypt permission to log the public IP address of the
20911 requesting machine.
20913 @item @code{authentication-hook} (default: @code{#f})
20914 Command to be run in a shell once for each certificate challenge to be
20915 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20916 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20917 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20918 file name of the resource requested when performing an HTTP-01 challenge.
20920 @item @code{cleanup-hook} (default: @code{#f})
20921 Command to be run in a shell once for each certificate challenge that
20922 have been answered by the @code{auth-hook}. For this command, the shell
20923 variables available in the @code{auth-hook} script are still available, and
20924 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20925 of the @code{auth-hook} script.
20927 @item @code{deploy-hook} (default: @code{#f})
20928 Command to be run in a shell once for each successfully issued
20929 certificate. For this command, the shell variable
20930 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20931 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20932 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20933 contain a space-delimited list of renewed certificate domains (for
20934 example, @samp{"example.com www.example.com"}.
20939 For each @code{certificate-configuration}, the certificate is saved to
20940 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20941 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20943 @subsection DNS Services
20944 @cindex DNS (domain name system)
20945 @cindex domain name system (DNS)
20947 The @code{(gnu services dns)} module provides services related to the
20948 @dfn{domain name system} (DNS). It provides a server service for hosting
20949 an @emph{authoritative} DNS server for multiple zones, slave or master.
20950 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20951 caching and forwarding DNS server for the LAN, which uses
20952 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20954 @subsubheading Knot Service
20956 An example configuration of an authoritative server for two zones, one master
20960 (define-zone-entries example.org.zone
20961 ;; Name TTL Class Type Data
20962 ("@@" "" "IN" "A" "127.0.0.1")
20963 ("@@" "" "IN" "NS" "ns")
20964 ("ns" "" "IN" "A" "127.0.0.1"))
20966 (define master-zone
20967 (knot-zone-configuration
20968 (domain "example.org")
20970 (origin "example.org")
20971 (entries example.org.zone)))))
20974 (knot-zone-configuration
20975 (domain "plop.org")
20976 (dnssec-policy "default")
20977 (master (list "plop-master"))))
20979 (define plop-master
20980 (knot-remote-configuration
20982 (address (list "208.76.58.171"))))
20986 (services (cons* (service knot-service-type
20987 (knot-configuration
20988 (remotes (list plop-master))
20989 (zones (list master-zone slave-zone))))
20994 @deffn {Scheme Variable} knot-service-type
20995 This is the type for the Knot DNS server.
20997 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20998 zones, that is to say domain names you would buy from a registrar. This server
20999 is not a resolver, meaning that it can only resolve names for which it is
21000 authoritative. This server can be configured to serve zones as a master server
21001 or a slave server as a per-zone basis. Slave zones will get their data from
21002 masters, and will serve it as an authoritative server. From the point of view
21003 of a resolver, there is no difference between master and slave.
21005 The following data types are used to configure the Knot DNS server:
21008 @deftp {Data Type} knot-key-configuration
21009 Data type representing a key.
21010 This type has the following parameters:
21013 @item @code{id} (default: @code{""})
21014 An identifier for other configuration fields to refer to this key. IDs must
21015 be unique and must not be empty.
21017 @item @code{algorithm} (default: @code{#f})
21018 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
21019 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
21020 and @code{'hmac-sha512}.
21022 @item @code{secret} (default: @code{""})
21023 The secret key itself.
21028 @deftp {Data Type} knot-acl-configuration
21029 Data type representing an Access Control List (ACL) configuration.
21030 This type has the following parameters:
21033 @item @code{id} (default: @code{""})
21034 An identifier for ether configuration fields to refer to this key. IDs must be
21035 unique and must not be empty.
21037 @item @code{address} (default: @code{'()})
21038 An ordered list of IP addresses, network subnets, or network ranges represented
21039 with strings. The query must match one of them. Empty value means that
21040 address match is not required.
21042 @item @code{key} (default: @code{'()})
21043 An ordered list of references to keys represented with strings. The string
21044 must match a key ID defined in a @code{knot-key-configuration}. No key means
21045 that a key is not require to match that ACL.
21047 @item @code{action} (default: @code{'()})
21048 An ordered list of actions that are permitted or forbidden by this ACL. Possible
21049 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
21050 and @code{'update}.
21052 @item @code{deny?} (default: @code{#f})
21053 When true, the ACL defines restrictions. Listed actions are forbidden. When
21054 false, listed actions are allowed.
21059 @deftp {Data Type} zone-entry
21060 Data type represnting a record entry in a zone file.
21061 This type has the following parameters:
21064 @item @code{name} (default: @code{"@@"})
21065 The name of the record. @code{"@@"} refers to the origin of the zone. Names
21066 are relative to the origin of the zone. For example, in the @code{example.org}
21067 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
21068 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
21069 refers to @code{ns.example.org}.
21071 @item @code{ttl} (default: @code{""})
21072 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
21074 @item @code{class} (default: @code{"IN"})
21075 The class of the record. Knot currently supports only @code{"IN"} and
21076 partially @code{"CH"}.
21078 @item @code{type} (default: @code{"A"})
21079 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
21080 address), NS (Name Server) and MX (Mail eXchange). Many other types are
21083 @item @code{data} (default: @code{""})
21084 The data contained in the record. For instance an IP address associated with
21085 an A record, or a domain name associated with an NS record. Remember that
21086 domain names are relative to the origin unless they end with a dot.
21091 @deftp {Data Type} zone-file
21092 Data type representing the content of a zone file.
21093 This type has the following parameters:
21096 @item @code{entries} (default: @code{'()})
21097 The list of entries. The SOA record is taken care of, so you don't need to
21098 put it in the list of entries. This list should probably contain an entry
21099 for your primary authoritative DNS server. Other than using a list of entries
21100 directly, you can use @code{define-zone-entries} to define a object containing
21101 the list of entries more easily, that you can later pass to the @code{entries}
21102 field of the @code{zone-file}.
21104 @item @code{origin} (default: @code{""})
21105 The name of your zone. This parameter cannot be empty.
21107 @item @code{ns} (default: @code{"ns"})
21108 The domain of your primary authoritative DNS server. The name is relative to
21109 the origin, unless it ends with a dot. It is mandatory that this primary
21110 DNS server corresponds to an NS record in the zone and that it is associated
21111 to an IP address in the list of entries.
21113 @item @code{mail} (default: @code{"hostmaster"})
21114 An email address people can contact you at, as the owner of the zone. This
21115 is translated as @code{<mail>@@<origin>}.
21117 @item @code{serial} (default: @code{1})
21118 The serial number of the zone. As this is used to keep track of changes by
21119 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
21120 Always increment it when you make a change in your zone.
21122 @item @code{refresh} (default: @code{(* 2 24 3600)})
21123 The frequency at which slaves will do a zone transfer. This value is a number
21124 of seconds. It can be computed by multiplications or with
21125 @code{(string->duration)}.
21127 @item @code{retry} (default: @code{(* 15 60)})
21128 The period after which a slave will retry to contact its master when it fails
21129 to do so a first time.
21131 @item @code{expiry} (default: @code{(* 14 24 3600)})
21132 Default TTL of records. Existing records are considered correct for at most
21133 this amount of time. After this period, resolvers will invalidate their cache
21134 and check again that it still exists.
21136 @item @code{nx} (default: @code{3600})
21137 Default TTL of inexistant records. This delay is usually short because you want
21138 your new domains to reach everyone quickly.
21143 @deftp {Data Type} knot-remote-configuration
21144 Data type representing a remote configuration.
21145 This type has the following parameters:
21148 @item @code{id} (default: @code{""})
21149 An identifier for other configuration fields to refer to this remote. IDs must
21150 be unique and must not be empty.
21152 @item @code{address} (default: @code{'()})
21153 An ordered list of destination IP addresses. Addresses are tried in sequence.
21154 An optional port can be given with the @@ separator. For instance:
21155 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21157 @item @code{via} (default: @code{'()})
21158 An ordered list of source IP addresses. An empty list will have Knot choose
21159 an appropriate source IP. An optional port can be given with the @@ separator.
21160 The default is to choose at random.
21162 @item @code{key} (default: @code{#f})
21163 A reference to a key, that is a string containing the identifier of a key
21164 defined in a @code{knot-key-configuration} field.
21169 @deftp {Data Type} knot-keystore-configuration
21170 Data type representing a keystore to hold dnssec keys.
21171 This type has the following parameters:
21174 @item @code{id} (default: @code{""})
21175 The id of the keystore. It must not be empty.
21177 @item @code{backend} (default: @code{'pem})
21178 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21180 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21181 The configuration string of the backend. An example for the PKCS#11 is:
21182 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21183 For the pem backend, the string reprensents a path in the file system.
21188 @deftp {Data Type} knot-policy-configuration
21189 Data type representing a dnssec policy. Knot DNS is able to automatically
21190 sign your zones. It can either generate and manage your keys automatically or
21191 use keys that you generate.
21193 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21194 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21195 zone. In order to be trusted, the KSK needs to be present in the parent zone
21196 (usually a top-level domain). If your registrar supports dnssec, you will
21197 have to send them your KSK's hash so they can add a DS record in their zone.
21198 This is not automated and need to be done each time you change your KSK.
21200 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21201 easily and use weaker cryptographic functions (they use lower parameters) in
21202 order to sign records quickly, so they are changed often. The KSK however
21203 requires manual interaction with the registrar, so they are changed less often
21204 and use stronger parameters because they sign only one record.
21206 This type has the following parameters:
21209 @item @code{id} (default: @code{""})
21210 The id of the policy. It must not be empty.
21212 @item @code{keystore} (default: @code{"default"})
21213 A reference to a keystore, that is a string containing the identifier of a
21214 keystore defined in a @code{knot-keystore-configuration} field. The
21215 @code{"default"} identifier means the default keystore (a kasp database that
21216 was setup by this service).
21218 @item @code{manual?} (default: @code{#f})
21219 Whether the key management is manual or automatic.
21221 @item @code{single-type-signing?} (default: @code{#f})
21222 When @code{#t}, use the Single-Type Signing Scheme.
21224 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21225 An algorithm of signing keys and issued signatures.
21227 @item @code{ksk-size} (default: @code{256})
21228 The length of the KSK. Note that this value is correct for the default
21229 algorithm, but would be unsecure for other algorithms.
21231 @item @code{zsk-size} (default: @code{256})
21232 The length of the ZSK. Note that this value is correct for the default
21233 algorithm, but would be unsecure for other algorithms.
21235 @item @code{dnskey-ttl} (default: @code{'default})
21236 The TTL value for DNSKEY records added into zone apex. The special
21237 @code{'default} value means same as the zone SOA TTL.
21239 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21240 The period between ZSK publication and the next rollover initiation.
21242 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21243 An extra delay added for each key rollover step. This value should be high
21244 enough to cover propagation of data from the master server to all slaves.
21246 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21247 A validity period of newly issued signatures.
21249 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21250 A period how long before a signature expiration the signature will be refreshed.
21252 @item @code{nsec3?} (default: @code{#f})
21253 When @code{#t}, NSEC3 will be used instead of NSEC.
21255 @item @code{nsec3-iterations} (default: @code{5})
21256 The number of additional times the hashing is performed.
21258 @item @code{nsec3-salt-length} (default: @code{8})
21259 The length of a salt field in octets, which is appended to the original owner
21260 name before hashing.
21262 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21263 The validity period of newly issued salt field.
21268 @deftp {Data Type} knot-zone-configuration
21269 Data type representing a zone served by Knot.
21270 This type has the following parameters:
21273 @item @code{domain} (default: @code{""})
21274 The domain served by this configuration. It must not be empty.
21276 @item @code{file} (default: @code{""})
21277 The file where this zone is saved. This parameter is ignored by master zones.
21278 Empty means default location that depends on the domain name.
21280 @item @code{zone} (default: @code{(zone-file)})
21281 The content of the zone file. This parameter is ignored by slave zones. It
21282 must contain a zone-file record.
21284 @item @code{master} (default: @code{'()})
21285 A list of master remotes. When empty, this zone is a master. When set, this
21286 zone is a slave. This is a list of remotes identifiers.
21288 @item @code{ddns-master} (default: @code{#f})
21289 The main master. When empty, it defaults to the first master in the list of
21292 @item @code{notify} (default: @code{'()})
21293 A list of slave remote identifiers.
21295 @item @code{acl} (default: @code{'()})
21296 A list of acl identifiers.
21298 @item @code{semantic-checks?} (default: @code{#f})
21299 When set, this adds more semantic checks to the zone.
21301 @item @code{disable-any?} (default: @code{#f})
21302 When set, this forbids queries of the ANY type.
21304 @item @code{zonefile-sync} (default: @code{0})
21305 The delay between a modification in memory and on disk. 0 means immediate
21308 @item @code{zonefile-load} (default: @code{#f})
21309 The way the zone file contents are applied during zone load. Possible values
21313 @item @code{#f} for using the default value from Knot,
21314 @item @code{'none} for not using the zone file at all,
21315 @item @code{'difference} for computing the difference between already available
21316 contents and zone contents and applying it to the current zone contents,
21317 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21318 ignoring the SOA serial in the zone file, while the server takes care of it
21320 @item @code{'whole} for loading zone contents from the zone file.
21323 @item @code{journal-content} (default: @code{#f})
21324 The way the journal is used to store zone and its changes. Possible values
21325 are @code{'none} to not use it at all, @code{'changes} to store changes and
21326 @code{'all} to store contents. @code{#f} does not set this option, so the
21327 default value from Knot is used.
21329 @item @code{max-journal-usage} (default: @code{#f})
21330 The maximum size for the journal on disk. @code{#f} does not set this option,
21331 so the default value from Knot is used.
21333 @item @code{max-journal-depth} (default: @code{#f})
21334 The maximum size of the history. @code{#f} does not set this option, so the
21335 default value from Knot is used.
21337 @item @code{max-zone-size} (default: @code{#f})
21338 The maximum size of the zone file. This limit is enforced for incoming
21339 transfer and updates. @code{#f} does not set this option, so the default
21340 value from Knot is used.
21342 @item @code{dnssec-policy} (default: @code{#f})
21343 A reference to a @code{knot-policy-configuration} record, or the special
21344 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21347 @item @code{serial-policy} (default: @code{'increment})
21348 A policy between @code{'increment} and @code{'unixtime}.
21353 @deftp {Data Type} knot-configuration
21354 Data type representing the Knot configuration.
21355 This type has the following parameters:
21358 @item @code{knot} (default: @code{knot})
21361 @item @code{run-directory} (default: @code{"/var/run/knot"})
21362 The run directory. This directory will be used for pid file and sockets.
21364 @item @code{includes} (default: @code{'()})
21365 A list of strings or file-like objects denoting other files that must be
21366 included at the top of the configuration file.
21368 @cindex secrets, Knot service
21369 This can be used to manage secrets out-of-band. For example, secret
21370 keys may be stored in an out-of-band file not managed by Guix, and
21371 thus not visible in @file{/gnu/store}---e.g., you could store secret
21372 key configuration in @file{/etc/knot/secrets.conf} and add this file
21373 to the @code{includes} list.
21375 One can generate a secret tsig key (for nsupdate and zone transfers with the
21376 keymgr command from the knot package. Note that the package is not automatically
21377 installed by the service. The following example shows how to generate a new
21381 keymgr -t mysecret > /etc/knot/secrets.conf
21382 chmod 600 /etc/knot/secrets.conf
21385 Also note that the generated key will be named @var{mysecret}, so it is the
21386 name that needs to be used in the @var{key} field of the
21387 @code{knot-acl-configuration} record and in other places that need to refer
21390 It can also be used to add configuration not supported by this interface.
21392 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21393 An ip address on which to listen.
21395 @item @code{listen-v6} (default: @code{"::"})
21396 An ip address on which to listen.
21398 @item @code{listen-port} (default: @code{53})
21399 A port on which to listen.
21401 @item @code{keys} (default: @code{'()})
21402 The list of knot-key-configuration used by this configuration.
21404 @item @code{acls} (default: @code{'()})
21405 The list of knot-acl-configuration used by this configuration.
21407 @item @code{remotes} (default: @code{'()})
21408 The list of knot-remote-configuration used by this configuration.
21410 @item @code{zones} (default: @code{'()})
21411 The list of knot-zone-configuration used by this configuration.
21416 @subsubheading Knot Resolver Service
21418 @deffn {Scheme Variable} knot-resolver-service-type
21419 This this the type of the knot resolver service, whose value should be
21420 an @code{knot-resolver-configuration} object as in this example:
21423 (service knot-resolver-service-type
21424 (knot-resolver-configuration
21425 (kresd-config-file (plain-file "kresd.conf" "
21426 net.listen('192.168.0.1', 5353)
21427 user('knot-resolver', 'knot-resolver')
21428 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21429 cache.size = 100 * MB
21433 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21436 @deftp {Data Type} knot-resolver-configuration
21437 Data type representing the configuration of knot-resolver.
21440 @item @code{package} (default: @var{knot-resolver})
21441 Package object of the knot DNS resolver.
21443 @item @code{kresd-config-file} (default: %kresd.conf)
21444 File-like object of the kresd configuration file to use, by default it
21445 will listen on @code{127.0.0.1} and @code{::1}.
21447 @item @code{garbage-collection-interval} (default: 1000)
21448 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21454 @subsubheading Dnsmasq Service
21456 @deffn {Scheme Variable} dnsmasq-service-type
21457 This is the type of the dnsmasq service, whose value should be an
21458 @code{dnsmasq-configuration} object as in this example:
21461 (service dnsmasq-service-type
21462 (dnsmasq-configuration
21464 (servers '("192.168.1.1"))))
21468 @deftp {Data Type} dnsmasq-configuration
21469 Data type representing the configuration of dnsmasq.
21472 @item @code{package} (default: @var{dnsmasq})
21473 Package object of the dnsmasq server.
21475 @item @code{no-hosts?} (default: @code{#f})
21476 When true, don't read the hostnames in /etc/hosts.
21478 @item @code{port} (default: @code{53})
21479 The port to listen on. Setting this to zero completely disables DNS
21480 responses, leaving only DHCP and/or TFTP functions.
21482 @item @code{local-service?} (default: @code{#t})
21483 Accept DNS queries only from hosts whose address is on a local subnet,
21484 ie a subnet for which an interface exists on the server.
21486 @item @code{listen-addresses} (default: @code{'()})
21487 Listen on the given IP addresses.
21489 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21490 The file to read the IP address of the upstream nameservers from.
21492 @item @code{no-resolv?} (default: @code{#f})
21493 When true, don't read @var{resolv-file}.
21495 @item @code{servers} (default: @code{'()})
21496 Specify IP address of upstream servers directly.
21498 @item @code{cache-size} (default: @code{150})
21499 Set the size of dnsmasq's cache. Setting the cache size to zero
21502 @item @code{negative-cache?} (default: @code{#t})
21503 When false, disable negative caching.
21508 @subsubheading ddclient Service
21511 The ddclient service described below runs the ddclient daemon, which takes
21512 care of automatically updating DNS entries for service providers such as
21513 @uref{https://dyn.com/dns/, Dyn}.
21515 The following example show instantiates the service with its default
21519 (service ddclient-service-type)
21522 Note that ddclient needs to access credentials that are stored in a
21523 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
21524 @code{secret-file} below.) You are expected to create this file manually, in
21525 an ``out-of-band'' fashion (you @emph{could} make this file part of the
21526 service configuration, for instance by using @code{plain-file}, but it will be
21527 world-readable @i{via} @file{/gnu/store}.) See the examples in the
21528 @file{share/ddclient} directory of the @code{ddclient} package.
21530 @c %start of fragment
21532 Available @code{ddclient-configuration} fields are:
21534 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
21535 The ddclient package.
21539 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
21540 The period after which ddclient will retry to check IP and domain name.
21542 Defaults to @samp{300}.
21546 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
21547 Use syslog for the output.
21549 Defaults to @samp{#t}.
21553 @deftypevr {@code{ddclient-configuration} parameter} string mail
21556 Defaults to @samp{"root"}.
21560 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
21561 Mail failed update to user.
21563 Defaults to @samp{"root"}.
21567 @deftypevr {@code{ddclient-configuration} parameter} string pid
21568 The ddclient PID file.
21570 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
21574 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
21575 Enable SSL support.
21577 Defaults to @samp{#t}.
21581 @deftypevr {@code{ddclient-configuration} parameter} string user
21582 Specifies the user name or ID that is used when running ddclient
21585 Defaults to @samp{"ddclient"}.
21589 @deftypevr {@code{ddclient-configuration} parameter} string group
21590 Group of the user who will run the ddclient program.
21592 Defaults to @samp{"ddclient"}.
21596 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
21597 Secret file which will be appended to @file{ddclient.conf} file. This
21598 file contains credentials for use by ddclient. You are expected to
21599 create it manually.
21601 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
21605 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
21606 Extra options will be appended to @file{ddclient.conf} file.
21608 Defaults to @samp{()}.
21613 @c %end of fragment
21617 @subsection VPN Services
21618 @cindex VPN (virtual private network)
21619 @cindex virtual private network (VPN)
21621 The @code{(gnu services vpn)} module provides services related to
21622 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
21623 your machine to connect to a VPN, and a @emph{server} service for your machine
21624 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
21626 @deffn {Scheme Procedure} openvpn-client-service @
21627 [#:config (openvpn-client-configuration)]
21629 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
21632 @deffn {Scheme Procedure} openvpn-server-service @
21633 [#:config (openvpn-server-configuration)]
21635 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
21637 Both can be run simultaneously.
21640 @c %automatically generated documentation
21642 Available @code{openvpn-client-configuration} fields are:
21644 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
21645 The OpenVPN package.
21649 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
21650 The OpenVPN pid file.
21652 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21656 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
21657 The protocol (UDP or TCP) used to open a channel between clients and
21660 Defaults to @samp{udp}.
21664 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
21665 The device type used to represent the VPN connection.
21667 Defaults to @samp{tun}.
21671 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
21672 The certificate authority to check connections against.
21674 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21678 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
21679 The certificate of the machine the daemon is running on. It should be
21680 signed by the authority given in @code{ca}.
21682 Defaults to @samp{"/etc/openvpn/client.crt"}.
21686 @deftypevr {@code{openvpn-client-configuration} parameter} string key
21687 The key of the machine the daemon is running on. It must be the key whose
21688 certificate is @code{cert}.
21690 Defaults to @samp{"/etc/openvpn/client.key"}.
21694 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
21695 Whether to use the lzo compression algorithm.
21697 Defaults to @samp{#t}.
21701 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
21702 Don't re-read key files across SIGUSR1 or --ping-restart.
21704 Defaults to @samp{#t}.
21708 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
21709 Don't close and reopen TUN/TAP device or run up/down scripts across
21710 SIGUSR1 or --ping-restart restarts.
21712 Defaults to @samp{#t}.
21716 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
21719 Defaults to @samp{3}.
21723 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
21724 Add an additional layer of HMAC authentication on top of the TLS control
21725 channel to protect against DoS attacks.
21727 Defaults to @samp{#f}.
21731 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
21732 Whether to check the server certificate has server usage extension.
21734 Defaults to @samp{#t}.
21738 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
21739 Bind to a specific local port number.
21741 Defaults to @samp{#f}.
21745 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
21746 Retry resolving server address.
21748 Defaults to @samp{#t}.
21752 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
21753 A list of remote servers to connect to.
21755 Defaults to @samp{()}.
21757 Available @code{openvpn-remote-configuration} fields are:
21759 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
21762 Defaults to @samp{"my-server"}.
21766 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21767 Port number the server listens to.
21769 Defaults to @samp{1194}.
21774 @c %end of automatic openvpn-client documentation
21776 @c %automatically generated documentation
21778 Available @code{openvpn-server-configuration} fields are:
21780 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21781 The OpenVPN package.
21785 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21786 The OpenVPN pid file.
21788 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21792 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21793 The protocol (UDP or TCP) used to open a channel between clients and
21796 Defaults to @samp{udp}.
21800 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
21801 The device type used to represent the VPN connection.
21803 Defaults to @samp{tun}.
21807 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
21808 The certificate authority to check connections against.
21810 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21814 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
21815 The certificate of the machine the daemon is running on. It should be
21816 signed by the authority given in @code{ca}.
21818 Defaults to @samp{"/etc/openvpn/client.crt"}.
21822 @deftypevr {@code{openvpn-server-configuration} parameter} string key
21823 The key of the machine the daemon is running on. It must be the key whose
21824 certificate is @code{cert}.
21826 Defaults to @samp{"/etc/openvpn/client.key"}.
21830 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
21831 Whether to use the lzo compression algorithm.
21833 Defaults to @samp{#t}.
21837 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21838 Don't re-read key files across SIGUSR1 or --ping-restart.
21840 Defaults to @samp{#t}.
21844 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21845 Don't close and reopen TUN/TAP device or run up/down scripts across
21846 SIGUSR1 or --ping-restart restarts.
21848 Defaults to @samp{#t}.
21852 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21855 Defaults to @samp{3}.
21859 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21860 Add an additional layer of HMAC authentication on top of the TLS control
21861 channel to protect against DoS attacks.
21863 Defaults to @samp{#f}.
21867 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21868 Specifies the port number on which the server listens.
21870 Defaults to @samp{1194}.
21874 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21875 An ip and mask specifying the subnet inside the virtual network.
21877 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21881 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21882 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21884 Defaults to @samp{#f}.
21888 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21889 The Diffie-Hellman parameters file.
21891 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21895 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21896 The file that records client IPs.
21898 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21902 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21903 When true, the server will act as a gateway for its clients.
21905 Defaults to @samp{#f}.
21909 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21910 When true, clients are allowed to talk to each other inside the VPN.
21912 Defaults to @samp{#f}.
21916 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21917 Causes ping-like messages to be sent back and forth over the link so
21918 that each side knows when the other side has gone down. @code{keepalive}
21919 requires a pair. The first element is the period of the ping sending,
21920 and the second element is the timeout before considering the other side
21925 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21926 The maximum number of clients.
21928 Defaults to @samp{100}.
21932 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21933 The status file. This file shows a small report on current connection.
21934 It is truncated and rewritten every minute.
21936 Defaults to @samp{"/var/run/openvpn/status"}.
21940 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21941 The list of configuration for some clients.
21943 Defaults to @samp{()}.
21945 Available @code{openvpn-ccd-configuration} fields are:
21947 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21950 Defaults to @samp{"client"}.
21954 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21957 Defaults to @samp{#f}.
21961 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21964 Defaults to @samp{#f}.
21971 @c %end of automatic openvpn-server documentation
21974 @node Network File System
21975 @subsection Network File System
21978 The @code{(gnu services nfs)} module provides the following services,
21979 which are most commonly used in relation to mounting or exporting
21980 directory trees as @dfn{network file systems} (NFS).
21982 While it is possible to use the individual components that together make
21983 up a Network File System service, we recommended to configure an NFS
21984 server with the @code{nfs-service-type}.
21986 @subsubheading NFS Service
21987 @cindex NFS, server
21989 The NFS service takes care of setting up all NFS component services,
21990 kernel configuration file systems, and installs configuration files in
21991 the locations that NFS expects.
21993 @defvr {Scheme Variable} nfs-service-type
21994 A service type for a complete NFS server.
21997 @deftp {Data Type} nfs-configuration
21998 This data type represents the configuration of the NFS service and all
22001 It has the following parameters:
22003 @item @code{nfs-utils} (default: @code{nfs-utils})
22004 The nfs-utils package to use.
22006 @item @code{nfs-version} (default: @code{#f})
22007 If a string value is provided, the @command{rpc.nfsd} daemon will be
22008 limited to supporting the given version of the NFS protocol.
22010 @item @code{exports} (default: @code{'()})
22011 This is a list of directories the NFS server should export. Each entry
22012 is a list consisting of two elements: a directory name and a string
22013 containing all options. This is an example in which the directory
22014 @file{/export} is served to all NFS clients as a read-only share:
22020 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
22023 @item @code{rpcmountd-port} (default: @code{#f})
22024 The network port that the @command{rpc.mountd} daemon should use.
22026 @item @code{rpcstatd-port} (default: @code{#f})
22027 The network port that the @command{rpc.statd} daemon should use.
22029 @item @code{rpcbind} (default: @code{rpcbind})
22030 The rpcbind package to use.
22032 @item @code{idmap-domain} (default: @code{"localdomain"})
22033 The local NFSv4 domain name.
22035 @item @code{nfsd-port} (default: @code{2049})
22036 The network port that the @command{nfsd} daemon should use.
22038 @item @code{nfsd-threads} (default: @code{8})
22039 The number of threads used by the @command{nfsd} daemon.
22041 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22042 The directory where the pipefs file system is mounted.
22044 @item @code{debug} (default: @code{'()"})
22045 A list of subsystems for which debugging output should be enabled. This
22046 is a list of symbols. Any of these symbols are valid: @code{nfsd},
22047 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
22051 If you don't need a complete NFS service or prefer to build it yourself
22052 you can use the individual component services that are documented below.
22054 @subsubheading RPC Bind Service
22057 The RPC Bind service provides a facility to map program numbers into
22058 universal addresses.
22059 Many NFS related services use this facility. Hence it is automatically
22060 started when a dependent service starts.
22062 @defvr {Scheme Variable} rpcbind-service-type
22063 A service type for the RPC portmapper daemon.
22067 @deftp {Data Type} rpcbind-configuration
22068 Data type representing the configuration of the RPC Bind Service.
22069 This type has the following parameters:
22071 @item @code{rpcbind} (default: @code{rpcbind})
22072 The rpcbind package to use.
22074 @item @code{warm-start?} (default: @code{#t})
22075 If this parameter is @code{#t}, then the daemon will read a
22076 state file on startup thus reloading state information saved by a previous
22082 @subsubheading Pipefs Pseudo File System
22086 The pipefs file system is used to transfer NFS related data
22087 between the kernel and user space programs.
22089 @defvr {Scheme Variable} pipefs-service-type
22090 A service type for the pipefs pseudo file system.
22093 @deftp {Data Type} pipefs-configuration
22094 Data type representing the configuration of the pipefs pseudo file system service.
22095 This type has the following parameters:
22097 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22098 The directory to which the file system is to be attached.
22103 @subsubheading GSS Daemon Service
22106 @cindex global security system
22108 The @dfn{global security system} (GSS) daemon provides strong security for RPC
22110 Before exchanging RPC requests an RPC client must establish a security
22111 context. Typically this is done using the Kerberos command @command{kinit}
22112 or automatically at login time using PAM services (@pxref{Kerberos Services}).
22114 @defvr {Scheme Variable} gss-service-type
22115 A service type for the Global Security System (GSS) daemon.
22118 @deftp {Data Type} gss-configuration
22119 Data type representing the configuration of the GSS daemon service.
22120 This type has the following parameters:
22122 @item @code{nfs-utils} (default: @code{nfs-utils})
22123 The package in which the @command{rpc.gssd} command is to be found.
22125 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22126 The directory where the pipefs file system is mounted.
22132 @subsubheading IDMAP Daemon Service
22134 @cindex name mapper
22136 The idmap daemon service provides mapping between user IDs and user names.
22137 Typically it is required in order to access file systems mounted via NFSv4.
22139 @defvr {Scheme Variable} idmap-service-type
22140 A service type for the Identity Mapper (IDMAP) daemon.
22143 @deftp {Data Type} idmap-configuration
22144 Data type representing the configuration of the IDMAP daemon service.
22145 This type has the following parameters:
22147 @item @code{nfs-utils} (default: @code{nfs-utils})
22148 The package in which the @command{rpc.idmapd} command is to be found.
22150 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22151 The directory where the pipefs file system is mounted.
22153 @item @code{domain} (default: @code{#f})
22154 The local NFSv4 domain name.
22155 This must be a string or @code{#f}.
22156 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
22158 @item @code{verbosity} (default: @code{0})
22159 The verbosity level of the daemon.
22164 @node Continuous Integration
22165 @subsection Continuous Integration
22167 @cindex continuous integration
22168 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
22169 continuous integration tool for Guix. It can be used both for development and
22170 for providing substitutes to others (@pxref{Substitutes}).
22172 The @code{(gnu services cuirass)} module provides the following service.
22174 @defvr {Scheme Procedure} cuirass-service-type
22175 The type of the Cuirass service. Its value must be a
22176 @code{cuirass-configuration} object, as described below.
22179 To add build jobs, you have to set the @code{specifications} field of the
22180 configuration. Here is an example of a service that polls the Guix repository
22181 and builds the packages from a manifest. Some of the packages are defined in
22182 the @code{"custom-packages"} input, which is the equivalent of
22183 @code{GUIX_PACKAGE_PATH}.
22186 (define %cuirass-specs
22188 '((#:name . "my-manifest")
22189 (#:load-path-inputs . ("guix"))
22190 (#:package-path-inputs . ("custom-packages"))
22191 (#:proc-input . "guix")
22192 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
22193 (#:proc . cuirass-jobs)
22194 (#:proc-args . ((subset . "manifests")
22195 (systems . ("x86_64-linux"))
22196 (manifests . (("config" . "guix/manifest.scm")))))
22197 (#:inputs . (((#:name . "guix")
22198 (#:url . "git://git.savannah.gnu.org/guix.git")
22199 (#:load-path . ".")
22200 (#:branch . "master")
22201 (#:no-compile? . #t))
22202 ((#:name . "config")
22203 (#:url . "https://git.example.org/config.git")
22204 (#:load-path . ".")
22205 (#:branch . "master")
22206 (#:no-compile? . #t))
22207 ((#:name . "custom-packages")
22208 (#:url . "https://git.example.org/custom-packages.git")
22209 (#:load-path . ".")
22210 (#:branch . "master")
22211 (#:no-compile? . #t)))))))
22213 (service cuirass-service-type
22214 (cuirass-configuration
22215 (specifications %cuirass-specs)))
22218 While information related to build jobs is located directly in the
22219 specifications, global settings for the @command{cuirass} process are
22220 accessible in other @code{cuirass-configuration} fields.
22222 @deftp {Data Type} cuirass-configuration
22223 Data type representing the configuration of Cuirass.
22226 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22227 Location of the log file.
22229 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22230 Location of the log file used by the web interface.
22232 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22233 Location of the repository cache.
22235 @item @code{user} (default: @code{"cuirass"})
22236 Owner of the @code{cuirass} process.
22238 @item @code{group} (default: @code{"cuirass"})
22239 Owner's group of the @code{cuirass} process.
22241 @item @code{interval} (default: @code{60})
22242 Number of seconds between the poll of the repositories followed by the
22245 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22246 Location of sqlite database which contains the build results and previously
22247 added specifications.
22249 @item @code{ttl} (default: @code{(* 30 24 3600)})
22250 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22251 are registered for build results. This means that build results are protected
22252 from garbage collection for at least @var{ttl} seconds.
22254 @item @code{port} (default: @code{8081})
22255 Port number used by the HTTP server.
22257 @item @code{host} (default: @code{"localhost"})
22258 Listen on the network interface for @var{host}. The default is to
22259 accept connections from localhost.
22261 @item @code{specifications} (default: @code{#~'()})
22262 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22263 where a specification is an association list
22264 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22265 keys are keywords (@code{#:keyword-example}) as shown in the example
22268 @item @code{use-substitutes?} (default: @code{#f})
22269 This allows using substitutes to avoid building every dependencies of a job
22272 @item @code{one-shot?} (default: @code{#f})
22273 Only evaluate specifications and build derivations once.
22275 @item @code{fallback?} (default: @code{#f})
22276 When substituting a pre-built binary fails, fall back to building
22279 @item @code{cuirass} (default: @code{cuirass})
22280 The Cuirass package to use.
22284 @node Power Management Services
22285 @subsection Power Management Services
22288 @cindex power management with TLP
22289 @subsubheading TLP daemon
22291 The @code{(gnu services pm)} module provides a Guix service definition
22292 for the Linux power management tool TLP.
22294 TLP enables various powersaving modes in userspace and kernel.
22295 Contrary to @code{upower-service}, it is not a passive,
22296 monitoring tool, as it will apply custom settings each time a new power
22297 source is detected. More information can be found at
22298 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22300 @deffn {Scheme Variable} tlp-service-type
22301 The service type for the TLP tool. Its value should be a valid
22302 TLP configuration (see below). To use the default settings, simply
22305 (service tlp-service-type)
22309 By default TLP does not need much configuration but most TLP parameters
22310 can be tweaked using @code{tlp-configuration}.
22312 Each parameter definition is preceded by its type; for example,
22313 @samp{boolean foo} indicates that the @code{foo} parameter
22314 should be specified as a boolean. Types starting with
22315 @code{maybe-} denote parameters that won't show up in TLP config file
22316 when their value is @code{'disabled}.
22318 @c The following documentation was initially generated by
22319 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22320 @c documentation is better, so we shouldn't hesitate to edit below as
22321 @c needed. However if the change you want to make to this documentation
22322 @c can be done in an automated way, it's probably easier to change
22323 @c (generate-documentation) than to make it below and have to deal with
22324 @c the churn as TLP updates.
22326 Available @code{tlp-configuration} fields are:
22328 @deftypevr {@code{tlp-configuration} parameter} package tlp
22333 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22334 Set to true if you wish to enable TLP.
22336 Defaults to @samp{#t}.
22340 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22341 Default mode when no power supply can be detected. Alternatives are AC
22344 Defaults to @samp{"AC"}.
22348 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22349 Number of seconds Linux kernel has to wait after the disk goes idle,
22350 before syncing on AC.
22352 Defaults to @samp{0}.
22356 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22357 Same as @code{disk-idle-ac} but on BAT mode.
22359 Defaults to @samp{2}.
22363 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22364 Dirty pages flushing periodicity, expressed in seconds.
22366 Defaults to @samp{15}.
22370 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22371 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22373 Defaults to @samp{60}.
22377 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22378 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22379 alternatives are powersave and performance. With acpi-cpufreq driver,
22380 alternatives are ondemand, powersave, performance and conservative.
22382 Defaults to @samp{disabled}.
22386 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22387 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22389 Defaults to @samp{disabled}.
22393 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22394 Set the min available frequency for the scaling governor on AC.
22396 Defaults to @samp{disabled}.
22400 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22401 Set the max available frequency for the scaling governor on AC.
22403 Defaults to @samp{disabled}.
22407 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22408 Set the min available frequency for the scaling governor on BAT.
22410 Defaults to @samp{disabled}.
22414 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22415 Set the max available frequency for the scaling governor on BAT.
22417 Defaults to @samp{disabled}.
22421 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22422 Limit the min P-state to control the power dissipation of the CPU, in AC
22423 mode. Values are stated as a percentage of the available performance.
22425 Defaults to @samp{disabled}.
22429 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22430 Limit the max P-state to control the power dissipation of the CPU, in AC
22431 mode. Values are stated as a percentage of the available performance.
22433 Defaults to @samp{disabled}.
22437 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22438 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22440 Defaults to @samp{disabled}.
22444 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22445 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22447 Defaults to @samp{disabled}.
22451 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22452 Enable CPU turbo boost feature on AC mode.
22454 Defaults to @samp{disabled}.
22458 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22459 Same as @code{cpu-boost-on-ac?} on BAT mode.
22461 Defaults to @samp{disabled}.
22465 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22466 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22467 used under light load conditions.
22469 Defaults to @samp{#f}.
22473 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22474 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22476 Defaults to @samp{#t}.
22480 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22481 Enable Linux kernel NMI watchdog.
22483 Defaults to @samp{#f}.
22487 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22488 For Linux kernels with PHC patch applied, change CPU voltages. An
22489 example value would be @samp{"F:V F:V F:V F:V"}.
22491 Defaults to @samp{disabled}.
22495 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
22496 Set CPU performance versus energy saving policy on AC. Alternatives are
22497 performance, normal, powersave.
22499 Defaults to @samp{"performance"}.
22503 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
22504 Same as @code{energy-perf-policy-ac} but on BAT mode.
22506 Defaults to @samp{"powersave"}.
22510 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
22515 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
22516 Hard disk advanced power management level.
22520 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
22521 Same as @code{disk-apm-bat} but on BAT mode.
22525 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
22526 Hard disk spin down timeout. One value has to be specified for each
22527 declared hard disk.
22529 Defaults to @samp{disabled}.
22533 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
22534 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
22536 Defaults to @samp{disabled}.
22540 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
22541 Select IO scheduler for disk devices. One value has to be specified for
22542 each declared hard disk. Example alternatives are cfq, deadline and
22545 Defaults to @samp{disabled}.
22549 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
22550 SATA aggressive link power management (ALPM) level. Alternatives are
22551 min_power, medium_power, max_performance.
22553 Defaults to @samp{"max_performance"}.
22557 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
22558 Same as @code{sata-linkpwr-ac} but on BAT mode.
22560 Defaults to @samp{"min_power"}.
22564 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
22565 Exclude specified SATA host devices for link power management.
22567 Defaults to @samp{disabled}.
22571 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
22572 Enable Runtime Power Management for AHCI controller and disks on AC
22575 Defaults to @samp{disabled}.
22579 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
22580 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
22582 Defaults to @samp{disabled}.
22586 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
22587 Seconds of inactivity before disk is suspended.
22589 Defaults to @samp{15}.
22593 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
22594 PCI Express Active State Power Management level. Alternatives are
22595 default, performance, powersave.
22597 Defaults to @samp{"performance"}.
22601 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
22602 Same as @code{pcie-aspm-ac} but on BAT mode.
22604 Defaults to @samp{"powersave"}.
22608 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
22609 Radeon graphics clock speed level. Alternatives are low, mid, high,
22612 Defaults to @samp{"high"}.
22616 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
22617 Same as @code{radeon-power-ac} but on BAT mode.
22619 Defaults to @samp{"low"}.
22623 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
22624 Radeon dynamic power management method (DPM). Alternatives are battery,
22627 Defaults to @samp{"performance"}.
22631 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
22632 Same as @code{radeon-dpm-state-ac} but on BAT mode.
22634 Defaults to @samp{"battery"}.
22638 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
22639 Radeon DPM performance level. Alternatives are auto, low, high.
22641 Defaults to @samp{"auto"}.
22645 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
22646 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
22648 Defaults to @samp{"auto"}.
22652 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
22653 Wifi power saving mode.
22655 Defaults to @samp{#f}.
22659 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
22660 Same as @code{wifi-power-ac?} but on BAT mode.
22662 Defaults to @samp{#t}.
22666 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
22667 Disable wake on LAN.
22669 Defaults to @samp{#t}.
22673 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
22674 Timeout duration in seconds before activating audio power saving on
22675 Intel HDA and AC97 devices. A value of 0 disables power saving.
22677 Defaults to @samp{0}.
22681 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
22682 Same as @code{sound-powersave-ac} but on BAT mode.
22684 Defaults to @samp{1}.
22688 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
22689 Disable controller in powersaving mode on Intel HDA devices.
22691 Defaults to @samp{#t}.
22695 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
22696 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
22697 powered on again by releasing (and reinserting) the eject lever or by
22698 pressing the disc eject button on newer models.
22700 Defaults to @samp{#f}.
22704 @deftypevr {@code{tlp-configuration} parameter} string bay-device
22705 Name of the optical drive device to power off.
22707 Defaults to @samp{"sr0"}.
22711 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
22712 Runtime Power Management for PCI(e) bus devices. Alternatives are on
22715 Defaults to @samp{"on"}.
22719 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
22720 Same as @code{runtime-pm-ac} but on BAT mode.
22722 Defaults to @samp{"auto"}.
22726 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
22727 Runtime Power Management for all PCI(e) bus devices, except blacklisted
22730 Defaults to @samp{#t}.
22734 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
22735 Exclude specified PCI(e) device addresses from Runtime Power Management.
22737 Defaults to @samp{disabled}.
22741 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
22742 Exclude PCI(e) devices assigned to the specified drivers from Runtime
22747 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
22748 Enable USB autosuspend feature.
22750 Defaults to @samp{#t}.
22754 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
22755 Exclude specified devices from USB autosuspend.
22757 Defaults to @samp{disabled}.
22761 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
22762 Exclude WWAN devices from USB autosuspend.
22764 Defaults to @samp{#t}.
22768 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
22769 Include specified devices into USB autosuspend, even if they are already
22770 excluded by the driver or via @code{usb-blacklist-wwan?}.
22772 Defaults to @samp{disabled}.
22776 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
22777 Enable USB autosuspend before shutdown.
22779 Defaults to @samp{disabled}.
22783 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
22784 Restore radio device state (bluetooth, wifi, wwan) from previous
22785 shutdown on system startup.
22787 Defaults to @samp{#f}.
22792 @cindex CPU frequency scaling with thermald
22793 @subsubheading Thermald daemon
22795 The @code{(gnu services pm)} module provides an interface to
22796 thermald, a CPU frequency scaling service which helps prevent overheating.
22798 @defvr {Scheme Variable} thermald-service-type
22799 This is the service type for
22800 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
22801 Thermal Daemon, which is responsible for controlling the thermal state
22802 of processors and preventing overheating.
22805 @deftp {Data Type} thermald-configuration
22806 Data type representing the configuration of @code{thermald-service-type}.
22809 @item @code{ignore-cpuid-check?} (default: @code{#f})
22810 Ignore cpuid check for supported CPU models.
22812 @item @code{thermald} (default: @var{thermald})
22813 Package object of thermald.
22818 @node Audio Services
22819 @subsection Audio Services
22821 The @code{(gnu services audio)} module provides a service to start MPD
22822 (the Music Player Daemon).
22825 @subsubheading Music Player Daemon
22827 The Music Player Daemon (MPD) is a service that can play music while
22828 being controlled from the local machine or over the network by a variety
22831 The following example shows how one might run @code{mpd} as user
22832 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
22835 (service mpd-service-type
22841 @defvr {Scheme Variable} mpd-service-type
22842 The service type for @command{mpd}
22845 @deftp {Data Type} mpd-configuration
22846 Data type representing the configuration of @command{mpd}.
22849 @item @code{user} (default: @code{"mpd"})
22850 The user to run mpd as.
22852 @item @code{music-dir} (default: @code{"~/Music"})
22853 The directory to scan for music files.
22855 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
22856 The directory to store playlists.
22858 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
22859 The location of the music database.
22861 @item @code{state-file} (default: @code{"~/.mpd/state"})
22862 The location of the file that stores current MPD's state.
22864 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
22865 The location of the sticker database.
22867 @item @code{port} (default: @code{"6600"})
22868 The port to run mpd on.
22870 @item @code{address} (default: @code{"any"})
22871 The address that mpd will bind to. To use a Unix domain socket,
22872 an absolute path can be specified here.
22874 @item @code{outputs} (default: @code{"(list (mpd-output))"})
22875 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
22880 @deftp {Data Type} mpd-output
22881 Data type representing an @command{mpd} audio output.
22884 @item @code{name} (default: @code{"MPD"})
22885 The name of the audio output.
22887 @item @code{type} (default: @code{"pulse"})
22888 The type of audio output.
22890 @item @code{enabled?} (default: @code{#t})
22891 Specifies whether this audio output is enabled when MPD is started. By
22892 default, all audio outputs are enabled. This is just the default
22893 setting when there is no state file; with a state file, the previous
22896 @item @code{tags?} (default: @code{#t})
22897 If set to @code{#f}, then MPD will not send tags to this output. This
22898 is only useful for output plugins that can receive tags, for example the
22899 @code{httpd} output plugin.
22901 @item @code{always-on?} (default: @code{#f})
22902 If set to @code{#t}, then MPD attempts to keep this audio output always
22903 open. This may be useful for streaming servers, when you don’t want to
22904 disconnect all listeners even when playback is accidentally stopped.
22906 @item @code{mixer-type}
22907 This field accepts a symbol that specifies which mixer should be used
22908 for this audio output: the @code{hardware} mixer, the @code{software}
22909 mixer, the @code{null} mixer (allows setting the volume, but with no
22910 effect; this can be used as a trick to implement an external mixer
22911 External Mixer) or no mixer (@code{none}).
22913 @item @code{extra-options} (default: @code{'()"})
22914 An association list of option symbols to string values to be appended to
22915 the audio output configuration.
22920 The following example shows a configuration of @code{mpd} that provides
22921 an HTTP audio streaming output.
22924 (service mpd-service-type
22932 `((encoder . "vorbis")
22933 (port . "8080"))))))))
22937 @node Virtualization Services
22938 @subsection Virtualization services
22940 The @code{(gnu services virtualization)} module provides services for
22941 the libvirt and virtlog daemons, as well as other virtualization-related
22944 @subsubheading Libvirt daemon
22945 @code{libvirtd} is the server side daemon component of the libvirt
22946 virtualization management system. This daemon runs on host servers
22947 and performs required management tasks for virtualized guests.
22949 @deffn {Scheme Variable} libvirt-service-type
22950 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
22951 Its value must be a @code{libvirt-configuration}.
22954 (service libvirt-service-type
22955 (libvirt-configuration
22956 (unix-sock-group "libvirt")
22957 (tls-port "16555")))
22961 @c Auto-generated with (generate-libvirt-documentation)
22962 Available @code{libvirt-configuration} fields are:
22964 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
22969 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
22970 Flag listening for secure TLS connections on the public TCP/IP port.
22971 must set @code{listen} for this to have any effect.
22973 It is necessary to setup a CA and issue server certificates before using
22976 Defaults to @samp{#t}.
22980 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22981 Listen for unencrypted TCP connections on the public TCP/IP port. must
22982 set @code{listen} for this to have any effect.
22984 Using the TCP socket requires SASL authentication by default. Only SASL
22985 mechanisms which support data encryption are allowed. This is
22986 DIGEST_MD5 and GSSAPI (Kerberos5)
22988 Defaults to @samp{#f}.
22992 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
22993 Port for accepting secure TLS connections This can be a port number, or
22996 Defaults to @samp{"16514"}.
23000 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
23001 Port for accepting insecure TCP connections This can be a port number,
23004 Defaults to @samp{"16509"}.
23008 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
23009 IP address or hostname used for client connections.
23011 Defaults to @samp{"0.0.0.0"}.
23015 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
23016 Flag toggling mDNS advertisement of the libvirt service.
23018 Alternatively can disable for all services on a host by stopping the
23021 Defaults to @samp{#f}.
23025 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
23026 Default mDNS advertisement name. This must be unique on the immediate
23029 Defaults to @samp{"Virtualization Host <hostname>"}.
23033 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
23034 UNIX domain socket group ownership. This can be used to allow a
23035 'trusted' set of users access to management capabilities without
23038 Defaults to @samp{"root"}.
23042 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
23043 UNIX socket permissions for the R/O socket. This is used for monitoring
23046 Defaults to @samp{"0777"}.
23050 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
23051 UNIX socket permissions for the R/W socket. Default allows only root.
23052 If PolicyKit is enabled on the socket, the default will change to allow
23053 everyone (eg, 0777)
23055 Defaults to @samp{"0770"}.
23059 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
23060 UNIX socket permissions for the admin socket. Default allows only owner
23061 (root), do not change it unless you are sure to whom you are exposing
23064 Defaults to @samp{"0777"}.
23068 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
23069 The directory in which sockets will be found/created.
23071 Defaults to @samp{"/var/run/libvirt"}.
23075 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
23076 Authentication scheme for UNIX read-only sockets. By default socket
23077 permissions allow anyone to connect
23079 Defaults to @samp{"polkit"}.
23083 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
23084 Authentication scheme for UNIX read-write sockets. By default socket
23085 permissions only allow root. If PolicyKit support was compiled into
23086 libvirt, the default will be to use 'polkit' auth.
23088 Defaults to @samp{"polkit"}.
23092 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
23093 Authentication scheme for TCP sockets. If you don't enable SASL, then
23094 all TCP traffic is cleartext. Don't do this outside of a dev/test
23097 Defaults to @samp{"sasl"}.
23101 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
23102 Authentication scheme for TLS sockets. TLS sockets already have
23103 encryption provided by the TLS layer, and limited authentication is done
23106 It is possible to make use of any SASL authentication mechanism as well,
23107 by using 'sasl' for this option
23109 Defaults to @samp{"none"}.
23113 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
23114 API access control scheme.
23116 By default an authenticated user is allowed access to all APIs. Access
23117 drivers can place restrictions on this.
23119 Defaults to @samp{()}.
23123 @deftypevr {@code{libvirt-configuration} parameter} string key-file
23124 Server key file path. If set to an empty string, then no private key is
23127 Defaults to @samp{""}.
23131 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
23132 Server key file path. If set to an empty string, then no certificate is
23135 Defaults to @samp{""}.
23139 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
23140 Server key file path. If set to an empty string, then no CA certificate
23143 Defaults to @samp{""}.
23147 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
23148 Certificate revocation list path. If set to an empty string, then no
23151 Defaults to @samp{""}.
23155 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
23156 Disable verification of our own server certificates.
23158 When libvirtd starts it performs some sanity checks against its own
23161 Defaults to @samp{#f}.
23165 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
23166 Disable verification of client certificates.
23168 Client certificate verification is the primary authentication mechanism.
23169 Any client which does not present a certificate signed by the CA will be
23172 Defaults to @samp{#f}.
23176 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
23177 Whitelist of allowed x509 Distinguished Name.
23179 Defaults to @samp{()}.
23183 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
23184 Whitelist of allowed SASL usernames. The format for username depends on
23185 the SASL authentication mechanism.
23187 Defaults to @samp{()}.
23191 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
23192 Override the compile time default TLS priority string. The default is
23193 usually "NORMAL" unless overridden at build time. Only set this is it
23194 is desired for libvirt to deviate from the global default settings.
23196 Defaults to @samp{"NORMAL"}.
23200 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
23201 Maximum number of concurrent client connections to allow over all
23204 Defaults to @samp{5000}.
23208 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
23209 Maximum length of queue of connections waiting to be accepted by the
23210 daemon. Note, that some protocols supporting retransmission may obey
23211 this so that a later reattempt at connection succeeds.
23213 Defaults to @samp{1000}.
23217 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
23218 Maximum length of queue of accepted but not yet authenticated clients.
23219 Set this to zero to turn this feature off
23221 Defaults to @samp{20}.
23225 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23226 Number of workers to start up initially.
23228 Defaults to @samp{5}.
23232 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23233 Maximum number of worker threads.
23235 If the number of active clients exceeds @code{min-workers}, then more
23236 threads are spawned, up to max_workers limit. Typically you'd want
23237 max_workers to equal maximum number of clients allowed.
23239 Defaults to @samp{20}.
23243 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23244 Number of priority workers. If all workers from above pool are stuck,
23245 some calls marked as high priority (notably domainDestroy) can be
23246 executed in this pool.
23248 Defaults to @samp{5}.
23252 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23253 Total global limit on concurrent RPC calls.
23255 Defaults to @samp{20}.
23259 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23260 Limit on concurrent requests from a single client connection. To avoid
23261 one client monopolizing the server this should be a small fraction of
23262 the global max_requests and max_workers parameter.
23264 Defaults to @samp{5}.
23268 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23269 Same as @code{min-workers} but for the admin interface.
23271 Defaults to @samp{1}.
23275 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23276 Same as @code{max-workers} but for the admin interface.
23278 Defaults to @samp{5}.
23282 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23283 Same as @code{max-clients} but for the admin interface.
23285 Defaults to @samp{5}.
23289 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23290 Same as @code{max-queued-clients} but for the admin interface.
23292 Defaults to @samp{5}.
23296 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23297 Same as @code{max-client-requests} but for the admin interface.
23299 Defaults to @samp{5}.
23303 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23304 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23306 Defaults to @samp{3}.
23310 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23313 A filter allows to select a different logging level for a given category
23314 of logs The format for a filter is one of:
23325 where @code{name} is a string which is matched against the category
23326 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23327 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23328 be a substring of the full category name, in order to match multiple
23329 similar categories), the optional "+" prefix tells libvirt to log stack
23330 trace for each message matching name, and @code{x} is the minimal level
23331 where matching messages should be logged:
23348 Multiple filters can be defined in a single filters statement, they just
23349 need to be separated by spaces.
23351 Defaults to @samp{"3:remote 4:event"}.
23355 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23358 An output is one of the places to save logging information. The format
23359 for an output can be:
23363 output goes to stderr
23365 @item x:syslog:name
23366 use syslog for the output and use the given name as the ident
23368 @item x:file:file_path
23369 output to a file, with the given filepath
23372 output to journald logging system
23376 In all case the x prefix is the minimal level, acting as a filter
23393 Multiple outputs can be defined, they just need to be separated by
23396 Defaults to @samp{"3:stderr"}.
23400 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23401 Allows usage of the auditing subsystem to be altered
23405 0: disable all auditing
23408 1: enable auditing, only if enabled on host
23411 2: enable auditing, and exit if disabled on host.
23415 Defaults to @samp{1}.
23419 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23420 Send audit messages via libvirt logging infrastructure.
23422 Defaults to @samp{#f}.
23426 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23427 Host UUID. UUID must not have all digits be the same.
23429 Defaults to @samp{""}.
23433 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23434 Source to read host UUID.
23438 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23441 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23445 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23448 Defaults to @samp{"smbios"}.
23452 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23453 A keepalive message is sent to a client after @code{keepalive_interval}
23454 seconds of inactivity to check if the client is still responding. If
23455 set to -1, libvirtd will never send keepalive requests; however clients
23456 can still send them and the daemon will send responses.
23458 Defaults to @samp{5}.
23462 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23463 Maximum number of keepalive messages that are allowed to be sent to the
23464 client without getting any response before the connection is considered
23467 In other words, the connection is automatically closed approximately
23468 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23469 the last message received from the client. When @code{keepalive-count}
23470 is set to 0, connections will be automatically closed after
23471 @code{keepalive-interval} seconds of inactivity without sending any
23472 keepalive messages.
23474 Defaults to @samp{5}.
23478 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23479 Same as above but for admin interface.
23481 Defaults to @samp{5}.
23485 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23486 Same as above but for admin interface.
23488 Defaults to @samp{5}.
23492 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
23493 Timeout for Open vSwitch calls.
23495 The @code{ovs-vsctl} utility is used for the configuration and its
23496 timeout option is set by default to 5 seconds to avoid potential
23497 infinite waits blocking libvirt.
23499 Defaults to @samp{5}.
23503 @c %end of autogenerated docs
23505 @subsubheading Virtlog daemon
23506 The virtlogd service is a server side daemon component of libvirt that is
23507 used to manage logs from virtual machine consoles.
23509 This daemon is not used directly by libvirt client applications, rather it
23510 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
23511 standalone daemon, the main @code{libvirtd} daemon can be restarted without
23512 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
23513 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
23515 @deffn {Scheme Variable} virtlog-service-type
23516 This is the type of the virtlog daemon.
23517 Its value must be a @code{virtlog-configuration}.
23520 (service virtlog-service-type
23521 (virtlog-configuration
23522 (max-clients 1000)))
23526 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
23527 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23529 Defaults to @samp{3}.
23533 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
23536 A filter allows to select a different logging level for a given category
23537 of logs The format for a filter is one of:
23548 where @code{name} is a string which is matched against the category
23549 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23550 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23551 be a substring of the full category name, in order to match multiple
23552 similar categories), the optional "+" prefix tells libvirt to log stack
23553 trace for each message matching name, and @code{x} is the minimal level
23554 where matching messages should be logged:
23571 Multiple filters can be defined in a single filters statement, they just
23572 need to be separated by spaces.
23574 Defaults to @samp{"3:remote 4:event"}.
23578 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
23581 An output is one of the places to save logging information The format
23582 for an output can be:
23586 output goes to stderr
23588 @item x:syslog:name
23589 use syslog for the output and use the given name as the ident
23591 @item x:file:file_path
23592 output to a file, with the given filepath
23595 output to journald logging system
23599 In all case the x prefix is the minimal level, acting as a filter
23616 Multiple outputs can be defined, they just need to be separated by
23619 Defaults to @samp{"3:stderr"}.
23623 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
23624 Maximum number of concurrent client connections to allow over all
23627 Defaults to @samp{1024}.
23631 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
23632 Maximum file size before rolling over.
23634 Defaults to @samp{2MB}
23638 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
23639 Maximum number of backup files to keep.
23641 Defaults to @samp{3}
23645 @subsubheading Transparent Emulation with QEMU
23648 @cindex @code{binfmt_misc}
23649 @code{qemu-binfmt-service-type} provides support for transparent
23650 emulation of program binaries built for different architectures---e.g.,
23651 it allows you to transparently execute an ARMv7 program on an x86_64
23652 machine. It achieves this by combining the @uref{https://www.qemu.org,
23653 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
23655 @defvr {Scheme Variable} qemu-binfmt-service-type
23656 This is the type of the QEMU/binfmt service for transparent emulation.
23657 Its value must be a @code{qemu-binfmt-configuration} object, which
23658 specifies the QEMU package to use as well as the architecture we want to
23662 (service qemu-binfmt-service-type
23663 (qemu-binfmt-configuration
23664 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
23667 In this example, we enable transparent emulation for the ARM and aarch64
23668 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
23669 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
23670 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
23673 @deftp {Data Type} qemu-binfmt-configuration
23674 This is the configuration for the @code{qemu-binfmt} service.
23677 @item @code{platforms} (default: @code{'()})
23678 The list of emulated QEMU platforms. Each item must be a @dfn{platform
23679 object} as returned by @code{lookup-qemu-platforms} (see below).
23681 @item @code{guix-support?} (default: @code{#f})
23682 When it is true, QEMU and all its dependencies are added to the build
23683 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
23684 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
23685 handlers to be used within the build environment, which in turn means
23686 that you can transparently build programs for another architecture.
23688 For example, let's suppose you're on an x86_64 machine and you have this
23692 (service qemu-binfmt-service-type
23693 (qemu-binfmt-configuration
23694 (platforms (lookup-qemu-platforms "arm"))
23695 (guix-support? #t)))
23701 guix build -s armhf-linux inkscape
23705 and it will build Inkscape for ARMv7 @emph{as if it were a native
23706 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
23707 if you'd like to test a package build for an architecture you don't have
23710 @item @code{qemu} (default: @code{qemu})
23711 The QEMU package to use.
23715 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
23716 Return the list of QEMU platform objects corresponding to
23717 @var{platforms}@dots{}. @var{platforms} must be a list of strings
23718 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
23719 @code{"mips64el"}, and so on.
23722 @deffn {Scheme Procedure} qemu-platform? @var{obj}
23723 Return true if @var{obj} is a platform object.
23726 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
23727 Return the name of @var{platform}---a string such as @code{"arm"}.
23730 @node Version Control Services
23731 @subsection Version Control Services
23733 The @code{(gnu services version-control)} module provides a service to
23734 allow remote access to local Git repositories. There are three options:
23735 the @code{git-daemon-service}, which provides access to repositories via
23736 the @code{git://} unsecured TCP-based protocol, extending the
23737 @code{nginx} web server to proxy some requests to
23738 @code{git-http-backend}, or providing a web interface with
23739 @code{cgit-service-type}.
23741 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
23743 Return a service that runs @command{git daemon}, a simple TCP server to
23744 expose repositories over the Git protocol for anonymous access.
23746 The optional @var{config} argument should be a
23747 @code{<git-daemon-configuration>} object, by default it allows read-only
23748 access to exported@footnote{By creating the magic file
23749 "git-daemon-export-ok" in the repository directory.} repositories under
23754 @deftp {Data Type} git-daemon-configuration
23755 Data type representing the configuration for @code{git-daemon-service}.
23758 @item @code{package} (default: @var{git})
23759 Package object of the Git distributed version control system.
23761 @item @code{export-all?} (default: @var{#f})
23762 Whether to allow access for all Git repositories, even if they do not
23763 have the @file{git-daemon-export-ok} file.
23765 @item @code{base-path} (default: @file{/srv/git})
23766 Whether to remap all the path requests as relative to the given path.
23767 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
23768 then if you later try to pull @code{git://example.com/hello.git}, git
23769 daemon will interpret the path as @code{/srv/git/hello.git}.
23771 @item @code{user-path} (default: @var{#f})
23772 Whether to allow @code{~user} notation to be used in requests. When
23773 specified with empty string, requests to @code{git://host/~alice/foo} is
23774 taken as a request to access @code{foo} repository in the home directory
23775 of user @code{alice}. If @var{(user-path "path")} is specified, the
23776 same request is taken as a request to access @code{path/foo} repository
23777 in the home directory of user @code{alice}.
23779 @item @code{listen} (default: @var{'()})
23780 Whether to listen on specific IP addresses or hostnames, defaults to
23783 @item @code{port} (default: @var{#f})
23784 Whether to listen on an alternative port, which defaults to 9418.
23786 @item @code{whitelist} (default: @var{'()})
23787 If not empty, only allow access to this list of directories.
23789 @item @code{extra-options} (default: @var{'()})
23790 Extra options will be passed to @code{git daemon}, please run
23791 @command{man git-daemon} for more information.
23796 The @code{git://} protocol lacks authentication. When you pull from a
23797 repository fetched via @code{git://}, you don't know whether the data you
23798 receive was modified or is even coming from the specified host, and your
23799 connection is subject to eavesdropping. It's better to use an authenticated
23800 and encrypted transport, such as @code{https}. Although Git allows you
23801 to serve repositories using unsophisticated file-based web servers,
23802 there is a faster protocol implemented by the @code{git-http-backend}
23803 program. This program is the back-end of a proper Git web service. It
23804 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
23805 on running the necessary @code{fcgiwrap} daemon.
23807 Guix has a separate configuration data type for serving Git repositories
23810 @deftp {Data Type} git-http-configuration
23811 Data type representing the configuration for @code{git-http-service}.
23814 @item @code{package} (default: @var{git})
23815 Package object of the Git distributed version control system.
23817 @item @code{git-root} (default: @file{/srv/git})
23818 Directory containing the Git repositories to expose to the world.
23820 @item @code{export-all?} (default: @var{#f})
23821 Whether to expose access for all Git repositories in @var{git-root},
23822 even if they do not have the @file{git-daemon-export-ok} file.
23824 @item @code{uri-path} (default: @file{/git/})
23825 Path prefix for Git access. With the default @code{/git/} prefix, this
23826 will map @code{http://@var{server}/git/@var{repo}.git} to
23827 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
23828 with this prefix are not passed on to this Git instance.
23830 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
23831 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
23836 There is no @code{git-http-service-type}, currently; instead you can
23837 create an @code{nginx-location-configuration} from a
23838 @code{git-http-configuration} and then add that location to a web
23841 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
23842 [config=(git-http-configuration)]
23843 Compute an @code{nginx-location-configuration} that corresponds to the
23844 given Git http configuration. An example nginx service definition to
23845 serve the default @file{/srv/git} over HTTPS might be:
23848 (service nginx-service-type
23849 (nginx-configuration
23852 (nginx-server-configuration
23853 (listen '("443 ssl"))
23854 (server-name "git.my-host.org")
23856 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
23857 (ssl-certificate-key
23858 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
23861 (git-http-nginx-location-configuration
23862 (git-http-configuration (uri-path "/"))))))))))
23865 This example assumes that you are using Let's Encrypt to get your TLS
23866 certificate. @xref{Certificate Services}. The default @code{certbot}
23867 service will redirect all HTTP traffic on @code{git.my-host.org} to
23868 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
23869 system services. @xref{Web Services}.
23872 @subsubheading Cgit Service
23874 @cindex Cgit service
23875 @cindex Git, web interface
23876 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
23877 repositories written in C.
23879 The following example will configure the service with default values.
23880 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
23883 (service cgit-service-type)
23886 The @code{file-object} type designates either a file-like object
23887 (@pxref{G-Expressions, file-like objects}) or a string.
23889 @c %start of fragment
23891 Available @code{cgit-configuration} fields are:
23893 @deftypevr {@code{cgit-configuration} parameter} package package
23898 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
23899 NGINX configuration.
23903 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
23904 Specifies a command which will be invoked to format the content of about
23905 pages (both top-level and for each repository).
23907 Defaults to @samp{""}.
23911 @deftypevr {@code{cgit-configuration} parameter} string agefile
23912 Specifies a path, relative to each repository path, which can be used to
23913 specify the date and time of the youngest commit in the repository.
23915 Defaults to @samp{""}.
23919 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
23920 Specifies a command that will be invoked for authenticating repository
23923 Defaults to @samp{""}.
23927 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
23928 Flag which, when set to @samp{age}, enables date ordering in the branch
23929 ref list, and when set @samp{name} enables ordering by branch name.
23931 Defaults to @samp{"name"}.
23935 @deftypevr {@code{cgit-configuration} parameter} string cache-root
23936 Path used to store the cgit cache entries.
23938 Defaults to @samp{"/var/cache/cgit"}.
23942 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
23943 Number which specifies the time-to-live, in minutes, for the cached
23944 version of repository pages accessed with a fixed SHA1.
23946 Defaults to @samp{-1}.
23950 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
23951 Number which specifies the time-to-live, in minutes, for the cached
23952 version of repository pages accessed without a fixed SHA1.
23954 Defaults to @samp{5}.
23958 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
23959 Number which specifies the time-to-live, in minutes, for the cached
23960 version of the repository summary page.
23962 Defaults to @samp{5}.
23966 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
23967 Number which specifies the time-to-live, in minutes, for the cached
23968 version of the repository index page.
23970 Defaults to @samp{5}.
23974 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
23975 Number which specifies the time-to-live, in minutes, for the result of
23976 scanning a path for Git repositories.
23978 Defaults to @samp{15}.
23982 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23983 Number which specifies the time-to-live, in minutes, for the cached
23984 version of the repository about page.
23986 Defaults to @samp{15}.
23990 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
23991 Number which specifies the time-to-live, in minutes, for the cached
23992 version of snapshots.
23994 Defaults to @samp{5}.
23998 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
23999 The maximum number of entries in the cgit cache. When set to @samp{0},
24000 caching is disabled.
24002 Defaults to @samp{0}.
24006 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
24007 Sort items in the repo list case sensitively.
24009 Defaults to @samp{#t}.
24013 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
24014 List of common prefixes which, when combined with a repository URL,
24015 generates valid clone URLs for the repository.
24017 Defaults to @samp{()}.
24021 @deftypevr {@code{cgit-configuration} parameter} list clone-url
24022 List of @code{clone-url} templates.
24024 Defaults to @samp{()}.
24028 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
24029 Command which will be invoked to format commit messages.
24031 Defaults to @samp{""}.
24035 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
24036 Flag which, when set to @samp{date}, enables strict date ordering in the
24037 commit log, and when set to @samp{topo} enables strict topological
24040 Defaults to @samp{"git log"}.
24044 @deftypevr {@code{cgit-configuration} parameter} file-object css
24045 URL which specifies the css document to include in all cgit pages.
24047 Defaults to @samp{"/share/cgit/cgit.css"}.
24051 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
24052 Specifies a command which will be invoked to format names and email
24053 address of committers, authors, and taggers, as represented in various
24054 places throughout the cgit interface.
24056 Defaults to @samp{""}.
24060 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
24061 Flag which, when set to @samp{#t}, will make cgit generate a HTML
24062 fragment suitable for embedding in other HTML pages.
24064 Defaults to @samp{#f}.
24068 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
24069 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
24070 commit history graph to the left of the commit messages in the
24071 repository log page.
24073 Defaults to @samp{#f}.
24077 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
24078 Flag which, when set to @samp{#t}, allows all filter settings to be
24079 overridden in repository-specific cgitrc files.
24081 Defaults to @samp{#f}.
24085 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
24086 Flag which, when set to @samp{#t}, allows users to follow a file in the
24089 Defaults to @samp{#f}.
24093 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
24094 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
24097 Defaults to @samp{#t}.
24101 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
24102 Flag which, when set to @samp{#t}, will make cgit generate extra links
24103 "summary", "commit", "tree" for each repo in the repository index.
24105 Defaults to @samp{#f}.
24109 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
24110 Flag which, when set to @samp{#t}, will make cgit display the owner of
24111 each repo in the repository index.
24113 Defaults to @samp{#t}.
24117 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
24118 Flag which, when set to @samp{#t}, will make cgit print the number of
24119 modified files for each commit on the repository log page.
24121 Defaults to @samp{#f}.
24125 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
24126 Flag which, when set to @samp{#t}, will make cgit print the number of
24127 added and removed lines for each commit on the repository log page.
24129 Defaults to @samp{#f}.
24133 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
24134 Flag which, when set to @code{#t}, will make cgit display remote
24135 branches in the summary and refs views.
24137 Defaults to @samp{#f}.
24141 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
24142 Flag which, when set to @code{1}, will make cgit use the subject of the
24143 parent commit as link text when generating links to parent commits in
24146 Defaults to @samp{#f}.
24150 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
24151 Flag which, when set to @samp{#t}, will make cgit use the subject of the
24152 parent commit as link text when generating links to parent commits in
24155 Defaults to @samp{#f}.
24159 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
24160 Flag which, when set to @samp{#t}, will make cgit generate linenumber
24161 links for plaintext blobs printed in the tree view.
24163 Defaults to @samp{#t}.
24167 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
24168 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
24169 set any repo specific settings.
24171 Defaults to @samp{#f}.
24175 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
24176 URL used as link to a shortcut icon for cgit.
24178 Defaults to @samp{"/favicon.ico"}.
24182 @deftypevr {@code{cgit-configuration} parameter} string footer
24183 The content of the file specified with this option will be included
24184 verbatim at the bottom of all pages (i.e.@: it replaces the standard
24185 "generated by..."@: message).
24187 Defaults to @samp{""}.
24191 @deftypevr {@code{cgit-configuration} parameter} string head-include
24192 The content of the file specified with this option will be included
24193 verbatim in the HTML HEAD section on all pages.
24195 Defaults to @samp{""}.
24199 @deftypevr {@code{cgit-configuration} parameter} string header
24200 The content of the file specified with this option will be included
24201 verbatim at the top of all pages.
24203 Defaults to @samp{""}.
24207 @deftypevr {@code{cgit-configuration} parameter} file-object include
24208 Name of a configfile to include before the rest of the current config-
24211 Defaults to @samp{""}.
24215 @deftypevr {@code{cgit-configuration} parameter} string index-header
24216 The content of the file specified with this option will be included
24217 verbatim above the repository index.
24219 Defaults to @samp{""}.
24223 @deftypevr {@code{cgit-configuration} parameter} string index-info
24224 The content of the file specified with this option will be included
24225 verbatim below the heading on the repository index page.
24227 Defaults to @samp{""}.
24231 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24232 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24233 in the servers timezone.
24235 Defaults to @samp{#f}.
24239 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24240 URL which specifies the source of an image which will be used as a logo
24243 Defaults to @samp{"/share/cgit/cgit.png"}.
24247 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24248 URL loaded when clicking on the cgit logo image.
24250 Defaults to @samp{""}.
24254 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24255 Command which will be invoked to format the Owner column of the main
24258 Defaults to @samp{""}.
24262 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24263 Number of items to display in atom feeds view.
24265 Defaults to @samp{10}.
24269 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24270 Number of entries to list per page in "log" view.
24272 Defaults to @samp{50}.
24276 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24277 Number of commit message characters to display in "log" view.
24279 Defaults to @samp{80}.
24283 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24284 Specifies the number of entries to list per page on the repository index
24287 Defaults to @samp{50}.
24291 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24292 Specifies the maximum number of repo description characters to display
24293 on the repository index page.
24295 Defaults to @samp{80}.
24299 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24300 Specifies the maximum size of a blob to display HTML for in KBytes.
24302 Defaults to @samp{0}.
24306 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24307 Maximum statistics period. Valid values are @samp{week},@samp{month},
24308 @samp{quarter} and @samp{year}.
24310 Defaults to @samp{""}.
24314 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24315 Mimetype for the specified filename extension.
24317 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24318 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24319 "image/png") (svg "image/svg+xml"))}.
24323 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24324 Specifies the file to use for automatic mimetype lookup.
24326 Defaults to @samp{""}.
24330 @deftypevr {@code{cgit-configuration} parameter} string module-link
24331 Text which will be used as the formatstring for a hyperlink when a
24332 submodule is printed in a directory listing.
24334 Defaults to @samp{""}.
24338 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24339 If set to the value @samp{#t} caching will be disabled.
24341 Defaults to @samp{#f}.
24345 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24346 If set to @samp{#t} showing full author email addresses will be
24349 Defaults to @samp{#f}.
24353 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24354 Flag which, when set to @samp{#t}, will make cgit omit the standard
24355 header on all pages.
24357 Defaults to @samp{#f}.
24361 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24362 A list of subdirectories inside of @code{repository-directory}, relative
24363 to it, that should loaded as Git repositories. An empty list means that
24364 all subdirectories will be loaded.
24366 Defaults to @samp{()}.
24370 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24371 Text which will be used as default value for @code{cgit-repo-readme}.
24373 Defaults to @samp{""}.
24377 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24378 If set to @code{#t} and @code{repository-directory} is enabled, if any
24379 repositories are found with a suffix of @code{.git}, this suffix will be
24380 removed for the URL and name.
24382 Defaults to @samp{#f}.
24386 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24387 Maximum number of files to consider when detecting renames.
24389 Defaults to @samp{-1}.
24393 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24394 The way in which repositories in each section are sorted.
24396 Defaults to @samp{""}.
24400 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24401 Text used as content for the @code{robots} meta-tag.
24403 Defaults to @samp{("noindex" "nofollow")}.
24407 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24408 Text printed below the heading on the repository index page.
24410 Defaults to @samp{"a fast webinterface for the git dscm"}.
24414 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24415 The content of the file specified with this option will be included
24416 verbatim below thef "about" link on the repository index page.
24418 Defaults to @samp{""}.
24422 @deftypevr {@code{cgit-configuration} parameter} string root-title
24423 Text printed as heading on the repository index page.
24425 Defaults to @samp{""}.
24429 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24430 If set to @samp{#t} and repository-directory is enabled,
24431 repository-directory will recurse into directories whose name starts
24432 with a period. Otherwise, repository-directory will stay away from such
24433 directories, considered as "hidden". Note that this does not apply to
24434 the ".git" directory in non-bare repos.
24436 Defaults to @samp{#f}.
24440 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24441 Text which specifies the default set of snapshot formats that cgit
24442 generates links for.
24444 Defaults to @samp{()}.
24448 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24449 Name of the directory to scan for repositories (represents
24452 Defaults to @samp{"/srv/git"}.
24456 @deftypevr {@code{cgit-configuration} parameter} string section
24457 The name of the current repository section - all repositories defined
24458 after this option will inherit the current section name.
24460 Defaults to @samp{""}.
24464 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24465 Flag which, when set to @samp{1}, will sort the sections on the
24466 repository listing by name.
24468 Defaults to @samp{""}.
24472 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24473 A number which, if defined prior to repository-directory, specifies how
24474 many path elements from each repo path to use as a default section name.
24476 Defaults to @samp{0}.
24480 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24481 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24484 Defaults to @samp{#f}.
24488 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
24489 Specifies a command which will be invoked to format plaintext blobs in
24492 Defaults to @samp{""}.
24496 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
24497 Specifies the number of branches to display in the repository "summary"
24500 Defaults to @samp{10}.
24504 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
24505 Specifies the number of log entries to display in the repository
24508 Defaults to @samp{10}.
24512 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
24513 Specifies the number of tags to display in the repository "summary"
24516 Defaults to @samp{10}.
24520 @deftypevr {@code{cgit-configuration} parameter} string strict-export
24521 Filename which, if specified, needs to be present within the repository
24522 for cgit to allow access to that repository.
24524 Defaults to @samp{""}.
24528 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
24529 URL which, if specified, will be used as root for all cgit links.
24531 Defaults to @samp{"/"}.
24535 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
24536 A list of @dfn{cgit-repo} records to use with config.
24538 Defaults to @samp{()}.
24540 Available @code{repository-cgit-configuration} fields are:
24542 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
24543 A mask of snapshot formats for this repo that cgit generates links for,
24544 restricted by the global @code{snapshots} setting.
24546 Defaults to @samp{()}.
24550 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
24551 Override the default @code{source-filter}.
24553 Defaults to @samp{""}.
24557 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
24558 The relative URL used to access the repository.
24560 Defaults to @samp{""}.
24564 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
24565 Override the default @code{about-filter}.
24567 Defaults to @samp{""}.
24571 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
24572 Flag which, when set to @samp{age}, enables date ordering in the branch
24573 ref list, and when set to @samp{name} enables ordering by branch name.
24575 Defaults to @samp{""}.
24579 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
24580 A list of URLs which can be used to clone repo.
24582 Defaults to @samp{()}.
24586 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
24587 Override the default @code{commit-filter}.
24589 Defaults to @samp{""}.
24593 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
24594 Flag which, when set to @samp{date}, enables strict date ordering in the
24595 commit log, and when set to @samp{topo} enables strict topological
24598 Defaults to @samp{""}.
24602 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
24603 The name of the default branch for this repository. If no such branch
24604 exists in the repository, the first branch name (when sorted) is used as
24605 default instead. By default branch pointed to by HEAD, or "master" if
24606 there is no suitable HEAD.
24608 Defaults to @samp{""}.
24612 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
24613 The value to show as repository description.
24615 Defaults to @samp{""}.
24619 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
24620 The value to show as repository homepage.
24622 Defaults to @samp{""}.
24626 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
24627 Override the default @code{email-filter}.
24629 Defaults to @samp{""}.
24633 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
24634 A flag which can be used to disable the global setting
24635 @code{enable-commit-graph?}.
24637 Defaults to @samp{disabled}.
24641 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
24642 A flag which can be used to disable the global setting
24643 @code{enable-log-filecount?}.
24645 Defaults to @samp{disabled}.
24649 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
24650 A flag which can be used to disable the global setting
24651 @code{enable-log-linecount?}.
24653 Defaults to @samp{disabled}.
24657 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
24658 Flag which, when set to @code{#t}, will make cgit display remote
24659 branches in the summary and refs views.
24661 Defaults to @samp{disabled}.
24665 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
24666 A flag which can be used to override the global setting
24667 @code{enable-subject-links?}.
24669 Defaults to @samp{disabled}.
24673 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
24674 A flag which can be used to override the global setting
24675 @code{enable-html-serving?}.
24677 Defaults to @samp{disabled}.
24681 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
24682 Flag which, when set to @code{#t}, hides the repository from the
24685 Defaults to @samp{#f}.
24689 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
24690 Flag which, when set to @samp{#t}, ignores the repository.
24692 Defaults to @samp{#f}.
24696 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
24697 URL which specifies the source of an image which will be used as a logo
24698 on this repo’s pages.
24700 Defaults to @samp{""}.
24704 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
24705 URL loaded when clicking on the cgit logo image.
24707 Defaults to @samp{""}.
24711 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
24712 Override the default @code{owner-filter}.
24714 Defaults to @samp{""}.
24718 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
24719 Text which will be used as the formatstring for a hyperlink when a
24720 submodule is printed in a directory listing. The arguments for the
24721 formatstring are the path and SHA1 of the submodule commit.
24723 Defaults to @samp{""}.
24727 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
24728 Text which will be used as the formatstring for a hyperlink when a
24729 submodule with the specified subdirectory path is printed in a directory
24732 Defaults to @samp{()}.
24736 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
24737 Override the default maximum statistics period.
24739 Defaults to @samp{""}.
24743 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
24744 The value to show as repository name.
24746 Defaults to @samp{""}.
24750 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
24751 A value used to identify the owner of the repository.
24753 Defaults to @samp{""}.
24757 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
24758 An absolute path to the repository directory.
24760 Defaults to @samp{""}.
24764 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
24765 A path (relative to repo) which specifies a file to include verbatim as
24766 the "About" page for this repo.
24768 Defaults to @samp{""}.
24772 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
24773 The name of the current repository section - all repositories defined
24774 after this option will inherit the current section name.
24776 Defaults to @samp{""}.
24780 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
24781 Extra options will be appended to cgitrc file.
24783 Defaults to @samp{()}.
24789 @deftypevr {@code{cgit-configuration} parameter} list extra-options
24790 Extra options will be appended to cgitrc file.
24792 Defaults to @samp{()}.
24797 @c %end of fragment
24799 However, it could be that you just want to get a @code{cgitrc} up and
24800 running. In that case, you can pass an @code{opaque-cgit-configuration}
24801 as a record to @code{cgit-service-type}. As its name indicates, an
24802 opaque configuration does not have easy reflective capabilities.
24804 Available @code{opaque-cgit-configuration} fields are:
24806 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
24810 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
24811 The contents of the @code{cgitrc}, as a string.
24814 For example, if your @code{cgitrc} is just the empty string, you
24815 could instantiate a cgit service like this:
24818 (service cgit-service-type
24819 (opaque-cgit-configuration
24823 @subsubheading Gitolite Service
24825 @cindex Gitolite service
24826 @cindex Git, hosting
24827 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
24828 repositories on a central server.
24830 Gitolite can handle multiple repositories and users, and supports flexible
24831 configuration of the permissions for the users on the repositories.
24833 The following example will configure Gitolite using the default @code{git}
24834 user, and the provided SSH public key.
24837 (service gitolite-service-type
24838 (gitolite-configuration
24839 (admin-pubkey (plain-file
24841 "ssh-rsa AAAA... guix@@example.com"))))
24844 Gitolite is configured through a special admin repository which you can clone,
24845 for example, if you setup Gitolite on @code{example.com}, you would run the
24846 following command to clone the admin repository.
24849 git clone git@@example.com:gitolite-admin
24852 When the Gitolite service is activated, the provided @code{admin-pubkey} will
24853 be inserted in to the @file{keydir} directory in the gitolite-admin
24854 repository. If this results in a change in the repository, it will be
24855 committed using the message ``gitolite setup by GNU Guix''.
24857 @deftp {Data Type} gitolite-configuration
24858 Data type representing the configuration for @code{gitolite-service-type}.
24861 @item @code{package} (default: @var{gitolite})
24862 Gitolite package to use.
24864 @item @code{user} (default: @var{git})
24865 User to use for Gitolite. This will be user that you use when accessing
24868 @item @code{group} (default: @var{git})
24869 Group to use for Gitolite.
24871 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
24872 Directory in which to store the Gitolite configuration and repositories.
24874 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
24875 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
24876 representing the configuration for Gitolite.
24878 @item @code{admin-pubkey} (default: @var{#f})
24879 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
24880 setup Gitolite. This will be inserted in to the @file{keydir} directory
24881 within the gitolite-admin repository.
24883 To specify the SSH key as a string, use the @code{plain-file} function.
24886 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
24892 @deftp {Data Type} gitolite-rc-file
24893 Data type representing the Gitolite RC file.
24896 @item @code{umask} (default: @code{#o0077})
24897 This controls the permissions Gitolite sets on the repositories and their
24900 A value like @code{#o0027} will give read access to the group used by Gitolite
24901 (by default: @code{git}). This is necessary when using Gitolite with software
24902 like cgit or gitweb.
24904 @item @code{git-config-keys} (default: @code{""})
24905 Gitolite allows you to set git config values using the "config" keyword. This
24906 setting allows control over the config keys to accept.
24908 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
24909 Set the role names allowed to be used by users running the perms command.
24911 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
24912 This setting controls the commands and features to enable within Gitolite.
24918 @node Game Services
24919 @subsection Game Services
24921 @subsubheading The Battle for Wesnoth Service
24923 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
24924 based tactical strategy game, with several single player campaigns, and
24925 multiplayer games (both networked and local).
24927 @defvar {Scheme Variable} wesnothd-service-type
24928 Service type for the wesnothd service. Its value must be a
24929 @code{wesnothd-configuration} object. To run wesnothd in the default
24930 configuration, instantiate it as:
24933 (service wesnothd-service-type)
24937 @deftp {Data Type} wesnothd-configuration
24938 Data type representing the configuration of @command{wesnothd}.
24941 @item @code{package} (default: @code{wesnoth-server})
24942 The wesnoth server package to use.
24944 @item @code{port} (default: @code{15000})
24945 The port to bind the server to.
24950 @node PAM Mount Service
24951 @subsection PAM Mount Service
24954 The @code{(gnu services pam-mount)} module provides a service allowing
24955 users to mount volumes when they log in. It should be able to mount any
24956 volume format supported by the system.
24958 @defvar {Scheme Variable} pam-mount-service-type
24959 Service type for PAM Mount support.
24962 @deftp {Data Type} pam-mount-configuration
24963 Data type representing the configuration of PAM Mount.
24965 It takes the following parameters:
24969 The configuration rules that will be used to generate
24970 @file{/etc/security/pam_mount.conf.xml}.
24972 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
24973 Guile Reference Manual}), and the the default ones don't mount anything
24974 for anyone at login:
24977 `((debug (@@ (enable "0")))
24978 (mntoptions (@@ (allow ,(string-join
24979 '("nosuid" "nodev" "loop"
24980 "encryption" "fsck" "nonempty"
24981 "allow_root" "allow_other")
24983 (mntoptions (@@ (require "nosuid,nodev")))
24984 (logout (@@ (wait "0")
24988 (mkmountpoint (@@ (enable "1")
24992 Some @code{volume} elements must be added to automatically mount volumes
24993 at login. Here's an example allowing the user @code{alice} to mount her
24994 encrypted @code{HOME} directory and allowing the user @code{bob} to mount
24995 the partition where he stores his data:
24998 (define pam-mount-rules
24999 `((debug (@@ (enable "0")))
25000 (volume (@@ (user "alice")
25003 (mountpoint "/home/alice")))
25004 (volume (@@ (user "bob")
25007 (mountpoint "/home/bob/data")
25008 (options "defaults,autodefrag,compress")))
25009 (mntoptions (@@ (allow ,(string-join
25010 '("nosuid" "nodev" "loop"
25011 "encryption" "fsck" "nonempty"
25012 "allow_root" "allow_other")
25014 (mntoptions (@@ (require "nosuid,nodev")))
25015 (logout (@@ (wait "0")
25019 (mkmountpoint (@@ (enable "1")
25020 (remove "true")))))
25022 (service pam-mount-service-type
25023 (pam-mount-configuration
25024 (rules pam-mount-rules)))
25027 The complete list of possible options can be found in the man page for
25028 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
25033 @node Guix Services
25034 @subsection Guix Services
25036 @subsubheading Guix Data Service
25037 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
25038 and provides data about GNU Guix. This includes information about
25039 packages, derivations and lint warnings.
25041 The data is stored in a PostgreSQL database, and available through a web
25044 @defvar {Scheme Variable} guix-data-service-type
25045 Service type for the Guix Data Service. Its value must be a
25046 @code{guix-data-service-configuration} object. The service optionally
25047 extends the getmail service, as the guix-commits mailing list is used to
25048 find out about changes in the Guix git repository.
25051 @deftp {Data Type} guix-data-service-configuration
25052 Data type representing the configuration of the Guix Data Service.
25055 @item @code{package} (default: @code{guix-data-service})
25056 The Guix Data Service package to use.
25058 @item @code{user} (default: @code{"guix-data-service"})
25059 The system user to run the service as.
25061 @item @code{group} (default: @code{"guix-data-service"})
25062 The system group to run the service as.
25064 @item @code{port} (default: @code{8765})
25065 The port to bind the web service to.
25067 @item @code{host} (default: @code{"127.0.0.1"})
25068 The host to bind the web service to.
25070 @item @code{getmail-idle-mailboxes} (default: @code{#f})
25071 If set, this is the list of mailboxes that the getmail service will be
25072 configured to listen to.
25074 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
25075 If set, this is the @code{getmail-retriever-configuration} object with
25076 which to configure getmail to fetch mail from the guix-commits mailing
25083 @node Miscellaneous Services
25084 @subsection Miscellaneous Services
25086 @cindex fingerprint
25087 @subsubheading Fingerprint Service
25089 The @code{(gnu services authentication)} module provides a DBus service to
25090 read and identify fingerprints via a fingerprint sensor.
25092 @defvr {Scheme Variable} fprintd-service-type
25093 The service type for @command{fprintd}, which provides the fingerprint
25094 reading capability.
25097 (service fprintd-service-type)
25102 @subsubheading System Control Service
25104 The @code{(gnu services sysctl)} provides a service to configure kernel
25105 parameters at boot.
25107 @defvr {Scheme Variable} sysctl-service-type
25108 The service type for @command{sysctl}, which modifies kernel parameters
25109 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
25113 (service sysctl-service-type
25114 (sysctl-configuration
25115 (settings '(("net.ipv4.ip_forward" . "1")))))
25119 @deftp {Data Type} sysctl-configuration
25120 The data type representing the configuration of @command{sysctl}.
25123 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
25124 The @command{sysctl} executable to use.
25126 @item @code{settings} (default: @code{'()})
25127 An association list specifies kernel parameters and their values.
25132 @subsubheading PC/SC Smart Card Daemon Service
25134 The @code{(gnu services security-token)} module provides the following service
25135 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
25136 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
25137 manager that coordinates communications with smart card readers, smart cards
25138 and cryptographic tokens that are connected to the system.
25140 @defvr {Scheme Variable} pcscd-service-type
25141 Service type for the @command{pcscd} service. Its value must be a
25142 @code{pcscd-configuration} object. To run pcscd in the default
25143 configuration, instantiate it as:
25146 (service pcscd-service-type)
25150 @deftp {Data Type} pcscd-configuration
25151 The data type representing the configuration of @command{pcscd}.
25154 @item @code{pcsc-lite} (default: @code{pcsc-lite})
25155 The pcsc-lite package that provides pcscd.
25156 @item @code{usb-drivers} (default: @code{(list ccid)})
25157 List of packages that provide USB drivers to pcscd. Drivers are expected to be
25158 under @file{pcsc/drivers} in the store directory of the package.
25163 @subsubheading Lirc Service
25165 The @code{(gnu services lirc)} module provides the following service.
25167 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
25168 [#:device #f] [#:driver #f] [#:config-file #f] @
25169 [#:extra-options '()]
25170 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
25171 decodes infrared signals from remote controls.
25173 Optionally, @var{device}, @var{driver} and @var{config-file}
25174 (configuration file name) may be specified. See @command{lircd} manual
25177 Finally, @var{extra-options} is a list of additional command-line options
25178 passed to @command{lircd}.
25182 @subsubheading Spice Service
25184 The @code{(gnu services spice)} module provides the following service.
25186 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
25187 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
25188 that enables sharing the clipboard with a vm and setting the guest display
25189 resolution when the graphical console window resizes.
25192 @cindex inputattach
25193 @subsubheading inputattach Service
25195 @cindex tablet input, for Xorg
25196 @cindex touchscreen input, for Xorg
25197 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
25198 use input devices such as Wacom tablets, touchscreens, or joysticks with the
25199 Xorg display server.
25201 @deffn {Scheme Variable} inputattach-service-type
25202 Type of a service that runs @command{inputattach} on a device and
25203 dispatches events from it.
25206 @deftp {Data Type} inputattach-configuration
25208 @item @code{device-type} (default: @code{"wacom"})
25209 The type of device to connect to. Run @command{inputattach --help}, from the
25210 @code{inputattach} package, to see the list of supported device types.
25212 @item @code{device} (default: @code{"/dev/ttyS0"})
25213 The device file to connect to the device.
25215 @item @code{baud-rate} (default: @code{#f})
25216 Baud rate to use for the serial connection.
25217 Should be a number or @code{#f}.
25219 @item @code{log-file} (default: @code{#f})
25220 If true, this must be the name of a file to log messages to.
25224 @subsection Dictionary Services
25226 The @code{(gnu services dict)} module provides the following service:
25228 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25229 Return a service that runs the @command{dicod} daemon, an implementation
25230 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25232 The optional @var{config} argument specifies the configuration for
25233 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25234 default it serves the GNU Collaborative International Dictonary of English.
25236 You can add @command{open localhost} to your @file{~/.dico} file to make
25237 @code{localhost} the default server for @command{dico} client
25238 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25241 @deftp {Data Type} dicod-configuration
25242 Data type representing the configuration of dicod.
25245 @item @code{dico} (default: @var{dico})
25246 Package object of the GNU Dico dictionary server.
25248 @item @code{interfaces} (default: @var{'("localhost")})
25249 This is the list of IP addresses and ports and possibly socket file
25250 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25251 dico, GNU Dico Manual}).
25253 @item @code{handlers} (default: @var{'()})
25254 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25256 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25257 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25261 @deftp {Data Type} dicod-handler
25262 Data type representing a dictionary handler (module instance).
25266 Name of the handler (module instance).
25268 @item @code{module} (default: @var{#f})
25269 Name of the dicod module of the handler (instance). If it is @code{#f},
25270 the module has the same name as the handler.
25271 (@pxref{Modules,,, dico, GNU Dico Manual}).
25273 @item @code{options}
25274 List of strings or gexps representing the arguments for the module handler
25278 @deftp {Data Type} dicod-database
25279 Data type representing a dictionary database.
25283 Name of the database, will be used in DICT commands.
25285 @item @code{handler}
25286 Name of the dicod handler (module instance) used by this database
25287 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25289 @item @code{complex?} (default: @var{#f})
25290 Whether the database configuration complex. The complex configuration
25291 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25293 @item @code{options}
25294 List of strings or gexps representing the arguments for the database
25295 (@pxref{Databases,,, dico, GNU Dico Manual}).
25299 @defvr {Scheme Variable} %dicod-database:gcide
25300 A @code{<dicod-database>} object serving the GNU Collaborative International
25301 Dictionary of English using the @code{gcide} package.
25304 The following is an example @code{dicod-service} configuration.
25307 (dicod-service #:config
25308 (dicod-configuration
25309 (handlers (list (dicod-handler
25313 (list #~(string-append "dbdir=" #$wordnet))))))
25314 (databases (list (dicod-database
25317 (handler "wordnet")
25318 (options '("database=wn")))
25319 %dicod-database:gcide))))
25323 @subsubheading Docker Service
25325 The @code{(gnu services docker)} module provides the following services.
25327 @defvr {Scheme Variable} docker-service-type
25329 This is the type of the service that runs @url{https://www.docker.com,Docker},
25330 a daemon that can execute application bundles (sometimes referred to as
25331 ``containers'') in isolated environments.
25335 @deftp {Data Type} docker-configuration
25336 This is the data type representing the configuration of Docker and Containerd.
25340 @item @code{package} (default: @code{docker})
25341 The Docker package to use.
25343 @item @code{containerd} (default: @var{containerd})
25344 The Containerd package to use.
25350 @subsubheading Auditd Service
25352 The @code{(gnu services auditd)} module provides the following service.
25354 @defvr {Scheme Variable} auditd-service-type
25356 This is the type of the service that runs
25357 @url{https://people.redhat.com/sgrubb/audit/,auditd},
25358 a daemon that tracks security-relevant information on your system.
25360 Examples of things that can be tracked:
25370 Failed login attempts
25377 @command{auditctl} from the @code{audit} package can be used in order
25378 to add or remove events to be tracked (until the next reboot).
25379 In order to permanently track events, put the command line arguments
25380 of auditctl into @file{/etc/audit/audit.rules}.
25381 @command{aureport} from the @code{audit} package can be used in order
25382 to view a report of all recorded events.
25383 The audit daemon usually logs into the directory @file{/var/log/audit}.
25387 @deftp {Data Type} auditd-configuration
25388 This is the data type representing the configuration of auditd.
25392 @item @code{audit} (default: @code{audit})
25393 The audit package to use.
25398 @defvr {Scheme Variable} singularity-service-type
25399 This is the type of the service that allows you to run
25400 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
25401 create and run application bundles (aka. ``containers''). The value for this
25402 service is the Singularity package to use.
25404 The service does not install a daemon; instead, it installs helper programs as
25405 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
25406 @command{singularity run} and similar commands.
25410 @subsubheading Nix service
25412 The @code{(gnu services nix)} module provides the following service.
25414 @defvr {Scheme Variable} nix-service-type
25416 This is the type of the service that runs build daemon of the
25417 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
25421 (use-modules (gnu))
25422 (use-service-modules nix)
25423 (use-package-modules package-management)
25427 (packages (append (list nix)
25430 (services (append (list (service nix-service-type))
25434 After @command{guix system reconfigure} configure Nix for your user:
25437 @item Add a Nix channel and update it. See
25438 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
25440 @item Create a symlink to your profile and activate Nix profile:
25444 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
25445 $ source /run/current-system/profile/etc/profile.d/nix.sh
25450 @node Setuid Programs
25451 @section Setuid Programs
25453 @cindex setuid programs
25454 Some programs need to run with ``root'' privileges, even when they are
25455 launched by unprivileged users. A notorious example is the
25456 @command{passwd} program, which users can run to change their
25457 password, and which needs to access the @file{/etc/passwd} and
25458 @file{/etc/shadow} files---something normally restricted to root, for
25459 obvious security reasons. To address that, these executables are
25460 @dfn{setuid-root}, meaning that they always run with root privileges
25461 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
25462 for more info about the setuid mechanism.)
25464 The store itself @emph{cannot} contain setuid programs: that would be a
25465 security issue since any user on the system can write derivations that
25466 populate the store (@pxref{The Store}). Thus, a different mechanism is
25467 used: instead of changing the setuid bit directly on files that are in
25468 the store, we let the system administrator @emph{declare} which programs
25469 should be setuid root.
25471 The @code{setuid-programs} field of an @code{operating-system}
25472 declaration contains a list of G-expressions denoting the names of
25473 programs to be setuid-root (@pxref{Using the Configuration System}).
25474 For instance, the @command{passwd} program, which is part of the Shadow
25475 package, can be designated by this G-expression (@pxref{G-Expressions}):
25478 #~(string-append #$shadow "/bin/passwd")
25481 A default set of setuid programs is defined by the
25482 @code{%setuid-programs} variable of the @code{(gnu system)} module.
25484 @defvr {Scheme Variable} %setuid-programs
25485 A list of G-expressions denoting common programs that are setuid-root.
25487 The list includes commands such as @command{passwd}, @command{ping},
25488 @command{su}, and @command{sudo}.
25491 Under the hood, the actual setuid programs are created in the
25492 @file{/run/setuid-programs} directory at system activation time. The
25493 files in this directory refer to the ``real'' binaries, which are in the
25496 @node X.509 Certificates
25497 @section X.509 Certificates
25499 @cindex HTTPS, certificates
25500 @cindex X.509 certificates
25502 Web servers available over HTTPS (that is, HTTP over the transport-layer
25503 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
25504 that the client can then use to @emph{authenticate} the server. To do
25505 that, clients verify that the server's certificate is signed by a
25506 so-called @dfn{certificate authority} (CA). But to verify the CA's
25507 signature, clients must have first acquired the CA's certificate.
25509 Web browsers such as GNU@tie{}IceCat include their own set of CA
25510 certificates, such that they are able to verify CA signatures
25513 However, most other programs that can talk HTTPS---@command{wget},
25514 @command{git}, @command{w3m}, etc.---need to be told where CA
25515 certificates can be found.
25517 @cindex @code{nss-certs}
25518 In Guix, this is done by adding a package that provides certificates
25519 to the @code{packages} field of the @code{operating-system} declaration
25520 (@pxref{operating-system Reference}). Guix includes one such package,
25521 @code{nss-certs}, which is a set of CA certificates provided as part of
25522 Mozilla's Network Security Services.
25524 Note that it is @emph{not} part of @code{%base-packages}, so you need to
25525 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
25526 most applications and libraries look for certificates by default, points
25527 to the certificates installed globally.
25529 Unprivileged users, including users of Guix on a foreign distro,
25530 can also install their own certificate package in
25531 their profile. A number of environment variables need to be defined so
25532 that applications and libraries know where to find them. Namely, the
25533 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
25534 variables. Some applications add their own environment variables; for
25535 instance, the Git version control system honors the certificate bundle
25536 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
25537 would typically run something like:
25540 $ guix install nss-certs
25541 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
25542 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25543 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
25546 As another example, R requires the @code{CURL_CA_BUNDLE} environment
25547 variable to point to a certificate bundle, so you would have to run
25548 something like this:
25551 $ guix install nss-certs
25552 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25555 For other applications you may want to look up the required environment
25556 variable in the relevant documentation.
25559 @node Name Service Switch
25560 @section Name Service Switch
25562 @cindex name service switch
25564 The @code{(gnu system nss)} module provides bindings to the
25565 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
25566 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
25567 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
25568 extended with new ``name'' lookup methods for system databases, which
25569 includes host names, service names, user accounts, and more (@pxref{Name
25570 Service Switch, System Databases and Name Service Switch,, libc, The GNU
25571 C Library Reference Manual}).
25573 The NSS configuration specifies, for each system database, which lookup
25574 method is to be used, and how the various methods are chained
25575 together---for instance, under which circumstances NSS should try the
25576 next method in the list. The NSS configuration is given in the
25577 @code{name-service-switch} field of @code{operating-system} declarations
25578 (@pxref{operating-system Reference, @code{name-service-switch}}).
25581 @cindex .local, host name lookup
25582 As an example, the declaration below configures the NSS to use the
25583 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
25584 back-end}, which supports host name lookups over multicast DNS (mDNS)
25585 for host names ending in @code{.local}:
25588 (name-service-switch
25589 (hosts (list %files ;first, check /etc/hosts
25591 ;; If the above did not succeed, try
25592 ;; with 'mdns_minimal'.
25594 (name "mdns_minimal")
25596 ;; 'mdns_minimal' is authoritative for
25597 ;; '.local'. When it returns "not found",
25598 ;; no need to try the next methods.
25599 (reaction (lookup-specification
25600 (not-found => return))))
25602 ;; Then fall back to DNS.
25606 ;; Finally, try with the "full" 'mdns'.
25611 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
25612 contains this configuration, so you will not have to type it if all you
25613 want is to have @code{.local} host lookup working.
25615 Note that, in this case, in addition to setting the
25616 @code{name-service-switch} of the @code{operating-system} declaration,
25617 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
25618 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
25619 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
25620 to the name service cache daemon (@pxref{Base Services,
25621 @code{nscd-service}}).
25623 For convenience, the following variables provide typical NSS
25626 @defvr {Scheme Variable} %default-nss
25627 This is the default name service switch configuration, a
25628 @code{name-service-switch} object.
25631 @defvr {Scheme Variable} %mdns-host-lookup-nss
25632 This is the name service switch configuration with support for host name
25633 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
25636 The reference for name service switch configuration is given below. It
25637 is a direct mapping of the configuration file format of the C library , so
25638 please refer to the C library manual for more information (@pxref{NSS
25639 Configuration File,,, libc, The GNU C Library Reference Manual}).
25640 Compared to the configuration file format of libc NSS, it has the advantage
25641 not only of adding this warm parenthetic feel that we like, but also
25642 static checks: you will know about syntax errors and typos as soon as you
25643 run @command{guix system}.
25645 @deftp {Data Type} name-service-switch
25647 This is the data type representation the configuration of libc's name
25648 service switch (NSS). Each field below represents one of the supported
25665 The system databases handled by the NSS. Each of these fields must be a
25666 list of @code{<name-service>} objects (see below).
25670 @deftp {Data Type} name-service
25672 This is the data type representing an actual name service and the
25673 associated lookup action.
25677 A string denoting the name service (@pxref{Services in the NSS
25678 configuration,,, libc, The GNU C Library Reference Manual}).
25680 Note that name services listed here must be visible to nscd. This is
25681 achieved by passing the @code{#:name-services} argument to
25682 @code{nscd-service} the list of packages providing the needed name
25683 services (@pxref{Base Services, @code{nscd-service}}).
25686 An action specified using the @code{lookup-specification} macro
25687 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
25688 Reference Manual}). For example:
25691 (lookup-specification (unavailable => continue)
25692 (success => return))
25697 @node Initial RAM Disk
25698 @section Initial RAM Disk
25701 @cindex initial RAM disk
25702 For bootstrapping purposes, the Linux-Libre kernel is passed an
25703 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
25704 root file system as well as an initialization script. The latter is
25705 responsible for mounting the real root file system, and for loading any
25706 kernel modules that may be needed to achieve that.
25708 The @code{initrd-modules} field of an @code{operating-system}
25709 declaration allows you to specify Linux-libre kernel modules that must
25710 be available in the initrd. In particular, this is where you would list
25711 modules needed to actually drive the hard disk where your root partition
25712 is---although the default value of @code{initrd-modules} should cover
25713 most use cases. For example, assuming you need the @code{megaraid_sas}
25714 module in addition to the default modules to be able to access your root
25715 file system, you would write:
25720 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
25723 @defvr {Scheme Variable} %base-initrd-modules
25724 This is the list of kernel modules included in the initrd by default.
25727 Furthermore, if you need lower-level customization, the @code{initrd}
25728 field of an @code{operating-system} declaration allows
25729 you to specify which initrd you would like to use. The @code{(gnu
25730 system linux-initrd)} module provides three ways to build an initrd: the
25731 high-level @code{base-initrd} procedure and the low-level
25732 @code{raw-initrd} and @code{expression->initrd} procedures.
25734 The @code{base-initrd} procedure is intended to cover most common uses.
25735 For example, if you want to add a bunch of kernel modules to be loaded
25736 at boot time, you can define the @code{initrd} field of the operating
25737 system declaration like this:
25740 (initrd (lambda (file-systems . rest)
25741 ;; Create a standard initrd but set up networking
25742 ;; with the parameters QEMU expects by default.
25743 (apply base-initrd file-systems
25744 #:qemu-networking? #t
25748 The @code{base-initrd} procedure also handles common use cases that
25749 involves using the system as a QEMU guest, or as a ``live'' system with
25750 volatile root file system.
25752 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
25753 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
25754 such as trying to guess which kernel modules and packages should be included
25755 to the initrd. An example use of @code{raw-initrd} is when a user has
25756 a custom Linux kernel configuration and default kernel modules included by
25757 @code{base-initrd} are not available.
25759 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
25760 honors several options passed on the Linux kernel command line
25761 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
25762 @code{-append} option of QEMU), notably:
25765 @item --load=@var{boot}
25766 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
25767 program, once it has mounted the root file system.
25769 Guix uses this option to yield control to a boot program that runs the
25770 service activation programs and then spawns the GNU@tie{}Shepherd, the
25771 initialization system.
25773 @item --root=@var{root}
25774 Mount @var{root} as the root file system. @var{root} can be a
25775 device name like @code{/dev/sda1}, a file system label, or a file system
25778 @item --system=@var{system}
25779 Have @file{/run/booted-system} and @file{/run/current-system} point to
25782 @item modprobe.blacklist=@var{modules}@dots{}
25783 @cindex module, black-listing
25784 @cindex black list, of kernel modules
25785 Instruct the initial RAM disk as well as the @command{modprobe} command
25786 (from the kmod package) to refuse to load @var{modules}. @var{modules}
25787 must be a comma-separated list of module names---e.g.,
25788 @code{usbkbd,9pnet}.
25791 Start a read-eval-print loop (REPL) from the initial RAM disk before it
25792 tries to load kernel modules and to mount the root file system. Our
25793 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
25794 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
25795 Manual}, for more information on Guile's REPL.
25799 Now that you know all the features that initial RAM disks produced by
25800 @code{base-initrd} and @code{raw-initrd} provide,
25801 here is how to use it and customize it further.
25804 @cindex initial RAM disk
25805 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
25806 [#:linux-modules '()] [#:mapped-devices '()] @
25807 [#:keyboard-layout #f] @
25808 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
25809 Return a derivation that builds a raw initrd. @var{file-systems} is
25810 a list of file systems to be mounted by the initrd, possibly in addition to
25811 the root file system specified on the kernel command line via @code{--root}.
25812 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
25813 @var{mapped-devices} is a list of device mappings to realize before
25814 @var{file-systems} are mounted (@pxref{Mapped Devices}).
25815 @var{helper-packages} is a list of packages to be copied in the initrd. It may
25816 include @code{e2fsck/static} or other packages needed by the initrd to check
25817 the root file system.
25819 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25820 the desired console keyboard layout. This is done before @var{mapped-devices}
25821 are set up and before @var{file-systems} are mounted such that, should the
25822 user need to enter a passphrase or use the REPL, this happens using the
25823 intended keyboard layout.
25825 When @var{qemu-networking?} is true, set up networking with the standard QEMU
25826 parameters. When @var{virtio?} is true, load additional modules so that the
25827 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
25829 When @var{volatile-root?} is true, the root file system is writable but any changes
25833 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
25834 [#:mapped-devices '()] [#:keyboard-layout #f] @
25835 [#:qemu-networking? #f] [#:volatile-root? #f] @
25836 [#:linux-modules '()]
25837 Return as a file-like object a generic initrd, with kernel
25838 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
25839 mounted by the initrd, possibly in addition to the root file system specified
25840 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
25841 mappings to realize before @var{file-systems} are mounted.
25843 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25844 the desired console keyboard layout. This is done before @var{mapped-devices}
25845 are set up and before @var{file-systems} are mounted such that, should the
25846 user need to enter a passphrase or use the REPL, this happens using the
25847 intended keyboard layout.
25849 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
25851 The initrd is automatically populated with all the kernel modules necessary
25852 for @var{file-systems} and for the given options. Additional kernel
25853 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
25854 loaded at boot time in the order in which they appear.
25857 Needless to say, the initrds we produce and use embed a
25858 statically-linked Guile, and the initialization program is a Guile
25859 program. That gives a lot of flexibility. The
25860 @code{expression->initrd} procedure builds such an initrd, given the
25861 program to run in that initrd.
25863 @deffn {Scheme Procedure} expression->initrd @var{exp} @
25864 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
25865 Return as a file-like object a Linux initrd (a gzipped cpio archive)
25866 containing @var{guile} and that evaluates @var{exp}, a G-expression,
25867 upon booting. All the derivations referenced by @var{exp} are
25868 automatically copied to the initrd.
25871 @node Bootloader Configuration
25872 @section Bootloader Configuration
25875 @cindex boot loader
25877 The operating system supports multiple bootloaders. The bootloader is
25878 configured using @code{bootloader-configuration} declaration. All the
25879 fields of this structure are bootloader agnostic except for one field,
25880 @code{bootloader} that indicates the bootloader to be configured and
25883 Some of the bootloaders do not honor every field of
25884 @code{bootloader-configuration}. For instance, the extlinux
25885 bootloader does not support themes and thus ignores the @code{theme}
25888 @deftp {Data Type} bootloader-configuration
25889 The type of a bootloader configuration declaration.
25893 @item @code{bootloader}
25894 @cindex EFI, bootloader
25895 @cindex UEFI, bootloader
25896 @cindex BIOS, bootloader
25897 The bootloader to use, as a @code{bootloader} object. For now
25898 @code{grub-bootloader}, @code{grub-efi-bootloader},
25899 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
25901 @vindex grub-efi-bootloader
25902 @code{grub-efi-bootloader} allows to boot on modern systems using the
25903 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
25904 use if the installation image contains a @file{/sys/firmware/efi} directory
25905 when you boot it on your system.
25907 @vindex grub-bootloader
25908 @code{grub-bootloader} allows you to boot in particular Intel-based machines
25909 in ``legacy'' BIOS mode.
25911 @cindex ARM, bootloaders
25912 @cindex AArch64, bootloaders
25913 Available bootloaders are described in @code{(gnu bootloader @dots{})}
25914 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
25915 of bootloaders for a wide range of ARM and AArch64 systems, using the
25916 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
25918 @item @code{target}
25919 This is a string denoting the target onto which to install the
25922 The interpretation depends on the bootloader in question. For
25923 @code{grub-bootloader}, for example, it should be a device name understood by
25924 the bootloader @command{installer} command, such as @code{/dev/sda} or
25925 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
25926 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
25927 system, usually @file{/boot/efi}.
25929 @item @code{menu-entries} (default: @code{()})
25930 A possibly empty list of @code{menu-entry} objects (see below), denoting
25931 entries to appear in the bootloader menu, in addition to the current
25932 system entry and the entry pointing to previous system generations.
25934 @item @code{default-entry} (default: @code{0})
25935 The index of the default boot menu entry. Index 0 is for the entry of the
25938 @item @code{timeout} (default: @code{5})
25939 The number of seconds to wait for keyboard input before booting. Set to
25940 0 to boot immediately, and to -1 to wait indefinitely.
25942 @cindex keyboard layout, for the bootloader
25943 @item @code{keyboard-layout} (default: @code{#f})
25944 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
25945 layout, usually US@tie{}English (``qwerty'').
25947 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
25951 This option is currently ignored by bootloaders other than @code{grub} and
25955 @item @code{theme} (default: @var{#f})
25956 The bootloader theme object describing the theme to use. If no theme
25957 is provided, some bootloaders might use a default theme, that's true
25960 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
25961 The output terminals used for the bootloader boot menu, as a list of
25962 symbols. GRUB accepts the values: @code{console}, @code{serial},
25963 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
25964 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
25965 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
25966 configuration,,, grub,GNU GRUB manual}).
25968 @item @code{terminal-inputs} (default: @code{'()})
25969 The input terminals used for the bootloader boot menu, as a list of
25970 symbols. For GRUB, the default is the native platform terminal as
25971 determined at run-time. GRUB accepts the values: @code{console},
25972 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
25973 @code{usb_keyboard}. This field corresponds to the GRUB variable
25974 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
25977 @item @code{serial-unit} (default: @code{#f})
25978 The serial unit used by the bootloader, as an integer from 0 to 3.
25979 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
25980 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25982 @item @code{serial-speed} (default: @code{#f})
25983 The speed of the serial interface, as an integer. For GRUB, the
25984 default value is chosen at run-time; currently GRUB chooses
25985 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25992 Should you want to list additional boot menu entries @i{via} the
25993 @code{menu-entries} field above, you will need to create them with the
25994 @code{menu-entry} form. For example, imagine you want to be able to
25995 boot another distro (hard to imagine!), you can define a menu entry
26000 (label "The Other Distro")
26001 (linux "/boot/old/vmlinux-2.6.32")
26002 (linux-arguments '("root=/dev/sda2"))
26003 (initrd "/boot/old/initrd"))
26008 @deftp {Data Type} menu-entry
26009 The type of an entry in the bootloader menu.
26014 The label to show in the menu---e.g., @code{"GNU"}.
26017 The Linux kernel image to boot, for example:
26020 (file-append linux-libre "/bzImage")
26023 For GRUB, it is also possible to specify a device explicitly in the
26024 file path using GRUB's device naming convention (@pxref{Naming
26025 convention,,, grub, GNU GRUB manual}), for example:
26028 "(hd0,msdos1)/boot/vmlinuz"
26031 If the device is specified explicitly as above, then the @code{device}
26032 field is ignored entirely.
26034 @item @code{linux-arguments} (default: @code{()})
26035 The list of extra Linux kernel command-line arguments---e.g.,
26036 @code{("console=ttyS0")}.
26038 @item @code{initrd}
26039 A G-Expression or string denoting the file name of the initial RAM disk
26040 to use (@pxref{G-Expressions}).
26041 @item @code{device} (default: @code{#f})
26042 The device where the kernel and initrd are to be found---i.e., for GRUB,
26043 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
26045 This may be a file system label (a string), a file system UUID (a
26046 bytevector, @pxref{File Systems}), or @code{#f}, in which case
26047 the bootloader will search the device containing the file specified by
26048 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
26049 must @emph{not} be an OS device name such as @file{/dev/sda1}.
26054 @c FIXME: Write documentation once it's stable.
26055 For now only GRUB has theme support. GRUB themes are created using
26056 the @code{grub-theme} form, which is not documented yet.
26058 @defvr {Scheme Variable} %default-theme
26059 This is the default GRUB theme used by the operating system if no
26060 @code{theme} field is specified in @code{bootloader-configuration}
26063 It comes with a fancy background image displaying the GNU and Guix
26068 @node Invoking guix system
26069 @section Invoking @code{guix system}
26071 Once you have written an operating system declaration as seen in the
26072 previous section, it can be @dfn{instantiated} using the @command{guix
26073 system} command. The synopsis is:
26076 guix system @var{options}@dots{} @var{action} @var{file}
26079 @var{file} must be the name of a file containing an
26080 @code{operating-system} declaration. @var{action} specifies how the
26081 operating system is instantiated. Currently the following values are
26086 Display available service type definitions that match the given regular
26087 expressions, sorted by relevance:
26093 $ guix system search console
26094 name: console-fonts
26095 location: gnu/services/base.scm:806:2
26096 extends: shepherd-root
26097 description: Install the given fonts on the specified ttys (fonts are per
26098 + virtual console on GNU/Linux). The value of this service is a list of
26099 + tty/font pairs. The font can be the name of a font provided by the `kbd'
26100 + package or any valid argument to `setfont', as in this example:
26102 + '(("tty1" . "LatGrkCyr-8x16")
26103 + ("tty2" . (file-append
26105 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
26106 + ("tty3" . (file-append
26108 + "/share/consolefonts/ter-132n"))) ; for HDPI
26112 location: gnu/services/base.scm:1190:2
26113 extends: shepherd-root
26114 description: Provide console login using the `mingetty' program.
26118 location: gnu/services/base.scm:860:2
26120 description: Provide a console log-in service as specified by its
26121 + configuration value, a `login-configuration' object.
26127 As for @command{guix package --search}, the result is written in
26128 @code{recutils} format, which makes it easy to filter the output
26129 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
26132 Build the operating system described in @var{file}, activate it, and
26133 switch to it@footnote{This action (and the related actions
26134 @code{switch-generation} and @code{roll-back}) are usable only on
26135 systems already running Guix System.}.
26138 @c The paragraph below refers to the problem discussed at
26139 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
26140 It is highly recommended to run @command{guix pull} once before you run
26141 @command{guix system reconfigure} for the first time (@pxref{Invoking
26142 guix pull}). Failing to do that you would see an older version of Guix
26143 once @command{reconfigure} has completed.
26146 This effects all the configuration specified in @var{file}: user
26147 accounts, system services, global package list, setuid programs, etc.
26148 The command starts system services specified in @var{file} that are not
26149 currently running; if a service is currently running this command will
26150 arrange for it to be upgraded the next time it is stopped (e.g.@: by
26151 @code{herd stop X} or @code{herd restart X}).
26153 This command creates a new generation whose number is one greater than
26154 the current generation (as reported by @command{guix system
26155 list-generations}). If that generation already exists, it will be
26156 overwritten. This behavior mirrors that of @command{guix package}
26157 (@pxref{Invoking guix package}).
26159 It also adds a bootloader menu entry for the new OS configuration,
26160 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
26161 entries for older configurations to a submenu, allowing you to choose
26162 an older system generation at boot time should you need it.
26164 @cindex provenance tracking, of the operating system
26165 Upon completion, the new system is deployed under
26166 @file{/run/current-system}. This directory contains @dfn{provenance
26167 meta-data}: the list of channels in use (@pxref{Channels}) and
26168 @var{file} itself, when available. This information is useful should
26169 you later want to inspect how this particular generation was built.
26171 In fact, assuming @var{file} is self-contained, you can later rebuild
26172 generation @var{n} of your operating system with:
26175 guix time-machine \
26176 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
26177 system reconfigure \
26178 /var/guix/profiles/system-@var{n}-link/configuration.scm
26181 You can think of it as some sort of built-in version control! Your
26182 system is not just a binary artifact: @emph{it carries its own source}.
26183 @xref{Service Reference, @code{provenance-service-type}}, for more
26184 information on provenance tracking.
26186 @item switch-generation
26187 @cindex generations
26188 Switch to an existing system generation. This action atomically
26189 switches the system profile to the specified system generation. It
26190 also rearranges the system's existing bootloader menu entries. It
26191 makes the menu entry for the specified system generation the default,
26192 and it moves the entries for the other generatiors to a submenu, if
26193 supported by the bootloader being used. The next time the system
26194 boots, it will use the specified system generation.
26196 The bootloader itself is not being reinstalled when using this
26197 command. Thus, the installed bootloader is used with an updated
26198 configuration file.
26200 The target generation can be specified explicitly by its generation
26201 number. For example, the following invocation would switch to system
26205 guix system switch-generation 7
26208 The target generation can also be specified relative to the current
26209 generation with the form @code{+N} or @code{-N}, where @code{+3} means
26210 ``3 generations ahead of the current generation,'' and @code{-1} means
26211 ``1 generation prior to the current generation.'' When specifying a
26212 negative value such as @code{-1}, you must precede it with @code{--} to
26213 prevent it from being parsed as an option. For example:
26216 guix system switch-generation -- -1
26219 Currently, the effect of invoking this action is @emph{only} to switch
26220 the system profile to an existing generation and rearrange the
26221 bootloader menu entries. To actually start using the target system
26222 generation, you must reboot after running this action. In the future,
26223 it will be updated to do the same things as @command{reconfigure},
26224 like activating and deactivating services.
26226 This action will fail if the specified generation does not exist.
26229 @cindex rolling back
26230 Switch to the preceding system generation. The next time the system
26231 boots, it will use the preceding system generation. This is the inverse
26232 of @command{reconfigure}, and it is exactly the same as invoking
26233 @command{switch-generation} with an argument of @code{-1}.
26235 Currently, as with @command{switch-generation}, you must reboot after
26236 running this action to actually start using the preceding system
26239 @item delete-generations
26240 @cindex deleting system generations
26241 @cindex saving space
26242 Delete system generations, making them candidates for garbage collection
26243 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
26246 This works in the same way as @command{guix package --delete-generations}
26247 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
26248 arguments, all system generations but the current one are deleted:
26251 guix system delete-generations
26254 You can also select the generations you want to delete. The example below
26255 deletes all the system generations that are more than two month old:
26258 guix system delete-generations 2m
26261 Running this command automatically reinstalls the bootloader with an updated
26262 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
26263 longer lists the generations that have been deleted.
26266 Build the derivation of the operating system, which includes all the
26267 configuration files and programs needed to boot and run the system.
26268 This action does not actually install anything.
26271 Populate the given directory with all the files necessary to run the
26272 operating system specified in @var{file}. This is useful for first-time
26273 installations of Guix System. For instance:
26276 guix system init my-os-config.scm /mnt
26279 copies to @file{/mnt} all the store items required by the configuration
26280 specified in @file{my-os-config.scm}. This includes configuration
26281 files, packages, and so on. It also creates other essential files
26282 needed for the system to operate correctly---e.g., the @file{/etc},
26283 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
26285 This command also installs bootloader on the target specified in
26286 @file{my-os-config}, unless the @option{--no-bootloader} option was
26290 @cindex virtual machine
26292 @anchor{guix system vm}
26293 Build a virtual machine that contains the operating system declared in
26294 @var{file}, and return a script to run that virtual machine (VM).
26297 The @code{vm} action and others below
26298 can use KVM support in the Linux-libre kernel. Specifically, if the
26299 machine has hardware virtualization support, the corresponding
26300 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
26301 must exist and be readable and writable by the user and by the
26302 build users of the daemon (@pxref{Build Environment Setup}).
26305 Arguments given to the script are passed to QEMU as in the example
26306 below, which enables networking and requests 1@tie{}GiB of RAM for the
26310 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
26313 The VM shares its store with the host system.
26315 Additional file systems can be shared between the host and the VM using
26316 the @code{--share} and @code{--expose} command-line options: the former
26317 specifies a directory to be shared with write access, while the latter
26318 provides read-only access to the shared directory.
26320 The example below creates a VM in which the user's home directory is
26321 accessible read-only, and where the @file{/exchange} directory is a
26322 read-write mapping of @file{$HOME/tmp} on the host:
26325 guix system vm my-config.scm \
26326 --expose=$HOME --share=$HOME/tmp=/exchange
26329 On GNU/Linux, the default is to boot directly to the kernel; this has
26330 the advantage of requiring only a very tiny root disk image since the
26331 store of the host can then be mounted.
26333 The @code{--full-boot} option forces a complete boot sequence, starting
26334 with the bootloader. This requires more disk space since a root image
26335 containing at least the kernel, initrd, and bootloader data files must
26336 be created. The @code{--image-size} option can be used to specify the
26339 @cindex System images, creation in various formats
26340 @cindex Creating system images in various formats
26343 @itemx docker-image
26344 Return a virtual machine, disk image, or Docker image of the operating
26345 system declared in @var{file} that stands alone. By default,
26346 @command{guix system} estimates the size of the image needed to store
26347 the system, but you can use the @option{--image-size} option to specify
26348 a value. Docker images are built to contain exactly what they need, so
26349 the @option{--image-size} option is ignored in the case of
26350 @code{docker-image}.
26352 You can specify the root file system type by using the
26353 @option{--file-system-type} option. It defaults to @code{ext4}.
26355 When using @code{vm-image}, the returned image is in qcow2 format, which
26356 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
26357 for more information on how to run the image in a virtual machine.
26359 When using @code{disk-image}, a raw disk image is produced; it can be
26360 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
26361 the device corresponding to a USB stick, one can copy the image to it
26362 using the following command:
26365 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
26368 When using @code{docker-image}, a Docker image is produced. Guix builds
26369 the image from scratch, not from a pre-existing Docker base image. As a
26370 result, it contains @emph{exactly} what you define in the operating
26371 system configuration file. You can then load the image and launch a
26372 Docker container using commands like the following:
26375 image_id="`docker load < guix-system-docker-image.tar.gz`"
26376 container_id="`docker create $image_id`"
26377 docker start $container_id
26380 This command starts a new Docker container from the specified image. It
26381 will boot the Guix system in the usual manner, which means it will
26382 start any services you have defined in the operating system
26383 configuration. You can get an interactive shell running in the container
26384 using @command{docker exec}:
26387 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
26390 Depending on what you run in the Docker container, it
26391 may be necessary to give the container additional permissions. For
26392 example, if you intend to build software using Guix inside of the Docker
26393 container, you may need to pass the @option{--privileged} option to
26394 @code{docker create}.
26397 Return a script to run the operating system declared in @var{file}
26398 within a container. Containers are a set of lightweight isolation
26399 mechanisms provided by the kernel Linux-libre. Containers are
26400 substantially less resource-demanding than full virtual machines since
26401 the kernel, shared objects, and other resources can be shared with the
26402 host system; this also means they provide thinner isolation.
26404 Currently, the script must be run as root in order to support more than
26405 a single user and group. The container shares its store with the host
26408 As with the @code{vm} action (@pxref{guix system vm}), additional file
26409 systems to be shared between the host and container can be specified
26410 using the @option{--share} and @option{--expose} options:
26413 guix system container my-config.scm \
26414 --expose=$HOME --share=$HOME/tmp=/exchange
26418 This option requires Linux-libre 3.19 or newer.
26423 @var{options} can contain any of the common build options (@pxref{Common
26424 Build Options}). In addition, @var{options} can contain one of the
26428 @item --expression=@var{expr}
26429 @itemx -e @var{expr}
26430 Consider the operating-system @var{expr} evaluates to.
26431 This is an alternative to specifying a file which evaluates to an
26433 This is used to generate the Guix system installer @pxref{Building the
26434 Installation Image}).
26436 @item --system=@var{system}
26437 @itemx -s @var{system}
26438 Attempt to build for @var{system} instead of the host system type.
26439 This works as per @command{guix build} (@pxref{Invoking guix build}).
26443 Return the derivation file name of the given operating system without
26446 @cindex provenance tracking, of the operating system
26447 @item --save-provenance
26448 As discussed above, @command{guix system init} and @command{guix system
26449 reconfigure} always save provenance information @i{via} a dedicated
26450 service (@pxref{Service Reference, @code{provenance-service-type}}).
26451 However, other commands don't do that by default. If you wish to, say,
26452 create a virtual machine image that contains provenance information, you
26456 guix system vm-image --save-provenance config.scm
26459 That way, the resulting image will effectively ``embed its own source''
26460 in the form of meta-data in @file{/run/current-system}. With that
26461 information, one can rebuild the image to make sure it really contains
26462 what it pretends to contain; or they could use that to derive a variant
26465 @item --file-system-type=@var{type}
26466 @itemx -t @var{type}
26467 For the @code{disk-image} action, create a file system of the given
26468 @var{type} on the image.
26470 When this option is omitted, @command{guix system} uses @code{ext4}.
26472 @cindex ISO-9660 format
26473 @cindex CD image format
26474 @cindex DVD image format
26475 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
26476 for burning on CDs and DVDs.
26478 @item --image-size=@var{size}
26479 For the @code{vm-image} and @code{disk-image} actions, create an image
26480 of the given @var{size}. @var{size} may be a number of bytes, or it may
26481 include a unit as a suffix (@pxref{Block size, size specifications,,
26482 coreutils, GNU Coreutils}).
26484 When this option is omitted, @command{guix system} computes an estimate
26485 of the image size as a function of the size of the system declared in
26490 For the @code{container} action, allow containers to access the host network,
26491 that is, do not create a network namespace.
26493 @item --root=@var{file}
26494 @itemx -r @var{file}
26495 Make @var{file} a symlink to the result, and register it as a garbage
26498 @item --skip-checks
26499 Skip pre-installation safety checks.
26501 By default, @command{guix system init} and @command{guix system
26502 reconfigure} perform safety checks: they make sure the file systems that
26503 appear in the @code{operating-system} declaration actually exist
26504 (@pxref{File Systems}), and that any Linux kernel modules that may be
26505 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
26506 RAM Disk}). Passing this option skips these tests altogether.
26509 @cindex on-error strategy
26510 @cindex error strategy
26511 @item --on-error=@var{strategy}
26512 Apply @var{strategy} when an error occurs when reading @var{file}.
26513 @var{strategy} may be one of the following:
26516 @item nothing-special
26517 Report the error concisely and exit. This is the default strategy.
26520 Likewise, but also display a backtrace.
26523 Report the error and enter Guile's debugger. From there, you can run
26524 commands such as @code{,bt} to get a backtrace, @code{,locals} to
26525 display local variable values, and more generally inspect the state of the
26526 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
26527 a list of available debugging commands.
26531 Once you have built, configured, re-configured, and re-re-configured
26532 your Guix installation, you may find it useful to list the operating
26533 system generations available on disk---and that you can choose from the
26534 bootloader boot menu:
26539 Describe the current system generation: its file name, the kernel and
26540 bootloader used, etc., as well as provenance information when available.
26542 @item list-generations
26543 List a summary of each generation of the operating system available on
26544 disk, in a human-readable way. This is similar to the
26545 @option{--list-generations} option of @command{guix package}
26546 (@pxref{Invoking guix package}).
26548 Optionally, one can specify a pattern, with the same syntax that is used
26549 in @command{guix package --list-generations}, to restrict the list of
26550 generations displayed. For instance, the following command displays
26551 generations that are up to 10 days old:
26554 $ guix system list-generations 10d
26559 The @command{guix system} command has even more to offer! The following
26560 sub-commands allow you to visualize how your system services relate to
26563 @anchor{system-extension-graph}
26566 @item extension-graph
26567 Emit in Dot/Graphviz format to standard output the @dfn{service
26568 extension graph} of the operating system defined in @var{file}
26569 (@pxref{Service Composition}, for more information on service
26575 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
26578 produces a PDF file showing the extension relations among services.
26580 @anchor{system-shepherd-graph}
26581 @item shepherd-graph
26582 Emit in Dot/Graphviz format to standard output the @dfn{dependency
26583 graph} of shepherd services of the operating system defined in
26584 @var{file}. @xref{Shepherd Services}, for more information and for an
26589 @node Invoking guix deploy
26590 @section Invoking @code{guix deploy}
26592 We've already seen @code{operating-system} declarations used to manage a
26593 machine's configuration locally. Suppose you need to configure multiple
26594 machines, though---perhaps you're managing a service on the web that's
26595 comprised of several servers. @command{guix deploy} enables you to use those
26596 same @code{operating-system} declarations to manage multiple remote hosts at
26597 once as a logical ``deployment''.
26600 The functionality described in this section is still under development
26601 and is subject to change. Get in touch with us on
26602 @email{guix-devel@@gnu.org}!
26606 guix deploy @var{file}
26609 Such an invocation will deploy the machines that the code within @var{file}
26610 evaluates to. As an example, @var{file} might contain a definition like this:
26613 ;; This is a Guix deployment of a "bare bones" setup, with
26614 ;; no X11 display server, to a machine with an SSH daemon
26615 ;; listening on localhost:2222. A configuration such as this
26616 ;; may be appropriate for virtual machine with ports
26617 ;; forwarded to the host's loopback interface.
26619 (use-service-modules networking ssh)
26620 (use-package-modules bootloaders)
26624 (host-name "gnu-deployed")
26625 (timezone "Etc/UTC")
26626 (bootloader (bootloader-configuration
26627 (bootloader grub-bootloader)
26628 (target "/dev/vda")
26629 (terminal-outputs '(console))))
26630 (file-systems (cons (file-system
26632 (device "/dev/vda1")
26634 %base-file-systems))
26636 (append (list (service dhcp-client-service-type)
26637 (service openssh-service-type
26638 (openssh-configuration
26639 (permit-root-login #t)
26640 (allow-empty-passwords? #t))))
26644 (operating-system %system)
26645 (environment managed-host-environment-type)
26646 (configuration (machine-ssh-configuration
26647 (host-name "localhost")
26648 (system "x86_64-linux")
26650 (identity "./id_rsa")
26654 The file should evaluate to a list of @var{machine} objects. This example,
26655 upon being deployed, will create a new generation on the remote system
26656 realizing the @code{operating-system} declaration @var{%system}.
26657 @var{environment} and @var{configuration} specify how the machine should be
26658 provisioned---that is, how the computing resources should be created and
26659 managed. The above example does not create any resources, as a
26660 @code{'managed-host} is a machine that is already running the Guix system and
26661 available over the network. This is a particularly simple case; a more
26662 complex deployment may involve, for example, starting virtual machines through
26663 a Virtual Private Server (VPS) provider. In such a case, a different
26664 @var{environment} type would be used.
26666 Do note that you first need to generate a key pair on the coordinator machine
26667 to allow the daemon to export signed archives of files from the store
26668 (@pxref{Invoking guix archive}).
26671 # guix archive --generate-key
26675 Each target machine must authorize the key of the master machine so that it
26676 accepts store items it receives from the coordinator:
26679 # guix archive --authorize < coordinator-public-key.txt
26682 @code{user}, in this example, specifies the name of the user account to log in
26683 as to perform the deployment. Its default value is @code{root}, but root
26684 login over SSH may be forbidden in some cases. To work around this,
26685 @command{guix deploy} can log in as an unprivileged user and employ
26686 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
26687 currently installed on the remote and can be invoked non-interactively as
26688 @code{user}. That is: the line in @code{sudoers} granting @code{user} the
26689 ability to use @code{sudo} must contain the @code{NOPASSWD} tag.
26691 @deftp {Data Type} machine
26692 This is the data type representing a single machine in a heterogeneous Guix
26696 @item @code{operating-system}
26697 The object of the operating system configuration to deploy.
26699 @item @code{environment}
26700 An @code{environment-type} describing how the machine should be provisioned.
26702 @item @code{configuration} (default: @code{#f})
26703 An object describing the configuration for the machine's @code{environment}.
26704 If the @code{environment} has a default configuration, @code{#f} may be used.
26705 If @code{#f} is used for an environment with no default configuration,
26706 however, an error will be thrown.
26710 @deftp {Data Type} machine-ssh-configuration
26711 This is the data type representing the SSH client parameters for a machine
26712 with an @code{environment} of @code{managed-host-environment-type}.
26715 @item @code{host-name}
26716 @item @code{build-locally?} (default: @code{#t})
26717 If false, system derivations will be built on the machine being deployed to.
26718 @item @code{system}
26719 The system type describing the architecture of the machine being deployed
26720 to---e.g., @code{"x86_64-linux"}.
26721 @item @code{authorize?} (default: @code{#t})
26722 If true, the coordinator's signing key will be added to the remote's ACL
26724 @item @code{port} (default: @code{22})
26725 @item @code{user} (default: @code{"root"})
26726 @item @code{identity} (default: @code{#f})
26727 If specified, the path to the SSH private key to use to authenticate with the
26730 @item @code{host-key} (default: @code{#f})
26731 This should be the SSH host key of the machine, which looks like this:
26734 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
26737 When @code{host-key} is @code{#f}, the server is authenticated against
26738 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
26744 @deftp {Data Type} digital-ocean-configuration
26745 This is the data type describing the Droplet that should be created for a
26746 machine with an @code{environment} of @code{digital-ocean-environment-type}.
26749 @item @code{ssh-key}
26750 The path to the SSH private key to use to authenticate with the remote
26751 host. In the future, this field may not exist.
26753 A list of string ``tags'' that uniquely identify the machine. Must be given
26754 such that no two machines in the deployment have the same set of tags.
26755 @item @code{region}
26756 A Digital Ocean region slug, such as @code{"nyc3"}.
26758 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
26759 @item @code{enable-ipv6?}
26760 Whether or not the droplet should be created with IPv6 networking.
26764 @node Running Guix in a VM
26765 @section Running Guix in a Virtual Machine
26767 @cindex virtual machine
26768 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
26770 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
26771 This image is a compressed image in QCOW format. You will first need to
26772 decompress with @command{xz -d}, and then you can pass it to an emulator such
26773 as QEMU (see below for details).
26775 This image boots the Xfce graphical environment and it contains some
26776 commonly-used tools. You can install more software in the image by running
26777 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
26778 also reconfigure the system based on its initial configuration file available
26779 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
26781 Instead of using this pre-built image, one can also build their own virtual
26782 machine image using @command{guix system vm-image} (@pxref{Invoking guix
26783 system}). The returned image is in qcow2 format, which the
26784 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
26787 If you built your own image, you must copy it out of the store
26788 (@pxref{The Store}) and give yourself permission to write to the copy
26789 before you can use it. When invoking QEMU, you must choose a system
26790 emulator that is suitable for your hardware platform. Here is a minimal
26791 QEMU invocation that will boot the result of @command{guix system
26792 vm-image} on x86_64 hardware:
26795 $ qemu-system-x86_64 \
26796 -nic user,model=virtio-net-pci \
26797 -enable-kvm -m 1024 \
26798 -device virtio-blk,drive=myhd \
26799 -drive if=none,file=/tmp/qemu-image,id=myhd
26802 Here is what each of these options means:
26805 @item qemu-system-x86_64
26806 This specifies the hardware platform to emulate. This should match the
26809 @item -nic user,model=virtio-net-pci
26810 Enable the unprivileged user-mode network stack. The guest OS can
26811 access the host but not vice versa. This is the simplest way to get the
26812 guest OS online. @code{model} specifies which network device to emulate:
26813 @code{virtio-net-pci} is a special device made for virtualized operating
26814 systems and recommended for most uses. Assuming your hardware platform is
26815 x86_64, you can get a list of available NIC models by running
26816 @command{qemu-system-x86_64 -nic model=help}.
26819 If your system has hardware virtualization extensions, enabling the
26820 virtual machine support (KVM) of the Linux kernel will make things run
26823 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
26825 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
26826 which may be insufficient for some operations.
26828 @item -device virtio-blk,drive=myhd
26829 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
26830 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
26831 better performance than if it were emulating a complete disk drive. See the
26832 QEMU and KVM documentation for more info.
26834 @item -drive if=none,file=/tmp/qemu-image,id=myhd
26835 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
26836 the ``myhd'' drive.
26839 The default @command{run-vm.sh} script that is returned by an invocation of
26840 @command{guix system vm} does not add a @command{-nic user} flag by default.
26841 To get network access from within the vm add the @code{(dhcp-client-service)}
26842 to your system definition and start the VM using
26843 @command{`guix system vm config.scm` -nic user}. An important caveat of using
26844 @command{-nic user} for networking is that @command{ping} will not work, because
26845 it uses the ICMP protocol. You'll have to use a different command to check for
26846 network connectivity, for example @command{guix download}.
26848 @subsection Connecting Through SSH
26852 To enable SSH inside a VM you need to add an SSH server like
26853 @code{openssh-service-type} to your VM (@pxref{Networking Services,
26854 @code{openssh-service-type}}). In addition you need to forward the SSH port,
26855 22 by default, to the host. You can do this with
26858 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
26861 To connect to the VM you can run
26864 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
26867 The @command{-p} tells @command{ssh} the port you want to connect to.
26868 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
26869 every time you modify your @command{config.scm} file and the
26870 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
26871 connection to an unknown host every time you connect.
26873 @subsection Using @command{virt-viewer} with Spice
26875 As an alternative to the default @command{qemu} graphical client you can
26876 use the @command{remote-viewer} from the @command{virt-viewer} package. To
26877 connect pass the @command{-spice port=5930,disable-ticketing} flag to
26878 @command{qemu}. See previous section for further information on how to do this.
26880 Spice also allows you to do some nice stuff like share your clipboard with your
26881 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
26884 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
26885 -chardev spicevmc,name=vdagent,id=vdagent
26886 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
26887 name=com.redhat.spice.0
26890 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
26892 @node Defining Services
26893 @section Defining Services
26895 The previous sections show the available services and how one can combine
26896 them in an @code{operating-system} declaration. But how do we define
26897 them in the first place? And what is a service anyway?
26900 * Service Composition:: The model for composing services.
26901 * Service Types and Services:: Types and services.
26902 * Service Reference:: API reference.
26903 * Shepherd Services:: A particular type of service.
26906 @node Service Composition
26907 @subsection Service Composition
26911 Here we define a @dfn{service} as, broadly, something that extends the
26912 functionality of the operating system. Often a service is a process---a
26913 @dfn{daemon}---started when the system boots: a secure shell server, a
26914 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
26915 whose execution can be triggered by another daemon---e.g., an FTP server
26916 started by @command{inetd} or a D-Bus service activated by
26917 @command{dbus-daemon}. Occasionally, a service does not map to a
26918 daemon. For instance, the ``account'' service collects user accounts
26919 and makes sure they exist when the system runs; the ``udev'' service
26920 collects device management rules and makes them available to the eudev
26921 daemon; the @file{/etc} service populates the @file{/etc} directory
26924 @cindex service extensions
26925 Guix system services are connected by @dfn{extensions}. For instance, the
26926 secure shell service @emph{extends} the Shepherd---the
26927 initialization system, running as PID@tie{}1---by giving it the command
26928 lines to start and stop the secure shell daemon (@pxref{Networking
26929 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
26930 service by passing it its @file{.service} specification, and extends the
26931 udev service by passing it device management rules (@pxref{Desktop
26932 Services, @code{upower-service}}); the Guix daemon service extends the
26933 Shepherd by passing it the command lines to start and stop the daemon,
26934 and extends the account service by passing it a list of required build
26935 user accounts (@pxref{Base Services}).
26937 All in all, services and their ``extends'' relations form a directed
26938 acyclic graph (DAG). If we represent services as boxes and extensions
26939 as arrows, a typical system might provide something like this:
26941 @image{images/service-graph,,5in,Typical service extension graph.}
26943 @cindex system service
26944 At the bottom, we see the @dfn{system service}, which produces the
26945 directory containing everything to run and boot the system, as returned
26946 by the @command{guix system build} command. @xref{Service Reference},
26947 to learn about the other service types shown here.
26948 @xref{system-extension-graph, the @command{guix system extension-graph}
26949 command}, for information on how to generate this representation for a
26950 particular operating system definition.
26952 @cindex service types
26953 Technically, developers can define @dfn{service types} to express these
26954 relations. There can be any number of services of a given type on the
26955 system---for instance, a system running two instances of the GNU secure
26956 shell server (lsh) has two instances of @code{lsh-service-type}, with
26957 different parameters.
26959 The following section describes the programming interface for service
26960 types and services.
26962 @node Service Types and Services
26963 @subsection Service Types and Services
26965 A @dfn{service type} is a node in the DAG described above. Let us start
26966 with a simple example, the service type for the Guix build daemon
26967 (@pxref{Invoking guix-daemon}):
26970 (define guix-service-type
26974 (list (service-extension shepherd-root-service-type guix-shepherd-service)
26975 (service-extension account-service-type guix-accounts)
26976 (service-extension activation-service-type guix-activation)))
26977 (default-value (guix-configuration))))
26981 It defines three things:
26985 A name, whose sole purpose is to make inspection and debugging easier.
26988 A list of @dfn{service extensions}, where each extension designates the
26989 target service type and a procedure that, given the parameters of the
26990 service, returns a list of objects to extend the service of that type.
26992 Every service type has at least one service extension. The only
26993 exception is the @dfn{boot service type}, which is the ultimate service.
26996 Optionally, a default value for instances of this type.
26999 In this example, @code{guix-service-type} extends three services:
27002 @item shepherd-root-service-type
27003 The @code{guix-shepherd-service} procedure defines how the Shepherd
27004 service is extended. Namely, it returns a @code{<shepherd-service>}
27005 object that defines how @command{guix-daemon} is started and stopped
27006 (@pxref{Shepherd Services}).
27008 @item account-service-type
27009 This extension for this service is computed by @code{guix-accounts},
27010 which returns a list of @code{user-group} and @code{user-account}
27011 objects representing the build user accounts (@pxref{Invoking
27014 @item activation-service-type
27015 Here @code{guix-activation} is a procedure that returns a gexp, which is
27016 a code snippet to run at ``activation time''---e.g., when the service is
27020 A service of this type is instantiated like this:
27023 (service guix-service-type
27024 (guix-configuration
27026 (use-substitutes? #f)))
27029 The second argument to the @code{service} form is a value representing
27030 the parameters of this specific service instance.
27031 @xref{guix-configuration-type, @code{guix-configuration}}, for
27032 information about the @code{guix-configuration} data type. When the
27033 value is omitted, the default value specified by
27034 @code{guix-service-type} is used:
27037 (service guix-service-type)
27040 @code{guix-service-type} is quite simple because it extends other
27041 services but is not extensible itself.
27043 @c @subsubsubsection Extensible Service Types
27045 The service type for an @emph{extensible} service looks like this:
27048 (define udev-service-type
27049 (service-type (name 'udev)
27051 (list (service-extension shepherd-root-service-type
27052 udev-shepherd-service)))
27054 (compose concatenate) ;concatenate the list of rules
27055 (extend (lambda (config rules)
27057 (($ <udev-configuration> udev initial-rules)
27058 (udev-configuration
27059 (udev udev) ;the udev package to use
27060 (rules (append initial-rules rules)))))))))
27063 This is the service type for the
27064 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
27065 management daemon}. Compared to the previous example, in addition to an
27066 extension of @code{shepherd-root-service-type}, we see two new fields:
27070 This is the procedure to @dfn{compose} the list of extensions to
27071 services of this type.
27073 Services can extend the udev service by passing it lists of rules; we
27074 compose those extensions simply by concatenating them.
27077 This procedure defines how the value of the service is @dfn{extended} with
27078 the composition of the extensions.
27080 Udev extensions are composed into a list of rules, but the udev service
27081 value is itself a @code{<udev-configuration>} record. So here, we
27082 extend that record by appending the list of rules it contains to the
27083 list of contributed rules.
27086 This is a string giving an overview of the service type. The string can
27087 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
27088 @command{guix system search} command searches these strings and displays
27089 them (@pxref{Invoking guix system}).
27092 There can be only one instance of an extensible service type such as
27093 @code{udev-service-type}. If there were more, the
27094 @code{service-extension} specifications would be ambiguous.
27096 Still here? The next section provides a reference of the programming
27097 interface for services.
27099 @node Service Reference
27100 @subsection Service Reference
27102 We have seen an overview of service types (@pxref{Service Types and
27103 Services}). This section provides a reference on how to manipulate
27104 services and service types. This interface is provided by the
27105 @code{(gnu services)} module.
27107 @deffn {Scheme Procedure} service @var{type} [@var{value}]
27108 Return a new service of @var{type}, a @code{<service-type>} object (see
27109 below.) @var{value} can be any object; it represents the parameters of
27110 this particular service instance.
27112 When @var{value} is omitted, the default value specified by @var{type}
27113 is used; if @var{type} does not specify a default value, an error is
27116 For instance, this:
27119 (service openssh-service-type)
27123 is equivalent to this:
27126 (service openssh-service-type
27127 (openssh-configuration))
27130 In both cases the result is an instance of @code{openssh-service-type}
27131 with the default configuration.
27134 @deffn {Scheme Procedure} service? @var{obj}
27135 Return true if @var{obj} is a service.
27138 @deffn {Scheme Procedure} service-kind @var{service}
27139 Return the type of @var{service}---i.e., a @code{<service-type>} object.
27142 @deffn {Scheme Procedure} service-value @var{service}
27143 Return the value associated with @var{service}. It represents its
27147 Here is an example of how a service is created and manipulated:
27151 (service nginx-service-type
27152 (nginx-configuration
27154 (log-directory log-directory)
27155 (run-directory run-directory)
27156 (file config-file))))
27161 (eq? (service-kind s) nginx-service-type)
27165 The @code{modify-services} form provides a handy way to change the
27166 parameters of some of the services of a list such as
27167 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
27168 evaluates to a list of services. Of course, you could always use
27169 standard list combinators such as @code{map} and @code{fold} to do that
27170 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
27171 @code{modify-services} simply provides a more concise form for this
27174 @deffn {Scheme Syntax} modify-services @var{services} @
27175 (@var{type} @var{variable} => @var{body}) @dots{}
27177 Modify the services listed in @var{services} according to the given
27178 clauses. Each clause has the form:
27181 (@var{type} @var{variable} => @var{body})
27184 where @var{type} is a service type---e.g.,
27185 @code{guix-service-type}---and @var{variable} is an identifier that is
27186 bound within the @var{body} to the service parameters---e.g., a
27187 @code{guix-configuration} instance---of the original service of that
27190 The @var{body} should evaluate to the new service parameters, which will
27191 be used to configure the new service. This new service will replace the
27192 original in the resulting list. Because a service's service parameters
27193 are created using @code{define-record-type*}, you can write a succinct
27194 @var{body} that evaluates to the new service parameters by using the
27195 @code{inherit} feature that @code{define-record-type*} provides.
27197 @xref{Using the Configuration System}, for example usage.
27201 Next comes the programming interface for service types. This is
27202 something you want to know when writing new service definitions, but not
27203 necessarily when simply looking for ways to customize your
27204 @code{operating-system} declaration.
27206 @deftp {Data Type} service-type
27207 @cindex service type
27208 This is the representation of a @dfn{service type} (@pxref{Service Types
27213 This is a symbol, used only to simplify inspection and debugging.
27215 @item @code{extensions}
27216 A non-empty list of @code{<service-extension>} objects (see below).
27218 @item @code{compose} (default: @code{#f})
27219 If this is @code{#f}, then the service type denotes services that cannot
27220 be extended---i.e., services that do not receive ``values'' from other
27223 Otherwise, it must be a one-argument procedure. The procedure is called
27224 by @code{fold-services} and is passed a list of values collected from
27225 extensions. It may return any single value.
27227 @item @code{extend} (default: @code{#f})
27228 If this is @code{#f}, services of this type cannot be extended.
27230 Otherwise, it must be a two-argument procedure: @code{fold-services}
27231 calls it, passing it the initial value of the service as the first
27232 argument and the result of applying @code{compose} to the extension
27233 values as the second argument. It must return a value that is a valid
27234 parameter value for the service instance.
27237 @xref{Service Types and Services}, for examples.
27240 @deffn {Scheme Procedure} service-extension @var{target-type} @
27242 Return a new extension for services of type @var{target-type}.
27243 @var{compute} must be a one-argument procedure: @code{fold-services}
27244 calls it, passing it the value associated with the service that provides
27245 the extension; it must return a valid value for the target service.
27248 @deffn {Scheme Procedure} service-extension? @var{obj}
27249 Return true if @var{obj} is a service extension.
27252 Occasionally, you might want to simply extend an existing service. This
27253 involves creating a new service type and specifying the extension of
27254 interest, which can be verbose; the @code{simple-service} procedure
27255 provides a shorthand for this.
27257 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
27258 Return a service that extends @var{target} with @var{value}. This works
27259 by creating a singleton service type @var{name}, of which the returned
27260 service is an instance.
27262 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
27266 (simple-service 'my-mcron-job mcron-service-type
27267 #~(job '(next-hour (3)) "guix gc -F 2G"))
27271 At the core of the service abstraction lies the @code{fold-services}
27272 procedure, which is responsible for ``compiling'' a list of services
27273 down to a single directory that contains everything needed to boot and
27274 run the system---the directory shown by the @command{guix system build}
27275 command (@pxref{Invoking guix system}). In essence, it propagates
27276 service extensions down the service graph, updating each node parameters
27277 on the way, until it reaches the root node.
27279 @deffn {Scheme Procedure} fold-services @var{services} @
27280 [#:target-type @var{system-service-type}]
27281 Fold @var{services} by propagating their extensions down to the root of
27282 type @var{target-type}; return the root service adjusted accordingly.
27285 Lastly, the @code{(gnu services)} module also defines several essential
27286 service types, some of which are listed below.
27288 @defvr {Scheme Variable} system-service-type
27289 This is the root of the service graph. It produces the system directory
27290 as returned by the @command{guix system build} command.
27293 @defvr {Scheme Variable} boot-service-type
27294 The type of the ``boot service'', which produces the @dfn{boot script}.
27295 The boot script is what the initial RAM disk runs when booting.
27298 @defvr {Scheme Variable} etc-service-type
27299 The type of the @file{/etc} service. This service is used to create
27300 files under @file{/etc} and can be extended by
27301 passing it name/file tuples such as:
27304 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
27307 In this example, the effect would be to add an @file{/etc/issue} file
27308 pointing to the given file.
27311 @defvr {Scheme Variable} setuid-program-service-type
27312 Type for the ``setuid-program service''. This service collects lists of
27313 executable file names, passed as gexps, and adds them to the set of
27314 setuid-root programs on the system (@pxref{Setuid Programs}).
27317 @defvr {Scheme Variable} profile-service-type
27318 Type of the service that populates the @dfn{system profile}---i.e., the
27319 programs under @file{/run/current-system/profile}. Other services can
27320 extend it by passing it lists of packages to add to the system profile.
27323 @cindex provenance tracking, of the operating system
27324 @defvr {Scheme Variable} provenance-service-type
27325 This is the type of the service that records @dfn{provenance meta-data}
27326 in the system itself. It creates several files under
27327 @file{/run/current-system}:
27331 This is a ``channel file'' that can be passed to @command{guix pull -C}
27332 or @command{guix time-machine -C}, and which describes the channels used
27333 to build the system, if that information was available
27334 (@pxref{Channels}).
27336 @item configuration.scm
27337 This is the file that was passed as the value for this
27338 @code{provenance-service-type} service. By default, @command{guix
27339 system reconfigure} automatically passes the OS configuration file it
27340 received on the command line.
27343 This contains the same information as the two other files but in a
27344 format that is more readily processable.
27347 In general, these two pieces of information (channels and configuration
27348 file) are enough to reproduce the operating system ``from source''.
27351 This information is necessary to rebuild your operating system, but it
27352 is not always sufficient. In particular, @file{configuration.scm}
27353 itself is insufficient if it is not self-contained---if it refers to
27354 external Guile modules or to extra files. If you want
27355 @file{configuration.scm} to be self-contained, we recommend that modules
27356 or files it refers to be part of a channel.
27358 Besides, provenance meta-data is ``silent'' in the sense that it does
27359 not change the bits contained in your system, @emph{except for the
27360 meta-data bits themselves}. Two different OS configurations or sets of
27361 channels can lead to the same system, bit-for-bit; when
27362 @code{provenance-service-type} is used, these two systems will have
27363 different meta-data and thus different store file names, which makes
27364 comparison less trivial.
27367 This service is automatically added to your operating system
27368 configuration when you use @command{guix system reconfigure},
27369 @command{guix system init}, or @command{guix deploy}.
27372 @node Shepherd Services
27373 @subsection Shepherd Services
27375 @cindex shepherd services
27377 @cindex init system
27378 The @code{(gnu services shepherd)} module provides a way to define
27379 services managed by the GNU@tie{}Shepherd, which is the
27380 initialization system---the first process that is started when the
27381 system boots, also known as PID@tie{}1
27382 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
27384 Services in the Shepherd can depend on each other. For instance, the
27385 SSH daemon may need to be started after the syslog daemon has been
27386 started, which in turn can only happen once all the file systems have
27387 been mounted. The simple operating system defined earlier (@pxref{Using
27388 the Configuration System}) results in a service graph like this:
27390 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
27392 You can actually generate such a graph for any operating system
27393 definition using the @command{guix system shepherd-graph} command
27394 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
27396 The @code{%shepherd-root-service} is a service object representing
27397 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
27398 by passing it lists of @code{<shepherd-service>} objects.
27400 @deftp {Data Type} shepherd-service
27401 The data type representing a service managed by the Shepherd.
27404 @item @code{provision}
27405 This is a list of symbols denoting what the service provides.
27407 These are the names that may be passed to @command{herd start},
27408 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
27409 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
27410 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
27412 @item @code{requirement} (default: @code{'()})
27413 List of symbols denoting the Shepherd services this one depends on.
27415 @cindex one-shot services, for the Shepherd
27416 @item @code{one-shot?} (default: @code{#f})
27417 Whether this service is @dfn{one-shot}. One-shot services stop immediately
27418 after their @code{start} action has completed. @xref{Slots of services,,,
27419 shepherd, The GNU Shepherd Manual}, for more info.
27421 @item @code{respawn?} (default: @code{#t})
27422 Whether to restart the service when it stops, for instance when the
27423 underlying process dies.
27426 @itemx @code{stop} (default: @code{#~(const #f)})
27427 The @code{start} and @code{stop} fields refer to the Shepherd's
27428 facilities to start and stop processes (@pxref{Service De- and
27429 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
27430 G-expressions that get expanded in the Shepherd configuration file
27431 (@pxref{G-Expressions}).
27433 @item @code{actions} (default: @code{'()})
27434 @cindex actions, of Shepherd services
27435 This is a list of @code{shepherd-action} objects (see below) defining
27436 @dfn{actions} supported by the service, in addition to the standard
27437 @code{start} and @code{stop} actions. Actions listed here become available as
27438 @command{herd} sub-commands:
27441 herd @var{action} @var{service} [@var{arguments}@dots{}]
27444 @item @code{auto-start?} (default: @code{#t})
27445 Whether this service should be started automatically by the Shepherd. If it
27446 is @code{#f} the service has to be started manually with @code{herd start}.
27448 @item @code{documentation}
27449 A documentation string, as shown when running:
27452 herd doc @var{service-name}
27455 where @var{service-name} is one of the symbols in @code{provision}
27456 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
27458 @item @code{modules} (default: @code{%default-modules})
27459 This is the list of modules that must be in scope when @code{start} and
27460 @code{stop} are evaluated.
27465 @deftp {Data Type} shepherd-action
27466 This is the data type that defines additional actions implemented by a
27467 Shepherd service (see above).
27471 Symbol naming the action.
27473 @item documentation
27474 This is a documentation string for the action. It can be viewed by running:
27477 herd doc @var{service} action @var{action}
27481 This should be a gexp that evaluates to a procedure of at least one argument,
27482 which is the ``running value'' of the service (@pxref{Slots of services,,,
27483 shepherd, The GNU Shepherd Manual}).
27486 The following example defines an action called @code{say-hello} that kindly
27492 (documentation "Say hi!")
27493 (procedure #~(lambda (running . args)
27494 (format #t "Hello, friend! arguments: ~s\n"
27499 Assuming this action is added to the @code{example} service, then you can do:
27502 # herd say-hello example
27503 Hello, friend! arguments: ()
27504 # herd say-hello example a b c
27505 Hello, friend! arguments: ("a" "b" "c")
27508 This, as you can see, is a fairly sophisticated way to say hello.
27509 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
27513 @defvr {Scheme Variable} shepherd-root-service-type
27514 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
27516 This is the service type that extensions target when they want to create
27517 shepherd services (@pxref{Service Types and Services}, for an example).
27518 Each extension must pass a list of @code{<shepherd-service>}.
27521 @defvr {Scheme Variable} %shepherd-root-service
27522 This service represents PID@tie{}1.
27526 @node Documentation
27527 @chapter Documentation
27529 @cindex documentation, searching for
27530 @cindex searching for documentation
27531 @cindex Info, documentation format
27533 @cindex manual pages
27534 In most cases packages installed with Guix come with documentation.
27535 There are two main documentation formats: ``Info'', a browseable
27536 hypertext format used for GNU software, and ``manual pages'' (or ``man
27537 pages''), the linear documentation format traditionally found on Unix.
27538 Info manuals are accessed with the @command{info} command or with Emacs,
27539 and man pages are accessed using @command{man}.
27541 You can look for documentation of software installed on your system by
27542 keyword. For example, the following command searches for information
27543 about ``TLS'' in Info manuals:
27547 "(emacs)Network Security" -- STARTTLS
27548 "(emacs)Network Security" -- TLS
27549 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
27550 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
27555 The command below searches for the same keyword in man pages:
27559 SSL (7) - OpenSSL SSL/TLS library
27560 certtool (1) - GnuTLS certificate tool
27564 These searches are purely local to your computer so you have the
27565 guarantee that documentation you find corresponds to what you have
27566 actually installed, you can access it off-line, and your privacy is
27569 Once you have these results, you can view the relevant documentation by
27573 $ info "(gnutls)Core TLS API"
27583 Info manuals contain sections and indices as well as hyperlinks like
27584 those found in Web pages. The @command{info} reader (@pxref{Top, Info
27585 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
27586 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
27587 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
27588 Introduction}, for an introduction to Info navigation.
27590 @node Installing Debugging Files
27591 @chapter Installing Debugging Files
27593 @cindex debugging files
27594 Program binaries, as produced by the GCC compilers for instance, are
27595 typically written in the ELF format, with a section containing
27596 @dfn{debugging information}. Debugging information is what allows the
27597 debugger, GDB, to map binary code to source code; it is required to
27598 debug a compiled program in good conditions.
27600 The problem with debugging information is that is takes up a fair amount
27601 of disk space. For example, debugging information for the GNU C Library
27602 weighs in at more than 60 MiB. Thus, as a user, keeping all the
27603 debugging info of all the installed programs is usually not an option.
27604 Yet, space savings should not come at the cost of an impediment to
27605 debugging---especially in the GNU system, which should make it easier
27606 for users to exert their computing freedom (@pxref{GNU Distribution}).
27608 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
27609 mechanism that allows users to get the best of both worlds: debugging
27610 information can be stripped from the binaries and stored in separate
27611 files. GDB is then able to load debugging information from those files,
27612 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
27615 The GNU distribution takes advantage of this by storing debugging
27616 information in the @code{lib/debug} sub-directory of a separate package
27617 output unimaginatively called @code{debug} (@pxref{Packages with
27618 Multiple Outputs}). Users can choose to install the @code{debug} output
27619 of a package when they need it. For instance, the following command
27620 installs the debugging information for the GNU C Library and for GNU
27624 guix install glibc:debug guile:debug
27627 GDB must then be told to look for debug files in the user's profile, by
27628 setting the @code{debug-file-directory} variable (consider setting it
27629 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
27633 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
27636 From there on, GDB will pick up debugging information from the
27637 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
27639 In addition, you will most likely want GDB to be able to show the source
27640 code being debugged. To do that, you will have to unpack the source
27641 code of the package of interest (obtained with @code{guix build
27642 --source}, @pxref{Invoking guix build}), and to point GDB to that source
27643 directory using the @code{directory} command (@pxref{Source Path,
27644 @code{directory},, gdb, Debugging with GDB}).
27646 @c XXX: keep me up-to-date
27647 The @code{debug} output mechanism in Guix is implemented by the
27648 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
27649 opt-in---debugging information is available only for the packages
27650 with definitions explicitly declaring a @code{debug} output. This may be
27651 changed to opt-out in the future if our build farm servers can handle
27652 the load. To check whether a package has a @code{debug} output, use
27653 @command{guix package --list-available} (@pxref{Invoking guix package}).
27656 @node Security Updates
27657 @chapter Security Updates
27659 @cindex security updates
27660 @cindex security vulnerabilities
27661 Occasionally, important security vulnerabilities are discovered in software
27662 packages and must be patched. Guix developers try hard to keep track of
27663 known vulnerabilities and to apply fixes as soon as possible in the
27664 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
27665 containing only security updates.) The @command{guix lint} tool helps
27666 developers find out about vulnerable versions of software packages in the
27671 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
27672 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
27673 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
27677 @xref{Invoking guix lint}, for more information.
27679 Guix follows a functional
27680 package management discipline (@pxref{Introduction}), which implies
27681 that, when a package is changed, @emph{every package that depends on it}
27682 must be rebuilt. This can significantly slow down the deployment of
27683 fixes in core packages such as libc or Bash, since basically the whole
27684 distribution would need to be rebuilt. Using pre-built binaries helps
27685 (@pxref{Substitutes}), but deployment may still take more time than
27689 To address this, Guix implements @dfn{grafts}, a mechanism that allows
27690 for fast deployment of critical updates without the costs associated
27691 with a whole-distribution rebuild. The idea is to rebuild only the
27692 package that needs to be patched, and then to ``graft'' it onto packages
27693 explicitly installed by the user and that were previously referring to
27694 the original package. The cost of grafting is typically very low, and
27695 order of magnitudes lower than a full rebuild of the dependency chain.
27697 @cindex replacements of packages, for grafts
27698 For instance, suppose a security update needs to be applied to Bash.
27699 Guix developers will provide a package definition for the ``fixed''
27700 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
27701 Packages}). Then, the original package definition is augmented with a
27702 @code{replacement} field pointing to the package containing the bug fix:
27709 (replacement bash-fixed)))
27712 From there on, any package depending directly or indirectly on Bash---as
27713 reported by @command{guix gc --requisites} (@pxref{Invoking guix
27714 gc})---that is installed is automatically ``rewritten'' to refer to
27715 @code{bash-fixed} instead of @code{bash}. This grafting process takes
27716 time proportional to the size of the package, usually less than a
27717 minute for an ``average'' package on a recent machine. Grafting is
27718 recursive: when an indirect dependency requires grafting, then grafting
27719 ``propagates'' up to the package that the user is installing.
27721 Currently, the length of the name and version of the graft and that of
27722 the package it replaces (@code{bash-fixed} and @code{bash} in the example
27723 above) must be equal. This restriction mostly comes from the fact that
27724 grafting works by patching files, including binary files, directly.
27725 Other restrictions may apply: for instance, when adding a graft to a
27726 package providing a shared library, the original shared library and its
27727 replacement must have the same @code{SONAME} and be binary-compatible.
27729 The @option{--no-grafts} command-line option allows you to forcefully
27730 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
27734 guix build bash --no-grafts
27738 returns the store file name of the original Bash, whereas:
27745 returns the store file name of the ``fixed'', replacement Bash. This
27746 allows you to distinguish between the two variants of Bash.
27748 To verify which Bash your whole profile refers to, you can run
27749 (@pxref{Invoking guix gc}):
27752 guix gc -R `readlink -f ~/.guix-profile` | grep bash
27756 @dots{} and compare the store file names that you get with those above.
27757 Likewise for a complete Guix system generation:
27760 guix gc -R `guix system build my-config.scm` | grep bash
27763 Lastly, to check which Bash running processes are using, you can use the
27764 @command{lsof} command:
27767 lsof | grep /gnu/store/.*bash
27771 @node Bootstrapping
27772 @chapter Bootstrapping
27774 @c Adapted from the ELS 2013 paper.
27776 @cindex bootstrapping
27778 Bootstrapping in our context refers to how the distribution gets built
27779 ``from nothing''. Remember that the build environment of a derivation
27780 contains nothing but its declared inputs (@pxref{Introduction}). So
27781 there's an obvious chicken-and-egg problem: how does the first package
27782 get built? How does the first compiler get compiled? Note that this is
27783 a question of interest only to the curious hacker, not to the regular
27784 user, so you can shamelessly skip this section if you consider yourself
27785 a ``regular user''.
27787 @cindex bootstrap binaries
27788 The GNU system is primarily made of C code, with libc at its core. The
27789 GNU build system itself assumes the availability of a Bourne shell and
27790 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
27791 `grep'. Furthermore, build programs---programs that run
27792 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
27793 (@pxref{Derivations}). Consequently, to be able to build anything at
27794 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
27795 Binutils, libc, and the other packages mentioned above---the
27796 @dfn{bootstrap binaries}.
27798 These bootstrap binaries are ``taken for granted'', though we can also
27799 re-create them if needed (more on that later).
27801 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
27802 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
27805 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
27806 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
27809 @node Reduced Binary Seed Bootstrap
27810 @section The Reduced Binary Seed Bootstrap
27812 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
27813 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
27814 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
27815 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
27816 ``taken for granted.''
27818 Taking these binaries for granted means that we consider them to be a correct
27819 and trustworthy `seed' for building the complete system. Therein lies a
27820 problem: the current combined size of these bootstrap binaries is about 250MB
27821 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
27822 these is next to impossible.
27824 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
27825 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
27826 Bootstrap'' and while we are working towards that goal it would be hyperbole
27827 to use that term for what we do now.}.
27829 The Reduced Binary Seed bootstrap removes the most critical tools---from a
27830 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
27831 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
27832 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
27833 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
27834 these new binary seeds and a new set of
27836 packages@footnote{@c
27851 gcc-mesboot1-wrapper,
27852 glibc-headers-mesboot,
27856 gcc-mesboot-wrapper.
27859 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
27860 From here on the more traditional bootstrap process resumes. This approach
27861 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
27862 reduce this further. If you are interested, join us on @code{#bootstrappable}
27863 on the Freenode IRC network.
27865 @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
27866 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
27868 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
27869 compiler used to build the rest of GuixSD.
27871 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
27873 @node Preparing to Use the Bootstrap Binaries
27874 @section Preparing to Use the Bootstrap Binaries
27876 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
27877 @c large image, it's hard to scroll. Oh well.
27878 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
27880 The figure above shows the very beginning of the dependency graph of the
27881 distribution, corresponding to the package definitions of the @code{(gnu
27882 packages bootstrap)} module. A similar figure can be generated with
27883 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
27886 guix graph -t derivation \
27887 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
27888 | dot -Tps > gcc.ps
27891 or, for the Reduced Binary Seed bootstrap
27894 guix graph -t derivation \
27895 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
27896 | dot -Tps > mes.ps
27899 At this level of detail, things are
27900 slightly complex. First, Guile itself consists of an ELF executable,
27901 along with many source and compiled Scheme files that are dynamically
27902 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
27903 tarball shown in this graph. This tarball is part of Guix's ``source''
27904 distribution, and gets inserted into the store with @code{add-to-store}
27905 (@pxref{The Store}).
27907 But how do we write a derivation that unpacks this tarball and adds it
27908 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
27909 derivation---the first one that gets built---uses @code{bash} as its
27910 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
27911 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
27912 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
27913 the Guix source distribution, whose sole purpose is to allow the Guile
27914 tarball to be unpacked.
27916 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
27917 Guile that can be used to run subsequent build programs. Its first task
27918 is to download tarballs containing the other pre-built binaries---this
27919 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
27920 @code{ftp-client.scm} are used for this purpose. The
27921 @code{module-import.drv} derivations import those modules in a directory
27922 in the store, using the original layout. The
27923 @code{module-import-compiled.drv} derivations compile those modules, and
27924 write them in an output directory with the right layout. This
27925 corresponds to the @code{#:modules} argument of
27926 @code{build-expression->derivation} (@pxref{Derivations}).
27928 Finally, the various tarballs are unpacked by the derivations
27929 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
27930 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
27931 point we have a working C tool chain.
27933 @unnumberedsec Building the Build Tools
27935 Bootstrapping is complete when we have a full tool chain that does not
27936 depend on the pre-built bootstrap tools discussed above. This
27937 no-dependency requirement is verified by checking whether the files of
27938 the final tool chain contain references to the @file{/gnu/store}
27939 directories of the bootstrap inputs. The process that leads to this
27940 ``final'' tool chain is described by the package definitions found in
27941 the @code{(gnu packages commencement)} module.
27943 The @command{guix graph} command allows us to ``zoom out'' compared to
27944 the graph above, by looking at the level of package objects instead of
27945 individual derivations---remember that a package may translate to
27946 several derivations, typically one derivation to download its source,
27947 one to build the Guile modules it needs, and one to actually build the
27948 package from source. The command:
27951 guix graph -t bag \
27952 -e '(@@@@ (gnu packages commencement)
27953 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
27957 produces the dependency graph leading to the ``final'' C
27958 library@footnote{You may notice the @code{glibc-intermediate} label,
27959 suggesting that it is not @emph{quite} final, but as a good
27960 approximation, we will consider it final.}, depicted below.
27962 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
27964 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
27965 The first tool that gets built with the bootstrap binaries is
27966 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
27967 for all the following packages. From there Findutils and Diffutils get
27970 Then come the first-stage Binutils and GCC, built as pseudo cross
27971 tools---i.e., with @code{--target} equal to @code{--host}. They are
27972 used to build libc. Thanks to this cross-build trick, this libc is
27973 guaranteed not to hold any reference to the initial tool chain.
27975 From there the final Binutils and GCC (not shown above) are built.
27977 from the final Binutils, and links programs against the just-built libc.
27978 This tool chain is used to build the other packages used by Guix and by
27979 the GNU Build System: Guile, Bash, Coreutils, etc.
27981 And voilà! At this point we have the complete set of build tools that
27982 the GNU Build System expects. These are in the @code{%final-inputs}
27983 variable of the @code{(gnu packages commencement)} module, and are
27984 implicitly used by any package that uses @code{gnu-build-system}
27985 (@pxref{Build Systems, @code{gnu-build-system}}).
27988 @unnumberedsec Building the Bootstrap Binaries
27990 @cindex bootstrap binaries
27991 Because the final tool chain does not depend on the bootstrap binaries,
27992 those rarely need to be updated. Nevertheless, it is useful to have an
27993 automated way to produce them, should an update occur, and this is what
27994 the @code{(gnu packages make-bootstrap)} module provides.
27996 The following command builds the tarballs containing the bootstrap binaries
27997 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
27998 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
27999 and Guile, and a tarball containing a mixture of Coreutils and other basic
28000 command-line tools):
28003 guix build bootstrap-tarballs
28006 The generated tarballs are those that should be referred to in the
28007 @code{(gnu packages bootstrap)} module mentioned at the beginning of
28010 Still here? Then perhaps by now you've started to wonder: when do we
28011 reach a fixed point? That is an interesting question! The answer is
28012 unknown, but if you would like to investigate further (and have
28013 significant computational and storage resources to do so), then let us
28016 @unnumberedsec Reducing the Set of Bootstrap Binaries
28018 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
28019 binary code! Why is that a problem? It's a problem because these big chunks
28020 of binary code are practically non-auditable, which makes it hard to establish
28021 what source code produced them. Every unauditable binary also leaves us
28022 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
28023 paper @emph{Reflections on Trusting Trust}.
28025 This is mitigated by the fact that our bootstrap binaries were generated
28026 from an earlier Guix revision. Nevertheless it lacks the level of
28027 transparency that we get in the rest of the package dependency graph,
28028 where Guix always gives us a source-to-binary mapping. Thus, our goal
28029 is to reduce the set of bootstrap binaries to the bare minimum.
28031 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
28032 on-going projects to do that. One of these is about replacing the
28033 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
28034 of increasing complexity, which could be built from source starting from
28035 a simple and auditable assembler.
28037 Our first major achievement is the replacement of of GCC, the GNU C Library
28038 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
28039 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
28040 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
28041 bootstrapped yet and thus we inject them as binary seeds. We call this the
28042 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
28043 binaries! Also, it has eliminated the C compiler binary; i686-linux and
28044 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
28046 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
28047 also looking at any other bootstrap binaries. Your help is welcome!
28050 @chapter Porting to a New Platform
28052 As discussed above, the GNU distribution is self-contained, and
28053 self-containment is achieved by relying on pre-built ``bootstrap
28054 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
28055 operating system kernel, CPU architecture, and application binary
28056 interface (ABI). Thus, to port the distribution to a platform that is
28057 not yet supported, one must build those bootstrap binaries, and update
28058 the @code{(gnu packages bootstrap)} module to use them on that platform.
28060 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
28061 When everything goes well, and assuming the GNU tool chain supports the
28062 target platform, this can be as simple as running a command like this
28066 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
28069 For this to work, the @code{glibc-dynamic-linker} procedure in
28070 @code{(gnu packages bootstrap)} must be augmented to return the right
28071 file name for libc's dynamic linker on that platform; likewise,
28072 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
28073 taught about the new platform.
28075 Once these are built, the @code{(gnu packages bootstrap)} module needs
28076 to be updated to refer to these binaries on the target platform. That
28077 is, the hashes and URLs of the bootstrap tarballs for the new platform
28078 must be added alongside those of the currently supported platforms. The
28079 bootstrap Guile tarball is treated specially: it is expected to be
28080 available locally, and @file{gnu/local.mk} has rules to download it for
28081 the supported architectures; a rule for the new platform must be added
28084 In practice, there may be some complications. First, it may be that the
28085 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
28086 above) is not recognized by all the GNU tools. Typically, glibc
28087 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
28088 configure flag (see @code{gcc.scm} for examples of how to handle this).
28089 Second, some of the required packages could fail to build for that
28090 platform. Lastly, the generated binaries could be broken for some
28093 @c *********************************************************************
28094 @include contributing.texi
28096 @c *********************************************************************
28097 @node Acknowledgments
28098 @chapter Acknowledgments
28100 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
28101 which was designed and
28102 implemented by Eelco Dolstra, with contributions from other people (see
28103 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
28104 management, and promoted unprecedented features, such as transactional
28105 package upgrades and rollbacks, per-user profiles, and referentially
28106 transparent build processes. Without this work, Guix would not exist.
28108 The Nix-based software distributions, Nixpkgs and NixOS, have also been
28109 an inspiration for Guix.
28111 GNU@tie{}Guix itself is a collective work with contributions from a
28112 number of people. See the @file{AUTHORS} file in Guix for more
28113 information on these fine people. The @file{THANKS} file lists people
28114 who have helped by reporting bugs, taking care of the infrastructure,
28115 providing artwork and themes, making suggestions, and more---thank you!
28118 @c *********************************************************************
28119 @node GNU Free Documentation License
28120 @appendix GNU Free Documentation License
28121 @cindex license, GNU Free Documentation License
28122 @include fdl-1.3.texi
28124 @c *********************************************************************
28125 @node Concept Index
28126 @unnumbered Concept Index
28129 @node Programming Index
28130 @unnumbered Programming Index
28131 @syncodeindex tp fn
28132 @syncodeindex vr fn
28137 @c Local Variables:
28138 @c ispell-local-dictionary: "american";