6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017 Hartmut Goebel@*
51 Copyright @copyright{} 2017 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018 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@*
70 Permission is granted to copy, distribute and/or modify this document
71 under the terms of the GNU Free Documentation License, Version 1.3 or
72 any later version published by the Free Software Foundation; with no
73 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
74 copy of the license is included in the section entitled ``GNU Free
75 Documentation License''.
78 @dircategory System administration
80 * Guix: (guix). Manage installed software and system configuration.
81 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
82 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
83 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
84 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
85 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
88 @dircategory Software development
90 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
91 * guix build: (guix)Invoking guix build. Building packages.
92 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
96 @title GNU Guix Reference Manual
97 @subtitle Using the GNU Guix Functional Package Manager
98 @author The GNU Guix Developers
101 @vskip 0pt plus 1filll
102 Edition @value{EDITION} @*
110 @c *********************************************************************
114 This document describes GNU Guix version @value{VERSION}, a functional
115 package management tool written for the GNU system.
117 @c TRANSLATORS: You can replace the following paragraph with information on
118 @c how to join your own translation team and how to report issues with the
120 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
121 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
122 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
123 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
124 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
125 would like to translate it in your native language, consider joining the
126 @uref{https://translationproject.org/domain/guix-manual.html, Translation
130 * Introduction:: What is Guix about?
131 * Installation:: Installing Guix.
132 * System Installation:: Installing the whole operating system.
133 * Package Management:: Package installation, upgrade, etc.
134 * Development:: Guix-aided software development.
135 * Programming Interface:: Using Guix in Scheme.
136 * Utilities:: Package management commands.
137 * System Configuration:: Configuring the operating system.
138 * Documentation:: Browsing software user manuals.
139 * Installing Debugging Files:: Feeding the debugger.
140 * Security Updates:: Deploying security fixes quickly.
141 * Bootstrapping:: GNU/Linux built from scratch.
142 * Porting:: Targeting another platform or kernel.
143 * Contributing:: Your help needed!
145 * Acknowledgments:: Thanks!
146 * GNU Free Documentation License:: The license of this manual.
147 * Concept Index:: Concepts.
148 * Programming Index:: Data types, functions, and variables.
151 --- The Detailed Node Listing ---
155 * Managing Software the Guix Way:: What's special.
156 * GNU Distribution:: The packages and tools.
160 * Binary Installation:: Getting Guix running in no time!
161 * Requirements:: Software needed to build and run Guix.
162 * Running the Test Suite:: Testing Guix.
163 * Setting Up the Daemon:: Preparing the build daemon's environment.
164 * Invoking guix-daemon:: Running the build daemon.
165 * Application Setup:: Application-specific setup.
167 Setting Up the Daemon
169 * Build Environment Setup:: Preparing the isolated build environment.
170 * Daemon Offload Setup:: Offloading builds to remote machines.
171 * SELinux Support:: Using an SELinux policy for the daemon.
175 * Limitations:: What you can expect.
176 * Hardware Considerations:: Supported hardware.
177 * USB Stick and DVD Installation:: Preparing the installation medium.
178 * Preparing for Installation:: Networking, partitioning, etc.
179 * Guided Graphical Installation:: Easy graphical installation.
180 * Manual Installation:: Manual installation for wizards.
181 * After System Installation:: When installation succeeded.
182 * Installing Guix in a VM:: Guix System playground.
183 * Building the Installation Image:: How this comes to be.
187 * Keyboard Layout and Networking and Partitioning:: Initial setup.
188 * Proceeding with the Installation:: Installing.
192 * Features:: How Guix will make your life brighter.
193 * Invoking guix package:: Package installation, removal, etc.
194 * Substitutes:: Downloading pre-built binaries.
195 * Packages with Multiple Outputs:: Single source package, multiple outputs.
196 * Invoking guix gc:: Running the garbage collector.
197 * Invoking guix pull:: Fetching the latest Guix and distribution.
198 * Channels:: Customizing the package collection.
199 * Inferiors:: Interacting with another revision of Guix.
200 * Invoking guix describe:: Display information about your Guix revision.
201 * Invoking guix archive:: Exporting and importing store files.
205 * Official Substitute Server:: One particular source of substitutes.
206 * Substitute Server Authorization:: How to enable or disable substitutes.
207 * Substitute Authentication:: How Guix verifies substitutes.
208 * Proxy Settings:: How to get substitutes via proxy.
209 * Substitution Failure:: What happens when substitution fails.
210 * On Trusting Binaries:: How can you trust that binary blob?
214 * Invoking guix environment:: Setting up development environments.
215 * Invoking guix pack:: Creating software bundles.
217 Programming Interface
219 * Package Modules:: Packages from the programmer's viewpoint.
220 * Defining Packages:: Defining new packages.
221 * Build Systems:: Specifying how packages are built.
222 * The Store:: Manipulating the package store.
223 * Derivations:: Low-level interface to package derivations.
224 * The Store Monad:: Purely functional interface to the store.
225 * G-Expressions:: Manipulating build expressions.
226 * Invoking guix repl:: Fiddling with Guix interactively.
230 * package Reference:: The package data type.
231 * origin Reference:: The origin data type.
235 * Invoking guix build:: Building packages from the command line.
236 * Invoking guix edit:: Editing package definitions.
237 * Invoking guix download:: Downloading a file and printing its hash.
238 * Invoking guix hash:: Computing the cryptographic hash of a file.
239 * Invoking guix import:: Importing package definitions.
240 * Invoking guix refresh:: Updating package definitions.
241 * Invoking guix lint:: Finding errors in package definitions.
242 * Invoking guix size:: Profiling disk usage.
243 * Invoking guix graph:: Visualizing the graph of packages.
244 * Invoking guix publish:: Sharing substitutes.
245 * Invoking guix challenge:: Challenging substitute servers.
246 * Invoking guix copy:: Copying to and from a remote store.
247 * Invoking guix container:: Process isolation.
248 * Invoking guix weather:: Assessing substitute availability.
249 * Invoking guix processes:: Listing client processes.
251 Invoking @command{guix build}
253 * Common Build Options:: Build options for most commands.
254 * Package Transformation Options:: Creating variants of packages.
255 * Additional Build Options:: Options specific to 'guix build'.
256 * Debugging Build Failures:: Real life packaging experience.
260 * Using the Configuration System:: Customizing your GNU system.
261 * operating-system Reference:: Detail of operating-system declarations.
262 * File Systems:: Configuring file system mounts.
263 * Mapped Devices:: Block device extra processing.
264 * User Accounts:: Specifying user accounts.
265 * Keyboard Layout:: How the system interprets key strokes.
266 * Locales:: Language and cultural convention settings.
267 * Services:: Specifying system services.
268 * Setuid Programs:: Programs running with root privileges.
269 * X.509 Certificates:: Authenticating HTTPS servers.
270 * Name Service Switch:: Configuring libc's name service switch.
271 * Initial RAM Disk:: Linux-Libre bootstrapping.
272 * Bootloader Configuration:: Configuring the boot loader.
273 * Invoking guix system:: Instantiating a system configuration.
274 * Invoking guix deploy:: Deploying a system configuration to a remote host.
275 * Running Guix in a VM:: How to run Guix System in a virtual machine.
276 * Defining Services:: Adding new service definitions.
280 * Base Services:: Essential system services.
281 * Scheduled Job Execution:: The mcron service.
282 * Log Rotation:: The rottlog service.
283 * Networking Services:: Network setup, SSH daemon, etc.
284 * X Window:: Graphical display.
285 * Printing Services:: Local and remote printer support.
286 * Desktop Services:: D-Bus and desktop services.
287 * Sound Services:: ALSA and Pulseaudio services.
288 * Database Services:: SQL databases, key-value stores, etc.
289 * Mail Services:: IMAP, POP3, SMTP, and all that.
290 * Messaging Services:: Messaging services.
291 * Telephony Services:: Telephony services.
292 * Monitoring Services:: Monitoring services.
293 * Kerberos Services:: Kerberos services.
294 * Web Services:: Web servers.
295 * Certificate Services:: TLS certificates via Let's Encrypt.
296 * DNS Services:: DNS daemons.
297 * VPN Services:: VPN daemons.
298 * Network File System:: NFS related services.
299 * Continuous Integration:: The Cuirass service.
300 * Power Management Services:: Extending battery life.
301 * Audio Services:: The MPD.
302 * Virtualization Services:: Virtualization services.
303 * Version Control Services:: Providing remote access to Git repositories.
304 * Game Services:: Game servers.
305 * Miscellaneous Services:: Other services.
309 * Service Composition:: The model for composing services.
310 * Service Types and Services:: Types and services.
311 * Service Reference:: API reference.
312 * Shepherd Services:: A particular type of service.
317 @c *********************************************************************
319 @chapter Introduction
322 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
323 using the international phonetic alphabet (IPA).} is a package
324 management tool for and distribution of the GNU system.
325 Guix makes it easy for unprivileged
326 users to install, upgrade, or remove software packages, to roll back to a
327 previous package set, to build packages from source, and generally
328 assists with the creation and maintenance of software environments.
331 @cindex GuixSD, now Guix System
332 @cindex Guix System Distribution, now Guix System
333 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
334 complements the available tools without interference (@pxref{Installation}),
335 or you can use it as a standalone operating system distribution,
336 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
337 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
338 group everything under the ``Guix'' banner since, after all, Guix System is
339 readily available through the @command{guix system} command, even if you're
340 using a different distro underneath!}. @xref{GNU Distribution}.
343 * Managing Software the Guix Way:: What's special.
344 * GNU Distribution:: The packages and tools.
347 @node Managing Software the Guix Way
348 @section Managing Software the Guix Way
350 @cindex user interfaces
351 Guix provides a command-line package management interface
352 (@pxref{Package Management}), tools to help with software development
353 (@pxref{Development}), command-line utilities for more advanced usage,
354 (@pxref{Utilities}), as well as Scheme programming interfaces
355 (@pxref{Programming Interface}).
357 Its @dfn{build daemon} is responsible for building packages on behalf of
358 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
359 binaries from authorized sources (@pxref{Substitutes}).
361 @cindex extensibility of the distribution
362 @cindex customization, of packages
363 Guix includes package definitions for many GNU and non-GNU packages, all
364 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
365 user's computing freedom}. It is @emph{extensible}: users can write
366 their own package definitions (@pxref{Defining Packages}) and make them
367 available as independent package modules (@pxref{Package Modules}). It
368 is also @emph{customizable}: users can @emph{derive} specialized package
369 definitions from existing ones, including from the command line
370 (@pxref{Package Transformation Options}).
372 @cindex functional package management
374 Under the hood, Guix implements the @dfn{functional package management}
375 discipline pioneered by Nix (@pxref{Acknowledgments}).
376 In Guix, the package build and installation process is seen
377 as a @emph{function}, in the mathematical sense. That function takes inputs,
378 such as build scripts, a compiler, and libraries, and
379 returns an installed package. As a pure function, its result depends
380 solely on its inputs---for instance, it cannot refer to software or
381 scripts that were not explicitly passed as inputs. A build function
382 always produces the same result when passed a given set of inputs. It
383 cannot alter the environment of the running system in
384 any way; for instance, it cannot create, modify, or delete files outside
385 of its build and installation directories. This is achieved by running
386 build processes in isolated environments (or @dfn{containers}), where only their
387 explicit inputs are visible.
390 The result of package build functions is @dfn{cached} in the file
391 system, in a special directory called @dfn{the store} (@pxref{The
392 Store}). Each package is installed in a directory of its own in the
393 store---by default under @file{/gnu/store}. The directory name contains
394 a hash of all the inputs used to build that package; thus, changing an
395 input yields a different directory name.
397 This approach is the foundation for the salient features of Guix: support
398 for transactional package upgrade and rollback, per-user installation, and
399 garbage collection of packages (@pxref{Features}).
402 @node GNU Distribution
403 @section GNU Distribution
406 Guix comes with a distribution of the GNU system consisting entirely of
407 free software@footnote{The term ``free'' here refers to the
408 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
409 users of that software}.}. The
410 distribution can be installed on its own (@pxref{System Installation}),
411 but it is also possible to install Guix as a package manager on top of
412 an installed GNU/Linux system (@pxref{Installation}). When we need to
413 distinguish between the two, we refer to the standalone distribution as
416 The distribution provides core GNU packages such as GNU libc, GCC, and
417 Binutils, as well as many GNU and non-GNU applications. The complete
418 list of available packages can be browsed
419 @url{https://www.gnu.org/software/guix/packages,on-line} or by
420 running @command{guix package} (@pxref{Invoking guix package}):
423 guix package --list-available
426 Our goal is to provide a practical 100% free software distribution of
427 Linux-based and other variants of GNU, with a focus on the promotion and
428 tight integration of GNU components, and an emphasis on programs and
429 tools that help users exert that freedom.
431 Packages are currently available on the following platforms:
436 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
439 Intel 32-bit architecture (IA32), Linux-Libre kernel;
442 ARMv7-A architecture with hard float, Thumb-2 and NEON,
443 using the EABI hard-float application binary interface (ABI),
444 and Linux-Libre kernel.
447 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
450 little-endian 64-bit MIPS processors, specifically the Loongson series,
451 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
452 supported; in particular, the project's build farms no longer provide
453 substitutes for this architecture.
457 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
458 configuration and Guix takes care of instantiating the configuration in a
459 transactional, reproducible, and stateless fashion (@pxref{System
460 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
461 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
462 Manual}), the well-known GNU utilities and tool chain, as well as the
463 graphical environment or system services of your choice.
465 Guix System is available on all the above platforms except
466 @code{mips64el-linux}.
469 For information on porting to other architectures or kernels,
472 Building this distribution is a cooperative effort, and you are invited
473 to join! @xref{Contributing}, for information about how you can help.
476 @c *********************************************************************
478 @chapter Installation
480 @cindex installing Guix
483 We recommend the use of this
484 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
485 shell installer script} to install Guix on top of a running GNU/Linux system,
486 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
487 with the installation of the package manager, which can be done on top of a
488 running GNU/Linux system. If, instead, you want to install the complete GNU
489 operating system, @pxref{System Installation}.} The script automates the
490 download, installation, and initial configuration of Guix. It should be run
494 @cindex foreign distro
495 @cindex directories related to foreign distro
496 When installed on a foreign distro, GNU@tie{}Guix complements the available
497 tools without interference. Its data lives exclusively in two directories,
498 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
499 such as @file{/etc}, are left untouched.
501 Once installed, Guix can be updated by running @command{guix pull}
502 (@pxref{Invoking guix pull}).
504 If you prefer to perform the installation steps manually or want to tweak
505 them, you may find the following subsections useful. They describe the
506 software requirements of Guix, as well as how to install it manually and get
510 * Binary Installation:: Getting Guix running in no time!
511 * Requirements:: Software needed to build and run Guix.
512 * Running the Test Suite:: Testing Guix.
513 * Setting Up the Daemon:: Preparing the build daemon's environment.
514 * Invoking guix-daemon:: Running the build daemon.
515 * Application Setup:: Application-specific setup.
518 @node Binary Installation
519 @section Binary Installation
521 @cindex installing Guix from binaries
522 @cindex installer script
523 This section describes how to install Guix on an arbitrary system from a
524 self-contained tarball providing binaries for Guix and for all its
525 dependencies. This is often quicker than installing from source, which
526 is described in the next sections. The only requirement is to have
529 @c Note duplicated from the ``Installation'' node.
531 We recommend the use of this
532 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
533 shell installer script}. The script automates the download, installation, and
534 initial configuration steps described below. It should be run as the root
538 Installing goes along these lines:
542 @cindex downloading Guix binary
543 Download the binary tarball from
544 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
545 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
546 already running the kernel Linux, and so on.
548 @c The following is somewhat duplicated in ``System Installation''.
549 Make sure to download the associated @file{.sig} file and to verify the
550 authenticity of the tarball against it, along these lines:
553 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
554 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
557 If that command fails because you do not have the required public key,
558 then run this command to import it:
561 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
562 -qO - | gpg --import -
566 and rerun the @code{gpg --verify} command.
567 @c end authentication part
570 Now, you need to become the @code{root} user. Depending on your distribution,
571 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
575 # tar --warning=no-timestamp -xf \
576 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
577 # mv var/guix /var/ && mv gnu /
580 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
581 The latter contains a ready-to-use profile for @code{root} (see next
584 Do @emph{not} unpack the tarball on a working Guix system since that
585 would overwrite its own essential files.
587 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
588 not emit warnings about ``implausibly old time stamps'' (such
589 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
591 They stem from the fact that all the
592 files in the archive have their modification time set to zero (which
593 means January 1st, 1970.) This is done on purpose to make sure the
594 archive content is independent of its creation time, thus making it
598 Make the profile available under @file{~root/.config/guix/current}, which is
599 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
602 # mkdir -p ~root/.config/guix
603 # ln -sf /var/guix/profiles/per-user/root/current-guix \
604 ~root/.config/guix/current
607 Source @file{etc/profile} to augment @code{PATH} and other relevant
608 environment variables:
611 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
612 source $GUIX_PROFILE/etc/profile
616 Create the group and user accounts for build users as explained below
617 (@pxref{Build Environment Setup}).
620 Run the daemon, and set it to automatically start on boot.
622 If your host distro uses the systemd init system, this can be achieved
625 @c Versions of systemd that supported symlinked service files are not
626 @c yet widely deployed, so we should suggest that users copy the service
629 @c See this thread for more information:
630 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
633 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
635 # systemctl start guix-daemon && systemctl enable guix-daemon
638 If your host distro uses the Upstart init system:
641 # initctl reload-configuration
642 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
647 Otherwise, you can still start the daemon manually with:
650 # ~root/.config/guix/current/bin/guix-daemon \
651 --build-users-group=guixbuild
655 Make the @command{guix} command available to other users on the machine,
659 # mkdir -p /usr/local/bin
661 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
664 It is also a good idea to make the Info version of this manual available
668 # mkdir -p /usr/local/share/info
669 # cd /usr/local/share/info
670 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
674 That way, assuming @file{/usr/local/share/info} is in the search path,
675 running @command{info guix} will open this manual (@pxref{Other Info
676 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
680 @cindex substitutes, authorization thereof
681 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
682 (@pxref{Substitutes}), authorize them:
685 # guix archive --authorize < \
686 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
690 Each user may need to perform a few additional steps to make their Guix
691 environment ready for use, @pxref{Application Setup}.
694 Voilà, the installation is complete!
696 You can confirm that Guix is working by installing a sample package into
703 The binary installation tarball can be (re)produced and verified simply
704 by running the following command in the Guix source tree:
707 make guix-binary.@var{system}.tar.xz
711 ...@: which, in turn, runs:
714 guix pack -s @var{system} --localstatedir \
715 --profile-name=current-guix guix
718 @xref{Invoking guix pack}, for more info on this handy tool.
721 @section Requirements
723 This section lists requirements when building Guix from source. The
724 build procedure for Guix is the same as for other GNU software, and is
725 not covered here. Please see the files @file{README} and @file{INSTALL}
726 in the Guix source tree for additional details.
728 @cindex official website
729 GNU Guix is available for download from its website at
730 @url{https://www.gnu.org/software/guix/}.
732 GNU Guix depends on the following packages:
735 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
736 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
739 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
740 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
741 Guile,, gnutls-guile, GnuTLS-Guile});
743 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
746 @c FIXME: Specify a version number once a release has been made.
747 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
749 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
750 @item @url{https://zlib.net, zlib};
751 @item @url{https://www.gnu.org/software/make/, GNU Make}.
754 The following dependencies are optional:
758 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
759 Support for build offloading (@pxref{Daemon Offload Setup}) and
760 @command{guix copy} (@pxref{Invoking guix copy}) depends on
761 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
762 version 0.10.2 or later.
765 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
766 substitutes can be used and @command{guix publish} can compress substitutes
770 When @url{http://www.bzip.org, libbz2} is available,
771 @command{guix-daemon} can use it to compress build logs.
774 Unless @code{--disable-daemon} was passed to @command{configure}, the
775 following packages are also needed:
778 @item @url{https://gnupg.org/, GNU libgcrypt};
779 @item @url{https://sqlite.org, SQLite 3};
780 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
784 @cindex state directory
785 When configuring Guix on a system that already has a Guix installation,
786 be sure to specify the same state directory as the existing installation
787 using the @code{--localstatedir} option of the @command{configure}
788 script (@pxref{Directory Variables, @code{localstatedir},, standards,
789 GNU Coding Standards}). The @command{configure} script protects against
790 unintended misconfiguration of @var{localstatedir} so you do not
791 inadvertently corrupt your store (@pxref{The Store}).
793 @cindex Nix, compatibility
794 When a working installation of @url{https://nixos.org/nix/, the Nix package
795 manager} is available, you
796 can instead configure Guix with @code{--disable-daemon}. In that case,
797 Nix replaces the three dependencies above.
799 Guix is compatible with Nix, so it is possible to share the same store
800 between both. To do so, you must pass @command{configure} not only the
801 same @code{--with-store-dir} value, but also the same
802 @code{--localstatedir} value. The latter is essential because it
803 specifies where the database that stores metadata about the store is
804 located, among other things. The default values for Nix are
805 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
806 Note that @code{--disable-daemon} is not required if
807 your goal is to share the store with Nix.
809 @node Running the Test Suite
810 @section Running the Test Suite
813 After a successful @command{configure} and @code{make} run, it is a good
814 idea to run the test suite. It can help catch issues with the setup or
815 environment, or bugs in Guix itself---and really, reporting test
816 failures is a good way to help improve the software. To run the test
823 Test cases can run in parallel: you can use the @code{-j} option of
824 GNU@tie{}make to speed things up. The first run may take a few minutes
825 on a recent machine; subsequent runs will be faster because the store
826 that is created for test purposes will already have various things in
829 It is also possible to run a subset of the tests by defining the
830 @code{TESTS} makefile variable as in this example:
833 make check TESTS="tests/store.scm tests/cpio.scm"
836 By default, tests results are displayed at a file level. In order to
837 see the details of every individual test cases, it is possible to define
838 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
841 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
844 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
845 @file{test-suite.log} file. Please specify the Guix version being used
846 as well as version numbers of the dependencies (@pxref{Requirements}) in
849 Guix also comes with a whole-system test suite that tests complete
850 Guix System instances. It can only run on systems where
851 Guix is already installed, using:
858 or, again, by defining @code{TESTS} to select a subset of tests to run:
861 make check-system TESTS="basic mcron"
864 These system tests are defined in the @code{(gnu tests @dots{})}
865 modules. They work by running the operating systems under test with
866 lightweight instrumentation in a virtual machine (VM). They can be
867 computationally intensive or rather cheap, depending on whether
868 substitutes are available for their dependencies (@pxref{Substitutes}).
869 Some of them require a lot of storage space to hold VM images.
871 Again in case of test failures, please send @email{bug-guix@@gnu.org}
874 @node Setting Up the Daemon
875 @section Setting Up the Daemon
878 Operations such as building a package or running the garbage collector
879 are all performed by a specialized process, the @dfn{build daemon}, on
880 behalf of clients. Only the daemon may access the store and its
881 associated database. Thus, any operation that manipulates the store
882 goes through the daemon. For instance, command-line tools such as
883 @command{guix package} and @command{guix build} communicate with the
884 daemon (@i{via} remote procedure calls) to instruct it what to do.
886 The following sections explain how to prepare the build daemon's
887 environment. See also @ref{Substitutes}, for information on how to allow
888 the daemon to download pre-built binaries.
891 * Build Environment Setup:: Preparing the isolated build environment.
892 * Daemon Offload Setup:: Offloading builds to remote machines.
893 * SELinux Support:: Using an SELinux policy for the daemon.
896 @node Build Environment Setup
897 @subsection Build Environment Setup
899 @cindex build environment
900 In a standard multi-user setup, Guix and its daemon---the
901 @command{guix-daemon} program---are installed by the system
902 administrator; @file{/gnu/store} is owned by @code{root} and
903 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
904 Guix tools to build packages or otherwise access the store, and the
905 daemon will do it on their behalf, ensuring that the store is kept in a
906 consistent state, and allowing built packages to be shared among users.
909 When @command{guix-daemon} runs as @code{root}, you may not want package
910 build processes themselves to run as @code{root} too, for obvious
911 security reasons. To avoid that, a special pool of @dfn{build users}
912 should be created for use by build processes started by the daemon.
913 These build users need not have a shell and a home directory: they will
914 just be used when the daemon drops @code{root} privileges in build
915 processes. Having several such users allows the daemon to launch
916 distinct build processes under separate UIDs, which guarantees that they
917 do not interfere with each other---an essential feature since builds are
918 regarded as pure functions (@pxref{Introduction}).
920 On a GNU/Linux system, a build user pool may be created like this (using
921 Bash syntax and the @code{shadow} commands):
923 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
924 @c for why `-G' is needed.
926 # groupadd --system guixbuild
927 # for i in `seq -w 1 10`;
929 useradd -g guixbuild -G guixbuild \
930 -d /var/empty -s `which nologin` \
931 -c "Guix build user $i" --system \
937 The number of build users determines how many build jobs may run in
938 parallel, as specified by the @option{--max-jobs} option
939 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
940 @command{guix system vm} and related commands, you may need to add the
941 build users to the @code{kvm} group so they can access @file{/dev/kvm},
942 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
943 (@pxref{Invoking guix system}).
945 The @code{guix-daemon} program may then be run as @code{root} with the
946 following command@footnote{If your machine uses the systemd init system,
947 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
948 file in @file{/etc/systemd/system} will ensure that
949 @command{guix-daemon} is automatically started. Similarly, if your
950 machine uses the Upstart init system, drop the
951 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
952 file in @file{/etc/init}.}:
955 # guix-daemon --build-users-group=guixbuild
960 This way, the daemon starts build processes in a chroot, under one of
961 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
962 environment contains nothing but:
964 @c Keep this list in sync with libstore/build.cc! -----------------------
967 a minimal @code{/dev} directory, created mostly independently from the
968 host @code{/dev}@footnote{``Mostly'', because while the set of files
969 that appear in the chroot's @code{/dev} is fixed, most of these files
970 can only be created if the host has them.};
973 the @code{/proc} directory; it only shows the processes of the container
974 since a separate PID name space is used;
977 @file{/etc/passwd} with an entry for the current user and an entry for
981 @file{/etc/group} with an entry for the user's group;
984 @file{/etc/hosts} with an entry that maps @code{localhost} to
988 a writable @file{/tmp} directory.
991 You can influence the directory where the daemon stores build trees
992 @i{via} the @code{TMPDIR} environment variable. However, the build tree
993 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
994 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
995 This way, the value of @code{TMPDIR} does not leak inside build
996 environments, which avoids discrepancies in cases where build processes
997 capture the name of their build tree.
1000 The daemon also honors the @code{http_proxy} environment variable for
1001 HTTP downloads it performs, be it for fixed-output derivations
1002 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1004 If you are installing Guix as an unprivileged user, it is still possible
1005 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1006 However, build processes will not be isolated from one another, and not
1007 from the rest of the system. Thus, build processes may interfere with
1008 each other, and may access programs, libraries, and other files
1009 available on the system---making it much harder to view them as
1010 @emph{pure} functions.
1013 @node Daemon Offload Setup
1014 @subsection Using the Offload Facility
1018 When desired, the build daemon can @dfn{offload} derivation builds to
1019 other machines running Guix, using the @code{offload} @dfn{build
1020 hook}@footnote{This feature is available only when
1021 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1022 present.}. When that
1023 feature is enabled, a list of user-specified build machines is read from
1024 @file{/etc/guix/machines.scm}; every time a build is requested, for
1025 instance via @code{guix build}, the daemon attempts to offload it to one
1026 of the machines that satisfy the constraints of the derivation, in
1027 particular its system type---e.g., @file{x86_64-linux}. Missing
1028 prerequisites for the build are copied over SSH to the target machine,
1029 which then proceeds with the build; upon success the output(s) of the
1030 build are copied back to the initial machine.
1032 The @file{/etc/guix/machines.scm} file typically looks like this:
1035 (list (build-machine
1036 (name "eightysix.example.org")
1037 (system "x86_64-linux")
1038 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1040 (speed 2.)) ;incredibly fast!
1043 (name "meeps.example.org")
1044 (system "mips64el-linux")
1045 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1048 (string-append (getenv "HOME")
1049 "/.ssh/identity-for-guix"))))
1053 In the example above we specify a list of two build machines, one for
1054 the @code{x86_64} architecture and one for the @code{mips64el}
1057 In fact, this file is---not surprisingly!---a Scheme file that is
1058 evaluated when the @code{offload} hook is started. Its return value
1059 must be a list of @code{build-machine} objects. While this example
1060 shows a fixed list of build machines, one could imagine, say, using
1061 DNS-SD to return a list of potential build machines discovered in the
1062 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1063 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1066 @deftp {Data Type} build-machine
1067 This data type represents build machines to which the daemon may offload
1068 builds. The important fields are:
1073 The host name of the remote machine.
1076 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1079 The user account to use when connecting to the remote machine over SSH.
1080 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1081 allow non-interactive logins.
1084 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1085 This is used to authenticate the machine when we connect to it. It is a
1086 long string that looks like this:
1089 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1092 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1093 key can be found in a file such as
1094 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1096 If the machine is running the SSH daemon of GNU@tie{}lsh,
1097 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1098 similar file. It can be converted to the OpenSSH format using
1099 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1102 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1103 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1108 A number of optional fields may be specified:
1112 @item @code{port} (default: @code{22})
1113 Port number of SSH server on the machine.
1115 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1116 The SSH private key file to use when connecting to the machine, in
1117 OpenSSH format. This key must not be protected with a passphrase.
1119 Note that the default value is the private key @emph{of the root
1120 account}. Make sure it exists if you use the default.
1122 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1123 @itemx @code{compression-level} (default: @code{3})
1124 The SSH-level compression methods and compression level requested.
1126 Note that offloading relies on SSH compression to reduce bandwidth usage
1127 when transferring files to and from build machines.
1129 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1130 File name of the Unix-domain socket @command{guix-daemon} is listening
1133 @item @code{parallel-builds} (default: @code{1})
1134 The number of builds that may run in parallel on the machine.
1136 @item @code{speed} (default: @code{1.0})
1137 A ``relative speed factor''. The offload scheduler will tend to prefer
1138 machines with a higher speed factor.
1140 @item @code{features} (default: @code{'()})
1141 A list of strings denoting specific features supported by the machine.
1142 An example is @code{"kvm"} for machines that have the KVM Linux modules
1143 and corresponding hardware support. Derivations can request features by
1144 name, and they will be scheduled on matching build machines.
1149 The @command{guix} command must be in the search path on the build
1150 machines. You can check whether this is the case by running:
1153 ssh build-machine guix repl --version
1156 There is one last thing to do once @file{machines.scm} is in place. As
1157 explained above, when offloading, files are transferred back and forth
1158 between the machine stores. For this to work, you first need to
1159 generate a key pair on each machine to allow the daemon to export signed
1160 archives of files from the store (@pxref{Invoking guix archive}):
1163 # guix archive --generate-key
1167 Each build machine must authorize the key of the master machine so that
1168 it accepts store items it receives from the master:
1171 # guix archive --authorize < master-public-key.txt
1175 Likewise, the master machine must authorize the key of each build machine.
1177 All the fuss with keys is here to express pairwise mutual trust
1178 relations between the master and the build machines. Concretely, when
1179 the master receives files from a build machine (and @i{vice versa}), its
1180 build daemon can make sure they are genuine, have not been tampered
1181 with, and that they are signed by an authorized key.
1183 @cindex offload test
1184 To test whether your setup is operational, run this command on the
1191 This will attempt to connect to each of the build machines specified in
1192 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1193 available on each machine, attempt to export to the machine and import
1194 from it, and report any error in the process.
1196 If you want to test a different machine file, just specify it on the
1200 # guix offload test machines-qualif.scm
1203 Last, you can test the subset of the machines whose name matches a
1204 regular expression like this:
1207 # guix offload test machines.scm '\.gnu\.org$'
1210 @cindex offload status
1211 To display the current load of all build hosts, run this command on the
1215 # guix offload status
1219 @node SELinux Support
1220 @subsection SELinux Support
1222 @cindex SELinux, daemon policy
1223 @cindex mandatory access control, SELinux
1224 @cindex security, guix-daemon
1225 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1226 can be installed on a system where SELinux is enabled, in order to label
1227 Guix files and to specify the expected behavior of the daemon. Since
1228 Guix System does not provide an SELinux base policy, the daemon policy cannot
1229 be used on Guix System.
1231 @subsubsection Installing the SELinux policy
1232 @cindex SELinux, policy installation
1233 To install the policy run this command as root:
1236 semodule -i etc/guix-daemon.cil
1239 Then relabel the file system with @code{restorecon} or by a different
1240 mechanism provided by your system.
1242 Once the policy is installed, the file system has been relabeled, and
1243 the daemon has been restarted, it should be running in the
1244 @code{guix_daemon_t} context. You can confirm this with the following
1248 ps -Zax | grep guix-daemon
1251 Monitor the SELinux log files as you run a command like @code{guix build
1252 hello} to convince yourself that SELinux permits all necessary
1255 @subsubsection Limitations
1256 @cindex SELinux, limitations
1258 This policy is not perfect. Here is a list of limitations or quirks
1259 that should be considered when deploying the provided SELinux policy for
1264 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1265 operations involve contexts that have anything to do with
1266 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1267 but it would be preferrable to define socket rules for only this label.
1270 @code{guix gc} cannot access arbitrary links to profiles. By design,
1271 the file label of the destination of a symlink is independent of the
1272 file label of the link itself. Although all profiles under
1273 $localstatedir are labelled, the links to these profiles inherit the
1274 label of the directory they are in. For links in the user’s home
1275 directory this will be @code{user_home_t}. But for links from the root
1276 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1277 directory, etc, this won’t work. @code{guix gc} would be prevented from
1278 reading and following these links.
1281 The daemon’s feature to listen for TCP connections might no longer work.
1282 This might require extra rules, because SELinux treats network sockets
1283 differently from files.
1286 Currently all files with a name matching the regular expression
1287 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1288 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1289 that name in any profile would be permitted to run in the
1290 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1291 build a package that provides this executable and convince a user to
1292 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1293 At that point SELinux could not prevent it from accessing files that are
1294 allowed for processes in that domain.
1296 We could generate a much more restrictive policy at installation time,
1297 so that only the @emph{exact} file name of the currently installed
1298 @code{guix-daemon} executable would be labelled with
1299 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1300 The downside is that root would have to install or upgrade the policy at
1301 installation time whenever the Guix package that provides the
1302 effectively running @code{guix-daemon} executable is upgraded.
1305 @node Invoking guix-daemon
1306 @section Invoking @command{guix-daemon}
1308 The @command{guix-daemon} program implements all the functionality to
1309 access the store. This includes launching build processes, running the
1310 garbage collector, querying the availability of a build result, etc. It
1311 is normally run as @code{root} like this:
1314 # guix-daemon --build-users-group=guixbuild
1318 For details on how to set it up, @pxref{Setting Up the Daemon}.
1321 @cindex container, build environment
1322 @cindex build environment
1323 @cindex reproducible builds
1324 By default, @command{guix-daemon} launches build processes under
1325 different UIDs, taken from the build group specified with
1326 @code{--build-users-group}. In addition, each build process is run in a
1327 chroot environment that only contains the subset of the store that the
1328 build process depends on, as specified by its derivation
1329 (@pxref{Programming Interface, derivation}), plus a set of specific
1330 system directories. By default, the latter contains @file{/dev} and
1331 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1332 @dfn{container}: in addition to having its own file system tree, it has
1333 a separate mount name space, its own PID name space, network name space,
1334 etc. This helps achieve reproducible builds (@pxref{Features}).
1336 When the daemon performs a build on behalf of the user, it creates a
1337 build directory under @file{/tmp} or under the directory specified by
1338 its @code{TMPDIR} environment variable. This directory is shared with
1339 the container for the duration of the build, though within the container,
1340 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1342 The build directory is automatically deleted upon completion, unless the
1343 build failed and the client specified @option{--keep-failed}
1344 (@pxref{Invoking guix build, @option{--keep-failed}}).
1346 The daemon listens for connections and spawns one sub-process for each session
1347 started by a client (one of the @command{guix} sub-commands.) The
1348 @command{guix processes} command allows you to get an overview of the activity
1349 on your system by viewing each of the active sessions and clients.
1350 @xref{Invoking guix processes}, for more information.
1352 The following command-line options are supported:
1355 @item --build-users-group=@var{group}
1356 Take users from @var{group} to run build processes (@pxref{Setting Up
1357 the Daemon, build users}).
1359 @item --no-substitutes
1361 Do not use substitutes for build products. That is, always build things
1362 locally instead of allowing downloads of pre-built binaries
1363 (@pxref{Substitutes}).
1365 When the daemon runs with @code{--no-substitutes}, clients can still
1366 explicitly enable substitution @i{via} the @code{set-build-options}
1367 remote procedure call (@pxref{The Store}).
1369 @item --substitute-urls=@var{urls}
1370 @anchor{daemon-substitute-urls}
1371 Consider @var{urls} the default whitespace-separated list of substitute
1372 source URLs. When this option is omitted,
1373 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1375 This means that substitutes may be downloaded from @var{urls}, as long
1376 as they are signed by a trusted signature (@pxref{Substitutes}).
1379 @item --no-build-hook
1380 Do not use the @dfn{build hook}.
1382 The build hook is a helper program that the daemon can start and to
1383 which it submits build requests. This mechanism is used to offload
1384 builds to other machines (@pxref{Daemon Offload Setup}).
1386 @item --cache-failures
1387 Cache build failures. By default, only successful builds are cached.
1389 When this option is used, @command{guix gc --list-failures} can be used
1390 to query the set of store items marked as failed; @command{guix gc
1391 --clear-failures} removes store items from the set of cached failures.
1392 @xref{Invoking guix gc}.
1394 @item --cores=@var{n}
1396 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1399 The default value is @code{0}, but it may be overridden by clients, such
1400 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1403 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1404 in the build process, which can then use it to exploit internal
1405 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1407 @item --max-jobs=@var{n}
1409 Allow at most @var{n} build jobs in parallel. The default value is
1410 @code{1}. Setting it to @code{0} means that no builds will be performed
1411 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1412 Setup}), or simply fail.
1414 @item --max-silent-time=@var{seconds}
1415 When the build or substitution process remains silent for more than
1416 @var{seconds}, terminate it and report a build failure.
1418 The default value is @code{0}, which disables the timeout.
1420 The value specified here can be overridden by clients (@pxref{Common
1421 Build Options, @code{--max-silent-time}}).
1423 @item --timeout=@var{seconds}
1424 Likewise, when the build or substitution process lasts for more than
1425 @var{seconds}, terminate it and report a build failure.
1427 The default value is @code{0}, which disables the timeout.
1429 The value specified here can be overridden by clients (@pxref{Common
1430 Build Options, @code{--timeout}}).
1432 @item --rounds=@var{N}
1433 Build each derivation @var{n} times in a row, and raise an error if
1434 consecutive build results are not bit-for-bit identical. Note that this
1435 setting can be overridden by clients such as @command{guix build}
1436 (@pxref{Invoking guix build}).
1438 When used in conjunction with @option{--keep-failed}, the differing
1439 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1440 This makes it easy to look for differences between the two results.
1443 Produce debugging output.
1445 This is useful to debug daemon start-up issues, but then it may be
1446 overridden by clients, for example the @code{--verbosity} option of
1447 @command{guix build} (@pxref{Invoking guix build}).
1449 @item --chroot-directory=@var{dir}
1450 Add @var{dir} to the build chroot.
1452 Doing this may change the result of build processes---for instance if
1453 they use optional dependencies found in @var{dir} when it is available,
1454 and not otherwise. For that reason, it is not recommended to do so.
1455 Instead, make sure that each derivation declares all the inputs that it
1458 @item --disable-chroot
1459 Disable chroot builds.
1461 Using this option is not recommended since, again, it would allow build
1462 processes to gain access to undeclared dependencies. It is necessary,
1463 though, when @command{guix-daemon} is running under an unprivileged user
1466 @item --log-compression=@var{type}
1467 Compress build logs according to @var{type}, one of @code{gzip},
1468 @code{bzip2}, or @code{none}.
1470 Unless @code{--lose-logs} is used, all the build logs are kept in the
1471 @var{localstatedir}. To save space, the daemon automatically compresses
1472 them with bzip2 by default.
1474 @item --disable-deduplication
1475 @cindex deduplication
1476 Disable automatic file ``deduplication'' in the store.
1478 By default, files added to the store are automatically ``deduplicated'':
1479 if a newly added file is identical to another one found in the store,
1480 the daemon makes the new file a hard link to the other file. This can
1481 noticeably reduce disk usage, at the expense of slightly increased
1482 input/output load at the end of a build process. This option disables
1485 @item --gc-keep-outputs[=yes|no]
1486 Tell whether the garbage collector (GC) must keep outputs of live
1490 @cindex garbage collector roots
1491 When set to ``yes'', the GC will keep the outputs of any live derivation
1492 available in the store---the @code{.drv} files. The default is ``no'',
1493 meaning that derivation outputs are kept only if they are reachable from a GC
1494 root. @xref{Invoking guix gc}, for more on GC roots.
1496 @item --gc-keep-derivations[=yes|no]
1497 Tell whether the garbage collector (GC) must keep derivations
1498 corresponding to live outputs.
1500 When set to ``yes'', as is the case by default, the GC keeps
1501 derivations---i.e., @code{.drv} files---as long as at least one of their
1502 outputs is live. This allows users to keep track of the origins of
1503 items in their store. Setting it to ``no'' saves a bit of disk space.
1505 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1506 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1507 ``yes'' causes liveness to flow from derivations to outputs. When both are
1508 set to ``yes'', the effect is to keep all the build prerequisites (the
1509 sources, compiler, libraries, and other build-time tools) of live objects in
1510 the store, regardless of whether these prerequisites are reachable from a GC
1511 root. This is convenient for developers since it saves rebuilds or downloads.
1513 @item --impersonate-linux-2.6
1514 On Linux-based systems, impersonate Linux 2.6. This means that the
1515 kernel's @code{uname} system call will report 2.6 as the release number.
1517 This might be helpful to build programs that (usually wrongfully) depend
1518 on the kernel version number.
1521 Do not keep build logs. By default they are kept under
1522 @code{@var{localstatedir}/guix/log}.
1524 @item --system=@var{system}
1525 Assume @var{system} as the current system type. By default it is the
1526 architecture/kernel pair found at configure time, such as
1527 @code{x86_64-linux}.
1529 @item --listen=@var{endpoint}
1530 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1531 as the file name of a Unix-domain socket if it starts with
1532 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1533 host name or host name and port to listen to. Here are a few examples:
1536 @item --listen=/gnu/var/daemon
1537 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1538 creating it if needed.
1540 @item --listen=localhost
1541 @cindex daemon, remote access
1542 @cindex remote access to the daemon
1543 @cindex daemon, cluster setup
1544 @cindex clusters, daemon setup
1545 Listen for TCP connections on the network interface corresponding to
1546 @code{localhost}, on port 44146.
1548 @item --listen=128.0.0.42:1234
1549 Listen for TCP connections on the network interface corresponding to
1550 @code{128.0.0.42}, on port 1234.
1553 This option can be repeated multiple times, in which case
1554 @command{guix-daemon} accepts connections on all the specified
1555 endpoints. Users can tell client commands what endpoint to connect to
1556 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1557 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1560 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1561 @code{--listen=@var{host}} is suitable on local networks, such as
1562 clusters, where only trusted nodes may connect to the build daemon. In
1563 other cases where remote access to the daemon is needed, we recommend
1564 using Unix-domain sockets along with SSH.
1567 When @code{--listen} is omitted, @command{guix-daemon} listens for
1568 connections on the Unix-domain socket located at
1569 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1573 @node Application Setup
1574 @section Application Setup
1576 @cindex foreign distro
1577 When using Guix on top of GNU/Linux distribution other than Guix System---a
1578 so-called @dfn{foreign distro}---a few additional steps are needed to
1579 get everything in place. Here are some of them.
1583 @anchor{locales-and-locpath}
1584 @cindex locales, when not on Guix System
1586 @vindex GUIX_LOCPATH
1587 Packages installed @i{via} Guix will not use the locale data of the
1588 host system. Instead, you must first install one of the locale packages
1589 available with Guix and then define the @code{GUIX_LOCPATH} environment
1593 $ guix install glibc-locales
1594 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1597 Note that the @code{glibc-locales} package contains data for all the
1598 locales supported by the GNU@tie{}libc and weighs in at around
1599 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1600 limited to a few UTF-8 locales.
1602 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1603 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1604 Manual}). There are two important differences though:
1608 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1609 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1610 to make sure the programs of the foreign distro will not end up loading
1611 incompatible locale data.
1614 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1615 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1616 should your Guix profile contain a mixture of programs linked against
1617 different libc version, each libc version will only try to load locale
1618 data in the right format.
1621 This is important because the locale data format used by different libc
1622 versions may be incompatible.
1624 @subsection Name Service Switch
1626 @cindex name service switch, glibc
1627 @cindex NSS (name service switch), glibc
1628 @cindex nscd (name service caching daemon)
1629 @cindex name service caching daemon (nscd)
1630 When using Guix on a foreign distro, we @emph{strongly recommend} that
1631 the system run the GNU C library's @dfn{name service cache daemon},
1632 @command{nscd}, which should be listening on the
1633 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1634 installed with Guix may fail to look up host names or user accounts, or
1635 may even crash. The next paragraphs explain why.
1637 @cindex @file{nsswitch.conf}
1638 The GNU C library implements a @dfn{name service switch} (NSS), which is
1639 an extensible mechanism for ``name lookups'' in general: host name
1640 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1641 The GNU C Library Reference Manual}).
1643 @cindex Network information service (NIS)
1644 @cindex NIS (Network information service)
1645 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1646 lookup implementations: for example, the @code{nss-mdns} plugin allow
1647 resolution of @code{.local} host names, the @code{nis} plugin allows
1648 user account lookup using the Network information service (NIS), and so
1649 on. These extra ``lookup services'' are configured system-wide in
1650 @file{/etc/nsswitch.conf}, and all the programs running on the system
1651 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1654 When they perform a name lookup---for instance by calling the
1655 @code{getaddrinfo} function in C---applications first try to connect to
1656 the nscd; on success, nscd performs name lookups on their behalf. If
1657 the nscd is not running, then they perform the name lookup by
1658 themselves, by loading the name lookup services into their own address
1659 space and running it. These name lookup services---the
1660 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1661 the host system's C library, rather than from the C library the
1662 application is linked against (the C library coming from Guix).
1664 And this is where the problem is: if your application is linked against
1665 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1666 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1667 likely crash or have its name lookups fail unexpectedly.
1669 Running @command{nscd} on the system, among other advantages, eliminates
1670 this binary incompatibility problem because those @code{libnss_*.so}
1671 files are loaded in the @command{nscd} process, not in applications
1674 @subsection X11 Fonts
1677 The majority of graphical applications use Fontconfig to locate and
1678 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1679 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1680 by default. Thus, to allow graphical applications installed with Guix
1681 to display fonts, you have to install fonts with Guix as well.
1682 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1683 @code{font-gnu-freefont-ttf}.
1685 To display text written in Chinese languages, Japanese, or Korean in
1686 graphical applications, consider installing
1687 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1688 has multiple outputs, one per language family (@pxref{Packages with
1689 Multiple Outputs}). For instance, the following command installs fonts
1690 for Chinese languages:
1693 guix install font-adobe-source-han-sans:cn
1696 @cindex @code{xterm}
1697 Older programs such as @command{xterm} do not use Fontconfig and instead
1698 rely on server-side font rendering. Such programs require to specify a
1699 full name of a font using XLFD (X Logical Font Description), like this:
1702 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1705 To be able to use such full names for the TrueType fonts installed in
1706 your Guix profile, you need to extend the font path of the X server:
1708 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1709 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1711 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1714 @cindex @code{xlsfonts}
1715 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1716 to make sure your TrueType fonts are listed there.
1718 @cindex @code{fc-cache}
1720 After installing fonts you may have to refresh the font cache to use
1721 them in applications. The same applies when applications installed via
1722 Guix do not seem to find fonts. To force rebuilding of the font cache
1723 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1724 @code{fontconfig} package.
1726 @subsection X.509 Certificates
1728 @cindex @code{nss-certs}
1729 The @code{nss-certs} package provides X.509 certificates, which allow
1730 programs to authenticate Web servers accessed over HTTPS.
1732 When using Guix on a foreign distro, you can install this package and
1733 define the relevant environment variables so that packages know where to
1734 look for certificates. @xref{X.509 Certificates}, for detailed
1737 @subsection Emacs Packages
1739 @cindex @code{emacs}
1740 When you install Emacs packages with Guix, the elisp files may be placed
1741 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1743 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1744 directory exists because potentially there may exist thousands of Emacs
1745 packages and storing all their files in a single directory may not be
1746 reliable (because of name conflicts). So we think using a separate
1747 directory for each package is a good idea. It is very similar to how
1748 the Emacs package system organizes the file structure (@pxref{Package
1749 Files,,, emacs, The GNU Emacs Manual}).
1751 By default, Emacs (installed with Guix) ``knows'' where these packages
1752 are placed, so you do not need to perform any configuration. If, for
1753 some reason, you want to avoid auto-loading Emacs packages installed
1754 with Guix, you can do so by running Emacs with @code{--no-site-file}
1755 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1757 @subsection The GCC toolchain
1762 Guix offers individual compiler packages such as @code{gcc} but if you
1763 are in need of a complete toolchain for compiling and linking source
1764 code what you really want is the @code{gcc-toolchain} package. This
1765 package provides a complete GCC toolchain for C/C++ development,
1766 including GCC itself, the GNU C Library (headers and binaries, plus
1767 debugging symbols in the @code{debug} output), Binutils, and a linker
1770 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1771 passed to the linker, add corresponding @code{-rpath} arguments, and
1772 invoke the actual linker with this new set of arguments. You can instruct the
1773 wrapper to refuse to link against libraries not in the store by setting the
1774 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1778 @c *********************************************************************
1779 @node System Installation
1780 @chapter System Installation
1782 @cindex installing Guix System
1783 @cindex Guix System, installation
1784 This section explains how to install Guix System
1785 on a machine. Guix, as a package manager, can
1786 also be installed on top of a running GNU/Linux system,
1787 @pxref{Installation}.
1791 @c This paragraph is for people reading this from tty2 of the
1792 @c installation image.
1793 You are reading this documentation with an Info reader. For details on
1794 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1795 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1796 Info}. Hit @kbd{l} afterwards to come back here.
1798 Alternately, run @command{info info} in another tty to keep the manual
1804 * Limitations:: What you can expect.
1805 * Hardware Considerations:: Supported hardware.
1806 * USB Stick and DVD Installation:: Preparing the installation medium.
1807 * Preparing for Installation:: Networking, partitioning, etc.
1808 * Guided Graphical Installation:: Easy graphical installation.
1809 * Manual Installation:: Manual installation for wizards.
1810 * After System Installation:: When installation succeeded.
1811 * Installing Guix in a VM:: Guix System playground.
1812 * Building the Installation Image:: How this comes to be.
1816 @section Limitations
1818 We consider Guix System to be ready for a wide range of ``desktop'' and server
1819 use cases. The reliability guarantees it provides---transactional upgrades
1820 and rollbacks, reproducibility---make it a solid foundation.
1822 Nevertheless, before you proceed with the installation, be aware of the
1823 following noteworthy limitations applicable to version @value{VERSION}:
1827 Support for the Logical Volume Manager (LVM) is missing.
1830 More and more system services are provided (@pxref{Services}), but some
1834 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1835 as well as a number of X11 window managers. However, KDE is currently
1839 More than a disclaimer, this is an invitation to report issues (and success
1840 stories!), and to join us in improving it. @xref{Contributing}, for more
1844 @node Hardware Considerations
1845 @section Hardware Considerations
1847 @cindex hardware support on Guix System
1848 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1849 builds around the kernel Linux-libre, which means that only hardware for
1850 which free software drivers and firmware exist is supported. Nowadays,
1851 a wide range of off-the-shelf hardware is supported on
1852 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1853 Ethernet controllers. Unfortunately, there are still areas where
1854 hardware vendors deny users control over their own computing, and such
1855 hardware is not supported on Guix System.
1857 @cindex WiFi, hardware support
1858 One of the main areas where free drivers or firmware are lacking is WiFi
1859 devices. WiFi devices known to work include those using Atheros chips
1860 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1861 driver, and those using Broadcom/AirForce chips (BCM43xx with
1862 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1863 Linux-libre driver. Free firmware exists for both and is available
1864 out-of-the-box on Guix System, as part of @code{%base-firmware}
1865 (@pxref{operating-system Reference, @code{firmware}}).
1867 @cindex RYF, Respects Your Freedom
1868 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1869 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1870 certification program for hardware products that respect your freedom
1871 and your privacy and ensure that you have control over your device. We
1872 encourage you to check the list of RYF-certified devices.
1874 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1875 web site. It contains a catalog of hardware devices with information
1876 about their support in GNU/Linux.
1879 @node USB Stick and DVD Installation
1880 @section USB Stick and DVD Installation
1882 An ISO-9660 installation image that can be written to a USB stick or
1883 burnt to a DVD can be downloaded from
1884 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1885 where @var{system} is one of:
1889 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1892 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1895 @c start duplication of authentication part from ``Binary Installation''
1896 Make sure to download the associated @file{.sig} file and to verify the
1897 authenticity of the image against it, along these lines:
1900 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1901 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1904 If that command fails because you do not have the required public key,
1905 then run this command to import it:
1908 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1909 -qO - | gpg --import -
1913 and rerun the @code{gpg --verify} command.
1916 This image contains the tools necessary for an installation.
1917 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1919 @unnumberedsubsec Copying to a USB Stick
1921 To copy the image to a USB stick, follow these steps:
1925 Decompress the image using the @command{xz} command:
1928 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1932 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1933 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1934 copy the image with:
1937 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1941 Access to @file{/dev/sdX} usually requires root privileges.
1944 @unnumberedsubsec Burning on a DVD
1946 To copy the image to a DVD, follow these steps:
1950 Decompress the image using the @command{xz} command:
1953 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1957 Insert a blank DVD into your machine, and determine
1958 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1959 copy the image with:
1962 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1965 Access to @file{/dev/srX} usually requires root privileges.
1968 @unnumberedsubsec Booting
1970 Once this is done, you should be able to reboot the system and boot from
1971 the USB stick or DVD. The latter usually requires you to get in the
1972 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1974 @xref{Installing Guix in a VM}, if, instead, you would like to install
1975 Guix System in a virtual machine (VM).
1978 @node Preparing for Installation
1979 @section Preparing for Installation
1981 Once you have booted, you can use the guided graphical installer, which makes
1982 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1983 if you are already familiar with GNU/Linux and if you want more control than
1984 what the graphical installer provides, you can choose the ``manual''
1985 installation process (@pxref{Manual Installation}).
1987 The graphical installer is available on TTY1. You can obtain root shells on
1988 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1989 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1990 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1991 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1992 which allows you to select text with the left mouse button and to paste it
1993 with the middle button.
1996 Installation requires access to the Internet so that any missing
1997 dependencies of your system configuration can be downloaded. See the
1998 ``Networking'' section below.
2001 @node Guided Graphical Installation
2002 @section Guided Graphical Installation
2004 The graphical installer is a text-based user interface. It will guide you,
2005 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2007 The first dialog boxes allow you to set up the system as you use it during the
2008 installation: you can choose the language, keyboard layout, and set up
2009 networking, which will be used during the installation. The image below shows
2010 the networking dialog.
2012 @image{images/installer-network,5in,, networking setup with the graphical installer}
2014 Later steps allow you to partition your hard disk, as shown in the image
2015 below, to choose whether or not to use encrypted file systems, to enter the
2016 host name and root password, and to create an additional account, among other
2019 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2021 Note that, at any time, the installer allows you to exit the current
2022 installation step and resume at a previous step, as show in the image below.
2024 @image{images/installer-resume,5in,, resuming the installation process}
2026 Once you're done, the installer produces an operating system configuration and
2027 displays it (@pxref{Using the Configuration System}). At that point you can
2028 hit ``OK'' and installation will proceed. On success, you can reboot into the
2029 new system and enjoy. @xref{After System Installation}, for what's next!
2032 @node Manual Installation
2033 @section Manual Installation
2035 This section describes how you would ``manually'' install GNU@tie{}Guix System
2036 on your machine. This option requires familiarity with GNU/Linux, with the
2037 shell, and with common administration tools. If you think this is not for
2038 you, consider using the guided graphical installer (@pxref{Guided Graphical
2041 The installation system provides root shells on TTYs 3 to 6; press
2042 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2043 many common tools needed to install the system. But it is also a full-blown
2044 Guix System, which means that you can install additional packages, should you
2045 need it, using @command{guix package} (@pxref{Invoking guix package}).
2048 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2049 * Proceeding with the Installation:: Installing.
2052 @node Keyboard Layout and Networking and Partitioning
2053 @subsection Keyboard Layout, Networking, and Partitioning
2055 Before you can install the system, you may want to adjust the keyboard layout,
2056 set up networking, and partition your target hard disk. This section will
2057 guide you through this.
2059 @subsubsection Keyboard Layout
2061 @cindex keyboard layout
2062 The installation image uses the US qwerty keyboard layout. If you want
2063 to change it, you can use the @command{loadkeys} command. For example,
2064 the following command selects the Dvorak keyboard layout:
2070 See the files under @file{/run/current-system/profile/share/keymaps} for
2071 a list of available keyboard layouts. Run @command{man loadkeys} for
2074 @subsubsection Networking
2076 Run the following command to see what your network interfaces are called:
2083 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2089 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2090 Wired interfaces have a name starting with @samp{e}; for example, the
2091 interface corresponding to the first on-board Ethernet controller is
2092 called @samp{eno1}. Wireless interfaces have a name starting with
2093 @samp{w}, like @samp{w1p2s0}.
2096 @item Wired connection
2097 To configure a wired network run the following command, substituting
2098 @var{interface} with the name of the wired interface you want to use.
2101 ifconfig @var{interface} up
2104 @item Wireless connection
2107 To configure wireless networking, you can create a configuration file
2108 for the @command{wpa_supplicant} configuration tool (its location is not
2109 important) using one of the available text editors such as
2113 nano wpa_supplicant.conf
2116 As an example, the following stanza can go to this file and will work
2117 for many wireless networks, provided you give the actual SSID and
2118 passphrase for the network you are connecting to:
2122 ssid="@var{my-ssid}"
2124 psk="the network's secret passphrase"
2128 Start the wireless service and run it in the background with the
2129 following command (substitute @var{interface} with the name of the
2130 network interface you want to use):
2133 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2136 Run @command{man wpa_supplicant} for more information.
2140 At this point, you need to acquire an IP address. On a network where IP
2141 addresses are automatically assigned @i{via} DHCP, you can run:
2144 dhclient -v @var{interface}
2147 Try to ping a server to see if networking is up and running:
2153 Setting up network access is almost always a requirement because the
2154 image does not contain all the software and tools that may be needed.
2156 @cindex installing over SSH
2157 If you want to, you can continue the installation remotely by starting
2161 herd start ssh-daemon
2164 Make sure to either set a password with @command{passwd}, or configure
2165 OpenSSH public key authentication before logging in.
2167 @subsubsection Disk Partitioning
2169 Unless this has already been done, the next step is to partition, and
2170 then format the target partition(s).
2172 The installation image includes several partitioning tools, including
2173 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2174 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2175 the partition layout you want:
2181 If your disk uses the GUID Partition Table (GPT) format and you plan to
2182 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2183 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2186 @cindex EFI, installation
2187 @cindex UEFI, installation
2188 @cindex ESP, EFI system partition
2189 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2190 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2191 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2194 parted /dev/sda set 1 esp on
2198 @vindex grub-bootloader
2199 @vindex grub-efi-bootloader
2200 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2201 @file{/sys/firmware/efi} exists in the installation image, then you should
2202 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2203 Otherwise you should use the BIOS-based GRUB, known as
2204 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2208 Once you are done partitioning the target hard disk drive, you have to
2209 create a file system on the relevant partition(s)@footnote{Currently
2210 Guix System only supports ext4 and btrfs file systems. In particular, code
2211 that reads file system UUIDs and labels only works for these file system
2212 types.}. For the ESP, if you have one and assuming it is
2213 @file{/dev/sda1}, run:
2216 mkfs.fat -F32 /dev/sda1
2219 Preferably, assign file systems a label so that you can easily and
2220 reliably refer to them in @code{file-system} declarations (@pxref{File
2221 Systems}). This is typically done using the @code{-L} option of
2222 @command{mkfs.ext4} and related commands. So, assuming the target root
2223 partition lives at @file{/dev/sda2}, a file system with the label
2224 @code{my-root} can be created with:
2227 mkfs.ext4 -L my-root /dev/sda2
2230 @cindex encrypted disk
2231 If you are instead planning to encrypt the root partition, you can use
2232 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2233 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2234 @code{man cryptsetup}} for more information.) Assuming you want to
2235 store the root partition on @file{/dev/sda2}, the command sequence would
2236 be along these lines:
2239 cryptsetup luksFormat /dev/sda2
2240 cryptsetup open --type luks /dev/sda2 my-partition
2241 mkfs.ext4 -L my-root /dev/mapper/my-partition
2244 Once that is done, mount the target file system under @file{/mnt}
2245 with a command like (again, assuming @code{my-root} is the label of the
2249 mount LABEL=my-root /mnt
2252 Also mount any other file systems you would like to use on the target
2253 system relative to this path. If you have opted for @file{/boot/efi} as an
2254 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2255 found by @code{guix system init} afterwards.
2257 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2258 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2259 sure to initialize them with @command{mkswap}. Assuming you have one
2260 swap partition on @file{/dev/sda3}, you would run:
2267 Alternatively, you may use a swap file. For example, assuming that in
2268 the new system you want to use the file @file{/swapfile} as a swap file,
2269 you would run@footnote{This example will work for many types of file
2270 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2271 btrfs), the required steps may be different. For details, see the
2272 manual pages for @command{mkswap} and @command{swapon}.}:
2275 # This is 10 GiB of swap space. Adjust "count" to change the size.
2276 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2277 # For security, make the file readable and writable only by root.
2278 chmod 600 /mnt/swapfile
2279 mkswap /mnt/swapfile
2280 swapon /mnt/swapfile
2283 Note that if you have encrypted the root partition and created a swap
2284 file in its file system as described above, then the encryption also
2285 protects the swap file, just like any other file in that file system.
2287 @node Proceeding with the Installation
2288 @subsection Proceeding with the Installation
2290 With the target partitions ready and the target root mounted on
2291 @file{/mnt}, we're ready to go. First, run:
2294 herd start cow-store /mnt
2297 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2298 during the installation phase are written to the target disk on @file{/mnt}
2299 rather than kept in memory. This is necessary because the first phase of
2300 the @command{guix system init} command (see below) entails downloads or
2301 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2303 Next, you have to edit a file and
2304 provide the declaration of the operating system to be installed. To
2305 that end, the installation system comes with three text editors. We
2306 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2307 supports syntax highlighting and parentheses matching; other editors
2308 include GNU Zile (an Emacs clone), and
2309 nvi (a clone of the original BSD @command{vi} editor).
2310 We strongly recommend storing that file on the target root file system, say,
2311 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2312 configuration file once you have rebooted into the newly-installed system.
2314 @xref{Using the Configuration System}, for an overview of the
2315 configuration file. The example configurations discussed in that
2316 section are available under @file{/etc/configuration} in the
2317 installation image. Thus, to get started with a system configuration
2318 providing a graphical display server (a ``desktop'' system), you can run
2319 something along these lines:
2323 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2324 # nano /mnt/etc/config.scm
2327 You should pay attention to what your configuration file contains, and
2332 Make sure the @code{bootloader-configuration} form refers to the target
2333 you want to install GRUB on. It should mention @code{grub-bootloader} if
2334 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2335 for newer UEFI systems. For legacy systems, the @code{target} field
2336 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2337 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2338 currently mounted and a @code{file-system} entry is specified in your
2342 Be sure that your file system labels match the value of their respective
2343 @code{device} fields in your @code{file-system} configuration, assuming
2344 your @code{file-system} configuration uses the @code{file-system-label}
2345 procedure in its @code{device} field.
2348 If there are encrypted or RAID partitions, make sure to add a
2349 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2352 Once you are done preparing the configuration file, the new system must
2353 be initialized (remember that the target root file system is mounted
2357 guix system init /mnt/etc/config.scm /mnt
2361 This copies all the necessary files and installs GRUB on
2362 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2363 more information, @pxref{Invoking guix system}. This command may trigger
2364 downloads or builds of missing packages, which can take some time.
2366 Once that command has completed---and hopefully succeeded!---you can run
2367 @command{reboot} and boot into the new system. The @code{root} password
2368 in the new system is initially empty; other users' passwords need to be
2369 initialized by running the @command{passwd} command as @code{root},
2370 unless your configuration specifies otherwise
2371 (@pxref{user-account-password, user account passwords}).
2372 @xref{After System Installation}, for what's next!
2375 @node After System Installation
2376 @section After System Installation
2378 Success, you've now booted into Guix System! From then on, you can update the
2379 system whenever you want by running, say:
2383 sudo guix system reconfigure /etc/config.scm
2387 This builds a new system generation with the latest packages and services
2388 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2389 your system includes the latest security updates (@pxref{Security Updates}).
2391 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2393 @cindex sudo vs. @command{guix pull}
2394 Note that @command{sudo guix} runs your user's @command{guix} command and
2395 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2396 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2399 Join us on @code{#guix} on the Freenode IRC network or on
2400 @email{guix-devel@@gnu.org} to share your experience!
2403 @node Installing Guix in a VM
2404 @section Installing Guix in a Virtual Machine
2406 @cindex virtual machine, Guix System installation
2407 @cindex virtual private server (VPS)
2408 @cindex VPS (virtual private server)
2409 If you'd like to install Guix System in a virtual machine (VM) or on a
2410 virtual private server (VPS) rather than on your beloved machine, this
2413 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2414 disk image, follow these steps:
2418 First, retrieve and decompress the Guix system installation image as
2419 described previously (@pxref{USB Stick and DVD Installation}).
2422 Create a disk image that will hold the installed system. To make a
2423 qcow2-formatted disk image, use the @command{qemu-img} command:
2426 qemu-img create -f qcow2 guixsd.img 50G
2429 The resulting file will be much smaller than 50 GB (typically less than
2430 1 MB), but it will grow as the virtualized storage device is filled up.
2433 Boot the USB installation image in an VM:
2436 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2437 -net user -net nic,model=virtio -boot menu=on \
2438 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2439 -drive file=guixsd.img
2442 The ordering of the drives matters. @code{-enable-kvm} is optional, but
2443 significantly improves performance, @pxref{Running Guix in a VM}.
2445 In the VM console, quickly press the @kbd{F12} key to enter the boot
2446 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2450 You're now root in the VM, proceed with the installation process.
2451 @xref{Preparing for Installation}, and follow the instructions.
2454 Once installation is complete, you can boot the system that's on your
2455 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2458 @node Building the Installation Image
2459 @section Building the Installation Image
2461 @cindex installation image
2462 The installation image described above was built using the @command{guix
2463 system} command, specifically:
2466 guix system disk-image --file-system-type=iso9660 \
2467 gnu/system/install.scm
2470 Have a look at @file{gnu/system/install.scm} in the source tree,
2471 and see also @ref{Invoking guix system} for more information
2472 about the installation image.
2474 @section Building the Installation Image for ARM Boards
2476 Many ARM boards require a specific variant of the
2477 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2479 If you build a disk image and the bootloader is not available otherwise
2480 (on another boot drive etc), it's advisable to build an image that
2481 includes the bootloader, specifically:
2484 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2487 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2488 board, a list of possible boards will be printed.
2490 @c *********************************************************************
2491 @node Package Management
2492 @chapter Package Management
2495 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2496 remove software packages, without having to know about their build
2497 procedures or dependencies. Guix also goes beyond this obvious set of
2500 This chapter describes the main features of Guix, as well as the
2501 package management tools it provides. Along with the command-line
2502 interface described below (@pxref{Invoking guix package, @code{guix
2503 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2504 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2505 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2509 guix install emacs-guix
2513 * Features:: How Guix will make your life brighter.
2514 * Invoking guix package:: Package installation, removal, etc.
2515 * Substitutes:: Downloading pre-built binaries.
2516 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2517 * Invoking guix gc:: Running the garbage collector.
2518 * Invoking guix pull:: Fetching the latest Guix and distribution.
2519 * Channels:: Customizing the package collection.
2520 * Inferiors:: Interacting with another revision of Guix.
2521 * Invoking guix describe:: Display information about your Guix revision.
2522 * Invoking guix archive:: Exporting and importing store files.
2528 When using Guix, each package ends up in the @dfn{package store}, in its
2529 own directory---something that resembles
2530 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2532 Instead of referring to these directories, users have their own
2533 @dfn{profile}, which points to the packages that they actually want to
2534 use. These profiles are stored within each user's home directory, at
2535 @code{$HOME/.guix-profile}.
2537 For example, @code{alice} installs GCC 4.7.2. As a result,
2538 @file{/home/alice/.guix-profile/bin/gcc} points to
2539 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2540 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2541 simply continues to point to
2542 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2543 coexist on the same system without any interference.
2545 The @command{guix package} command is the central tool to manage
2546 packages (@pxref{Invoking guix package}). It operates on the per-user
2547 profiles, and can be used @emph{with normal user privileges}.
2549 @cindex transactions
2550 The command provides the obvious install, remove, and upgrade
2551 operations. Each invocation is actually a @emph{transaction}: either
2552 the specified operation succeeds, or nothing happens. Thus, if the
2553 @command{guix package} process is terminated during the transaction,
2554 or if a power outage occurs during the transaction, then the user's
2555 profile remains in its previous state, and remains usable.
2557 In addition, any package transaction may be @emph{rolled back}. So, if,
2558 for example, an upgrade installs a new version of a package that turns
2559 out to have a serious bug, users may roll back to the previous instance
2560 of their profile, which was known to work well. Similarly, the global
2561 system configuration on Guix is subject to
2562 transactional upgrades and roll-back
2563 (@pxref{Using the Configuration System}).
2565 All packages in the package store may be @emph{garbage-collected}.
2566 Guix can determine which packages are still referenced by user
2567 profiles, and remove those that are provably no longer referenced
2568 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2569 generations of their profile so that the packages they refer to can be
2572 @cindex reproducibility
2573 @cindex reproducible builds
2574 Guix takes a @dfn{purely functional} approach to package
2575 management, as described in the introduction (@pxref{Introduction}).
2576 Each @file{/gnu/store} package directory name contains a hash of all the
2577 inputs that were used to build that package---compiler, libraries, build
2578 scripts, etc. This direct correspondence allows users to make sure a
2579 given package installation matches the current state of their
2580 distribution. It also helps maximize @dfn{build reproducibility}:
2581 thanks to the isolated build environments that are used, a given build
2582 is likely to yield bit-identical files when performed on different
2583 machines (@pxref{Invoking guix-daemon, container}).
2586 This foundation allows Guix to support @dfn{transparent binary/source
2587 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2588 available from an external source---a @dfn{substitute}, Guix just
2589 downloads it and unpacks it;
2590 otherwise, it builds the package from source, locally
2591 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2592 reproducible, users do not have to trust servers that provide
2593 substitutes: they can force a local build and @emph{challenge} providers
2594 (@pxref{Invoking guix challenge}).
2596 Control over the build environment is a feature that is also useful for
2597 developers. The @command{guix environment} command allows developers of
2598 a package to quickly set up the right development environment for their
2599 package, without having to manually install the dependencies of the
2600 package into their profile (@pxref{Invoking guix environment}).
2602 @cindex replication, of software environments
2603 @cindex provenance tracking, of software artifacts
2604 All of Guix and its package definitions is version-controlled, and
2605 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2606 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2607 Guix instance on a different machine or at a later point in time, which in
2608 turn allows you to @emph{replicate complete software environments}, while
2609 retaining precise @dfn{provenance tracking} of the software.
2611 @node Invoking guix package
2612 @section Invoking @command{guix package}
2614 @cindex installing packages
2615 @cindex removing packages
2616 @cindex package installation
2617 @cindex package removal
2618 The @command{guix package} command is the tool that allows users to
2619 install, upgrade, and remove packages, as well as rolling back to
2620 previous configurations. It operates only on the user's own profile,
2621 and works with normal user privileges (@pxref{Features}). Its syntax
2625 guix package @var{options}
2628 @cindex transactions
2629 Primarily, @var{options} specifies the operations to be performed during
2630 the transaction. Upon completion, a new profile is created, but
2631 previous @dfn{generations} of the profile remain available, should the user
2634 For example, to remove @code{lua} and install @code{guile} and
2635 @code{guile-cairo} in a single transaction:
2638 guix package -r lua -i guile guile-cairo
2641 @cindex aliases, for @command{guix package}
2642 For your convenience, we also provide the following aliases:
2646 @command{guix search} is an alias for @command{guix package -s},
2648 @command{guix install} is an alias for @command{guix package -i},
2650 @command{guix remove} is an alias for @command{guix package -r},
2652 and @command{guix upgrade} is an alias for @command{guix package -u}.
2655 These aliases are less expressive than @command{guix package} and provide
2656 fewer options, so in some cases you'll probably want to use @command{guix
2659 @command{guix package} also supports a @dfn{declarative approach}
2660 whereby the user specifies the exact set of packages to be available and
2661 passes it @i{via} the @option{--manifest} option
2662 (@pxref{profile-manifest, @option{--manifest}}).
2665 For each user, a symlink to the user's default profile is automatically
2666 created in @file{$HOME/.guix-profile}. This symlink always points to the
2667 current generation of the user's default profile. Thus, users can add
2668 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2669 variable, and so on.
2670 @cindex search paths
2671 If you are not using Guix System, consider adding the
2672 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2673 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2674 shells get all the right environment variable definitions:
2677 GUIX_PROFILE="$HOME/.guix-profile" ; \
2678 source "$HOME/.guix-profile/etc/profile"
2681 In a multi-user setup, user profiles are stored in a place registered as
2682 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2683 to (@pxref{Invoking guix gc}). That directory is normally
2684 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2685 @var{localstatedir} is the value passed to @code{configure} as
2686 @code{--localstatedir}, and @var{user} is the user name. The
2687 @file{per-user} directory is created when @command{guix-daemon} is
2688 started, and the @var{user} sub-directory is created by @command{guix
2691 The @var{options} can be among the following:
2695 @item --install=@var{package} @dots{}
2696 @itemx -i @var{package} @dots{}
2697 Install the specified @var{package}s.
2699 Each @var{package} may specify either a simple package name, such as
2700 @code{guile}, or a package name followed by an at-sign and version number,
2701 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2702 case, the newest version prefixed by @code{1.8} is selected.)
2704 If no version number is specified, the
2705 newest available version will be selected. In addition, @var{package}
2706 may contain a colon, followed by the name of one of the outputs of the
2707 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2708 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2709 name (and optionally version) are searched for among the GNU
2710 distribution modules (@pxref{Package Modules}).
2712 @cindex propagated inputs
2713 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2714 that automatically get installed along with the required package
2715 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2716 @code{package} objects}, for information about propagated inputs in
2717 package definitions).
2719 @anchor{package-cmd-propagated-inputs}
2720 An example is the GNU MPC library: its C header files refer to those of
2721 the GNU MPFR library, which in turn refer to those of the GMP library.
2722 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2723 in the profile; removing MPC also removes MPFR and GMP---unless they had
2724 also been explicitly installed by the user.
2726 Besides, packages sometimes rely on the definition of environment
2727 variables for their search paths (see explanation of
2728 @code{--search-paths} below). Any missing or possibly incorrect
2729 environment variable definitions are reported here.
2731 @item --install-from-expression=@var{exp}
2733 Install the package @var{exp} evaluates to.
2735 @var{exp} must be a Scheme expression that evaluates to a
2736 @code{<package>} object. This option is notably useful to disambiguate
2737 between same-named variants of a package, with expressions such as
2738 @code{(@@ (gnu packages base) guile-final)}.
2740 Note that this option installs the first output of the specified
2741 package, which may be insufficient when needing a specific output of a
2742 multiple-output package.
2744 @item --install-from-file=@var{file}
2745 @itemx -f @var{file}
2746 Install the package that the code within @var{file} evaluates to.
2748 As an example, @var{file} might contain a definition like this
2749 (@pxref{Defining Packages}):
2752 @verbatiminclude package-hello.scm
2755 Developers may find it useful to include such a @file{guix.scm} file
2756 in the root of their project source tree that can be used to test
2757 development snapshots and create reproducible development environments
2758 (@pxref{Invoking guix environment}).
2760 @item --remove=@var{package} @dots{}
2761 @itemx -r @var{package} @dots{}
2762 Remove the specified @var{package}s.
2764 As for @code{--install}, each @var{package} may specify a version number
2765 and/or output name in addition to the package name. For instance,
2766 @code{-r glibc:debug} would remove the @code{debug} output of
2769 @item --upgrade[=@var{regexp} @dots{}]
2770 @itemx -u [@var{regexp} @dots{}]
2771 @cindex upgrading packages
2772 Upgrade all the installed packages. If one or more @var{regexp}s are
2773 specified, upgrade only installed packages whose name matches a
2774 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2776 Note that this upgrades package to the latest version of packages found
2777 in the distribution currently installed. To update your distribution,
2778 you should regularly run @command{guix pull} (@pxref{Invoking guix
2781 @item --do-not-upgrade[=@var{regexp} @dots{}]
2782 When used together with the @code{--upgrade} option, do @emph{not}
2783 upgrade any packages whose name matches a @var{regexp}. For example, to
2784 upgrade all packages in the current profile except those containing the
2785 substring ``emacs'':
2788 $ guix package --upgrade . --do-not-upgrade emacs
2791 @item @anchor{profile-manifest}--manifest=@var{file}
2792 @itemx -m @var{file}
2793 @cindex profile declaration
2794 @cindex profile manifest
2795 Create a new generation of the profile from the manifest object
2796 returned by the Scheme code in @var{file}.
2798 This allows you to @emph{declare} the profile's contents rather than
2799 constructing it through a sequence of @code{--install} and similar
2800 commands. The advantage is that @var{file} can be put under version
2801 control, copied to different machines to reproduce the same profile, and
2804 @c FIXME: Add reference to (guix profile) documentation when available.
2805 @var{file} must return a @dfn{manifest} object, which is roughly a list
2808 @findex packages->manifest
2810 (use-package-modules guile emacs)
2815 ;; Use a specific package output.
2816 (list guile-2.0 "debug")))
2819 @findex specifications->manifest
2820 In this example we have to know which modules define the @code{emacs}
2821 and @code{guile-2.0} variables to provide the right
2822 @code{use-package-modules} line, which can be cumbersome. We can
2823 instead provide regular package specifications and let
2824 @code{specifications->manifest} look up the corresponding package
2828 (specifications->manifest
2829 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2833 @cindex rolling back
2834 @cindex undoing transactions
2835 @cindex transactions, undoing
2836 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2837 the last transaction.
2839 When combined with options such as @code{--install}, roll back occurs
2840 before any other actions.
2842 When rolling back from the first generation that actually contains
2843 installed packages, the profile is made to point to the @dfn{zeroth
2844 generation}, which contains no files apart from its own metadata.
2846 After having rolled back, installing, removing, or upgrading packages
2847 overwrites previous future generations. Thus, the history of the
2848 generations in a profile is always linear.
2850 @item --switch-generation=@var{pattern}
2851 @itemx -S @var{pattern}
2853 Switch to a particular generation defined by @var{pattern}.
2855 @var{pattern} may be either a generation number or a number prefixed
2856 with ``+'' or ``-''. The latter means: move forward/backward by a
2857 specified number of generations. For example, if you want to return to
2858 the latest generation after @code{--roll-back}, use
2859 @code{--switch-generation=+1}.
2861 The difference between @code{--roll-back} and
2862 @code{--switch-generation=-1} is that @code{--switch-generation} will
2863 not make a zeroth generation, so if a specified generation does not
2864 exist, the current generation will not be changed.
2866 @item --search-paths[=@var{kind}]
2867 @cindex search paths
2868 Report environment variable definitions, in Bash syntax, that may be
2869 needed in order to use the set of installed packages. These environment
2870 variables are used to specify @dfn{search paths} for files used by some
2871 of the installed packages.
2873 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2874 environment variables to be defined so it can look for headers and
2875 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2876 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2877 library are installed in the profile, then @code{--search-paths} will
2878 suggest setting these variables to @code{@var{profile}/include} and
2879 @code{@var{profile}/lib}, respectively.
2881 The typical use case is to define these environment variables in the
2885 $ eval `guix package --search-paths`
2888 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2889 meaning that the returned environment variable definitions will either
2890 be exact settings, or prefixes or suffixes of the current value of these
2891 variables. When omitted, @var{kind} defaults to @code{exact}.
2893 This option can also be used to compute the @emph{combined} search paths
2894 of several profiles. Consider this example:
2897 $ guix package -p foo -i guile
2898 $ guix package -p bar -i guile-json
2899 $ guix package -p foo -p bar --search-paths
2902 The last command above reports about the @code{GUILE_LOAD_PATH}
2903 variable, even though, taken individually, neither @file{foo} nor
2904 @file{bar} would lead to that recommendation.
2907 @item --profile=@var{profile}
2908 @itemx -p @var{profile}
2909 Use @var{profile} instead of the user's default profile.
2911 @cindex collisions, in a profile
2912 @cindex colliding packages in profiles
2913 @cindex profile collisions
2914 @item --allow-collisions
2915 Allow colliding packages in the new profile. Use at your own risk!
2917 By default, @command{guix package} reports as an error @dfn{collisions}
2918 in the profile. Collisions happen when two or more different versions
2919 or variants of a given package end up in the profile.
2922 Use the bootstrap Guile to build the profile. This option is only
2923 useful to distribution developers.
2927 In addition to these actions, @command{guix package} supports the
2928 following options to query the current state of a profile, or the
2929 availability of packages:
2933 @item --search=@var{regexp}
2934 @itemx -s @var{regexp}
2935 @cindex searching for packages
2936 List the available packages whose name, synopsis, or description matches
2937 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2938 Print all the metadata of matching packages in
2939 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2940 GNU recutils manual}).
2942 This allows specific fields to be extracted using the @command{recsel}
2943 command, for instance:
2946 $ guix package -s malloc | recsel -p name,version,relevance
2960 Similarly, to show the name of all the packages available under the
2961 terms of the GNU@tie{}LGPL version 3:
2964 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2971 It is also possible to refine search results using several @code{-s} flags to
2972 @command{guix package}, or several arguments to @command{guix search}. For
2973 example, the following command returns a list of board games (this time using
2974 the @command{guix search} alias):
2977 $ guix search '\<board\>' game | recsel -p name
2982 If we were to omit @code{-s game}, we would also get software packages
2983 that deal with printed circuit boards; removing the angle brackets
2984 around @code{board} would further add packages that have to do with
2987 And now for a more elaborate example. The following command searches
2988 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2989 libraries, and prints the name and synopsis of the matching packages:
2992 $ guix search crypto library | \
2993 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2997 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2998 information on @dfn{selection expressions} for @code{recsel -e}.
3000 @item --show=@var{package}
3001 Show details about @var{package}, taken from the list of available packages, in
3002 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3006 $ guix package --show=python | recsel -p name,version
3014 You may also specify the full name of a package to only get details about a
3015 specific version of it:
3017 $ guix package --show=python@@3.4 | recsel -p name,version
3024 @item --list-installed[=@var{regexp}]
3025 @itemx -I [@var{regexp}]
3026 List the currently installed packages in the specified profile, with the
3027 most recently installed packages shown last. When @var{regexp} is
3028 specified, list only installed packages whose name matches @var{regexp}.
3030 For each installed package, print the following items, separated by
3031 tabs: the package name, its version string, the part of the package that
3032 is installed (for instance, @code{out} for the default output,
3033 @code{include} for its headers, etc.), and the path of this package in
3036 @item --list-available[=@var{regexp}]
3037 @itemx -A [@var{regexp}]
3038 List packages currently available in the distribution for this system
3039 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3040 installed packages whose name matches @var{regexp}.
3042 For each package, print the following items separated by tabs: its name,
3043 its version string, the parts of the package (@pxref{Packages with
3044 Multiple Outputs}), and the source location of its definition.
3046 @item --list-generations[=@var{pattern}]
3047 @itemx -l [@var{pattern}]
3049 Return a list of generations along with their creation dates; for each
3050 generation, show the installed packages, with the most recently
3051 installed packages shown last. Note that the zeroth generation is never
3054 For each installed package, print the following items, separated by
3055 tabs: the name of a package, its version string, the part of the package
3056 that is installed (@pxref{Packages with Multiple Outputs}), and the
3057 location of this package in the store.
3059 When @var{pattern} is used, the command returns only matching
3060 generations. Valid patterns include:
3063 @item @emph{Integers and comma-separated integers}. Both patterns denote
3064 generation numbers. For instance, @code{--list-generations=1} returns
3067 And @code{--list-generations=1,8,2} outputs three generations in the
3068 specified order. Neither spaces nor trailing commas are allowed.
3070 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3071 specified generations and everything in between. Note that the start of
3072 a range must be smaller than its end.
3074 It is also possible to omit the endpoint. For example,
3075 @code{--list-generations=2..}, returns all generations starting from the
3078 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3079 or months by passing an integer along with the first letter of the
3080 duration. For example, @code{--list-generations=20d} lists generations
3081 that are up to 20 days old.
3084 @item --delete-generations[=@var{pattern}]
3085 @itemx -d [@var{pattern}]
3086 When @var{pattern} is omitted, delete all generations except the current
3089 This command accepts the same patterns as @option{--list-generations}.
3090 When @var{pattern} is specified, delete the matching generations. When
3091 @var{pattern} specifies a duration, generations @emph{older} than the
3092 specified duration match. For instance, @code{--delete-generations=1m}
3093 deletes generations that are more than one month old.
3095 If the current generation matches, it is @emph{not} deleted. Also, the
3096 zeroth generation is never deleted.
3098 Note that deleting generations prevents rolling back to them.
3099 Consequently, this command must be used with care.
3103 Finally, since @command{guix package} may actually start build
3104 processes, it supports all the common build options (@pxref{Common Build
3105 Options}). It also supports package transformation options, such as
3106 @option{--with-source} (@pxref{Package Transformation Options}).
3107 However, note that package transformations are lost when upgrading; to
3108 preserve transformations across upgrades, you should define your own
3109 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3110 (@pxref{Defining Packages}).
3113 @section Substitutes
3116 @cindex pre-built binaries
3117 Guix supports transparent source/binary deployment, which means that it
3118 can either build things locally, or download pre-built items from a
3119 server, or both. We call these pre-built items @dfn{substitutes}---they
3120 are substitutes for local build results. In many cases, downloading a
3121 substitute is much faster than building things locally.
3123 Substitutes can be anything resulting from a derivation build
3124 (@pxref{Derivations}). Of course, in the common case, they are
3125 pre-built package binaries, but source tarballs, for instance, which
3126 also result from derivation builds, can be available as substitutes.
3129 * Official Substitute Server:: One particular source of substitutes.
3130 * Substitute Server Authorization:: How to enable or disable substitutes.
3131 * Substitute Authentication:: How Guix verifies substitutes.
3132 * Proxy Settings:: How to get substitutes via proxy.
3133 * Substitution Failure:: What happens when substitution fails.
3134 * On Trusting Binaries:: How can you trust that binary blob?
3137 @node Official Substitute Server
3138 @subsection Official Substitute Server
3141 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3142 that builds packages from Guix continuously for some
3143 architectures, and makes them available as substitutes. This is the
3144 default source of substitutes; it can be overridden by passing the
3145 @option{--substitute-urls} option either to @command{guix-daemon}
3146 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3147 or to client tools such as @command{guix package}
3148 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3151 Substitute URLs can be either HTTP or HTTPS.
3152 HTTPS is recommended because communications are encrypted; conversely,
3153 using HTTP makes all communications visible to an eavesdropper, who
3154 could use the information gathered to determine, for instance, whether
3155 your system has unpatched security vulnerabilities.
3157 Substitutes from the official build farm are enabled by default when
3158 using Guix System (@pxref{GNU Distribution}). However,
3159 they are disabled by default when using Guix on a foreign distribution,
3160 unless you have explicitly enabled them via one of the recommended
3161 installation steps (@pxref{Installation}). The following paragraphs
3162 describe how to enable or disable substitutes for the official build
3163 farm; the same procedure can also be used to enable substitutes for any
3164 other substitute server.
3166 @node Substitute Server Authorization
3167 @subsection Substitute Server Authorization
3170 @cindex substitutes, authorization thereof
3171 @cindex access control list (ACL), for substitutes
3172 @cindex ACL (access control list), for substitutes
3173 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3175 must add its public key to the access control list (ACL) of archive
3176 imports, using the @command{guix archive} command (@pxref{Invoking guix
3177 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3178 be compromised and to serve genuine substitutes.
3180 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3181 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3182 the installation prefix of Guix. If you installed Guix from source,
3183 make sure you checked the GPG signature of
3184 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3185 Then, you can run something like this:
3188 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3191 Once this is in place, the output of a command like @code{guix build}
3192 should change from something like:
3195 $ guix build emacs --dry-run
3196 The following derivations would be built:
3197 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3198 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3199 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3200 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3208 $ guix build emacs --dry-run
3209 112.3 MB would be downloaded:
3210 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3211 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3212 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3213 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3218 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3219 will be downloaded, when possible, for future builds.
3221 @cindex substitutes, how to disable
3222 The substitute mechanism can be disabled globally by running
3223 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3224 guix-daemon}). It can also be disabled temporarily by passing the
3225 @code{--no-substitutes} option to @command{guix package}, @command{guix
3226 build}, and other command-line tools.
3228 @node Substitute Authentication
3229 @subsection Substitute Authentication
3231 @cindex digital signatures
3232 Guix detects and raises an error when attempting to use a substitute
3233 that has been tampered with. Likewise, it ignores substitutes that are
3234 not signed, or that are not signed by one of the keys listed in the ACL.
3236 There is one exception though: if an unauthorized server provides
3237 substitutes that are @emph{bit-for-bit identical} to those provided by
3238 an authorized server, then the unauthorized server becomes eligible for
3239 downloads. For example, assume we have chosen two substitute servers
3243 --substitute-urls="https://a.example.org https://b.example.org"
3247 @cindex reproducible builds
3248 If the ACL contains only the key for @code{b.example.org}, and if
3249 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3250 then Guix will download substitutes from @code{a.example.org} because it
3251 comes first in the list and can be considered a mirror of
3252 @code{b.example.org}. In practice, independent build machines usually
3253 produce the same binaries, thanks to bit-reproducible builds (see
3256 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3257 (in other words, the server is not authenticated), contrary to what
3258 HTTPS clients such as Web browsers usually do. This is because Guix
3259 authenticates substitute information itself, as explained above, which
3260 is what we care about (whereas X.509 certificates are about
3261 authenticating bindings between domain names and public keys.)
3263 @node Proxy Settings
3264 @subsection Proxy Settings
3267 Substitutes are downloaded over HTTP or HTTPS.
3268 The @code{http_proxy} environment
3269 variable can be set in the environment of @command{guix-daemon} and is
3270 honored for downloads of substitutes. Note that the value of
3271 @code{http_proxy} in the environment where @command{guix build},
3272 @command{guix package}, and other client commands are run has
3273 @emph{absolutely no effect}.
3275 @node Substitution Failure
3276 @subsection Substitution Failure
3278 Even when a substitute for a derivation is available, sometimes the
3279 substitution attempt will fail. This can happen for a variety of
3280 reasons: the substitute server might be offline, the substitute may
3281 recently have been deleted, the connection might have been interrupted,
3284 When substitutes are enabled and a substitute for a derivation is
3285 available, but the substitution attempt fails, Guix will attempt to
3286 build the derivation locally depending on whether or not
3287 @code{--fallback} was given (@pxref{fallback-option,, common build
3288 option @code{--fallback}}). Specifically, if @code{--fallback} was
3289 omitted, then no local build will be performed, and the derivation is
3290 considered to have failed. However, if @code{--fallback} was given,
3291 then Guix will attempt to build the derivation locally, and the success
3292 or failure of the derivation depends on the success or failure of the
3293 local build. Note that when substitutes are disabled or no substitute
3294 is available for the derivation in question, a local build will
3295 @emph{always} be performed, regardless of whether or not
3296 @code{--fallback} was given.
3298 To get an idea of how many substitutes are available right now, you can
3299 try running the @command{guix weather} command (@pxref{Invoking guix
3300 weather}). This command provides statistics on the substitutes provided
3303 @node On Trusting Binaries
3304 @subsection On Trusting Binaries
3306 @cindex trust, of pre-built binaries
3307 Today, each individual's control over their own computing is at the
3308 mercy of institutions, corporations, and groups with enough power and
3309 determination to subvert the computing infrastructure and exploit its
3310 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3311 convenient, we encourage users to also build on their own, or even run
3312 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3313 interesting target. One way to help is by publishing the software you
3314 build using @command{guix publish} so that others have one more choice
3315 of server to download substitutes from (@pxref{Invoking guix publish}).
3317 Guix has the foundations to maximize build reproducibility
3318 (@pxref{Features}). In most cases, independent builds of a given
3319 package or derivation should yield bit-identical results. Thus, through
3320 a diverse set of independent package builds, we can strengthen the
3321 integrity of our systems. The @command{guix challenge} command aims to
3322 help users assess substitute servers, and to assist developers in
3323 finding out about non-deterministic package builds (@pxref{Invoking guix
3324 challenge}). Similarly, the @option{--check} option of @command{guix
3325 build} allows users to check whether previously-installed substitutes
3326 are genuine by rebuilding them locally (@pxref{build-check,
3327 @command{guix build --check}}).
3329 In the future, we want Guix to have support to publish and retrieve
3330 binaries to/from other users, in a peer-to-peer fashion. If you would
3331 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3333 @node Packages with Multiple Outputs
3334 @section Packages with Multiple Outputs
3336 @cindex multiple-output packages
3337 @cindex package outputs
3340 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3341 source package leads to exactly one directory in the store. When running
3342 @command{guix install glibc}, one installs the default output of the
3343 GNU libc package; the default output is called @code{out}, but its name
3344 can be omitted as shown in this command. In this particular case, the
3345 default output of @code{glibc} contains all the C header files, shared
3346 libraries, static libraries, Info documentation, and other supporting
3349 Sometimes it is more appropriate to separate the various types of files
3350 produced from a single source package into separate outputs. For
3351 instance, the GLib C library (used by GTK+ and related packages)
3352 installs more than 20 MiB of reference documentation as HTML pages.
3353 To save space for users who do not need it, the documentation goes to a
3354 separate output, called @code{doc}. To install the main GLib output,
3355 which contains everything but the documentation, one would run:
3361 @cindex documentation
3362 The command to install its documentation is:
3365 guix install glib:doc
3368 Some packages install programs with different ``dependency footprints''.
3369 For instance, the WordNet package installs both command-line tools and
3370 graphical user interfaces (GUIs). The former depend solely on the C
3371 library, whereas the latter depend on Tcl/Tk and the underlying X
3372 libraries. In this case, we leave the command-line tools in the default
3373 output, whereas the GUIs are in a separate output. This allows users
3374 who do not need the GUIs to save space. The @command{guix size} command
3375 can help find out about such situations (@pxref{Invoking guix size}).
3376 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3378 There are several such multiple-output packages in the GNU distribution.
3379 Other conventional output names include @code{lib} for libraries and
3380 possibly header files, @code{bin} for stand-alone programs, and
3381 @code{debug} for debugging information (@pxref{Installing Debugging
3382 Files}). The outputs of a packages are listed in the third column of
3383 the output of @command{guix package --list-available} (@pxref{Invoking
3387 @node Invoking guix gc
3388 @section Invoking @command{guix gc}
3390 @cindex garbage collector
3392 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3393 The @command{guix gc} command allows users to explicitly run the garbage
3394 collector to reclaim space from the @file{/gnu/store} directory. It is
3395 the @emph{only} way to remove files from @file{/gnu/store}---removing
3396 files or directories manually may break it beyond repair!
3399 @cindex garbage collector roots
3400 The garbage collector has a set of known @dfn{roots}: any file under
3401 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3402 cannot be deleted; any other file is considered @dfn{dead} and may be
3403 deleted. The set of garbage collector roots (``GC roots'' for short)
3404 includes default user profiles; by default, the symlinks under
3405 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3406 added with @command{guix build --root}, for example (@pxref{Invoking
3407 guix build}). The @command{guix gc --list-roots} command lists them.
3409 Prior to running @code{guix gc --collect-garbage} to make space, it is
3410 often useful to remove old generations from user profiles; that way, old
3411 package builds referenced by those generations can be reclaimed. This
3412 is achieved by running @code{guix package --delete-generations}
3413 (@pxref{Invoking guix package}).
3415 Our recommendation is to run a garbage collection periodically, or when
3416 you are short on disk space. For instance, to guarantee that at least
3417 5@tie{}GB are available on your disk, simply run:
3423 It is perfectly safe to run as a non-interactive periodic job
3424 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3425 Running @command{guix gc} with no arguments will collect as
3426 much garbage as it can, but that is often inconvenient: you may find
3427 yourself having to rebuild or re-download software that is ``dead'' from
3428 the GC viewpoint but that is necessary to build other pieces of
3429 software---e.g., the compiler tool chain.
3431 The @command{guix gc} command has three modes of operation: it can be
3432 used to garbage-collect any dead files (the default), to delete specific
3433 files (the @code{--delete} option), to print garbage-collector
3434 information, or for more advanced queries. The garbage collection
3435 options are as follows:
3438 @item --collect-garbage[=@var{min}]
3439 @itemx -C [@var{min}]
3440 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3441 sub-directories. This is the default operation when no option is
3444 When @var{min} is given, stop once @var{min} bytes have been collected.
3445 @var{min} may be a number of bytes, or it may include a unit as a
3446 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3447 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3449 When @var{min} is omitted, collect all the garbage.
3451 @item --free-space=@var{free}
3452 @itemx -F @var{free}
3453 Collect garbage until @var{free} space is available under
3454 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3455 as @code{500MiB}, as described above.
3457 When @var{free} or more is already available in @file{/gnu/store}, do
3458 nothing and exit immediately.
3460 @item --delete-generations[=@var{duration}]
3461 @itemx -d [@var{duration}]
3462 Before starting the garbage collection process, delete all the generations
3463 older than @var{duration}, for all the user profiles; when run as root, this
3464 applies to all the profiles @emph{of all the users}.
3466 For example, this command deletes all the generations of all your profiles
3467 that are older than 2 months (except generations that are current), and then
3468 proceeds to free space until at least 10 GiB are available:
3471 guix gc -d 2m -F 10G
3476 Attempt to delete all the store files and directories specified as
3477 arguments. This fails if some of the files are not in the store, or if
3478 they are still live.
3480 @item --list-failures
3481 List store items corresponding to cached build failures.
3483 This prints nothing unless the daemon was started with
3484 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3485 @option{--cache-failures}}).
3488 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3491 @item --clear-failures
3492 Remove the specified store items from the failed-build cache.
3494 Again, this option only makes sense when the daemon is started with
3495 @option{--cache-failures}. Otherwise, it does nothing.
3498 Show the list of dead files and directories still present in the
3499 store---i.e., files and directories no longer reachable from any root.
3502 Show the list of live store files and directories.
3506 In addition, the references among existing store files can be queried:
3512 @cindex package dependencies
3513 List the references (respectively, the referrers) of store files given
3519 List the requisites of the store files passed as arguments. Requisites
3520 include the store files themselves, their references, and the references
3521 of these, recursively. In other words, the returned list is the
3522 @dfn{transitive closure} of the store files.
3524 @xref{Invoking guix size}, for a tool to profile the size of the closure
3525 of an element. @xref{Invoking guix graph}, for a tool to visualize
3526 the graph of references.
3530 Return the derivation(s) leading to the given store items
3531 (@pxref{Derivations}).
3533 For example, this command:
3536 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3540 returns the @file{.drv} file(s) leading to the @code{emacs} package
3541 installed in your profile.
3543 Note that there may be zero matching @file{.drv} files, for instance
3544 because these files have been garbage-collected. There can also be more
3545 than one matching @file{.drv} due to fixed-output derivations.
3548 Lastly, the following options allow you to check the integrity of the
3549 store and to control disk usage.
3553 @item --verify[=@var{options}]
3554 @cindex integrity, of the store
3555 @cindex integrity checking
3556 Verify the integrity of the store.
3558 By default, make sure that all the store items marked as valid in the
3559 database of the daemon actually exist in @file{/gnu/store}.
3561 When provided, @var{options} must be a comma-separated list containing one
3562 or more of @code{contents} and @code{repair}.
3564 When passing @option{--verify=contents}, the daemon computes the
3565 content hash of each store item and compares it against its hash in the
3566 database. Hash mismatches are reported as data corruptions. Because it
3567 traverses @emph{all the files in the store}, this command can take a
3568 long time, especially on systems with a slow disk drive.
3570 @cindex repairing the store
3571 @cindex corruption, recovering from
3572 Using @option{--verify=repair} or @option{--verify=contents,repair}
3573 causes the daemon to try to repair corrupt store items by fetching
3574 substitutes for them (@pxref{Substitutes}). Because repairing is not
3575 atomic, and thus potentially dangerous, it is available only to the
3576 system administrator. A lightweight alternative, when you know exactly
3577 which items in the store are corrupt, is @command{guix build --repair}
3578 (@pxref{Invoking guix build}).
3581 @cindex deduplication
3582 Optimize the store by hard-linking identical files---this is
3583 @dfn{deduplication}.
3585 The daemon performs deduplication after each successful build or archive
3586 import, unless it was started with @code{--disable-deduplication}
3587 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3588 this option is primarily useful when the daemon was running with
3589 @code{--disable-deduplication}.
3593 @node Invoking guix pull
3594 @section Invoking @command{guix pull}
3596 @cindex upgrading Guix
3597 @cindex updating Guix
3598 @cindex @command{guix pull}
3600 Packages are installed or upgraded to the latest version available in
3601 the distribution currently available on your local machine. To update
3602 that distribution, along with the Guix tools, you must run @command{guix
3603 pull}: the command downloads the latest Guix source code and package
3604 descriptions, and deploys it. Source code is downloaded from a
3605 @uref{https://git-scm.com, Git} repository, by default the official
3606 GNU@tie{}Guix repository, though this can be customized.
3608 On completion, @command{guix package} will use packages and package
3609 versions from this just-retrieved copy of Guix. Not only that, but all
3610 the Guix commands and Scheme modules will also be taken from that latest
3611 version. New @command{guix} sub-commands added by the update also
3614 Any user can update their Guix copy using @command{guix pull}, and the
3615 effect is limited to the user who run @command{guix pull}. For
3616 instance, when user @code{root} runs @command{guix pull}, this has no
3617 effect on the version of Guix that user @code{alice} sees, and vice
3620 The result of running @command{guix pull} is a @dfn{profile} available
3621 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3622 make sure to add it to the beginning of your search path so that you use
3623 the latest version, and similarly for the Info manual
3624 (@pxref{Documentation}):
3627 export PATH="$HOME/.config/guix/current/bin:$PATH"
3628 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3631 The @code{--list-generations} or @code{-l} option lists past generations
3632 produced by @command{guix pull}, along with details about their provenance:
3636 Generation 1 Jun 10 2018 00:18:18
3638 repository URL: https://git.savannah.gnu.org/git/guix.git
3639 branch: origin/master
3640 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3642 Generation 2 Jun 11 2018 11:02:49
3644 repository URL: https://git.savannah.gnu.org/git/guix.git
3645 branch: origin/master
3646 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3647 2 new packages: keepalived, libnfnetlink
3648 6 packages upgraded: emacs-nix-mode@@2.0.4,
3649 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3650 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3652 Generation 3 Jun 13 2018 23:31:07 (current)
3654 repository URL: https://git.savannah.gnu.org/git/guix.git
3655 branch: origin/master
3656 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3657 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3658 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3661 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3662 describe the current status of Guix.
3664 This @code{~/.config/guix/current} profile works like any other profile
3665 created by @command{guix package} (@pxref{Invoking guix package}). That
3666 is, you can list generations, roll back to the previous
3667 generation---i.e., the previous Guix---and so on:
3670 $ guix package -p ~/.config/guix/current --roll-back
3671 switched from generation 3 to 2
3672 $ guix package -p ~/.config/guix/current --delete-generations=1
3673 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3676 The @command{guix pull} command is usually invoked with no arguments,
3677 but it supports the following options:
3680 @item --url=@var{url}
3681 @itemx --commit=@var{commit}
3682 @itemx --branch=@var{branch}
3683 Download code for the @code{guix} channel from the specified @var{url}, at the
3684 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3685 string), or @var{branch}.
3687 @cindex @file{channels.scm}, configuration file
3688 @cindex configuration file for channels
3689 These options are provided for convenience, but you can also specify your
3690 configuration in the @file{~/.config/guix/channels.scm} file or using the
3691 @option{--channels} option (see below).
3693 @item --channels=@var{file}
3694 @itemx -C @var{file}
3695 Read the list of channels from @var{file} instead of
3696 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3697 evaluates to a list of channel objects. @xref{Channels}, for more
3702 Display the list of packages added or upgraded since the previous generation.
3704 This is the same information as displayed upon @command{guix pull} completion,
3705 but without ellipses; it is also similar to the output of @command{guix pull
3706 -l} for the last generation (see below).
3708 @item --list-generations[=@var{pattern}]
3709 @itemx -l [@var{pattern}]
3710 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3711 is provided, the subset of generations that match @var{pattern}.
3712 The syntax of @var{pattern} is the same as with @code{guix package
3713 --list-generations} (@pxref{Invoking guix package}).
3715 @xref{Invoking guix describe}, for a way to display information about the
3716 current generation only.
3718 @item --profile=@var{profile}
3719 @itemx -p @var{profile}
3720 Use @var{profile} instead of @file{~/.config/guix/current}.
3724 Show which channel commit(s) would be used and what would be built or
3725 substituted but do not actually do it.
3727 @item --system=@var{system}
3728 @itemx -s @var{system}
3729 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3730 the system type of the build host.
3733 Produce verbose output, writing build logs to the standard error output.
3736 Use the bootstrap Guile to build the latest Guix. This option is only
3737 useful to Guix developers.
3740 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3741 repository and branch to pull from, as well as @emph{additional} repositories
3742 containing package modules that should be deployed. @xref{Channels}, for more
3745 In addition, @command{guix pull} supports all the common build options
3746 (@pxref{Common Build Options}).
3752 @cindex @file{channels.scm}, configuration file
3753 @cindex configuration file for channels
3754 @cindex @command{guix pull}, configuration file
3755 @cindex configuration of @command{guix pull}
3756 Guix and its package collection are updated by running @command{guix pull}
3757 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3758 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3759 customized by defining @dfn{channels} in the
3760 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3761 of a Git repository to be deployed, and @command{guix pull} can be instructed
3762 to pull from one or more channels. In other words, channels can be used to
3763 @emph{customize} and to @emph{extend} Guix, as we will see below.
3765 @subsection Using a Custom Guix Channel
3767 The channel called @code{guix} specifies where Guix itself---its command-line
3768 tools as well as its package collection---should be downloaded. For instance,
3769 suppose you want to update from your own copy of the Guix repository at
3770 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3771 write in @code{~/.config/guix/channels.scm} this specification:
3774 ;; Tell 'guix pull' to use my own repo.
3777 (url "https://example.org/my-guix.git")
3778 (branch "super-hacks")))
3782 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3783 branch of the repository at @code{example.org}.
3785 @subsection Specifying Additional Channels
3787 @cindex extending the package collection (channels)
3788 @cindex personal packages (channels)
3789 @cindex channels, for personal packages
3790 You can also specify @emph{additional channels} to pull from. Let's say you
3791 have a bunch of custom package variants or personal packages that you think
3792 would make little sense to contribute to the Guix project, but would like to
3793 have these packages transparently available to you at the command line. You
3794 would first write modules containing those package definitions (@pxref{Package
3795 Modules}), maintain them in a Git repository, and then you and anyone else can
3796 use it as an additional channel to get packages from. Neat, no?
3798 @c What follows stems from discussions at
3799 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3800 @c earlier discussions on guix-devel@gnu.org.
3802 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3803 publish your personal channel to the world, we would like to share a few words
3808 Before publishing a channel, please consider contributing your package
3809 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3810 to free software of all sorts, and packages in Guix proper are readily
3811 available to all Guix users and benefit from the project's quality assurance
3815 When you maintain package definitions outside Guix, we, Guix developers,
3816 consider that @emph{the compatibility burden is on you}. Remember that
3817 package modules and package definitions are just Scheme code that uses various
3818 programming interfaces (APIs). We want to remain free to change these APIs to
3819 keep improving Guix, possibly in ways that break your channel. We never
3820 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3824 Corollary: if you're using an external channel and that channel breaks, please
3825 @emph{report the issue to the channel authors}, not to the Guix project.
3828 You've been warned! Having said this, we believe external channels are a
3829 practical way to exert your freedom to augment Guix' package collection and to
3830 share your improvements, which are basic tenets of
3831 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3832 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3835 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3836 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3839 @vindex %default-channels
3841 ;; Add my personal packages to those Guix provides.
3843 (name 'my-personal-packages)
3844 (url "https://example.org/personal-packages.git"))
3849 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3850 add a channel the list of channels that the variable @code{%default-channels}
3851 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3852 Manual}). With this file in place, @command{guix pull} builds not only Guix
3853 but also the package modules from your own repository. The result in
3854 @file{~/.config/guix/current} is the union of Guix with your own package
3858 $ guix pull --list-generations
3860 Generation 19 Aug 27 2018 16:20:48
3862 repository URL: https://git.savannah.gnu.org/git/guix.git
3864 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3865 my-personal-packages dd3df5e
3866 repository URL: https://example.org/personal-packages.git
3868 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3869 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3870 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3874 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3875 both Guix and packages from the @code{my-personal-packages} channel. Among
3876 the new and upgraded packages that are listed, some like @code{my-gimp} and
3877 @code{my-emacs-with-cool-features} might come from
3878 @code{my-personal-packages}, while others come from the Guix default channel.
3880 To create a channel, create a Git repository containing your own package
3881 modules and make it available. The repository can contain anything, but a
3882 useful channel will contain Guile modules that export packages. Once you
3883 start using a channel, Guix will behave as if the root directory of that
3884 channel's Git repository has been added to the Guile load path (@pxref{Load
3885 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3886 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3887 module, then the module will be available under the name @code{(my-packages
3888 my-tools)}, and you will be able to use it like any other module
3889 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3891 @cindex dependencies, channels
3892 @cindex meta-data, channels
3893 @subsection Declaring Channel Dependencies
3895 Channel authors may decide to augment a package collection provided by other
3896 channels. They can declare their channel to be dependent on other channels in
3897 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3898 the channel repository.
3900 The meta-data file should contain a simple S-expression like this:
3907 (name some-collection)
3908 (url "https://example.org/first-collection.git"))
3910 (name some-other-collection)
3911 (url "https://example.org/second-collection.git")
3912 (branch "testing"))))
3915 In the above example this channel is declared to depend on two other channels,
3916 which will both be fetched automatically. The modules provided by the channel
3917 will be compiled in an environment where the modules of all these declared
3918 channels are available.
3920 For the sake of reliability and maintainability, you should avoid dependencies
3921 on channels that you don't control, and you should aim to keep the number of
3922 dependencies to a minimum.
3924 @cindex subdirectory, channels
3925 @subsection Package Modules in a Sub-directory
3927 As a channel author, you may want to keep your channel modules in a
3928 sub-directory. If your modules are in the sub-directory @file{guix}, you must
3929 add a meta-data file @file{.guix-channel} that contains:
3937 @subsection Replicating Guix
3939 @cindex pinning, channels
3940 @cindex replicating Guix
3941 @cindex reproducibility, of Guix
3942 The @command{guix pull --list-generations} output above shows precisely which
3943 commits were used to build this instance of Guix. We can thus replicate it,
3944 say, on another machine, by providing a channel specification in
3945 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3948 ;; Deploy specific commits of my channels of interest.
3951 (url "https://git.savannah.gnu.org/git/guix.git")
3952 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3954 (name 'my-personal-packages)
3955 (url "https://example.org/personal-packages.git")
3956 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3959 The @command{guix describe --format=channels} command can even generate this
3960 list of channels directly (@pxref{Invoking guix describe}).
3962 At this point the two machines run the @emph{exact same Guix}, with access to
3963 the @emph{exact same packages}. The output of @command{guix build gimp} on
3964 one machine will be exactly the same, bit for bit, as the output of the same
3965 command on the other machine. It also means both machines have access to all
3966 the source code of Guix and, transitively, to all the source code of every
3969 This gives you super powers, allowing you to track the provenance of binary
3970 artifacts with very fine grain, and to reproduce software environments at
3971 will---some sort of ``meta reproducibility'' capabilities, if you will.
3972 @xref{Inferiors}, for another way to take advantage of these super powers.
3977 @c TODO: Remove this once we're more confident about API stability.
3979 The functionality described here is a ``technology preview'' as of version
3980 @value{VERSION}. As such, the interface is subject to change.
3984 @cindex composition of Guix revisions
3985 Sometimes you might need to mix packages from the revision of Guix you're
3986 currently running with packages available in a different revision of Guix.
3987 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3988 revisions in arbitrary ways.
3990 @cindex inferior packages
3991 Technically, an ``inferior'' is essentially a separate Guix process connected
3992 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3993 @code{(guix inferior)} module allows you to create inferiors and to
3994 communicate with them. It also provides a high-level interface to browse and
3995 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3997 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3998 to interact with a separate revision of Guix. For example, let's assume you
3999 want to install in your profile the current @code{guile} package, along with
4000 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4001 because the newer @code{guile-json} has an incompatible API and you want to
4002 run your code against the old API@. To do that, you could write a manifest for
4003 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4004 manifest, you would create an inferior for that old Guix revision you care
4005 about, and you would look up the @code{guile-json} package in the inferior:
4008 (use-modules (guix inferior) (guix channels)
4009 (srfi srfi-1)) ;for 'first'
4012 ;; This is the old revision from which we want to
4013 ;; extract guile-json.
4016 (url "https://git.savannah.gnu.org/git/guix.git")
4018 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4021 ;; An inferior representing the above revision.
4022 (inferior-for-channels channels))
4024 ;; Now create a manifest with the current "guile" package
4025 ;; and the old "guile-json" package.
4027 (list (first (lookup-inferior-packages inferior "guile-json"))
4028 (specification->package "guile")))
4031 On its first run, @command{guix package --manifest} might have to build the
4032 channel you specified before it can create the inferior; subsequent runs will
4033 be much faster because the Guix revision will be cached.
4035 The @code{(guix inferior)} module provides the following procedures to open an
4038 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4039 [#:cache-directory] [#:ttl]
4040 Return an inferior for @var{channels}, a list of channels. Use the cache at
4041 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4042 This procedure opens a new connection to the build daemon.
4044 As a side effect, this procedure may build or substitute binaries for
4045 @var{channels}, which can take time.
4048 @deffn {Scheme Procedure} open-inferior @var{directory} @
4049 [#:command "bin/guix"]
4050 Open the inferior Guix in @var{directory}, running
4051 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4052 the inferior could not be launched.
4055 @cindex inferior packages
4056 The procedures listed below allow you to obtain and manipulate inferior
4059 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4060 Return the list of packages known to @var{inferior}.
4063 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4065 Return the sorted list of inferior packages matching @var{name} in
4066 @var{inferior}, with highest version numbers first. If @var{version} is true,
4067 return only packages with a version number prefixed by @var{version}.
4070 @deffn {Scheme Procedure} inferior-package? @var{obj}
4071 Return true if @var{obj} is an inferior package.
4074 @deffn {Scheme Procedure} inferior-package-name @var{package}
4075 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4076 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4077 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4078 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4079 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4080 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4081 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4082 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4083 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4084 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4085 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4086 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4087 These procedures are the counterpart of package record accessors
4088 (@pxref{package Reference}). Most of them work by querying the inferior
4089 @var{package} comes from, so the inferior must still be live when you call
4093 Inferior packages can be used transparently like any other package or
4094 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4095 transparently handled by the @code{packages->manifest} procedure, which is
4096 commonly use in manifests (@pxref{Invoking guix package, the
4097 @option{--manifest} option of @command{guix package}}). Thus you can insert
4098 an inferior package pretty much anywhere you would insert a regular package:
4099 in manifests, in the @code{packages} field of your @code{operating-system}
4100 declaration, and so on.
4102 @node Invoking guix describe
4103 @section Invoking @command{guix describe}
4105 @cindex reproducibility
4106 @cindex replicating Guix
4107 Often you may want to answer questions like: ``Which revision of Guix am I
4108 using?'' or ``Which channels am I using?'' This is useful information in many
4109 situations: if you want to @emph{replicate} an environment on a different
4110 machine or user account, if you want to report a bug or to determine what
4111 change in the channels you are using caused it, or if you want to record your
4112 system state for reproducibility purposes. The @command{guix describe}
4113 command answers these questions.
4115 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4116 displays the channel(s) that it was built from, including their repository URL
4117 and commit IDs (@pxref{Channels}):
4121 Generation 10 Sep 03 2018 17:32:44 (current)
4123 repository URL: https://git.savannah.gnu.org/git/guix.git
4125 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4128 If you're familiar with the Git version control system, this is similar in
4129 spirit to @command{git describe}; the output is also similar to that of
4130 @command{guix pull --list-generations}, but limited to the current generation
4131 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4132 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4133 information is all it takes to describe the revision of Guix you're using, and
4134 also to replicate it.
4136 To make it easier to replicate Guix, @command{guix describe} can also be asked
4137 to return a list of channels instead of the human-readable description above:
4140 $ guix describe -f channels
4143 (url "https://git.savannah.gnu.org/git/guix.git")
4145 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4149 You can save this to a file and feed it to @command{guix pull -C} on some
4150 other machine or at a later point in time, which will instantiate @emph{this
4151 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4152 From there on, since you're able to deploy the same revision of Guix, you can
4153 just as well @emph{replicate a complete software environment}. We humbly
4154 think that this is @emph{awesome}, and we hope you'll like it too!
4156 The details of the options supported by @command{guix describe} are as
4160 @item --format=@var{format}
4161 @itemx -f @var{format}
4162 Produce output in the specified @var{format}, one of:
4166 produce human-readable output;
4168 produce a list of channel specifications that can be passed to @command{guix
4169 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4173 produce a list of channel specifications in JSON format;
4175 produce a list of channel specifications in Recutils format.
4178 @item --profile=@var{profile}
4179 @itemx -p @var{profile}
4180 Display information about @var{profile}.
4183 @node Invoking guix archive
4184 @section Invoking @command{guix archive}
4186 @cindex @command{guix archive}
4188 The @command{guix archive} command allows users to @dfn{export} files
4189 from the store into a single archive, and to later @dfn{import} them on
4190 a machine that runs Guix.
4191 In particular, it allows store files to be transferred from one machine
4192 to the store on another machine.
4195 If you're looking for a way to produce archives in a format suitable for
4196 tools other than Guix, @pxref{Invoking guix pack}.
4199 @cindex exporting store items
4200 To export store files as an archive to standard output, run:
4203 guix archive --export @var{options} @var{specifications}...
4206 @var{specifications} may be either store file names or package
4207 specifications, as for @command{guix package} (@pxref{Invoking guix
4208 package}). For instance, the following command creates an archive
4209 containing the @code{gui} output of the @code{git} package and the main
4210 output of @code{emacs}:
4213 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4216 If the specified packages are not built yet, @command{guix archive}
4217 automatically builds them. The build process may be controlled with the
4218 common build options (@pxref{Common Build Options}).
4220 To transfer the @code{emacs} package to a machine connected over SSH,
4224 guix archive --export -r emacs | ssh the-machine guix archive --import
4228 Similarly, a complete user profile may be transferred from one machine
4229 to another like this:
4232 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4233 ssh the-machine guix archive --import
4237 However, note that, in both examples, all of @code{emacs} and the
4238 profile as well as all of their dependencies are transferred (due to
4239 @code{-r}), regardless of what is already available in the store on the
4240 target machine. The @code{--missing} option can help figure out which
4241 items are missing from the target store. The @command{guix copy}
4242 command simplifies and optimizes this whole process, so this is probably
4243 what you should use in this case (@pxref{Invoking guix copy}).
4245 @cindex nar, archive format
4246 @cindex normalized archive (nar)
4247 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4248 comparable in spirit to `tar', but with differences
4249 that make it more appropriate for our purposes. First, rather than
4250 recording all Unix metadata for each file, the nar format only mentions
4251 the file type (regular, directory, or symbolic link); Unix permissions
4252 and owner/group are dismissed. Second, the order in which directory
4253 entries are stored always follows the order of file names according to
4254 the C locale collation order. This makes archive production fully
4257 When exporting, the daemon digitally signs the contents of the archive,
4258 and that digital signature is appended. When importing, the daemon
4259 verifies the signature and rejects the import in case of an invalid
4260 signature or if the signing key is not authorized.
4261 @c FIXME: Add xref to daemon doc about signatures.
4263 The main options are:
4267 Export the specified store files or packages (see below.) Write the
4268 resulting archive to the standard output.
4270 Dependencies are @emph{not} included in the output, unless
4271 @code{--recursive} is passed.
4275 When combined with @code{--export}, this instructs @command{guix
4276 archive} to include dependencies of the given items in the archive.
4277 Thus, the resulting archive is self-contained: it contains the closure
4278 of the exported store items.
4281 Read an archive from the standard input, and import the files listed
4282 therein into the store. Abort if the archive has an invalid digital
4283 signature, or if it is signed by a public key not among the authorized
4284 keys (see @code{--authorize} below.)
4287 Read a list of store file names from the standard input, one per line,
4288 and write on the standard output the subset of these files missing from
4291 @item --generate-key[=@var{parameters}]
4292 @cindex signing, archives
4293 Generate a new key pair for the daemon. This is a prerequisite before
4294 archives can be exported with @code{--export}. Note that this operation
4295 usually takes time, because it needs to gather enough entropy to
4296 generate the key pair.
4298 The generated key pair is typically stored under @file{/etc/guix}, in
4299 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4300 key, which must be kept secret.) When @var{parameters} is omitted,
4301 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4302 versions before 1.6.0, it is a 4096-bit RSA key.
4303 Alternatively, @var{parameters} can specify
4304 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4305 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4306 Libgcrypt Reference Manual}).
4309 @cindex authorizing, archives
4310 Authorize imports signed by the public key passed on standard input.
4311 The public key must be in ``s-expression advanced format''---i.e., the
4312 same format as the @file{signing-key.pub} file.
4314 The list of authorized keys is kept in the human-editable file
4315 @file{/etc/guix/acl}. The file contains
4316 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4317 s-expressions''} and is structured as an access-control list in the
4318 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4321 @item --extract=@var{directory}
4322 @itemx -x @var{directory}
4323 Read a single-item archive as served by substitute servers
4324 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4325 low-level operation needed in only very narrow use cases; see below.
4327 For example, the following command extracts the substitute for Emacs
4328 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4332 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4333 | bunzip2 | guix archive -x /tmp/emacs
4336 Single-item archives are different from multiple-item archives produced
4337 by @command{guix archive --export}; they contain a single store item,
4338 and they do @emph{not} embed a signature. Thus this operation does
4339 @emph{no} signature verification and its output should be considered
4342 The primary purpose of this operation is to facilitate inspection of
4343 archive contents coming from possibly untrusted substitute servers.
4348 @c *********************************************************************
4350 @chapter Development
4352 @cindex software development
4353 If you are a software developer, Guix provides tools that you should find
4354 helpful---independently of the language you're developing in. This is what
4355 this chapter is about.
4357 The @command{guix environment} command provides a convenient way to set up
4358 @dfn{development environments} containing all the dependencies and tools
4359 necessary to work on the software package of your choice. The @command{guix
4360 pack} command allows you to create @dfn{application bundles} that can be
4361 easily distributed to users who do not run Guix.
4364 * Invoking guix environment:: Setting up development environments.
4365 * Invoking guix pack:: Creating software bundles.
4368 @node Invoking guix environment
4369 @section Invoking @command{guix environment}
4371 @cindex reproducible build environments
4372 @cindex development environments
4373 @cindex @command{guix environment}
4374 @cindex environment, package build environment
4375 The purpose of @command{guix environment} is to assist hackers in
4376 creating reproducible development environments without polluting their
4377 package profile. The @command{guix environment} tool takes one or more
4378 packages, builds all of their inputs, and creates a shell
4379 environment to use them.
4381 The general syntax is:
4384 guix environment @var{options} @var{package}@dots{}
4387 The following example spawns a new shell set up for the development of
4391 guix environment guile
4394 If the needed dependencies are not built yet, @command{guix environment}
4395 automatically builds them. The environment of the new shell is an augmented
4396 version of the environment that @command{guix environment} was run in.
4397 It contains the necessary search paths for building the given package
4398 added to the existing environment variables. To create a ``pure''
4399 environment, in which the original environment variables have been unset,
4400 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4401 environment variables such as @code{PATH} in their @file{~/.bashrc}
4402 file. As a consequence, when @code{guix environment} launches it, Bash
4403 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4404 environment variables. It is an error to define such environment
4405 variables in @file{.bashrc}; instead, they should be defined in
4406 @file{.bash_profile}, which is sourced only by log-in shells.
4407 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4408 details on Bash start-up files.}.
4410 @vindex GUIX_ENVIRONMENT
4411 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4412 variable in the shell it spawns; its value is the file name of the
4413 profile of this environment. This allows users to, say, define a
4414 specific prompt for development environments in their @file{.bashrc}
4415 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4418 if [ -n "$GUIX_ENVIRONMENT" ]
4420 export PS1="\u@@\h \w [dev]\$ "
4425 ...@: or to browse the profile:
4428 $ ls "$GUIX_ENVIRONMENT/bin"
4431 Additionally, more than one package may be specified, in which case the
4432 union of the inputs for the given packages are used. For example, the
4433 command below spawns a shell where all of the dependencies of both Guile
4434 and Emacs are available:
4437 guix environment guile emacs
4440 Sometimes an interactive shell session is not desired. An arbitrary
4441 command may be invoked by placing the @code{--} token to separate the
4442 command from the rest of the arguments:
4445 guix environment guile -- make -j4
4448 In other situations, it is more convenient to specify the list of
4449 packages needed in the environment. For example, the following command
4450 runs @command{python} from an environment containing Python@tie{}2.7 and
4454 guix environment --ad-hoc python2-numpy python-2.7 -- python
4457 Furthermore, one might want the dependencies of a package and also some
4458 additional packages that are not build-time or runtime dependencies, but
4459 are useful when developing nonetheless. Because of this, the
4460 @code{--ad-hoc} flag is positional. Packages appearing before
4461 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4462 added to the environment. Packages appearing after are interpreted as
4463 packages that will be added to the environment directly. For example,
4464 the following command creates a Guix development environment that
4465 additionally includes Git and strace:
4468 guix environment guix --ad-hoc git strace
4471 Sometimes it is desirable to isolate the environment as much as
4472 possible, for maximal purity and reproducibility. In particular, when
4473 using Guix on a host distro that is not Guix System, it is desirable to
4474 prevent access to @file{/usr/bin} and other system-wide resources from
4475 the development environment. For example, the following command spawns
4476 a Guile REPL in a ``container'' where only the store and the current
4477 working directory are mounted:
4480 guix environment --ad-hoc --container guile -- guile
4484 The @code{--container} option requires Linux-libre 3.19 or newer.
4487 The available options are summarized below.
4490 @item --root=@var{file}
4491 @itemx -r @var{file}
4492 @cindex persistent environment
4493 @cindex garbage collector root, for environments
4494 Make @var{file} a symlink to the profile for this environment, and
4495 register it as a garbage collector root.
4497 This is useful if you want to protect your environment from garbage
4498 collection, to make it ``persistent''.
4500 When this option is omitted, the environment is protected from garbage
4501 collection only for the duration of the @command{guix environment}
4502 session. This means that next time you recreate the same environment,
4503 you could have to rebuild or re-download packages. @xref{Invoking guix
4504 gc}, for more on GC roots.
4506 @item --expression=@var{expr}
4507 @itemx -e @var{expr}
4508 Create an environment for the package or list of packages that
4509 @var{expr} evaluates to.
4511 For example, running:
4514 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4517 starts a shell with the environment for this specific variant of the
4523 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4526 starts a shell with all the base system packages available.
4528 The above commands only use the default output of the given packages.
4529 To select other outputs, two element tuples can be specified:
4532 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4535 @item --load=@var{file}
4536 @itemx -l @var{file}
4537 Create an environment for the package or list of packages that the code
4538 within @var{file} evaluates to.
4540 As an example, @var{file} might contain a definition like this
4541 (@pxref{Defining Packages}):
4544 @verbatiminclude environment-gdb.scm
4547 @item --manifest=@var{file}
4548 @itemx -m @var{file}
4549 Create an environment for the packages contained in the manifest object
4550 returned by the Scheme code in @var{file}.
4552 This is similar to the same-named option in @command{guix package}
4553 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4557 Include all specified packages in the resulting environment, as if an
4558 @i{ad hoc} package were defined with them as inputs. This option is
4559 useful for quickly creating an environment without having to write a
4560 package expression to contain the desired inputs.
4562 For instance, the command:
4565 guix environment --ad-hoc guile guile-sdl -- guile
4568 runs @command{guile} in an environment where Guile and Guile-SDL are
4571 Note that this example implicitly asks for the default output of
4572 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4573 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4574 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4576 This option may be composed with the default behavior of @command{guix
4577 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4578 as packages whose dependencies will be added to the environment, the
4579 default behavior. Packages appearing after are interpreted as packages
4580 that will be added to the environment directly.
4583 Unset existing environment variables when building the new environment, except
4584 those specified with @option{--preserve} (see below.) This has the effect of
4585 creating an environment in which search paths only contain package inputs.
4587 @item --preserve=@var{regexp}
4588 @itemx -E @var{regexp}
4589 When used alongside @option{--pure}, preserve the environment variables
4590 matching @var{regexp}---in other words, put them on a ``white list'' of
4591 environment variables that must be preserved. This option can be repeated
4595 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4599 This example runs @command{mpirun} in a context where the only environment
4600 variables defined are @code{PATH}, environment variables whose name starts
4601 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4604 @item --search-paths
4605 Display the environment variable definitions that make up the
4608 @item --system=@var{system}
4609 @itemx -s @var{system}
4610 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4615 Run @var{command} within an isolated container. The current working
4616 directory outside the container is mapped inside the container.
4617 Additionally, unless overridden with @code{--user}, a dummy home
4618 directory is created that matches the current user's home directory, and
4619 @file{/etc/passwd} is configured accordingly.
4621 The spawned process runs as the current user outside the container. Inside
4622 the container, it has the same UID and GID as the current user, unless
4623 @option{--user} is passed (see below.)
4627 For containers, share the network namespace with the host system.
4628 Containers created without this flag only have access to the loopback
4631 @item --link-profile
4633 For containers, link the environment profile to
4634 @file{~/.guix-profile} within the container. This is equivalent to
4635 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4636 within the container. Linking will fail and abort the environment if
4637 the directory already exists, which will certainly be the case if
4638 @command{guix environment} was invoked in the user's home directory.
4640 Certain packages are configured to look in
4641 @code{~/.guix-profile} for configuration files and data;@footnote{For
4642 example, the @code{fontconfig} package inspects
4643 @file{~/.guix-profile/share/fonts} for additional fonts.}
4644 @code{--link-profile} allows these programs to behave as expected within
4647 @item --user=@var{user}
4648 @itemx -u @var{user}
4649 For containers, use the username @var{user} in place of the current
4650 user. The generated @file{/etc/passwd} entry within the container will
4651 contain the name @var{user}, the home directory will be
4652 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4653 the UID and GID inside the container are 1000. @var{user}
4654 need not exist on the system.
4656 Additionally, any shared or exposed path (see @code{--share} and
4657 @code{--expose} respectively) whose target is within the current user's
4658 home directory will be remapped relative to @file{/home/USER}; this
4659 includes the automatic mapping of the current working directory.
4662 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4664 guix environment --container --user=foo \
4665 --expose=$HOME/test \
4666 --expose=/tmp/target=$HOME/target
4669 While this will limit the leaking of user identity through home paths
4670 and each of the user fields, this is only one useful component of a
4671 broader privacy/anonymity solution---not one in and of itself.
4674 For containers, the default behavior is to share the current working
4675 directory with the isolated container and immediately change to that
4676 directory within the container. If this is undesirable, @code{--no-cwd}
4677 will cause the current working directory to @emph{not} be automatically
4678 shared and will change to the user's home directory within the container
4679 instead. See also @code{--user}.
4681 @item --expose=@var{source}[=@var{target}]
4682 For containers, expose the file system @var{source} from the host system
4683 as the read-only file system @var{target} within the container. If
4684 @var{target} is not specified, @var{source} is used as the target mount
4685 point in the container.
4687 The example below spawns a Guile REPL in a container in which the user's
4688 home directory is accessible read-only via the @file{/exchange}
4692 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4695 @item --share=@var{source}[=@var{target}]
4696 For containers, share the file system @var{source} from the host system
4697 as the writable file system @var{target} within the container. If
4698 @var{target} is not specified, @var{source} is used as the target mount
4699 point in the container.
4701 The example below spawns a Guile REPL in a container in which the user's
4702 home directory is accessible for both reading and writing via the
4703 @file{/exchange} directory:
4706 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4710 @command{guix environment}
4711 also supports all of the common build options that @command{guix
4712 build} supports (@pxref{Common Build Options}) as well as package
4713 transformation options (@pxref{Package Transformation Options}).
4715 @node Invoking guix pack
4716 @section Invoking @command{guix pack}
4718 Occasionally you want to pass software to people who are not (yet!)
4719 lucky enough to be using Guix. You'd tell them to run @command{guix
4720 package -i @var{something}}, but that's not possible in this case. This
4721 is where @command{guix pack} comes in.
4724 If you are looking for ways to exchange binaries among machines that
4725 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4726 publish}, and @ref{Invoking guix archive}.
4731 @cindex application bundle
4732 @cindex software bundle
4733 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4734 @dfn{software bundle}: it creates a tarball or some other archive
4735 containing the binaries of the software you're interested in, and all
4736 its dependencies. The resulting archive can be used on any machine that
4737 does not have Guix, and people can run the exact same binaries as those
4738 you have with Guix. The pack itself is created in a bit-reproducible
4739 fashion, so anyone can verify that it really contains the build results
4740 that you pretend to be shipping.
4742 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4743 their dependencies, you can run:
4746 $ guix pack guile emacs geiser
4748 /gnu/store/@dots{}-pack.tar.gz
4751 The result here is a tarball containing a @file{/gnu/store} directory
4752 with all the relevant packages. The resulting tarball contains a
4753 @dfn{profile} with the three packages of interest; the profile is the
4754 same as would be created by @command{guix package -i}. It is this
4755 mechanism that is used to create Guix's own standalone binary tarball
4756 (@pxref{Binary Installation}).
4758 Users of this pack would have to run
4759 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4760 find inconvenient. To work around it, you can create, say, a
4761 @file{/opt/gnu/bin} symlink to the profile:
4764 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4768 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4770 @cindex relocatable binaries, with @command{guix pack}
4771 What if the recipient of your pack does not have root privileges on
4772 their machine, and thus cannot unpack it in the root file system? In
4773 that case, you will want to use the @code{--relocatable} option (see
4774 below). This option produces @dfn{relocatable binaries}, meaning they
4775 they can be placed anywhere in the file system hierarchy: in the example
4776 above, users can unpack your tarball in their home directory and
4777 directly run @file{./opt/gnu/bin/guile}.
4779 @cindex Docker, build an image with guix pack
4780 Alternatively, you can produce a pack in the Docker image format using
4781 the following command:
4784 guix pack -f docker guile emacs geiser
4788 The result is a tarball that can be passed to the @command{docker load}
4790 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4791 documentation} for more information.
4793 @cindex Singularity, build an image with guix pack
4794 @cindex SquashFS, build an image with guix pack
4795 Yet another option is to produce a SquashFS image with the following
4799 guix pack -f squashfs guile emacs geiser
4803 The result is a SquashFS file system image that can either be mounted or
4804 directly be used as a file system container image with the
4805 @uref{https://singularity.lbl.gov, Singularity container execution
4806 environment}, using commands like @command{singularity shell} or
4807 @command{singularity exec}.
4809 Several command-line options allow you to customize your pack:
4812 @item --format=@var{format}
4813 @itemx -f @var{format}
4814 Produce a pack in the given @var{format}.
4816 The available formats are:
4820 This is the default format. It produces a tarball containing all the
4821 specified binaries and symlinks.
4824 This produces a tarball that follows the
4825 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4826 Docker Image Specification}.
4829 This produces a SquashFS image containing all the specified binaries and
4830 symlinks, as well as empty mount points for virtual file systems like
4834 @cindex relocatable binaries
4837 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4838 anywhere in the file system hierarchy and run from there.
4840 When this option is passed once, the resulting binaries require support for
4841 @dfn{user namespaces} in the kernel Linux; when passed
4842 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4843 PRoot support, can be thought of as the abbreviation of ``Really
4844 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4845 if user namespaces are unavailable, and essentially work anywhere---see below
4846 for the implications.
4848 For example, if you create a pack containing Bash with:
4851 guix pack -RR -S /mybin=bin bash
4855 ...@: you can copy that pack to a machine that lacks Guix, and from your
4856 home directory as a normal user, run:
4864 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4865 @file{/gnu/store} shows up and contains all the dependencies of
4866 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4867 altogether! That is probably the simplest way to deploy Guix-built
4868 software on a non-Guix machine.
4871 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4872 the kernel Linux, which allows unprivileged users to mount or change root.
4873 Old versions of Linux did not support it, and some GNU/Linux distributions
4876 To produce relocatable binaries that work even in the absence of user
4877 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4878 case, binaries will try user namespace support and fall back to PRoot if user
4879 namespaces are not supported.
4881 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4882 support for file system virtualization. It achieves that by using the
4883 @code{ptrace} system call on the running program. This approach has the
4884 advantage to work without requiring special kernel support, but it incurs
4885 run-time overhead every time a system call is made.
4888 @cindex entry point, for Docker images
4889 @item --entry-point=@var{command}
4890 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
4891 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
4892 support it. @var{command} must be relative to the profile contained in the
4895 The entry point specifies the command that tools like @code{docker run} or
4896 @code{singularity run} automatically start by default. For example, you can
4900 guix pack -f docker --entry-point=bin/guile guile
4903 The resulting pack can easily be loaded and @code{docker run} with no extra
4904 arguments will spawn @code{bin/guile}:
4907 docker load -i pack.tar.gz
4908 docker run @var{image-id}
4911 @item --expression=@var{expr}
4912 @itemx -e @var{expr}
4913 Consider the package @var{expr} evaluates to.
4915 This has the same purpose as the same-named option in @command{guix
4916 build} (@pxref{Additional Build Options, @code{--expression} in
4917 @command{guix build}}).
4919 @item --manifest=@var{file}
4920 @itemx -m @var{file}
4921 Use the packages contained in the manifest object returned by the Scheme
4924 This has a similar purpose as the same-named option in @command{guix
4925 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4926 same manifest files. It allows you to define a collection of packages
4927 once and use it both for creating profiles and for creating archives
4928 for use on machines that do not have Guix installed. Note that you can
4929 specify @emph{either} a manifest file @emph{or} a list of packages,
4932 @item --system=@var{system}
4933 @itemx -s @var{system}
4934 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4935 the system type of the build host.
4937 @item --target=@var{triplet}
4938 @cindex cross-compilation
4939 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4940 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4941 configuration triplets,, autoconf, Autoconf}).
4943 @item --compression=@var{tool}
4944 @itemx -C @var{tool}
4945 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4946 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4948 @item --symlink=@var{spec}
4949 @itemx -S @var{spec}
4950 Add the symlinks specified by @var{spec} to the pack. This option can
4951 appear several times.
4953 @var{spec} has the form @code{@var{source}=@var{target}}, where
4954 @var{source} is the symlink that will be created and @var{target} is the
4957 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4958 symlink pointing to the @file{bin} sub-directory of the profile.
4960 @item --save-provenance
4961 Save provenance information for the packages passed on the command line.
4962 Provenance information includes the URL and commit of the channels in use
4965 Provenance information is saved in the
4966 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4967 usual package metadata---the name and version of each package, their
4968 propagated inputs, and so on. It is useful information to the recipient of
4969 the pack, who then knows how the pack was (supposedly) obtained.
4971 This option is not enabled by default because, like timestamps, provenance
4972 information contributes nothing to the build process. In other words, there
4973 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4974 Recording such ``silent'' metadata in the output thus potentially breaks the
4975 source-to-binary bitwise reproducibility property.
4977 @item --root=@var{file}
4978 @itemx -r @var{file}
4979 @cindex garbage collector root, for packs
4980 Make @var{file} a symlink to the resulting pack, and register it as a garbage
4983 @item --localstatedir
4984 @itemx --profile-name=@var{name}
4985 Include the ``local state directory'', @file{/var/guix}, in the resulting
4986 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4987 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4988 @file{~root/.guix-profile}.
4990 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4991 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4992 the pack means that the store is ``complete'' and manageable by Guix;
4993 not providing it pack means that the store is ``dead'': items cannot be
4994 added to it or removed from it after extraction of the pack.
4996 One use case for this is the Guix self-contained binary tarball
4997 (@pxref{Binary Installation}).
5000 Use the bootstrap binaries to build the pack. This option is only
5001 useful to Guix developers.
5004 In addition, @command{guix pack} supports all the common build options
5005 (@pxref{Common Build Options}) and all the package transformation
5006 options (@pxref{Package Transformation Options}).
5009 @c *********************************************************************
5010 @node Programming Interface
5011 @chapter Programming Interface
5013 GNU Guix provides several Scheme programming interfaces (APIs) to
5014 define, build, and query packages. The first interface allows users to
5015 write high-level package definitions. These definitions refer to
5016 familiar packaging concepts, such as the name and version of a package,
5017 its build system, and its dependencies. These definitions can then be
5018 turned into concrete build actions.
5020 Build actions are performed by the Guix daemon, on behalf of users. In a
5021 standard setup, the daemon has write access to the store---the
5022 @file{/gnu/store} directory---whereas users do not. The recommended
5023 setup also has the daemon perform builds in chroots, under a specific
5024 build users, to minimize interference with the rest of the system.
5027 Lower-level APIs are available to interact with the daemon and the
5028 store. To instruct the daemon to perform a build action, users actually
5029 provide it with a @dfn{derivation}. A derivation is a low-level
5030 representation of the build actions to be taken, and the environment in
5031 which they should occur---derivations are to package definitions what
5032 assembly is to C programs. The term ``derivation'' comes from the fact
5033 that build results @emph{derive} from them.
5035 This chapter describes all these APIs in turn, starting from high-level
5036 package definitions.
5039 * Package Modules:: Packages from the programmer's viewpoint.
5040 * Defining Packages:: Defining new packages.
5041 * Build Systems:: Specifying how packages are built.
5042 * The Store:: Manipulating the package store.
5043 * Derivations:: Low-level interface to package derivations.
5044 * The Store Monad:: Purely functional interface to the store.
5045 * G-Expressions:: Manipulating build expressions.
5046 * Invoking guix repl:: Fiddling with Guix interactively.
5049 @node Package Modules
5050 @section Package Modules
5052 From a programming viewpoint, the package definitions of the
5053 GNU distribution are provided by Guile modules in the @code{(gnu packages
5054 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5055 packages @dots{})} module name space are not necessarily ``GNU
5056 packages''. This module naming scheme follows the usual Guile module
5057 naming convention: @code{gnu} means that these modules are distributed
5058 as part of the GNU system, and @code{packages} identifies modules that
5059 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5060 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5061 module exports a variable named @code{emacs}, which is bound to a
5062 @code{<package>} object (@pxref{Defining Packages}).
5064 The @code{(gnu packages @dots{})} module name space is
5065 automatically scanned for packages by the command-line tools. For
5066 instance, when running @code{guix install emacs}, all the @code{(gnu
5067 packages @dots{})} modules are scanned until one that exports a package
5068 object whose name is @code{emacs} is found. This package search
5069 facility is implemented in the @code{(gnu packages)} module.
5071 @cindex customization, of packages
5072 @cindex package module search path
5073 Users can store package definitions in modules with different
5074 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5075 name and module name must match. For instance, the @code{(my-packages
5076 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5077 relative to the load path specified with @option{--load-path} or
5078 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5079 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5080 these package definitions visible to the user interfaces:
5084 By adding the directory containing your package modules to the search path
5085 with the @code{-L} flag of @command{guix package} and other commands
5086 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5087 environment variable described below.
5090 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5091 pulls from it. A channel is essentially a Git repository containing package
5092 modules. @xref{Channels}, for more information on how to define and use
5096 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5098 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5099 This is a colon-separated list of directories to search for additional
5100 package modules. Directories listed in this variable take precedence
5101 over the own modules of the distribution.
5104 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5105 each package is built based solely on other packages in the
5106 distribution. The root of this dependency graph is a small set of
5107 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5108 bootstrap)} module. For more information on bootstrapping,
5109 @pxref{Bootstrapping}.
5111 @node Defining Packages
5112 @section Defining Packages
5114 The high-level interface to package definitions is implemented in the
5115 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5116 example, the package definition, or @dfn{recipe}, for the GNU Hello
5117 package looks like this:
5120 (define-module (gnu packages hello)
5121 #:use-module (guix packages)
5122 #:use-module (guix download)
5123 #:use-module (guix build-system gnu)
5124 #:use-module (guix licenses)
5125 #:use-module (gnu packages gawk))
5127 (define-public hello
5133 (uri (string-append "mirror://gnu/hello/hello-" version
5137 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5138 (build-system gnu-build-system)
5139 (arguments '(#:configure-flags '("--enable-silent-rules")))
5140 (inputs `(("gawk" ,gawk)))
5141 (synopsis "Hello, GNU world: An example GNU package")
5142 (description "Guess what GNU Hello prints!")
5143 (home-page "https://www.gnu.org/software/hello/")
5148 Without being a Scheme expert, the reader may have guessed the meaning
5149 of the various fields here. This expression binds the variable
5150 @code{hello} to a @code{<package>} object, which is essentially a record
5151 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5152 This package object can be inspected using procedures found in the
5153 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5154 returns---surprise!---@code{"hello"}.
5156 With luck, you may be able to import part or all of the definition of
5157 the package you are interested in from another repository, using the
5158 @code{guix import} command (@pxref{Invoking guix import}).
5160 In the example above, @var{hello} is defined in a module of its own,
5161 @code{(gnu packages hello)}. Technically, this is not strictly
5162 necessary, but it is convenient to do so: all the packages defined in
5163 modules under @code{(gnu packages @dots{})} are automatically known to
5164 the command-line tools (@pxref{Package Modules}).
5166 There are a few points worth noting in the above package definition:
5170 The @code{source} field of the package is an @code{<origin>} object
5171 (@pxref{origin Reference}, for the complete reference).
5172 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5173 meaning that the source is a file to be downloaded over FTP or HTTP.
5175 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5176 the GNU mirrors defined in @code{(guix download)}.
5178 The @code{sha256} field specifies the expected SHA256 hash of the file
5179 being downloaded. It is mandatory, and allows Guix to check the
5180 integrity of the file. The @code{(base32 @dots{})} form introduces the
5181 base32 representation of the hash. You can obtain this information with
5182 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5183 hash} (@pxref{Invoking guix hash}).
5186 When needed, the @code{origin} form can also have a @code{patches} field
5187 listing patches to be applied, and a @code{snippet} field giving a
5188 Scheme expression to modify the source code.
5191 @cindex GNU Build System
5192 The @code{build-system} field specifies the procedure to build the
5193 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5194 represents the familiar GNU Build System, where packages may be
5195 configured, built, and installed with the usual @code{./configure &&
5196 make && make check && make install} command sequence.
5199 The @code{arguments} field specifies options for the build system
5200 (@pxref{Build Systems}). Here it is interpreted by
5201 @var{gnu-build-system} as a request run @file{configure} with the
5202 @code{--enable-silent-rules} flag.
5208 What about these quote (@code{'}) characters? They are Scheme syntax to
5209 introduce a literal list; @code{'} is synonymous with @code{quote}.
5210 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5211 for details. Here the value of the @code{arguments} field is a list of
5212 arguments passed to the build system down the road, as with @code{apply}
5213 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5216 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5217 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5218 @code{#:configure-flags} is a keyword used to pass a keyword argument
5219 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5223 The @code{inputs} field specifies inputs to the build process---i.e.,
5224 build-time or run-time dependencies of the package. Here, we define an
5225 input called @code{"gawk"} whose value is that of the @var{gawk}
5226 variable; @var{gawk} is itself bound to a @code{<package>} object.
5228 @cindex backquote (quasiquote)
5231 @cindex comma (unquote)
5235 @findex unquote-splicing
5236 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5237 us to introduce a literal list in the @code{inputs} field, while
5238 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5239 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5242 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5243 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5244 of ensuring that they are present (@pxref{Build Systems}).
5246 However, any other dependencies need to be specified in the
5247 @code{inputs} field. Any dependency not specified here will simply be
5248 unavailable to the build process, possibly leading to a build failure.
5251 @xref{package Reference}, for a full description of possible fields.
5253 Once a package definition is in place, the
5254 package may actually be built using the @code{guix build} command-line
5255 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5256 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5257 package definition using the @command{guix edit} command
5258 (@pxref{Invoking guix edit}).
5259 @xref{Packaging Guidelines}, for
5260 more information on how to test package definitions, and
5261 @ref{Invoking guix lint}, for information on how to check a definition
5262 for style conformance.
5263 @vindex GUIX_PACKAGE_PATH
5264 Lastly, @pxref{Channels}, for information
5265 on how to extend the distribution by adding your own package definitions
5268 Finally, updating the package definition to a new upstream version
5269 can be partly automated by the @command{guix refresh} command
5270 (@pxref{Invoking guix refresh}).
5272 Behind the scenes, a derivation corresponding to the @code{<package>}
5273 object is first computed by the @code{package-derivation} procedure.
5274 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5275 The build actions it prescribes may then be realized by using the
5276 @code{build-derivations} procedure (@pxref{The Store}).
5278 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5279 Return the @code{<derivation>} object of @var{package} for @var{system}
5280 (@pxref{Derivations}).
5282 @var{package} must be a valid @code{<package>} object, and @var{system}
5283 must be a string denoting the target system type---e.g.,
5284 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5285 must be a connection to the daemon, which operates on the store
5286 (@pxref{The Store}).
5290 @cindex cross-compilation
5291 Similarly, it is possible to compute a derivation that cross-builds a
5292 package for some other system:
5294 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5295 @var{package} @var{target} [@var{system}]
5296 Return the @code{<derivation>} object of @var{package} cross-built from
5297 @var{system} to @var{target}.
5299 @var{target} must be a valid GNU triplet denoting the target hardware
5300 and operating system, such as @code{"mips64el-linux-gnu"}
5301 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5304 @cindex package transformations
5305 @cindex input rewriting
5306 @cindex dependency tree rewriting
5307 Packages can be manipulated in arbitrary ways. An example of a useful
5308 transformation is @dfn{input rewriting}, whereby the dependency tree of
5309 a package is rewritten by replacing specific inputs by others:
5311 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5312 [@var{rewrite-name}]
5313 Return a procedure that, when passed a package, replaces its direct and
5314 indirect dependencies (but not its implicit inputs) according to
5315 @var{replacements}. @var{replacements} is a list of package pairs; the
5316 first element of each pair is the package to replace, and the second one
5319 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5320 the name of a package and returns its new name after rewrite.
5324 Consider this example:
5327 (define libressl-instead-of-openssl
5328 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5330 (package-input-rewriting `((,openssl . ,libressl))))
5332 (define git-with-libressl
5333 (libressl-instead-of-openssl git))
5337 Here we first define a rewriting procedure that replaces @var{openssl}
5338 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5339 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5340 This is exactly what the @option{--with-input} command-line option does
5341 (@pxref{Package Transformation Options, @option{--with-input}}).
5343 The following variant of @code{package-input-rewriting} can match packages to
5344 be replaced by name rather than by identity.
5346 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5347 Return a procedure that, given a package, applies the given @var{replacements} to
5348 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5349 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5350 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5351 replacement for that package.
5354 The example above could be rewritten this way:
5357 (define libressl-instead-of-openssl
5358 ;; Replace all the packages called "openssl" with LibreSSL.
5359 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5362 The key difference here is that, this time, packages are matched by spec and
5363 not by identity. In other words, any package in the graph that is called
5364 @code{openssl} will be replaced.
5366 A more generic procedure to rewrite a package dependency graph is
5367 @code{package-mapping}: it supports arbitrary changes to nodes in the
5370 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5371 Return a procedure that, given a package, applies @var{proc} to all the packages
5372 depended on and returns the resulting package. The procedure stops recursion
5373 when @var{cut?} returns true for a given package.
5377 * package Reference:: The package data type.
5378 * origin Reference:: The origin data type.
5382 @node package Reference
5383 @subsection @code{package} Reference
5385 This section summarizes all the options available in @code{package}
5386 declarations (@pxref{Defining Packages}).
5388 @deftp {Data Type} package
5389 This is the data type representing a package recipe.
5393 The name of the package, as a string.
5395 @item @code{version}
5396 The version of the package, as a string.
5399 An object telling how the source code for the package should be
5400 acquired. Most of the time, this is an @code{origin} object, which
5401 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5402 can also be any other ``file-like'' object such as a @code{local-file},
5403 which denotes a file from the local file system (@pxref{G-Expressions,
5404 @code{local-file}}).
5406 @item @code{build-system}
5407 The build system that should be used to build the package (@pxref{Build
5410 @item @code{arguments} (default: @code{'()})
5411 The arguments that should be passed to the build system. This is a
5412 list, typically containing sequential keyword-value pairs.
5414 @item @code{inputs} (default: @code{'()})
5415 @itemx @code{native-inputs} (default: @code{'()})
5416 @itemx @code{propagated-inputs} (default: @code{'()})
5417 @cindex inputs, of packages
5418 These fields list dependencies of the package. Each one is a list of
5419 tuples, where each tuple has a label for the input (a string) as its
5420 first element, a package, origin, or derivation as its second element,
5421 and optionally the name of the output thereof that should be used, which
5422 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5423 more on package outputs). For example, the list below specifies three
5427 `(("libffi" ,libffi)
5428 ("libunistring" ,libunistring)
5429 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5432 @cindex cross compilation, package dependencies
5433 The distinction between @code{native-inputs} and @code{inputs} is
5434 necessary when considering cross-compilation. When cross-compiling,
5435 dependencies listed in @code{inputs} are built for the @emph{target}
5436 architecture; conversely, dependencies listed in @code{native-inputs}
5437 are built for the architecture of the @emph{build} machine.
5439 @code{native-inputs} is typically used to list tools needed at
5440 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5441 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5442 this area (@pxref{Invoking guix lint}).
5444 @anchor{package-propagated-inputs}
5445 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5446 specified packages will be automatically installed alongside the package
5447 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5448 package}}, for information on how @command{guix package} deals with
5451 For example this is necessary when a C/C++ library needs headers of
5452 another library to compile, or when a pkg-config file refers to another
5453 one @i{via} its @code{Requires} field.
5455 Another example where @code{propagated-inputs} is useful is for languages
5456 that lack a facility to record the run-time search path akin to the
5457 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5458 more. To ensure that libraries written in those languages can find
5459 library code they depend on at run time, run-time dependencies must be
5460 listed in @code{propagated-inputs} rather than @code{inputs}.
5462 @item @code{outputs} (default: @code{'("out")})
5463 The list of output names of the package. @xref{Packages with Multiple
5464 Outputs}, for typical uses of additional outputs.
5466 @item @code{native-search-paths} (default: @code{'()})
5467 @itemx @code{search-paths} (default: @code{'()})
5468 A list of @code{search-path-specification} objects describing
5469 search-path environment variables honored by the package.
5471 @item @code{replacement} (default: @code{#f})
5472 This must be either @code{#f} or a package object that will be used as a
5473 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5476 @item @code{synopsis}
5477 A one-line description of the package.
5479 @item @code{description}
5480 A more elaborate description of the package.
5482 @item @code{license}
5483 @cindex license, of packages
5484 The license of the package; a value from @code{(guix licenses)},
5485 or a list of such values.
5487 @item @code{home-page}
5488 The URL to the home-page of the package, as a string.
5490 @item @code{supported-systems} (default: @var{%supported-systems})
5491 The list of systems supported by the package, as strings of the form
5492 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5494 @item @code{maintainers} (default: @code{'()})
5495 The list of maintainers of the package, as @code{maintainer} objects.
5497 @item @code{location} (default: source location of the @code{package} form)
5498 The source location of the package. It is useful to override this when
5499 inheriting from another package, in which case this field is not
5500 automatically corrected.
5504 @deffn {Scheme Syntax} this-package
5505 When used in the @emph{lexical scope} of a package field definition, this
5506 identifier resolves to the package being defined.
5508 The example below shows how to add a package as a native input of itself when
5516 ;; When cross-compiled, Guile, for example, depends on
5517 ;; a native version of itself. Add it here.
5518 (native-inputs (if (%current-target-system)
5519 `(("self" ,this-package))
5523 It is an error to refer to @code{this-package} outside a package definition.
5526 @node origin Reference
5527 @subsection @code{origin} Reference
5529 This section summarizes all the options available in @code{origin}
5530 declarations (@pxref{Defining Packages}).
5532 @deftp {Data Type} origin
5533 This is the data type representing a source code origin.
5537 An object containing the URI of the source. The object type depends on
5538 the @code{method} (see below). For example, when using the
5539 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5540 values are: a URL represented as a string, or a list thereof.
5543 A procedure that handles the URI.
5548 @item @var{url-fetch} from @code{(guix download)}
5549 download a file from the HTTP, HTTPS, or FTP URL specified in the
5553 @item @var{git-fetch} from @code{(guix git-download)}
5554 clone the Git version control repository, and check out the revision
5555 specified in the @code{uri} field as a @code{git-reference} object; a
5556 @code{git-reference} looks like this:
5560 (url "git://git.debian.org/git/pkg-shadow/shadow")
5561 (commit "v4.1.5.1"))
5566 A bytevector containing the SHA-256 hash of the source. Typically the
5567 @code{base32} form is used here to generate the bytevector from a
5570 You can obtain this information using @code{guix download}
5571 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5574 @item @code{file-name} (default: @code{#f})
5575 The file name under which the source code should be saved. When this is
5576 @code{#f}, a sensible default value will be used in most cases. In case
5577 the source is fetched from a URL, the file name from the URL will be
5578 used. For version control checkouts, it is recommended to provide the
5579 file name explicitly because the default is not very descriptive.
5581 @item @code{patches} (default: @code{'()})
5582 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5583 file-like objects}) pointing to patches to be applied to the source.
5585 This list of patches must be unconditional. In particular, it cannot
5586 depend on the value of @code{%current-system} or
5587 @code{%current-target-system}.
5589 @item @code{snippet} (default: @code{#f})
5590 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5591 in the source directory. This is a convenient way to modify the source,
5592 sometimes more convenient than a patch.
5594 @item @code{patch-flags} (default: @code{'("-p1")})
5595 A list of command-line flags that should be passed to the @code{patch}
5598 @item @code{patch-inputs} (default: @code{#f})
5599 Input packages or derivations to the patching process. When this is
5600 @code{#f}, the usual set of inputs necessary for patching are provided,
5601 such as GNU@tie{}Patch.
5603 @item @code{modules} (default: @code{'()})
5604 A list of Guile modules that should be loaded during the patching
5605 process and while running the code in the @code{snippet} field.
5607 @item @code{patch-guile} (default: @code{#f})
5608 The Guile package that should be used in the patching process. When
5609 this is @code{#f}, a sensible default is used.
5615 @section Build Systems
5617 @cindex build system
5618 Each package definition specifies a @dfn{build system} and arguments for
5619 that build system (@pxref{Defining Packages}). This @code{build-system}
5620 field represents the build procedure of the package, as well as implicit
5621 dependencies of that build procedure.
5623 Build systems are @code{<build-system>} objects. The interface to
5624 create and manipulate them is provided by the @code{(guix build-system)}
5625 module, and actual build systems are exported by specific modules.
5627 @cindex bag (low-level package representation)
5628 Under the hood, build systems first compile package objects to
5629 @dfn{bags}. A @dfn{bag} is like a package, but with less
5630 ornamentation---in other words, a bag is a lower-level representation of
5631 a package, which includes all the inputs of that package, including some
5632 that were implicitly added by the build system. This intermediate
5633 representation is then compiled to a derivation (@pxref{Derivations}).
5635 Build systems accept an optional list of @dfn{arguments}. In package
5636 definitions, these are passed @i{via} the @code{arguments} field
5637 (@pxref{Defining Packages}). They are typically keyword arguments
5638 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5639 Guile Reference Manual}). The value of these arguments is usually
5640 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5641 by the daemon (@pxref{Derivations}).
5643 The main build system is @var{gnu-build-system}, which implements the
5644 standard build procedure for GNU and many other packages. It
5645 is provided by the @code{(guix build-system gnu)} module.
5647 @defvr {Scheme Variable} gnu-build-system
5648 @var{gnu-build-system} represents the GNU Build System, and variants
5649 thereof (@pxref{Configuration, configuration and makefile conventions,,
5650 standards, GNU Coding Standards}).
5652 @cindex build phases
5653 In a nutshell, packages using it are configured, built, and installed with
5654 the usual @code{./configure && make && make check && make install}
5655 command sequence. In practice, a few additional steps are often needed.
5656 All these steps are split up in separate @dfn{phases},
5657 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5658 modules for more details about the build phases.}:
5662 Unpack the source tarball, and change the current directory to the
5663 extracted source tree. If the source is actually a directory, copy it
5664 to the build tree, and enter that directory.
5666 @item patch-source-shebangs
5667 Patch shebangs encountered in source files so they refer to the right
5668 store file names. For instance, this changes @code{#!/bin/sh} to
5669 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5672 Run the @file{configure} script with a number of default options, such
5673 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5674 by the @code{#:configure-flags} argument.
5677 Run @code{make} with the list of flags specified with
5678 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5679 (the default), build with @code{make -j}.
5682 Run @code{make check}, or some other target specified with
5683 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5684 @code{#:parallel-tests?} argument is true (the default), run @code{make
5688 Run @code{make install} with the flags listed in @code{#:make-flags}.
5690 @item patch-shebangs
5691 Patch shebangs on the installed executable files.
5694 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5695 is false), copying them to the @code{debug} output when available
5696 (@pxref{Installing Debugging Files}).
5699 @vindex %standard-phases
5700 The build-side module @code{(guix build gnu-build-system)} defines
5701 @var{%standard-phases} as the default list of build phases.
5702 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5703 procedure implements the actual phase.
5705 The list of phases used for a particular package can be changed with the
5706 @code{#:phases} parameter. For instance, passing:
5709 #:phases (modify-phases %standard-phases (delete 'configure))
5712 means that all the phases described above will be used, except the
5713 @code{configure} phase.
5715 In addition, this build system ensures that the ``standard'' environment
5716 for GNU packages is available. This includes tools such as GCC, libc,
5717 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5718 build-system gnu)} module for a complete list). We call these the
5719 @dfn{implicit inputs} of a package, because package definitions do not
5720 have to mention them.
5723 Other @code{<build-system>} objects are defined to support other
5724 conventions and tools used by free software packages. They inherit most
5725 of @var{gnu-build-system}, and differ mainly in the set of inputs
5726 implicitly added to the build process, and in the list of phases
5727 executed. Some of these build systems are listed below.
5729 @defvr {Scheme Variable} ant-build-system
5730 This variable is exported by @code{(guix build-system ant)}. It
5731 implements the build procedure for Java packages that can be built with
5732 @url{https://ant.apache.org/, Ant build tool}.
5734 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5735 provided by the @code{icedtea} package to the set of inputs. Different
5736 packages can be specified with the @code{#:ant} and @code{#:jdk}
5737 parameters, respectively.
5739 When the original package does not provide a suitable Ant build file,
5740 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5741 build file @file{build.xml} with tasks to build the specified jar
5742 archive. In this case the parameter @code{#:source-dir} can be used to
5743 specify the source sub-directory, defaulting to ``src''.
5745 The @code{#:main-class} parameter can be used with the minimal ant
5746 buildfile to specify the main class of the resulting jar. This makes the
5747 jar file executable. The @code{#:test-include} parameter can be used to
5748 specify the list of junit tests to run. It defaults to
5749 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5750 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5751 because abstract classes cannot be run as tests.
5753 The parameter @code{#:build-target} can be used to specify the Ant task
5754 that should be run during the @code{build} phase. By default the
5755 ``jar'' task will be run.
5759 @defvr {Scheme Variable} android-ndk-build-system
5760 @cindex Android distribution
5761 @cindex Android NDK build system
5762 This variable is exported by @code{(guix build-system android-ndk)}. It
5763 implements a build procedure for Android NDK (native development kit)
5764 packages using a Guix-specific build process.
5766 The build system assumes that packages install their public interface
5767 (header) files to the subdirectory "include" of the "out" output and
5768 their libraries to the subdirectory "lib" of the "out" output.
5770 It's also assumed that the union of all the dependencies of a package
5771 has no conflicting files.
5773 For the time being, cross-compilation is not supported - so right now
5774 the libraries and header files are assumed to be host tools.
5778 @defvr {Scheme Variable} asdf-build-system/source
5779 @defvrx {Scheme Variable} asdf-build-system/sbcl
5780 @defvrx {Scheme Variable} asdf-build-system/ecl
5782 These variables, exported by @code{(guix build-system asdf)}, implement
5783 build procedures for Common Lisp packages using
5784 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5785 definition facility for Common Lisp programs and libraries.
5787 The @code{asdf-build-system/source} system installs the packages in
5788 source form, and can be loaded using any common lisp implementation, via
5789 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5790 systems in the format which a particular implementation understands.
5791 These build systems can also be used to produce executable programs, or
5792 lisp images which contain a set of packages pre-loaded.
5794 The build system uses naming conventions. For binary packages, the
5795 package name should be prefixed with the lisp implementation, such as
5796 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5798 Additionally, the corresponding source package should be labeled using
5799 the same convention as python packages (see @ref{Python Modules}), using
5800 the @code{cl-} prefix.
5802 For binary packages, each system should be defined as a Guix package.
5803 If one package @code{origin} contains several systems, package variants
5804 can be created in order to build all the systems. Source packages,
5805 which use @code{asdf-build-system/source}, may contain several systems.
5807 In order to create executable programs and images, the build-side
5808 procedures @code{build-program} and @code{build-image} can be used.
5809 They should be called in a build phase after the @code{create-symlinks}
5810 phase, so that the system which was just built can be used within the
5811 resulting image. @code{build-program} requires a list of Common Lisp
5812 expressions to be passed as the @code{#:entry-program} argument.
5814 If the system is not defined within its own @code{.asd} file of the same
5815 name, then the @code{#:asd-file} parameter should be used to specify
5816 which file the system is defined in. Furthermore, if the package
5817 defines a system for its tests in a separate file, it will be loaded
5818 before the tests are run if it is specified by the
5819 @code{#:test-asd-file} parameter. If it is not set, the files
5820 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5821 and @code{test.asd} will be tried if they exist.
5823 If for some reason the package must be named in a different way than the
5824 naming conventions suggest, the @code{#:asd-system-name} parameter can
5825 be used to specify the name of the system.
5829 @defvr {Scheme Variable} cargo-build-system
5830 @cindex Rust programming language
5831 @cindex Cargo (Rust build system)
5832 This variable is exported by @code{(guix build-system cargo)}. It
5833 supports builds of packages using Cargo, the build tool of the
5834 @uref{https://www.rust-lang.org, Rust programming language}.
5836 It adds @code{rustc} and @code{cargo} to the set of inputs.
5837 A different Rust package can be specified with the @code{#:rust} parameter.
5839 Regular cargo dependencies should be added to the package definition via the
5840 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
5841 spec can be a package or a source definition. Note that the spec must
5842 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
5843 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
5844 should be added to the package definition via the
5845 @code{#:cargo-development-inputs} parameter.
5847 In its @code{configure} phase, this build system will make any source inputs
5848 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
5849 parameters available to cargo. The @code{install} phase installs any crate
5850 the binaries if they are defined by the crate.
5853 @cindex Clojure (programming language)
5854 @cindex simple Clojure build system
5855 @defvr {Scheme Variable} clojure-build-system
5856 This variable is exported by @code{(guix build-system clojure)}. It implements
5857 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5858 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5861 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5862 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5863 @code{#:zip} parameters, respectively.
5865 A list of source directories, test directories and jar names can be specified
5866 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5867 parameters, respectively. Compile directory and main class can be specified
5868 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5869 Other parameters are documented below.
5871 This build system is an extension of @var{ant-build-system}, but with the
5872 following phases changed:
5877 This phase calls @code{compile} in Clojure to compile source files and runs
5878 @command{jar} to create jars from both source files and compiled files
5879 according to the include list and exclude list specified in
5880 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5881 has priority over the include list. These lists consist of symbols
5882 representing Clojure libraries or the special keyword @code{#:all} representing
5883 all Clojure libraries found under the source directories. The parameter
5884 @code{#:omit-source?} decides if source should be included into the jars.
5887 This phase runs tests according to the include list and exclude list specified
5888 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5889 meanings are analogous to that of @code{#:aot-include} and
5890 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5891 stands for all Clojure libraries found under the test directories. The
5892 parameter @code{#:tests?} decides if tests should be run.
5895 This phase installs all jars built previously.
5898 Apart from the above, this build system also contains an additional phase:
5903 This phase installs all top-level files with base name matching
5904 @var{%doc-regex}. A different regex can be specified with the
5905 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5906 directories specified in @code{#:doc-dirs} are installed as well.
5910 @defvr {Scheme Variable} cmake-build-system
5911 This variable is exported by @code{(guix build-system cmake)}. It
5912 implements the build procedure for packages using the
5913 @url{https://www.cmake.org, CMake build tool}.
5915 It automatically adds the @code{cmake} package to the set of inputs.
5916 Which package is used can be specified with the @code{#:cmake}
5919 The @code{#:configure-flags} parameter is taken as a list of flags
5920 passed to the @command{cmake} command. The @code{#:build-type}
5921 parameter specifies in abstract terms the flags passed to the compiler;
5922 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5923 debugging information''), which roughly means that code is compiled with
5924 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5927 @defvr {Scheme Variable} dune-build-system
5928 This variable is exported by @code{(guix build-system dune)}. It
5929 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5930 tool for the OCaml programming language. It is implemented as an extension
5931 of the @code{ocaml-build-system} which is described below. As such, the
5932 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5935 It automatically adds the @code{dune} package to the set of inputs.
5936 Which package is used can be specified with the @code{#:dune}
5939 There is no @code{configure} phase because dune packages typically don't
5940 need to be configured. The @code{#:build-flags} parameter is taken as a
5941 list of flags passed to the @code{dune} command during the build.
5943 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5944 command instead of the more recent @code{dune} command while building
5945 a package. Its default value is @code{#f}.
5947 The @code{#:package} parameter can be passed to specify a package name, which
5948 is useful when a package contains multiple packages and you want to build
5949 only one of them. This is equivalent to passing the @code{-p} argument to
5953 @defvr {Scheme Variable} go-build-system
5954 This variable is exported by @code{(guix build-system go)}. It
5955 implements a build procedure for Go packages using the standard
5956 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5957 Go build mechanisms}.
5959 The user is expected to provide a value for the key @code{#:import-path}
5960 and, in some cases, @code{#:unpack-path}. The
5961 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5962 corresponds to the file system path expected by the package's build
5963 scripts and any referring packages, and provides a unique way to
5964 refer to a Go package. It is typically based on a combination of the
5965 package source code's remote URI and file system hierarchy structure. In
5966 some cases, you will need to unpack the package's source code to a
5967 different directory structure than the one indicated by the import path,
5968 and @code{#:unpack-path} should be used in such cases.
5970 Packages that provide Go libraries should install their source code into
5971 the built output. The key @code{#:install-source?}, which defaults to
5972 @code{#t}, controls whether or not the source code is installed. It can
5973 be set to @code{#f} for packages that only provide executable files.
5976 @defvr {Scheme Variable} glib-or-gtk-build-system
5977 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5978 is intended for use with packages making use of GLib or GTK+.
5980 This build system adds the following two phases to the ones defined by
5981 @var{gnu-build-system}:
5984 @item glib-or-gtk-wrap
5985 The phase @code{glib-or-gtk-wrap} ensures that programs in
5986 @file{bin/} are able to find GLib ``schemas'' and
5987 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5988 modules}. This is achieved by wrapping the programs in launch scripts
5989 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5990 environment variables.
5992 It is possible to exclude specific package outputs from that wrapping
5993 process by listing their names in the
5994 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5995 when an output is known not to contain any GLib or GTK+ binaries, and
5996 where wrapping would gratuitously add a dependency of that output on
5999 @item glib-or-gtk-compile-schemas
6000 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6001 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6002 GSettings schemas} of GLib are compiled. Compilation is performed by the
6003 @command{glib-compile-schemas} program. It is provided by the package
6004 @code{glib:bin} which is automatically imported by the build system.
6005 The @code{glib} package providing @command{glib-compile-schemas} can be
6006 specified with the @code{#:glib} parameter.
6009 Both phases are executed after the @code{install} phase.
6012 @defvr {Scheme Variable} guile-build-system
6013 This build system is for Guile packages that consist exclusively of Scheme
6014 code and that are so lean that they don't even have a makefile, let alone a
6015 @file{configure} script. It compiles Scheme code using @command{guild
6016 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6017 installs the @file{.scm} and @file{.go} files in the right place. It also
6018 installs documentation.
6020 This build system supports cross-compilation by using the @code{--target}
6021 option of @command{guild compile}.
6023 Packages built with @code{guile-build-system} must provide a Guile package in
6024 their @code{native-inputs} field.
6027 @defvr {Scheme Variable} minify-build-system
6028 This variable is exported by @code{(guix build-system minify)}. It
6029 implements a minification procedure for simple JavaScript packages.
6031 It adds @code{uglify-js} to the set of inputs and uses it to compress
6032 all JavaScript files in the @file{src} directory. A different minifier
6033 package can be specified with the @code{#:uglify-js} parameter, but it
6034 is expected that the package writes the minified code to the standard
6037 When the input JavaScript files are not all located in the @file{src}
6038 directory, the parameter @code{#:javascript-files} can be used to
6039 specify a list of file names to feed to the minifier.
6042 @defvr {Scheme Variable} ocaml-build-system
6043 This variable is exported by @code{(guix build-system ocaml)}. It implements
6044 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6045 of choosing the correct set of commands to run for each package. OCaml
6046 packages can expect many different commands to be run. This build system will
6049 When the package has a @file{setup.ml} file present at the top-level, it will
6050 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6051 @code{ocaml setup.ml -install}. The build system will assume that this file
6052 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6053 care of setting the prefix and enabling tests if they are not disabled. You
6054 can pass configure and build flags with the @code{#:configure-flags} and
6055 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6056 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6057 bypass this system in the build and install phases.
6059 When the package has a @file{configure} file, it is assumed that it is a
6060 hand-made configure script that requires a different argument format than
6061 in the @code{gnu-build-system}. You can add more flags with the
6062 @code{#:configure-flags} key.
6064 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6065 @code{#t}), it will be used and more flags can be passed to the build and
6066 install phases with the @code{#:make-flags} key.
6068 Finally, some packages do not have these files and use a somewhat standard
6069 location for its build system. In that case, the build system will run
6070 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6071 providing the path to the required findlib module. Additional flags can
6072 be passed via the @code{#:build-flags} key. Install is taken care of by
6073 @command{opam-installer}. In this case, the @code{opam} package must
6074 be added to the @code{native-inputs} field of the package definition.
6076 Note that most OCaml packages assume they will be installed in the same
6077 directory as OCaml, which is not what we want in guix. In particular, they
6078 will install @file{.so} files in their module's directory, which is usually
6079 fine because it is in the OCaml compiler directory. In guix though, these
6080 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6081 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6082 @file{.so} libraries should be installed.
6085 @defvr {Scheme Variable} python-build-system
6086 This variable is exported by @code{(guix build-system python)}. It
6087 implements the more or less standard build procedure used by Python
6088 packages, which consists in running @code{python setup.py build} and
6089 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6091 For packages that install stand-alone Python programs under @code{bin/},
6092 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6093 environment variable points to all the Python libraries they depend on.
6095 Which Python package is used to perform the build can be specified with
6096 the @code{#:python} parameter. This is a useful way to force a package
6097 to be built for a specific version of the Python interpreter, which
6098 might be necessary if the package is only compatible with a single
6099 interpreter version.
6101 By default guix calls @code{setup.py} under control of
6102 @code{setuptools}, much like @command{pip} does. Some packages are not
6103 compatible with setuptools (and pip), thus you can disable this by
6104 setting the @code{#:use-setuptools} parameter to @code{#f}.
6107 @defvr {Scheme Variable} perl-build-system
6108 This variable is exported by @code{(guix build-system perl)}. It
6109 implements the standard build procedure for Perl packages, which either
6110 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6111 followed by @code{Build} and @code{Build install}; or in running
6112 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6113 @code{make} and @code{make install}, depending on which of
6114 @code{Build.PL} or @code{Makefile.PL} is present in the package
6115 distribution. Preference is given to the former if both @code{Build.PL}
6116 and @code{Makefile.PL} exist in the package distribution. This
6117 preference can be reversed by specifying @code{#t} for the
6118 @code{#:make-maker?} parameter.
6120 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6121 passes flags specified by the @code{#:make-maker-flags} or
6122 @code{#:module-build-flags} parameter, respectively.
6124 Which Perl package is used can be specified with @code{#:perl}.
6127 @defvr {Scheme Variable} r-build-system
6128 This variable is exported by @code{(guix build-system r)}. It
6129 implements the build procedure used by @uref{https://r-project.org, R}
6130 packages, which essentially is little more than running @code{R CMD
6131 INSTALL --library=/gnu/store/@dots{}} in an environment where
6132 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6133 are run after installation using the R function
6134 @code{tools::testInstalledPackage}.
6137 @defvr {Scheme Variable} rakudo-build-system
6138 This variable is exported by @code{(guix build-system rakudo)}. It
6139 implements the build procedure used by @uref{https://rakudo.org/,
6140 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6141 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6142 installs the binaries, library files and the resources, as well as wrap
6143 the files under the @code{bin/} directory. Tests can be skipped by
6144 passing @code{#f} to the @code{tests?} parameter.
6146 Which rakudo package is used can be specified with @code{rakudo}.
6147 Which perl6-tap-harness package used for the tests can be specified with
6148 @code{#:prove6} or removed by passing @code{#f} to the
6149 @code{with-prove6?} parameter.
6150 Which perl6-zef package used for tests and installing can be specified
6151 with @code{#:zef} or removed by passing @code{#f} to the
6152 @code{with-zef?} parameter.
6155 @defvr {Scheme Variable} texlive-build-system
6156 This variable is exported by @code{(guix build-system texlive)}. It is
6157 used to build TeX packages in batch mode with a specified engine. The
6158 build system sets the @code{TEXINPUTS} variable to find all TeX source
6159 files in the inputs.
6161 By default it runs @code{luatex} on all files ending on @code{ins}. A
6162 different engine and format can be specified with the
6163 @code{#:tex-format} argument. Different build targets can be specified
6164 with the @code{#:build-targets} argument, which expects a list of file
6165 names. The build system adds only @code{texlive-bin} and
6166 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6167 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6168 and @code{#:texlive-latex-base}, respectively.
6170 The @code{#:tex-directory} parameter tells the build system where to
6171 install the built files under the texmf tree.
6174 @defvr {Scheme Variable} ruby-build-system
6175 This variable is exported by @code{(guix build-system ruby)}. It
6176 implements the RubyGems build procedure used by Ruby packages, which
6177 involves running @code{gem build} followed by @code{gem install}.
6179 The @code{source} field of a package that uses this build system
6180 typically references a gem archive, since this is the format that Ruby
6181 developers use when releasing their software. The build system unpacks
6182 the gem archive, potentially patches the source, runs the test suite,
6183 repackages the gem, and installs it. Additionally, directories and
6184 tarballs may be referenced to allow building unreleased gems from Git or
6185 a traditional source release tarball.
6187 Which Ruby package is used can be specified with the @code{#:ruby}
6188 parameter. A list of additional flags to be passed to the @command{gem}
6189 command can be specified with the @code{#:gem-flags} parameter.
6192 @defvr {Scheme Variable} waf-build-system
6193 This variable is exported by @code{(guix build-system waf)}. It
6194 implements a build procedure around the @code{waf} script. The common
6195 phases---@code{configure}, @code{build}, and @code{install}---are
6196 implemented by passing their names as arguments to the @code{waf}
6199 The @code{waf} script is executed by the Python interpreter. Which
6200 Python package is used to run the script can be specified with the
6201 @code{#:python} parameter.
6204 @defvr {Scheme Variable} scons-build-system
6205 This variable is exported by @code{(guix build-system scons)}. It
6206 implements the build procedure used by the SCons software construction
6207 tool. This build system runs @code{scons} to build the package,
6208 @code{scons test} to run tests, and then @code{scons install} to install
6211 Additional flags to be passed to @code{scons} can be specified with the
6212 @code{#:scons-flags} parameter. The version of Python used to run SCons
6213 can be specified by selecting the appropriate SCons package with the
6214 @code{#:scons} parameter.
6217 @defvr {Scheme Variable} haskell-build-system
6218 This variable is exported by @code{(guix build-system haskell)}. It
6219 implements the Cabal build procedure used by Haskell packages, which
6220 involves running @code{runhaskell Setup.hs configure
6221 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6222 Instead of installing the package by running @code{runhaskell Setup.hs
6223 install}, to avoid trying to register libraries in the read-only
6224 compiler store directory, the build system uses @code{runhaskell
6225 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6226 addition, the build system generates the package documentation by
6227 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6228 is passed. Optional Haddock parameters can be passed with the help of
6229 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6230 not found, the build system looks for @code{Setup.lhs} instead.
6232 Which Haskell compiler is used can be specified with the @code{#:haskell}
6233 parameter which defaults to @code{ghc}.
6236 @defvr {Scheme Variable} dub-build-system
6237 This variable is exported by @code{(guix build-system dub)}. It
6238 implements the Dub build procedure used by D packages, which
6239 involves running @code{dub build} and @code{dub run}.
6240 Installation is done by copying the files manually.
6242 Which D compiler is used can be specified with the @code{#:ldc}
6243 parameter which defaults to @code{ldc}.
6246 @defvr {Scheme Variable} emacs-build-system
6247 This variable is exported by @code{(guix build-system emacs)}. It
6248 implements an installation procedure similar to the packaging system
6249 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6251 It first creates the @code{@var{package}-autoloads.el} file, then it
6252 byte compiles all Emacs Lisp files. Differently from the Emacs
6253 packaging system, the Info documentation files are moved to the standard
6254 documentation directory and the @file{dir} file is deleted. Each
6255 package is installed in its own directory under
6256 @file{share/emacs/site-lisp/guix.d}.
6259 @defvr {Scheme Variable} font-build-system
6260 This variable is exported by @code{(guix build-system font)}. It
6261 implements an installation procedure for font packages where upstream
6262 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6263 need to be copied into place. It copies font files to standard
6264 locations in the output directory.
6267 @defvr {Scheme Variable} meson-build-system
6268 This variable is exported by @code{(guix build-system meson)}. It
6269 implements the build procedure for packages that use
6270 @url{https://mesonbuild.com, Meson} as their build system.
6272 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6273 of inputs, and they can be changed with the parameters @code{#:meson}
6274 and @code{#:ninja} if needed. The default Meson is
6275 @code{meson-for-build}, which is special because it doesn't clear the
6276 @code{RUNPATH} of binaries and libraries when they are installed.
6278 This build system is an extension of @var{gnu-build-system}, but with the
6279 following phases changed to some specific for Meson:
6284 The phase runs @code{meson} with the flags specified in
6285 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6286 @code{plain} unless something else is specified in @code{#:build-type}.
6289 The phase runs @code{ninja} to build the package in parallel by default, but
6290 this can be changed with @code{#:parallel-build?}.
6293 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6294 which is @code{"test"} by default.
6297 The phase runs @code{ninja install} and can not be changed.
6300 Apart from that, the build system also adds the following phases:
6305 This phase ensures that all binaries can find the libraries they need.
6306 It searches for required libraries in subdirectories of the package being
6307 built, and adds those to @code{RUNPATH} where needed. It also removes
6308 references to libraries left over from the build phase by
6309 @code{meson-for-build}, such as test dependencies, that aren't actually
6310 required for the program to run.
6312 @item glib-or-gtk-wrap
6313 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6314 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6316 @item glib-or-gtk-compile-schemas
6317 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6318 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6322 @defvr {Scheme Variable} linux-module-build-system
6323 @var{linux-module-build-system} allows building Linux kernel modules.
6325 @cindex build phases
6326 This build system is an extension of @var{gnu-build-system}, but with the
6327 following phases changed:
6332 This phase configures the environment so that the Linux kernel's Makefile
6333 can be used to build the external kernel module.
6336 This phase uses the Linux kernel's Makefile in order to build the external
6340 This phase uses the Linux kernel's Makefile in order to install the external
6344 It is possible and useful to specify the Linux kernel to use for building
6345 the module (in the "arguments" form of a package using the
6346 linux-module-build-system, use the key #:linux to specify it).
6349 Lastly, for packages that do not need anything as sophisticated, a
6350 ``trivial'' build system is provided. It is trivial in the sense that
6351 it provides basically no support: it does not pull any implicit inputs,
6352 and does not have a notion of build phases.
6354 @defvr {Scheme Variable} trivial-build-system
6355 This variable is exported by @code{(guix build-system trivial)}.
6357 This build system requires a @code{#:builder} argument. This argument
6358 must be a Scheme expression that builds the package output(s)---as
6359 with @code{build-expression->derivation} (@pxref{Derivations,
6360 @code{build-expression->derivation}}).
6370 Conceptually, the @dfn{store} is the place where derivations that have
6371 been built successfully are stored---by default, @file{/gnu/store}.
6372 Sub-directories in the store are referred to as @dfn{store items} or
6373 sometimes @dfn{store paths}. The store has an associated database that
6374 contains information such as the store paths referred to by each store
6375 path, and the list of @emph{valid} store items---results of successful
6376 builds. This database resides in @file{@var{localstatedir}/guix/db},
6377 where @var{localstatedir} is the state directory specified @i{via}
6378 @option{--localstatedir} at configure time, usually @file{/var}.
6380 The store is @emph{always} accessed by the daemon on behalf of its clients
6381 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6382 connect to the daemon over a Unix-domain socket, send requests to it,
6383 and read the result---these are remote procedure calls, or RPCs.
6386 Users must @emph{never} modify files under @file{/gnu/store} directly.
6387 This would lead to inconsistencies and break the immutability
6388 assumptions of Guix's functional model (@pxref{Introduction}).
6390 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6391 how to check the integrity of the store and attempt recovery from
6392 accidental modifications.
6395 The @code{(guix store)} module provides procedures to connect to the
6396 daemon, and to perform RPCs. These are described below. By default,
6397 @code{open-connection}, and thus all the @command{guix} commands,
6398 connect to the local daemon or to the URI specified by the
6399 @code{GUIX_DAEMON_SOCKET} environment variable.
6401 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6402 When set, the value of this variable should be a file name or a URI
6403 designating the daemon endpoint. When it is a file name, it denotes a
6404 Unix-domain socket to connect to. In addition to file names, the
6405 supported URI schemes are:
6410 These are for Unix-domain sockets.
6411 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6412 @file{/var/guix/daemon-socket/socket}.
6415 @cindex daemon, remote access
6416 @cindex remote access to the daemon
6417 @cindex daemon, cluster setup
6418 @cindex clusters, daemon setup
6419 These URIs denote connections over TCP/IP, without encryption nor
6420 authentication of the remote host. The URI must specify the host name
6421 and optionally a port number (by default port 44146 is used):
6424 guix://master.guix.example.org:1234
6427 This setup is suitable on local networks, such as clusters, where only
6428 trusted nodes may connect to the build daemon at
6429 @code{master.guix.example.org}.
6431 The @code{--listen} option of @command{guix-daemon} can be used to
6432 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6436 @cindex SSH access to build daemons
6437 These URIs allow you to connect to a remote daemon over
6438 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6439 A typical URL might look like this:
6442 ssh://charlie@@guix.example.org:22
6445 As for @command{guix copy}, the usual OpenSSH client configuration files
6446 are honored (@pxref{Invoking guix copy}).
6449 Additional URI schemes may be supported in the future.
6451 @c XXX: Remove this note when the protocol incurs fewer round trips
6452 @c and when (guix derivations) no longer relies on file system access.
6454 The ability to connect to remote build daemons is considered
6455 experimental as of @value{VERSION}. Please get in touch with us to
6456 share any problems or suggestions you may have (@pxref{Contributing}).
6460 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6461 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6462 @var{reserve-space?} is true, instruct it to reserve a little bit of
6463 extra space on the file system so that the garbage collector can still
6464 operate should the disk become full. Return a server object.
6466 @var{file} defaults to @code{%default-socket-path}, which is the normal
6467 location given the options that were passed to @command{configure}.
6470 @deffn {Scheme Procedure} close-connection @var{server}
6471 Close the connection to @var{server}.
6474 @defvr {Scheme Variable} current-build-output-port
6475 This variable is bound to a SRFI-39 parameter, which refers to the port
6476 where build and error logs sent by the daemon should be written.
6479 Procedures that make RPCs all take a server object as their first
6482 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6483 @cindex invalid store items
6484 Return @code{#t} when @var{path} designates a valid store item and
6485 @code{#f} otherwise (an invalid item may exist on disk but still be
6486 invalid, for instance because it is the result of an aborted or failed
6489 A @code{&store-protocol-error} condition is raised if @var{path} is not
6490 prefixed by the store directory (@file{/gnu/store}).
6493 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6494 Add @var{text} under file @var{name} in the store, and return its store
6495 path. @var{references} is the list of store paths referred to by the
6496 resulting store path.
6499 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6501 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6502 file names, or derivation/output pairs, using the specified
6503 @var{mode}---@code{(build-mode normal)} by default.
6506 Note that the @code{(guix monads)} module provides a monad as well as
6507 monadic versions of the above procedures, with the goal of making it
6508 more convenient to work with code that accesses the store (@pxref{The
6512 @i{This section is currently incomplete.}
6515 @section Derivations
6518 Low-level build actions and the environment in which they are performed
6519 are represented by @dfn{derivations}. A derivation contains the
6520 following pieces of information:
6524 The outputs of the derivation---derivations produce at least one file or
6525 directory in the store, but may produce more.
6528 @cindex build-time dependencies
6529 @cindex dependencies, build-time
6530 The inputs of the derivations---i.e., its build-time dependencies---which may
6531 be other derivations or plain files in the store (patches, build scripts,
6535 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6538 The file name of a build script in the store, along with the arguments
6542 A list of environment variables to be defined.
6546 @cindex derivation path
6547 Derivations allow clients of the daemon to communicate build actions to
6548 the store. They exist in two forms: as an in-memory representation,
6549 both on the client- and daemon-side, and as files in the store whose
6550 name end in @code{.drv}---these files are referred to as @dfn{derivation
6551 paths}. Derivations paths can be passed to the @code{build-derivations}
6552 procedure to perform the build actions they prescribe (@pxref{The
6555 @cindex fixed-output derivations
6556 Operations such as file downloads and version-control checkouts for
6557 which the expected content hash is known in advance are modeled as
6558 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6559 of a fixed-output derivation are independent of its inputs---e.g., a
6560 source code download produces the same result regardless of the download
6561 method and tools being used.
6564 @cindex run-time dependencies
6565 @cindex dependencies, run-time
6566 The outputs of derivations---i.e., the build results---have a set of
6567 @dfn{references}, as reported by the @code{references} RPC or the
6568 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6569 are the set of run-time dependencies of the build results. References are a
6570 subset of the inputs of the derivation; this subset is automatically computed
6571 by the build daemon by scanning all the files in the outputs.
6573 The @code{(guix derivations)} module provides a representation of
6574 derivations as Scheme objects, along with procedures to create and
6575 otherwise manipulate derivations. The lowest-level primitive to create
6576 a derivation is the @code{derivation} procedure:
6578 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6579 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6580 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6581 [#:system (%current-system)] [#:references-graphs #f] @
6582 [#:allowed-references #f] [#:disallowed-references #f] @
6583 [#:leaked-env-vars #f] [#:local-build? #f] @
6584 [#:substitutable? #t] [#:properties '()]
6585 Build a derivation with the given arguments, and return the resulting
6586 @code{<derivation>} object.
6588 When @var{hash} and @var{hash-algo} are given, a
6589 @dfn{fixed-output derivation} is created---i.e., one whose result is
6590 known in advance, such as a file download. If, in addition,
6591 @var{recursive?} is true, then that fixed output may be an executable
6592 file or a directory and @var{hash} must be the hash of an archive
6593 containing this output.
6595 When @var{references-graphs} is true, it must be a list of file
6596 name/store path pairs. In that case, the reference graph of each store
6597 path is exported in the build environment in the corresponding file, in
6598 a simple text format.
6600 When @var{allowed-references} is true, it must be a list of store items
6601 or outputs that the derivation's output may refer to. Likewise,
6602 @var{disallowed-references}, if true, must be a list of things the
6603 outputs may @emph{not} refer to.
6605 When @var{leaked-env-vars} is true, it must be a list of strings
6606 denoting environment variables that are allowed to ``leak'' from the
6607 daemon's environment to the build environment. This is only applicable
6608 to fixed-output derivations---i.e., when @var{hash} is true. The main
6609 use is to allow variables such as @code{http_proxy} to be passed to
6610 derivations that download files.
6612 When @var{local-build?} is true, declare that the derivation is not a
6613 good candidate for offloading and should rather be built locally
6614 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6615 where the costs of data transfers would outweigh the benefits.
6617 When @var{substitutable?} is false, declare that substitutes of the
6618 derivation's output should not be used (@pxref{Substitutes}). This is
6619 useful, for instance, when building packages that capture details of the
6620 host CPU instruction set.
6622 @var{properties} must be an association list describing ``properties'' of the
6623 derivation. It is kept as-is, uninterpreted, in the derivation.
6627 Here's an example with a shell script as its builder, assuming
6628 @var{store} is an open connection to the daemon, and @var{bash} points
6629 to a Bash executable in the store:
6632 (use-modules (guix utils)
6636 (let ((builder ; add the Bash script to the store
6637 (add-text-to-store store "my-builder.sh"
6638 "echo hello world > $out\n" '())))
6639 (derivation store "foo"
6640 bash `("-e" ,builder)
6641 #:inputs `((,bash) (,builder))
6642 #:env-vars '(("HOME" . "/homeless"))))
6643 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6646 As can be guessed, this primitive is cumbersome to use directly. A
6647 better approach is to write build scripts in Scheme, of course! The
6648 best course of action for that is to write the build code as a
6649 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6650 information, @pxref{G-Expressions}.
6652 Once upon a time, @code{gexp->derivation} did not exist and constructing
6653 derivations with build code written in Scheme was achieved with
6654 @code{build-expression->derivation}, documented below. This procedure
6655 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6657 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6658 @var{name} @var{exp} @
6659 [#:system (%current-system)] [#:inputs '()] @
6660 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6661 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6662 [#:references-graphs #f] [#:allowed-references #f] @
6663 [#:disallowed-references #f] @
6664 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6665 Return a derivation that executes Scheme expression @var{exp} as a
6666 builder for derivation @var{name}. @var{inputs} must be a list of
6667 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6668 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6669 modules from the current search path to be copied in the store,
6670 compiled, and made available in the load path during the execution of
6671 @var{exp}---e.g., @code{((guix build utils) (guix build
6672 gnu-build-system))}.
6674 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6675 to a list of output/path pairs, and where @code{%build-inputs} is bound
6676 to a list of string/output-path pairs made from @var{inputs}.
6677 Optionally, @var{env-vars} is a list of string pairs specifying the name
6678 and value of environment variables visible to the builder. The builder
6679 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6680 @var{exp} returns @code{#f}, the build is considered to have failed.
6682 @var{exp} is built using @var{guile-for-build} (a derivation). When
6683 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6684 @code{%guile-for-build} fluid is used instead.
6686 See the @code{derivation} procedure for the meaning of
6687 @var{references-graphs}, @var{allowed-references},
6688 @var{disallowed-references}, @var{local-build?}, and
6689 @var{substitutable?}.
6693 Here's an example of a single-output derivation that creates a directory
6694 containing one file:
6697 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6698 (mkdir out) ; create /gnu/store/@dots{}-goo
6699 (call-with-output-file (string-append out "/test")
6701 (display '(hello guix) p))))))
6702 (build-expression->derivation store "goo" builder))
6704 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6708 @node The Store Monad
6709 @section The Store Monad
6713 The procedures that operate on the store described in the previous
6714 sections all take an open connection to the build daemon as their first
6715 argument. Although the underlying model is functional, they either have
6716 side effects or depend on the current state of the store.
6718 The former is inconvenient: the connection to the build daemon has to be
6719 carried around in all those functions, making it impossible to compose
6720 functions that do not take that parameter with functions that do. The
6721 latter can be problematic: since store operations have side effects
6722 and/or depend on external state, they have to be properly sequenced.
6724 @cindex monadic values
6725 @cindex monadic functions
6726 This is where the @code{(guix monads)} module comes in. This module
6727 provides a framework for working with @dfn{monads}, and a particularly
6728 useful monad for our uses, the @dfn{store monad}. Monads are a
6729 construct that allows two things: associating ``context'' with values
6730 (in our case, the context is the store), and building sequences of
6731 computations (here computations include accesses to the store). Values
6732 in a monad---values that carry this additional context---are called
6733 @dfn{monadic values}; procedures that return such values are called
6734 @dfn{monadic procedures}.
6736 Consider this ``normal'' procedure:
6739 (define (sh-symlink store)
6740 ;; Return a derivation that symlinks the 'bash' executable.
6741 (let* ((drv (package-derivation store bash))
6742 (out (derivation->output-path drv))
6743 (sh (string-append out "/bin/bash")))
6744 (build-expression->derivation store "sh"
6745 `(symlink ,sh %output))))
6748 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6749 as a monadic function:
6752 (define (sh-symlink)
6753 ;; Same, but return a monadic value.
6754 (mlet %store-monad ((drv (package->derivation bash)))
6755 (gexp->derivation "sh"
6756 #~(symlink (string-append #$drv "/bin/bash")
6760 There are several things to note in the second version: the @code{store}
6761 parameter is now implicit and is ``threaded'' in the calls to the
6762 @code{package->derivation} and @code{gexp->derivation} monadic
6763 procedures, and the monadic value returned by @code{package->derivation}
6764 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6766 As it turns out, the call to @code{package->derivation} can even be
6767 omitted since it will take place implicitly, as we will see later
6768 (@pxref{G-Expressions}):
6771 (define (sh-symlink)
6772 (gexp->derivation "sh"
6773 #~(symlink (string-append #$bash "/bin/bash")
6778 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6779 @c for the funny quote.
6780 Calling the monadic @code{sh-symlink} has no effect. As someone once
6781 said, ``you exit a monad like you exit a building on fire: by running''.
6782 So, to exit the monad and get the desired effect, one must use
6783 @code{run-with-store}:
6786 (run-with-store (open-connection) (sh-symlink))
6787 @result{} /gnu/store/...-sh-symlink
6790 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6791 new ``meta-commands'' to make it easier to deal with monadic procedures:
6792 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6793 to ``run'' a single monadic value through the store:
6796 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6797 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6800 The latter enters a recursive REPL, where all the return values are
6801 automatically run through the store:
6804 scheme@@(guile-user)> ,enter-store-monad
6805 store-monad@@(guile-user) [1]> (package->derivation hello)
6806 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6807 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6808 $3 = "/gnu/store/@dots{}-foo"
6809 store-monad@@(guile-user) [1]> ,q
6810 scheme@@(guile-user)>
6814 Note that non-monadic values cannot be returned in the
6815 @code{store-monad} REPL.
6817 The main syntactic forms to deal with monads in general are provided by
6818 the @code{(guix monads)} module and are described below.
6820 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6821 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6825 @deffn {Scheme Syntax} return @var{val}
6826 Return a monadic value that encapsulates @var{val}.
6829 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6830 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6831 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6832 referred to as ``bind'', but that name denotes an unrelated procedure in
6833 Guile. Thus we use this somewhat cryptic symbol inherited from the
6834 Haskell language.}. There can be one @var{mproc} or several of them, as
6839 (with-monad %state-monad
6841 (lambda (x) (return (+ 1 x)))
6842 (lambda (x) (return (* 2 x)))))
6846 @result{} some-state
6850 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6852 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6854 Bind the variables @var{var} to the monadic values @var{mval} in
6855 @var{body}, which is a sequence of expressions. As with the bind
6856 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6857 value ``contained'' in @var{mval} and making @var{var} refer to that
6858 raw, non-monadic value within the scope of the @var{body}. The form
6859 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6860 @var{val}, as per @code{let}. The binding operations occur in sequence
6861 from left to right. The last expression of @var{body} must be a monadic
6862 expression, and its result will become the result of the @code{mlet} or
6863 @code{mlet*} when run in the @var{monad}.
6865 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6866 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6869 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6870 Bind @var{mexp} and the following monadic expressions in sequence,
6871 returning the result of the last expression. Every expression in the
6872 sequence must be a monadic expression.
6874 This is akin to @code{mlet}, except that the return values of the
6875 monadic expressions are ignored. In that sense, it is analogous to
6876 @code{begin}, but applied to monadic expressions.
6879 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6880 When @var{condition} is true, evaluate the sequence of monadic
6881 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6882 @var{condition} is false, return @code{*unspecified*} in the current
6883 monad. Every expression in the sequence must be a monadic expression.
6886 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6887 When @var{condition} is false, evaluate the sequence of monadic
6888 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6889 @var{condition} is true, return @code{*unspecified*} in the current
6890 monad. Every expression in the sequence must be a monadic expression.
6894 The @code{(guix monads)} module provides the @dfn{state monad}, which
6895 allows an additional value---the state---to be @emph{threaded} through
6896 monadic procedure calls.
6898 @defvr {Scheme Variable} %state-monad
6899 The state monad. Procedures in the state monad can access and change
6900 the state that is threaded.
6902 Consider the example below. The @code{square} procedure returns a value
6903 in the state monad. It returns the square of its argument, but also
6904 increments the current state value:
6908 (mlet %state-monad ((count (current-state)))
6909 (mbegin %state-monad
6910 (set-current-state (+ 1 count))
6913 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6918 When ``run'' through @var{%state-monad}, we obtain that additional state
6919 value, which is the number of @code{square} calls.
6922 @deffn {Monadic Procedure} current-state
6923 Return the current state as a monadic value.
6926 @deffn {Monadic Procedure} set-current-state @var{value}
6927 Set the current state to @var{value} and return the previous state as a
6931 @deffn {Monadic Procedure} state-push @var{value}
6932 Push @var{value} to the current state, which is assumed to be a list,
6933 and return the previous state as a monadic value.
6936 @deffn {Monadic Procedure} state-pop
6937 Pop a value from the current state and return it as a monadic value.
6938 The state is assumed to be a list.
6941 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6942 Run monadic value @var{mval} starting with @var{state} as the initial
6943 state. Return two values: the resulting value, and the resulting state.
6946 The main interface to the store monad, provided by the @code{(guix
6947 store)} module, is as follows.
6949 @defvr {Scheme Variable} %store-monad
6950 The store monad---an alias for @var{%state-monad}.
6952 Values in the store monad encapsulate accesses to the store. When its
6953 effect is needed, a value of the store monad must be ``evaluated'' by
6954 passing it to the @code{run-with-store} procedure (see below.)
6957 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6958 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6959 open store connection.
6962 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6963 Return as a monadic value the absolute file name in the store of the file
6964 containing @var{text}, a string. @var{references} is a list of store items that the
6965 resulting text file refers to; it defaults to the empty list.
6968 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6969 Return as a monadic value the absolute file name in the store of the file
6970 containing @var{data}, a bytevector. @var{references} is a list of store
6971 items that the resulting binary file refers to; it defaults to the empty list.
6974 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6975 [#:recursive? #t] [#:select? (const #t)]
6976 Return the name of @var{file} once interned in the store. Use
6977 @var{name} as its store name, or the basename of @var{file} if
6978 @var{name} is omitted.
6980 When @var{recursive?} is true, the contents of @var{file} are added
6981 recursively; if @var{file} designates a flat file and @var{recursive?}
6982 is true, its contents are added, and its permission bits are kept.
6984 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6985 @var{stat})} for each directory entry, where @var{file} is the entry's
6986 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6987 entries for which @var{select?} does not return true.
6989 The example below adds a file to the store, under two different names:
6992 (run-with-store (open-connection)
6993 (mlet %store-monad ((a (interned-file "README"))
6994 (b (interned-file "README" "LEGU-MIN")))
6995 (return (list a b))))
6997 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7002 The @code{(guix packages)} module exports the following package-related
7005 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7006 [#:system (%current-system)] [#:target #f] @
7009 value in the absolute file name of @var{file} within the @var{output}
7010 directory of @var{package}. When @var{file} is omitted, return the name
7011 of the @var{output} directory of @var{package}. When @var{target} is
7012 true, use it as a cross-compilation target triplet.
7015 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7016 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7017 @var{target} [@var{system}]
7018 Monadic version of @code{package-derivation} and
7019 @code{package-cross-derivation} (@pxref{Defining Packages}).
7024 @section G-Expressions
7026 @cindex G-expression
7027 @cindex build code quoting
7028 So we have ``derivations'', which represent a sequence of build actions
7029 to be performed to produce an item in the store (@pxref{Derivations}).
7030 These build actions are performed when asking the daemon to actually
7031 build the derivations; they are run by the daemon in a container
7032 (@pxref{Invoking guix-daemon}).
7034 @cindex strata of code
7035 It should come as no surprise that we like to write these build actions
7036 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7037 code@footnote{The term @dfn{stratum} in this context was coined by
7038 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7039 Kiselyov, who has written insightful
7040 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7041 on this topic}, refers to this kind of code generation as
7042 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7043 to the daemon, etc.---and the ``build code''---code that actually
7044 performs build actions, such as making directories, invoking
7045 @command{make}, etc.
7047 To describe a derivation and its build actions, one typically needs to
7048 embed build code inside host code. It boils down to manipulating build
7049 code as data, and the homoiconicity of Scheme---code has a direct
7050 representation as data---comes in handy for that. But we need more than
7051 the normal @code{quasiquote} mechanism in Scheme to construct build
7054 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7055 S-expressions adapted to build expressions. G-expressions, or
7056 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7057 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7058 @code{#$}, and @code{#$@@}), which are comparable to
7059 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7060 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7061 GNU Guile Reference Manual}). However, there are major differences:
7065 Gexps are meant to be written to a file and run or manipulated by other
7069 When a high-level object such as a package or derivation is unquoted
7070 inside a gexp, the result is as if its output file name had been
7074 Gexps carry information about the packages or derivations they refer to,
7075 and these dependencies are automatically added as inputs to the build
7076 processes that use them.
7079 @cindex lowering, of high-level objects in gexps
7080 This mechanism is not limited to package and derivation
7081 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7082 derivations or files in the store can be defined,
7083 such that these objects can also be inserted
7084 into gexps. For example, a useful type of high-level objects that can be
7085 inserted in a gexp is ``file-like objects'', which make it easy to
7086 add files to the store and to refer to them in
7087 derivations and such (see @code{local-file} and @code{plain-file}
7090 To illustrate the idea, here is an example of a gexp:
7097 (symlink (string-append #$coreutils "/bin/ls")
7101 This gexp can be passed to @code{gexp->derivation}; we obtain a
7102 derivation that builds a directory containing exactly one symlink to
7103 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7106 (gexp->derivation "the-thing" build-exp)
7109 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7110 substituted to the reference to the @var{coreutils} package in the
7111 actual build code, and @var{coreutils} is automatically made an input to
7112 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7113 output)}) is replaced by a string containing the directory name of the
7114 output of the derivation.
7116 @cindex cross compilation
7117 In a cross-compilation context, it is useful to distinguish between
7118 references to the @emph{native} build of a package---that can run on the
7119 host---versus references to cross builds of a package. To that end, the
7120 @code{#+} plays the same role as @code{#$}, but is a reference to a
7121 native package build:
7124 (gexp->derivation "vi"
7127 (system* (string-append #+coreutils "/bin/ln")
7129 (string-append #$emacs "/bin/emacs")
7130 (string-append #$output "/bin/vi")))
7131 #:target "mips64el-linux-gnu")
7135 In the example above, the native build of @var{coreutils} is used, so
7136 that @command{ln} can actually run on the host; but then the
7137 cross-compiled build of @var{emacs} is referenced.
7139 @cindex imported modules, for gexps
7140 @findex with-imported-modules
7141 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7142 able to use certain Guile modules from the ``host environment'' in the
7143 gexp, so those modules should be imported in the ``build environment''.
7144 The @code{with-imported-modules} form allows you to express that:
7147 (let ((build (with-imported-modules '((guix build utils))
7149 (use-modules (guix build utils))
7150 (mkdir-p (string-append #$output "/bin"))))))
7151 (gexp->derivation "empty-dir"
7154 (display "success!\n")
7159 In this example, the @code{(guix build utils)} module is automatically
7160 pulled into the isolated build environment of our gexp, such that
7161 @code{(use-modules (guix build utils))} works as expected.
7163 @cindex module closure
7164 @findex source-module-closure
7165 Usually you want the @emph{closure} of the module to be imported---i.e.,
7166 the module itself and all the modules it depends on---rather than just
7167 the module; failing to do that, attempts to use the module will fail
7168 because of missing dependent modules. The @code{source-module-closure}
7169 procedure computes the closure of a module by looking at its source file
7170 headers, which comes in handy in this case:
7173 (use-modules (guix modules)) ;for 'source-module-closure'
7175 (with-imported-modules (source-module-closure
7176 '((guix build utils)
7178 (gexp->derivation "something-with-vms"
7180 (use-modules (guix build utils)
7185 @cindex extensions, for gexps
7186 @findex with-extensions
7187 In the same vein, sometimes you want to import not just pure-Scheme
7188 modules, but also ``extensions'' such as Guile bindings to C libraries
7189 or other ``full-blown'' packages. Say you need the @code{guile-json}
7190 package available on the build side, here's how you would do it:
7193 (use-modules (gnu packages guile)) ;for 'guile-json'
7195 (with-extensions (list guile-json)
7196 (gexp->derivation "something-with-json"
7198 (use-modules (json))
7202 The syntactic form to construct gexps is summarized below.
7204 @deffn {Scheme Syntax} #~@var{exp}
7205 @deffnx {Scheme Syntax} (gexp @var{exp})
7206 Return a G-expression containing @var{exp}. @var{exp} may contain one
7207 or more of the following forms:
7211 @itemx (ungexp @var{obj})
7212 Introduce a reference to @var{obj}. @var{obj} may have one of the
7213 supported types, for example a package or a
7214 derivation, in which case the @code{ungexp} form is replaced by its
7215 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7217 If @var{obj} is a list, it is traversed and references to supported
7218 objects are substituted similarly.
7220 If @var{obj} is another gexp, its contents are inserted and its
7221 dependencies are added to those of the containing gexp.
7223 If @var{obj} is another kind of object, it is inserted as is.
7225 @item #$@var{obj}:@var{output}
7226 @itemx (ungexp @var{obj} @var{output})
7227 This is like the form above, but referring explicitly to the
7228 @var{output} of @var{obj}---this is useful when @var{obj} produces
7229 multiple outputs (@pxref{Packages with Multiple Outputs}).
7232 @itemx #+@var{obj}:output
7233 @itemx (ungexp-native @var{obj})
7234 @itemx (ungexp-native @var{obj} @var{output})
7235 Same as @code{ungexp}, but produces a reference to the @emph{native}
7236 build of @var{obj} when used in a cross compilation context.
7238 @item #$output[:@var{output}]
7239 @itemx (ungexp output [@var{output}])
7240 Insert a reference to derivation output @var{output}, or to the main
7241 output when @var{output} is omitted.
7243 This only makes sense for gexps passed to @code{gexp->derivation}.
7246 @itemx (ungexp-splicing @var{lst})
7247 Like the above, but splices the contents of @var{lst} inside the
7251 @itemx (ungexp-native-splicing @var{lst})
7252 Like the above, but refers to native builds of the objects listed in
7257 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7258 of the @code{gexp?} type (see below.)
7261 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7262 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7263 in their execution environment.
7265 Each item in @var{modules} can be the name of a module, such as
7266 @code{(guix build utils)}, or it can be a module name, followed by an
7267 arrow, followed by a file-like object:
7270 `((guix build utils)
7272 ((guix config) => ,(scheme-file "config.scm"
7273 #~(define-module @dots{}))))
7277 In the example above, the first two modules are taken from the search
7278 path, and the last one is created from the given file-like object.
7280 This form has @emph{lexical} scope: it has an effect on the gexps
7281 directly defined in @var{body}@dots{}, but not on those defined, say, in
7282 procedures called from @var{body}@dots{}.
7285 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7286 Mark the gexps defined in @var{body}@dots{} as requiring
7287 @var{extensions} in their build and execution environment.
7288 @var{extensions} is typically a list of package objects such as those
7289 defined in the @code{(gnu packages guile)} module.
7291 Concretely, the packages listed in @var{extensions} are added to the
7292 load path while compiling imported modules in @var{body}@dots{}; they
7293 are also added to the load path of the gexp returned by
7297 @deffn {Scheme Procedure} gexp? @var{obj}
7298 Return @code{#t} if @var{obj} is a G-expression.
7301 G-expressions are meant to be written to disk, either as code building
7302 some derivation, or as plain files in the store. The monadic procedures
7303 below allow you to do that (@pxref{The Store Monad}, for more
7304 information about monads.)
7306 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7307 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7308 [#:hash #f] [#:hash-algo #f] @
7309 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7310 [#:module-path @var{%load-path}] @
7311 [#:effective-version "2.2"] @
7312 [#:references-graphs #f] [#:allowed-references #f] @
7313 [#:disallowed-references #f] @
7314 [#:leaked-env-vars #f] @
7315 [#:script-name (string-append @var{name} "-builder")] @
7316 [#:deprecation-warnings #f] @
7317 [#:local-build? #f] [#:substitutable? #t] @
7318 [#:properties '()] [#:guile-for-build #f]
7319 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7320 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7321 stored in a file called @var{script-name}. When @var{target} is true,
7322 it is used as the cross-compilation target triplet for packages referred
7325 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7327 make @var{modules} available in the evaluation context of @var{exp};
7328 @var{modules} is a list of names of Guile modules searched in
7329 @var{module-path} to be copied in the store, compiled, and made available in
7330 the load path during the execution of @var{exp}---e.g., @code{((guix
7331 build utils) (guix build gnu-build-system))}.
7333 @var{effective-version} determines the string to use when adding extensions of
7334 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7336 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7339 When @var{references-graphs} is true, it must be a list of tuples of one of the
7343 (@var{file-name} @var{package})
7344 (@var{file-name} @var{package} @var{output})
7345 (@var{file-name} @var{derivation})
7346 (@var{file-name} @var{derivation} @var{output})
7347 (@var{file-name} @var{store-item})
7350 The right-hand-side of each element of @var{references-graphs} is automatically made
7351 an input of the build process of @var{exp}. In the build environment, each
7352 @var{file-name} contains the reference graph of the corresponding item, in a simple
7355 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7356 In the latter case, the list denotes store items that the result is allowed to
7357 refer to. Any reference to another store item will lead to a build error.
7358 Similarly for @var{disallowed-references}, which can list items that must not be
7359 referenced by the outputs.
7361 @var{deprecation-warnings} determines whether to show deprecation warnings while
7362 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7364 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7367 @cindex file-like objects
7368 The @code{local-file}, @code{plain-file}, @code{computed-file},
7369 @code{program-file}, and @code{scheme-file} procedures below return
7370 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7371 these objects lead to a file in the store. Consider this G-expression:
7374 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7375 #$(local-file "/tmp/my-nscd.conf"))
7378 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7379 to the store. Once expanded, for instance @i{via}
7380 @code{gexp->derivation}, the G-expression refers to that copy under
7381 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7382 does not have any effect on what the G-expression does.
7383 @code{plain-file} can be used similarly; it differs in that the file
7384 content is directly passed as a string.
7386 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7387 [#:recursive? #f] [#:select? (const #t)]
7388 Return an object representing local file @var{file} to add to the store; this
7389 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7390 up relative to the source file where this form appears. @var{file} will be added to
7391 the store under @var{name}--by default the base name of @var{file}.
7393 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7394 designates a flat file and @var{recursive?} is true, its contents are added, and its
7395 permission bits are kept.
7397 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7398 @var{stat})} for each directory entry, where @var{file} is the entry's
7399 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7400 entries for which @var{select?} does not return true.
7402 This is the declarative counterpart of the @code{interned-file} monadic
7403 procedure (@pxref{The Store Monad, @code{interned-file}}).
7406 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7407 Return an object representing a text file called @var{name} with the given
7408 @var{content} (a string or a bytevector) to be added to the store.
7410 This is the declarative counterpart of @code{text-file}.
7413 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7414 [#:options '(#:local-build? #t)]
7415 Return an object representing the store item @var{name}, a file or
7416 directory computed by @var{gexp}. @var{options}
7417 is a list of additional arguments to pass to @code{gexp->derivation}.
7419 This is the declarative counterpart of @code{gexp->derivation}.
7422 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7423 [#:guile (default-guile)] [#:module-path %load-path]
7424 Return an executable script @var{name} that runs @var{exp} using
7425 @var{guile}, with @var{exp}'s imported modules in its search path.
7426 Look up @var{exp}'s modules in @var{module-path}.
7428 The example below builds a script that simply invokes the @command{ls}
7432 (use-modules (guix gexp) (gnu packages base))
7434 (gexp->script "list-files"
7435 #~(execl #$(file-append coreutils "/bin/ls")
7439 When ``running'' it through the store (@pxref{The Store Monad,
7440 @code{run-with-store}}), we obtain a derivation that produces an
7441 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7444 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7446 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7450 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7451 [#:guile #f] [#:module-path %load-path]
7452 Return an object representing the executable store item @var{name} that
7453 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7454 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7456 This is the declarative counterpart of @code{gexp->script}.
7459 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7460 [#:set-load-path? #t] [#:module-path %load-path] @
7462 [#:guile (default-guile)]
7463 Return a derivation that builds a file @var{name} containing @var{exp}.
7464 When @var{splice?} is true, @var{exp} is considered to be a list of
7465 expressions that will be spliced in the resulting file.
7467 When @var{set-load-path?} is true, emit code in the resulting file to
7468 set @code{%load-path} and @code{%load-compiled-path} to honor
7469 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7472 The resulting file holds references to all the dependencies of @var{exp}
7473 or a subset thereof.
7476 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7477 Return an object representing the Scheme file @var{name} that contains
7480 This is the declarative counterpart of @code{gexp->file}.
7483 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7484 Return as a monadic value a derivation that builds a text file
7485 containing all of @var{text}. @var{text} may list, in addition to
7486 strings, objects of any type that can be used in a gexp: packages,
7487 derivations, local file objects, etc. The resulting store file holds
7488 references to all these.
7490 This variant should be preferred over @code{text-file} anytime the file
7491 to create will reference items from the store. This is typically the
7492 case when building a configuration file that embeds store file names,
7496 (define (profile.sh)
7497 ;; Return the name of a shell script in the store that
7498 ;; initializes the 'PATH' environment variable.
7499 (text-file* "profile.sh"
7500 "export PATH=" coreutils "/bin:"
7501 grep "/bin:" sed "/bin\n"))
7504 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7505 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7506 preventing them from being garbage-collected during its lifetime.
7509 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7510 Return an object representing store file @var{name} containing
7511 @var{text}. @var{text} is a sequence of strings and file-like objects,
7515 (mixed-text-file "profile"
7516 "export PATH=" coreutils "/bin:" grep "/bin")
7519 This is the declarative counterpart of @code{text-file*}.
7522 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7523 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7524 Each item in @var{files} must be a two-element list where the first element is the
7525 file name to use in the new directory, and the second element is a gexp
7526 denoting the target file. Here's an example:
7530 `(("hosts" ,(plain-file "hosts"
7531 "127.0.0.1 localhost"))
7532 ("bashrc" ,(plain-file "bashrc"
7533 "alias ls='ls --color=auto'"))))
7536 This yields an @code{etc} directory containing these two files.
7539 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7540 Return a directory that is the union of @var{things}, where @var{things} is a list of
7541 file-like objects denoting directories. For example:
7544 (directory-union "guile+emacs" (list guile emacs))
7547 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7550 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7551 Return a file-like object that expands to the concatenation of @var{obj}
7552 and @var{suffix}, where @var{obj} is a lowerable object and each
7553 @var{suffix} is a string.
7555 As an example, consider this gexp:
7558 (gexp->script "run-uname"
7559 #~(system* #$(file-append coreutils
7563 The same effect could be achieved with:
7566 (gexp->script "run-uname"
7567 #~(system* (string-append #$coreutils
7571 There is one difference though: in the @code{file-append} case, the
7572 resulting script contains the absolute file name as a string, whereas in
7573 the second case, the resulting script contains a @code{(string-append
7574 @dots{})} expression to construct the file name @emph{at run time}.
7578 Of course, in addition to gexps embedded in ``host'' code, there are
7579 also modules containing build tools. To make it clear that they are
7580 meant to be used in the build stratum, these modules are kept in the
7581 @code{(guix build @dots{})} name space.
7583 @cindex lowering, of high-level objects in gexps
7584 Internally, high-level objects are @dfn{lowered}, using their compiler,
7585 to either derivations or store items. For instance, lowering a package
7586 yields a derivation, and lowering a @code{plain-file} yields a store
7587 item. This is achieved using the @code{lower-object} monadic procedure.
7589 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7591 Return as a value in @var{%store-monad} the derivation or store item
7592 corresponding to @var{obj} for @var{system}, cross-compiling for
7593 @var{target} if @var{target} is true. @var{obj} must be an object that
7594 has an associated gexp compiler, such as a @code{<package>}.
7597 @node Invoking guix repl
7598 @section Invoking @command{guix repl}
7600 @cindex REPL, read-eval-print loop
7601 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7602 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7603 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7604 command, @command{guix repl} guarantees that all the Guix modules and all its
7605 dependencies are available in the search path. You can use it this way:
7609 scheme@@(guile-user)> ,use (gnu packages base)
7610 scheme@@(guile-user)> coreutils
7611 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7615 In addition, @command{guix repl} implements a simple machine-readable REPL
7616 protocol for use by @code{(guix inferior)}, a facility to interact with
7617 @dfn{inferiors}, separate processes running a potentially different revision
7620 The available options are as follows:
7623 @item --type=@var{type}
7624 @itemx -t @var{type}
7625 Start a REPL of the given @var{TYPE}, which can be one of the following:
7629 This is default, and it spawns a standard full-featured Guile REPL.
7631 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7632 that the @code{(guix inferior)} module speaks.
7635 @item --listen=@var{endpoint}
7636 By default, @command{guix repl} reads from standard input and writes to
7637 standard output. When this option is passed, it will instead listen for
7638 connections on @var{endpoint}. Here are examples of valid options:
7641 @item --listen=tcp:37146
7642 Accept connections on localhost on port 37146.
7644 @item --listen=unix:/tmp/socket
7645 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7649 @c *********************************************************************
7653 This section describes Guix command-line utilities. Some of them are
7654 primarily targeted at developers and users who write new package
7655 definitions, while others are more generally useful. They complement
7656 the Scheme programming interface of Guix in a convenient way.
7659 * Invoking guix build:: Building packages from the command line.
7660 * Invoking guix edit:: Editing package definitions.
7661 * Invoking guix download:: Downloading a file and printing its hash.
7662 * Invoking guix hash:: Computing the cryptographic hash of a file.
7663 * Invoking guix import:: Importing package definitions.
7664 * Invoking guix refresh:: Updating package definitions.
7665 * Invoking guix lint:: Finding errors in package definitions.
7666 * Invoking guix size:: Profiling disk usage.
7667 * Invoking guix graph:: Visualizing the graph of packages.
7668 * Invoking guix publish:: Sharing substitutes.
7669 * Invoking guix challenge:: Challenging substitute servers.
7670 * Invoking guix copy:: Copying to and from a remote store.
7671 * Invoking guix container:: Process isolation.
7672 * Invoking guix weather:: Assessing substitute availability.
7673 * Invoking guix processes:: Listing client processes.
7676 @node Invoking guix build
7677 @section Invoking @command{guix build}
7679 @cindex package building
7680 @cindex @command{guix build}
7681 The @command{guix build} command builds packages or derivations and
7682 their dependencies, and prints the resulting store paths. Note that it
7683 does not modify the user's profile---this is the job of the
7684 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7685 it is mainly useful for distribution developers.
7687 The general syntax is:
7690 guix build @var{options} @var{package-or-derivation}@dots{}
7693 As an example, the following command builds the latest versions of Emacs
7694 and of Guile, displays their build logs, and finally displays the
7695 resulting directories:
7698 guix build emacs guile
7701 Similarly, the following command builds all the available packages:
7704 guix build --quiet --keep-going \
7705 `guix package -A | cut -f1,2 --output-delimiter=@@`
7708 @var{package-or-derivation} may be either the name of a package found in
7709 the software distribution such as @code{coreutils} or
7710 @code{coreutils@@8.20}, or a derivation such as
7711 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7712 package with the corresponding name (and optionally version) is searched
7713 for among the GNU distribution modules (@pxref{Package Modules}).
7715 Alternatively, the @code{--expression} option may be used to specify a
7716 Scheme expression that evaluates to a package; this is useful when
7717 disambiguating among several same-named packages or package variants is
7720 There may be zero or more @var{options}. The available options are
7721 described in the subsections below.
7724 * Common Build Options:: Build options for most commands.
7725 * Package Transformation Options:: Creating variants of packages.
7726 * Additional Build Options:: Options specific to 'guix build'.
7727 * Debugging Build Failures:: Real life packaging experience.
7730 @node Common Build Options
7731 @subsection Common Build Options
7733 A number of options that control the build process are common to
7734 @command{guix build} and other commands that can spawn builds, such as
7735 @command{guix package} or @command{guix archive}. These are the
7740 @item --load-path=@var{directory}
7741 @itemx -L @var{directory}
7742 Add @var{directory} to the front of the package module search path
7743 (@pxref{Package Modules}).
7745 This allows users to define their own packages and make them visible to
7746 the command-line tools.
7750 Keep the build tree of failed builds. Thus, if a build fails, its build
7751 tree is kept under @file{/tmp}, in a directory whose name is shown at
7752 the end of the build log. This is useful when debugging build issues.
7753 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7756 This option has no effect when connecting to a remote daemon with a
7757 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7762 Keep going when some of the derivations fail to build; return only once
7763 all the builds have either completed or failed.
7765 The default behavior is to stop as soon as one of the specified
7766 derivations has failed.
7770 Do not build the derivations.
7772 @anchor{fallback-option}
7774 When substituting a pre-built binary fails, fall back to building
7775 packages locally (@pxref{Substitution Failure}).
7777 @item --substitute-urls=@var{urls}
7778 @anchor{client-substitute-urls}
7779 Consider @var{urls} the whitespace-separated list of substitute source
7780 URLs, overriding the default list of URLs of @command{guix-daemon}
7781 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7783 This means that substitutes may be downloaded from @var{urls}, provided
7784 they are signed by a key authorized by the system administrator
7785 (@pxref{Substitutes}).
7787 When @var{urls} is the empty string, substitutes are effectively
7790 @item --no-substitutes
7791 Do not use substitutes for build products. That is, always build things
7792 locally instead of allowing downloads of pre-built binaries
7793 (@pxref{Substitutes}).
7796 Do not ``graft'' packages. In practice, this means that package updates
7797 available as grafts are not applied. @xref{Security Updates}, for more
7798 information on grafts.
7800 @item --rounds=@var{n}
7801 Build each derivation @var{n} times in a row, and raise an error if
7802 consecutive build results are not bit-for-bit identical.
7804 This is a useful way to detect non-deterministic builds processes.
7805 Non-deterministic build processes are a problem because they make it
7806 practically impossible for users to @emph{verify} whether third-party
7807 binaries are genuine. @xref{Invoking guix challenge}, for more.
7809 Note that, currently, the differing build results are not kept around,
7810 so you will have to manually investigate in case of an error---e.g., by
7811 stashing one of the build results with @code{guix archive --export}
7812 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7815 @item --no-build-hook
7816 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7817 (@pxref{Daemon Offload Setup}). That is, always build things locally
7818 instead of offloading builds to remote machines.
7820 @item --max-silent-time=@var{seconds}
7821 When the build or substitution process remains silent for more than
7822 @var{seconds}, terminate it and report a build failure.
7824 By default, the daemon's setting is honored (@pxref{Invoking
7825 guix-daemon, @code{--max-silent-time}}).
7827 @item --timeout=@var{seconds}
7828 Likewise, when the build or substitution process lasts for more than
7829 @var{seconds}, terminate it and report a build failure.
7831 By default, the daemon's setting is honored (@pxref{Invoking
7832 guix-daemon, @code{--timeout}}).
7834 @c Note: This option is actually not part of %standard-build-options but
7835 @c most programs honor it.
7836 @cindex verbosity, of the command-line tools
7837 @cindex build logs, verbosity
7838 @item -v @var{level}
7839 @itemx --verbosity=@var{level}
7840 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7841 output is produced, 1 is for quiet output, and 2 shows all the build log
7842 output on standard error.
7844 @item --cores=@var{n}
7846 Allow the use of up to @var{n} CPU cores for the build. The special
7847 value @code{0} means to use as many CPU cores as available.
7849 @item --max-jobs=@var{n}
7851 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7852 guix-daemon, @code{--max-jobs}}, for details about this option and the
7853 equivalent @command{guix-daemon} option.
7855 @item --debug=@var{level}
7856 Produce debugging output coming from the build daemon. @var{level} must be an
7857 integer between 0 and 5; higher means more verbose output. Setting a level of
7858 4 or more may be helpful when debugging setup issues with the build daemon.
7862 Behind the scenes, @command{guix build} is essentially an interface to
7863 the @code{package-derivation} procedure of the @code{(guix packages)}
7864 module, and to the @code{build-derivations} procedure of the @code{(guix
7865 derivations)} module.
7867 In addition to options explicitly passed on the command line,
7868 @command{guix build} and other @command{guix} commands that support
7869 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7871 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7872 Users can define this variable to a list of command line options that
7873 will automatically be used by @command{guix build} and other
7874 @command{guix} commands that can perform builds, as in the example
7878 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7881 These options are parsed independently, and the result is appended to
7882 the parsed command-line options.
7886 @node Package Transformation Options
7887 @subsection Package Transformation Options
7889 @cindex package variants
7890 Another set of command-line options supported by @command{guix build}
7891 and also @command{guix package} are @dfn{package transformation
7892 options}. These are options that make it possible to define @dfn{package
7893 variants}---for instance, packages built from different source code.
7894 This is a convenient way to create customized packages on the fly
7895 without having to type in the definitions of package variants
7896 (@pxref{Defining Packages}).
7900 @item --with-source=@var{source}
7901 @itemx --with-source=@var{package}=@var{source}
7902 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7903 Use @var{source} as the source of @var{package}, and @var{version} as
7905 @var{source} must be a file name or a URL, as for @command{guix
7906 download} (@pxref{Invoking guix download}).
7908 When @var{package} is omitted,
7909 it is taken to be the package name specified on the
7910 command line that matches the base of @var{source}---e.g.,
7911 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7912 package is @code{guile}.
7914 Likewise, when @var{version} is omitted, the version string is inferred from
7915 @var{source}; in the previous example, it is @code{2.0.10}.
7917 This option allows users to try out versions of packages other than the
7918 one provided by the distribution. The example below downloads
7919 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7920 the @code{ed} package:
7923 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7926 As a developer, @code{--with-source} makes it easy to test release
7930 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7933 @dots{} or to build from a checkout in a pristine environment:
7936 $ git clone git://git.sv.gnu.org/guix.git
7937 $ guix build guix --with-source=guix@@1.0=./guix
7940 @item --with-input=@var{package}=@var{replacement}
7941 Replace dependency on @var{package} by a dependency on
7942 @var{replacement}. @var{package} must be a package name, and
7943 @var{replacement} must be a package specification such as @code{guile}
7944 or @code{guile@@1.8}.
7946 For instance, the following command builds Guix, but replaces its
7947 dependency on the current stable version of Guile with a dependency on
7948 the legacy version of Guile, @code{guile@@2.0}:
7951 guix build --with-input=guile=guile@@2.0 guix
7954 This is a recursive, deep replacement. So in this example, both
7955 @code{guix} and its dependency @code{guile-json} (which also depends on
7956 @code{guile}) get rebuilt against @code{guile@@2.0}.
7958 This is implemented using the @code{package-input-rewriting} Scheme
7959 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7961 @item --with-graft=@var{package}=@var{replacement}
7962 This is similar to @code{--with-input} but with an important difference:
7963 instead of rebuilding the whole dependency chain, @var{replacement} is
7964 built and then @dfn{grafted} onto the binaries that were initially
7965 referring to @var{package}. @xref{Security Updates}, for more
7966 information on grafts.
7968 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7969 and all its dependencies, replacing references to the version of GnuTLS
7970 they currently refer to:
7973 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7976 This has the advantage of being much faster than rebuilding everything.
7977 But there is a caveat: it works if and only if @var{package} and
7978 @var{replacement} are strictly compatible---for example, if they provide
7979 a library, the application binary interface (ABI) of those libraries
7980 must be compatible. If @var{replacement} is somehow incompatible with
7981 @var{package}, then the resulting package may be unusable. Use with
7984 @item --with-git-url=@var{package}=@var{url}
7985 @cindex Git, using the latest commit
7986 @cindex latest commit, building
7987 Build @var{package} from the latest commit of the @code{master} branch of the
7988 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7991 For example, the following command builds the NumPy Python library against the
7992 latest commit of the master branch of Python itself:
7995 guix build python-numpy \
7996 --with-git-url=python=https://github.com/python/cpython
7999 This option can also be combined with @code{--with-branch} or
8000 @code{--with-commit} (see below).
8002 @cindex continuous integration
8003 Obviously, since it uses the latest commit of the given branch, the result of
8004 such a command varies over time. Nevertheless it is a convenient way to
8005 rebuild entire software stacks against the latest commit of one or more
8006 packages. This is particularly useful in the context of continuous
8009 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8010 consecutive accesses to the same repository. You may want to clean it up once
8011 in a while to save disk space.
8013 @item --with-branch=@var{package}=@var{branch}
8014 Build @var{package} from the latest commit of @var{branch}. If the
8015 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8016 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8017 repository URL is taken from that @code{source}. Otherwise you have to use
8018 @code{--with-git-url} to specify the URL of the Git repository.
8020 For instance, the following command builds @code{guile-sqlite3} from the
8021 latest commit of its @code{master} branch, and then builds @code{guix} (which
8022 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8023 specific @code{guile-sqlite3} build:
8026 guix build --with-branch=guile-sqlite3=master cuirass
8029 @item --with-commit=@var{package}=@var{commit}
8030 This is similar to @code{--with-branch}, except that it builds from
8031 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8032 Git commit SHA1 identifier.
8035 @node Additional Build Options
8036 @subsection Additional Build Options
8038 The command-line options presented below are specific to @command{guix
8045 Build quietly, without displaying the build log; this is equivalent to
8046 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8047 (or similar) and can always be retrieved using the @option{--log-file} option.
8049 @item --file=@var{file}
8050 @itemx -f @var{file}
8051 Build the package, derivation, or other file-like object that the code within
8052 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8054 As an example, @var{file} might contain a package definition like this
8055 (@pxref{Defining Packages}):
8058 @verbatiminclude package-hello.scm
8061 @item --expression=@var{expr}
8062 @itemx -e @var{expr}
8063 Build the package or derivation @var{expr} evaluates to.
8065 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8066 guile-1.8)}, which unambiguously designates this specific variant of
8067 version 1.8 of Guile.
8069 Alternatively, @var{expr} may be a G-expression, in which case it is used
8070 as a build program passed to @code{gexp->derivation}
8071 (@pxref{G-Expressions}).
8073 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8074 (@pxref{The Store Monad}). The procedure must return a derivation as a
8075 monadic value, which is then passed through @code{run-with-store}.
8079 Build the source derivations of the packages, rather than the packages
8082 For instance, @code{guix build -S gcc} returns something like
8083 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8086 The returned source tarball is the result of applying any patches and
8087 code snippets specified in the package @code{origin} (@pxref{Defining
8091 Fetch and return the source of @var{package-or-derivation} and all their
8092 dependencies, recursively. This is a handy way to obtain a local copy
8093 of all the source code needed to build @var{packages}, allowing you to
8094 eventually build them even without network access. It is an extension
8095 of the @code{--source} option and can accept one of the following
8096 optional argument values:
8100 This value causes the @code{--sources} option to behave in the same way
8101 as the @code{--source} option.
8104 Build the source derivations of all packages, including any source that
8105 might be listed as @code{inputs}. This is the default value.
8108 $ guix build --sources tzdata
8109 The following derivations will be built:
8110 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8111 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8115 Build the source derivations of all packages, as well of all transitive
8116 inputs to the packages. This can be used e.g.@: to
8117 prefetch package source for later offline building.
8120 $ guix build --sources=transitive tzdata
8121 The following derivations will be built:
8122 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8123 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8124 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8125 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8126 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8127 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8133 @item --system=@var{system}
8134 @itemx -s @var{system}
8135 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8136 the system type of the build host. The @command{guix build} command allows
8137 you to repeat this option several times, in which case it builds for all the
8138 specified systems; other commands ignore extraneous @option{-s} options.
8141 The @code{--system} flag is for @emph{native} compilation and must not
8142 be confused with cross-compilation. See @code{--target} below for
8143 information on cross-compilation.
8146 An example use of this is on Linux-based systems, which can emulate
8147 different personalities. For instance, passing
8148 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8149 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8150 to build packages in a complete 32-bit environment.
8153 Building for an @code{armhf-linux} system is unconditionally enabled on
8154 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8155 allow for this functionality, notably the ThunderX.
8158 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8159 is enabled (@pxref{Virtualization Services,
8160 @code{qemu-binfmt-service-type}}), you can build for any system for
8161 which a QEMU @code{binfmt_misc} handler is installed.
8163 Builds for a system other than that of the machine you are using can
8164 also be offloaded to a remote machine of the right architecture.
8165 @xref{Daemon Offload Setup}, for more information on offloading.
8167 @item --target=@var{triplet}
8168 @cindex cross-compilation
8169 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8170 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8171 configuration triplets,, autoconf, Autoconf}).
8173 @anchor{build-check}
8175 @cindex determinism, checking
8176 @cindex reproducibility, checking
8177 Rebuild @var{package-or-derivation}, which are already available in the
8178 store, and raise an error if the build results are not bit-for-bit
8181 This mechanism allows you to check whether previously installed
8182 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8183 of a package is deterministic. @xref{Invoking guix challenge}, for more
8184 background information and tools.
8186 When used in conjunction with @option{--keep-failed}, the differing
8187 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8188 This makes it easy to look for differences between the two results.
8191 @cindex repairing store items
8192 @cindex corruption, recovering from
8193 Attempt to repair the specified store items, if they are corrupt, by
8194 re-downloading or rebuilding them.
8196 This operation is not atomic and thus restricted to @code{root}.
8200 Return the derivation paths, not the output paths, of the given
8203 @item --root=@var{file}
8204 @itemx -r @var{file}
8205 @cindex GC roots, adding
8206 @cindex garbage collector roots, adding
8207 Make @var{file} a symlink to the result, and register it as a garbage
8210 Consequently, the results of this @command{guix build} invocation are
8211 protected from garbage collection until @var{file} is removed. When
8212 that option is omitted, build results are eligible for garbage
8213 collection as soon as the build completes. @xref{Invoking guix gc}, for
8217 @cindex build logs, access
8218 Return the build log file names or URLs for the given
8219 @var{package-or-derivation}, or raise an error if build logs are
8222 This works regardless of how packages or derivations are specified. For
8223 instance, the following invocations are equivalent:
8226 guix build --log-file `guix build -d guile`
8227 guix build --log-file `guix build guile`
8228 guix build --log-file guile
8229 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8232 If a log is unavailable locally, and unless @code{--no-substitutes} is
8233 passed, the command looks for a corresponding log on one of the
8234 substitute servers (as specified with @code{--substitute-urls}.)
8236 So for instance, imagine you want to see the build log of GDB on MIPS,
8237 but you are actually on an @code{x86_64} machine:
8240 $ guix build --log-file gdb -s mips64el-linux
8241 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8244 You can freely access a huge library of build logs!
8247 @node Debugging Build Failures
8248 @subsection Debugging Build Failures
8250 @cindex build failures, debugging
8251 When defining a new package (@pxref{Defining Packages}), you will
8252 probably find yourself spending some time debugging and tweaking the
8253 build until it succeeds. To do that, you need to operate the build
8254 commands yourself in an environment as close as possible to the one the
8257 To that end, the first thing to do is to use the @option{--keep-failed}
8258 or @option{-K} option of @command{guix build}, which will keep the
8259 failed build tree in @file{/tmp} or whatever directory you specified as
8260 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8262 From there on, you can @command{cd} to the failed build tree and source
8263 the @file{environment-variables} file, which contains all the
8264 environment variable definitions that were in place when the build
8265 failed. So let's say you're debugging a build failure in package
8266 @code{foo}; a typical session would look like this:
8270 @dots{} @i{build fails}
8271 $ cd /tmp/guix-build-foo.drv-0
8272 $ source ./environment-variables
8276 Now, you can invoke commands as if you were the daemon (almost) and
8277 troubleshoot your build process.
8279 Sometimes it happens that, for example, a package's tests pass when you
8280 run them manually but they fail when the daemon runs them. This can
8281 happen because the daemon runs builds in containers where, unlike in our
8282 environment above, network access is missing, @file{/bin/sh} does not
8283 exist, etc. (@pxref{Build Environment Setup}).
8285 In such cases, you may need to run inspect the build process from within
8286 a container similar to the one the build daemon creates:
8291 $ cd /tmp/guix-build-foo.drv-0
8292 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8293 [env]# source ./environment-variables
8297 Here, @command{guix environment -C} creates a container and spawns a new
8298 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8299 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8300 the container, which would may find handy while debugging. The
8301 @option{--no-grafts} option makes sure we get the exact same
8302 environment, with ungrafted packages (@pxref{Security Updates}, for more
8305 To get closer to a container like that used by the build daemon, we can
8306 remove @file{/bin/sh}:
8312 (Don't worry, this is harmless: this is all happening in the throw-away
8313 container created by @command{guix environment}.)
8315 The @command{strace} command is probably not in the search path, but we
8319 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8322 In this way, not only you will have reproduced the environment variables
8323 the daemon uses, you will also be running the build process in a container
8324 similar to the one the daemon uses.
8327 @node Invoking guix edit
8328 @section Invoking @command{guix edit}
8330 @cindex @command{guix edit}
8331 @cindex package definition, editing
8332 So many packages, so many source files! The @command{guix edit} command
8333 facilitates the life of users and packagers by pointing their editor at
8334 the source file containing the definition of the specified packages.
8338 guix edit gcc@@4.9 vim
8342 launches the program specified in the @code{VISUAL} or in the
8343 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8346 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8347 have created your own packages on @code{GUIX_PACKAGE_PATH}
8348 (@pxref{Package Modules}), you will be able to edit the package
8349 recipes. In other cases, you will be able to examine the read-only recipes
8350 for packages currently in the store.
8353 @node Invoking guix download
8354 @section Invoking @command{guix download}
8356 @cindex @command{guix download}
8357 @cindex downloading package sources
8358 When writing a package definition, developers typically need to download
8359 a source tarball, compute its SHA256 hash, and write that
8360 hash in the package definition (@pxref{Defining Packages}). The
8361 @command{guix download} tool helps with this task: it downloads a file
8362 from the given URI, adds it to the store, and prints both its file name
8363 in the store and its SHA256 hash.
8365 The fact that the downloaded file is added to the store saves bandwidth:
8366 when the developer eventually tries to build the newly defined package
8367 with @command{guix build}, the source tarball will not have to be
8368 downloaded again because it is already in the store. It is also a
8369 convenient way to temporarily stash files, which may be deleted
8370 eventually (@pxref{Invoking guix gc}).
8372 The @command{guix download} command supports the same URIs as used in
8373 package definitions. In particular, it supports @code{mirror://} URIs.
8374 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8375 Guile bindings for GnuTLS are available in the user's environment; when
8376 they are not available, an error is raised. @xref{Guile Preparations,
8377 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8378 GnuTLS-Guile}, for more information.
8380 @command{guix download} verifies HTTPS server certificates by loading
8381 the certificates of X.509 authorities from the directory pointed to by
8382 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8383 Certificates}), unless @option{--no-check-certificate} is used.
8385 The following options are available:
8388 @item --format=@var{fmt}
8390 Write the hash in the format specified by @var{fmt}. For more
8391 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8393 @item --no-check-certificate
8394 Do not validate the X.509 certificates of HTTPS servers.
8396 When using this option, you have @emph{absolutely no guarantee} that you
8397 are communicating with the authentic server responsible for the given
8398 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8400 @item --output=@var{file}
8401 @itemx -o @var{file}
8402 Save the downloaded file to @var{file} instead of adding it to the
8406 @node Invoking guix hash
8407 @section Invoking @command{guix hash}
8409 @cindex @command{guix hash}
8410 The @command{guix hash} command computes the SHA256 hash of a file.
8411 It is primarily a convenience tool for anyone contributing to the
8412 distribution: it computes the cryptographic hash of a file, which can be
8413 used in the definition of a package (@pxref{Defining Packages}).
8415 The general syntax is:
8418 guix hash @var{option} @var{file}
8421 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8422 hash of data read from standard input. @command{guix hash} has the
8427 @item --format=@var{fmt}
8429 Write the hash in the format specified by @var{fmt}.
8431 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8432 (@code{hex} and @code{hexadecimal} can be used as well).
8434 If the @option{--format} option is not specified, @command{guix hash}
8435 will output the hash in @code{nix-base32}. This representation is used
8436 in the definitions of packages.
8440 Compute the hash on @var{file} recursively.
8442 In this case, the hash is computed on an archive containing @var{file},
8443 including its children if it is a directory. Some of the metadata of
8444 @var{file} is part of the archive; for instance, when @var{file} is a
8445 regular file, the hash is different depending on whether @var{file} is
8446 executable or not. Metadata such as time stamps has no impact on the
8447 hash (@pxref{Invoking guix archive}).
8448 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8453 When combined with @option{--recursive}, exclude version control system
8454 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8457 As an example, here is how you would compute the hash of a Git checkout,
8458 which is useful when using the @code{git-fetch} method (@pxref{origin
8462 $ git clone http://example.org/foo.git
8468 @node Invoking guix import
8469 @section Invoking @command{guix import}
8471 @cindex importing packages
8472 @cindex package import
8473 @cindex package conversion
8474 @cindex Invoking @command{guix import}
8475 The @command{guix import} command is useful for people who would like to
8476 add a package to the distribution with as little work as
8477 possible---a legitimate demand. The command knows of a few
8478 repositories from which it can ``import'' package metadata. The result
8479 is a package definition, or a template thereof, in the format we know
8480 (@pxref{Defining Packages}).
8482 The general syntax is:
8485 guix import @var{importer} @var{options}@dots{}
8488 @var{importer} specifies the source from which to import package
8489 metadata, and @var{options} specifies a package identifier and other
8490 options specific to @var{importer}. Currently, the available
8495 Import metadata for the given GNU package. This provides a template
8496 for the latest version of that GNU package, including the hash of its
8497 source tarball, and its canonical synopsis and description.
8499 Additional information such as the package dependencies and its
8500 license needs to be figured out manually.
8502 For example, the following command returns a package definition for
8506 guix import gnu hello
8509 Specific command-line options are:
8512 @item --key-download=@var{policy}
8513 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8514 keys when verifying the package signature. @xref{Invoking guix
8515 refresh, @code{--key-download}}.
8520 Import metadata from the @uref{https://pypi.python.org/, Python Package
8521 Index}. Information is taken from the JSON-formatted description
8522 available at @code{pypi.python.org} and usually includes all the relevant
8523 information, including package dependencies. For maximum efficiency, it
8524 is recommended to install the @command{unzip} utility, so that the
8525 importer can unzip Python wheels and gather data from them.
8527 The command below imports metadata for the @code{itsdangerous} Python
8531 guix import pypi itsdangerous
8537 Traverse the dependency graph of the given upstream package recursively
8538 and generate package expressions for all those packages that are not yet
8544 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8545 is taken from the JSON-formatted description available at
8546 @code{rubygems.org} and includes most relevant information, including
8547 runtime dependencies. There are some caveats, however. The metadata
8548 doesn't distinguish between synopses and descriptions, so the same string
8549 is used for both fields. Additionally, the details of non-Ruby
8550 dependencies required to build native extensions is unavailable and left
8551 as an exercise to the packager.
8553 The command below imports metadata for the @code{rails} Ruby package:
8556 guix import gem rails
8562 Traverse the dependency graph of the given upstream package recursively
8563 and generate package expressions for all those packages that are not yet
8569 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8570 Information is taken from the JSON-formatted metadata provided through
8571 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8572 relevant information, such as module dependencies. License information
8573 should be checked closely. If Perl is available in the store, then the
8574 @code{corelist} utility will be used to filter core modules out of the
8575 list of dependencies.
8577 The command command below imports metadata for the @code{Acme::Boolean}
8581 guix import cpan Acme::Boolean
8586 @cindex Bioconductor
8587 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8588 central repository for the @uref{https://r-project.org, GNU@tie{}R
8589 statistical and graphical environment}.
8591 Information is extracted from the @code{DESCRIPTION} file of the package.
8593 The command command below imports metadata for the @code{Cairo}
8597 guix import cran Cairo
8600 When @code{--recursive} is added, the importer will traverse the
8601 dependency graph of the given upstream package recursively and generate
8602 package expressions for all those packages that are not yet in Guix.
8604 When @code{--archive=bioconductor} is added, metadata is imported from
8605 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8606 packages for for the analysis and comprehension of high-throughput
8607 genomic data in bioinformatics.
8609 Information is extracted from the @code{DESCRIPTION} file of a package
8610 published on the web interface of the Bioconductor SVN repository.
8612 The command below imports metadata for the @code{GenomicRanges}
8616 guix import cran --archive=bioconductor GenomicRanges
8622 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8623 comprehensive TeX archive network for TeX packages that are part of the
8624 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8626 Information about the package is obtained through the XML API provided
8627 by CTAN, while the source code is downloaded from the SVN repository of
8628 the Tex Live project. This is done because the CTAN does not keep
8631 The command command below imports metadata for the @code{fontspec}
8635 guix import texlive fontspec
8638 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8639 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8640 tree in the TeX Live SVN repository, but from the specified sibling
8641 directory under the same root.
8643 The command below imports metadata for the @code{ifxetex} package from
8644 CTAN while fetching the sources from the directory
8645 @file{texmf/source/generic}:
8648 guix import texlive --archive=generic ifxetex
8652 @cindex JSON, import
8653 Import package metadata from a local JSON file. Consider the following
8654 example package definition in JSON format:
8660 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8661 "build-system": "gnu",
8662 "home-page": "https://www.gnu.org/software/hello/",
8663 "synopsis": "Hello, GNU world: An example GNU package",
8664 "description": "GNU Hello prints a greeting.",
8665 "license": "GPL-3.0+",
8666 "native-inputs": ["gcc@@6"]
8670 The field names are the same as for the @code{<package>} record
8671 (@xref{Defining Packages}). References to other packages are provided
8672 as JSON lists of quoted package specification strings such as
8673 @code{guile} or @code{guile@@2.0}.
8675 The importer also supports a more explicit source definition using the
8676 common fields for @code{<origin>} records:
8682 "method": "url-fetch",
8683 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8685 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8692 The command below reads metadata from the JSON file @code{hello.json}
8693 and outputs a package expression:
8696 guix import json hello.json
8700 Import metadata from a local copy of the source of the
8701 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8702 relies on the @command{nix-instantiate} command of
8703 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8704 typically written in a mixture of Nix-language and Bash code. This
8705 command only imports the high-level package structure that is written in
8706 the Nix language. It normally includes all the basic fields of a
8709 When importing a GNU package, the synopsis and descriptions are replaced
8710 by their canonical upstream variant.
8712 Usually, you will first need to do:
8715 export NIX_REMOTE=daemon
8719 so that @command{nix-instantiate} does not try to open the Nix database.
8721 As an example, the command below imports the package definition of
8722 LibreOffice (more precisely, it imports the definition of the package
8723 bound to the @code{libreoffice} top-level attribute):
8726 guix import nix ~/path/to/nixpkgs libreoffice
8731 Import metadata from the Haskell community's central package archive
8732 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8733 Cabal files and includes all the relevant information, including package
8736 Specific command-line options are:
8741 Read a Cabal file from standard input.
8742 @item --no-test-dependencies
8744 Do not include dependencies required only by the test suites.
8745 @item --cabal-environment=@var{alist}
8746 @itemx -e @var{alist}
8747 @var{alist} is a Scheme alist defining the environment in which the
8748 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8749 @code{arch}, @code{impl} and a string representing the name of a flag.
8750 The value associated with a flag has to be either the symbol
8751 @code{true} or @code{false}. The value associated with other keys
8752 has to conform to the Cabal file format definition. The default value
8753 associated with the keys @code{os}, @code{arch} and @code{impl} is
8754 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8757 Traverse the dependency graph of the given upstream package recursively
8758 and generate package expressions for all those packages that are not yet
8762 The command below imports metadata for the latest version of the
8763 @code{HTTP} Haskell package without including test dependencies and
8764 specifying the value of the flag @samp{network-uri} as @code{false}:
8767 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8770 A specific package version may optionally be specified by following the
8771 package name by an at-sign and a version number as in the following example:
8774 guix import hackage mtl@@2.1.3.1
8779 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8780 It takes a package name, looks up the package version included in a
8781 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8782 release and uses the @code{hackage} importer to retrieve its metadata.
8783 Note that it is up to you to select an LTS release compatible with the
8784 GHC compiler used by Guix.
8786 Specific command-line options are:
8789 @item --no-test-dependencies
8791 Do not include dependencies required only by the test suites.
8792 @item --lts-version=@var{version}
8793 @itemx -l @var{version}
8794 @var{version} is the desired LTS release version. If omitted the latest
8798 Traverse the dependency graph of the given upstream package recursively
8799 and generate package expressions for all those packages that are not yet
8803 The command below imports metadata for the @code{HTTP} Haskell package
8804 included in the LTS Stackage release version 7.18:
8807 guix import stackage --lts-version=7.18 HTTP
8812 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8813 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8815 Specific command-line options are:
8818 @item --archive=@var{repo}
8819 @itemx -a @var{repo}
8820 @var{repo} identifies the archive repository from which to retrieve the
8821 information. Currently the supported repositories and their identifiers
8825 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8826 identifier. This is the default.
8828 Packages from @code{elpa.gnu.org} are signed with one of the keys
8829 contained in the GnuPG keyring at
8830 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8831 @code{emacs} package (@pxref{Package Installation, ELPA package
8832 signatures,, emacs, The GNU Emacs Manual}).
8835 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
8836 @code{melpa-stable} identifier.
8839 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
8845 Traverse the dependency graph of the given upstream package recursively
8846 and generate package expressions for all those packages that are not yet
8852 Import metadata from the crates.io Rust package repository
8853 @uref{https://crates.io, crates.io}.
8858 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8859 repository used by the OCaml community.
8862 The structure of the @command{guix import} code is modular. It would be
8863 useful to have more importers for other package formats, and your help
8864 is welcome here (@pxref{Contributing}).
8866 @node Invoking guix refresh
8867 @section Invoking @command{guix refresh}
8869 @cindex @command {guix refresh}
8870 The primary audience of the @command{guix refresh} command is developers
8871 of the GNU software distribution. By default, it reports any packages
8872 provided by the distribution that are outdated compared to the latest
8873 upstream version, like this:
8877 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8878 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8881 Alternately, one can specify packages to consider, in which case a
8882 warning is emitted for packages that lack an updater:
8885 $ guix refresh coreutils guile guile-ssh
8886 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8887 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8890 @command{guix refresh} browses the upstream repository of each package and determines
8891 the highest version number of the releases therein. The command
8892 knows how to update specific types of packages: GNU packages, ELPA
8893 packages, etc.---see the documentation for @option{--type} below. There
8894 are many packages, though, for which it lacks a method to determine
8895 whether a new upstream release is available. However, the mechanism is
8896 extensible, so feel free to get in touch with us to add a new method!
8901 Consider the packages specified, and all the packages upon which they depend.
8904 $ guix refresh --recursive coreutils
8905 gnu/packages/acl.scm:35:2: warning: no updater for acl
8906 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8907 gnu/packages/xml.scm:68:2: warning: no updater for expat
8908 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8914 Sometimes the upstream name differs from the package name used in Guix,
8915 and @command{guix refresh} needs a little help. Most updaters honor the
8916 @code{upstream-name} property in package definitions, which can be used
8920 (define-public network-manager
8922 (name "network-manager")
8924 (properties '((upstream-name . "NetworkManager")))))
8927 When passed @code{--update}, it modifies distribution source files to
8928 update the version numbers and source tarball hashes of those package
8929 recipes (@pxref{Defining Packages}). This is achieved by downloading
8930 each package's latest source tarball and its associated OpenPGP
8931 signature, authenticating the downloaded tarball against its signature
8932 using @command{gpg}, and finally computing its hash. When the public
8933 key used to sign the tarball is missing from the user's keyring, an
8934 attempt is made to automatically retrieve it from a public key server;
8935 when this is successful, the key is added to the user's keyring; otherwise,
8936 @command{guix refresh} reports an error.
8938 The following options are supported:
8942 @item --expression=@var{expr}
8943 @itemx -e @var{expr}
8944 Consider the package @var{expr} evaluates to.
8946 This is useful to precisely refer to a package, as in this example:
8949 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8952 This command lists the dependents of the ``final'' libc (essentially all
8957 Update distribution source files (package recipes) in place. This is
8958 usually run from a checkout of the Guix source tree (@pxref{Running
8959 Guix Before It Is Installed}):
8962 $ ./pre-inst-env guix refresh -s non-core -u
8965 @xref{Defining Packages}, for more information on package definitions.
8967 @item --select=[@var{subset}]
8968 @itemx -s @var{subset}
8969 Select all the packages in @var{subset}, one of @code{core} or
8972 The @code{core} subset refers to all the packages at the core of the
8973 distribution---i.e., packages that are used to build ``everything
8974 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8975 changing one of these packages in the distribution entails a rebuild of
8976 all the others. Thus, such updates are an inconvenience to users in
8977 terms of build time or bandwidth used to achieve the upgrade.
8979 The @code{non-core} subset refers to the remaining packages. It is
8980 typically useful in cases where an update of the core packages would be
8983 @item --manifest=@var{file}
8984 @itemx -m @var{file}
8985 Select all the packages from the manifest in @var{file}. This is useful to
8986 check if any packages of the user manifest can be updated.
8988 @item --type=@var{updater}
8989 @itemx -t @var{updater}
8990 Select only packages handled by @var{updater} (may be a comma-separated
8991 list of updaters). Currently, @var{updater} may be one of:
8995 the updater for GNU packages;
8997 the updater for GNOME packages;
8999 the updater for KDE packages;
9001 the updater for X.org packages;
9003 the updater for packages hosted on kernel.org;
9005 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9007 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9009 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9011 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9013 the updater for @uref{https://pypi.python.org, PyPI} packages.
9015 the updater for @uref{https://rubygems.org, RubyGems} packages.
9017 the updater for @uref{https://github.com, GitHub} packages.
9019 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9021 the updater for @uref{https://www.stackage.org, Stackage} packages.
9023 the updater for @uref{https://crates.io, Crates} packages.
9025 the updater for @uref{https://launchpad.net, Launchpad} packages.
9028 For instance, the following command only checks for updates of Emacs
9029 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9032 $ guix refresh --type=elpa,cran
9033 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9034 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9039 In addition, @command{guix refresh} can be passed one or more package
9040 names, as in this example:
9043 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9047 The command above specifically updates the @code{emacs} and
9048 @code{idutils} packages. The @code{--select} option would have no
9049 effect in this case.
9051 When considering whether to upgrade a package, it is sometimes
9052 convenient to know which packages would be affected by the upgrade and
9053 should be checked for compatibility. For this the following option may
9054 be used when passing @command{guix refresh} one or more package names:
9058 @item --list-updaters
9060 List available updaters and exit (see @option{--type} above.)
9062 For each updater, display the fraction of packages it covers; at the
9063 end, display the fraction of packages covered by all these updaters.
9065 @item --list-dependent
9067 List top-level dependent packages that would need to be rebuilt as a
9068 result of upgrading one or more packages.
9070 @xref{Invoking guix graph, the @code{reverse-package} type of
9071 @command{guix graph}}, for information on how to visualize the list of
9072 dependents of a package.
9076 Be aware that the @code{--list-dependent} option only
9077 @emph{approximates} the rebuilds that would be required as a result of
9078 an upgrade. More rebuilds might be required under some circumstances.
9081 $ guix refresh --list-dependent flex
9082 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9083 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9086 The command above lists a set of packages that could be built to check
9087 for compatibility with an upgraded @code{flex} package.
9091 @item --list-transitive
9092 List all the packages which one or more packages depend upon.
9095 $ guix refresh --list-transitive flex
9096 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9097 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{}
9102 The command above lists a set of packages which, when changed, would cause
9103 @code{flex} to be rebuilt.
9105 The following options can be used to customize GnuPG operation:
9109 @item --gpg=@var{command}
9110 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9111 for in @code{$PATH}.
9113 @item --keyring=@var{file}
9114 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9115 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9116 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9117 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9118 information on a tool to manipulate keybox files).
9120 When this option is omitted, @command{guix refresh} uses
9121 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9122 signing keys. OpenPGP signatures are checked against keys from this keyring;
9123 missing keys are downloaded to this keyring as well (see
9124 @option{--key-download} below.)
9126 You can export keys from your default GPG keyring into a keybox file using
9127 commands like this one:
9130 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9133 Likewise, you can fetch keys to a specific keybox file like this:
9136 gpg --no-default-keyring --keyring mykeyring.kbx \
9137 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9140 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9141 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9143 @item --key-download=@var{policy}
9144 Handle missing OpenPGP keys according to @var{policy}, which may be one
9149 Always download missing OpenPGP keys from the key server, and add them
9150 to the user's GnuPG keyring.
9153 Never try to download missing OpenPGP keys. Instead just bail out.
9156 When a package signed with an unknown OpenPGP key is encountered, ask
9157 the user whether to download it or not. This is the default behavior.
9160 @item --key-server=@var{host}
9161 Use @var{host} as the OpenPGP key server when importing a public key.
9165 The @code{github} updater uses the
9166 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9167 releases. When used repeatedly e.g.@: when refreshing all packages,
9168 GitHub will eventually refuse to answer any further API requests. By
9169 default 60 API requests per hour are allowed, and a full refresh on all
9170 GitHub packages in Guix requires more than this. Authentication with
9171 GitHub through the use of an API token alleviates these limits. To use
9172 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9173 token procured from @uref{https://github.com/settings/tokens} or
9177 @node Invoking guix lint
9178 @section Invoking @command{guix lint}
9180 @cindex @command{guix lint}
9181 @cindex package, checking for errors
9182 The @command{guix lint} command is meant to help package developers avoid
9183 common errors and use a consistent style. It runs a number of checks on
9184 a given set of packages in order to find common mistakes in their
9185 definitions. Available @dfn{checkers} include (see
9186 @code{--list-checkers} for a complete list):
9191 Validate certain typographical and stylistic rules about package
9192 descriptions and synopses.
9194 @item inputs-should-be-native
9195 Identify inputs that should most likely be native inputs.
9201 @itemx source-file-name
9202 Probe @code{home-page} and @code{source} URLs and report those that are
9203 invalid. Suggest a @code{mirror://} URL when applicable. If the
9204 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9205 URL. Check that the source file name is meaningful, e.g.@: is not just a
9206 version number or ``git-checkout'', without a declared @code{file-name}
9207 (@pxref{origin Reference}).
9209 @item source-unstable-tarball
9210 Parse the @code{source} URL to determine if a tarball from GitHub is
9211 autogenerated or if it is a release tarball. Unfortunately GitHub's
9212 autogenerated tarballs are sometimes regenerated.
9215 @cindex security vulnerabilities
9216 @cindex CVE, Common Vulnerabilities and Exposures
9217 Report known vulnerabilities found in the Common Vulnerabilities and
9218 Exposures (CVE) databases of the current and past year
9219 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9222 To view information about a particular vulnerability, visit pages such as:
9226 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9228 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9232 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9233 @code{CVE-2015-7554}.
9235 Package developers can specify in package recipes the
9236 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9237 name and version of the package when they differ from the name or version
9238 that Guix uses, as in this example:
9244 ;; CPE calls this package "grub2".
9245 (properties '((cpe-name . "grub2")
9246 (cpe-version . "2.3")))
9249 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9250 Some entries in the CVE database do not specify which version of a
9251 package they apply to, and would thus ``stick around'' forever. Package
9252 developers who found CVE alerts and verified they can be ignored can
9253 declare them as in this example:
9259 ;; These CVEs no longer apply and can be safely ignored.
9260 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9263 "CVE-2011-5244")))))
9267 Warn about obvious source code formatting issues: trailing white space,
9268 use of tabulations, etc.
9271 The general syntax is:
9274 guix lint @var{options} @var{package}@dots{}
9277 If no package is given on the command line, then all packages are checked.
9278 The @var{options} may be zero or more of the following:
9281 @item --list-checkers
9283 List and describe all the available checkers that will be run on packages
9288 Only enable the checkers specified in a comma-separated list using the
9289 names returned by @code{--list-checkers}.
9293 @node Invoking guix size
9294 @section Invoking @command{guix size}
9297 @cindex package size
9299 @cindex @command{guix size}
9300 The @command{guix size} command helps package developers profile the
9301 disk usage of packages. It is easy to overlook the impact of an
9302 additional dependency added to a package, or the impact of using a
9303 single output for a package that could easily be split (@pxref{Packages
9304 with Multiple Outputs}). Such are the typical issues that
9305 @command{guix size} can highlight.
9307 The command can be passed one or more package specifications
9308 such as @code{gcc@@4.8}
9309 or @code{guile:debug}, or a file name in the store. Consider this
9313 $ guix size coreutils
9314 store item total self
9315 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9316 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9317 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9318 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9319 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9320 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9321 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9322 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9327 The store items listed here constitute the @dfn{transitive closure} of
9328 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9329 would be returned by:
9332 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9335 Here the output shows three columns next to store items. The first column,
9336 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9337 the store item---that is, its own size plus the size of all its
9338 dependencies. The next column, labeled ``self'', shows the size of the
9339 item itself. The last column shows the ratio of the size of the item
9340 itself to the space occupied by all the items listed here.
9342 In this example, we see that the closure of Coreutils weighs in at
9343 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9344 libraries. (That libc and GCC's libraries represent a large fraction of
9345 the closure is not a problem @i{per se} because they are always available
9346 on the system anyway.)
9348 When the package(s) passed to @command{guix size} are available in the
9349 store@footnote{More precisely, @command{guix size} looks for the
9350 @emph{ungrafted} variant of the given package(s), as returned by
9351 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9352 for information on grafts.}, @command{guix size} queries the daemon to determine its
9353 dependencies, and measures its size in the store, similar to @command{du
9354 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9357 When the given packages are @emph{not} in the store, @command{guix size}
9358 reports information based on the available substitutes
9359 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9360 store items that are not even on disk, only available remotely.
9362 You can also specify several package names:
9365 $ guix size coreutils grep sed bash
9366 store item total self
9367 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9368 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9369 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9370 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9376 In this example we see that the combination of the four packages takes
9377 102.3@tie{}MiB in total, which is much less than the sum of each closure
9378 since they have a lot of dependencies in common.
9380 The available options are:
9384 @item --substitute-urls=@var{urls}
9385 Use substitute information from @var{urls}.
9386 @xref{client-substitute-urls, the same option for @code{guix build}}.
9388 @item --sort=@var{key}
9389 Sort lines according to @var{key}, one of the following options:
9393 the size of each item (the default);
9395 the total size of the item's closure.
9398 @item --map-file=@var{file}
9399 Write a graphical map of disk usage in PNG format to @var{file}.
9401 For the example above, the map looks like this:
9403 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9404 produced by @command{guix size}}
9406 This option requires that
9407 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9408 installed and visible in Guile's module search path. When that is not
9409 the case, @command{guix size} fails as it tries to load it.
9411 @item --system=@var{system}
9412 @itemx -s @var{system}
9413 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9417 @node Invoking guix graph
9418 @section Invoking @command{guix graph}
9421 @cindex @command{guix graph}
9422 @cindex package dependencies
9423 Packages and their dependencies form a @dfn{graph}, specifically a
9424 directed acyclic graph (DAG). It can quickly become difficult to have a
9425 mental model of the package DAG, so the @command{guix graph} command
9426 provides a visual representation of the DAG. By default,
9427 @command{guix graph} emits a DAG representation in the input format of
9428 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9429 directly to the @command{dot} command of Graphviz. It can also emit an
9430 HTML page with embedded JavaScript code to display a ``chord diagram''
9431 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9432 emit Cypher queries to construct a graph in a graph database supporting
9433 the @uref{https://www.opencypher.org/, openCypher} query language.
9434 The general syntax is:
9437 guix graph @var{options} @var{package}@dots{}
9440 For example, the following command generates a PDF file representing the
9441 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9445 guix graph coreutils | dot -Tpdf > dag.pdf
9448 The output looks like this:
9450 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9452 Nice little graph, no?
9454 But there is more than one graph! The one above is concise: it is the
9455 graph of package objects, omitting implicit inputs such as GCC, libc,
9456 grep, etc. It is often useful to have such a concise graph, but
9457 sometimes one may want to see more details. @command{guix graph} supports
9458 several types of graphs, allowing you to choose the level of detail:
9462 This is the default type used in the example above. It shows the DAG of
9463 package objects, excluding implicit dependencies. It is concise, but
9464 filters out many details.
9466 @item reverse-package
9467 This shows the @emph{reverse} DAG of packages. For example:
9470 guix graph --type=reverse-package ocaml
9473 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9474 you are also interested in cases where OCaml is an implicit dependency, see
9475 @code{reverse-bag} below.)
9477 Note that for core packages this can yield huge graphs. If all you want
9478 is to know the number of packages that depend on a given package, use
9479 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9480 @option{--list-dependent}}).
9483 This is the package DAG, @emph{including} implicit inputs.
9485 For instance, the following command:
9488 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9491 ...@: yields this bigger graph:
9493 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9495 At the bottom of the graph, we see all the implicit inputs of
9496 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9498 Now, note that the dependencies of these implicit inputs---that is, the
9499 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9500 here, for conciseness.
9503 Similar to @code{bag-emerged}, but this time including all the bootstrap
9506 @item bag-with-origins
9507 Similar to @code{bag}, but also showing origins and their dependencies.
9510 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9511 it also takes implicit dependencies into account. For example:
9514 guix graph -t reverse-bag dune
9518 ...@: yields the graph of all packages that depend on Dune, directly or
9519 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9520 @i{via} @code{dune-build-system}, this shows a large number of packages,
9521 whereas @code{reverse-package} would show very few if any.
9524 This is the most detailed representation: It shows the DAG of
9525 derivations (@pxref{Derivations}) and plain store items. Compared to
9526 the above representation, many additional nodes are visible, including
9527 build scripts, patches, Guile modules, etc.
9529 For this type of graph, it is also possible to pass a @file{.drv} file
9530 name instead of a package name, as in:
9533 guix graph -t derivation `guix system build -d my-config.scm`
9537 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9538 For example, the following command shows the graph for the package
9539 module that defines the @code{guile} package:
9542 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9546 All the types above correspond to @emph{build-time dependencies}. The
9547 following graph type represents the @emph{run-time dependencies}:
9551 This is the graph of @dfn{references} of a package output, as returned
9552 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9554 If the given package output is not available in the store, @command{guix
9555 graph} attempts to obtain dependency information from substitutes.
9557 Here you can also pass a store file name instead of a package name. For
9558 example, the command below produces the reference graph of your profile
9559 (which can be big!):
9562 guix graph -t references `readlink -f ~/.guix-profile`
9566 This is the graph of the @dfn{referrers} of a store item, as returned by
9567 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9569 This relies exclusively on local information from your store. For
9570 instance, let us suppose that the current Inkscape is available in 10
9571 profiles on your machine; @command{guix graph -t referrers inkscape}
9572 will show a graph rooted at Inkscape and with those 10 profiles linked
9575 It can help determine what is preventing a store item from being garbage
9580 The available options are the following:
9583 @item --type=@var{type}
9584 @itemx -t @var{type}
9585 Produce a graph output of @var{type}, where @var{type} must be one of
9586 the values listed above.
9589 List the supported graph types.
9591 @item --backend=@var{backend}
9592 @itemx -b @var{backend}
9593 Produce a graph using the selected @var{backend}.
9595 @item --list-backends
9596 List the supported graph backends.
9598 Currently, the available backends are Graphviz and d3.js.
9600 @item --expression=@var{expr}
9601 @itemx -e @var{expr}
9602 Consider the package @var{expr} evaluates to.
9604 This is useful to precisely refer to a package, as in this example:
9607 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9610 @item --system=@var{system}
9611 @itemx -s @var{system}
9612 Display the graph for @var{system}---e.g., @code{i686-linux}.
9614 The package dependency graph is largely architecture-independent, but there
9615 are some architecture-dependent bits that this option allows you to visualize.
9620 @node Invoking guix publish
9621 @section Invoking @command{guix publish}
9623 @cindex @command{guix publish}
9624 The purpose of @command{guix publish} is to enable users to easily share
9625 their store with others, who can then use it as a substitute server
9626 (@pxref{Substitutes}).
9628 When @command{guix publish} runs, it spawns an HTTP server which allows
9629 anyone with network access to obtain substitutes from it. This means
9630 that any machine running Guix can also act as if it were a build farm,
9631 since the HTTP interface is compatible with Cuirass, the software behind
9632 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9634 For security, each substitute is signed, allowing recipients to check
9635 their authenticity and integrity (@pxref{Substitutes}). Because
9636 @command{guix publish} uses the signing key of the system, which is only
9637 readable by the system administrator, it must be started as root; the
9638 @code{--user} option makes it drop root privileges early on.
9640 The signing key pair must be generated before @command{guix publish} is
9641 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9644 The general syntax is:
9647 guix publish @var{options}@dots{}
9650 Running @command{guix publish} without any additional arguments will
9651 spawn an HTTP server on port 8080:
9657 Once a publishing server has been authorized (@pxref{Invoking guix
9658 archive}), the daemon may download substitutes from it:
9661 guix-daemon --substitute-urls=http://example.org:8080
9664 By default, @command{guix publish} compresses archives on the fly as it
9665 serves them. This ``on-the-fly'' mode is convenient in that it requires
9666 no setup and is immediately available. However, when serving lots of
9667 clients, we recommend using the @option{--cache} option, which enables
9668 caching of the archives before they are sent to clients---see below for
9669 details. The @command{guix weather} command provides a handy way to
9670 check what a server provides (@pxref{Invoking guix weather}).
9672 As a bonus, @command{guix publish} also serves as a content-addressed
9673 mirror for source files referenced in @code{origin} records
9674 (@pxref{origin Reference}). For instance, assuming @command{guix
9675 publish} is running on @code{example.org}, the following URL returns the
9676 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9677 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9680 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9683 Obviously, these URLs only work for files that are in the store; in
9684 other cases, they return 404 (``Not Found'').
9686 @cindex build logs, publication
9687 Build logs are available from @code{/log} URLs like:
9690 http://example.org/log/gwspk@dots{}-guile-2.2.3
9694 When @command{guix-daemon} is configured to save compressed build logs,
9695 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9696 URLs return the compressed log as-is, with an appropriate
9697 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9698 running @command{guix-daemon} with @code{--log-compression=gzip} since
9699 Web browsers can automatically decompress it, which is not the case with
9702 The following options are available:
9705 @item --port=@var{port}
9706 @itemx -p @var{port}
9707 Listen for HTTP requests on @var{port}.
9709 @item --listen=@var{host}
9710 Listen on the network interface for @var{host}. The default is to
9711 accept connections from any interface.
9713 @item --user=@var{user}
9714 @itemx -u @var{user}
9715 Change privileges to @var{user} as soon as possible---i.e., once the
9716 server socket is open and the signing key has been read.
9718 @item --compression[=@var{method}[:@var{level}]]
9719 @itemx -C [@var{method}[:@var{level}]]
9720 Compress data using the given @var{method} and @var{level}. @var{method} is
9721 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
9724 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
9725 to different compression levels: 1 is the fastest, and 9 is the best
9726 (CPU-intensive). The default is 3.
9728 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
9729 increase in CPU usage; see
9730 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
9733 Unless @option{--cache} is used, compression occurs on the fly and
9734 the compressed streams are not
9735 cached. Thus, to reduce load on the machine that runs @command{guix
9736 publish}, it may be a good idea to choose a low compression level, to
9737 run @command{guix publish} behind a caching proxy, or to use
9738 @option{--cache}. Using @option{--cache} has the advantage that it
9739 allows @command{guix publish} to add @code{Content-Length} HTTP header
9742 This option can be repeated, in which case every substitute gets compressed
9743 using all the selected methods, and all of them are advertised. This is
9744 useful when users may not support all the compression methods: they can select
9745 the one they support.
9747 @item --cache=@var{directory}
9748 @itemx -c @var{directory}
9749 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9750 and only serve archives that are in cache.
9752 When this option is omitted, archives and meta-data are created
9753 on-the-fly. This can reduce the available bandwidth, especially when
9754 compression is enabled, since this may become CPU-bound. Another
9755 drawback of the default mode is that the length of archives is not known
9756 in advance, so @command{guix publish} does not add a
9757 @code{Content-Length} HTTP header to its responses, which in turn
9758 prevents clients from knowing the amount of data being downloaded.
9760 Conversely, when @option{--cache} is used, the first request for a store
9761 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9762 background process to @dfn{bake} the archive---computing its
9763 @code{.narinfo} and compressing the archive, if needed. Once the
9764 archive is cached in @var{directory}, subsequent requests succeed and
9765 are served directly from the cache, which guarantees that clients get
9766 the best possible bandwidth.
9768 The ``baking'' process is performed by worker threads. By default, one
9769 thread per CPU core is created, but this can be customized. See
9770 @option{--workers} below.
9772 When @option{--ttl} is used, cached entries are automatically deleted
9773 when they have expired.
9775 @item --workers=@var{N}
9776 When @option{--cache} is used, request the allocation of @var{N} worker
9777 threads to ``bake'' archives.
9779 @item --ttl=@var{ttl}
9780 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9781 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9782 days, @code{1m} means 1 month, and so on.
9784 This allows the user's Guix to keep substitute information in cache for
9785 @var{ttl}. However, note that @code{guix publish} does not itself
9786 guarantee that the store items it provides will indeed remain available
9787 for as long as @var{ttl}.
9789 Additionally, when @option{--cache} is used, cached entries that have
9790 not been accessed for @var{ttl} and that no longer have a corresponding
9791 item in the store, may be deleted.
9793 @item --nar-path=@var{path}
9794 Use @var{path} as the prefix for the URLs of ``nar'' files
9795 (@pxref{Invoking guix archive, normalized archives}).
9797 By default, nars are served at a URL such as
9798 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9799 change the @code{/nar} part to @var{path}.
9801 @item --public-key=@var{file}
9802 @itemx --private-key=@var{file}
9803 Use the specific @var{file}s as the public/private key pair used to sign
9804 the store items being published.
9806 The files must correspond to the same key pair (the private key is used
9807 for signing and the public key is merely advertised in the signature
9808 metadata). They must contain keys in the canonical s-expression format
9809 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9810 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9811 @file{/etc/guix/signing-key.sec} are used.
9813 @item --repl[=@var{port}]
9814 @itemx -r [@var{port}]
9815 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9816 Reference Manual}) on @var{port} (37146 by default). This is used
9817 primarily for debugging a running @command{guix publish} server.
9820 Enabling @command{guix publish} on Guix System is a one-liner: just
9821 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9822 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9823 @code{guix-publish-service-type}}).
9825 If you are instead running Guix on a ``foreign distro'', follow these
9830 If your host distro uses the systemd init system:
9833 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9834 /etc/systemd/system/
9835 # systemctl start guix-publish && systemctl enable guix-publish
9839 If your host distro uses the Upstart init system:
9842 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9843 # start guix-publish
9847 Otherwise, proceed similarly with your distro's init system.
9850 @node Invoking guix challenge
9851 @section Invoking @command{guix challenge}
9853 @cindex reproducible builds
9854 @cindex verifiable builds
9855 @cindex @command{guix challenge}
9857 Do the binaries provided by this server really correspond to the source
9858 code it claims to build? Is a package build process deterministic?
9859 These are the questions the @command{guix challenge} command attempts to
9862 The former is obviously an important question: Before using a substitute
9863 server (@pxref{Substitutes}), one had better @emph{verify} that it
9864 provides the right binaries, and thus @emph{challenge} it. The latter
9865 is what enables the former: If package builds are deterministic, then
9866 independent builds of the package should yield the exact same result,
9867 bit for bit; if a server provides a binary different from the one
9868 obtained locally, it may be either corrupt or malicious.
9870 We know that the hash that shows up in @file{/gnu/store} file names is
9871 the hash of all the inputs of the process that built the file or
9872 directory---compilers, libraries, build scripts,
9873 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9874 one store file name should map to exactly one build output.
9875 @command{guix challenge} checks whether there is, indeed, a single
9876 mapping by comparing the build outputs of several independent builds of
9877 any given store item.
9879 The command output looks like this:
9882 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9883 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9884 updating list of substitutes from 'https://guix.example.org'... 100.0%
9885 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9886 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9887 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9888 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9889 /gnu/store/@dots{}-git-2.5.0 contents differ:
9890 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9891 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9892 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9893 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9894 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9895 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9896 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9900 6,406 store items were analyzed:
9901 - 4,749 (74.1%) were identical
9902 - 525 (8.2%) differed
9903 - 1,132 (17.7%) were inconclusive
9907 In this example, @command{guix challenge} first scans the store to
9908 determine the set of locally-built derivations---as opposed to store
9909 items that were downloaded from a substitute server---and then queries
9910 all the substitute servers. It then reports those store items for which
9911 the servers obtained a result different from the local build.
9913 @cindex non-determinism, in package builds
9914 As an example, @code{guix.example.org} always gets a different answer.
9915 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9916 case of Git. This might indicate that the build process of Git is
9917 non-deterministic, meaning that its output varies as a function of
9918 various things that Guix does not fully control, in spite of building
9919 packages in isolated environments (@pxref{Features}). Most common
9920 sources of non-determinism include the addition of timestamps in build
9921 results, the inclusion of random numbers, and directory listings sorted
9922 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9925 To find out what is wrong with this Git binary, we can do something along
9926 these lines (@pxref{Invoking guix archive}):
9929 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9930 | guix archive -x /tmp/git
9931 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9934 This command shows the difference between the files resulting from the
9935 local build, and the files resulting from the build on
9936 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9937 diffutils, Comparing and Merging Files}). The @command{diff} command
9938 works great for text files. When binary files differ, a better option
9939 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9940 visualize differences for all kinds of files.
9942 Once you have done that work, you can tell whether the differences are due
9943 to a non-deterministic build process or to a malicious server. We try
9944 hard to remove sources of non-determinism in packages to make it easier
9945 to verify substitutes, but of course, this is a process that
9946 involves not just Guix, but a large part of the free software community.
9947 In the meantime, @command{guix challenge} is one tool to help address
9950 If you are writing packages for Guix, you are encouraged to check
9951 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9952 same build result as you did with:
9955 $ guix challenge @var{package}
9959 where @var{package} is a package specification such as
9960 @code{guile@@2.0} or @code{glibc:debug}.
9962 The general syntax is:
9965 guix challenge @var{options} [@var{packages}@dots{}]
9968 When a difference is found between the hash of a locally-built item and
9969 that of a server-provided substitute, or among substitutes provided by
9970 different servers, the command displays it as in the example above and
9971 its exit code is 2 (other non-zero exit codes denote other kinds of
9974 The one option that matters is:
9978 @item --substitute-urls=@var{urls}
9979 Consider @var{urls} the whitespace-separated list of substitute source
9984 Show details about matches (identical contents) in addition to
9985 information about mismatches.
9989 @node Invoking guix copy
9990 @section Invoking @command{guix copy}
9992 @cindex copy, of store items, over SSH
9993 @cindex SSH, copy of store items
9994 @cindex sharing store items across machines
9995 @cindex transferring store items across machines
9996 The @command{guix copy} command copies items from the store of one
9997 machine to that of another machine over a secure shell (SSH)
9998 connection@footnote{This command is available only when Guile-SSH was
9999 found. @xref{Requirements}, for details.}. For example, the following
10000 command copies the @code{coreutils} package, the user's profile, and all
10001 their dependencies over to @var{host}, logged in as @var{user}:
10004 guix copy --to=@var{user}@@@var{host} \
10005 coreutils `readlink -f ~/.guix-profile`
10008 If some of the items to be copied are already present on @var{host},
10009 they are not actually sent.
10011 The command below retrieves @code{libreoffice} and @code{gimp} from
10012 @var{host}, assuming they are available there:
10015 guix copy --from=@var{host} libreoffice gimp
10018 The SSH connection is established using the Guile-SSH client, which is
10019 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10020 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10022 The key used to sign items that are sent must be accepted by the remote
10023 machine. Likewise, the key used by the remote machine to sign items you
10024 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10025 own daemon. @xref{Invoking guix archive}, for more information about
10026 store item authentication.
10028 The general syntax is:
10031 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10034 You must always specify one of the following options:
10037 @item --to=@var{spec}
10038 @itemx --from=@var{spec}
10039 Specify the host to send to or receive from. @var{spec} must be an SSH
10040 spec such as @code{example.org}, @code{charlie@@example.org}, or
10041 @code{charlie@@example.org:2222}.
10044 The @var{items} can be either package names, such as @code{gimp}, or
10045 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10047 When specifying the name of a package to send, it is first built if
10048 needed, unless @option{--dry-run} was specified. Common build options
10049 are supported (@pxref{Common Build Options}).
10052 @node Invoking guix container
10053 @section Invoking @command{guix container}
10055 @cindex @command{guix container}
10057 As of version @value{VERSION}, this tool is experimental. The interface
10058 is subject to radical change in the future.
10061 The purpose of @command{guix container} is to manipulate processes
10062 running within an isolated environment, commonly known as a
10063 ``container'', typically created by the @command{guix environment}
10064 (@pxref{Invoking guix environment}) and @command{guix system container}
10065 (@pxref{Invoking guix system}) commands.
10067 The general syntax is:
10070 guix container @var{action} @var{options}@dots{}
10073 @var{action} specifies the operation to perform with a container, and
10074 @var{options} specifies the context-specific arguments for the action.
10076 The following actions are available:
10080 Execute a command within the context of a running container.
10085 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10088 @var{pid} specifies the process ID of the running container.
10089 @var{program} specifies an executable file name within the root file
10090 system of the container. @var{arguments} are the additional options that
10091 will be passed to @var{program}.
10093 The following command launches an interactive login shell inside a
10094 Guix system container, started by @command{guix system container}, and whose
10095 process ID is 9001:
10098 guix container exec 9001 /run/current-system/profile/bin/bash --login
10101 Note that the @var{pid} cannot be the parent process of a container. It
10102 must be PID 1 of the container or one of its child processes.
10106 @node Invoking guix weather
10107 @section Invoking @command{guix weather}
10109 Occasionally you're grumpy because substitutes are lacking and you end
10110 up building packages by yourself (@pxref{Substitutes}). The
10111 @command{guix weather} command reports on substitute availability on the
10112 specified servers so you can have an idea of whether you'll be grumpy
10113 today. It can sometimes be useful info as a user, but it is primarily
10114 useful to people running @command{guix publish} (@pxref{Invoking guix
10117 @cindex statistics, for substitutes
10118 @cindex availability of substitutes
10119 @cindex substitute availability
10120 @cindex weather, substitute availability
10121 Here's a sample run:
10124 $ guix weather --substitute-urls=https://guix.example.org
10125 computing 5,872 package derivations for x86_64-linux...
10126 looking for 6,128 store items on https://guix.example.org..
10127 updating list of substitutes from 'https://guix.example.org'... 100.0%
10128 https://guix.example.org
10129 43.4% substitutes available (2,658 out of 6,128)
10130 7,032.5 MiB of nars (compressed)
10131 19,824.2 MiB on disk (uncompressed)
10132 0.030 seconds per request (182.9 seconds in total)
10133 33.5 requests per second
10135 9.8% (342 out of 3,470) of the missing items are queued
10137 x86_64-linux: 518 (59.7%)
10138 i686-linux: 221 (25.5%)
10139 aarch64-linux: 128 (14.8%)
10140 build rate: 23.41 builds per hour
10141 x86_64-linux: 11.16 builds per hour
10142 i686-linux: 6.03 builds per hour
10143 aarch64-linux: 6.41 builds per hour
10146 @cindex continuous integration, statistics
10147 As you can see, it reports the fraction of all the packages for which
10148 substitutes are available on the server---regardless of whether
10149 substitutes are enabled, and regardless of whether this server's signing
10150 key is authorized. It also reports the size of the compressed archives
10151 (``nars'') provided by the server, the size the corresponding store
10152 items occupy in the store (assuming deduplication is turned off), and
10153 the server's throughput. The second part gives continuous integration
10154 (CI) statistics, if the server supports it. In addition, using the
10155 @option{--coverage} option, @command{guix weather} can list ``important''
10156 package substitutes missing on the server (see below).
10158 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10159 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10160 challenge}, it ignores signatures on those substitutes, which is
10161 innocuous since the command only gathers statistics and cannot install
10164 The general syntax is:
10167 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10170 When @var{packages} is omitted, @command{guix weather} checks the availability
10171 of substitutes for @emph{all} the packages, or for those specified with
10172 @option{--manifest}; otherwise it only considers the specified packages. It
10173 is also possible to query specific system types with @option{--system}. The
10174 available options are listed below.
10177 @item --substitute-urls=@var{urls}
10178 @var{urls} is the space-separated list of substitute server URLs to
10179 query. When this option is omitted, the default set of substitute
10180 servers is queried.
10182 @item --system=@var{system}
10183 @itemx -s @var{system}
10184 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10185 option can be repeated, in which case @command{guix weather} will query
10186 substitutes for several system types.
10188 @item --manifest=@var{file}
10189 Instead of querying substitutes for all the packages, only ask for those
10190 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10191 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10194 @item --coverage[=@var{count}]
10195 @itemx -c [@var{count}]
10196 Report on substitute coverage for packages: list packages with at least
10197 @var{count} dependents (zero by default) for which substitutes are
10198 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10199 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10200 @var{b} usually lacks substitutes as well. The result looks like this:
10203 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10204 computing 8,983 package derivations for x86_64-linux...
10205 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10206 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10207 @value{SUBSTITUTE-URL}
10208 64.7% substitutes available (6,047 out of 9,343)
10210 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10211 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10212 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10213 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10217 What this example shows is that @code{kcoreaddons} and presumably the 58
10218 packages that depend on it have no substitutes at @code{ci.guix.info};
10219 likewise for @code{qgpgme} and the 46 packages that depend on it.
10221 If you are a Guix developer, or if you are taking care of this build farm,
10222 you'll probably want to have a closer look at these packages: they may simply
10226 @node Invoking guix processes
10227 @section Invoking @command{guix processes}
10229 The @command{guix processes} command can be useful to developers and system
10230 administrators, especially on multi-user machines and on build farms: it lists
10231 the current sessions (connections to the daemon), as well as information about
10232 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10233 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10234 listed.}. Here's an example of the information it returns:
10237 $ sudo guix processes
10240 ClientCommand: guix environment --ad-hoc python
10244 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10248 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10249 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10250 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10251 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10252 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10253 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10254 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10257 In this example we see that @command{guix-daemon} has three clients:
10258 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10259 integration tool; their process identifier (PID) is given by the
10260 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10261 @command{guix-daemon} sub-process of this particular session.
10263 The @code{LockHeld} fields show which store items are currently locked by this
10264 session, which corresponds to store items being built or substituted (the
10265 @code{LockHeld} field is not displayed when @command{guix processes} is not
10266 running as root.) Last, by looking at the @code{ChildProcess} field, we
10267 understand that these three builds are being offloaded (@pxref{Daemon Offload
10270 The output is in Recutils format so we can use the handy @command{recsel}
10271 command to select sessions of interest (@pxref{Selection Expressions,,,
10272 recutils, GNU recutils manual}). As an example, the command shows the command
10273 line and PID of the client that triggered the build of a Perl package:
10276 $ sudo guix processes | \
10277 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10279 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10283 @node System Configuration
10284 @chapter System Configuration
10286 @cindex system configuration
10287 Guix System supports a consistent whole-system configuration
10288 mechanism. By that we mean that all aspects of the global system
10289 configuration---such as the available system services, timezone and
10290 locale settings, user accounts---are declared in a single place. Such
10291 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10293 One of the advantages of putting all the system configuration under the
10294 control of Guix is that it supports transactional system upgrades, and
10295 makes it possible to roll back to a previous system instantiation,
10296 should something go wrong with the new one (@pxref{Features}). Another
10297 advantage is that it makes it easy to replicate the exact same configuration
10298 across different machines, or at different points in time, without
10299 having to resort to additional administration tools layered on top of
10300 the own tools of the system.
10301 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10303 This section describes this mechanism. First we focus on the system
10304 administrator's viewpoint---explaining how the system is configured and
10305 instantiated. Then we show how this mechanism can be extended, for
10306 instance to support new system services.
10309 * Using the Configuration System:: Customizing your GNU system.
10310 * operating-system Reference:: Detail of operating-system declarations.
10311 * File Systems:: Configuring file system mounts.
10312 * Mapped Devices:: Block device extra processing.
10313 * User Accounts:: Specifying user accounts.
10314 * Keyboard Layout:: How the system interprets key strokes.
10315 * Locales:: Language and cultural convention settings.
10316 * Services:: Specifying system services.
10317 * Setuid Programs:: Programs running with root privileges.
10318 * X.509 Certificates:: Authenticating HTTPS servers.
10319 * Name Service Switch:: Configuring libc's name service switch.
10320 * Initial RAM Disk:: Linux-Libre bootstrapping.
10321 * Bootloader Configuration:: Configuring the boot loader.
10322 * Invoking guix system:: Instantiating a system configuration.
10323 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10324 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10325 * Defining Services:: Adding new service definitions.
10328 @node Using the Configuration System
10329 @section Using the Configuration System
10331 The operating system is configured by providing an
10332 @code{operating-system} declaration in a file that can then be passed to
10333 the @command{guix system} command (@pxref{Invoking guix system}). A
10334 simple setup, with the default system services, the default Linux-Libre
10335 kernel, initial RAM disk, and boot loader looks like this:
10337 @findex operating-system
10339 @include os-config-bare-bones.texi
10342 This example should be self-describing. Some of the fields defined
10343 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10344 Others, such as @code{packages} and @code{services}, can be omitted, in
10345 which case they get a default value.
10347 Below we discuss the effect of some of the most important fields
10348 (@pxref{operating-system Reference}, for details about all the available
10349 fields), and how to @dfn{instantiate} the operating system using
10350 @command{guix system}.
10352 @unnumberedsubsec Bootloader
10354 @cindex legacy boot, on Intel machines
10355 @cindex BIOS boot, on Intel machines
10358 The @code{bootloader} field describes the method that will be used to boot
10359 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10360 mode, as in the example above. However, more recent machines rely instead on
10361 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10362 the @code{bootloader} field should contain something along these lines:
10365 (bootloader-configuration
10366 (bootloader grub-efi-bootloader)
10367 (target "/boot/efi"))
10370 @xref{Bootloader Configuration}, for more information on the available
10371 configuration options.
10373 @unnumberedsubsec Globally-Visible Packages
10375 @vindex %base-packages
10376 The @code{packages} field lists packages that will be globally visible
10377 on the system, for all user accounts---i.e., in every user's @code{PATH}
10378 environment variable---in addition to the per-user profiles
10379 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10380 provides all the tools one would expect for basic user and administrator
10381 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10382 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10383 etc. The example above adds GNU@tie{}Screen to those,
10384 taken from the @code{(gnu packages screen)}
10385 module (@pxref{Package Modules}). The
10386 @code{(list package output)} syntax can be used to add a specific output
10390 (use-modules (gnu packages))
10391 (use-modules (gnu packages dns))
10395 (packages (cons (list bind "utils")
10399 @findex specification->package
10400 Referring to packages by variable name, like @code{bind} above, has
10401 the advantage of being unambiguous; it also allows typos and such to be
10402 diagnosed right away as ``unbound variables''. The downside is that one
10403 needs to know which module defines which package, and to augment the
10404 @code{use-package-modules} line accordingly. To avoid that, one can use
10405 the @code{specification->package} procedure of the @code{(gnu packages)}
10406 module, which returns the best package for a given name or name and
10410 (use-modules (gnu packages))
10414 (packages (append (map specification->package
10415 '("tcpdump" "htop" "gnupg@@2.0"))
10419 @unnumberedsubsec System Services
10422 @vindex %base-services
10423 The @code{services} field lists @dfn{system services} to be made
10424 available when the system starts (@pxref{Services}).
10425 The @code{operating-system} declaration above specifies that, in
10426 addition to the basic services, we want the OpenSSH secure shell
10427 daemon listening on port 2222 (@pxref{Networking Services,
10428 @code{openssh-service-type}}). Under the hood,
10429 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10430 right command-line options, possibly with supporting configuration files
10431 generated as needed (@pxref{Defining Services}).
10433 @cindex customization, of services
10434 @findex modify-services
10435 Occasionally, instead of using the base services as is, you will want to
10436 customize them. To do this, use @code{modify-services} (@pxref{Service
10437 Reference, @code{modify-services}}) to modify the list.
10439 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10440 (the console log-in) in the @code{%base-services} list (@pxref{Base
10441 Services, @code{%base-services}}). To do that, you can write the
10442 following in your operating system declaration:
10445 (define %my-services
10446 ;; My very own list of services.
10447 (modify-services %base-services
10448 (guix-service-type config =>
10449 (guix-configuration
10451 (use-substitutes? #f)
10452 (extra-options '("--gc-keep-derivations"))))
10453 (mingetty-service-type config =>
10454 (mingetty-configuration
10455 (inherit config)))))
10459 (services %my-services))
10462 This changes the configuration---i.e., the service parameters---of the
10463 @code{guix-service-type} instance, and that of all the
10464 @code{mingetty-service-type} instances in the @code{%base-services} list.
10465 Observe how this is accomplished: first, we arrange for the original
10466 configuration to be bound to the identifier @code{config} in the
10467 @var{body}, and then we write the @var{body} so that it evaluates to the
10468 desired configuration. In particular, notice how we use @code{inherit}
10469 to create a new configuration which has the same values as the old
10470 configuration, but with a few modifications.
10472 @cindex encrypted disk
10473 The configuration for a typical ``desktop'' usage, with an encrypted
10474 root partition, the X11 display
10475 server, GNOME and Xfce (users can choose which of these desktop
10476 environments to use at the log-in screen by pressing @kbd{F1}), network
10477 management, power management, and more, would look like this:
10480 @include os-config-desktop.texi
10483 A graphical system with a choice of lightweight window managers
10484 instead of full-blown desktop environments would look like this:
10487 @include os-config-lightweight-desktop.texi
10490 This example refers to the @file{/boot/efi} file system by its UUID,
10491 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10492 as returned by the @command{blkid} command.
10494 @xref{Desktop Services}, for the exact list of services provided by
10495 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10496 information about the @code{nss-certs} package that is used here.
10498 Again, @code{%desktop-services} is just a list of service objects. If
10499 you want to remove services from there, you can do so using the
10500 procedures for list filtering (@pxref{SRFI-1 Filtering and
10501 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10502 following expression returns a list that contains all the services in
10503 @code{%desktop-services} minus the Avahi service:
10506 (remove (lambda (service)
10507 (eq? (service-kind service) avahi-service-type))
10511 @unnumberedsubsec Instantiating the System
10513 Assuming the @code{operating-system} declaration
10514 is stored in the @file{my-system-config.scm}
10515 file, the @command{guix system reconfigure my-system-config.scm} command
10516 instantiates that configuration, and makes it the default GRUB boot
10517 entry (@pxref{Invoking guix system}).
10519 The normal way to change the system configuration is by updating this
10520 file and re-running @command{guix system reconfigure}. One should never
10521 have to touch files in @file{/etc} or to run commands that modify the
10522 system state such as @command{useradd} or @command{grub-install}. In
10523 fact, you must avoid that since that would not only void your warranty
10524 but also prevent you from rolling back to previous versions of your
10525 system, should you ever need to.
10527 @cindex roll-back, of the operating system
10528 Speaking of roll-back, each time you run @command{guix system
10529 reconfigure}, a new @dfn{generation} of the system is created---without
10530 modifying or deleting previous generations. Old system generations get
10531 an entry in the bootloader boot menu, allowing you to boot them in case
10532 something went wrong with the latest generation. Reassuring, no? The
10533 @command{guix system list-generations} command lists the system
10534 generations available on disk. It is also possible to roll back the
10535 system via the commands @command{guix system roll-back} and
10536 @command{guix system switch-generation}.
10538 Although the @command{guix system reconfigure} command will not modify
10539 previous generations, you must take care when the current generation is not
10540 the latest (e.g., after invoking @command{guix system roll-back}), since
10541 the operation might overwrite a later generation (@pxref{Invoking guix
10544 @unnumberedsubsec The Programming Interface
10546 At the Scheme level, the bulk of an @code{operating-system} declaration
10547 is instantiated with the following monadic procedure (@pxref{The Store
10550 @deffn {Monadic Procedure} operating-system-derivation os
10551 Return a derivation that builds @var{os}, an @code{operating-system}
10552 object (@pxref{Derivations}).
10554 The output of the derivation is a single directory that refers to all
10555 the packages, configuration files, and other supporting files needed to
10556 instantiate @var{os}.
10559 This procedure is provided by the @code{(gnu system)} module. Along
10560 with @code{(gnu services)} (@pxref{Services}), this module contains the
10561 guts of Guix System. Make sure to visit it!
10564 @node operating-system Reference
10565 @section @code{operating-system} Reference
10567 This section summarizes all the options available in
10568 @code{operating-system} declarations (@pxref{Using the Configuration
10571 @deftp {Data Type} operating-system
10572 This is the data type representing an operating system configuration.
10573 By that, we mean all the global system configuration, not per-user
10574 configuration (@pxref{Using the Configuration System}).
10577 @item @code{kernel} (default: @var{linux-libre})
10578 The package object of the operating system kernel to use@footnote{Currently
10579 only the Linux-libre kernel is supported. In the future, it will be
10580 possible to use the GNU@tie{}Hurd.}.
10582 @item @code{kernel-arguments} (default: @code{'("quiet")})
10583 List of strings or gexps representing additional arguments to pass on
10584 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10586 @item @code{bootloader}
10587 The system bootloader configuration object. @xref{Bootloader Configuration}.
10590 This is the label (a string) as it appears in the bootloader's menu entry.
10591 The default label includes the kernel name and version.
10593 @item @code{keyboard-layout} (default: @code{#f})
10594 This field specifies the keyboard layout to use in the console. It can be
10595 either @code{#f}, in which case the default keyboard layout is used (usually
10596 US English), or a @code{<keyboard-layout>} record.
10598 This keyboard layout is in effect as soon as the kernel has booted. For
10599 instance, it is the keyboard layout in effect when you type a passphrase if
10600 your root file system is on a @code{luks-device-mapping} mapped device
10601 (@pxref{Mapped Devices}).
10604 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10605 that used by the graphical display server. @xref{Bootloader Configuration},
10606 for information on how to specify the bootloader's keyboard layout. @xref{X
10607 Window}, for information on how to specify the keyboard layout used by the X
10611 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10613 @cindex initial RAM disk
10614 The list of Linux kernel modules that need to be available in the
10615 initial RAM disk. @xref{Initial RAM Disk}.
10617 @item @code{initrd} (default: @code{base-initrd})
10618 A procedure that returns an initial RAM disk for the Linux
10619 kernel. This field is provided to support low-level customization and
10620 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10622 @item @code{firmware} (default: @code{%base-firmware})
10624 List of firmware packages loadable by the operating system kernel.
10626 The default includes firmware needed for Atheros- and Broadcom-based
10627 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10628 respectively). @xref{Hardware Considerations}, for more info on
10629 supported hardware.
10631 @item @code{host-name}
10634 @item @code{hosts-file}
10636 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10637 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10638 Reference Manual}). The default is a file with entries for
10639 @code{localhost} and @var{host-name}.
10641 @item @code{mapped-devices} (default: @code{'()})
10642 A list of mapped devices. @xref{Mapped Devices}.
10644 @item @code{file-systems}
10645 A list of file systems. @xref{File Systems}.
10647 @item @code{swap-devices} (default: @code{'()})
10648 @cindex swap devices
10649 A list of strings identifying devices or files to be used for ``swap
10650 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10651 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10652 It is possible to specify a swap file in a file system on a mapped
10653 device, provided that the necessary device mapping and file system are
10654 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10656 @item @code{users} (default: @code{%base-user-accounts})
10657 @itemx @code{groups} (default: @code{%base-groups})
10658 List of user accounts and groups. @xref{User Accounts}.
10660 If the @code{users} list lacks a user account with UID@tie{}0, a
10661 ``root'' account with UID@tie{}0 is automatically added.
10663 @item @code{skeletons} (default: @code{(default-skeletons)})
10664 A list target file name/file-like object tuples (@pxref{G-Expressions,
10665 file-like objects}). These are the skeleton files that will be added to
10666 the home directory of newly-created user accounts.
10668 For instance, a valid value may look like this:
10671 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10672 (".guile" ,(plain-file "guile"
10673 "(use-modules (ice-9 readline))
10674 (activate-readline)")))
10677 @item @code{issue} (default: @code{%default-issue})
10678 A string denoting the contents of the @file{/etc/issue} file, which is
10679 displayed when users log in on a text console.
10681 @item @code{packages} (default: @code{%base-packages})
10682 The set of packages installed in the global profile, which is accessible
10683 at @file{/run/current-system/profile}.
10685 The default set includes core utilities and it is good practice to
10686 install non-core utilities in user profiles (@pxref{Invoking guix
10689 @item @code{timezone}
10690 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10692 You can run the @command{tzselect} command to find out which timezone
10693 string corresponds to your region. Choosing an invalid timezone name
10694 causes @command{guix system} to fail.
10696 @item @code{locale} (default: @code{"en_US.utf8"})
10697 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10698 Library Reference Manual}). @xref{Locales}, for more information.
10700 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
10701 The list of locale definitions to be compiled and that may be used at
10702 run time. @xref{Locales}.
10704 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10705 The list of GNU@tie{}libc packages whose locale data and tools are used
10706 to build the locale definitions. @xref{Locales}, for compatibility
10707 considerations that justify this option.
10709 @item @code{name-service-switch} (default: @code{%default-nss})
10710 Configuration of the libc name service switch (NSS)---a
10711 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10714 @item @code{services} (default: @code{%base-services})
10715 A list of service objects denoting system services. @xref{Services}.
10717 @cindex essential services
10718 @item @code{essential-services} (default: ...)
10719 The list of ``essential services''---i.e., things like instances of
10720 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10721 Reference}), which are derived from the operating system definition itself.
10722 As a user you should @emph{never} need to touch this field.
10724 @item @code{pam-services} (default: @code{(base-pam-services)})
10726 @cindex pluggable authentication modules
10727 Linux @dfn{pluggable authentication module} (PAM) services.
10728 @c FIXME: Add xref to PAM services section.
10730 @item @code{setuid-programs} (default: @var{%setuid-programs})
10731 List of string-valued G-expressions denoting setuid programs.
10732 @xref{Setuid Programs}.
10734 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10735 @cindex sudoers file
10736 The contents of the @file{/etc/sudoers} file as a file-like object
10737 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10739 This file specifies which users can use the @command{sudo} command, what
10740 they are allowed to do, and what privileges they may gain. The default
10741 is that only @code{root} and members of the @code{wheel} group may use
10746 @deffn {Scheme Syntax} this-operating-system
10747 When used in the @emph{lexical scope} of an operating system field definition,
10748 this identifier resolves to the operating system being defined.
10750 The example below shows how to refer to the operating system being defined in
10751 the definition of the @code{label} field:
10754 (use-modules (gnu) (guix))
10758 (label (package-full-name
10759 (operating-system-kernel this-operating-system))))
10762 It is an error to refer to @code{this-operating-system} outside an operating
10769 @section File Systems
10771 The list of file systems to be mounted is specified in the
10772 @code{file-systems} field of the operating system declaration
10773 (@pxref{Using the Configuration System}). Each file system is declared
10774 using the @code{file-system} form, like this:
10778 (mount-point "/home")
10779 (device "/dev/sda3")
10783 As usual, some of the fields are mandatory---those shown in the example
10784 above---while others can be omitted. These are described below.
10786 @deftp {Data Type} file-system
10787 Objects of this type represent file systems to be mounted. They
10788 contain the following members:
10792 This is a string specifying the type of the file system---e.g.,
10795 @item @code{mount-point}
10796 This designates the place where the file system is to be mounted.
10798 @item @code{device}
10799 This names the ``source'' of the file system. It can be one of three
10800 things: a file system label, a file system UUID, or the name of a
10801 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10802 systems without having to hard-code their actual device
10803 name@footnote{Note that, while it is tempting to use
10804 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10805 result, this is not recommended: These special device nodes are created
10806 by the udev daemon and may be unavailable at the time the device is
10809 @findex file-system-label
10810 File system labels are created using the @code{file-system-label}
10811 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10812 plain strings. Here's an example of a file system referred to by its
10813 label, as shown by the @command{e2label} command:
10817 (mount-point "/home")
10819 (device (file-system-label "my-home")))
10823 UUIDs are converted from their string representation (as shown by the
10824 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10825 @code{uuid} form expects 16-byte UUIDs as defined in
10826 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10827 form of UUID used by the ext2 family of file systems and others, but it
10828 is different from ``UUIDs'' found in FAT file systems, for instance.},
10833 (mount-point "/home")
10835 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10838 When the source of a file system is a mapped device (@pxref{Mapped
10839 Devices}), its @code{device} field @emph{must} refer to the mapped
10840 device name---e.g., @file{"/dev/mapper/root-partition"}.
10841 This is required so that
10842 the system knows that mounting the file system depends on having the
10843 corresponding device mapping established.
10845 @item @code{flags} (default: @code{'()})
10846 This is a list of symbols denoting mount flags. Recognized flags
10847 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10848 access to special files), @code{no-suid} (ignore setuid and setgid
10849 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10850 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10851 Library Reference Manual}, for more information on these flags.
10853 @item @code{options} (default: @code{#f})
10854 This is either @code{#f}, or a string denoting mount options passed to the
10855 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10856 Reference Manual}, for details and run @command{man 8 mount} for options for
10857 various file systems.
10859 @item @code{mount?} (default: @code{#t})
10860 This value indicates whether to automatically mount the file system when
10861 the system is brought up. When set to @code{#f}, the file system gets
10862 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10863 is not automatically mounted.
10865 @item @code{needed-for-boot?} (default: @code{#f})
10866 This Boolean value indicates whether the file system is needed when
10867 booting. If that is true, then the file system is mounted when the
10868 initial RAM disk (initrd) is loaded. This is always the case, for
10869 instance, for the root file system.
10871 @item @code{check?} (default: @code{#t})
10872 This Boolean indicates whether the file system needs to be checked for
10873 errors before being mounted.
10875 @item @code{create-mount-point?} (default: @code{#f})
10876 When true, the mount point is created if it does not exist yet.
10878 @item @code{dependencies} (default: @code{'()})
10879 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10880 representing file systems that must be mounted or mapped devices that
10881 must be opened before (and unmounted or closed after) this one.
10883 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10884 a dependency of @file{/sys/fs/cgroup/cpu} and
10885 @file{/sys/fs/cgroup/memory}.
10887 Another example is a file system that depends on a mapped device, for
10888 example for an encrypted partition (@pxref{Mapped Devices}).
10892 The @code{(gnu system file-systems)} exports the following useful
10895 @defvr {Scheme Variable} %base-file-systems
10896 These are essential file systems that are required on normal systems,
10897 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10898 below.) Operating system declarations should always contain at least
10902 @defvr {Scheme Variable} %pseudo-terminal-file-system
10903 This is the file system to be mounted as @file{/dev/pts}. It supports
10904 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10905 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10906 Manual}). Pseudo-terminals are used by terminal emulators such as
10910 @defvr {Scheme Variable} %shared-memory-file-system
10911 This file system is mounted as @file{/dev/shm} and is used to support
10912 memory sharing across processes (@pxref{Memory-mapped I/O,
10913 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10916 @defvr {Scheme Variable} %immutable-store
10917 This file system performs a read-only ``bind mount'' of
10918 @file{/gnu/store}, making it read-only for all the users including
10919 @code{root}. This prevents against accidental modification by software
10920 running as @code{root} or by system administrators.
10922 The daemon itself is still able to write to the store: it remounts it
10923 read-write in its own ``name space.''
10926 @defvr {Scheme Variable} %binary-format-file-system
10927 The @code{binfmt_misc} file system, which allows handling of arbitrary
10928 executable file types to be delegated to user space. This requires the
10929 @code{binfmt.ko} kernel module to be loaded.
10932 @defvr {Scheme Variable} %fuse-control-file-system
10933 The @code{fusectl} file system, which allows unprivileged users to mount
10934 and unmount user-space FUSE file systems. This requires the
10935 @code{fuse.ko} kernel module to be loaded.
10938 @node Mapped Devices
10939 @section Mapped Devices
10941 @cindex device mapping
10942 @cindex mapped devices
10943 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10944 such as a hard disk partition, can be @dfn{mapped} into another device,
10945 usually in @code{/dev/mapper/},
10946 with additional processing over the data that flows through
10947 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10948 concept of a ``mapped device'' and that of a file system: both boil down
10949 to @emph{translating} input/output operations made on a file to
10950 operations on its backing store. Thus, the Hurd implements mapped
10951 devices, like file systems, using the generic @dfn{translator} mechanism
10952 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10953 typical example is encryption device mapping: all writes to the mapped
10954 device are encrypted, and all reads are deciphered, transparently.
10955 Guix extends this notion by considering any device or set of devices that
10956 are @dfn{transformed} in some way to create a new device; for instance,
10957 RAID devices are obtained by @dfn{assembling} several other devices, such
10958 as hard disks or partitions, into a new one that behaves as one partition.
10959 Other examples, not yet implemented, are LVM logical volumes.
10961 Mapped devices are declared using the @code{mapped-device} form,
10962 defined as follows; for examples, see below.
10964 @deftp {Data Type} mapped-device
10965 Objects of this type represent device mappings that will be made when
10966 the system boots up.
10970 This is either a string specifying the name of the block device to be mapped,
10971 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10972 need to be assembled for creating a new one.
10975 This string specifies the name of the resulting mapped device. For
10976 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10977 specifying @code{"my-partition"} leads to the creation of
10978 the @code{"/dev/mapper/my-partition"} device.
10979 For RAID devices of type @code{raid-device-mapping}, the full device name
10980 such as @code{"/dev/md0"} needs to be given.
10983 This must be a @code{mapped-device-kind} object, which specifies how
10984 @var{source} is mapped to @var{target}.
10988 @defvr {Scheme Variable} luks-device-mapping
10989 This defines LUKS block device encryption using the @command{cryptsetup}
10990 command from the package with the same name. It relies on the
10991 @code{dm-crypt} Linux kernel module.
10994 @defvr {Scheme Variable} raid-device-mapping
10995 This defines a RAID device, which is assembled using the @code{mdadm}
10996 command from the package with the same name. It requires a Linux kernel
10997 module for the appropriate RAID level to be loaded, such as @code{raid456}
10998 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11001 @cindex disk encryption
11003 The following example specifies a mapping from @file{/dev/sda3} to
11004 @file{/dev/mapper/home} using LUKS---the
11005 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11006 standard mechanism for disk encryption.
11007 The @file{/dev/mapper/home}
11008 device can then be used as the @code{device} of a @code{file-system}
11009 declaration (@pxref{File Systems}).
11013 (source "/dev/sda3")
11015 (type luks-device-mapping))
11018 Alternatively, to become independent of device numbering, one may obtain
11019 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11023 cryptsetup luksUUID /dev/sda3
11026 and use it as follows:
11030 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11032 (type luks-device-mapping))
11035 @cindex swap encryption
11036 It is also desirable to encrypt swap space, since swap space may contain
11037 sensitive data. One way to accomplish that is to use a swap file in a
11038 file system on a device mapped via LUKS encryption. In this way, the
11039 swap file is encrypted because the entire device is encrypted.
11040 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11042 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11043 may be declared as follows:
11047 (source (list "/dev/sda1" "/dev/sdb1"))
11048 (target "/dev/md0")
11049 (type raid-device-mapping))
11052 The @file{/dev/md0} device can then be used as the @code{device} of a
11053 @code{file-system} declaration (@pxref{File Systems}).
11054 Note that the RAID level need not be given; it is chosen during the
11055 initial creation and formatting of the RAID device and is determined
11056 automatically later.
11059 @node User Accounts
11060 @section User Accounts
11064 @cindex user accounts
11065 User accounts and groups are entirely managed through the
11066 @code{operating-system} declaration. They are specified with the
11067 @code{user-account} and @code{user-group} forms:
11073 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11074 "audio" ;sound card
11075 "video" ;video devices such as webcams
11076 "cdrom")) ;the good ol' CD-ROM
11077 (comment "Bob's sister")
11078 (home-directory "/home/alice"))
11081 When booting or upon completion of @command{guix system reconfigure},
11082 the system ensures that only the user accounts and groups specified in
11083 the @code{operating-system} declaration exist, and with the specified
11084 properties. Thus, account or group creations or modifications made by
11085 directly invoking commands such as @command{useradd} are lost upon
11086 reconfiguration or reboot. This ensures that the system remains exactly
11089 @deftp {Data Type} user-account
11090 Objects of this type represent user accounts. The following members may
11095 The name of the user account.
11099 This is the name (a string) or identifier (a number) of the user group
11100 this account belongs to.
11102 @item @code{supplementary-groups} (default: @code{'()})
11103 Optionally, this can be defined as a list of group names that this
11104 account belongs to.
11106 @item @code{uid} (default: @code{#f})
11107 This is the user ID for this account (a number), or @code{#f}. In the
11108 latter case, a number is automatically chosen by the system when the
11109 account is created.
11111 @item @code{comment} (default: @code{""})
11112 A comment about the account, such as the account owner's full name.
11114 @item @code{home-directory}
11115 This is the name of the home directory for the account.
11117 @item @code{create-home-directory?} (default: @code{#t})
11118 Indicates whether the home directory of this account should be created
11119 if it does not exist yet.
11121 @item @code{shell} (default: Bash)
11122 This is a G-expression denoting the file name of a program to be used as
11123 the shell (@pxref{G-Expressions}).
11125 @item @code{system?} (default: @code{#f})
11126 This Boolean value indicates whether the account is a ``system''
11127 account. System accounts are sometimes treated specially; for instance,
11128 graphical login managers do not list them.
11130 @anchor{user-account-password}
11131 @cindex password, for user accounts
11132 @item @code{password} (default: @code{#f})
11133 You would normally leave this field to @code{#f}, initialize user
11134 passwords as @code{root} with the @command{passwd} command, and then let
11135 users change it with @command{passwd}. Passwords set with
11136 @command{passwd} are of course preserved across reboot and
11139 If you @emph{do} want to set an initial password for an account, then
11140 this field must contain the encrypted password, as a string. You can use the
11141 @code{crypt} procedure for this purpose:
11148 ;; Specify a SHA-512-hashed initial password.
11149 (password (crypt "InitialPassword!" "$6$abc")))
11153 The hash of this initial password will be available in a file in
11154 @file{/gnu/store}, readable by all the users, so this method must be used with
11158 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11159 more information on password encryption, and @ref{Encryption,,, guile, GNU
11160 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11166 User group declarations are even simpler:
11169 (user-group (name "students"))
11172 @deftp {Data Type} user-group
11173 This type is for, well, user groups. There are just a few fields:
11177 The name of the group.
11179 @item @code{id} (default: @code{#f})
11180 The group identifier (a number). If @code{#f}, a new number is
11181 automatically allocated when the group is created.
11183 @item @code{system?} (default: @code{#f})
11184 This Boolean value indicates whether the group is a ``system'' group.
11185 System groups have low numerical IDs.
11187 @item @code{password} (default: @code{#f})
11188 What, user groups can have a password? Well, apparently yes. Unless
11189 @code{#f}, this field specifies the password of the group.
11194 For convenience, a variable lists all the basic user groups one may
11197 @defvr {Scheme Variable} %base-groups
11198 This is the list of basic user groups that users and/or packages expect
11199 to be present on the system. This includes groups such as ``root'',
11200 ``wheel'', and ``users'', as well as groups used to control access to
11201 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11204 @defvr {Scheme Variable} %base-user-accounts
11205 This is the list of basic system accounts that programs may expect to
11206 find on a GNU/Linux system, such as the ``nobody'' account.
11208 Note that the ``root'' account is not included here. It is a
11209 special-case and is automatically added whether or not it is specified.
11212 @node Keyboard Layout
11213 @section Keyboard Layout
11215 @cindex keyboard layout
11217 To specify what each key of your keyboard does, you need to tell the operating
11218 system what @dfn{keyboard layout} you want to use. The default, when nothing
11219 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11220 However, German speakers will usually prefer the German QWERTZ layout, French
11221 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11222 or bépo, and they might even want to further customize the effect of some of
11223 the keys. This section explains how to get that done.
11225 @cindex keyboard layout, definition
11226 There are three components that will want to know about your keyboard layout:
11230 The @emph{bootloader} may want to know what keyboard layout you want to use
11231 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11232 you want, for instance, to make sure that you can type the passphrase of your
11233 encrypted root partition using the right layout.
11236 The @emph{operating system kernel}, Linux, will need that so that the console
11237 is properly configured (@pxref{operating-system Reference,
11238 @code{keyboard-layout}}).
11241 The @emph{graphical display server}, usually Xorg, also has its own idea of
11242 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11245 Guix allows you to configure all three separately but, fortunately, it allows
11246 you to share the same keyboard layout for all three components.
11248 @cindex XKB, keyboard layouts
11249 Keyboard layouts are represented by records created by the
11250 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11251 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11252 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11253 optional variant name, an optional keyboard model name, and a possibly empty
11254 list of additional options. In most cases the layout name is all you care
11255 about. Here are a few example:
11258 ;; The German QWERTZ layout. Here we assume a standard
11259 ;; "pc105" keyboard model.
11260 (keyboard-layout "de")
11262 ;; The bépo variant of the French layout.
11263 (keyboard-layout "fr" "bepo")
11265 ;; The Catalan layout.
11266 (keyboard-layout "es" "cat")
11268 ;; The Latin American Spanish layout. In addition, the
11269 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11270 ;; and the "Menu" key is used as a "Compose" key to enter
11271 ;; accented letters.
11272 (keyboard-layout "latam"
11273 #:options '("ctrl:nocaps" "compose:menu"))
11275 ;; The Russian layout for a ThinkPad keyboard.
11276 (keyboard-layout "ru" #:model "thinkpad")
11278 ;; The "US international" layout, which is the US layout plus
11279 ;; dead keys to enter accented characters. This is for an
11280 ;; Apple MacBook keyboard.
11281 (keyboard-layout "us" "intl" #:model "macbook78")
11284 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11285 for a complete list of supported layouts, variants, and models.
11287 @cindex keyboard layout, configuration
11288 Let's say you want your system to use the Turkish keyboard layout throughout
11289 your system---bootloader, console, and Xorg. Here's what your system
11290 configuration would look like:
11292 @findex set-xorg-configuration
11294 ;; Using the Turkish layout for the bootloader, the console,
11299 (keyboard-layout (keyboard-layout "tr")) ;for the console
11300 (bootloader (bootloader-configuration
11301 (bootloader grub-efi-bootloader)
11302 (target "/boot/efi")
11303 (keyboard-layout keyboard-layout))) ;for GRUB
11304 (services (cons (set-xorg-configuration
11305 (xorg-configuration ;for Xorg
11306 (keyboard-layout keyboard-layout)))
11307 %desktop-services)))
11310 In the example above, for GRUB and for Xorg, we just refer to the
11311 @code{keyboard-layout} field defined above, but we could just as well refer to
11312 a different layout. The @code{set-xorg-configuration} procedure communicates
11313 the desired Xorg configuration to the graphical log-in manager, by default
11316 We've discussed how to specify the @emph{default} keyboard layout of your
11317 system when it starts, but you can also adjust it at run time:
11321 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11322 where you can select one or more keyboard layouts.
11325 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11326 allows you to change the current layout. For example, this is how you would
11327 change the layout to US Dvorak:
11330 setxkbmap us dvorak
11334 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11335 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11336 keyboard layout categorization described above. The command below loads the
11337 French bépo layout:
11348 A @dfn{locale} defines cultural conventions for a particular language
11349 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11350 Reference Manual}). Each locale has a name that typically has the form
11351 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11352 @code{fr_LU.utf8} designates the locale for the French language, with
11353 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11355 @cindex locale definition
11356 Usually, you will want to specify the default locale for the machine
11357 using the @code{locale} field of the @code{operating-system} declaration
11358 (@pxref{operating-system Reference, @code{locale}}).
11360 The selected locale is automatically added to the @dfn{locale
11361 definitions} known to the system if needed, with its codeset inferred
11362 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11363 @code{UTF-8} codeset. Additional locale definitions can be specified in
11364 the @code{locale-definitions} slot of @code{operating-system}---this is
11365 useful, for instance, if the codeset could not be inferred from the
11366 locale name. The default set of locale definitions includes some widely
11367 used locales, but not all the available locales, in order to save space.
11369 For instance, to add the North Frisian locale for Germany, the value of
11373 (cons (locale-definition
11374 (name "fy_DE.utf8") (source "fy_DE"))
11375 %default-locale-definitions)
11378 Likewise, to save space, one might want @code{locale-definitions} to
11379 list only the locales that are actually used, as in:
11382 (list (locale-definition
11383 (name "ja_JP.eucjp") (source "ja_JP")
11384 (charset "EUC-JP")))
11388 The compiled locale definitions are available at
11389 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11390 version, which is the default location where the GNU@tie{}libc provided
11391 by Guix looks for locale data. This can be overridden using the
11392 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11393 @code{LOCPATH} and locale packages}).
11395 The @code{locale-definition} form is provided by the @code{(gnu system
11396 locale)} module. Details are given below.
11398 @deftp {Data Type} locale-definition
11399 This is the data type of a locale definition.
11404 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11405 Reference Manual}, for more information on locale names.
11407 @item @code{source}
11408 The name of the source for that locale. This is typically the
11409 @code{@var{language}_@var{territory}} part of the locale name.
11411 @item @code{charset} (default: @code{"UTF-8"})
11412 The ``character set'' or ``code set'' for that locale,
11413 @uref{https://www.iana.org/assignments/character-sets, as defined by
11419 @defvr {Scheme Variable} %default-locale-definitions
11420 A list of commonly used UTF-8 locales, used as the default
11421 value of the @code{locale-definitions} field of @code{operating-system}
11424 @cindex locale name
11425 @cindex normalized codeset in locale names
11426 These locale definitions use the @dfn{normalized codeset} for the part
11427 that follows the dot in the name (@pxref{Using gettextized software,
11428 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11429 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11430 @code{uk_UA.UTF-8}.
11433 @subsection Locale Data Compatibility Considerations
11435 @cindex incompatibility, of locale data
11436 @code{operating-system} declarations provide a @code{locale-libcs} field
11437 to specify the GNU@tie{}libc packages that are used to compile locale
11438 declarations (@pxref{operating-system Reference}). ``Why would I
11439 care?'', you may ask. Well, it turns out that the binary format of
11440 locale data is occasionally incompatible from one libc version to
11443 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11444 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11445 For instance, a program linked against libc version 2.21 is unable to
11446 read locale data produced with libc 2.22; worse, that program
11447 @emph{aborts} instead of simply ignoring the incompatible locale
11448 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11449 the incompatible locale data, which is already an improvement.}.
11450 Similarly, a program linked against libc 2.22 can read most, but not
11451 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11452 data is incompatible); thus calls to @code{setlocale} may fail, but
11453 programs will not abort.
11455 The ``problem'' with Guix is that users have a lot of freedom: They can
11456 choose whether and when to upgrade software in their profiles, and might
11457 be using a libc version different from the one the system administrator
11458 used to build the system-wide locale data.
11460 Fortunately, unprivileged users can also install their own locale data
11461 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11462 @code{GUIX_LOCPATH} and locale packages}).
11464 Still, it is best if the system-wide locale data at
11465 @file{/run/current-system/locale} is built for all the libc versions
11466 actually in use on the system, so that all the programs can access
11467 it---this is especially crucial on a multi-user system. To do that, the
11468 administrator can specify several libc packages in the
11469 @code{locale-libcs} field of @code{operating-system}:
11472 (use-package-modules base)
11476 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11479 This example would lead to a system containing locale definitions for
11480 both libc 2.21 and the current version of libc in
11481 @file{/run/current-system/locale}.
11487 @cindex system services
11488 An important part of preparing an @code{operating-system} declaration is
11489 listing @dfn{system services} and their configuration (@pxref{Using the
11490 Configuration System}). System services are typically daemons launched
11491 when the system boots, or other actions needed at that time---e.g.,
11492 configuring network access.
11494 Guix has a broad definition of ``service'' (@pxref{Service
11495 Composition}), but many services are managed by the GNU@tie{}Shepherd
11496 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11497 command allows you to list the available services, show their status,
11498 start and stop them, or do other specific operations (@pxref{Jump
11499 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11505 The above command, run as @code{root}, lists the currently defined
11506 services. The @command{herd doc} command shows a synopsis of the given
11507 service and its associated actions:
11511 Run libc's name service cache daemon (nscd).
11513 # herd doc nscd action invalidate
11514 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11517 The @command{start}, @command{stop}, and @command{restart} sub-commands
11518 have the effect you would expect. For instance, the commands below stop
11519 the nscd service and restart the Xorg display server:
11523 Service nscd has been stopped.
11524 # herd restart xorg-server
11525 Service xorg-server has been stopped.
11526 Service xorg-server has been started.
11529 The following sections document the available services, starting with
11530 the core services, that may be used in an @code{operating-system}
11534 * Base Services:: Essential system services.
11535 * Scheduled Job Execution:: The mcron service.
11536 * Log Rotation:: The rottlog service.
11537 * Networking Services:: Network setup, SSH daemon, etc.
11538 * X Window:: Graphical display.
11539 * Printing Services:: Local and remote printer support.
11540 * Desktop Services:: D-Bus and desktop services.
11541 * Sound Services:: ALSA and Pulseaudio services.
11542 * Database Services:: SQL databases, key-value stores, etc.
11543 * Mail Services:: IMAP, POP3, SMTP, and all that.
11544 * Messaging Services:: Messaging services.
11545 * Telephony Services:: Telephony services.
11546 * Monitoring Services:: Monitoring services.
11547 * Kerberos Services:: Kerberos services.
11548 * LDAP Services:: LDAP services.
11549 * Web Services:: Web servers.
11550 * Certificate Services:: TLS certificates via Let's Encrypt.
11551 * DNS Services:: DNS daemons.
11552 * VPN Services:: VPN daemons.
11553 * Network File System:: NFS related services.
11554 * Continuous Integration:: The Cuirass service.
11555 * Power Management Services:: Extending battery life.
11556 * Audio Services:: The MPD.
11557 * Virtualization Services:: Virtualization services.
11558 * Version Control Services:: Providing remote access to Git repositories.
11559 * Game Services:: Game servers.
11560 * Miscellaneous Services:: Other services.
11563 @node Base Services
11564 @subsection Base Services
11566 The @code{(gnu services base)} module provides definitions for the basic
11567 services that one expects from the system. The services exported by
11568 this module are listed below.
11570 @defvr {Scheme Variable} %base-services
11571 This variable contains a list of basic services (@pxref{Service Types
11572 and Services}, for more information on service objects) one would
11573 expect from the system: a login service (mingetty) on each tty, syslogd,
11574 the libc name service cache daemon (nscd), the udev device manager, and
11577 This is the default value of the @code{services} field of
11578 @code{operating-system} declarations. Usually, when customizing a
11579 system, you will want to append services to @code{%base-services}, like
11583 (append (list (service avahi-service-type)
11584 (service openssh-service-type))
11589 @defvr {Scheme Variable} special-files-service-type
11590 This is the service that sets up ``special files'' such as
11591 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11593 The value associated with @code{special-files-service-type} services
11594 must be a list of tuples where the first element is the ``special file''
11595 and the second element is its target. By default it is:
11597 @cindex @file{/bin/sh}
11598 @cindex @file{sh}, in @file{/bin}
11600 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11603 @cindex @file{/usr/bin/env}
11604 @cindex @file{env}, in @file{/usr/bin}
11605 If you want to add, say, @code{/usr/bin/env} to your system, you can
11609 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11610 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11613 Since this is part of @code{%base-services}, you can use
11614 @code{modify-services} to customize the set of special files
11615 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11616 to add a special file is @i{via} the @code{extra-special-file} procedure
11620 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11621 Use @var{target} as the ``special file'' @var{file}.
11623 For example, adding the following lines to the @code{services} field of
11624 your operating system declaration leads to a @file{/usr/bin/env}
11628 (extra-special-file "/usr/bin/env"
11629 (file-append coreutils "/bin/env"))
11633 @deffn {Scheme Procedure} host-name-service @var{name}
11634 Return a service that sets the host name to @var{name}.
11637 @deffn {Scheme Procedure} login-service @var{config}
11638 Return a service to run login according to @var{config}, a
11639 @code{<login-configuration>} object, which specifies the message of the day,
11640 among other things.
11643 @deftp {Data Type} login-configuration
11644 This is the data type representing the configuration of login.
11649 @cindex message of the day
11650 A file-like object containing the ``message of the day''.
11652 @item @code{allow-empty-passwords?} (default: @code{#t})
11653 Allow empty passwords by default so that first-time users can log in when
11654 the 'root' account has just been created.
11659 @deffn {Scheme Procedure} mingetty-service @var{config}
11660 Return a service to run mingetty according to @var{config}, a
11661 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11665 @deftp {Data Type} mingetty-configuration
11666 This is the data type representing the configuration of Mingetty, which
11667 provides the default implementation of virtual console log-in.
11672 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11674 @item @code{auto-login} (default: @code{#f})
11675 When true, this field must be a string denoting the user name under
11676 which the system automatically logs in. When it is @code{#f}, a
11677 user name and password must be entered to log in.
11679 @item @code{login-program} (default: @code{#f})
11680 This must be either @code{#f}, in which case the default log-in program
11681 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11682 the name of the log-in program.
11684 @item @code{login-pause?} (default: @code{#f})
11685 When set to @code{#t} in conjunction with @var{auto-login}, the user
11686 will have to press a key before the log-in shell is launched.
11688 @item @code{mingetty} (default: @var{mingetty})
11689 The Mingetty package to use.
11694 @deffn {Scheme Procedure} agetty-service @var{config}
11695 Return a service to run agetty according to @var{config}, an
11696 @code{<agetty-configuration>} object, which specifies the tty to run,
11697 among other things.
11700 @deftp {Data Type} agetty-configuration
11701 This is the data type representing the configuration of agetty, which
11702 implements virtual and serial console log-in. See the @code{agetty(8)}
11703 man page for more information.
11708 The name of the console this agetty runs on, as a string---e.g.,
11709 @code{"ttyS0"}. This argument is optional, it will default to
11710 a reasonable default serial port used by the kernel Linux.
11712 For this, if there is a value for an option @code{agetty.tty} in the kernel
11713 command line, agetty will extract the device name of the serial port
11714 from it and use that.
11716 If not and if there is a value for an option @code{console} with a tty in
11717 the Linux command line, agetty will extract the device name of the
11718 serial port from it and use that.
11720 In both cases, agetty will leave the other serial device settings
11721 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11724 @item @code{baud-rate} (default: @code{#f})
11725 A string containing a comma-separated list of one or more baud rates, in
11728 @item @code{term} (default: @code{#f})
11729 A string containing the value used for the @code{TERM} environment
11732 @item @code{eight-bits?} (default: @code{#f})
11733 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11736 @item @code{auto-login} (default: @code{#f})
11737 When passed a login name, as a string, the specified user will be logged
11738 in automatically without prompting for their login name or password.
11740 @item @code{no-reset?} (default: @code{#f})
11741 When @code{#t}, don't reset terminal cflags (control modes).
11743 @item @code{host} (default: @code{#f})
11744 This accepts a string containing the "login_host", which will be written
11745 into the @file{/var/run/utmpx} file.
11747 @item @code{remote?} (default: @code{#f})
11748 When set to @code{#t} in conjunction with @var{host}, this will add an
11749 @code{-r} fakehost option to the command line of the login program
11750 specified in @var{login-program}.
11752 @item @code{flow-control?} (default: @code{#f})
11753 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11755 @item @code{no-issue?} (default: @code{#f})
11756 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11757 not be displayed before presenting the login prompt.
11759 @item @code{init-string} (default: @code{#f})
11760 This accepts a string that will be sent to the tty or modem before
11761 sending anything else. It can be used to initialize a modem.
11763 @item @code{no-clear?} (default: @code{#f})
11764 When set to @code{#t}, agetty will not clear the screen before showing
11767 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11768 This must be either a gexp denoting the name of a log-in program, or
11769 unset, in which case the default value is the @command{login} from the
11772 @item @code{local-line} (default: @code{#f})
11773 Control the CLOCAL line flag. This accepts one of three symbols as
11774 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11775 the default value chosen by agetty is @code{'auto}.
11777 @item @code{extract-baud?} (default: @code{#f})
11778 When set to @code{#t}, instruct agetty to try to extract the baud rate
11779 from the status messages produced by certain types of modems.
11781 @item @code{skip-login?} (default: @code{#f})
11782 When set to @code{#t}, do not prompt the user for a login name. This
11783 can be used with @var{login-program} field to use non-standard login
11786 @item @code{no-newline?} (default: @code{#f})
11787 When set to @code{#t}, do not print a newline before printing the
11788 @file{/etc/issue} file.
11790 @c Is this dangerous only when used with login-program, or always?
11791 @item @code{login-options} (default: @code{#f})
11792 This option accepts a string containing options that are passed to the
11793 login program. When used with the @var{login-program}, be aware that a
11794 malicious user could try to enter a login name containing embedded
11795 options that could be parsed by the login program.
11797 @item @code{login-pause} (default: @code{#f})
11798 When set to @code{#t}, wait for any key before showing the login prompt.
11799 This can be used in conjunction with @var{auto-login} to save memory by
11800 lazily spawning shells.
11802 @item @code{chroot} (default: @code{#f})
11803 Change root to the specified directory. This option accepts a directory
11806 @item @code{hangup?} (default: @code{#f})
11807 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11808 specified terminal.
11810 @item @code{keep-baud?} (default: @code{#f})
11811 When set to @code{#t}, try to keep the existing baud rate. The baud
11812 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11815 @item @code{timeout} (default: @code{#f})
11816 When set to an integer value, terminate if no user name could be read
11817 within @var{timeout} seconds.
11819 @item @code{detect-case?} (default: @code{#f})
11820 When set to @code{#t}, turn on support for detecting an uppercase-only
11821 terminal. This setting will detect a login name containing only
11822 uppercase letters as indicating an uppercase-only terminal and turn on
11823 some upper-to-lower case conversions. Note that this will not support
11824 Unicode characters.
11826 @item @code{wait-cr?} (default: @code{#f})
11827 When set to @code{#t}, wait for the user or modem to send a
11828 carriage-return or linefeed character before displaying
11829 @file{/etc/issue} or login prompt. This is typically used with the
11830 @var{init-string} option.
11832 @item @code{no-hints?} (default: @code{#f})
11833 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11836 @item @code{no-hostname?} (default: @code{#f})
11837 By default, the hostname is printed. When this option is set to
11838 @code{#t}, no hostname will be shown at all.
11840 @item @code{long-hostname?} (default: @code{#f})
11841 By default, the hostname is only printed until the first dot. When this
11842 option is set to @code{#t}, the fully qualified hostname by
11843 @code{gethostname} or @code{getaddrinfo} is shown.
11845 @item @code{erase-characters} (default: @code{#f})
11846 This option accepts a string of additional characters that should be
11847 interpreted as backspace when the user types their login name.
11849 @item @code{kill-characters} (default: @code{#f})
11850 This option accepts a string that should be interpreted to mean "ignore
11851 all previous characters" (also called a "kill" character) when the user
11852 types their login name.
11854 @item @code{chdir} (default: @code{#f})
11855 This option accepts, as a string, a directory path that will be changed
11858 @item @code{delay} (default: @code{#f})
11859 This options accepts, as an integer, the number of seconds to sleep
11860 before opening the tty and displaying the login prompt.
11862 @item @code{nice} (default: @code{#f})
11863 This option accepts, as an integer, the nice value with which to run the
11864 @command{login} program.
11866 @item @code{extra-options} (default: @code{'()})
11867 This option provides an "escape hatch" for the user to provide arbitrary
11868 command-line arguments to @command{agetty} as a list of strings.
11873 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11874 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11875 according to @var{config}, a @code{<kmscon-configuration>} object, which
11876 specifies the tty to run, among other things.
11879 @deftp {Data Type} kmscon-configuration
11880 This is the data type representing the configuration of Kmscon, which
11881 implements virtual console log-in.
11885 @item @code{virtual-terminal}
11886 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11888 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11889 A gexp denoting the name of the log-in program. The default log-in program is
11890 @command{login} from the Shadow tool suite.
11892 @item @code{login-arguments} (default: @code{'("-p")})
11893 A list of arguments to pass to @command{login}.
11895 @item @code{auto-login} (default: @code{#f})
11896 When passed a login name, as a string, the specified user will be logged
11897 in automatically without prompting for their login name or password.
11899 @item @code{hardware-acceleration?} (default: #f)
11900 Whether to use hardware acceleration.
11902 @item @code{kmscon} (default: @var{kmscon})
11903 The Kmscon package to use.
11908 @cindex name service cache daemon
11910 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11911 [#:name-services '()]
11912 Return a service that runs the libc name service cache daemon (nscd) with the
11913 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11914 Service Switch}, for an example.
11916 For convenience, the Shepherd service for nscd provides the following actions:
11920 @cindex cache invalidation, nscd
11921 @cindex nscd, cache invalidation
11922 This invalidate the given cache. For instance, running:
11925 herd invalidate nscd hosts
11929 invalidates the host name lookup cache of nscd.
11932 Running @command{herd statistics nscd} displays information about nscd usage
11938 @defvr {Scheme Variable} %nscd-default-configuration
11939 This is the default @code{<nscd-configuration>} value (see below) used
11940 by @code{nscd-service}. It uses the caches defined by
11941 @var{%nscd-default-caches}; see below.
11944 @deftp {Data Type} nscd-configuration
11945 This is the data type representing the name service cache daemon (nscd)
11950 @item @code{name-services} (default: @code{'()})
11951 List of packages denoting @dfn{name services} that must be visible to
11952 the nscd---e.g., @code{(list @var{nss-mdns})}.
11954 @item @code{glibc} (default: @var{glibc})
11955 Package object denoting the GNU C Library providing the @command{nscd}
11958 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11959 Name of the nscd log file. This is where debugging output goes when
11960 @code{debug-level} is strictly positive.
11962 @item @code{debug-level} (default: @code{0})
11963 Integer denoting the debugging levels. Higher numbers mean that more
11964 debugging output is logged.
11966 @item @code{caches} (default: @var{%nscd-default-caches})
11967 List of @code{<nscd-cache>} objects denoting things to be cached; see
11973 @deftp {Data Type} nscd-cache
11974 Data type representing a cache database of nscd and its parameters.
11978 @item @code{database}
11979 This is a symbol representing the name of the database to be cached.
11980 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11981 @code{services}, which designate the corresponding NSS database
11982 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11984 @item @code{positive-time-to-live}
11985 @itemx @code{negative-time-to-live} (default: @code{20})
11986 A number representing the number of seconds during which a positive or
11987 negative lookup result remains in cache.
11989 @item @code{check-files?} (default: @code{#t})
11990 Whether to check for updates of the files corresponding to
11993 For instance, when @var{database} is @code{hosts}, setting this flag
11994 instructs nscd to check for updates in @file{/etc/hosts} and to take
11997 @item @code{persistent?} (default: @code{#t})
11998 Whether the cache should be stored persistently on disk.
12000 @item @code{shared?} (default: @code{#t})
12001 Whether the cache should be shared among users.
12003 @item @code{max-database-size} (default: 32@tie{}MiB)
12004 Maximum size in bytes of the database cache.
12006 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12007 @c settings, so leave them out.
12012 @defvr {Scheme Variable} %nscd-default-caches
12013 List of @code{<nscd-cache>} objects used by default by
12014 @code{nscd-configuration} (see above).
12016 It enables persistent and aggressive caching of service and host name
12017 lookups. The latter provides better host name lookup performance,
12018 resilience in the face of unreliable name servers, and also better
12019 privacy---often the result of host name lookups is in local cache, so
12020 external name servers do not even need to be queried.
12023 @anchor{syslog-configuration-type}
12026 @deftp {Data Type} syslog-configuration
12027 This data type represents the configuration of the syslog daemon.
12030 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12031 The syslog daemon to use.
12033 @item @code{config-file} (default: @code{%default-syslog.conf})
12034 The syslog configuration file to use.
12039 @anchor{syslog-service}
12041 @deffn {Scheme Procedure} syslog-service @var{config}
12042 Return a service that runs a syslog daemon according to @var{config}.
12044 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12045 information on the configuration file syntax.
12048 @defvr {Scheme Variable} guix-service-type
12049 This is the type of the service that runs the build daemon,
12050 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12051 @code{guix-configuration} record as described below.
12054 @anchor{guix-configuration-type}
12055 @deftp {Data Type} guix-configuration
12056 This data type represents the configuration of the Guix build daemon.
12057 @xref{Invoking guix-daemon}, for more information.
12060 @item @code{guix} (default: @var{guix})
12061 The Guix package to use.
12063 @item @code{build-group} (default: @code{"guixbuild"})
12064 Name of the group for build user accounts.
12066 @item @code{build-accounts} (default: @code{10})
12067 Number of build user accounts to create.
12069 @item @code{authorize-key?} (default: @code{#t})
12070 @cindex substitutes, authorization thereof
12071 Whether to authorize the substitute keys listed in
12072 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12073 (@pxref{Substitutes}).
12075 @vindex %default-authorized-guix-keys
12076 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12077 The list of authorized key files for archive imports, as a list of
12078 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12079 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12081 @item @code{use-substitutes?} (default: @code{#t})
12082 Whether to use substitutes.
12084 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12085 The list of URLs where to look for substitutes by default.
12087 @item @code{max-silent-time} (default: @code{0})
12088 @itemx @code{timeout} (default: @code{0})
12089 The number of seconds of silence and the number of seconds of activity,
12090 respectively, after which a build process times out. A value of zero
12091 disables the timeout.
12093 @item @code{log-compression} (default: @code{'bzip2})
12094 The type of compression used for build logs---one of @code{gzip},
12095 @code{bzip2}, or @code{none}.
12097 @item @code{extra-options} (default: @code{'()})
12098 List of extra command-line options for @command{guix-daemon}.
12100 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12101 File where @command{guix-daemon}'s standard output and standard error
12104 @item @code{http-proxy} (default: @code{#f})
12105 The HTTP proxy used for downloading fixed-output derivations and
12108 @item @code{tmpdir} (default: @code{#f})
12109 A directory path where the @command{guix-daemon} will perform builds.
12114 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12115 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12116 udev rules can be provided as a list of files through the @var{rules}
12117 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12118 @code{(gnu services base)} simplify the creation of such rule files.
12121 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12122 Return a udev-rule file named @var{file-name} containing the rules
12123 defined by the @var{contents} literal.
12125 In the following example, a rule for a USB device is defined to be
12126 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12127 upon detecting a USB device with a given product identifier.
12130 (define %example-udev-rule
12132 "90-usb-thing.rules"
12133 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12134 "ATTR@{product@}==\"Example\", "
12135 "RUN+=\"/path/to/script\"")))
12138 The @command{herd rules udev} command, as root, returns the name of the
12139 directory containing all the active udev rules.
12142 Here we show how the default @var{udev-service} can be extended with it.
12148 (modify-services %desktop-services
12149 (udev-service-type config =>
12150 (udev-configuration (inherit config)
12151 (rules (append (udev-configuration-rules config)
12152 (list %example-udev-rule))))))))
12155 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12156 Return a udev file named @var{file-name} containing the rules defined
12157 within @var{file}, a file-like object.
12159 The following example showcases how we can use an existing rule file.
12162 (use-modules (guix download) ;for url-fetch
12163 (guix packages) ;for origin
12166 (define %android-udev-rules
12168 "51-android-udev.rules"
12169 (let ((version "20170910"))
12172 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12173 "android-udev-rules/" version "/51-android.rules"))
12175 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12179 Additionally, Guix package definitions can be included in @var{rules} in
12180 order to extend the udev rules with the definitions found under their
12181 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12182 @var{file->udev-rule} example, we could have used the
12183 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12184 packages android)} module.
12186 The following example shows how to use the @var{android-udev-rules}
12187 package so that the Android tool @command{adb} can detect devices
12188 without root privileges. It also details how to create the
12189 @code{adbusers} group, which is required for the proper functioning of
12190 the rules defined within the @var{android-udev-rules} package. To
12191 create such a group, we must define it both as part of the
12192 @var{supplementary-groups} of our @var{user-account} declaration, as
12193 well as in the @var{groups} field of the @var{operating-system} record.
12196 (use-modules (gnu packages android) ;for android-udev-rules
12197 (gnu system shadow) ;for user-group
12202 (users (cons (user-acount
12204 (supplementary-groups
12205 '("adbusers" ;for adb
12206 "wheel" "netdev" "audio" "video"))
12209 (groups (cons (user-group (system? #t) (name "adbusers"))
12215 (modify-services %desktop-services
12218 (udev-configuration (inherit config)
12219 (rules (cons android-udev-rules
12220 (udev-configuration-rules config))))))))
12223 @defvr {Scheme Variable} urandom-seed-service-type
12224 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12225 when rebooting. It also tries to seed @file{/dev/urandom} from
12226 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12230 @defvr {Scheme Variable} %random-seed-file
12231 This is the name of the file where some random bytes are saved by
12232 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12233 It defaults to @file{/var/lib/random-seed}.
12238 @defvr {Scheme Variable} gpm-service-type
12239 This is the type of the service that runs GPM, the @dfn{general-purpose
12240 mouse daemon}, which provides mouse support to the Linux console. GPM
12241 allows users to use the mouse in the console, notably to select, copy,
12244 The value for services of this type must be a @code{gpm-configuration}
12245 (see below). This service is not part of @code{%base-services}.
12248 @deftp {Data Type} gpm-configuration
12249 Data type representing the configuration of GPM.
12252 @item @code{options} (default: @code{%default-gpm-options})
12253 Command-line options passed to @command{gpm}. The default set of
12254 options instruct @command{gpm} to listen to mouse events on
12255 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12258 @item @code{gpm} (default: @code{gpm})
12259 The GPM package to use.
12264 @anchor{guix-publish-service-type}
12265 @deffn {Scheme Variable} guix-publish-service-type
12266 This is the service type for @command{guix publish} (@pxref{Invoking
12267 guix publish}). Its value must be a @code{guix-publish-configuration}
12268 object, as described below.
12270 This assumes that @file{/etc/guix} already contains a signing key pair as
12271 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12272 archive}). If that is not the case, the service will fail to start.
12275 @deftp {Data Type} guix-publish-configuration
12276 Data type representing the configuration of the @code{guix publish}
12280 @item @code{guix} (default: @code{guix})
12281 The Guix package to use.
12283 @item @code{port} (default: @code{80})
12284 The TCP port to listen for connections.
12286 @item @code{host} (default: @code{"localhost"})
12287 The host (and thus, network interface) to listen to. Use
12288 @code{"0.0.0.0"} to listen on all the network interfaces.
12290 @item @code{compression} (default: @code{'(("gzip" 3))})
12291 This is a list of compression method/level tuple used when compressing
12292 substitutes. For example, to compress all substitutes with @emph{both} lzip
12293 at level 7 and gzip at level 9, write:
12296 '(("lzip" 7) ("gzip" 9))
12299 Level 9 achieves the best compression ratio at the expense of increased CPU
12300 usage, whereas level 1 achieves fast compression.
12302 An empty list disables compression altogether.
12304 @item @code{nar-path} (default: @code{"nar"})
12305 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12306 publish, @code{--nar-path}}, for details.
12308 @item @code{cache} (default: @code{#f})
12309 When it is @code{#f}, disable caching and instead generate archives on
12310 demand. Otherwise, this should be the name of a directory---e.g.,
12311 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12312 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12313 @option{--cache}}, for more information on the tradeoffs involved.
12315 @item @code{workers} (default: @code{#f})
12316 When it is an integer, this is the number of worker threads used for
12317 caching; when @code{#f}, the number of processors is used.
12318 @xref{Invoking guix publish, @option{--workers}}, for more information.
12320 @item @code{ttl} (default: @code{#f})
12321 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12322 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12323 for more information.
12327 @anchor{rngd-service}
12328 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12329 [#:device "/dev/hwrng"]
12330 Return a service that runs the @command{rngd} program from @var{rng-tools}
12331 to add @var{device} to the kernel's entropy pool. The service will fail if
12332 @var{device} does not exist.
12335 @anchor{pam-limits-service}
12336 @cindex session limits
12341 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12343 Return a service that installs a configuration file for the
12344 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12345 @code{pam_limits} module}. The procedure optionally takes a list of
12346 @code{pam-limits-entry} values, which can be used to specify
12347 @code{ulimit} limits and nice priority limits to user sessions.
12349 The following limits definition sets two hard and soft limits for all
12350 login sessions of users in the @code{realtime} group:
12353 (pam-limits-service
12355 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12356 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12359 The first entry increases the maximum realtime priority for
12360 non-privileged processes; the second entry lifts any restriction of the
12361 maximum address space that can be locked in memory. These settings are
12362 commonly used for real-time audio systems.
12365 @node Scheduled Job Execution
12366 @subsection Scheduled Job Execution
12370 @cindex scheduling jobs
12371 The @code{(gnu services mcron)} module provides an interface to
12372 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12373 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12374 Unix @command{cron} daemon; the main difference is that it is
12375 implemented in Guile Scheme, which provides a lot of flexibility when
12376 specifying the scheduling of jobs and their actions.
12378 The example below defines an operating system that runs the
12379 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12380 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12381 well as the @command{mkid} command on behalf of an unprivileged user
12382 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12383 gexps to introduce job definitions that are passed to mcron
12384 (@pxref{G-Expressions}).
12387 (use-modules (guix) (gnu) (gnu services mcron))
12388 (use-package-modules base idutils)
12390 (define updatedb-job
12391 ;; Run 'updatedb' at 3AM every day. Here we write the
12392 ;; job's action as a Scheme procedure.
12393 #~(job '(next-hour '(3))
12395 (execl (string-append #$findutils "/bin/updatedb")
12397 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12399 (define garbage-collector-job
12400 ;; Collect garbage 5 minutes after midnight every day.
12401 ;; The job's action is a shell command.
12402 #~(job "5 0 * * *" ;Vixie cron syntax
12405 (define idutils-job
12406 ;; Update the index database as user "charlie" at 12:15PM
12407 ;; and 19:15PM. This runs from the user's home directory.
12408 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12409 (string-append #$idutils "/bin/mkid src")
12414 (services (cons (service mcron-service-type
12415 (mcron-configuration
12416 (jobs (list garbage-collector-job
12422 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12423 for more information on mcron job specifications. Below is the
12424 reference of the mcron service.
12426 On a running system, you can use the @code{schedule} action of the service to
12427 visualize the mcron jobs that will be executed next:
12430 # herd schedule mcron
12434 The example above lists the next five tasks that will be executed, but you can
12435 also specify the number of tasks to display:
12438 # herd schedule mcron 10
12441 @defvr {Scheme Variable} mcron-service-type
12442 This is the type of the @code{mcron} service, whose value is an
12443 @code{mcron-configuration} object.
12445 This service type can be the target of a service extension that provides
12446 it additional job specifications (@pxref{Service Composition}). In
12447 other words, it is possible to define services that provide additional
12451 @deftp {Data Type} mcron-configuration
12452 Data type representing the configuration of mcron.
12455 @item @code{mcron} (default: @var{mcron})
12456 The mcron package to use.
12459 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12460 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12461 specifications,, mcron, GNU@tie{}mcron}).
12467 @subsection Log Rotation
12470 @cindex log rotation
12472 Log files such as those found in @file{/var/log} tend to grow endlessly,
12473 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12474 their contents in separate files, possibly compressed. The @code{(gnu
12475 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12476 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12478 The example below defines an operating system that provides log rotation
12479 with the default settings, for commonly encountered log files.
12482 (use-modules (guix) (gnu))
12483 (use-service-modules admin mcron)
12484 (use-package-modules base idutils)
12488 (services (cons (service rottlog-service-type)
12492 @defvr {Scheme Variable} rottlog-service-type
12493 This is the type of the Rottlog service, whose value is a
12494 @code{rottlog-configuration} object.
12496 Other services can extend this one with new @code{log-rotation} objects
12497 (see below), thereby augmenting the set of files to be rotated.
12499 This service type can define mcron jobs (@pxref{Scheduled Job
12500 Execution}) to run the rottlog service.
12503 @deftp {Data Type} rottlog-configuration
12504 Data type representing the configuration of rottlog.
12507 @item @code{rottlog} (default: @code{rottlog})
12508 The Rottlog package to use.
12510 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12511 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12512 rottlog, GNU Rot[t]log Manual}).
12514 @item @code{rotations} (default: @code{%default-rotations})
12515 A list of @code{log-rotation} objects as defined below.
12518 This is a list of gexps where each gexp corresponds to an mcron job
12519 specification (@pxref{Scheduled Job Execution}).
12523 @deftp {Data Type} log-rotation
12524 Data type representing the rotation of a group of log files.
12526 Taking an example from the Rottlog manual (@pxref{Period Related File
12527 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12533 (files '("/var/log/apache/*"))
12534 (options '("storedir apache-archives"
12540 The list of fields is as follows:
12543 @item @code{frequency} (default: @code{'weekly})
12544 The log rotation frequency, a symbol.
12547 The list of files or file glob patterns to rotate.
12549 @item @code{options} (default: @code{'()})
12550 The list of rottlog options for this rotation (@pxref{Configuration
12551 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12553 @item @code{post-rotate} (default: @code{#f})
12554 Either @code{#f} or a gexp to execute once the rotation has completed.
12558 @defvr {Scheme Variable} %default-rotations
12559 Specifies weekly rotation of @var{%rotated-files} and
12560 a couple of other files.
12563 @defvr {Scheme Variable} %rotated-files
12564 The list of syslog-controlled files to be rotated. By default it is:
12565 @code{'("/var/log/messages" "/var/log/secure")}.
12568 @node Networking Services
12569 @subsection Networking Services
12571 The @code{(gnu services networking)} module provides services to configure
12572 the network interface.
12574 @cindex DHCP, networking service
12575 @defvr {Scheme Variable} dhcp-client-service-type
12576 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12577 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12578 is the DHCP client package to use, @code{isc-dhcp} by default.
12581 @deffn {Scheme Procedure} dhcpd-service-type
12582 This type defines a service that runs a DHCP daemon. To create a
12583 service of this type, you must supply a @code{<dhcpd-configuration>}.
12587 (service dhcpd-service-type
12588 (dhcpd-configuration
12589 (config-file (local-file "my-dhcpd.conf"))
12590 (interfaces '("enp0s25"))))
12594 @deftp {Data Type} dhcpd-configuration
12596 @item @code{package} (default: @code{isc-dhcp})
12597 The package that provides the DHCP daemon. This package is expected to
12598 provide the daemon at @file{sbin/dhcpd} relative to its output
12599 directory. The default package is the
12600 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
12601 @item @code{config-file} (default: @code{#f})
12602 The configuration file to use. This is required. It will be passed to
12603 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12604 object (@pxref{G-Expressions, file-like objects}). See @code{man
12605 dhcpd.conf} for details on the configuration file syntax.
12606 @item @code{version} (default: @code{"4"})
12607 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12608 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12609 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12611 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12612 The run directory to use. At service activation time, this directory
12613 will be created if it does not exist.
12614 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12615 The PID file to use. This corresponds to the @code{-pf} option of
12616 @code{dhcpd}. See @code{man dhcpd} for details.
12617 @item @code{interfaces} (default: @code{'()})
12618 The names of the network interfaces on which dhcpd should listen for
12619 broadcasts. If this list is not empty, then its elements (which must be
12620 strings) will be appended to the @code{dhcpd} invocation when starting
12621 the daemon. It may not be necessary to explicitly specify any
12622 interfaces here; see @code{man dhcpd} for details.
12626 @defvr {Scheme Variable} static-networking-service-type
12627 This is the type for statically-configured network interfaces.
12628 @c TODO Document <static-networking> data structures.
12631 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12632 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12633 [#:requirement @code{'(udev)}]
12634 Return a service that starts @var{interface} with address @var{ip}. If
12635 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12636 it must be a string specifying the default network gateway. @var{requirement}
12637 can be used to declare a dependency on another service before configuring the
12640 This procedure can be called several times, one for each network
12641 interface of interest. Behind the scenes what it does is extend
12642 @code{static-networking-service-type} with additional network interfaces
12648 (static-networking-service "eno1" "192.168.1.82"
12649 #:gateway "192.168.1.2"
12650 #:name-servers '("192.168.1.2"))
12657 @cindex network management
12658 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12659 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12660 management daemon that aims to simplify wired and wireless networking.
12662 This service adds the @var{wicd} package to the global profile, providing
12663 several commands to interact with the daemon and configure networking:
12664 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12665 and @command{wicd-curses} user interfaces.
12668 @cindex ModemManager
12670 @defvr {Scheme Variable} modem-manager-service-type
12671 This is the service type for the
12672 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12673 service. The value for this service type is a
12674 @code{modem-manager-configuration} record.
12676 This service is part of @code{%desktop-services} (@pxref{Desktop
12680 @deftp {Data Type} modem-manager-configuration
12681 Data type representing the configuration of ModemManager.
12684 @item @code{modem-manager} (default: @code{modem-manager})
12685 The ModemManager package to use.
12690 @cindex USB_ModeSwitch
12691 @cindex Modeswitching
12693 @defvr {Scheme Variable} usb-modeswitch-service-type
12694 This is the service type for the
12695 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
12696 value for this service type is a @code{usb-modeswitch-configuration} record.
12698 When plugged in, some USB modems (and other USB devices) initially present
12699 themselves as a read-only storage medium and not as a modem. They need to be
12700 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
12701 installs udev rules to automatically modeswitch these devices when they are
12704 This service is part of @code{%desktop-services} (@pxref{Desktop
12708 @deftp {Data Type} usb-modeswitch-configuration
12709 Data type representing the configuration of USB_ModeSwitch.
12712 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
12713 The USB_ModeSwitch package providing the binaries for modeswitching.
12715 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
12716 The package providing the device data and udev rules file used by
12719 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
12720 Which config file to use for the USB_ModeSwitch dispatcher. By default the
12721 config file shipped with USB_ModeSwitch is used which disables logging to
12722 @file{/var/log} among other default settings. If set to @code{#f}, no config
12728 @cindex NetworkManager
12730 @defvr {Scheme Variable} network-manager-service-type
12731 This is the service type for the
12732 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12733 service. The value for this service type is a
12734 @code{network-manager-configuration} record.
12736 This service is part of @code{%desktop-services} (@pxref{Desktop
12740 @deftp {Data Type} network-manager-configuration
12741 Data type representing the configuration of NetworkManager.
12744 @item @code{network-manager} (default: @code{network-manager})
12745 The NetworkManager package to use.
12747 @item @code{dns} (default: @code{"default"})
12748 Processing mode for DNS, which affects how NetworkManager uses the
12749 @code{resolv.conf} configuration file.
12753 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12754 provided by currently active connections.
12757 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
12758 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
12759 then update @code{resolv.conf} to point to the local nameserver.
12761 With this setting, you can share your network connection. For example when
12762 you want to share your network connection to another laptop @i{via} an
12763 Ethernet cable, you can open @command{nm-connection-editor} and configure the
12764 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
12765 and reestablish the connection (or reboot).
12767 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
12768 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
12769 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
12770 browser on your host system, or connect to the VM @i{via} SSH
12771 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
12772 host-to-guest connection, run this command once:
12775 nmcli connection add type tun \
12776 connection.interface-name tap0 \
12777 tun.mode tap tun.owner $(id -u) \
12778 ipv4.method shared \
12779 ipv4.addresses 172.28.112.1/24
12782 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
12783 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
12784 @command{qemu-system-...}.
12787 NetworkManager will not modify @code{resolv.conf}.
12790 @item @code{vpn-plugins} (default: @code{'()})
12791 This is the list of available plugins for virtual private networks
12792 (VPNs). An example of this is the @code{network-manager-openvpn}
12793 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12799 @deffn {Scheme Variable} connman-service-type
12800 This is the service type to run @url{https://01.org/connman,Connman},
12801 a network connection manager.
12803 Its value must be an
12804 @code{connman-configuration} record as in this example:
12807 (service connman-service-type
12808 (connman-configuration
12809 (disable-vpn? #t)))
12812 See below for details about @code{connman-configuration}.
12815 @deftp {Data Type} connman-configuration
12816 Data Type representing the configuration of connman.
12819 @item @code{connman} (default: @var{connman})
12820 The connman package to use.
12822 @item @code{disable-vpn?} (default: @code{#f})
12823 When true, disable connman's vpn plugin.
12827 @cindex WPA Supplicant
12828 @defvr {Scheme Variable} wpa-supplicant-service-type
12829 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12830 supplicant}, an authentication daemon required to authenticate against
12831 encrypted WiFi or ethernet networks.
12834 @deftp {Data Type} wpa-supplicant-configuration
12835 Data type representing the configuration of WPA Supplicant.
12837 It takes the following parameters:
12840 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12841 The WPA Supplicant package to use.
12843 @item @code{dbus?} (default: @code{#t})
12844 Whether to listen for requests on D-Bus.
12846 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12847 Where to store the PID file.
12849 @item @code{interface} (default: @code{#f})
12850 If this is set, it must specify the name of a network interface that
12851 WPA supplicant will control.
12853 @item @code{config-file} (default: @code{#f})
12854 Optional configuration file to use.
12856 @item @code{extra-options} (default: @code{'()})
12857 List of additional command-line arguments to pass to the daemon.
12862 @defvr {Scheme Variable} iptables-service-type
12863 This is the service type to set up an iptables configuration. iptables is a
12864 packet filtering framework supported by the Linux kernel. This service
12865 supports configuring iptables for both IPv4 and IPv6. A simple example
12866 configuration rejecting all incoming connections except those to the ssh port
12870 (service iptables-service-type
12871 (iptables-configuration
12872 (ipv4-rules (plain-file "iptables.rules" "*filter
12876 -A INPUT -p tcp --dport 22 -j ACCEPT
12877 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12880 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12884 -A INPUT -p tcp --dport 22 -j ACCEPT
12885 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12891 @deftp {Data Type} iptables-configuration
12892 The data type representing the configuration of iptables.
12895 @item @code{iptables} (default: @code{iptables})
12896 The iptables package that provides @code{iptables-restore} and
12897 @code{ip6tables-restore}.
12898 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12899 The iptables rules to use. It will be passed to @code{iptables-restore}.
12900 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12902 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12903 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12904 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12909 @cindex NTP (Network Time Protocol), service
12910 @cindex real time clock
12911 @defvr {Scheme Variable} ntp-service-type
12912 This is the type of the service running the @uref{http://www.ntp.org,
12913 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12914 system clock synchronized with that of the specified NTP servers.
12916 The value of this service is an @code{ntpd-configuration} object, as described
12920 @deftp {Data Type} ntp-configuration
12921 This is the data type for the NTP service configuration.
12924 @item @code{servers} (default: @code{%ntp-servers})
12925 This is the list of servers (host names) with which @command{ntpd} will be
12928 @item @code{allow-large-adjustment?} (default: @code{#f})
12929 This determines whether @command{ntpd} is allowed to make an initial
12930 adjustment of more than 1,000 seconds.
12932 @item @code{ntp} (default: @code{ntp})
12933 The NTP package to use.
12937 @defvr {Scheme Variable} %ntp-servers
12938 List of host names used as the default NTP servers. These are servers of the
12939 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12943 @deffn {Scheme Procedure} openntpd-service-type
12944 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12945 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12946 clock synchronized with that of the given servers.
12950 openntpd-service-type
12951 (openntpd-configuration
12952 (listen-on '("127.0.0.1" "::1"))
12953 (sensor '("udcf0 correction 70000"))
12954 (constraint-from '("www.gnu.org"))
12955 (constraints-from '("https://www.google.com/"))
12956 (allow-large-adjustment? #t)))
12961 @deftp {Data Type} openntpd-configuration
12963 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12964 The openntpd executable to use.
12965 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12966 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12967 @item @code{query-from} (default: @code{'()})
12968 A list of local IP address the ntpd daemon should use for outgoing queries.
12969 @item @code{sensor} (default: @code{'()})
12970 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12971 will listen to each sensor that actually exists and ignore non-existent ones.
12972 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12974 @item @code{server} (default: @var{%ntp-servers})
12975 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12976 @item @code{servers} (default: @code{'()})
12977 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12978 @item @code{constraint-from} (default: @code{'()})
12979 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12980 This time information is not used for precision but acts as an authenticated
12981 constraint, thereby reducing the impact of unauthenticated NTP
12982 man-in-the-middle attacks.
12983 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12985 @item @code{constraints-from} (default: @code{'()})
12986 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12987 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12988 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12989 @item @code{allow-large-adjustment?} (default: @code{#f})
12990 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12996 @deffn {Scheme variable} inetd-service-type
12997 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12998 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12999 connections on internet sockets, and lazily starts the specified server
13000 program when a connection is made on one of these sockets.
13002 The value of this service is an @code{inetd-configuration} object. The
13003 following example configures the @command{inetd} daemon to provide the
13004 built-in @command{echo} service, as well as an smtp service which
13005 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13006 gateway @code{hostname}:
13011 (inetd-configuration
13015 (socket-type 'stream)
13022 (socket-type 'stream)
13026 (program (file-append openssh "/bin/ssh"))
13028 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13029 "-W" "smtp-server:25" "user@@hostname")))))
13032 See below for more details about @code{inetd-configuration}.
13035 @deftp {Data Type} inetd-configuration
13036 Data type representing the configuration of @command{inetd}.
13039 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13040 The @command{inetd} executable to use.
13042 @item @code{entries} (default: @code{'()})
13043 A list of @command{inetd} service entries. Each entry should be created
13044 by the @code{inetd-entry} constructor.
13048 @deftp {Data Type} inetd-entry
13049 Data type representing an entry in the @command{inetd} configuration.
13050 Each entry corresponds to a socket where @command{inetd} will listen for
13054 @item @code{node} (default: @code{#f})
13055 Optional string, a comma-separated list of local addresses
13056 @command{inetd} should use when listening for this service.
13057 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13058 description of all options.
13060 A string, the name must correspond to an entry in @code{/etc/services}.
13061 @item @code{socket-type}
13062 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13064 @item @code{protocol}
13065 A string, must correspond to an entry in @code{/etc/protocols}.
13066 @item @code{wait?} (default: @code{#t})
13067 Whether @command{inetd} should wait for the server to exit before
13068 listening to new service requests.
13070 A string containing the user (and, optionally, group) name of the user
13071 as whom the server should run. The group name can be specified in a
13072 suffix, separated by a colon or period, i.e.@: @code{"user"},
13073 @code{"user:group"} or @code{"user.group"}.
13074 @item @code{program} (default: @code{"internal"})
13075 The server program which will serve the requests, or @code{"internal"}
13076 if @command{inetd} should use a built-in service.
13077 @item @code{arguments} (default: @code{'()})
13078 A list strings or file-like objects, which are the server program's
13079 arguments, starting with the zeroth argument, i.e.@: the name of the
13080 program itself. For @command{inetd}'s internal services, this entry
13081 must be @code{'()} or @code{'("internal")}.
13084 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13085 detailed discussion of each configuration field.
13089 @defvr {Scheme Variable} tor-service-type
13090 This is the type for a service that runs the @uref{https://torproject.org,
13091 Tor} anonymous networking daemon. The service is configured using a
13092 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13093 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13097 @deftp {Data Type} tor-configuration
13099 @item @code{tor} (default: @code{tor})
13100 The package that provides the Tor daemon. This package is expected to provide
13101 the daemon at @file{bin/tor} relative to its output directory. The default
13102 package is the @uref{https://www.torproject.org, Tor Project's}
13105 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13106 The configuration file to use. It will be appended to a default configuration
13107 file, and the final configuration file will be passed to @code{tor} via its
13108 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13109 file-like objects}). See @code{man tor} for details on the configuration file
13112 @item @code{hidden-services} (default: @code{'()})
13113 The list of @code{<hidden-service>} records to use. For any hidden service
13114 you include in this list, appropriate configuration to enable the hidden
13115 service will be automatically added to the default configuration file. You
13116 may conveniently create @code{<hidden-service>} records using the
13117 @code{tor-hidden-service} procedure described below.
13119 @item @code{socks-socket-type} (default: @code{'tcp})
13120 The default socket type that Tor should use for its SOCKS socket. This must
13121 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13122 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13123 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13124 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13127 If you want to customize the SOCKS socket in more detail, leave
13128 @code{socks-socket-type} at its default value of @code{'tcp} and use
13129 @code{config-file} to override the default by providing your own
13130 @code{SocksPort} option.
13134 @cindex hidden service
13135 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13136 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13137 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13140 '((22 "127.0.0.1:22")
13141 (80 "127.0.0.1:8080"))
13144 In this example, port 22 of the hidden service is mapped to local port 22, and
13145 port 80 is mapped to local port 8080.
13147 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13148 the @file{hostname} file contains the @code{.onion} host name for the hidden
13151 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13152 project's documentation} for more information.
13155 The @code{(gnu services rsync)} module provides the following services:
13157 You might want an rsync daemon if you have files that you want available
13158 so anyone (or just yourself) can download existing files or upload new
13161 @deffn {Scheme Variable} rsync-service-type
13162 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13163 The value for this service type is a
13164 @command{rsync-configuration} record as in this example:
13167 (service rsync-service-type)
13170 See below for details about @code{rsync-configuration}.
13173 @deftp {Data Type} rsync-configuration
13174 Data type representing the configuration for @code{rsync-service}.
13177 @item @code{package} (default: @var{rsync})
13178 @code{rsync} package to use.
13180 @item @code{port-number} (default: @code{873})
13181 TCP port on which @command{rsync} listens for incoming connections. If port
13182 is less than @code{1024} @command{rsync} needs to be started as the
13183 @code{root} user and group.
13185 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13186 Name of the file where @command{rsync} writes its PID.
13188 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13189 Name of the file where @command{rsync} writes its lock file.
13191 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13192 Name of the file where @command{rsync} writes its log file.
13194 @item @code{use-chroot?} (default: @var{#t})
13195 Whether to use chroot for @command{rsync} shared directory.
13197 @item @code{share-path} (default: @file{/srv/rsync})
13198 Location of the @command{rsync} shared directory.
13200 @item @code{share-comment} (default: @code{"Rsync share"})
13201 Comment of the @command{rsync} shared directory.
13203 @item @code{read-only?} (default: @var{#f})
13204 Read-write permissions to shared directory.
13206 @item @code{timeout} (default: @code{300})
13207 I/O timeout in seconds.
13209 @item @code{user} (default: @var{"root"})
13210 Owner of the @code{rsync} process.
13212 @item @code{group} (default: @var{"root"})
13213 Group of the @code{rsync} process.
13215 @item @code{uid} (default: @var{"rsyncd"})
13216 User name or user ID that file transfers to and from that module should take
13217 place as when the daemon was run as @code{root}.
13219 @item @code{gid} (default: @var{"rsyncd"})
13220 Group name or group ID that will be used when accessing the module.
13225 Furthermore, @code{(gnu services ssh)} provides the following services.
13229 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13230 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13231 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13232 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13233 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13234 [#:public-key-authentication? #t] [#:initialize? #t]
13235 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13236 @var{host-key} must designate a file containing the host key, and readable
13239 When @var{daemonic?} is true, @command{lshd} will detach from the
13240 controlling terminal and log its output to syslogd, unless one sets
13241 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13242 depend on existence of syslogd service. When @var{pid-file?} is true,
13243 @command{lshd} writes its PID to the file called @var{pid-file}.
13245 When @var{initialize?} is true, automatically create the seed and host key
13246 upon service activation if they do not exist yet. This may take long and
13247 require interaction.
13249 When @var{initialize?} is false, it is up to the user to initialize the
13250 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13251 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13252 basics,,, lsh, LSH Manual}).
13254 When @var{interfaces} is empty, lshd listens for connections on all the
13255 network interfaces; otherwise, @var{interfaces} must be a list of host names
13258 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13259 passwords, and @var{root-login?} specifies whether to accept log-ins as
13262 The other options should be self-descriptive.
13267 @deffn {Scheme Variable} openssh-service-type
13268 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13269 shell daemon, @command{sshd}. Its value must be an
13270 @code{openssh-configuration} record as in this example:
13273 (service openssh-service-type
13274 (openssh-configuration
13275 (x11-forwarding? #t)
13276 (permit-root-login 'without-password)
13278 `(("alice" ,(local-file "alice.pub"))
13279 ("bob" ,(local-file "bob.pub"))))))
13282 See below for details about @code{openssh-configuration}.
13284 This service can be extended with extra authorized keys, as in this
13288 (service-extension openssh-service-type
13289 (const `(("charlie"
13290 ,(local-file "charlie.pub")))))
13294 @deftp {Data Type} openssh-configuration
13295 This is the configuration record for OpenSSH's @command{sshd}.
13298 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13299 Name of the file where @command{sshd} writes its PID.
13301 @item @code{port-number} (default: @code{22})
13302 TCP port on which @command{sshd} listens for incoming connections.
13304 @item @code{permit-root-login} (default: @code{#f})
13305 This field determines whether and when to allow logins as root. If
13306 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13307 If it's the symbol @code{'without-password}, then root logins are
13308 permitted but not with password-based authentication.
13310 @item @code{allow-empty-passwords?} (default: @code{#f})
13311 When true, users with empty passwords may log in. When false, they may
13314 @item @code{password-authentication?} (default: @code{#t})
13315 When true, users may log in with their password. When false, they have
13316 other authentication methods.
13318 @item @code{public-key-authentication?} (default: @code{#t})
13319 When true, users may log in using public key authentication. When
13320 false, users have to use other authentication method.
13322 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13323 This is used only by protocol version 2.
13325 @item @code{x11-forwarding?} (default: @code{#f})
13326 When true, forwarding of X11 graphical client connections is
13327 enabled---in other words, @command{ssh} options @option{-X} and
13328 @option{-Y} will work.
13330 @item @code{allow-agent-forwarding?} (default: @code{#t})
13331 Whether to allow agent forwarding.
13333 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13334 Whether to allow TCP forwarding.
13336 @item @code{gateway-ports?} (default: @code{#f})
13337 Whether to allow gateway ports.
13339 @item @code{challenge-response-authentication?} (default: @code{#f})
13340 Specifies whether challenge response authentication is allowed (e.g.@: via
13343 @item @code{use-pam?} (default: @code{#t})
13344 Enables the Pluggable Authentication Module interface. If set to
13345 @code{#t}, this will enable PAM authentication using
13346 @code{challenge-response-authentication?} and
13347 @code{password-authentication?}, in addition to PAM account and session
13348 module processing for all authentication types.
13350 Because PAM challenge response authentication usually serves an
13351 equivalent role to password authentication, you should disable either
13352 @code{challenge-response-authentication?} or
13353 @code{password-authentication?}.
13355 @item @code{print-last-log?} (default: @code{#t})
13356 Specifies whether @command{sshd} should print the date and time of the
13357 last user login when a user logs in interactively.
13359 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13360 Configures external subsystems (e.g.@: file transfer daemon).
13362 This is a list of two-element lists, each of which containing the
13363 subsystem name and a command (with optional arguments) to execute upon
13366 The command @command{internal-sftp} implements an in-process SFTP
13367 server. Alternately, one can specify the @command{sftp-server} command:
13369 (service openssh-service-type
13370 (openssh-configuration
13372 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13375 @item @code{accepted-environment} (default: @code{'()})
13376 List of strings describing which environment variables may be exported.
13378 Each string gets on its own line. See the @code{AcceptEnv} option in
13379 @code{man sshd_config}.
13381 This example allows ssh-clients to export the @code{COLORTERM} variable.
13382 It is set by terminal emulators, which support colors. You can use it in
13383 your shell's ressource file to enable colors for the prompt and commands
13384 if this variable is set.
13387 (service openssh-service-type
13388 (openssh-configuration
13389 (accepted-environment '("COLORTERM"))))
13392 @item @code{authorized-keys} (default: @code{'()})
13393 @cindex authorized keys, SSH
13394 @cindex SSH authorized keys
13395 This is the list of authorized keys. Each element of the list is a user
13396 name followed by one or more file-like objects that represent SSH public
13400 (openssh-configuration
13402 `(("rekado" ,(local-file "rekado.pub"))
13403 ("chris" ,(local-file "chris.pub"))
13404 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13408 registers the specified public keys for user accounts @code{rekado},
13409 @code{chris}, and @code{root}.
13411 Additional authorized keys can be specified @i{via}
13412 @code{service-extension}.
13414 Note that this does @emph{not} interfere with the use of
13415 @file{~/.ssh/authorized_keys}.
13417 @item @code{log-level} (default: @code{'info})
13418 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13419 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13420 page for @file{sshd_config} for the full list of level names.
13422 @item @code{extra-content} (default: @code{""})
13423 This field can be used to append arbitrary text to the configuration file. It
13424 is especially useful for elaborate configurations that cannot be expressed
13425 otherwise. This configuration, for example, would generally disable root
13426 logins, but permit them from one specific IP address:
13429 (openssh-configuration
13431 Match Address 192.168.0.1
13432 PermitRootLogin yes"))
13438 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13439 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13440 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13443 For example, to specify a Dropbear service listening on port 1234, add
13444 this call to the operating system's @code{services} field:
13447 (dropbear-service (dropbear-configuration
13448 (port-number 1234)))
13452 @deftp {Data Type} dropbear-configuration
13453 This data type represents the configuration of a Dropbear SSH daemon.
13456 @item @code{dropbear} (default: @var{dropbear})
13457 The Dropbear package to use.
13459 @item @code{port-number} (default: 22)
13460 The TCP port where the daemon waits for incoming connections.
13462 @item @code{syslog-output?} (default: @code{#t})
13463 Whether to enable syslog output.
13465 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13466 File name of the daemon's PID file.
13468 @item @code{root-login?} (default: @code{#f})
13469 Whether to allow @code{root} logins.
13471 @item @code{allow-empty-passwords?} (default: @code{#f})
13472 Whether to allow empty passwords.
13474 @item @code{password-authentication?} (default: @code{#t})
13475 Whether to enable password-based authentication.
13479 @defvr {Scheme Variable} %facebook-host-aliases
13480 This variable contains a string for use in @file{/etc/hosts}
13481 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13482 line contains a entry that maps a known server name of the Facebook
13483 on-line service---e.g., @code{www.facebook.com}---to the local
13484 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13486 This variable is typically used in the @code{hosts-file} field of an
13487 @code{operating-system} declaration (@pxref{operating-system Reference,
13488 @file{/etc/hosts}}):
13491 (use-modules (gnu) (guix))
13494 (host-name "mymachine")
13497 ;; Create a /etc/hosts file with aliases for "localhost"
13498 ;; and "mymachine", as well as for Facebook servers.
13499 (plain-file "hosts"
13500 (string-append (local-host-aliases host-name)
13501 %facebook-host-aliases))))
13504 This mechanism can prevent programs running locally, such as Web
13505 browsers, from accessing Facebook.
13508 The @code{(gnu services avahi)} provides the following definition.
13510 @defvr {Scheme Variable} avahi-service-type
13511 This is the service that runs @command{avahi-daemon}, a system-wide
13512 mDNS/DNS-SD responder that allows for service discovery and
13513 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13514 Its value must be a @code{zero-configuration} record---see below.
13516 This service extends the name service cache daemon (nscd) so that it can
13517 resolve @code{.local} host names using
13518 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13519 Service Switch}, for information on host name resolution.
13521 Additionally, add the @var{avahi} package to the system profile so that
13522 commands such as @command{avahi-browse} are directly usable.
13525 @deftp {Data Type} avahi-configuration
13526 Data type representation the configuration for Avahi.
13530 @item @code{host-name} (default: @code{#f})
13531 If different from @code{#f}, use that as the host name to
13532 publish for this machine; otherwise, use the machine's actual host name.
13534 @item @code{publish?} (default: @code{#t})
13535 When true, allow host names and services to be published (broadcast) over the
13538 @item @code{publish-workstation?} (default: @code{#t})
13539 When true, @command{avahi-daemon} publishes the machine's host name and IP
13540 address via mDNS on the local network. To view the host names published on
13541 your local network, you can run:
13544 avahi-browse _workstation._tcp
13547 @item @code{wide-area?} (default: @code{#f})
13548 When true, DNS-SD over unicast DNS is enabled.
13550 @item @code{ipv4?} (default: @code{#t})
13551 @itemx @code{ipv6?} (default: @code{#t})
13552 These fields determine whether to use IPv4/IPv6 sockets.
13554 @item @code{domains-to-browse} (default: @code{'()})
13555 This is a list of domains to browse.
13559 @deffn {Scheme Variable} openvswitch-service-type
13560 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
13561 service, whose value should be an @code{openvswitch-configuration}
13565 @deftp {Data Type} openvswitch-configuration
13566 Data type representing the configuration of Open vSwitch, a multilayer
13567 virtual switch which is designed to enable massive network automation
13568 through programmatic extension.
13571 @item @code{package} (default: @var{openvswitch})
13572 Package object of the Open vSwitch.
13578 @subsection X Window
13581 @cindex X Window System
13582 @cindex login manager
13583 Support for the X Window graphical display system---specifically
13584 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13585 there is no @code{xorg-service} procedure. Instead, the X server is
13586 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13589 @cindex GNOME, login manager
13590 GDM of course allows users to log in into window managers and desktop
13591 environments other than GNOME; for those using GNOME, GDM is required for
13592 features such as automatic screen locking.
13594 @cindex window manager
13595 To use X11, you must install at least one @dfn{window manager}---for
13596 example the @code{windowmaker} or @code{openbox} packages---preferably
13597 by adding it to the @code{packages} field of your operating system
13598 definition (@pxref{operating-system Reference, system-wide packages}).
13600 @defvr {Scheme Variable} gdm-service-type
13601 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13602 Desktop Manager} (GDM), a program that manages graphical display servers and
13603 handles graphical user logins. Its value must be a @code{gdm-configuration}
13606 @cindex session types (X11)
13607 @cindex X11 session types
13608 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13609 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13610 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13611 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13612 set of packages automatically makes them available at the log-in screen.
13614 In addition, @file{~/.xsession} files are honored. When available,
13615 @file{~/.xsession} must be an executable that starts a window manager
13616 and/or other X clients.
13619 @deftp {Data Type} gdm-configuration
13621 @item @code{auto-login?} (default: @code{#f})
13622 @itemx @code{default-user} (default: @code{#f})
13623 When @code{auto-login?} is false, GDM presents a log-in screen.
13625 When @code{auto-login?} is true, GDM logs in directly as
13626 @code{default-user}.
13628 @item @code{gnome-shell-assets} (default: ...)
13629 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13631 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13632 Configuration of the Xorg graphical server.
13634 @item @code{xsession} (default: @code{(xinitrc)})
13635 Script to run before starting a X session.
13637 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13638 File name of the @code{dbus-daemon} executable.
13640 @item @code{gdm} (default: @code{gdm})
13641 The GDM package to use.
13645 @defvr {Scheme Variable} slim-service-type
13646 This is the type for the SLiM graphical login manager for X11.
13648 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13649 allows users to choose a session from the log-in screen using @kbd{F1}. It
13650 also honors @file{~/.xsession} files.
13652 Unlike GDM, SLiM does not spawn the user session on a different VT after
13653 logging in, which means that you can only start one graphical session. If you
13654 want to be able to run multiple graphical sessions at the same time you have
13655 to add multiple SLiM services to your system services. The following example
13656 shows how to replace the default GDM service with two SLiM services on tty7
13660 (use-modules (gnu services)
13661 (gnu services desktop)
13662 (gnu services xorg)
13663 (srfi srfi-1)) ;for 'remove'
13667 (services (cons* (service slim-service-type (slim-configuration
13670 (service slim-service-type (slim-configuration
13673 (remove (lambda (service)
13674 (eq? (service-kind service) gdm-service-type))
13675 %desktop-services))))
13680 @deftp {Data Type} slim-configuration
13681 Data type representing the configuration of @code{slim-service-type}.
13684 @item @code{allow-empty-passwords?} (default: @code{#t})
13685 Whether to allow logins with empty passwords.
13687 @item @code{auto-login?} (default: @code{#f})
13688 @itemx @code{default-user} (default: @code{""})
13689 When @code{auto-login?} is false, SLiM presents a log-in screen.
13691 When @code{auto-login?} is true, SLiM logs in directly as
13692 @code{default-user}.
13694 @item @code{theme} (default: @code{%default-slim-theme})
13695 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13696 The graphical theme to use and its name.
13698 @item @code{auto-login-session} (default: @code{#f})
13699 If true, this must be the name of the executable to start as the default
13700 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13702 If false, a session described by one of the available @file{.desktop}
13703 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13707 You must install at least one window manager in the system profile or in
13708 your user profile. Failing to do that, if @code{auto-login-session} is
13709 false, you will be unable to log in.
13712 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13713 Configuration of the Xorg graphical server.
13715 @item @code{display} (default @code{":0"})
13716 The display on which to start the Xorg graphical server.
13718 @item @code{vt} (default @code{"vt7"})
13719 The VT on which to start the Xorg graphical server.
13721 @item @code{xauth} (default: @code{xauth})
13722 The XAuth package to use.
13724 @item @code{shepherd} (default: @code{shepherd})
13725 The Shepherd package used when invoking @command{halt} and
13728 @item @code{sessreg} (default: @code{sessreg})
13729 The sessreg package used in order to register the session.
13731 @item @code{slim} (default: @code{slim})
13732 The SLiM package to use.
13736 @defvr {Scheme Variable} %default-theme
13737 @defvrx {Scheme Variable} %default-theme-name
13738 The default SLiM theme and its name.
13742 @deftp {Data Type} sddm-configuration
13743 This is the data type representing the sddm service configuration.
13746 @item @code{display-server} (default: "x11")
13747 Select display server to use for the greeter. Valid values are "x11"
13750 @item @code{numlock} (default: "on")
13751 Valid values are "on", "off" or "none".
13753 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13754 Command to run when halting.
13756 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13757 Command to run when rebooting.
13759 @item @code{theme} (default "maldives")
13760 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13762 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13763 Directory to look for themes.
13765 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13766 Directory to look for faces.
13768 @item @code{default-path} (default "/run/current-system/profile/bin")
13769 Default PATH to use.
13771 @item @code{minimum-uid} (default: 1000)
13772 Minimum UID displayed in SDDM and allowed for log-in.
13774 @item @code{maximum-uid} (default: 2000)
13775 Maximum UID to display in SDDM.
13777 @item @code{remember-last-user?} (default #t)
13778 Remember last user.
13780 @item @code{remember-last-session?} (default #t)
13781 Remember last session.
13783 @item @code{hide-users} (default "")
13784 Usernames to hide from SDDM greeter.
13786 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13787 Users with shells listed will be hidden from the SDDM greeter.
13789 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13790 Script to run before starting a wayland session.
13792 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13793 Directory to look for desktop files starting wayland sessions.
13795 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13796 Configuration of the Xorg graphical server.
13798 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13801 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13804 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13805 Script to run after starting xorg-server.
13807 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13808 Script to run before stopping xorg-server.
13810 @item @code{xsession-command} (default: @code{xinitrc})
13811 Script to run before starting a X session.
13813 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13814 Directory to look for desktop files starting X sessions.
13816 @item @code{minimum-vt} (default: 7)
13819 @item @code{auto-login-user} (default "")
13820 User to use for auto-login.
13822 @item @code{auto-login-session} (default "")
13823 Desktop file to use for auto-login.
13825 @item @code{relogin?} (default #f)
13826 Relogin after logout.
13831 @cindex login manager
13833 @deffn {Scheme Procedure} sddm-service config
13834 Return a service that spawns the SDDM graphical login manager for config of
13835 type @code{<sddm-configuration>}.
13838 (sddm-service (sddm-configuration
13839 (auto-login-user "Alice")
13840 (auto-login-session "xfce.desktop")))
13844 @cindex Xorg, configuration
13845 @deftp {Data Type} xorg-configuration
13846 This data type represents the configuration of the Xorg graphical display
13847 server. Note that there is not Xorg service; instead, the X server is started
13848 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13849 of these display managers aggregates an @code{xorg-configuration} record.
13852 @item @code{modules} (default: @code{%default-xorg-modules})
13853 This is a list of @dfn{module packages} loaded by the Xorg
13854 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13856 @item @code{fonts} (default: @code{%default-xorg-fonts})
13857 This is a list of font directories to add to the server's @dfn{font path}.
13859 @item @code{drivers} (default: @code{'()})
13860 This must be either the empty list, in which case Xorg chooses a graphics
13861 driver automatically, or a list of driver names that will be tried in this
13862 order---e.g., @code{("modesetting" "vesa")}.
13864 @item @code{resolutions} (default: @code{'()})
13865 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13866 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13869 @cindex keyboard layout, for Xorg
13870 @cindex keymap, for Xorg
13871 @item @code{keyboard-layout} (default: @code{#f})
13872 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13873 English (``qwerty'') for a 105-key PC keyboard.
13875 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13876 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13877 information on how to specify the keyboard layout.
13879 @item @code{extra-config} (default: @code{'()})
13880 This is a list of strings or objects appended to the configuration file. It
13881 is used to pass extra text to be added verbatim to the configuration file.
13883 @item @code{server} (default: @code{xorg-server})
13884 This is the package providing the Xorg server.
13886 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13887 This is the list of command-line arguments to pass to the X server. The
13888 default is @code{-nolisten tcp}.
13892 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13893 [@var{login-manager-service-type}]
13894 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13895 @var{config}, an @code{<xorg-configuration>} record.
13897 Since the Xorg configuration is embedded in the log-in manager's
13898 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13899 shorthand to set the Xorg configuration.
13902 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13903 Return a @code{startx} script in which the modules, fonts, etc. specified
13904 in @var{config}, are available. The result should be used in place of
13907 Usually the X server is started by a login manager.
13911 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13912 Add @var{package}, a package for a screen locker or screen saver whose
13913 command is @var{program}, to the set of setuid programs and add a PAM entry
13914 for it. For example:
13917 (screen-locker-service xlockmore "xlock")
13920 makes the good ol' XlockMore usable.
13924 @node Printing Services
13925 @subsection Printing Services
13927 @cindex printer support with CUPS
13928 The @code{(gnu services cups)} module provides a Guix service definition
13929 for the CUPS printing service. To add printer support to a Guix
13930 system, add a @code{cups-service} to the operating system definition:
13932 @deffn {Scheme Variable} cups-service-type
13933 The service type for the CUPS print server. Its value should be a valid
13934 CUPS configuration (see below). To use the default settings, simply
13937 (service cups-service-type)
13941 The CUPS configuration controls the basic things about your CUPS
13942 installation: what interfaces it listens on, what to do if a print job
13943 fails, how much logging to do, and so on. To actually add a printer,
13944 you have to visit the @url{http://localhost:631} URL, or use a tool such
13945 as GNOME's printer configuration services. By default, configuring a
13946 CUPS service will generate a self-signed certificate if needed, for
13947 secure connections to the print server.
13949 Suppose you want to enable the Web interface of CUPS and also add
13950 support for Epson printers @i{via} the @code{escpr} package and for HP
13951 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13952 like this (you need to use the @code{(gnu packages cups)} module):
13955 (service cups-service-type
13956 (cups-configuration
13957 (web-interface? #t)
13959 (list cups-filters escpr hplip-minimal))))
13962 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13963 package then it is suggested that you install the @code{hplip} package,
13964 either in your OS configuration file or as your user.
13966 The available configuration parameters follow. Each parameter
13967 definition is preceded by its type; for example, @samp{string-list foo}
13968 indicates that the @code{foo} parameter should be specified as a list of
13969 strings. There is also a way to specify the configuration as a string,
13970 if you have an old @code{cupsd.conf} file that you want to port over
13971 from some other system; see the end for more details.
13973 @c The following documentation was initially generated by
13974 @c (generate-documentation) in (gnu services cups). Manually maintained
13975 @c documentation is better, so we shouldn't hesitate to edit below as
13976 @c needed. However if the change you want to make to this documentation
13977 @c can be done in an automated way, it's probably easier to change
13978 @c (generate-documentation) than to make it below and have to deal with
13979 @c the churn as CUPS updates.
13982 Available @code{cups-configuration} fields are:
13984 @deftypevr {@code{cups-configuration} parameter} package cups
13988 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13989 Drivers and other extensions to the CUPS package.
13992 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13993 Configuration of where to write logs, what directories to use for print
13994 spools, and related privileged configuration parameters.
13996 Available @code{files-configuration} fields are:
13998 @deftypevr {@code{files-configuration} parameter} log-location access-log
13999 Defines the access log filename. Specifying a blank filename disables
14000 access log generation. The value @code{stderr} causes log entries to be
14001 sent to the standard error file when the scheduler is running in the
14002 foreground, or to the system log daemon when run in the background. The
14003 value @code{syslog} causes log entries to be sent to the system log
14004 daemon. The server name may be included in filenames using the string
14005 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14007 Defaults to @samp{"/var/log/cups/access_log"}.
14010 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14011 Where CUPS should cache data.
14013 Defaults to @samp{"/var/cache/cups"}.
14016 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14017 Specifies the permissions for all configuration files that the scheduler
14020 Note that the permissions for the printers.conf file are currently
14021 masked to only allow access from the scheduler user (typically root).
14022 This is done because printer device URIs sometimes contain sensitive
14023 authentication information that should not be generally known on the
14024 system. There is no way to disable this security feature.
14026 Defaults to @samp{"0640"}.
14029 @deftypevr {@code{files-configuration} parameter} log-location error-log
14030 Defines the error log filename. Specifying a blank filename disables
14031 error log generation. The value @code{stderr} causes log entries to be
14032 sent to the standard error file when the scheduler is running in the
14033 foreground, or to the system log daemon when run in the background. The
14034 value @code{syslog} causes log entries to be sent to the system log
14035 daemon. The server name may be included in filenames using the string
14036 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14038 Defaults to @samp{"/var/log/cups/error_log"}.
14041 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14042 Specifies which errors are fatal, causing the scheduler to exit. The
14047 No errors are fatal.
14050 All of the errors below are fatal.
14053 Browsing initialization errors are fatal, for example failed connections
14054 to the DNS-SD daemon.
14057 Configuration file syntax errors are fatal.
14060 Listen or Port errors are fatal, except for IPv6 failures on the
14061 loopback or @code{any} addresses.
14064 Log file creation or write errors are fatal.
14067 Bad startup file permissions are fatal, for example shared TLS
14068 certificate and key files with world-read permissions.
14071 Defaults to @samp{"all -browse"}.
14074 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14075 Specifies whether the file pseudo-device can be used for new printer
14076 queues. The URI @uref{file:///dev/null} is always allowed.
14078 Defaults to @samp{#f}.
14081 @deftypevr {@code{files-configuration} parameter} string group
14082 Specifies the group name or ID that will be used when executing external
14085 Defaults to @samp{"lp"}.
14088 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14089 Specifies the permissions for all log files that the scheduler writes.
14091 Defaults to @samp{"0644"}.
14094 @deftypevr {@code{files-configuration} parameter} log-location page-log
14095 Defines the page log filename. Specifying a blank filename disables
14096 page log generation. The value @code{stderr} causes log entries to be
14097 sent to the standard error file when the scheduler is running in the
14098 foreground, or to the system log daemon when run in the background. The
14099 value @code{syslog} causes log entries to be sent to the system log
14100 daemon. The server name may be included in filenames using the string
14101 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14103 Defaults to @samp{"/var/log/cups/page_log"}.
14106 @deftypevr {@code{files-configuration} parameter} string remote-root
14107 Specifies the username that is associated with unauthenticated accesses
14108 by clients claiming to be the root user. The default is @code{remroot}.
14110 Defaults to @samp{"remroot"}.
14113 @deftypevr {@code{files-configuration} parameter} file-name request-root
14114 Specifies the directory that contains print jobs and other HTTP request
14117 Defaults to @samp{"/var/spool/cups"}.
14120 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14121 Specifies the level of security sandboxing that is applied to print
14122 filters, backends, and other child processes of the scheduler; either
14123 @code{relaxed} or @code{strict}. This directive is currently only
14124 used/supported on macOS.
14126 Defaults to @samp{strict}.
14129 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14130 Specifies the location of TLS certificates and private keys. CUPS will
14131 look for public and private keys in this directory: a @code{.crt} files
14132 for PEM-encoded certificates and corresponding @code{.key} files for
14133 PEM-encoded private keys.
14135 Defaults to @samp{"/etc/cups/ssl"}.
14138 @deftypevr {@code{files-configuration} parameter} file-name server-root
14139 Specifies the directory containing the server configuration files.
14141 Defaults to @samp{"/etc/cups"}.
14144 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14145 Specifies whether the scheduler calls fsync(2) after writing
14146 configuration or state files.
14148 Defaults to @samp{#f}.
14151 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14152 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14155 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14156 Specifies the directory where temporary files are stored.
14158 Defaults to @samp{"/var/spool/cups/tmp"}.
14161 @deftypevr {@code{files-configuration} parameter} string user
14162 Specifies the user name or ID that is used when running external
14165 Defaults to @samp{"lp"}.
14169 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14170 Specifies the logging level for the AccessLog file. The @code{config}
14171 level logs when printers and classes are added, deleted, or modified and
14172 when configuration files are accessed or updated. The @code{actions}
14173 level logs when print jobs are submitted, held, released, modified, or
14174 canceled, and any of the conditions for @code{config}. The @code{all}
14175 level logs all requests.
14177 Defaults to @samp{actions}.
14180 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14181 Specifies whether to purge job history data automatically when it is no
14182 longer required for quotas.
14184 Defaults to @samp{#f}.
14187 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14188 Specifies which protocols to use for local printer sharing.
14190 Defaults to @samp{dnssd}.
14193 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14194 Specifies whether the CUPS web interface is advertised.
14196 Defaults to @samp{#f}.
14199 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14200 Specifies whether shared printers are advertised.
14202 Defaults to @samp{#f}.
14205 @deftypevr {@code{cups-configuration} parameter} string classification
14206 Specifies the security classification of the server. Any valid banner
14207 name can be used, including "classified", "confidential", "secret",
14208 "topsecret", and "unclassified", or the banner can be omitted to disable
14209 secure printing functions.
14211 Defaults to @samp{""}.
14214 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14215 Specifies whether users may override the classification (cover page) of
14216 individual print jobs using the @code{job-sheets} option.
14218 Defaults to @samp{#f}.
14221 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14222 Specifies the default type of authentication to use.
14224 Defaults to @samp{Basic}.
14227 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14228 Specifies whether encryption will be used for authenticated requests.
14230 Defaults to @samp{Required}.
14233 @deftypevr {@code{cups-configuration} parameter} string default-language
14234 Specifies the default language to use for text and web content.
14236 Defaults to @samp{"en"}.
14239 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14240 Specifies the default paper size for new print queues. @samp{"Auto"}
14241 uses a locale-specific default, while @samp{"None"} specifies there is
14242 no default paper size. Specific size names are typically
14243 @samp{"Letter"} or @samp{"A4"}.
14245 Defaults to @samp{"Auto"}.
14248 @deftypevr {@code{cups-configuration} parameter} string default-policy
14249 Specifies the default access policy to use.
14251 Defaults to @samp{"default"}.
14254 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14255 Specifies whether local printers are shared by default.
14257 Defaults to @samp{#t}.
14260 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14261 Specifies the delay for updating of configuration and state files, in
14262 seconds. A value of 0 causes the update to happen as soon as possible,
14263 typically within a few milliseconds.
14265 Defaults to @samp{30}.
14268 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14269 Specifies what to do when an error occurs. Possible values are
14270 @code{abort-job}, which will discard the failed print job;
14271 @code{retry-job}, which will retry the job at a later time;
14272 @code{retry-this-job}, which retries the failed job immediately; and
14273 @code{stop-printer}, which stops the printer.
14275 Defaults to @samp{stop-printer}.
14278 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14279 Specifies the maximum cost of filters that are run concurrently, which
14280 can be used to minimize disk, memory, and CPU resource problems. A
14281 limit of 0 disables filter limiting. An average print to a
14282 non-PostScript printer needs a filter limit of about 200. A PostScript
14283 printer needs about half that (100). Setting the limit below these
14284 thresholds will effectively limit the scheduler to printing a single job
14287 Defaults to @samp{0}.
14290 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14291 Specifies the scheduling priority of filters that are run to print a
14292 job. The nice value ranges from 0, the highest priority, to 19, the
14295 Defaults to @samp{0}.
14298 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14299 Specifies whether to do reverse lookups on connecting clients. The
14300 @code{double} setting causes @code{cupsd} to verify that the hostname
14301 resolved from the address matches one of the addresses returned for that
14302 hostname. Double lookups also prevent clients with unregistered
14303 addresses from connecting to your server. Only set this option to
14304 @code{#t} or @code{double} if absolutely required.
14306 Defaults to @samp{#f}.
14309 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14310 Specifies the number of seconds to wait before killing the filters and
14311 backend associated with a canceled or held job.
14313 Defaults to @samp{30}.
14316 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14317 Specifies the interval between retries of jobs in seconds. This is
14318 typically used for fax queues but can also be used with normal print
14319 queues whose error policy is @code{retry-job} or
14320 @code{retry-current-job}.
14322 Defaults to @samp{30}.
14325 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14326 Specifies the number of retries that are done for jobs. This is
14327 typically used for fax queues but can also be used with normal print
14328 queues whose error policy is @code{retry-job} or
14329 @code{retry-current-job}.
14331 Defaults to @samp{5}.
14334 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14335 Specifies whether to support HTTP keep-alive connections.
14337 Defaults to @samp{#t}.
14340 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14341 Specifies how long an idle client connection remains open, in seconds.
14343 Defaults to @samp{30}.
14346 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14347 Specifies the maximum size of print files, IPP requests, and HTML form
14348 data. A limit of 0 disables the limit check.
14350 Defaults to @samp{0}.
14353 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14354 Listens on the specified interfaces for connections. Valid values are
14355 of the form @var{address}:@var{port}, where @var{address} is either an
14356 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14357 indicate all addresses. Values can also be file names of local UNIX
14358 domain sockets. The Listen directive is similar to the Port directive
14359 but allows you to restrict access to specific interfaces or networks.
14362 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14363 Specifies the number of pending connections that will be allowed. This
14364 normally only affects very busy servers that have reached the MaxClients
14365 limit, but can also be triggered by large numbers of simultaneous
14366 connections. When the limit is reached, the operating system will
14367 refuse additional connections until the scheduler can accept the pending
14370 Defaults to @samp{128}.
14373 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14374 Specifies a set of additional access controls.
14376 Available @code{location-access-controls} fields are:
14378 @deftypevr {@code{location-access-controls} parameter} file-name path
14379 Specifies the URI path to which the access control applies.
14382 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14383 Access controls for all access to this path, in the same format as the
14384 @code{access-controls} of @code{operation-access-control}.
14386 Defaults to @samp{()}.
14389 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14390 Access controls for method-specific access to this path.
14392 Defaults to @samp{()}.
14394 Available @code{method-access-controls} fields are:
14396 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14397 If @code{#t}, apply access controls to all methods except the listed
14398 methods. Otherwise apply to only the listed methods.
14400 Defaults to @samp{#f}.
14403 @deftypevr {@code{method-access-controls} parameter} method-list methods
14404 Methods to which this access control applies.
14406 Defaults to @samp{()}.
14409 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14410 Access control directives, as a list of strings. Each string should be
14411 one directive, such as "Order allow,deny".
14413 Defaults to @samp{()}.
14418 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14419 Specifies the number of debugging messages that are retained for logging
14420 if an error occurs in a print job. Debug messages are logged regardless
14421 of the LogLevel setting.
14423 Defaults to @samp{100}.
14426 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14427 Specifies the level of logging for the ErrorLog file. The value
14428 @code{none} stops all logging while @code{debug2} logs everything.
14430 Defaults to @samp{info}.
14433 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14434 Specifies the format of the date and time in the log files. The value
14435 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14437 Defaults to @samp{standard}.
14440 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14441 Specifies the maximum number of simultaneous clients that are allowed by
14444 Defaults to @samp{100}.
14447 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14448 Specifies the maximum number of simultaneous clients that are allowed
14449 from a single address.
14451 Defaults to @samp{100}.
14454 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14455 Specifies the maximum number of copies that a user can print of each
14458 Defaults to @samp{9999}.
14461 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14462 Specifies the maximum time a job may remain in the @code{indefinite}
14463 hold state before it is canceled. A value of 0 disables cancellation of
14466 Defaults to @samp{0}.
14469 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14470 Specifies the maximum number of simultaneous jobs that are allowed. Set
14471 to 0 to allow an unlimited number of jobs.
14473 Defaults to @samp{500}.
14476 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14477 Specifies the maximum number of simultaneous jobs that are allowed per
14478 printer. A value of 0 allows up to MaxJobs jobs per printer.
14480 Defaults to @samp{0}.
14483 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14484 Specifies the maximum number of simultaneous jobs that are allowed per
14485 user. A value of 0 allows up to MaxJobs jobs per user.
14487 Defaults to @samp{0}.
14490 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14491 Specifies the maximum time a job may take to print before it is
14492 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14494 Defaults to @samp{10800}.
14497 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14498 Specifies the maximum size of the log files before they are rotated, in
14499 bytes. The value 0 disables log rotation.
14501 Defaults to @samp{1048576}.
14504 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14505 Specifies the maximum amount of time to allow between files in a
14506 multiple file print job, in seconds.
14508 Defaults to @samp{300}.
14511 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14512 Specifies the format of PageLog lines. Sequences beginning with percent
14513 (@samp{%}) characters are replaced with the corresponding information,
14514 while all other characters are copied literally. The following percent
14515 sequences are recognized:
14519 insert a single percent character
14522 insert the value of the specified IPP attribute
14525 insert the number of copies for the current page
14528 insert the current page number
14531 insert the current date and time in common log format
14537 insert the printer name
14540 insert the username
14543 A value of the empty string disables page logging. The string @code{%p
14544 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14545 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14548 Defaults to @samp{""}.
14551 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14552 Passes the specified environment variable(s) to child processes; a list
14555 Defaults to @samp{()}.
14558 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14559 Specifies named access control policies.
14561 Available @code{policy-configuration} fields are:
14563 @deftypevr {@code{policy-configuration} parameter} string name
14564 Name of the policy.
14567 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14568 Specifies an access list for a job's private values. @code{@@ACL} maps
14569 to the printer's requesting-user-name-allowed or
14570 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14571 owner. @code{@@SYSTEM} maps to the groups listed for the
14572 @code{system-group} field of the @code{files-config} configuration,
14573 which is reified into the @code{cups-files.conf(5)} file. Other
14574 possible elements of the access list include specific user names, and
14575 @code{@@@var{group}} to indicate members of a specific group. The
14576 access list may also be simply @code{all} or @code{default}.
14578 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14581 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14582 Specifies the list of job values to make private, or @code{all},
14583 @code{default}, or @code{none}.
14585 Defaults to @samp{"job-name job-originating-host-name
14586 job-originating-user-name phone"}.
14589 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14590 Specifies an access list for a subscription's private values.
14591 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14592 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14593 owner. @code{@@SYSTEM} maps to the groups listed for the
14594 @code{system-group} field of the @code{files-config} configuration,
14595 which is reified into the @code{cups-files.conf(5)} file. Other
14596 possible elements of the access list include specific user names, and
14597 @code{@@@var{group}} to indicate members of a specific group. The
14598 access list may also be simply @code{all} or @code{default}.
14600 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14603 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14604 Specifies the list of job values to make private, or @code{all},
14605 @code{default}, or @code{none}.
14607 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14608 notify-subscriber-user-name notify-user-data"}.
14611 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14612 Access control by IPP operation.
14614 Defaults to @samp{()}.
14618 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14619 Specifies whether job files (documents) are preserved after a job is
14620 printed. If a numeric value is specified, job files are preserved for
14621 the indicated number of seconds after printing. Otherwise a boolean
14622 value applies indefinitely.
14624 Defaults to @samp{86400}.
14627 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14628 Specifies whether the job history is preserved after a job is printed.
14629 If a numeric value is specified, the job history is preserved for the
14630 indicated number of seconds after printing. If @code{#t}, the job
14631 history is preserved until the MaxJobs limit is reached.
14633 Defaults to @samp{#t}.
14636 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14637 Specifies the amount of time to wait for job completion before
14638 restarting the scheduler.
14640 Defaults to @samp{30}.
14643 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14644 Specifies the maximum amount of memory to use when converting documents
14645 into bitmaps for a printer.
14647 Defaults to @samp{"128m"}.
14650 @deftypevr {@code{cups-configuration} parameter} string server-admin
14651 Specifies the email address of the server administrator.
14653 Defaults to @samp{"root@@localhost.localdomain"}.
14656 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14657 The ServerAlias directive is used for HTTP Host header validation when
14658 clients connect to the scheduler from external interfaces. Using the
14659 special name @code{*} can expose your system to known browser-based DNS
14660 rebinding attacks, even when accessing sites through a firewall. If the
14661 auto-discovery of alternate names does not work, we recommend listing
14662 each alternate name with a ServerAlias directive instead of using
14665 Defaults to @samp{*}.
14668 @deftypevr {@code{cups-configuration} parameter} string server-name
14669 Specifies the fully-qualified host name of the server.
14671 Defaults to @samp{"localhost"}.
14674 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14675 Specifies what information is included in the Server header of HTTP
14676 responses. @code{None} disables the Server header. @code{ProductOnly}
14677 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14678 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14679 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14680 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14681 2.0.0 (@var{uname}) IPP/2.0}.
14683 Defaults to @samp{Minimal}.
14686 @deftypevr {@code{cups-configuration} parameter} string set-env
14687 Set the specified environment variable to be passed to child processes.
14689 Defaults to @samp{"variable value"}.
14692 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14693 Listens on the specified interfaces for encrypted connections. Valid
14694 values are of the form @var{address}:@var{port}, where @var{address} is
14695 either an IPv6 address enclosed in brackets, an IPv4 address, or
14696 @code{*} to indicate all addresses.
14698 Defaults to @samp{()}.
14701 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14702 Sets encryption options. By default, CUPS only supports encryption
14703 using TLS v1.0 or higher using known secure cipher suites. The
14704 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14705 required for some older clients that do not implement newer ones. The
14706 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14707 older clients that do not support TLS v1.0.
14709 Defaults to @samp{()}.
14712 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14713 Specifies whether the scheduler requires clients to strictly adhere to
14714 the IPP specifications.
14716 Defaults to @samp{#f}.
14719 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14720 Specifies the HTTP request timeout, in seconds.
14722 Defaults to @samp{300}.
14726 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14727 Specifies whether the web interface is enabled.
14729 Defaults to @samp{#f}.
14732 At this point you're probably thinking ``oh dear, Guix manual, I like
14733 you but you can stop already with the configuration options''. Indeed.
14734 However, one more point: it could be that you have an existing
14735 @code{cupsd.conf} that you want to use. In that case, you can pass an
14736 @code{opaque-cups-configuration} as the configuration of a
14737 @code{cups-service-type}.
14739 Available @code{opaque-cups-configuration} fields are:
14741 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14745 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14746 The contents of the @code{cupsd.conf}, as a string.
14749 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14750 The contents of the @code{cups-files.conf} file, as a string.
14753 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14754 strings of the same name, you could instantiate a CUPS service like
14758 (service cups-service-type
14759 (opaque-cups-configuration
14760 (cupsd.conf cupsd.conf)
14761 (cups-files.conf cups-files.conf)))
14765 @node Desktop Services
14766 @subsection Desktop Services
14768 The @code{(gnu services desktop)} module provides services that are
14769 usually useful in the context of a ``desktop'' setup---that is, on a
14770 machine running a graphical display server, possibly with graphical user
14771 interfaces, etc. It also defines services that provide specific desktop
14772 environments like GNOME, Xfce or MATE.
14774 To simplify things, the module defines a variable containing the set of
14775 services that users typically expect on a machine with a graphical
14776 environment and networking:
14778 @defvr {Scheme Variable} %desktop-services
14779 This is a list of services that builds upon @code{%base-services} and
14780 adds or adjusts services for a typical ``desktop'' setup.
14782 In particular, it adds a graphical login manager (@pxref{X Window,
14783 @code{gdm-service-type}}), screen lockers, a network management tool
14784 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
14785 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
14786 energy and color management services, the @code{elogind} login and seat
14787 manager, the Polkit privilege service, the GeoClue location service, the
14788 AccountsService daemon that allows authorized users change system passwords,
14789 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
14790 name service switch service configured to be able to use @code{nss-mdns}
14791 (@pxref{Name Service Switch, mDNS}).
14794 The @code{%desktop-services} variable can be used as the @code{services}
14795 field of an @code{operating-system} declaration (@pxref{operating-system
14796 Reference, @code{services}}).
14798 Additionally, the @code{gnome-desktop-service-type},
14799 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14800 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14801 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14802 services like the backlight adjustment helpers and the power management
14803 utilities are added to the system, extending @code{polkit} and @code{dbus}
14804 appropriately, allowing GNOME to operate with elevated privileges on a
14805 limited number of special-purpose system interfaces. Additionally,
14806 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14807 metapackage to the system profile. Likewise, adding the Xfce service
14808 not only adds the @code{xfce} metapackage to the system profile, but it
14809 also gives the Thunar file manager the ability to open a ``root-mode''
14810 file management window, if the user authenticates using the
14811 administrator's password via the standard polkit graphical interface.
14812 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14813 appropriately, allowing MATE to operate with elevated privileges on a
14814 limited number of special-purpose system interfaces. Additionally,
14815 adding a service of type @code{mate-desktop-service-type} adds the MATE
14816 metapackage to the system profile. ``Adding Enlightenment'' means that
14817 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14818 are set as setuid, allowing Enlightenment's screen locker and other
14819 functionality to work as expetected.
14821 The desktop environments in Guix use the Xorg display server by
14822 default. If you'd like to use the newer display server protocol
14823 called Wayland, you need to use the @code{sddm-service} instead of
14824 GDM as the graphical login manager. You should then
14825 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14826 also try starting GNOME on Wayland manually from a TTY with the
14827 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14828 gnome-session``. Currently only GNOME has support for Wayland.
14830 @defvr {Scheme Variable} gnome-desktop-service-type
14831 This is the type of the service that adds the @uref{https://www.gnome.org,
14832 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14833 object (see below.)
14835 This service adds the @code{gnome} package to the system profile, and extends
14836 polkit with the actions from @code{gnome-settings-daemon}.
14839 @deftp {Data Type} gnome-desktop-configuration
14840 Configuration record for the GNOME desktop environment.
14843 @item @code{gnome} (default: @code{gnome})
14844 The GNOME package to use.
14848 @defvr {Scheme Variable} xfce-desktop-service-type
14849 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14850 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14853 This service adds the @code{xfce} package to the system profile, and
14854 extends polkit with the ability for @code{thunar} to manipulate the file
14855 system as root from within a user session, after the user has authenticated
14856 with the administrator's password.
14859 @deftp {Data Type} xfce-desktop-configuration
14860 Configuration record for the Xfce desktop environment.
14863 @item @code{xfce} (default: @code{xfce})
14864 The Xfce package to use.
14868 @deffn {Scheme Variable} mate-desktop-service-type
14869 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14870 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14871 object (see below.)
14873 This service adds the @code{mate} package to the system
14874 profile, and extends polkit with the actions from
14875 @code{mate-settings-daemon}.
14878 @deftp {Data Type} mate-desktop-configuration
14879 Configuration record for the MATE desktop environment.
14882 @item @code{mate} (default: @code{mate})
14883 The MATE package to use.
14887 @deffn {Scheme Variable} enlightenment-desktop-service-type
14888 Return a service that adds the @code{enlightenment} package to the system
14889 profile, and extends dbus with actions from @code{efl}.
14892 @deftp {Data Type} enlightenment-desktop-service-configuration
14894 @item @code{enlightenment} (default: @code{enlightenment})
14895 The enlightenment package to use.
14899 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14900 the default @code{%desktop-services} variable doesn't include any of
14901 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14902 @code{%desktop-services} in the @code{services} field of your
14903 @code{operating-system}:
14906 (use-modules (gnu))
14907 (use-service-modules desktop)
14910 ;; cons* adds items to the list given as its last argument.
14911 (services (cons* (service gnome-desktop-service-type)
14912 (service xfce-desktop-service)
14913 %desktop-services))
14917 These desktop environments will then be available as options in the
14918 graphical login window.
14920 The actual service definitions included in @code{%desktop-services} and
14921 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14922 are described below.
14924 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14925 Return a service that runs the ``system bus'', using @var{dbus}, with
14926 support for @var{services}.
14928 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14929 facility. Its system bus is used to allow system services to communicate
14930 and to be notified of system-wide events.
14932 @var{services} must be a list of packages that provide an
14933 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14934 and policy files. For example, to allow avahi-daemon to use the system bus,
14935 @var{services} must be equal to @code{(list avahi)}.
14938 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14939 Return a service that runs the @code{elogind} login and
14940 seat management daemon. @uref{https://github.com/elogind/elogind,
14941 Elogind} exposes a D-Bus interface that can be used to know which users
14942 are logged in, know what kind of sessions they have open, suspend the
14943 system, inhibit system suspend, reboot the system, and other tasks.
14945 Elogind handles most system-level power events for a computer, for
14946 example suspending the system when a lid is closed, or shutting it down
14947 when the power button is pressed.
14949 The @var{config} keyword argument specifies the configuration for
14950 elogind, and should be the result of an @code{(elogind-configuration
14951 (@var{parameter} @var{value})...)} invocation. Available parameters and
14952 their default values are:
14955 @item kill-user-processes?
14957 @item kill-only-users
14959 @item kill-exclude-users
14961 @item inhibit-delay-max-seconds
14963 @item handle-power-key
14965 @item handle-suspend-key
14967 @item handle-hibernate-key
14969 @item handle-lid-switch
14971 @item handle-lid-switch-docked
14973 @item power-key-ignore-inhibited?
14975 @item suspend-key-ignore-inhibited?
14977 @item hibernate-key-ignore-inhibited?
14979 @item lid-switch-ignore-inhibited?
14981 @item holdoff-timeout-seconds
14985 @item idle-action-seconds
14987 @item runtime-directory-size-percent
14989 @item runtime-directory-size
14993 @item suspend-state
14994 @code{("mem" "standby" "freeze")}
14997 @item hibernate-state
14999 @item hibernate-mode
15000 @code{("platform" "shutdown")}
15001 @item hybrid-sleep-state
15003 @item hybrid-sleep-mode
15004 @code{("suspend" "platform" "shutdown")}
15008 @deffn {Scheme Procedure} accountsservice-service @
15009 [#:accountsservice @var{accountsservice}]
15010 Return a service that runs AccountsService, a system service that can
15011 list available accounts, change their passwords, and so on.
15012 AccountsService integrates with PolicyKit to enable unprivileged users
15013 to acquire the capability to modify their system configuration.
15014 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15015 accountsservice web site} for more information.
15017 The @var{accountsservice} keyword argument is the @code{accountsservice}
15018 package to expose as a service.
15021 @deffn {Scheme Procedure} polkit-service @
15022 [#:polkit @var{polkit}]
15023 Return a service that runs the
15024 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15025 management service}, which allows system administrators to grant access to
15026 privileged operations in a structured way. By querying the Polkit service, a
15027 privileged system component can know when it should grant additional
15028 capabilities to ordinary users. For example, an ordinary user can be granted
15029 the capability to suspend the system if the user is logged in locally.
15032 @defvr {Scheme Variable} upower-service-type
15033 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15034 system-wide monitor for power consumption and battery levels, with the given
15035 configuration settings.
15037 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15038 notably used by GNOME.
15041 @deftp {Data Type} upower-configuration
15042 Data type representation the configuration for UPower.
15046 @item @code{upower} (default: @var{upower})
15047 Package to use for @code{upower}.
15049 @item @code{watts-up-pro?} (default: @code{#f})
15050 Enable the Watts Up Pro device.
15052 @item @code{poll-batteries?} (default: @code{#t})
15053 Enable polling the kernel for battery level changes.
15055 @item @code{ignore-lid?} (default: @code{#f})
15056 Ignore the lid state, this can be useful if it's incorrect on a device.
15058 @item @code{use-percentage-for-policy?} (default: @code{#f})
15059 Whether battery percentage based policy should be used. The default is to use
15060 the time left, change to @code{#t} to use the percentage.
15062 @item @code{percentage-low} (default: @code{10})
15063 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15064 at which the battery is considered low.
15066 @item @code{percentage-critical} (default: @code{3})
15067 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15068 at which the battery is considered critical.
15070 @item @code{percentage-action} (default: @code{2})
15071 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15072 at which action will be taken.
15074 @item @code{time-low} (default: @code{1200})
15075 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15076 seconds at which the battery is considered low.
15078 @item @code{time-critical} (default: @code{300})
15079 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15080 seconds at which the battery is considered critical.
15082 @item @code{time-action} (default: @code{120})
15083 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15084 seconds at which action will be taken.
15086 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15087 The action taken when @code{percentage-action} or @code{time-action} is
15088 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15090 Possible values are:
15100 @code{'hybrid-sleep}.
15106 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15107 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15108 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15109 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15110 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15113 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
15114 Return a service that runs @command{colord}, a system service with a D-Bus
15115 interface to manage the color profiles of input and output devices such as
15116 screens and scanners. It is notably used by the GNOME Color Manager graphical
15117 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15118 site} for more information.
15121 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15122 Return a configuration allowing an application to access GeoClue
15123 location data. @var{name} is the Desktop ID of the application, without
15124 the @code{.desktop} part. If @var{allowed?} is true, the application
15125 will have access to location information by default. The boolean
15126 @var{system?} value indicates whether an application is a system component
15127 or not. Finally @var{users} is a list of UIDs of all users for which
15128 this application is allowed location info access. An empty users list
15129 means that all users are allowed.
15132 @defvr {Scheme Variable} %standard-geoclue-applications
15133 The standard list of well-known GeoClue application configurations,
15134 granting authority to the GNOME date-and-time utility to ask for the
15135 current location in order to set the time zone, and allowing the
15136 IceCat and Epiphany web browsers to request location information.
15137 IceCat and Epiphany both query the user before allowing a web page to
15138 know the user's location.
15141 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15142 [#:whitelist '()] @
15143 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15144 [#:submit-data? #f]
15145 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15146 [#:submission-nick "geoclue"] @
15147 [#:applications %standard-geoclue-applications]
15148 Return a service that runs the GeoClue location service. This service
15149 provides a D-Bus interface to allow applications to request access to a
15150 user's physical location, and optionally to add information to online
15151 location databases. See
15152 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15153 web site} for more information.
15156 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15157 [@w{#:auto-enable? #f}]
15158 Return a service that runs the @command{bluetoothd} daemon, which
15159 manages all the Bluetooth devices and provides a number of D-Bus
15160 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15161 powered automatically at boot, which can be useful when using a
15162 bluetooth keyboard or mouse.
15164 Users need to be in the @code{lp} group to access the D-Bus service.
15167 @node Sound Services
15168 @subsection Sound Services
15170 @cindex sound support
15172 @cindex PulseAudio, sound support
15174 The @code{(gnu services sound)} module provides a service to configure the
15175 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15176 preferred ALSA output driver.
15178 @deffn {Scheme Variable} alsa-service-type
15179 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15180 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15181 configuration file. The value for this type is a @command{alsa-configuration}
15182 record as in this example:
15185 (service alsa-service-type)
15188 See below for details about @code{alsa-configuration}.
15191 @deftp {Data Type} alsa-configuration
15192 Data type representing the configuration for @code{alsa-service}.
15195 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15196 @code{alsa-plugins} package to use.
15198 @item @code{pulseaudio?} (default: @var{#t})
15199 Whether ALSA applications should transparently be made to use the
15200 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15202 Using PulseAudio allows you to run several sound-producing applications
15203 at the same time and to individual control them @i{via}
15204 @command{pavucontrol}, among other things.
15206 @item @code{extra-options} (default: @var{""})
15207 String to append to the @file{/etc/asound.conf} file.
15212 Individual users who want to override the system configuration of ALSA can do
15213 it with the @file{~/.asoundrc} file:
15216 # In guix, we have to specify the absolute path for plugins.
15218 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15221 # Routing ALSA to jack:
15222 # <http://jackaudio.org/faq/routing_alsa.html>.
15226 0 system:playback_1
15227 1 system:playback_2
15244 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15248 @node Database Services
15249 @subsection Database Services
15253 The @code{(gnu services databases)} module provides the following services.
15255 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15256 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15257 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15258 Return a service that runs @var{postgresql}, the PostgreSQL database
15261 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15262 creates a database cluster with @var{locale} as the default
15263 locale, stored in @var{data-directory}. It then listens on @var{port}.
15265 @cindex postgresql extension-packages
15266 Additional extensions are loaded from packages listed in
15267 @var{extension-packages}. Extensions are available at runtime. For instance,
15268 to create a geographic database using the @code{postgis} extension, a user can
15269 configure the postgresql-service as in this example:
15273 (use-package-modules databases geo)
15277 ;; postgresql is required to run `psql' but postgis is not required for
15278 ;; proper operation.
15279 (packages (cons* postgresql %base-packages))
15282 (postgresql-service #:extension-packages (list postgis))
15286 Then the extension becomes visible and you can initialise an empty geographic
15287 database in this way:
15291 > create database postgistest;
15292 > \connect postgistest;
15293 > create extension postgis;
15294 > create extension postgis_topology;
15297 There is no need to add this field for contrib extensions such as hstore or
15298 dblink as they are already loadable by postgresql. This field is only
15299 required to add extensions provided by other packages.
15302 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15303 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15306 The optional @var{config} argument specifies the configuration for
15307 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15310 @deftp {Data Type} mysql-configuration
15311 Data type representing the configuration of @var{mysql-service}.
15314 @item @code{mysql} (default: @var{mariadb})
15315 Package object of the MySQL database server, can be either @var{mariadb}
15318 For MySQL, a temporary root password will be displayed at activation time.
15319 For MariaDB, the root password is empty.
15321 @item @code{port} (default: @code{3306})
15322 TCP port on which the database server listens for incoming connections.
15326 @defvr {Scheme Variable} memcached-service-type
15327 This is the service type for the @uref{https://memcached.org/,
15328 Memcached} service, which provides a distributed in memory cache. The
15329 value for the service type is a @code{memcached-configuration} object.
15333 (service memcached-service-type)
15336 @deftp {Data Type} memcached-configuration
15337 Data type representing the configuration of memcached.
15340 @item @code{memcached} (default: @code{memcached})
15341 The Memcached package to use.
15343 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15344 Network interfaces on which to listen.
15346 @item @code{tcp-port} (default: @code{11211})
15347 Port on which to accept connections on,
15349 @item @code{udp-port} (default: @code{11211})
15350 Port on which to accept UDP connections on, a value of 0 will disable
15351 listening on a UDP socket.
15353 @item @code{additional-options} (default: @code{'()})
15354 Additional command line options to pass to @code{memcached}.
15358 @defvr {Scheme Variable} mongodb-service-type
15359 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15360 The value for the service type is a @code{mongodb-configuration} object.
15364 (service mongodb-service-type)
15367 @deftp {Data Type} mongodb-configuration
15368 Data type representing the configuration of mongodb.
15371 @item @code{mongodb} (default: @code{mongodb})
15372 The MongoDB package to use.
15374 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15375 The configuration file for MongoDB.
15377 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15378 This value is used to create the directory, so that it exists and is
15379 owned by the mongodb user. It should match the data-directory which
15380 MongoDB is configured to use through the configuration file.
15384 @defvr {Scheme Variable} redis-service-type
15385 This is the service type for the @uref{https://redis.io/, Redis}
15386 key/value store, whose value is a @code{redis-configuration} object.
15389 @deftp {Data Type} redis-configuration
15390 Data type representing the configuration of redis.
15393 @item @code{redis} (default: @code{redis})
15394 The Redis package to use.
15396 @item @code{bind} (default: @code{"127.0.0.1"})
15397 Network interface on which to listen.
15399 @item @code{port} (default: @code{6379})
15400 Port on which to accept connections on, a value of 0 will disable
15401 listening on a TCP socket.
15403 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15404 Directory in which to store the database and related files.
15408 @node Mail Services
15409 @subsection Mail Services
15413 The @code{(gnu services mail)} module provides Guix service definitions
15414 for email services: IMAP, POP3, and LMTP servers, as well as mail
15415 transport agents (MTAs). Lots of acronyms! These services are detailed
15416 in the subsections below.
15418 @subsubheading Dovecot Service
15420 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15421 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15424 By default, Dovecot does not need much configuration; the default
15425 configuration object created by @code{(dovecot-configuration)} will
15426 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15427 certificate will be generated for TLS-protected connections, though
15428 Dovecot will also listen on cleartext ports by default. There are a
15429 number of options, though, which mail administrators might need to change,
15430 and as is the case with other services, Guix allows the system
15431 administrator to specify these parameters via a uniform Scheme interface.
15433 For example, to specify that mail is located at @code{maildir~/.mail},
15434 one would instantiate the Dovecot service like this:
15437 (dovecot-service #:config
15438 (dovecot-configuration
15439 (mail-location "maildir:~/.mail")))
15442 The available configuration parameters follow. Each parameter
15443 definition is preceded by its type; for example, @samp{string-list foo}
15444 indicates that the @code{foo} parameter should be specified as a list of
15445 strings. There is also a way to specify the configuration as a string,
15446 if you have an old @code{dovecot.conf} file that you want to port over
15447 from some other system; see the end for more details.
15449 @c The following documentation was initially generated by
15450 @c (generate-documentation) in (gnu services mail). Manually maintained
15451 @c documentation is better, so we shouldn't hesitate to edit below as
15452 @c needed. However if the change you want to make to this documentation
15453 @c can be done in an automated way, it's probably easier to change
15454 @c (generate-documentation) than to make it below and have to deal with
15455 @c the churn as dovecot updates.
15457 Available @code{dovecot-configuration} fields are:
15459 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15460 The dovecot package.
15463 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15464 A list of IPs or hosts where to listen for connections. @samp{*}
15465 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15466 interfaces. If you want to specify non-default ports or anything more
15467 complex, customize the address and port fields of the
15468 @samp{inet-listener} of the specific services you are interested in.
15471 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15472 List of protocols we want to serve. Available protocols include
15473 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15475 Available @code{protocol-configuration} fields are:
15477 @deftypevr {@code{protocol-configuration} parameter} string name
15478 The name of the protocol.
15481 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15482 UNIX socket path to the master authentication server to find users.
15483 This is used by imap (for shared users) and lda.
15484 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15487 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15488 Space separated list of plugins to load.
15491 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15492 Maximum number of IMAP connections allowed for a user from each IP
15493 address. NOTE: The username is compared case-sensitively.
15494 Defaults to @samp{10}.
15499 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15500 List of services to enable. Available services include @samp{imap},
15501 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15504 Available @code{service-configuration} fields are:
15506 @deftypevr {@code{service-configuration} parameter} string kind
15507 The service kind. Valid values include @code{director},
15508 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15509 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15510 @code{tcpwrap}, @code{quota-warning}, or anything else.
15513 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15514 Listeners for the service. A listener is either a
15515 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15516 an @code{inet-listener-configuration}.
15517 Defaults to @samp{()}.
15519 Available @code{unix-listener-configuration} fields are:
15521 @deftypevr {@code{unix-listener-configuration} parameter} string path
15522 Path to the file, relative to @code{base-dir} field. This is also used as
15526 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15527 The access mode for the socket.
15528 Defaults to @samp{"0600"}.
15531 @deftypevr {@code{unix-listener-configuration} parameter} string user
15532 The user to own the socket.
15533 Defaults to @samp{""}.
15536 @deftypevr {@code{unix-listener-configuration} parameter} string group
15537 The group to own the socket.
15538 Defaults to @samp{""}.
15542 Available @code{fifo-listener-configuration} fields are:
15544 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15545 Path to the file, relative to @code{base-dir} field. This is also used as
15549 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15550 The access mode for the socket.
15551 Defaults to @samp{"0600"}.
15554 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15555 The user to own the socket.
15556 Defaults to @samp{""}.
15559 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15560 The group to own the socket.
15561 Defaults to @samp{""}.
15565 Available @code{inet-listener-configuration} fields are:
15567 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15568 The protocol to listen for.
15571 @deftypevr {@code{inet-listener-configuration} parameter} string address
15572 The address on which to listen, or empty for all addresses.
15573 Defaults to @samp{""}.
15576 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15577 The port on which to listen.
15580 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15581 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15583 Defaults to @samp{#t}.
15588 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15589 Maximum number of simultaneous client connections per process. Once
15590 this number of connections is received, the next incoming connection
15591 will prompt Dovecot to spawn another process. If set to 0,
15592 @code{default-client-limit} is used instead.
15594 Defaults to @samp{0}.
15598 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15599 Number of connections to handle before starting a new process.
15600 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15601 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15602 Defaults to @samp{1}.
15606 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15607 Maximum number of processes that can exist for this service. If set to
15608 0, @code{default-process-limit} is used instead.
15610 Defaults to @samp{0}.
15614 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15615 Number of processes to always keep waiting for more connections.
15616 Defaults to @samp{0}.
15619 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15620 If you set @samp{service-count 0}, you probably need to grow
15622 Defaults to @samp{256000000}.
15627 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15628 Dict configuration, as created by the @code{dict-configuration}
15631 Available @code{dict-configuration} fields are:
15633 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15634 A list of key-value pairs that this dict should hold.
15635 Defaults to @samp{()}.
15640 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15641 A list of passdb configurations, each one created by the
15642 @code{passdb-configuration} constructor.
15644 Available @code{passdb-configuration} fields are:
15646 @deftypevr {@code{passdb-configuration} parameter} string driver
15647 The driver that the passdb should use. Valid values include
15648 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15650 Defaults to @samp{"pam"}.
15653 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15654 Space separated list of arguments to the passdb driver.
15655 Defaults to @samp{""}.
15660 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15661 List of userdb configurations, each one created by the
15662 @code{userdb-configuration} constructor.
15664 Available @code{userdb-configuration} fields are:
15666 @deftypevr {@code{userdb-configuration} parameter} string driver
15667 The driver that the userdb should use. Valid values include
15668 @samp{passwd} and @samp{static}.
15669 Defaults to @samp{"passwd"}.
15672 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15673 Space separated list of arguments to the userdb driver.
15674 Defaults to @samp{""}.
15677 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15678 Override fields from passwd.
15679 Defaults to @samp{()}.
15684 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15685 Plug-in configuration, created by the @code{plugin-configuration}
15689 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15690 List of namespaces. Each item in the list is created by the
15691 @code{namespace-configuration} constructor.
15693 Available @code{namespace-configuration} fields are:
15695 @deftypevr {@code{namespace-configuration} parameter} string name
15696 Name for this namespace.
15699 @deftypevr {@code{namespace-configuration} parameter} string type
15700 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15701 Defaults to @samp{"private"}.
15704 @deftypevr {@code{namespace-configuration} parameter} string separator
15705 Hierarchy separator to use. You should use the same separator for
15706 all namespaces or some clients get confused. @samp{/} is usually a good
15707 one. The default however depends on the underlying mail storage
15709 Defaults to @samp{""}.
15712 @deftypevr {@code{namespace-configuration} parameter} string prefix
15713 Prefix required to access this namespace. This needs to be
15714 different for all namespaces. For example @samp{Public/}.
15715 Defaults to @samp{""}.
15718 @deftypevr {@code{namespace-configuration} parameter} string location
15719 Physical location of the mailbox. This is in the same format as
15720 mail_location, which is also the default for it.
15721 Defaults to @samp{""}.
15724 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15725 There can be only one INBOX, and this setting defines which
15727 Defaults to @samp{#f}.
15730 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15731 If namespace is hidden, it's not advertised to clients via NAMESPACE
15732 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15733 useful when converting from another server with different namespaces
15734 which you want to deprecate but still keep working. For example you can
15735 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15737 Defaults to @samp{#f}.
15740 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15741 Show the mailboxes under this namespace with the LIST command. This
15742 makes the namespace visible for clients that do not support the NAMESPACE
15743 extension. The special @code{children} value lists child mailboxes, but
15744 hides the namespace prefix.
15745 Defaults to @samp{#t}.
15748 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15749 Namespace handles its own subscriptions. If set to @code{#f}, the
15750 parent namespace handles them. The empty prefix should always have this
15752 Defaults to @samp{#t}.
15755 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15756 List of predefined mailboxes in this namespace.
15757 Defaults to @samp{()}.
15759 Available @code{mailbox-configuration} fields are:
15761 @deftypevr {@code{mailbox-configuration} parameter} string name
15762 Name for this mailbox.
15765 @deftypevr {@code{mailbox-configuration} parameter} string auto
15766 @samp{create} will automatically create this mailbox.
15767 @samp{subscribe} will both create and subscribe to the mailbox.
15768 Defaults to @samp{"no"}.
15771 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15772 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15773 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15774 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15775 Defaults to @samp{()}.
15782 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15783 Base directory where to store runtime data.
15784 Defaults to @samp{"/var/run/dovecot/"}.
15787 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15788 Greeting message for clients.
15789 Defaults to @samp{"Dovecot ready."}.
15792 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15793 List of trusted network ranges. Connections from these IPs are
15794 allowed to override their IP addresses and ports (for logging and for
15795 authentication checks). @samp{disable-plaintext-auth} is also ignored
15796 for these networks. Typically you would specify your IMAP proxy servers
15798 Defaults to @samp{()}.
15801 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15802 List of login access check sockets (e.g.@: tcpwrap).
15803 Defaults to @samp{()}.
15806 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15807 Show more verbose process titles (in ps). Currently shows user name
15808 and IP address. Useful for seeing who is actually using the IMAP
15809 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15811 Defaults to @samp{#f}.
15814 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15815 Should all processes be killed when Dovecot master process shuts down.
15816 Setting this to @code{#f} means that Dovecot can be upgraded without
15817 forcing existing client connections to close (although that could also
15818 be a problem if the upgrade is e.g.@: due to a security fix).
15819 Defaults to @samp{#t}.
15822 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15823 If non-zero, run mail commands via this many connections to doveadm
15824 server, instead of running them directly in the same process.
15825 Defaults to @samp{0}.
15828 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15829 UNIX socket or host:port used for connecting to doveadm server.
15830 Defaults to @samp{"doveadm-server"}.
15833 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15834 List of environment variables that are preserved on Dovecot startup
15835 and passed down to all of its child processes. You can also give
15836 key=value pairs to always set specific settings.
15839 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15840 Disable LOGIN command and all other plaintext authentications unless
15841 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15842 matches the local IP (i.e.@: you're connecting from the same computer),
15843 the connection is considered secure and plaintext authentication is
15844 allowed. See also ssl=required setting.
15845 Defaults to @samp{#t}.
15848 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15849 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15850 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15851 for caching to be used.
15852 Defaults to @samp{0}.
15855 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15856 Time to live for cached data. After TTL expires the cached record
15857 is no longer used, *except* if the main database lookup returns internal
15858 failure. We also try to handle password changes automatically: If
15859 user's previous authentication was successful, but this one wasn't, the
15860 cache isn't used. For now this works only with plaintext
15862 Defaults to @samp{"1 hour"}.
15865 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15866 TTL for negative hits (user not found, password mismatch).
15867 0 disables caching them completely.
15868 Defaults to @samp{"1 hour"}.
15871 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15872 List of realms for SASL authentication mechanisms that need them.
15873 You can leave it empty if you don't want to support multiple realms.
15874 Many clients simply use the first one listed here, so keep the default
15876 Defaults to @samp{()}.
15879 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15880 Default realm/domain to use if none was specified. This is used for
15881 both SASL realms and appending @@domain to username in plaintext
15883 Defaults to @samp{""}.
15886 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15887 List of allowed characters in username. If the user-given username
15888 contains a character not listed in here, the login automatically fails.
15889 This is just an extra check to make sure user can't exploit any
15890 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15891 you want to allow all characters, set this value to empty.
15892 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15895 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15896 Username character translations before it's looked up from
15897 databases. The value contains series of from -> to characters. For
15898 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15899 translated to @samp{@@}.
15900 Defaults to @samp{""}.
15903 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15904 Username formatting before it's looked up from databases. You can
15905 use the standard variables here, e.g.@: %Lu would lowercase the username,
15906 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15907 change the @samp{@@} into @samp{-AT-}. This translation is done after
15908 @samp{auth-username-translation} changes.
15909 Defaults to @samp{"%Lu"}.
15912 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15913 If you want to allow master users to log in by specifying the master
15914 username within the normal username string (i.e.@: not using SASL
15915 mechanism's support for it), you can specify the separator character
15916 here. The format is then <username><separator><master username>.
15917 UW-IMAP uses @samp{*} as the separator, so that could be a good
15919 Defaults to @samp{""}.
15922 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15923 Username to use for users logging in with ANONYMOUS SASL
15925 Defaults to @samp{"anonymous"}.
15928 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15929 Maximum number of dovecot-auth worker processes. They're used to
15930 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15931 They're automatically created and destroyed as needed.
15932 Defaults to @samp{30}.
15935 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15936 Host name to use in GSSAPI principal names. The default is to use
15937 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15938 allow all keytab entries.
15939 Defaults to @samp{""}.
15942 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15943 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15944 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15945 need to change the auth service to run as root to be able to read this
15947 Defaults to @samp{""}.
15950 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15951 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15952 and @samp{ntlm-auth} helper.
15953 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15954 Defaults to @samp{#f}.
15957 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15958 Path for Samba's @samp{ntlm-auth} helper binary.
15959 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15962 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15963 Time to delay before replying to failed authentications.
15964 Defaults to @samp{"2 secs"}.
15967 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15968 Require a valid SSL client certificate or the authentication
15970 Defaults to @samp{#f}.
15973 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15974 Take the username from client's SSL certificate, using
15975 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15977 Defaults to @samp{#f}.
15980 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15981 List of wanted authentication mechanisms. Supported mechanisms are:
15982 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15983 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15984 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15985 @samp{disable-plaintext-auth} setting.
15988 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15989 List of IPs or hostnames to all director servers, including ourself.
15990 Ports can be specified as ip:port. The default port is the same as what
15991 director service's @samp{inet-listener} is using.
15992 Defaults to @samp{()}.
15995 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15996 List of IPs or hostnames to all backend mail servers. Ranges are
15997 allowed too, like 10.0.0.10-10.0.0.30.
15998 Defaults to @samp{()}.
16001 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16002 How long to redirect users to a specific server after it no longer
16003 has any connections.
16004 Defaults to @samp{"15 min"}.
16007 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16008 How the username is translated before being hashed. Useful values
16009 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16010 are shared within domain.
16011 Defaults to @samp{"%Lu"}.
16014 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16015 Log file to use for error messages. @samp{syslog} logs to syslog,
16016 @samp{/dev/stderr} logs to stderr.
16017 Defaults to @samp{"syslog"}.
16020 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16021 Log file to use for informational messages. Defaults to
16023 Defaults to @samp{""}.
16026 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16027 Log file to use for debug messages. Defaults to
16028 @samp{info-log-path}.
16029 Defaults to @samp{""}.
16032 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16033 Syslog facility to use if you're logging to syslog. Usually if you
16034 don't want to use @samp{mail}, you'll use local0..local7. Also other
16035 standard facilities are supported.
16036 Defaults to @samp{"mail"}.
16039 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16040 Log unsuccessful authentication attempts and the reasons why they
16042 Defaults to @samp{#f}.
16045 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16046 In case of password mismatches, log the attempted password. Valid
16047 values are no, plain and sha1. sha1 can be useful for detecting brute
16048 force password attempts vs. user simply trying the same password over
16049 and over again. You can also truncate the value to n chars by appending
16050 ":n" (e.g.@: sha1:6).
16051 Defaults to @samp{"no"}.
16054 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16055 Even more verbose logging for debugging purposes. Shows for example
16057 Defaults to @samp{#f}.
16060 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16061 In case of password mismatches, log the passwords and used scheme so
16062 the problem can be debugged. Enabling this also enables
16064 Defaults to @samp{#f}.
16067 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16068 Enable mail process debugging. This can help you figure out why
16069 Dovecot isn't finding your mails.
16070 Defaults to @samp{#f}.
16073 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16074 Show protocol level SSL errors.
16075 Defaults to @samp{#f}.
16078 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16079 Prefix for each line written to log file. % codes are in
16080 strftime(3) format.
16081 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16084 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16085 List of elements we want to log. The elements which have a
16086 non-empty variable value are joined together to form a comma-separated
16090 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16091 Login log format. %s contains @samp{login-log-format-elements}
16092 string, %$ contains the data we want to log.
16093 Defaults to @samp{"%$: %s"}.
16096 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16097 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16098 of possible variables you can use.
16099 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16102 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16103 Format to use for logging mail deliveries. You can use variables:
16106 Delivery status message (e.g.@: @samp{saved to INBOX})
16118 Defaults to @samp{"msgid=%m: %$"}.
16121 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16122 Location for users' mailboxes. The default is empty, which means
16123 that Dovecot tries to find the mailboxes automatically. This won't work
16124 if the user doesn't yet have any mail, so you should explicitly tell
16125 Dovecot the full location.
16127 If you're using mbox, giving a path to the INBOX
16128 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16129 where the other mailboxes are kept. This is called the "root mail
16130 directory", and it must be the first path given in the
16131 @samp{mail-location} setting.
16133 There are a few special variables you can use, eg.:
16139 user part in user@@domain, same as %u if there's no domain
16141 domain part in user@@domain, empty if there's no domain
16146 See doc/wiki/Variables.txt for full list. Some examples:
16148 @item maildir:~/Maildir
16149 @item mbox:~/mail:INBOX=/var/mail/%u
16150 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16152 Defaults to @samp{""}.
16155 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16156 System user and group used to access mails. If you use multiple,
16157 userdb can override these by returning uid or gid fields. You can use
16158 either numbers or names. <doc/wiki/UserIds.txt>.
16159 Defaults to @samp{""}.
16162 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16164 Defaults to @samp{""}.
16167 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16168 Group to enable temporarily for privileged operations. Currently
16169 this is used only with INBOX when either its initial creation or
16170 dotlocking fails. Typically this is set to "mail" to give access to
16172 Defaults to @samp{""}.
16175 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16176 Grant access to these supplementary groups for mail processes.
16177 Typically these are used to set up access to shared mailboxes. Note
16178 that it may be dangerous to set these if users can create
16179 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16180 could allow a user to delete others' mailboxes, or ln -s
16181 /secret/shared/box ~/mail/mybox would allow reading it).
16182 Defaults to @samp{""}.
16185 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16186 Allow full file system access to clients. There's no access checks
16187 other than what the operating system does for the active UID/GID. It
16188 works with both maildir and mboxes, allowing you to prefix mailboxes
16189 names with e.g.@: /path/ or ~user/.
16190 Defaults to @samp{#f}.
16193 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16194 Don't use mmap() at all. This is required if you store indexes to
16195 shared file systems (NFS or clustered file system).
16196 Defaults to @samp{#f}.
16199 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16200 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16201 supports @samp{O_EXCL} since version 3, so this should be safe to use
16202 nowadays by default.
16203 Defaults to @samp{#t}.
16206 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16207 When to use fsync() or fdatasync() calls:
16210 Whenever necessary to avoid losing important data
16212 Useful with e.g.@: NFS when write()s are delayed
16214 Never use it (best performance, but crashes can lose data).
16216 Defaults to @samp{"optimized"}.
16219 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16220 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16221 NFS caches whenever needed. If you're using only a single mail server
16223 Defaults to @samp{#f}.
16226 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16227 Mail index files also exist in NFS. Setting this to yes requires
16228 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16229 Defaults to @samp{#f}.
16232 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16233 Locking method for index files. Alternatives are fcntl, flock and
16234 dotlock. Dotlocking uses some tricks which may create more disk I/O
16235 than other locking methods. NFS users: flock doesn't work, remember to
16236 change @samp{mmap-disable}.
16237 Defaults to @samp{"fcntl"}.
16240 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16241 Directory in which LDA/LMTP temporarily stores incoming mails >128
16243 Defaults to @samp{"/tmp"}.
16246 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16247 Valid UID range for users. This is mostly to make sure that users can't
16248 log in as daemons or other system users. Note that denying root logins is
16249 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16251 Defaults to @samp{500}.
16254 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16256 Defaults to @samp{0}.
16259 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16260 Valid GID range for users. Users having non-valid GID as primary group ID
16261 aren't allowed to log in. If user belongs to supplementary groups with
16262 non-valid GIDs, those groups are not set.
16263 Defaults to @samp{1}.
16266 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16268 Defaults to @samp{0}.
16271 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16272 Maximum allowed length for mail keyword name. It's only forced when
16273 trying to create new keywords.
16274 Defaults to @samp{50}.
16277 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16278 List of directories under which chrooting is allowed for mail
16279 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16280 too). This setting doesn't affect @samp{login-chroot}
16281 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16282 "/./" in home dirs are ignored. WARNING: Never add directories here
16283 which local users can modify, that may lead to root exploit. Usually
16284 this should be done only if you don't allow shell access for users.
16285 <doc/wiki/Chrooting.txt>.
16286 Defaults to @samp{()}.
16289 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16290 Default chroot directory for mail processes. This can be overridden
16291 for specific users in user database by giving /./ in user's home
16292 directory (e.g.@: /home/./user chroots into /home). Note that usually
16293 there is no real need to do chrooting, Dovecot doesn't allow users to
16294 access files outside their mail directory anyway. If your home
16295 directories are prefixed with the chroot directory, append "/."@: to
16296 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16297 Defaults to @samp{""}.
16300 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16301 UNIX socket path to master authentication server to find users.
16302 This is used by imap (for shared users) and lda.
16303 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16306 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16307 Directory where to look up mail plugins.
16308 Defaults to @samp{"/usr/lib/dovecot"}.
16311 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16312 List of plugins to load for all services. Plugins specific to IMAP,
16313 LDA, etc.@: are added to this list in their own .conf files.
16314 Defaults to @samp{()}.
16317 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16318 The minimum number of mails in a mailbox before updates are done to
16319 cache file. This allows optimizing Dovecot's behavior to do less disk
16320 writes at the cost of more disk reads.
16321 Defaults to @samp{0}.
16324 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16325 When IDLE command is running, mailbox is checked once in a while to
16326 see if there are any new mails or other changes. This setting defines
16327 the minimum time to wait between those checks. Dovecot can also use
16328 dnotify, inotify and kqueue to find out immediately when changes
16330 Defaults to @samp{"30 secs"}.
16333 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16334 Save mails with CR+LF instead of plain LF. This makes sending those
16335 mails take less CPU, especially with sendfile() syscall with Linux and
16336 FreeBSD. But it also creates a bit more disk I/O which may just make it
16337 slower. Also note that if other software reads the mboxes/maildirs,
16338 they may handle the extra CRs wrong and cause problems.
16339 Defaults to @samp{#f}.
16342 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16343 By default LIST command returns all entries in maildir beginning
16344 with a dot. Enabling this option makes Dovecot return only entries
16345 which are directories. This is done by stat()ing each entry, so it
16346 causes more disk I/O.
16347 (For systems setting struct @samp{dirent->d_type} this check is free
16348 and it's done always regardless of this setting).
16349 Defaults to @samp{#f}.
16352 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16353 When copying a message, do it with hard links whenever possible.
16354 This makes the performance much better, and it's unlikely to have any
16356 Defaults to @samp{#t}.
16359 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16360 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16361 directory only when its mtime changes unexpectedly or when we can't find
16362 the mail otherwise.
16363 Defaults to @samp{#f}.
16366 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16367 Which locking methods to use for locking mbox. There are four
16372 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16373 solution. If you want to use /var/mail/ like directory, the users will
16374 need write access to that directory.
16376 Same as dotlock, but if it fails because of permissions or because there
16377 isn't enough disk space, just skip it.
16379 Use this if possible. Works with NFS too if lockd is used.
16381 May not exist in all systems. Doesn't work with NFS.
16383 May not exist in all systems. Doesn't work with NFS.
16386 You can use multiple locking methods; if you do the order they're declared
16387 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16388 locking methods as well. Some operating systems don't allow using some of
16389 them simultaneously.
16392 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16396 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16397 Maximum time to wait for lock (all of them) before aborting.
16398 Defaults to @samp{"5 mins"}.
16401 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16402 If dotlock exists but the mailbox isn't modified in any way,
16403 override the lock file after this much time.
16404 Defaults to @samp{"2 mins"}.
16407 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16408 When mbox changes unexpectedly we have to fully read it to find out
16409 what changed. If the mbox is large this can take a long time. Since
16410 the change is usually just a newly appended mail, it'd be faster to
16411 simply read the new mails. If this setting is enabled, Dovecot does
16412 this but still safely fallbacks to re-reading the whole mbox file
16413 whenever something in mbox isn't how it's expected to be. The only real
16414 downside to this setting is that if some other MUA changes message
16415 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16416 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16417 Defaults to @samp{#t}.
16420 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16421 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16422 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16423 @samp{mbox-dirty-syncs} is ignored.
16424 Defaults to @samp{#f}.
16427 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16428 Delay writing mbox headers until doing a full write sync (EXPUNGE
16429 and CHECK commands and when closing the mailbox). This is especially
16430 useful for POP3 where clients often delete all mails. The downside is
16431 that our changes aren't immediately visible to other MUAs.
16432 Defaults to @samp{#t}.
16435 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16436 If mbox size is smaller than this (e.g.@: 100k), don't write index
16437 files. If an index file already exists it's still read, just not
16439 Defaults to @samp{0}.
16442 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16443 Maximum dbox file size until it's rotated.
16444 Defaults to @samp{10000000}.
16447 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16448 Maximum dbox file age until it's rotated. Typically in days. Day
16449 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16451 Defaults to @samp{"1d"}.
16454 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16455 When creating new mdbox files, immediately preallocate their size to
16456 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16457 with some file systems (ext4, xfs).
16458 Defaults to @samp{#f}.
16461 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16462 sdbox and mdbox support saving mail attachments to external files,
16463 which also allows single instance storage for them. Other backends
16464 don't support this for now.
16466 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16468 Directory root where to store mail attachments. Disabled, if empty.
16469 Defaults to @samp{""}.
16472 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16473 Attachments smaller than this aren't saved externally. It's also
16474 possible to write a plugin to disable saving specific attachments
16476 Defaults to @samp{128000}.
16479 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16480 File system backend to use for saving attachments:
16483 No SiS done by Dovecot (but this might help FS's own deduplication)
16485 SiS with immediate byte-by-byte comparison during saving
16486 @item sis-queue posix
16487 SiS with delayed comparison and deduplication.
16489 Defaults to @samp{"sis posix"}.
16492 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16493 Hash format to use in attachment filenames. You can add any text and
16494 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16495 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16496 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16497 Defaults to @samp{"%@{sha1@}"}.
16500 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16502 Defaults to @samp{100}.
16505 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16507 Defaults to @samp{1000}.
16510 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16511 Default VSZ (virtual memory size) limit for service processes.
16512 This is mainly intended to catch and kill processes that leak memory
16513 before they eat up everything.
16514 Defaults to @samp{256000000}.
16517 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16518 Login user is internally used by login processes. This is the most
16519 untrusted user in Dovecot system. It shouldn't have access to anything
16521 Defaults to @samp{"dovenull"}.
16524 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16525 Internal user is used by unprivileged processes. It should be
16526 separate from login user, so that login processes can't disturb other
16528 Defaults to @samp{"dovecot"}.
16531 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16532 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16533 Defaults to @samp{"required"}.
16536 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16537 PEM encoded X.509 SSL/TLS certificate (public key).
16538 Defaults to @samp{"</etc/dovecot/default.pem"}.
16541 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16542 PEM encoded SSL/TLS private key. The key is opened before
16543 dropping root privileges, so keep the key file unreadable by anyone but
16545 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16548 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16549 If key file is password protected, give the password here.
16550 Alternatively give it when starting dovecot with -p parameter. Since
16551 this file is often world-readable, you may want to place this setting
16552 instead to a different.
16553 Defaults to @samp{""}.
16556 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16557 PEM encoded trusted certificate authority. Set this only if you
16558 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16559 contain the CA certificate(s) followed by the matching
16560 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16561 Defaults to @samp{""}.
16564 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16565 Require that CRL check succeeds for client certificates.
16566 Defaults to @samp{#t}.
16569 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16570 Request client to send a certificate. If you also want to require
16571 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16572 Defaults to @samp{#f}.
16575 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16576 Which field from certificate to use for username. commonName and
16577 x500UniqueIdentifier are the usual choices. You'll also need to set
16578 @samp{auth-ssl-username-from-cert? #t}.
16579 Defaults to @samp{"commonName"}.
16582 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16583 Minimum SSL protocol version to accept.
16584 Defaults to @samp{"TLSv1"}.
16587 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16588 SSL ciphers to use.
16589 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16592 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16593 SSL crypto device to use, for valid values run "openssl engine".
16594 Defaults to @samp{""}.
16597 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16598 Address to use when sending rejection mails.
16599 %d expands to recipient domain.
16600 Defaults to @samp{"postmaster@@%d"}.
16603 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16604 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16605 and in LMTP replies. Default is the system's real hostname@@domain.
16606 Defaults to @samp{""}.
16609 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16610 If user is over quota, return with temporary failure instead of
16612 Defaults to @samp{#f}.
16615 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16616 Binary to use for sending mails.
16617 Defaults to @samp{"/usr/sbin/sendmail"}.
16620 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16621 If non-empty, send mails via this SMTP host[:port] instead of
16623 Defaults to @samp{""}.
16626 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16627 Subject: header to use for rejection mails. You can use the same
16628 variables as for @samp{rejection-reason} below.
16629 Defaults to @samp{"Rejected: %s"}.
16632 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16633 Human readable error message for rejection mails. You can use
16646 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16649 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16650 Delimiter character between local-part and detail in email
16652 Defaults to @samp{"+"}.
16655 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16656 Header where the original recipient address (SMTP's RCPT TO:
16657 address) is taken from if not available elsewhere. With dovecot-lda -a
16658 parameter overrides this. A commonly used header for this is
16660 Defaults to @samp{""}.
16663 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16664 Should saving a mail to a nonexistent mailbox automatically create
16666 Defaults to @samp{#f}.
16669 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16670 Should automatically created mailboxes be also automatically
16672 Defaults to @samp{#f}.
16675 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16676 Maximum IMAP command line length. Some clients generate very long
16677 command lines with huge mailboxes, so you may need to raise this if you
16678 get "Too long argument" or "IMAP command line too large" errors
16680 Defaults to @samp{64000}.
16683 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16684 IMAP logout format string:
16687 total number of bytes read from client
16689 total number of bytes sent to client.
16691 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16692 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@}"}.
16695 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16696 Override the IMAP CAPABILITY response. If the value begins with '+',
16697 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16698 Defaults to @samp{""}.
16701 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16702 How long to wait between "OK Still here" notifications when client
16704 Defaults to @samp{"2 mins"}.
16707 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16708 ID field names and values to send to clients. Using * as the value
16709 makes Dovecot use the default value. The following fields have default
16710 values currently: name, version, os, os-version, support-url,
16712 Defaults to @samp{""}.
16715 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16716 ID fields sent by client to log. * means everything.
16717 Defaults to @samp{""}.
16720 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16721 Workarounds for various client bugs:
16724 @item delay-newmail
16725 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16726 CHECK commands. Some clients ignore them otherwise, for example OSX
16727 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16728 may show user "Message no longer in server" errors. Note that OE6
16729 still breaks even with this workaround if synchronization is set to
16732 @item tb-extra-mailbox-sep
16733 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16734 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16735 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16737 @item tb-lsub-flags
16738 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16739 This makes Thunderbird realize they aren't selectable and show them
16740 greyed out, instead of only later giving "not selectable" popup error.
16742 Defaults to @samp{()}.
16745 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16746 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16747 Defaults to @samp{""}.
16751 Whew! Lots of configuration options. The nice thing about it though is
16752 that Guix has a complete interface to Dovecot's configuration
16753 language. This allows not only a nice way to declare configurations,
16754 but also offers reflective capabilities as well: users can write code to
16755 inspect and transform configurations from within Scheme.
16757 However, it could be that you just want to get a @code{dovecot.conf} up
16758 and running. In that case, you can pass an
16759 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16760 @code{dovecot-service}. As its name indicates, an opaque configuration
16761 does not have easy reflective capabilities.
16763 Available @code{opaque-dovecot-configuration} fields are:
16765 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16766 The dovecot package.
16769 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16770 The contents of the @code{dovecot.conf}, as a string.
16773 For example, if your @code{dovecot.conf} is just the empty string, you
16774 could instantiate a dovecot service like this:
16777 (dovecot-service #:config
16778 (opaque-dovecot-configuration
16782 @subsubheading OpenSMTPD Service
16784 @deffn {Scheme Variable} opensmtpd-service-type
16785 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16786 service, whose value should be an @code{opensmtpd-configuration} object
16787 as in this example:
16790 (service opensmtpd-service-type
16791 (opensmtpd-configuration
16792 (config-file (local-file "./my-smtpd.conf"))))
16796 @deftp {Data Type} opensmtpd-configuration
16797 Data type representing the configuration of opensmtpd.
16800 @item @code{package} (default: @var{opensmtpd})
16801 Package object of the OpenSMTPD SMTP server.
16803 @item @code{config-file} (default: @code{%default-opensmtpd-file})
16804 File-like object of the OpenSMTPD configuration file to use. By default
16805 it listens on the loopback network interface, and allows for mail from
16806 users and daemons on the local machine, as well as permitting email to
16807 remote servers. Run @command{man smtpd.conf} for more information.
16812 @subsubheading Exim Service
16814 @cindex mail transfer agent (MTA)
16815 @cindex MTA (mail transfer agent)
16818 @deffn {Scheme Variable} exim-service-type
16819 This is the type of the @uref{https://exim.org, Exim} mail transfer
16820 agent (MTA), whose value should be an @code{exim-configuration} object
16821 as in this example:
16824 (service exim-service-type
16825 (exim-configuration
16826 (config-file (local-file "./my-exim.conf"))))
16830 In order to use an @code{exim-service-type} service you must also have a
16831 @code{mail-aliases-service-type} service present in your
16832 @code{operating-system} (even if it has no aliases).
16834 @deftp {Data Type} exim-configuration
16835 Data type representing the configuration of exim.
16838 @item @code{package} (default: @var{exim})
16839 Package object of the Exim server.
16841 @item @code{config-file} (default: @code{#f})
16842 File-like object of the Exim configuration file to use. If its value is
16843 @code{#f} then use the default configuration file from the package
16844 provided in @code{package}. The resulting configuration file is loaded
16845 after setting the @code{exim_user} and @code{exim_group} configuration
16851 @subsubheading Getmail service
16856 @deffn {Scheme Variable} getmail-service-type
16857 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
16858 mail retriever, whose value should be an @code{getmail-configuration}.
16861 Available @code{getmail-configuration} fields are:
16863 @deftypevr {@code{getmail-configuration} parameter} symbol name
16864 A symbol to identify the getmail service.
16866 Defaults to @samp{"unset"}.
16870 @deftypevr {@code{getmail-configuration} parameter} package package
16871 The getmail package to use.
16875 @deftypevr {@code{getmail-configuration} parameter} string user
16876 The user to run getmail as.
16878 Defaults to @samp{"getmail"}.
16882 @deftypevr {@code{getmail-configuration} parameter} string group
16883 The group to run getmail as.
16885 Defaults to @samp{"getmail"}.
16889 @deftypevr {@code{getmail-configuration} parameter} string directory
16890 The getmail directory to use.
16892 Defaults to @samp{"/var/lib/getmail/default"}.
16896 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
16897 The getmail configuration file to use.
16899 Available @code{getmail-configuration-file} fields are:
16901 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
16902 What mail account to retrieve mail from, and how to access that account.
16904 Available @code{getmail-retriever-configuration} fields are:
16906 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
16907 The type of mail retriever to use. Valid values include @samp{passwd}
16910 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
16914 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
16915 Space separated list of arguments to the userdb driver.
16917 Defaults to @samp{unset}.
16921 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
16922 Space separated list of arguments to the userdb driver.
16924 Defaults to @samp{unset}.
16928 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
16929 Space separated list of arguments to the userdb driver.
16931 Defaults to @samp{#f}.
16935 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
16936 Override fields from passwd.
16938 Defaults to @samp{""}.
16942 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
16943 Override fields from passwd.
16945 Defaults to @samp{()}.
16949 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
16950 PEM-formatted key file to use for the TLS negotiation
16952 Defaults to @samp{""}.
16956 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
16957 PEM-formatted certificate file to use for the TLS negotiation
16959 Defaults to @samp{""}.
16963 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
16964 CA certificates to use
16966 Defaults to @samp{""}.
16970 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
16971 Extra retriever parameters
16973 Defaults to @samp{()}.
16979 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
16980 What to do with retrieved messages.
16982 Available @code{getmail-destination-configuration} fields are:
16984 @deftypevr {@code{getmail-destination-configuration} parameter} string type
16985 The type of mail destination. Valid values include @samp{Maildir},
16986 @samp{Mboxrd} and @samp{MDA_external}.
16988 Defaults to @samp{unset}.
16992 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
16993 The path option for the mail destination. The behaviour depends on the
16996 Defaults to @samp{""}.
17000 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17001 Extra destination parameters
17003 Defaults to @samp{()}.
17009 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17012 Available @code{getmail-options-configuration} fields are:
17014 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17015 If set to @samp{0}, getmail will only print warnings and errors. A
17016 value of @samp{1} means that messages will be printed about retrieving
17017 and deleting messages. If set to @samp{2}, getmail will print messages
17018 about each of it's actions.
17020 Defaults to @samp{1}.
17024 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17025 If true, getmail will retrieve all available messages. Otherwise it
17026 will only retrieve messages it hasn't seen previously.
17028 Defaults to @samp{#t}.
17032 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17033 If set to true, messages will be deleted from the server after
17034 retrieving and successfully delivering them. Otherwise, messages will
17035 be left on the server.
17037 Defaults to @samp{#f}.
17041 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17042 Getmail will delete messages this number of days after seeing them, if
17043 they have not been delivered. This means messages will be left on the
17044 server this number of days after delivering them. A value of @samp{0}
17045 disabled this feature.
17047 Defaults to @samp{0}.
17051 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17052 Delete messages larger than this of bytes after retrieving them, even if
17053 the delete and delete-after options are disabled. A value of @samp{0}
17054 disables this feature.
17056 Defaults to @samp{0}.
17060 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17061 Retrieve messages totalling up to this number of bytes before closing
17062 the session with the server. A value of @samp{0} disables this feature.
17064 Defaults to @samp{0}.
17068 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17069 Don't retrieve messages larger than this number of bytes. A value of
17070 @samp{0} disables this feature.
17072 Defaults to @samp{0}.
17076 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17077 If true, getmail will add a Delivered-To header to messages.
17079 Defaults to @samp{#t}.
17083 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17084 If set, getmail adds a Received header to the messages.
17086 Defaults to @samp{#t}.
17090 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17091 Getmail will record a log of its actions to the named file. A value of
17092 @samp{""} disables this feature.
17094 Defaults to @samp{""}.
17098 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17099 If true, getmail will record a log of its actions using the system
17102 Defaults to @samp{#t}.
17106 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17107 If true, getmail will log information about messages not retrieved and
17108 the reason for not retrieving them, as well as starting and ending
17111 Defaults to @samp{#t}.
17115 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17116 Extra options to include.
17118 Defaults to @samp{()}.
17126 @deftypevr {@code{getmail-configuration} parameter} list idle
17127 A list of mailboxes that getmail should wait on the server for new mail
17128 notifications. This depends on the server supporting the IDLE
17131 Defaults to @samp{()}.
17135 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17136 Environment variables to set for getmail.
17138 Defaults to @samp{()}.
17142 @subsubheading Mail Aliases Service
17144 @cindex email aliases
17145 @cindex aliases, for email addresses
17147 @deffn {Scheme Variable} mail-aliases-service-type
17148 This is the type of the service which provides @code{/etc/aliases},
17149 specifying how to deliver mail to users on this system.
17152 (service mail-aliases-service-type
17153 '(("postmaster" "bob")
17154 ("bob" "bob@@example.com" "bob@@example2.com")))
17158 The configuration for a @code{mail-aliases-service-type} service is an
17159 association list denoting how to deliver mail that comes to this
17160 system. Each entry is of the form @code{(alias addresses ...)}, with
17161 @code{alias} specifying the local alias and @code{addresses} specifying
17162 where to deliver this user's mail.
17164 The aliases aren't required to exist as users on the local system. In
17165 the above example, there doesn't need to be a @code{postmaster} entry in
17166 the @code{operating-system}'s @code{user-accounts} in order to deliver
17167 the @code{postmaster} mail to @code{bob} (which subsequently would
17168 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17170 @subsubheading GNU Mailutils IMAP4 Daemon
17171 @cindex GNU Mailutils IMAP4 Daemon
17173 @deffn {Scheme Variable} imap4d-service-type
17174 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17175 mailutils, GNU Mailutils Manual}), whose value should be an
17176 @code{imap4d-configuration} object as in this example:
17179 (service imap4d-service-type
17180 (imap4d-configuration
17181 (config-file (local-file "imap4d.conf"))))
17185 @deftp {Data Type} imap4d-configuration
17186 Data type representing the configuration of @command{imap4d}.
17189 @item @code{package} (default: @code{mailutils})
17190 The package that provides @command{imap4d}.
17192 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17193 File-like object of the configuration file to use, by default it will listen
17194 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17195 Mailutils Manual}, for details.
17200 @node Messaging Services
17201 @subsection Messaging Services
17206 The @code{(gnu services messaging)} module provides Guix service
17207 definitions for messaging services: currently only Prosody is supported.
17209 @subsubheading Prosody Service
17211 @deffn {Scheme Variable} prosody-service-type
17212 This is the type for the @uref{https://prosody.im, Prosody XMPP
17213 communication server}. Its value must be a @code{prosody-configuration}
17214 record as in this example:
17217 (service prosody-service-type
17218 (prosody-configuration
17219 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17222 (int-component-configuration
17223 (hostname "conference.example.net")
17225 (mod-muc (mod-muc-configuration)))))
17228 (virtualhost-configuration
17229 (domain "example.net"))))))
17232 See below for details about @code{prosody-configuration}.
17236 By default, Prosody does not need much configuration. Only one
17237 @code{virtualhosts} field is needed: it specifies the domain you wish
17240 You can perform various sanity checks on the generated configuration
17241 with the @code{prosodyctl check} command.
17243 Prosodyctl will also help you to import certificates from the
17244 @code{letsencrypt} directory so that the @code{prosody} user can access
17245 them. See @url{https://prosody.im/doc/letsencrypt}.
17248 prosodyctl --root cert import /etc/letsencrypt/live
17251 The available configuration parameters follow. Each parameter
17252 definition is preceded by its type; for example, @samp{string-list foo}
17253 indicates that the @code{foo} parameter should be specified as a list of
17254 strings. Types starting with @code{maybe-} denote parameters that won't
17255 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
17257 There is also a way to specify the configuration as a string, if you
17258 have an old @code{prosody.cfg.lua} file that you want to port over from
17259 some other system; see the end for more details.
17261 The @code{file-object} type designates either a file-like object
17262 (@pxref{G-Expressions, file-like objects}) or a file name.
17264 @c The following documentation was initially generated by
17265 @c (generate-documentation) in (gnu services messaging). Manually maintained
17266 @c documentation is better, so we shouldn't hesitate to edit below as
17267 @c needed. However if the change you want to make to this documentation
17268 @c can be done in an automated way, it's probably easier to change
17269 @c (generate-documentation) than to make it below and have to deal with
17270 @c the churn as Prosody updates.
17272 Available @code{prosody-configuration} fields are:
17274 @deftypevr {@code{prosody-configuration} parameter} package prosody
17275 The Prosody package.
17278 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
17279 Location of the Prosody data storage directory. See
17280 @url{https://prosody.im/doc/configure}.
17281 Defaults to @samp{"/var/lib/prosody"}.
17284 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
17285 Additional plugin directories. They are searched in all the specified
17286 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
17287 Defaults to @samp{()}.
17290 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
17291 Every virtual host and component needs a certificate so that clients and
17292 servers can securely verify its identity. Prosody will automatically load
17293 certificates/keys from the directory specified here.
17294 Defaults to @samp{"/etc/prosody/certs"}.
17297 @deftypevr {@code{prosody-configuration} parameter} string-list admins
17298 This is a list of accounts that are admins for the server. Note that you
17299 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
17300 @url{https://prosody.im/doc/creating_accounts}.
17301 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
17302 Defaults to @samp{()}.
17305 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
17306 Enable use of libevent for better performance under high load. See
17307 @url{https://prosody.im/doc/libevent}.
17308 Defaults to @samp{#f}.
17311 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
17312 This is the list of modules Prosody will load on startup. It looks for
17313 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
17314 Documentation on modules can be found at:
17315 @url{https://prosody.im/doc/modules}.
17316 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
17319 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
17320 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
17321 should you want to disable them then add them to this list.
17322 Defaults to @samp{()}.
17325 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
17326 Path to a text file where the shared groups are defined. If this path is
17327 empty then @samp{mod_groups} does nothing. See
17328 @url{https://prosody.im/doc/modules/mod_groups}.
17329 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
17332 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
17333 Disable account creation by default, for security. See
17334 @url{https://prosody.im/doc/creating_accounts}.
17335 Defaults to @samp{#f}.
17338 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
17339 These are the SSL/TLS-related settings. Most of them are disabled so to
17340 use Prosody's defaults. If you do not completely understand these options, do
17341 not add them to your config, it is easy to lower the security of your server
17342 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
17344 Available @code{ssl-configuration} fields are:
17346 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
17347 This determines what handshake to use.
17350 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
17351 Path to your private key file.
17354 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
17355 Path to your certificate file.
17358 @deftypevr {@code{ssl-configuration} parameter} file-object capath
17359 Path to directory containing root certificates that you wish Prosody to
17360 trust when verifying the certificates of remote servers.
17361 Defaults to @samp{"/etc/ssl/certs"}.
17364 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
17365 Path to a file containing root certificates that you wish Prosody to trust.
17366 Similar to @code{capath} but with all certificates concatenated together.
17369 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
17370 A list of verification options (these mostly map to OpenSSL's
17371 @code{set_verify()} flags).
17374 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
17375 A list of general options relating to SSL/TLS. These map to OpenSSL's
17376 @code{set_options()}. For a full list of options available in LuaSec, see the
17380 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
17381 How long a chain of certificate authorities to check when looking for a
17382 trusted root certificate.
17385 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
17386 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
17387 clients, and in what order.
17390 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
17391 A path to a file containing parameters for Diffie-Hellman key exchange. You
17392 can create such a file with:
17393 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
17396 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
17397 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
17398 @samp{"secp384r1"}.
17401 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
17402 A list of "extra" verification options.
17405 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
17406 Password for encrypted private keys.
17411 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
17412 Whether to force all client-to-server connections to be encrypted or not.
17413 See @url{https://prosody.im/doc/modules/mod_tls}.
17414 Defaults to @samp{#f}.
17417 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
17418 Set of mechanisms that will never be offered. See
17419 @url{https://prosody.im/doc/modules/mod_saslauth}.
17420 Defaults to @samp{("DIGEST-MD5")}.
17423 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
17424 Whether to force all server-to-server connections to be encrypted or not.
17425 See @url{https://prosody.im/doc/modules/mod_tls}.
17426 Defaults to @samp{#f}.
17429 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
17430 Whether to require encryption and certificate authentication. This
17431 provides ideal security, but requires servers you communicate with to support
17432 encryption AND present valid, trusted certificates. See
17433 @url{https://prosody.im/doc/s2s#security}.
17434 Defaults to @samp{#f}.
17437 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
17438 Many servers don't support encryption or have invalid or self-signed
17439 certificates. You can list domains here that will not be required to
17440 authenticate using certificates. They will be authenticated using DNS. See
17441 @url{https://prosody.im/doc/s2s#security}.
17442 Defaults to @samp{()}.
17445 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
17446 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
17447 valid certificates for some domains by specifying a list here. See
17448 @url{https://prosody.im/doc/s2s#security}.
17449 Defaults to @samp{()}.
17452 @deftypevr {@code{prosody-configuration} parameter} string authentication
17453 Select the authentication backend to use. The default provider stores
17454 passwords in plaintext and uses Prosody's configured data storage to store the
17455 authentication data. If you do not trust your server please see
17456 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
17457 about using the hashed backend. See also
17458 @url{https://prosody.im/doc/authentication}
17459 Defaults to @samp{"internal_plain"}.
17462 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
17463 Set logging options. Advanced logging configuration is not yet supported
17464 by the Prosody service. See @url{https://prosody.im/doc/logging}.
17465 Defaults to @samp{"*syslog"}.
17468 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
17469 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
17470 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
17473 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
17474 Maximum allowed size of the HTTP body (in bytes).
17477 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
17478 Some modules expose their own URL in various ways. This URL is built
17479 from the protocol, host and port used. If Prosody sits behind a proxy, the
17480 public URL will be @code{http-external-url} instead. See
17481 @url{https://prosody.im/doc/http#external_url}.
17484 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
17485 A host in Prosody is a domain on which user accounts can be created. For
17486 example if you want your users to have addresses like
17487 @samp{"john.smith@@example.com"} then you need to add a host
17488 @samp{"example.com"}. All options in this list will apply only to this host.
17490 Note: the name "virtual" host is used in configuration to avoid confusion with
17491 the actual physical host that Prosody is installed on. A single Prosody
17492 instance can serve many domains, each one defined as a VirtualHost entry in
17493 Prosody's configuration. Conversely a server that hosts a single domain would
17494 have just one VirtualHost entry.
17496 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17498 Available @code{virtualhost-configuration} fields are:
17500 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:
17501 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17502 Domain you wish Prosody to serve.
17507 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17508 Components are extra services on a server which are available to clients,
17509 usually on a subdomain of the main server (such as
17510 @samp{"mycomponent.example.com"}). Example components might be chatroom
17511 servers, user directories, or gateways to other protocols.
17513 Internal components are implemented with Prosody-specific plugins. To add an
17514 internal component, you simply fill the hostname field, and the plugin you wish
17515 to use for the component.
17517 See @url{https://prosody.im/doc/components}.
17518 Defaults to @samp{()}.
17520 Available @code{int-component-configuration} fields are:
17522 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:
17523 @deftypevr {@code{int-component-configuration} parameter} string hostname
17524 Hostname of the component.
17527 @deftypevr {@code{int-component-configuration} parameter} string plugin
17528 Plugin you wish to use for the component.
17531 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17532 Multi-user chat (MUC) is Prosody's module for allowing you to create
17533 hosted chatrooms/conferences for XMPP users.
17535 General information on setting up and using multi-user chatrooms can be found
17536 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17537 which you should read if you are new to XMPP chatrooms.
17539 See also @url{https://prosody.im/doc/modules/mod_muc}.
17541 Available @code{mod-muc-configuration} fields are:
17543 @deftypevr {@code{mod-muc-configuration} parameter} string name
17544 The name to return in service discovery responses.
17545 Defaults to @samp{"Prosody Chatrooms"}.
17548 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17549 If @samp{#t}, this will only allow admins to create new chatrooms.
17550 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17551 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17552 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17553 restricts to service administrators only.
17554 Defaults to @samp{#f}.
17557 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17558 Maximum number of history messages that will be sent to the member that has
17559 just joined the room.
17560 Defaults to @samp{20}.
17567 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17568 External components use XEP-0114, which most standalone components
17569 support. To add an external component, you simply fill the hostname field. See
17570 @url{https://prosody.im/doc/components}.
17571 Defaults to @samp{()}.
17573 Available @code{ext-component-configuration} fields are:
17575 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:
17576 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17577 Password which the component will use to log in.
17580 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17581 Hostname of the component.
17586 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17587 Port(s) Prosody listens on for component connections.
17588 Defaults to @samp{(5347)}.
17591 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17592 Interface Prosody listens on for component connections.
17593 Defaults to @samp{"127.0.0.1"}.
17596 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17597 Raw content that will be added to the configuration file.
17600 It could be that you just want to get a @code{prosody.cfg.lua}
17601 up and running. In that case, you can pass an
17602 @code{opaque-prosody-configuration} record as the value of
17603 @code{prosody-service-type}. As its name indicates, an opaque configuration
17604 does not have easy reflective capabilities.
17605 Available @code{opaque-prosody-configuration} fields are:
17607 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17608 The prosody package.
17611 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17612 The contents of the @code{prosody.cfg.lua} to use.
17615 For example, if your @code{prosody.cfg.lua} is just the empty
17616 string, you could instantiate a prosody service like this:
17619 (service prosody-service-type
17620 (opaque-prosody-configuration
17621 (prosody.cfg.lua "")))
17624 @c end of Prosody auto-generated documentation
17626 @subsubheading BitlBee Service
17628 @cindex IRC (Internet Relay Chat)
17629 @cindex IRC gateway
17630 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
17631 interface to a variety of messaging protocols such as XMPP.
17633 @defvr {Scheme Variable} bitlbee-service-type
17634 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
17635 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17638 To have BitlBee listen on port 6667 on localhost, add this line to your
17642 (service bitlbee-service-type)
17646 @deftp {Data Type} bitlbee-configuration
17647 This is the configuration for BitlBee, with the following fields:
17650 @item @code{interface} (default: @code{"127.0.0.1"})
17651 @itemx @code{port} (default: @code{6667})
17652 Listen on the network interface corresponding to the IP address
17653 specified in @var{interface}, on @var{port}.
17655 When @var{interface} is @code{127.0.0.1}, only local clients can
17656 connect; when it is @code{0.0.0.0}, connections can come from any
17657 networking interface.
17659 @item @code{package} (default: @code{bitlbee})
17660 The BitlBee package to use.
17662 @item @code{plugins} (default: @code{'()})
17663 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17665 @item @code{extra-settings} (default: @code{""})
17666 Configuration snippet added as-is to the BitlBee configuration file.
17670 @subsubheading Quassel Service
17672 @cindex IRC (Internet Relay Chat)
17673 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17674 meaning that one or more clients can attach to and detach from the
17677 @defvr {Scheme Variable} quassel-service-type
17678 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17679 IRC backend daemon. Its value is a @code{quassel-configuration}
17683 @deftp {Data Type} quassel-configuration
17684 This is the configuration for Quassel, with the following fields:
17687 @item @code{quassel} (default: @code{quassel})
17688 The Quassel package to use.
17690 @item @code{interface} (default: @code{"::,0.0.0.0"})
17691 @item @code{port} (default: @code{4242})
17692 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17693 interfaces specified in the comma delimited @var{interface}, on
17696 @item @code{loglevel} (default: @code{"Info"})
17697 The level of logging desired. Accepted values are Debug, Info, Warning
17702 @node Telephony Services
17703 @subsection Telephony Services
17705 @cindex Murmur (VoIP server)
17706 @cindex VoIP server
17707 This section describes how to set up and run a Murmur server. Murmur is
17708 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17711 @deftp {Data Type} murmur-configuration
17712 The service type for the Murmur server. An example configuration can
17716 (service murmur-service-type
17717 (murmur-configuration
17719 "Welcome to this Mumble server running on Guix!")
17720 (cert-required? #t) ;disallow text password logins
17721 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17722 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17725 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17726 password with the command that is printed during the activation phase.
17728 It is recommended to register a normal Mumble user account
17729 and grant it admin or moderator rights.
17730 You can use the @code{mumble} client to
17731 login as new normal user, register yourself, and log out.
17732 For the next step login with the name @code{SuperUser} use
17733 the @code{SuperUser} password that you set previously,
17734 and grant your newly registered mumble user administrator or moderator
17735 rights and create some channels.
17737 Available @code{murmur-configuration} fields are:
17740 @item @code{package} (default: @code{mumble})
17741 Package that contains @code{bin/murmurd}.
17743 @item @code{user} (default: @code{"murmur"})
17744 User who will run the Murmur server.
17746 @item @code{group} (default: @code{"murmur"})
17747 Group of the user who will run the murmur server.
17749 @item @code{port} (default: @code{64738})
17750 Port on which the server will listen.
17752 @item @code{welcome-text} (default: @code{""})
17753 Welcome text sent to clients when they connect.
17755 @item @code{server-password} (default: @code{""})
17756 Password the clients have to enter in order to connect.
17758 @item @code{max-users} (default: @code{100})
17759 Maximum of users that can be connected to the server at once.
17761 @item @code{max-user-bandwidth} (default: @code{#f})
17762 Maximum voice traffic a user can send per second.
17764 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17765 File name of the sqlite database.
17766 The service's user will become the owner of the directory.
17768 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17769 File name of the log file.
17770 The service's user will become the owner of the directory.
17772 @item @code{autoban-attempts} (default: @code{10})
17773 Maximum number of logins a user can make in @code{autoban-timeframe}
17774 without getting auto banned for @code{autoban-time}.
17776 @item @code{autoban-timeframe} (default: @code{120})
17777 Timeframe for autoban in seconds.
17779 @item @code{autoban-time} (default: @code{300})
17780 Amount of time in seconds for which a client gets banned
17781 when violating the autoban limits.
17783 @item @code{opus-threshold} (default: @code{100})
17784 Percentage of clients that need to support opus
17785 before switching over to opus audio codec.
17787 @item @code{channel-nesting-limit} (default: @code{10})
17788 How deep channels can be nested at maximum.
17790 @item @code{channelname-regex} (default: @code{#f})
17791 A string in form of a Qt regular expression that channel names must conform to.
17793 @item @code{username-regex} (default: @code{#f})
17794 A string in form of a Qt regular expression that user names must conform to.
17796 @item @code{text-message-length} (default: @code{5000})
17797 Maximum size in bytes that a user can send in one text chat message.
17799 @item @code{image-message-length} (default: @code{(* 128 1024)})
17800 Maximum size in bytes that a user can send in one image message.
17802 @item @code{cert-required?} (default: @code{#f})
17803 If it is set to @code{#t} clients that use weak password authentication
17804 will not be accepted. Users must have completed the certificate wizard to join.
17806 @item @code{remember-channel?} (default: @code{#f})
17807 Should murmur remember the last channel each user was in when they disconnected
17808 and put them into the remembered channel when they rejoin.
17810 @item @code{allow-html?} (default: @code{#f})
17811 Should html be allowed in text messages, user comments, and channel descriptions.
17813 @item @code{allow-ping?} (default: @code{#f})
17814 Setting to true exposes the current user count, the maximum user count, and
17815 the server's maximum bandwidth per client to unauthenticated users. In the
17816 Mumble client, this information is shown in the Connect dialog.
17818 Disabling this setting will prevent public listing of the server.
17820 @item @code{bonjour?} (default: @code{#f})
17821 Should the server advertise itself in the local network through the bonjour protocol.
17823 @item @code{send-version?} (default: @code{#f})
17824 Should the murmur server version be exposed in ping requests.
17826 @item @code{log-days} (default: @code{31})
17827 Murmur also stores logs in the database, which are accessible via RPC.
17828 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17829 or -1 to disable logging to the database.
17831 @item @code{obfuscate-ips?} (default: @code{#t})
17832 Should logged ips be obfuscated to protect the privacy of users.
17834 @item @code{ssl-cert} (default: @code{#f})
17835 File name of the SSL/TLS certificate used for encrypted connections.
17838 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17840 @item @code{ssl-key} (default: @code{#f})
17841 Filepath to the ssl private key used for encrypted connections.
17843 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17846 @item @code{ssl-dh-params} (default: @code{#f})
17847 File name of a PEM-encoded file with Diffie-Hellman parameters
17848 for the SSL/TLS encryption. Alternatively you set it to
17849 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17850 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17852 @item @code{ssl-ciphers} (default: @code{#f})
17853 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17856 This option is specified using
17857 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17858 OpenSSL cipher list notation}.
17860 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17861 before setting it here, to get a feel for which cipher suites you will get.
17862 After setting this option, it is recommend that you inspect your Murmur log
17863 to ensure that Murmur is using the cipher suites that you expected it to.
17865 Note: Changing this option may impact the backwards compatibility of your
17866 Murmur server, and can remove the ability for older Mumble clients to be able
17869 @item @code{public-registration} (default: @code{#f})
17870 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17872 You can optionally register your server in the public server list that the
17873 @code{mumble} client shows on startup.
17874 You cannot register your server if you have set a @code{server-password},
17875 or set @code{allow-ping} to @code{#f}.
17877 It might take a few hours until it shows up in the public list.
17879 @item @code{file} (default: @code{#f})
17880 Optional alternative override for this configuration.
17884 @deftp {Data Type} murmur-public-registration-configuration
17885 Configuration for public registration of a murmur service.
17889 This is a display name for your server. Not to be confused with the hostname.
17891 @item @code{password}
17892 A password to identify your registration.
17893 Subsequent updates will need the same password. Don't lose your password.
17896 This should be a @code{http://} or @code{https://} link to your web
17899 @item @code{hostname} (default: @code{#f})
17900 By default your server will be listed by its IP address.
17901 If it is set your server will be linked by this host name instead.
17907 @node Monitoring Services
17908 @subsection Monitoring Services
17910 @subsubheading Tailon Service
17912 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17913 viewing and searching log files.
17915 The following example will configure the service with default values.
17916 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17919 (service tailon-service-type)
17922 The following example customises more of the Tailon configuration,
17923 adding @command{sed} to the list of allowed commands.
17926 (service tailon-service-type
17927 (tailon-configuration
17929 (tailon-configuration-file
17930 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17934 @deftp {Data Type} tailon-configuration
17935 Data type representing the configuration of Tailon.
17936 This type has the following parameters:
17939 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17940 The configuration file to use for Tailon. This can be set to a
17941 @dfn{tailon-configuration-file} record value, or any gexp
17942 (@pxref{G-Expressions}).
17944 For example, to instead use a local file, the @code{local-file} function
17948 (service tailon-service-type
17949 (tailon-configuration
17950 (config-file (local-file "./my-tailon.conf"))))
17953 @item @code{package} (default: @code{tailon})
17954 The tailon package to use.
17959 @deftp {Data Type} tailon-configuration-file
17960 Data type representing the configuration options for Tailon.
17961 This type has the following parameters:
17964 @item @code{files} (default: @code{(list "/var/log")})
17965 List of files to display. The list can include strings for a single file
17966 or directory, or a list, where the first item is the name of a
17967 subsection, and the remaining items are the files or directories in that
17970 @item @code{bind} (default: @code{"localhost:8080"})
17971 Address and port to which Tailon should bind on.
17973 @item @code{relative-root} (default: @code{#f})
17974 URL path to use for Tailon, set to @code{#f} to not use a path.
17976 @item @code{allow-transfers?} (default: @code{#t})
17977 Allow downloading the log files in the web interface.
17979 @item @code{follow-names?} (default: @code{#t})
17980 Allow tailing of not-yet existent files.
17982 @item @code{tail-lines} (default: @code{200})
17983 Number of lines to read initially from each file.
17985 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17986 Commands to allow running. By default, @code{sed} is disabled.
17988 @item @code{debug?} (default: @code{#f})
17989 Set @code{debug?} to @code{#t} to show debug messages.
17991 @item @code{wrap-lines} (default: @code{#t})
17992 Initial line wrapping state in the web interface. Set to @code{#t} to
17993 initially wrap lines (the default), or to @code{#f} to initially not
17996 @item @code{http-auth} (default: @code{#f})
17997 HTTP authentication type to use. Set to @code{#f} to disable
17998 authentication (the default). Supported values are @code{"digest"} or
18001 @item @code{users} (default: @code{#f})
18002 If HTTP authentication is enabled (see @code{http-auth}), access will be
18003 restricted to the credentials provided here. To configure users, use a
18004 list of pairs, where the first element of the pair is the username, and
18005 the 2nd element of the pair is the password.
18008 (tailon-configuration-file
18009 (http-auth "basic")
18010 (users '(("user1" . "password1")
18011 ("user2" . "password2"))))
18018 @subsubheading Darkstat Service
18020 Darkstat is a packet sniffer that captures network traffic, calculates
18021 statistics about usage, and serves reports over HTTP.
18023 @defvar {Scheme Variable} darkstat-service-type
18024 This is the service type for the
18025 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18026 service, its value must be a @code{darkstat-configuration} record as in
18030 (service darkstat-service-type
18031 (darkstat-configuration
18032 (interface "eno1")))
18036 @deftp {Data Type} darkstat-configuration
18037 Data type representing the configuration of @command{darkstat}.
18040 @item @code{package} (default: @code{darkstat})
18041 The darkstat package to use.
18043 @item @code{interface}
18044 Capture traffic on the specified network interface.
18046 @item @code{port} (default: @code{"667"})
18047 Bind the web interface to the specified port.
18049 @item @code{bind-address} (default: @code{"127.0.0.1"})
18050 Bind the web interface to the specified address.
18052 @item @code{base} (default: @code{"/"})
18053 Specify the path of the base URL. This can be useful if
18054 @command{darkstat} is accessed via a reverse proxy.
18059 @subsubheading Prometheus Node Exporter Service
18061 @cindex prometheus-node-exporter
18062 The Prometheus ``node exporter'' makes hardware and operating system statistics
18063 provided by the Linux kernel available for the Prometheus monitoring system.
18064 This service should be deployed on all physical nodes and virtual machines,
18065 where monitoring these statistics is desirable.
18067 @defvar {Scheme variable} prometheus-node-exporter-service-type
18068 This is the service type for the
18069 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18070 service, its value must be a @code{prometheus-node-exporter-configuration}
18071 record as in this example:
18074 (service prometheus-node-exporter-service-type
18075 (prometheus-node-exporter-configuration
18076 (web-listen-address ":9100")))
18080 @deftp {Data Type} prometheus-node-exporter-configuration
18081 Data type representing the configuration of @command{node_exporter}.
18084 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18085 The prometheus-node-exporter package to use.
18087 @item @code{web-listen-address} (default: @code{":9100"})
18088 Bind the web interface to the specified address.
18093 @subsubheading Zabbix server
18094 @cindex zabbix zabbix-server
18095 Zabbix provides monitoring metrics, among others network utilization, CPU load
18096 and disk space consumption:
18099 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18100 @item Auto-discovery of servers and network devices and interfaces.
18101 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18102 @item Distributed monitoring with centralized web administration.
18103 @item Native high performance agents.
18104 @item SLA, and ITIL KPI metrics on reporting.
18105 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18106 @item Remote command execution through Zabbix proxies.
18109 @c %start of fragment
18111 Available @code{zabbix-server-configuration} fields are:
18113 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18114 The zabbix-server package.
18118 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18119 User who will run the Zabbix server.
18121 Defaults to @samp{"zabbix"}.
18125 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18126 Group who will run the Zabbix server.
18128 Defaults to @samp{"zabbix"}.
18132 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18133 Database host name.
18135 Defaults to @samp{"127.0.0.1"}.
18139 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18142 Defaults to @samp{"zabbix"}.
18146 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18149 Defaults to @samp{"zabbix"}.
18153 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18154 Database password. Please, use @code{include-files} with
18155 @code{DBPassword=SECRET} inside a specified file instead.
18157 Defaults to @samp{""}.
18161 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18164 Defaults to @samp{5432}.
18168 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18169 Specifies where log messages are written to:
18173 @code{system} - syslog.
18176 @code{file} - file specified with @code{log-file} parameter.
18179 @code{console} - standard output.
18183 Defaults to @samp{""}.
18187 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18188 Log file name for @code{log-type} @code{file} parameter.
18190 Defaults to @samp{"/var/log/zabbix/server.log"}.
18194 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18197 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18201 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18202 The location of certificate authority (CA) files for SSL server
18203 certificate verification.
18205 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18209 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18210 Location of SSL client certificates.
18212 Defaults to @samp{"/etc/ssl/certs"}.
18216 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18217 Extra options will be appended to Zabbix server configuration file.
18219 Defaults to @samp{""}.
18223 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18224 You may include individual files or all files in a directory in the
18225 configuration file.
18227 Defaults to @samp{()}.
18231 @c %end of fragment
18233 @subsubheading Zabbix agent
18234 @cindex zabbix zabbix-agent
18236 Zabbix agent gathers information for Zabbix server.
18238 @c %start of fragment
18240 Available @code{zabbix-agent-configuration} fields are:
18242 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
18243 The zabbix-agent package.
18247 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
18248 User who will run the Zabbix agent.
18250 Defaults to @samp{"zabbix"}.
18254 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
18255 Group who will run the Zabbix agent.
18257 Defaults to @samp{"zabbix"}.
18261 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
18262 Unique, case sensitive hostname which is required for active checks and
18263 must match hostname as configured on the server.
18265 Defaults to @samp{"Zabbix server"}.
18269 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
18270 Specifies where log messages are written to:
18274 @code{system} - syslog.
18277 @code{file} - file specified with @code{log-file} parameter.
18280 @code{console} - standard output.
18284 Defaults to @samp{""}.
18288 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
18289 Log file name for @code{log-type} @code{file} parameter.
18291 Defaults to @samp{"/var/log/zabbix/agent.log"}.
18295 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
18298 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
18302 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
18303 List of IP addresses, optionally in CIDR notation, or hostnames of
18304 Zabbix servers and Zabbix proxies. Incoming connections will be
18305 accepted only from the hosts listed here.
18307 Defaults to @samp{("127.0.0.1")}.
18311 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
18312 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
18313 proxies for active checks. If port is not specified, default port is
18314 used. If this parameter is not specified, active checks are disabled.
18316 Defaults to @samp{("127.0.0.1")}.
18320 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
18321 Extra options will be appended to Zabbix server configuration file.
18323 Defaults to @samp{""}.
18327 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
18328 You may include individual files or all files in a directory in the
18329 configuration file.
18331 Defaults to @samp{()}.
18335 @c %end of fragment
18337 @subsubheading Zabbix front-end
18338 @cindex zabbix zabbix-front-end
18340 This service provides a WEB interface to Zabbix server.
18342 @c %start of fragment
18344 Available @code{zabbix-front-end-configuration} fields are:
18346 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
18347 NGINX configuration.
18351 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
18352 Database host name.
18354 Defaults to @samp{"localhost"}.
18358 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
18361 Defaults to @samp{5432}.
18365 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
18368 Defaults to @samp{"zabbix"}.
18372 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
18375 Defaults to @samp{"zabbix"}.
18379 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
18380 Database password. Please, use @code{db-secret-file} instead.
18382 Defaults to @samp{""}.
18386 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
18387 Secret file which will be appended to @file{zabbix.conf.php} file. This
18388 file contains credentials for use by Zabbix front-end. You are expected
18389 to create it manually.
18391 Defaults to @samp{""}.
18395 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
18396 Zabbix server hostname.
18398 Defaults to @samp{"localhost"}.
18402 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
18403 Zabbix server port.
18405 Defaults to @samp{10051}.
18410 @c %end of fragment
18412 @node Kerberos Services
18413 @subsection Kerberos Services
18416 The @code{(gnu services kerberos)} module provides services relating to
18417 the authentication protocol @dfn{Kerberos}.
18419 @subsubheading Krb5 Service
18421 Programs using a Kerberos client library normally
18422 expect a configuration file in @file{/etc/krb5.conf}.
18423 This service generates such a file from a definition provided in the
18424 operating system declaration.
18425 It does not cause any daemon to be started.
18427 No ``keytab'' files are provided by this service---you must explicitly create them.
18428 This service is known to work with the MIT client library, @code{mit-krb5}.
18429 Other implementations have not been tested.
18431 @defvr {Scheme Variable} krb5-service-type
18432 A service type for Kerberos 5 clients.
18436 Here is an example of its use:
18438 (service krb5-service-type
18439 (krb5-configuration
18440 (default-realm "EXAMPLE.COM")
18441 (allow-weak-crypto? #t)
18444 (name "EXAMPLE.COM")
18445 (admin-server "groucho.example.com")
18446 (kdc "karl.example.com"))
18449 (admin-server "kerb-admin.argrx.edu")
18450 (kdc "keys.argrx.edu"))))))
18454 This example provides a Kerberos@tie{}5 client configuration which:
18456 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
18457 of which have distinct administration servers and key distribution centers;
18458 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
18459 specified by clients;
18460 @item Accepts services which only support encryption types known to be weak.
18463 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
18464 Only the most commonly used ones are described here.
18465 For a full list, and more detailed explanation of each, see the MIT
18466 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
18470 @deftp {Data Type} krb5-realm
18471 @cindex realm, kerberos
18474 This field is a string identifying the name of the realm.
18475 A common convention is to use the fully qualified DNS name of your organization,
18476 converted to upper case.
18478 @item @code{admin-server}
18479 This field is a string identifying the host where the administration server is
18483 This field is a string identifying the key distribution center
18488 @deftp {Data Type} krb5-configuration
18491 @item @code{allow-weak-crypto?} (default: @code{#f})
18492 If this flag is @code{#t} then services which only offer encryption algorithms
18493 known to be weak will be accepted.
18495 @item @code{default-realm} (default: @code{#f})
18496 This field should be a string identifying the default Kerberos
18497 realm for the client.
18498 You should set this field to the name of your Kerberos realm.
18499 If this value is @code{#f}
18500 then a realm must be specified with every Kerberos principal when invoking programs
18501 such as @command{kinit}.
18503 @item @code{realms}
18504 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18506 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18512 @subsubheading PAM krb5 Service
18515 The @code{pam-krb5} service allows for login authentication and password
18516 management via Kerberos.
18517 You will need this service if you want PAM enabled applications to authenticate
18518 users using Kerberos.
18520 @defvr {Scheme Variable} pam-krb5-service-type
18521 A service type for the Kerberos 5 PAM module.
18524 @deftp {Data Type} pam-krb5-configuration
18525 Data type representing the configuration of the Kerberos 5 PAM module.
18526 This type has the following parameters:
18528 @item @code{pam-krb5} (default: @code{pam-krb5})
18529 The pam-krb5 package to use.
18531 @item @code{minimum-uid} (default: @code{1000})
18532 The smallest user ID for which Kerberos authentications should be attempted.
18533 Local accounts with lower values will silently fail to authenticate.
18538 @node LDAP Services
18539 @subsection LDAP Services
18541 @cindex nslcd, LDAP service
18543 The @code{(gnu services authentication)} module provides the
18544 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18545 server. In addition to configuring the service itself, you may want to add
18546 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18547 Switch} for detailed information.
18549 Here is a simple operating system declaration with a default configuration of
18550 the @code{nslcd-service-type} and a Name Service Switch configuration that
18551 consults the @code{ldap} name service last:
18554 (use-service-modules authentication)
18555 (use-modules (gnu system nss))
18561 (service nslcd-service-type)
18562 (service dhcp-client-service-type)
18564 (name-service-switch
18565 (let ((services (list (name-service (name "db"))
18566 (name-service (name "files"))
18567 (name-service (name "ldap")))))
18568 (name-service-switch
18569 (inherit %mdns-host-lookup-nss)
18570 (password services)
18573 (netgroup services)
18574 (gshadow services)))))
18577 @c %start of generated documentation for nslcd-configuration
18579 Available @code{nslcd-configuration} fields are:
18581 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18582 The @code{nss-pam-ldapd} package to use.
18586 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18587 The number of threads to start that can handle requests and perform LDAP
18588 queries. Each thread opens a separate connection to the LDAP server.
18589 The default is to start 5 threads.
18591 Defaults to @samp{disabled}.
18595 @deftypevr {@code{nslcd-configuration} parameter} string uid
18596 This specifies the user id with which the daemon should be run.
18598 Defaults to @samp{"nslcd"}.
18602 @deftypevr {@code{nslcd-configuration} parameter} string gid
18603 This specifies the group id with which the daemon should be run.
18605 Defaults to @samp{"nslcd"}.
18609 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18610 This option controls the way logging is done via a list containing
18611 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18612 or "syslog", or an absolute file name. The LEVEL argument is optional
18613 and specifies the log level. The log level may be one of the following
18614 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18615 messages with the specified log level or higher are logged.
18617 Defaults to @samp{("/var/log/nslcd" info)}.
18621 @deftypevr {@code{nslcd-configuration} parameter} list uri
18622 The list of LDAP server URIs. Normally, only the first server will be
18623 used with the following servers as fall-back.
18625 Defaults to @samp{("ldap://localhost:389/")}.
18629 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18630 The version of the LDAP protocol to use. The default is to use the
18631 maximum version supported by the LDAP library.
18633 Defaults to @samp{disabled}.
18637 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18638 Specifies the distinguished name with which to bind to the directory
18639 server for lookups. The default is to bind anonymously.
18641 Defaults to @samp{disabled}.
18645 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18646 Specifies the credentials with which to bind. This option is only
18647 applicable when used with binddn.
18649 Defaults to @samp{disabled}.
18653 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18654 Specifies the distinguished name to use when the root user tries to
18655 modify a user's password using the PAM module.
18657 Defaults to @samp{disabled}.
18661 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18662 Specifies the credentials with which to bind if the root user tries to
18663 change a user's password. This option is only applicable when used with
18666 Defaults to @samp{disabled}.
18670 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18671 Specifies the SASL mechanism to be used when performing SASL
18674 Defaults to @samp{disabled}.
18678 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18679 Specifies the SASL realm to be used when performing SASL authentication.
18681 Defaults to @samp{disabled}.
18685 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18686 Specifies the authentication identity to be used when performing SASL
18689 Defaults to @samp{disabled}.
18693 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18694 Specifies the authorization identity to be used when performing SASL
18697 Defaults to @samp{disabled}.
18701 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18702 Determines whether the LDAP server host name should be canonicalised. If
18703 this is enabled the LDAP library will do a reverse host name lookup. By
18704 default, it is left up to the LDAP library whether this check is
18707 Defaults to @samp{disabled}.
18711 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18712 Set the name for the GSS-API Kerberos credentials cache.
18714 Defaults to @samp{disabled}.
18718 @deftypevr {@code{nslcd-configuration} parameter} string base
18719 The directory search base.
18721 Defaults to @samp{"dc=example,dc=com"}.
18725 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18726 Specifies the search scope (subtree, onelevel, base or children). The
18727 default scope is subtree; base scope is almost never useful for name
18728 service lookups; children scope is not supported on all servers.
18730 Defaults to @samp{(subtree)}.
18734 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18735 Specifies the policy for dereferencing aliases. The default policy is
18736 to never dereference aliases.
18738 Defaults to @samp{disabled}.
18742 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18743 Specifies whether automatic referral chasing should be enabled. The
18744 default behaviour is to chase referrals.
18746 Defaults to @samp{disabled}.
18750 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18751 This option allows for custom attributes to be looked up instead of the
18752 default RFC 2307 attributes. It is a list of maps, each consisting of
18753 the name of a map, the RFC 2307 attribute to match and the query
18754 expression for the attribute as it is available in the directory.
18756 Defaults to @samp{()}.
18760 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18761 A list of filters consisting of the name of a map to which the filter
18762 applies and an LDAP search filter expression.
18764 Defaults to @samp{()}.
18768 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18769 Specifies the time limit in seconds to use when connecting to the
18770 directory server. The default value is 10 seconds.
18772 Defaults to @samp{disabled}.
18776 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18777 Specifies the time limit (in seconds) to wait for a response from the
18778 LDAP server. A value of zero, which is the default, is to wait
18779 indefinitely for searches to be completed.
18781 Defaults to @samp{disabled}.
18785 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18786 Specifies the period if inactivity (in seconds) after which the con‐
18787 nection to the LDAP server will be closed. The default is not to time
18790 Defaults to @samp{disabled}.
18794 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18795 Specifies the number of seconds to sleep when connecting to all LDAP
18796 servers fails. By default one second is waited between the first
18797 failure and the first retry.
18799 Defaults to @samp{disabled}.
18803 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18804 Specifies the time after which the LDAP server is considered to be
18805 permanently unavailable. Once this time is reached retries will be done
18806 only once per this time period. The default value is 10 seconds.
18808 Defaults to @samp{disabled}.
18812 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18813 Specifies whether to use SSL/TLS or not (the default is not to). If
18814 'start-tls is specified then StartTLS is used rather than raw LDAP over
18817 Defaults to @samp{disabled}.
18821 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18822 Specifies what checks to perform on a server-supplied certificate. The
18823 meaning of the values is described in the ldap.conf(5) manual page.
18825 Defaults to @samp{disabled}.
18829 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18830 Specifies the directory containing X.509 certificates for peer authen‐
18831 tication. This parameter is ignored when using GnuTLS.
18833 Defaults to @samp{disabled}.
18837 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18838 Specifies the path to the X.509 certificate for peer authentication.
18840 Defaults to @samp{disabled}.
18844 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18845 Specifies the path to an entropy source. This parameter is ignored when
18848 Defaults to @samp{disabled}.
18852 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18853 Specifies the ciphers to use for TLS as a string.
18855 Defaults to @samp{disabled}.
18859 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18860 Specifies the path to the file containing the local certificate for
18861 client TLS authentication.
18863 Defaults to @samp{disabled}.
18867 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18868 Specifies the path to the file containing the private key for client TLS
18871 Defaults to @samp{disabled}.
18875 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18876 Set this to a number greater than 0 to request paged results from the
18877 LDAP server in accordance with RFC2696. The default (0) is to not
18878 request paged results.
18880 Defaults to @samp{disabled}.
18884 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18885 This option prevents group membership lookups through LDAP for the
18886 specified users. Alternatively, the value 'all-local may be used. With
18887 that value nslcd builds a full list of non-LDAP users on startup.
18889 Defaults to @samp{disabled}.
18893 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18894 This option ensures that LDAP users with a numeric user id lower than
18895 the specified value are ignored.
18897 Defaults to @samp{disabled}.
18901 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18902 This option specifies an offset that is added to all LDAP numeric user
18903 ids. This can be used to avoid user id collisions with local users.
18905 Defaults to @samp{disabled}.
18909 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18910 This option specifies an offset that is added to all LDAP numeric group
18911 ids. This can be used to avoid user id collisions with local groups.
18913 Defaults to @samp{disabled}.
18917 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18918 If this option is set, the member attribute of a group may point to
18919 another group. Members of nested groups are also returned in the higher
18920 level group and parent groups are returned when finding groups for a
18921 specific user. The default is not to perform extra searches for nested
18924 Defaults to @samp{disabled}.
18928 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18929 If this option is set, the group member list is not retrieved when
18930 looking up groups. Lookups for finding which groups a user belongs to
18931 will remain functional so the user will likely still get the correct
18932 groups assigned on login.
18934 Defaults to @samp{disabled}.
18938 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18939 If this option is set, functions which cause all user/group entries to
18940 be loaded from the directory will not succeed in doing so. This can
18941 dramatically reduce LDAP server load in situations where there are a
18942 great number of users and/or groups. This option is not recommended for
18943 most configurations.
18945 Defaults to @samp{disabled}.
18949 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18950 This option can be used to specify how user and group names are verified
18951 within the system. This pattern is used to check all user and group
18952 names that are requested and returned from LDAP.
18954 Defaults to @samp{disabled}.
18958 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18959 This specifies whether or not to perform searches using case-insensitive
18960 matching. Enabling this could open up the system to authorization
18961 bypass vulnerabilities and introduce nscd cache poisoning
18962 vulnerabilities which allow denial of service.
18964 Defaults to @samp{disabled}.
18968 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18969 This option specifies whether password policy controls are requested and
18970 handled from the LDAP server when performing user authentication.
18972 Defaults to @samp{disabled}.
18976 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18977 By default nslcd performs an LDAP search with the user's credentials
18978 after BIND (authentication) to ensure that the BIND operation was
18979 successful. The default search is a simple check to see if the user's
18980 DN exists. A search filter can be specified that will be used instead.
18981 It should return at least one entry.
18983 Defaults to @samp{disabled}.
18987 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18988 This option allows flexible fine tuning of the authorisation check that
18989 should be performed. The search filter specified is executed and if any
18990 entries match, access is granted, otherwise access is denied.
18992 Defaults to @samp{disabled}.
18996 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18997 If this option is set password modification using pam_ldap will be
18998 denied and the specified message will be presented to the user instead.
18999 The message can be used to direct the user to an alternative means of
19000 changing their password.
19002 Defaults to @samp{disabled}.
19006 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19007 List of pam service names for which LDAP authentication should suffice.
19009 Defaults to @samp{()}.
19013 @c %end of generated documentation for nslcd-configuration
19017 @subsection Web Services
19022 The @code{(gnu services web)} module provides the Apache HTTP Server,
19023 the nginx web server, and also a fastcgi wrapper daemon.
19025 @subsubheading Apache HTTP Server
19027 @deffn {Scheme Variable} httpd-service-type
19028 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19029 (@dfn{httpd}). The value for this service type is a
19030 @code{httpd-configuration} record.
19032 A simple example configuration is given below.
19035 (service httpd-service-type
19036 (httpd-configuration
19039 (server-name "www.example.com")
19040 (document-root "/srv/http/www.example.com")))))
19043 Other services can also extend the @code{httpd-service-type} to add to
19047 (simple-service 'my-extra-server httpd-service-type
19051 (list (string-append
19052 "ServerName "www.example.com
19053 DocumentRoot \"/srv/http/www.example.com\"")))))
19057 The details for the @code{httpd-configuration}, @code{httpd-module},
19058 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19061 @deffn {Data Type} httpd-configuration
19062 This data type represents the configuration for the httpd service.
19065 @item @code{package} (default: @code{httpd})
19066 The httpd package to use.
19068 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19069 The pid file used by the shepherd-service.
19071 @item @code{config} (default: @code{(httpd-config-file)})
19072 The configuration file to use with the httpd service. The default value
19073 is a @code{httpd-config-file} record, but this can also be a different
19074 G-expression that generates a file, for example a @code{plain-file}. A
19075 file outside of the store can also be specified through a string.
19080 @deffn {Data Type} httpd-module
19081 This data type represents a module for the httpd service.
19085 The name of the module.
19088 The file for the module. This can be relative to the httpd package being
19089 used, the absolute location of a file, or a G-expression for a file
19090 within the store, for example @code{(file-append mod-wsgi
19091 "/modules/mod_wsgi.so")}.
19096 @defvr {Scheme Variable} %default-httpd-modules
19097 A default list of @code{httpd-module} objects.
19100 @deffn {Data Type} httpd-config-file
19101 This data type represents a configuration file for the httpd service.
19104 @item @code{modules} (default: @code{%default-httpd-modules})
19105 The modules to load. Additional modules can be added here, or loaded by
19106 additional configuration.
19108 For example, in order to handle requests for PHP files, you can use Apache’s
19109 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19112 (service httpd-service-type
19113 (httpd-configuration
19118 (name "proxy_module")
19119 (file "modules/mod_proxy.so"))
19121 (name "proxy_fcgi_module")
19122 (file "modules/mod_proxy_fcgi.so"))
19123 %default-httpd-modules))
19124 (extra-config (list "\
19125 <FilesMatch \\.php$>
19126 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19127 </FilesMatch>"))))))
19128 (service php-fpm-service-type
19129 (php-fpm-configuration
19130 (socket "/var/run/php-fpm.sock")
19131 (socket-group "httpd")))
19134 @item @code{server-root} (default: @code{httpd})
19135 The @code{ServerRoot} in the configuration file, defaults to the httpd
19136 package. Directives including @code{Include} and @code{LoadModule} are
19137 taken as relative to the server root.
19139 @item @code{server-name} (default: @code{#f})
19140 The @code{ServerName} in the configuration file, used to specify the
19141 request scheme, hostname and port that the server uses to identify
19144 This doesn't need to be set in the server config, and can be specifyed
19145 in virtual hosts. The default is @code{#f} to not specify a
19148 @item @code{document-root} (default: @code{"/srv/http"})
19149 The @code{DocumentRoot} from which files will be served.
19151 @item @code{listen} (default: @code{'("80")})
19152 The list of values for the @code{Listen} directives in the config
19153 file. The value should be a list of strings, when each string can
19154 specify the port number to listen on, and optionally the IP address and
19157 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19158 The @code{PidFile} to use. This should match the @code{pid-file} set in
19159 the @code{httpd-configuration} so that the Shepherd service is
19160 configured correctly.
19162 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19163 The @code{ErrorLog} to which the server will log errors.
19165 @item @code{user} (default: @code{"httpd"})
19166 The @code{User} which the server will answer requests as.
19168 @item @code{group} (default: @code{"httpd"})
19169 The @code{Group} which the server will answer requests as.
19171 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19172 A flat list of strings and G-expressions which will be added to the end
19173 of the configuration file.
19175 Any values which the service is extended with will be appended to this
19181 @deffn {Data Type} httpd-virtualhost
19182 This data type represents a virtualhost configuration block for the httpd service.
19184 These should be added to the extra-config for the httpd-service.
19187 (simple-service 'my-extra-server httpd-service-type
19191 (list (string-append
19192 "ServerName "www.example.com
19193 DocumentRoot \"/srv/http/www.example.com\"")))))
19197 @item @code{addresses-and-ports}
19198 The addresses and ports for the @code{VirtualHost} directive.
19200 @item @code{contents}
19201 The contents of the @code{VirtualHost} directive, this should be a list
19202 of strings and G-expressions.
19207 @subsubheading NGINX
19209 @deffn {Scheme Variable} nginx-service-type
19210 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19211 value for this service type is a @code{<nginx-configuration>} record.
19213 A simple example configuration is given below.
19216 (service nginx-service-type
19217 (nginx-configuration
19219 (list (nginx-server-configuration
19220 (server-name '("www.example.com"))
19221 (root "/srv/http/www.example.com"))))))
19224 In addition to adding server blocks to the service configuration
19225 directly, this service can be extended by other services to add server
19226 blocks, as in this example:
19229 (simple-service 'my-extra-server nginx-service-type
19230 (list (nginx-server-configuration
19231 (root "/srv/http/extra-website")
19232 (try-files (list "$uri" "$uri/index.html")))))
19236 At startup, @command{nginx} has not yet read its configuration file, so
19237 it uses a default file to log error messages. If it fails to load its
19238 configuration file, that is where error messages are logged. After the
19239 configuration file is loaded, the default error log file changes as per
19240 configuration. In our case, startup error messages can be found in
19241 @file{/var/run/nginx/logs/error.log}, and after configuration in
19242 @file{/var/log/nginx/error.log}. The second location can be changed
19243 with the @var{log-directory} configuration option.
19245 @deffn {Data Type} nginx-configuration
19246 This data type represents the configuration for NGinx. Some
19247 configuration can be done through this and the other provided record
19248 types, or alternatively, a config file can be provided.
19251 @item @code{nginx} (default: @code{nginx})
19252 The nginx package to use.
19254 @item @code{log-directory} (default: @code{"/var/log/nginx"})
19255 The directory to which NGinx will write log files.
19257 @item @code{run-directory} (default: @code{"/var/run/nginx"})
19258 The directory in which NGinx will create a pid file, and write temporary
19261 @item @code{server-blocks} (default: @code{'()})
19262 A list of @dfn{server blocks} to create in the generated configuration
19263 file, the elements should be of type
19264 @code{<nginx-server-configuration>}.
19266 The following example would setup NGinx to serve @code{www.example.com}
19267 from the @code{/srv/http/www.example.com} directory, without using
19270 (service nginx-service-type
19271 (nginx-configuration
19273 (list (nginx-server-configuration
19274 (server-name '("www.example.com"))
19275 (root "/srv/http/www.example.com"))))))
19278 @item @code{upstream-blocks} (default: @code{'()})
19279 A list of @dfn{upstream blocks} to create in the generated configuration
19280 file, the elements should be of type
19281 @code{<nginx-upstream-configuration>}.
19283 Configuring upstreams through the @code{upstream-blocks} can be useful
19284 when combined with @code{locations} in the
19285 @code{<nginx-server-configuration>} records. The following example
19286 creates a server configuration with one location configuration, that
19287 will proxy requests to a upstream configuration, which will handle
19288 requests with two servers.
19293 (nginx-configuration
19295 (list (nginx-server-configuration
19296 (server-name '("www.example.com"))
19297 (root "/srv/http/www.example.com")
19300 (nginx-location-configuration
19302 (body '("proxy_pass http://server-proxy;"))))))))
19304 (list (nginx-upstream-configuration
19305 (name "server-proxy")
19306 (servers (list "server1.example.com"
19307 "server2.example.com")))))))
19310 @item @code{file} (default: @code{#f})
19311 If a configuration @var{file} is provided, this will be used, rather than
19312 generating a configuration file from the provided @code{log-directory},
19313 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
19314 proper operation, these arguments should match what is in @var{file} to ensure
19315 that the directories are created when the service is activated.
19317 This can be useful if you have an existing configuration file, or it's
19318 not possible to do what is required through the other parts of the
19319 nginx-configuration record.
19321 @item @code{server-names-hash-bucket-size} (default: @code{#f})
19322 Bucket size for the server names hash tables, defaults to @code{#f} to
19323 use the size of the processors cache line.
19325 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
19326 Maximum bucket size for the server names hash tables.
19328 @item @code{extra-content} (default: @code{""})
19329 Extra content for the @code{http} block. Should be string or a string
19330 valued G-expression.
19335 @deftp {Data Type} nginx-server-configuration
19336 Data type representing the configuration of an nginx server block.
19337 This type has the following parameters:
19340 @item @code{listen} (default: @code{'("80" "443 ssl")})
19341 Each @code{listen} directive sets the address and port for IP, or the
19342 path for a UNIX-domain socket on which the server will accept requests.
19343 Both address and port, or only address or only port can be specified.
19344 An address may also be a hostname, for example:
19347 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
19350 @item @code{server-name} (default: @code{(list 'default)})
19351 A list of server names this server represents. @code{'default} represents the
19352 default server for connections matching no other server.
19354 @item @code{root} (default: @code{"/srv/http"})
19355 Root of the website nginx will serve.
19357 @item @code{locations} (default: @code{'()})
19358 A list of @dfn{nginx-location-configuration} or
19359 @dfn{nginx-named-location-configuration} records to use within this
19362 @item @code{index} (default: @code{(list "index.html")})
19363 Index files to look for when clients ask for a directory. If it cannot be found,
19364 Nginx will send the list of files in the directory.
19366 @item @code{try-files} (default: @code{'()})
19367 A list of files whose existence is checked in the specified order.
19368 @code{nginx} will use the first file it finds to process the request.
19370 @item @code{ssl-certificate} (default: @code{#f})
19371 Where to find the certificate for secure connections. Set it to @code{#f} if
19372 you don't have a certificate or you don't want to use HTTPS.
19374 @item @code{ssl-certificate-key} (default: @code{#f})
19375 Where to find the private key for secure connections. Set it to @code{#f} if
19376 you don't have a key or you don't want to use HTTPS.
19378 @item @code{server-tokens?} (default: @code{#f})
19379 Whether the server should add its configuration to response.
19381 @item @code{raw-content} (default: @code{'()})
19382 A list of raw lines added to the server block.
19387 @deftp {Data Type} nginx-upstream-configuration
19388 Data type representing the configuration of an nginx @code{upstream}
19389 block. This type has the following parameters:
19393 Name for this group of servers.
19395 @item @code{servers}
19396 Specify the addresses of the servers in the group. The address can be
19397 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
19398 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
19399 prefix @samp{unix:}. For addresses using an IP address or domain name,
19400 the default port is 80, and a different port can be specified
19406 @deftp {Data Type} nginx-location-configuration
19407 Data type representing the configuration of an nginx @code{location}
19408 block. This type has the following parameters:
19412 URI which this location block matches.
19414 @anchor{nginx-location-configuration body}
19416 Body of the location block, specified as a list of strings. This can contain
19418 configuration directives. For example, to pass requests to a upstream
19419 server group defined using an @code{nginx-upstream-configuration} block,
19420 the following directive would be specified in the body @samp{(list "proxy_pass
19421 http://upstream-name;")}.
19426 @deftp {Data Type} nginx-named-location-configuration
19427 Data type representing the configuration of an nginx named location
19428 block. Named location blocks are used for request redirection, and not
19429 used for regular request processing. This type has the following
19434 Name to identify this location block.
19437 @xref{nginx-location-configuration body}, as the body for named location
19438 blocks can be used in a similar way to the
19439 @code{nginx-location-configuration body}. One restriction is that the
19440 body of a named location block cannot contain location blocks.
19445 @subsubheading Varnish Cache
19447 Varnish is a fast cache server that sits in between web applications
19448 and end users. It proxies requests from clients and caches the
19449 accessed URLs such that multiple requests for the same resource only
19450 creates one request to the back-end.
19452 @defvr {Scheme Variable} varnish-service-type
19453 Service type for the Varnish daemon.
19456 @deftp {Data Type} varnish-configuration
19457 Data type representing the @code{varnish} service configuration.
19458 This type has the following parameters:
19461 @item @code{package} (default: @code{varnish})
19462 The Varnish package to use.
19464 @item @code{name} (default: @code{"default"})
19465 A name for this Varnish instance. Varnish will create a directory in
19466 @file{/var/varnish/} with this name and keep temporary files there. If
19467 the name starts with a forward slash, it is interpreted as an absolute
19470 Pass the @code{-n} argument to other Varnish programs to connect to the
19471 named instance, e.g.@: @command{varnishncsa -n default}.
19473 @item @code{backend} (default: @code{"localhost:8080"})
19474 The backend to use. This option has no effect if @code{vcl} is set.
19476 @item @code{vcl} (default: #f)
19477 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
19478 is @code{#f}, Varnish will proxy @code{backend} using the default
19479 configuration. Otherwise this must be a file-like object with valid
19482 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
19483 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
19484 can do something along these lines:
19487 (define %gnu-mirror
19491 backend gnu @{ .host = "www.gnu.org"; @}"))
19495 (services (cons (service varnish-service-type
19496 (varnish-configuration
19498 (vcl %gnu-mirror)))
19502 The configuration of an already running Varnish instance can be inspected
19503 and changed using the @command{varnishadm} program.
19505 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19506 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19507 comprehensive documentation on Varnish and its configuration language.
19509 @item @code{listen} (default: @code{'("localhost:80")})
19510 List of addresses Varnish will listen on.
19512 @item @code{storage} (default: @code{'("malloc,128m")})
19513 List of storage backends that will be available in VCL.
19515 @item @code{parameters} (default: @code{'()})
19516 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19518 @item @code{extra-options} (default: @code{'()})
19519 Additional arguments to pass to the @command{varnishd} process.
19524 @subsubheading Patchwork
19526 Patchwork is a patch tracking system. It can collect patches sent to a
19527 mailing list, and display them in a web interface.
19529 @defvr {Scheme Variable} patchwork-service-type
19530 Service type for Patchwork.
19533 The following example is an example of a minimal service for Patchwork, for
19534 the @code{patchwork.example.com} domain.
19537 (service patchwork-service-type
19538 (patchwork-configuration
19539 (domain "patchwork.example.com")
19541 (patchwork-settings-module
19542 (allowed-hosts (list domain))
19543 (default-from-email "patchwork@@patchwork.example.com")))
19544 (getmail-retriever-config
19545 (getmail-retriever-configuration
19546 (type "SimpleIMAPSSLRetriever")
19547 (server "imap.example.com")
19549 (username "patchwork")
19551 (list (file-append coreutils "/bin/cat")
19552 "/etc/getmail-patchwork-imap-password"))
19554 '((mailboxes . ("Patches"))))))))
19558 There are three records for configuring the Patchwork service. The
19559 @code{<patchwork-configuration>} relates to the configuration for Patchwork
19560 within the HTTPD service.
19562 The @code{settings-module} field within the @code{<patchwork-configuration>}
19563 record can be populated with the @code{<patchwork-settings-module>} record,
19564 which describes a settings module that is generated within the Guix store.
19566 For the @code{database-configuration} field within the
19567 @code{<patchwork-settings-module>}, the
19568 @code{<patchwork-database-configuration>} must be used.
19570 @deftp {Data Type} patchwork-configuration
19571 Data type representing the Patchwork service configuration. This type has the
19572 following parameters:
19575 @item @code{patchwork} (default: @code{patchwork})
19576 The Patchwork package to use.
19578 @item @code{domain}
19579 The domain to use for Patchwork, this is used in the HTTPD service virtual
19582 @item @code{settings-module}
19583 The settings module to use for Patchwork. As a Django application, Patchwork
19584 is configured with a Python module containing the settings. This can either be
19585 an instance of the @code{<patchwork-settings-module>} record, any other record
19586 that represents the settings in the store, or a directory outside of the
19589 @item @code{static-path} (default: @code{"/static/"})
19590 The path under which the HTTPD service should serve the static files.
19592 @item @code{getmail-retriever-config}
19593 The getmail-retriever-configuration record value to use with
19594 Patchwork. Getmail will be configured with this value, the messages will be
19595 delivered to Patchwork.
19600 @deftp {Data Type} patchwork-settings-module
19601 Data type representing a settings module for Patchwork. Some of these
19602 settings relate directly to Patchwork, but others relate to Django, the web
19603 framework used by Patchwork, or the Django Rest Framework library. This type
19604 has the following parameters:
19607 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
19608 The database connection settings used for Patchwork. See the
19609 @code{<patchwork-database-configuration>} record type for more information.
19611 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
19612 Patchwork, as a Django web application uses a secret key for cryptographically
19613 signing values. This file should contain a unique unpredictable value.
19615 If this file does not exist, it will be created and populated with a random
19616 value by the patchwork-setup shepherd service.
19618 This setting relates to Django.
19620 @item @code{allowed-hosts}
19621 A list of valid hosts for this Patchwork service. This should at least include
19622 the domain specified in the @code{<patchwork-configuration>} record.
19624 This is a Django setting.
19626 @item @code{default-from-email}
19627 The email address from which Patchwork should send email by default.
19629 This is a Patchwork setting.
19631 @item @code{static-url} (default: @code{#f})
19632 The URL to use when serving static assets. It can be part of a URL, or a full
19633 URL, but must end in a @code{/}.
19635 If the default value is used, the @code{static-path} value from the
19636 @code{<patchwork-configuration>} record will be used.
19638 This is a Django setting.
19640 @item @code{admins} (default: @code{'()})
19641 Email addresses to send the details of errors that occur. Each value should
19642 be a list containing two elements, the name and then the email address.
19644 This is a Django setting.
19646 @item @code{debug?} (default: @code{#f})
19647 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
19648 messages will be shown.
19650 This is a Django setting.
19652 @item @code{enable-rest-api?} (default: @code{#t})
19653 Whether to enable the Patchwork REST API.
19655 This is a Patchwork setting.
19657 @item @code{enable-xmlrpc?} (default: @code{#t})
19658 Whether to enable the XML RPC API.
19660 This is a Patchwork setting.
19662 @item @code{force-https-links?} (default: @code{#t})
19663 Whether to use HTTPS links on Patchwork pages.
19665 This is a Patchwork setting.
19667 @item @code{extra-settings} (default: @code{""})
19668 Extra code to place at the end of the Patchwork settings module.
19673 @deftp {Data Type} patchwork-database-configuration
19674 Data type representing the database configuration for Patchwork.
19677 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
19678 The database engine to use.
19680 @item @code{name} (default: @code{"patchwork"})
19681 The name of the database to use.
19683 @item @code{user} (default: @code{"httpd"})
19684 The user to connect to the database as.
19686 @item @code{password} (default: @code{""})
19687 The password to use when connecting to the database.
19689 @item @code{host} (default: @code{""})
19690 The host to make the database connection to.
19692 @item @code{port} (default: @code{""})
19693 The port on which to connect to the database.
19698 @subsubheading FastCGI
19701 FastCGI is an interface between the front-end and the back-end of a web
19702 service. It is a somewhat legacy facility; new web services should
19703 generally just talk HTTP between the front-end and the back-end.
19704 However there are a number of back-end services such as PHP or the
19705 optimized HTTP Git repository access that use FastCGI, so we have
19706 support for it in Guix.
19708 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19709 dispatch some subset of its requests to the fastcgi backend, which
19710 listens on a local TCP or UNIX socket. There is an intermediary
19711 @code{fcgiwrap} program that sits between the actual backend process and
19712 the web server. The front-end indicates which backend program to run,
19713 passing that information to the @code{fcgiwrap} process.
19715 @defvr {Scheme Variable} fcgiwrap-service-type
19716 A service type for the @code{fcgiwrap} FastCGI proxy.
19719 @deftp {Data Type} fcgiwrap-configuration
19720 Data type representing the configuration of the @code{fcgiwrap} service.
19721 This type has the following parameters:
19723 @item @code{package} (default: @code{fcgiwrap})
19724 The fcgiwrap package to use.
19726 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19727 The socket on which the @code{fcgiwrap} process should listen, as a
19728 string. Valid @var{socket} values include
19729 @code{unix:@var{/path/to/unix/socket}},
19730 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19731 @code{tcp6:[@var{ipv6_addr}]:port}.
19733 @item @code{user} (default: @code{fcgiwrap})
19734 @itemx @code{group} (default: @code{fcgiwrap})
19735 The user and group names, as strings, under which to run the
19736 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19737 the user asks for the specific user or group names @code{fcgiwrap} that
19738 the corresponding user and/or group is present on the system.
19740 It is possible to configure a FastCGI-backed web service to pass HTTP
19741 authentication information from the front-end to the back-end, and to
19742 allow @code{fcgiwrap} to run the back-end process as a corresponding
19743 local user. To enable this capability on the back-end., run
19744 @code{fcgiwrap} as the @code{root} user and group. Note that this
19745 capability also has to be configured on the front-end as well.
19750 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19751 with some additional features useful for sites of any size.
19753 These features include:
19755 @item Adaptive process spawning
19756 @item Basic statistics (similar to Apache's mod_status)
19757 @item Advanced process management with graceful stop/start
19758 @item Ability to start workers with different uid/gid/chroot/environment
19759 and different php.ini (replaces safe_mode)
19760 @item Stdout & stderr logging
19761 @item Emergency restart in case of accidental opcode cache destruction
19762 @item Accelerated upload support
19763 @item Support for a "slowlog"
19764 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19765 a special function to finish request & flush all data while continuing to do
19766 something time-consuming (video converting, stats processing, etc.)
19768 ...@: and much more.
19770 @defvr {Scheme Variable} php-fpm-service-type
19771 A Service type for @code{php-fpm}.
19774 @deftp {Data Type} php-fpm-configuration
19775 Data Type for php-fpm service configuration.
19777 @item @code{php} (default: @code{php})
19778 The php package to use.
19779 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19780 The address on which to accept FastCGI requests. Valid syntaxes are:
19782 @item @code{"ip.add.re.ss:port"}
19783 Listen on a TCP socket to a specific address on a specific port.
19784 @item @code{"port"}
19785 Listen on a TCP socket to all addresses on a specific port.
19786 @item @code{"/path/to/unix/socket"}
19787 Listen on a unix socket.
19790 @item @code{user} (default: @code{php-fpm})
19791 User who will own the php worker processes.
19792 @item @code{group} (default: @code{php-fpm})
19793 Group of the worker processes.
19794 @item @code{socket-user} (default: @code{php-fpm})
19795 User who can speak to the php-fpm socket.
19796 @item @code{socket-group} (default: @code{php-fpm})
19797 Group that can speak to the php-fpm socket.
19798 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19799 The process id of the php-fpm process is written to this file
19800 once the service has started.
19801 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19802 Log for the php-fpm master process.
19803 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19804 Detailed settings for the php-fpm process manager.
19807 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19808 @item @code{<php-fpm-static-process-manager-configuration>}
19809 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19811 @item @code{display-errors} (default @code{#f})
19812 Determines whether php errors and warning should be sent to clients
19813 and displayed in their browsers.
19814 This is useful for local php development, but a security risk for public sites,
19815 as error messages can reveal passwords and personal data.
19816 @item @code{timezone} (default @code{#f})
19817 Specifies @code{php_admin_value[date.timezone]} parameter.
19818 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19819 This file will log the @code{stderr} outputs of php worker processes.
19820 Can be set to @code{#f} to disable logging.
19821 @item @code{file} (default @code{#f})
19822 An optional override of the whole configuration.
19823 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19827 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19828 Data Type for the @code{dynamic} php-fpm process manager. With the
19829 @code{dynamic} process manager, spare worker processes are kept around
19830 based on it's configured limits.
19832 @item @code{max-children} (default: @code{5})
19833 Maximum of worker processes.
19834 @item @code{start-servers} (default: @code{2})
19835 How many worker processes should be started on start-up.
19836 @item @code{min-spare-servers} (default: @code{1})
19837 How many spare worker processes should be kept around at minimum.
19838 @item @code{max-spare-servers} (default: @code{3})
19839 How many spare worker processes should be kept around at maximum.
19843 @deftp {Data type} php-fpm-static-process-manager-configuration
19844 Data Type for the @code{static} php-fpm process manager. With the
19845 @code{static} process manager, an unchanging number of worker processes
19848 @item @code{max-children} (default: @code{5})
19849 Maximum of worker processes.
19853 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19854 Data Type for the @code{on-demand} php-fpm process manager. With the
19855 @code{on-demand} process manager, worker processes are only created as
19858 @item @code{max-children} (default: @code{5})
19859 Maximum of worker processes.
19860 @item @code{process-idle-timeout} (default: @code{10})
19861 The time in seconds after which a process with no requests is killed.
19866 @deffn {Scheme Procedure} nginx-php-fpm-location @
19867 [#:nginx-package nginx] @
19868 [socket (string-append "/var/run/php" @
19869 (version-major (package-version php)) @
19871 A helper function to quickly add php to an @code{nginx-server-configuration}.
19874 A simple services setup for nginx with php can look like this:
19876 (services (cons* (service dhcp-client-service-type)
19877 (service php-fpm-service-type)
19878 (service nginx-service-type
19879 (nginx-server-configuration
19880 (server-name '("example.com"))
19881 (root "/srv/http/")
19883 (list (nginx-php-location)))
19885 (ssl-certificate #f)
19886 (ssl-certificate-key #f)))
19890 @cindex cat-avatar-generator
19891 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19892 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19893 the hash of a user's email address.
19895 @deffn {Scheme Procedure} cat-avatar-generator-service @
19896 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19897 [#:package cat-avatar-generator] @
19898 [#:configuration (nginx-server-configuration)]
19899 Returns an nginx-server-configuration that inherits @code{configuration}. It
19900 extends the nginx configuration to add a server block that serves @code{package},
19901 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19902 be able to use @code{cache-dir} as its cache directory.
19905 A simple setup for cat-avatar-generator can look like this:
19907 (services (cons* (cat-avatar-generator-service
19909 (nginx-server-configuration
19910 (server-name '("example.com"))))
19915 @subsubheading Hpcguix-web
19917 @cindex hpcguix-web
19918 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
19919 program is a customizable web interface to browse Guix packages,
19920 initially designed for users of high-performance computing (HPC)
19923 @defvr {Scheme Variable} hpcguix-web-service-type
19924 The service type for @code{hpcguix-web}.
19927 @deftp {Data Type} hpcguix-web-configuration
19928 Data type for the hpcguix-web service configuration.
19932 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19933 configuration. The main items available in this spec are:
19936 @item @code{title-prefix} (default: @code{"hpcguix | "})
19937 The page title prefix.
19939 @item @code{guix-command} (default: @code{"guix"})
19940 The @command{guix} command.
19942 @item @code{package-filter-proc} (default: @code{(const #t)})
19943 A procedure specifying how to filter packages that are displayed.
19945 @item @code{package-page-extension-proc} (default: @code{(const '())})
19946 Extension package for @code{hpcguix-web}.
19948 @item @code{menu} (default: @code{'()})
19949 Additional entry in page @code{menu}.
19951 @item @code{channels} (default: @code{%default-channels})
19952 List of channels from which the package list is built (@pxref{Channels}).
19954 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19955 The expiration time, in seconds, after which the package list is rebuilt from
19956 the latest instances of the given channels.
19959 See the hpcguix-web repository for a
19960 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19963 @item @code{package} (default: @code{hpcguix-web})
19964 The hpcguix-web package to use.
19968 A typical hpcguix-web service declaration looks like this:
19971 (service hpcguix-web-service-type
19972 (hpcguix-web-configuration
19974 #~(define site-config
19975 (hpcweb-configuration
19976 (title-prefix "Guix-HPC - ")
19977 (menu '(("/about" "ABOUT"))))))))
19981 The hpcguix-web service periodically updates the package list it publishes by
19982 pulling channels from Git. To that end, it needs to access X.509 certificates
19983 so that it can authenticate Git servers when communicating over HTTPS, and it
19984 assumes that @file{/etc/ssl/certs} contains those certificates.
19986 Thus, make sure to add @code{nss-certs} or another certificate package to the
19987 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19988 more information on X.509 certificates.
19991 @node Certificate Services
19992 @subsection Certificate Services
19995 @cindex HTTP, HTTPS
19996 @cindex Let's Encrypt
19997 @cindex TLS certificates
19998 The @code{(gnu services certbot)} module provides a service to
19999 automatically obtain a valid TLS certificate from the Let's Encrypt
20000 certificate authority. These certificates can then be used to serve
20001 content securely over HTTPS or other TLS-based protocols, with the
20002 knowledge that the client will be able to verify the server's
20005 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20006 @code{certbot} tool to automate the certification process. This tool
20007 first securely generates a key on the server. It then makes a request
20008 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20009 checks that the request originates from the host in question by using a
20010 challenge-response protocol, requiring the server to provide its
20011 response over HTTP. If that protocol completes successfully, the CA
20012 signs the key, resulting in a certificate. That certificate is valid
20013 for a limited period of time, and therefore to continue to provide TLS
20014 services, the server needs to periodically ask the CA to renew its
20017 The certbot service automates this process: the initial key
20018 generation, the initial certification request to the Let's Encrypt
20019 service, the web server challenge/response integration, writing the
20020 certificate to disk, the automated periodic renewals, and the deployment
20021 tasks associated with the renewal (e.g.@: reloading services, copying keys
20022 with different permissions).
20024 Certbot is run twice a day, at a random minute within the hour. It
20025 won't do anything until your certificates are due for renewal or
20026 revoked, but running it regularly would give your service a chance of
20027 staying online in case a Let's Encrypt-initiated revocation happened for
20030 By using this service, you agree to the ACME Subscriber Agreement, which
20031 can be found there:
20032 @url{https://acme-v01.api.letsencrypt.org/directory}.
20034 @defvr {Scheme Variable} certbot-service-type
20035 A service type for the @code{certbot} Let's Encrypt client. Its value
20036 must be a @code{certbot-configuration} record as in this example:
20039 (define %nginx-deploy-hook
20041 "nginx-deploy-hook"
20042 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20043 (kill pid SIGHUP))))
20045 (service certbot-service-type
20046 (certbot-configuration
20047 (email "foo@@example.net")
20050 (certificate-configuration
20051 (domains '("example.net" "www.example.net"))
20052 (deploy-hook %nginx-deploy-hook))
20053 (certificate-configuration
20054 (domains '("bar.example.net")))))))
20057 See below for details about @code{certbot-configuration}.
20060 @deftp {Data Type} certbot-configuration
20061 Data type representing the configuration of the @code{certbot} service.
20062 This type has the following parameters:
20065 @item @code{package} (default: @code{certbot})
20066 The certbot package to use.
20068 @item @code{webroot} (default: @code{/var/www})
20069 The directory from which to serve the Let's Encrypt challenge/response
20072 @item @code{certificates} (default: @code{()})
20073 A list of @code{certificates-configuration}s for which to generate
20074 certificates and request signatures. Each certificate has a @code{name}
20075 and several @code{domains}.
20078 Mandatory email used for registration, recovery contact, and important
20079 account notifications.
20081 @item @code{rsa-key-size} (default: @code{2048})
20082 Size of the RSA key.
20084 @item @code{default-location} (default: @i{see below})
20085 The default @code{nginx-location-configuration}. Because @code{certbot}
20086 needs to be able to serve challenges and responses, it needs to be able
20087 to run a web server. It does so by extending the @code{nginx} web
20088 service with an @code{nginx-server-configuration} listening on the
20089 @var{domains} on port 80, and which has a
20090 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20091 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20092 these nginx configuration data types.
20094 Requests to other URL paths will be matched by the
20095 @code{default-location}, which if present is added to all
20096 @code{nginx-server-configuration}s.
20098 By default, the @code{default-location} will issue a redirect from
20099 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20100 you to define what to serve on your site via @code{https}.
20102 Pass @code{#f} to not issue a default location.
20106 @deftp {Data Type} certificate-configuration
20107 Data type representing the configuration of a certificate.
20108 This type has the following parameters:
20111 @item @code{name} (default: @i{see below})
20112 This name is used by Certbot for housekeeping and in file paths; it
20113 doesn't affect the content of the certificate itself. To see
20114 certificate names, run @code{certbot certificates}.
20116 Its default is the first provided domain.
20118 @item @code{domains} (default: @code{()})
20119 The first domain provided will be the subject CN of the certificate, and
20120 all domains will be Subject Alternative Names on the certificate.
20122 @item @code{challenge} (default: @code{#f})
20123 The challenge type that has to be run by certbot. If @code{#f} is specified,
20124 default to the HTTP challenge. If a value is specified, defaults to the
20125 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20126 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
20128 @item @code{authentication-hook} (default: @code{#f})
20129 Command to be run in a shell once for each certificate challenge to be
20130 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20131 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20132 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20133 file name of the resource requested when performing an HTTP-01 challenge.
20135 @item @code{cleanup-hook} (default: @code{#f})
20136 Command to be run in a shell once for each certificate challenge that
20137 have been answered by the @code{auth-hook}. For this command, the shell
20138 variables available in the @code{auth-hook} script are still available, and
20139 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20140 of the @code{auth-hook} script.
20142 @item @code{deploy-hook} (default: @code{#f})
20143 Command to be run in a shell once for each successfully issued
20144 certificate. For this command, the shell variable
20145 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20146 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20147 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20148 contain a space-delimited list of renewed certificate domains (for
20149 example, @samp{"example.com www.example.com"}.
20154 For each @code{certificate-configuration}, the certificate is saved to
20155 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20156 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20158 @subsection DNS Services
20159 @cindex DNS (domain name system)
20160 @cindex domain name system (DNS)
20162 The @code{(gnu services dns)} module provides services related to the
20163 @dfn{domain name system} (DNS). It provides a server service for hosting
20164 an @emph{authoritative} DNS server for multiple zones, slave or master.
20165 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20166 caching and forwarding DNS server for the LAN, which uses
20167 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20169 @subsubheading Knot Service
20171 An example configuration of an authoritative server for two zones, one master
20175 (define-zone-entries example.org.zone
20176 ;; Name TTL Class Type Data
20177 ("@@" "" "IN" "A" "127.0.0.1")
20178 ("@@" "" "IN" "NS" "ns")
20179 ("ns" "" "IN" "A" "127.0.0.1"))
20181 (define master-zone
20182 (knot-zone-configuration
20183 (domain "example.org")
20185 (origin "example.org")
20186 (entries example.org.zone)))))
20189 (knot-zone-configuration
20190 (domain "plop.org")
20191 (dnssec-policy "default")
20192 (master (list "plop-master"))))
20194 (define plop-master
20195 (knot-remote-configuration
20197 (address (list "208.76.58.171"))))
20201 (services (cons* (service knot-service-type
20202 (knot-configuration
20203 (remotes (list plop-master))
20204 (zones (list master-zone slave-zone))))
20209 @deffn {Scheme Variable} knot-service-type
20210 This is the type for the Knot DNS server.
20212 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20213 zones, that is to say domain names you would buy from a registrar. This server
20214 is not a resolver, meaning that it can only resolve names for which it is
20215 authoritative. This server can be configured to serve zones as a master server
20216 or a slave server as a per-zone basis. Slave zones will get their data from
20217 masters, and will serve it as an authoritative server. From the point of view
20218 of a resolver, there is no difference between master and slave.
20220 The following data types are used to configure the Knot DNS server:
20223 @deftp {Data Type} knot-key-configuration
20224 Data type representing a key.
20225 This type has the following parameters:
20228 @item @code{id} (default: @code{""})
20229 An identifier for other configuration fields to refer to this key. IDs must
20230 be unique and must not be empty.
20232 @item @code{algorithm} (default: @code{#f})
20233 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
20234 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
20235 and @code{'hmac-sha512}.
20237 @item @code{secret} (default: @code{""})
20238 The secret key itself.
20243 @deftp {Data Type} knot-acl-configuration
20244 Data type representing an Access Control List (ACL) configuration.
20245 This type has the following parameters:
20248 @item @code{id} (default: @code{""})
20249 An identifier for ether configuration fields to refer to this key. IDs must be
20250 unique and must not be empty.
20252 @item @code{address} (default: @code{'()})
20253 An ordered list of IP addresses, network subnets, or network ranges represented
20254 with strings. The query must match one of them. Empty value means that
20255 address match is not required.
20257 @item @code{key} (default: @code{'()})
20258 An ordered list of references to keys represented with strings. The string
20259 must match a key ID defined in a @code{knot-key-configuration}. No key means
20260 that a key is not require to match that ACL.
20262 @item @code{action} (default: @code{'()})
20263 An ordered list of actions that are permitted or forbidden by this ACL. Possible
20264 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
20265 and @code{'update}.
20267 @item @code{deny?} (default: @code{#f})
20268 When true, the ACL defines restrictions. Listed actions are forbidden. When
20269 false, listed actions are allowed.
20274 @deftp {Data Type} zone-entry
20275 Data type represnting a record entry in a zone file.
20276 This type has the following parameters:
20279 @item @code{name} (default: @code{"@@"})
20280 The name of the record. @code{"@@"} refers to the origin of the zone. Names
20281 are relative to the origin of the zone. For example, in the @code{example.org}
20282 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
20283 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
20284 refers to @code{ns.example.org}.
20286 @item @code{ttl} (default: @code{""})
20287 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
20289 @item @code{class} (default: @code{"IN"})
20290 The class of the record. Knot currently supports only @code{"IN"} and
20291 partially @code{"CH"}.
20293 @item @code{type} (default: @code{"A"})
20294 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
20295 address), NS (Name Server) and MX (Mail eXchange). Many other types are
20298 @item @code{data} (default: @code{""})
20299 The data contained in the record. For instance an IP address associated with
20300 an A record, or a domain name associated with an NS record. Remember that
20301 domain names are relative to the origin unless they end with a dot.
20306 @deftp {Data Type} zone-file
20307 Data type representing the content of a zone file.
20308 This type has the following parameters:
20311 @item @code{entries} (default: @code{'()})
20312 The list of entries. The SOA record is taken care of, so you don't need to
20313 put it in the list of entries. This list should probably contain an entry
20314 for your primary authoritative DNS server. Other than using a list of entries
20315 directly, you can use @code{define-zone-entries} to define a object containing
20316 the list of entries more easily, that you can later pass to the @code{entries}
20317 field of the @code{zone-file}.
20319 @item @code{origin} (default: @code{""})
20320 The name of your zone. This parameter cannot be empty.
20322 @item @code{ns} (default: @code{"ns"})
20323 The domain of your primary authoritative DNS server. The name is relative to
20324 the origin, unless it ends with a dot. It is mandatory that this primary
20325 DNS server corresponds to an NS record in the zone and that it is associated
20326 to an IP address in the list of entries.
20328 @item @code{mail} (default: @code{"hostmaster"})
20329 An email address people can contact you at, as the owner of the zone. This
20330 is translated as @code{<mail>@@<origin>}.
20332 @item @code{serial} (default: @code{1})
20333 The serial number of the zone. As this is used to keep track of changes by
20334 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
20335 Always increment it when you make a change in your zone.
20337 @item @code{refresh} (default: @code{(* 2 24 3600)})
20338 The frequency at which slaves will do a zone transfer. This value is a number
20339 of seconds. It can be computed by multiplications or with
20340 @code{(string->duration)}.
20342 @item @code{retry} (default: @code{(* 15 60)})
20343 The period after which a slave will retry to contact its master when it fails
20344 to do so a first time.
20346 @item @code{expiry} (default: @code{(* 14 24 3600)})
20347 Default TTL of records. Existing records are considered correct for at most
20348 this amount of time. After this period, resolvers will invalidate their cache
20349 and check again that it still exists.
20351 @item @code{nx} (default: @code{3600})
20352 Default TTL of inexistant records. This delay is usually short because you want
20353 your new domains to reach everyone quickly.
20358 @deftp {Data Type} knot-remote-configuration
20359 Data type representing a remote configuration.
20360 This type has the following parameters:
20363 @item @code{id} (default: @code{""})
20364 An identifier for other configuration fields to refer to this remote. IDs must
20365 be unique and must not be empty.
20367 @item @code{address} (default: @code{'()})
20368 An ordered list of destination IP addresses. Addresses are tried in sequence.
20369 An optional port can be given with the @@ separator. For instance:
20370 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
20372 @item @code{via} (default: @code{'()})
20373 An ordered list of source IP addresses. An empty list will have Knot choose
20374 an appropriate source IP. An optional port can be given with the @@ separator.
20375 The default is to choose at random.
20377 @item @code{key} (default: @code{#f})
20378 A reference to a key, that is a string containing the identifier of a key
20379 defined in a @code{knot-key-configuration} field.
20384 @deftp {Data Type} knot-keystore-configuration
20385 Data type representing a keystore to hold dnssec keys.
20386 This type has the following parameters:
20389 @item @code{id} (default: @code{""})
20390 The id of the keystore. It must not be empty.
20392 @item @code{backend} (default: @code{'pem})
20393 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
20395 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
20396 The configuration string of the backend. An example for the PKCS#11 is:
20397 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
20398 For the pem backend, the string reprensents a path in the file system.
20403 @deftp {Data Type} knot-policy-configuration
20404 Data type representing a dnssec policy. Knot DNS is able to automatically
20405 sign your zones. It can either generate and manage your keys automatically or
20406 use keys that you generate.
20408 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
20409 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
20410 zone. In order to be trusted, the KSK needs to be present in the parent zone
20411 (usually a top-level domain). If your registrar supports dnssec, you will
20412 have to send them your KSK's hash so they can add a DS record in their zone.
20413 This is not automated and need to be done each time you change your KSK.
20415 The policy also defines the lifetime of keys. Usually, ZSK can be changed
20416 easily and use weaker cryptographic functions (they use lower parameters) in
20417 order to sign records quickly, so they are changed often. The KSK however
20418 requires manual interaction with the registrar, so they are changed less often
20419 and use stronger parameters because they sign only one record.
20421 This type has the following parameters:
20424 @item @code{id} (default: @code{""})
20425 The id of the policy. It must not be empty.
20427 @item @code{keystore} (default: @code{"default"})
20428 A reference to a keystore, that is a string containing the identifier of a
20429 keystore defined in a @code{knot-keystore-configuration} field. The
20430 @code{"default"} identifier means the default keystore (a kasp database that
20431 was setup by this service).
20433 @item @code{manual?} (default: @code{#f})
20434 Whether the key management is manual or automatic.
20436 @item @code{single-type-signing?} (default: @code{#f})
20437 When @code{#t}, use the Single-Type Signing Scheme.
20439 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
20440 An algorithm of signing keys and issued signatures.
20442 @item @code{ksk-size} (default: @code{256})
20443 The length of the KSK. Note that this value is correct for the default
20444 algorithm, but would be unsecure for other algorithms.
20446 @item @code{zsk-size} (default: @code{256})
20447 The length of the ZSK. Note that this value is correct for the default
20448 algorithm, but would be unsecure for other algorithms.
20450 @item @code{dnskey-ttl} (default: @code{'default})
20451 The TTL value for DNSKEY records added into zone apex. The special
20452 @code{'default} value means same as the zone SOA TTL.
20454 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
20455 The period between ZSK publication and the next rollover initiation.
20457 @item @code{propagation-delay} (default: @code{(* 24 3600)})
20458 An extra delay added for each key rollover step. This value should be high
20459 enough to cover propagation of data from the master server to all slaves.
20461 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
20462 A validity period of newly issued signatures.
20464 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
20465 A period how long before a signature expiration the signature will be refreshed.
20467 @item @code{nsec3?} (default: @code{#f})
20468 When @code{#t}, NSEC3 will be used instead of NSEC.
20470 @item @code{nsec3-iterations} (default: @code{5})
20471 The number of additional times the hashing is performed.
20473 @item @code{nsec3-salt-length} (default: @code{8})
20474 The length of a salt field in octets, which is appended to the original owner
20475 name before hashing.
20477 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
20478 The validity period of newly issued salt field.
20483 @deftp {Data Type} knot-zone-configuration
20484 Data type representing a zone served by Knot.
20485 This type has the following parameters:
20488 @item @code{domain} (default: @code{""})
20489 The domain served by this configuration. It must not be empty.
20491 @item @code{file} (default: @code{""})
20492 The file where this zone is saved. This parameter is ignored by master zones.
20493 Empty means default location that depends on the domain name.
20495 @item @code{zone} (default: @code{(zone-file)})
20496 The content of the zone file. This parameter is ignored by slave zones. It
20497 must contain a zone-file record.
20499 @item @code{master} (default: @code{'()})
20500 A list of master remotes. When empty, this zone is a master. When set, this
20501 zone is a slave. This is a list of remotes identifiers.
20503 @item @code{ddns-master} (default: @code{#f})
20504 The main master. When empty, it defaults to the first master in the list of
20507 @item @code{notify} (default: @code{'()})
20508 A list of slave remote identifiers.
20510 @item @code{acl} (default: @code{'()})
20511 A list of acl identifiers.
20513 @item @code{semantic-checks?} (default: @code{#f})
20514 When set, this adds more semantic checks to the zone.
20516 @item @code{disable-any?} (default: @code{#f})
20517 When set, this forbids queries of the ANY type.
20519 @item @code{zonefile-sync} (default: @code{0})
20520 The delay between a modification in memory and on disk. 0 means immediate
20523 @item @code{zonefile-load} (default: @code{#f})
20524 The way the zone file contents are applied during zone load. Possible values
20528 @item @code{#f} for using the default value from Knot,
20529 @item @code{'none} for not using the zone file at all,
20530 @item @code{'difference} for computing the difference between already available
20531 contents and zone contents and applying it to the current zone contents,
20532 @item @code{'difference-no-serial} for the same as @code{'difference}, but
20533 ignoring the SOA serial in the zone file, while the server takes care of it
20535 @item @code{'whole} for loading zone contents from the zone file.
20538 @item @code{journal-content} (default: @code{#f})
20539 The way the journal is used to store zone and its changes. Possible values
20540 are @code{'none} to not use it at all, @code{'changes} to store changes and
20541 @code{'all} to store contents. @code{#f} does not set this option, so the
20542 default value from Knot is used.
20544 @item @code{max-journal-usage} (default: @code{#f})
20545 The maximum size for the journal on disk. @code{#f} does not set this option,
20546 so the default value from Knot is used.
20548 @item @code{max-journal-depth} (default: @code{#f})
20549 The maximum size of the history. @code{#f} does not set this option, so the
20550 default value from Knot is used.
20552 @item @code{max-zone-size} (default: @code{#f})
20553 The maximum size of the zone file. This limit is enforced for incoming
20554 transfer and updates. @code{#f} does not set this option, so the default
20555 value from Knot is used.
20557 @item @code{dnssec-policy} (default: @code{#f})
20558 A reference to a @code{knot-policy-configuration} record, or the special
20559 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
20562 @item @code{serial-policy} (default: @code{'increment})
20563 A policy between @code{'increment} and @code{'unixtime}.
20568 @deftp {Data Type} knot-configuration
20569 Data type representing the Knot configuration.
20570 This type has the following parameters:
20573 @item @code{knot} (default: @code{knot})
20576 @item @code{run-directory} (default: @code{"/var/run/knot"})
20577 The run directory. This directory will be used for pid file and sockets.
20579 @item @code{includes} (default: @code{'()})
20580 A list of strings or file-like objects denoting other files that must be
20581 included at the top of the configuration file.
20583 @cindex secrets, Knot service
20584 This can be used to manage secrets out-of-band. For example, secret
20585 keys may be stored in an out-of-band file not managed by Guix, and
20586 thus not visible in @file{/gnu/store}---e.g., you could store secret
20587 key configuration in @file{/etc/knot/secrets.conf} and add this file
20588 to the @code{includes} list.
20590 It can also be used to add configuration not supported by this interface.
20592 @item @code{listen-v4} (default: @code{"0.0.0.0"})
20593 An ip address on which to listen.
20595 @item @code{listen-v6} (default: @code{"::"})
20596 An ip address on which to listen.
20598 @item @code{listen-port} (default: @code{53})
20599 A port on which to listen.
20601 @item @code{keys} (default: @code{'()})
20602 The list of knot-key-configuration used by this configuration.
20604 @item @code{acls} (default: @code{'()})
20605 The list of knot-acl-configuration used by this configuration.
20607 @item @code{remotes} (default: @code{'()})
20608 The list of knot-remote-configuration used by this configuration.
20610 @item @code{zones} (default: @code{'()})
20611 The list of knot-zone-configuration used by this configuration.
20616 @subsubheading Dnsmasq Service
20618 @deffn {Scheme Variable} dnsmasq-service-type
20619 This is the type of the dnsmasq service, whose value should be an
20620 @code{dnsmasq-configuration} object as in this example:
20623 (service dnsmasq-service-type
20624 (dnsmasq-configuration
20626 (servers '("192.168.1.1"))))
20630 @deftp {Data Type} dnsmasq-configuration
20631 Data type representing the configuration of dnsmasq.
20634 @item @code{package} (default: @var{dnsmasq})
20635 Package object of the dnsmasq server.
20637 @item @code{no-hosts?} (default: @code{#f})
20638 When true, don't read the hostnames in /etc/hosts.
20640 @item @code{port} (default: @code{53})
20641 The port to listen on. Setting this to zero completely disables DNS
20642 responses, leaving only DHCP and/or TFTP functions.
20644 @item @code{local-service?} (default: @code{#t})
20645 Accept DNS queries only from hosts whose address is on a local subnet,
20646 ie a subnet for which an interface exists on the server.
20648 @item @code{listen-addresses} (default: @code{'()})
20649 Listen on the given IP addresses.
20651 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
20652 The file to read the IP address of the upstream nameservers from.
20654 @item @code{no-resolv?} (default: @code{#f})
20655 When true, don't read @var{resolv-file}.
20657 @item @code{servers} (default: @code{'()})
20658 Specify IP address of upstream servers directly.
20660 @item @code{cache-size} (default: @code{150})
20661 Set the size of dnsmasq's cache. Setting the cache size to zero
20664 @item @code{negative-cache?} (default: @code{#t})
20665 When false, disable negative caching.
20670 @subsubheading ddclient Service
20673 The ddclient service described below runs the ddclient daemon, which takes
20674 care of automatically updating DNS entries for service providers such as
20675 @uref{https://dyn.com/dns/, Dyn}.
20677 The following example show instantiates the service with its default
20681 (service ddclient-service-type)
20684 Note that ddclient needs to access credentials that are stored in a
20685 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20686 @code{secret-file} below.) You are expected to create this file manually, in
20687 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20688 service configuration, for instance by using @code{plain-file}, but it will be
20689 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20690 @file{share/ddclient} directory of the @code{ddclient} package.
20692 @c %start of fragment
20694 Available @code{ddclient-configuration} fields are:
20696 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20697 The ddclient package.
20701 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20702 The period after which ddclient will retry to check IP and domain name.
20704 Defaults to @samp{300}.
20708 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20709 Use syslog for the output.
20711 Defaults to @samp{#t}.
20715 @deftypevr {@code{ddclient-configuration} parameter} string mail
20718 Defaults to @samp{"root"}.
20722 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20723 Mail failed update to user.
20725 Defaults to @samp{"root"}.
20729 @deftypevr {@code{ddclient-configuration} parameter} string pid
20730 The ddclient PID file.
20732 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20736 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20737 Enable SSL support.
20739 Defaults to @samp{#t}.
20743 @deftypevr {@code{ddclient-configuration} parameter} string user
20744 Specifies the user name or ID that is used when running ddclient
20747 Defaults to @samp{"ddclient"}.
20751 @deftypevr {@code{ddclient-configuration} parameter} string group
20752 Group of the user who will run the ddclient program.
20754 Defaults to @samp{"ddclient"}.
20758 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20759 Secret file which will be appended to @file{ddclient.conf} file. This
20760 file contains credentials for use by ddclient. You are expected to
20761 create it manually.
20763 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20767 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20768 Extra options will be appended to @file{ddclient.conf} file.
20770 Defaults to @samp{()}.
20775 @c %end of fragment
20779 @subsection VPN Services
20780 @cindex VPN (virtual private network)
20781 @cindex virtual private network (VPN)
20783 The @code{(gnu services vpn)} module provides services related to
20784 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20785 your machine to connect to a VPN, and a @emph{server} service for your machine
20786 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20788 @deffn {Scheme Procedure} openvpn-client-service @
20789 [#:config (openvpn-client-configuration)]
20791 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20794 @deffn {Scheme Procedure} openvpn-server-service @
20795 [#:config (openvpn-server-configuration)]
20797 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20799 Both can be run simultaneously.
20802 @c %automatically generated documentation
20804 Available @code{openvpn-client-configuration} fields are:
20806 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20807 The OpenVPN package.
20811 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20812 The OpenVPN pid file.
20814 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20818 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20819 The protocol (UDP or TCP) used to open a channel between clients and
20822 Defaults to @samp{udp}.
20826 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20827 The device type used to represent the VPN connection.
20829 Defaults to @samp{tun}.
20833 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20834 The certificate authority to check connections against.
20836 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20840 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20841 The certificate of the machine the daemon is running on. It should be
20842 signed by the authority given in @code{ca}.
20844 Defaults to @samp{"/etc/openvpn/client.crt"}.
20848 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20849 The key of the machine the daemon is running on. It must be the key whose
20850 certificate is @code{cert}.
20852 Defaults to @samp{"/etc/openvpn/client.key"}.
20856 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20857 Whether to use the lzo compression algorithm.
20859 Defaults to @samp{#t}.
20863 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20864 Don't re-read key files across SIGUSR1 or --ping-restart.
20866 Defaults to @samp{#t}.
20870 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20871 Don't close and reopen TUN/TAP device or run up/down scripts across
20872 SIGUSR1 or --ping-restart restarts.
20874 Defaults to @samp{#t}.
20878 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20881 Defaults to @samp{3}.
20885 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20886 Add an additional layer of HMAC authentication on top of the TLS control
20887 channel to protect against DoS attacks.
20889 Defaults to @samp{#f}.
20893 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20894 Whether to check the server certificate has server usage extension.
20896 Defaults to @samp{#t}.
20900 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20901 Bind to a specific local port number.
20903 Defaults to @samp{#f}.
20907 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20908 Retry resolving server address.
20910 Defaults to @samp{#t}.
20914 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20915 A list of remote servers to connect to.
20917 Defaults to @samp{()}.
20919 Available @code{openvpn-remote-configuration} fields are:
20921 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20924 Defaults to @samp{"my-server"}.
20928 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20929 Port number the server listens to.
20931 Defaults to @samp{1194}.
20936 @c %end of automatic openvpn-client documentation
20938 @c %automatically generated documentation
20940 Available @code{openvpn-server-configuration} fields are:
20942 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20943 The OpenVPN package.
20947 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20948 The OpenVPN pid file.
20950 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20954 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20955 The protocol (UDP or TCP) used to open a channel between clients and
20958 Defaults to @samp{udp}.
20962 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20963 The device type used to represent the VPN connection.
20965 Defaults to @samp{tun}.
20969 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20970 The certificate authority to check connections against.
20972 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20976 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20977 The certificate of the machine the daemon is running on. It should be
20978 signed by the authority given in @code{ca}.
20980 Defaults to @samp{"/etc/openvpn/client.crt"}.
20984 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20985 The key of the machine the daemon is running on. It must be the key whose
20986 certificate is @code{cert}.
20988 Defaults to @samp{"/etc/openvpn/client.key"}.
20992 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20993 Whether to use the lzo compression algorithm.
20995 Defaults to @samp{#t}.
20999 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21000 Don't re-read key files across SIGUSR1 or --ping-restart.
21002 Defaults to @samp{#t}.
21006 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21007 Don't close and reopen TUN/TAP device or run up/down scripts across
21008 SIGUSR1 or --ping-restart restarts.
21010 Defaults to @samp{#t}.
21014 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21017 Defaults to @samp{3}.
21021 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21022 Add an additional layer of HMAC authentication on top of the TLS control
21023 channel to protect against DoS attacks.
21025 Defaults to @samp{#f}.
21029 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21030 Specifies the port number on which the server listens.
21032 Defaults to @samp{1194}.
21036 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21037 An ip and mask specifying the subnet inside the virtual network.
21039 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21043 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21044 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21046 Defaults to @samp{#f}.
21050 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21051 The Diffie-Hellman parameters file.
21053 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21057 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21058 The file that records client IPs.
21060 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21064 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21065 When true, the server will act as a gateway for its clients.
21067 Defaults to @samp{#f}.
21071 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21072 When true, clients are allowed to talk to each other inside the VPN.
21074 Defaults to @samp{#f}.
21078 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21079 Causes ping-like messages to be sent back and forth over the link so
21080 that each side knows when the other side has gone down. @code{keepalive}
21081 requires a pair. The first element is the period of the ping sending,
21082 and the second element is the timeout before considering the other side
21087 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21088 The maximum number of clients.
21090 Defaults to @samp{100}.
21094 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21095 The status file. This file shows a small report on current connection.
21096 It is truncated and rewritten every minute.
21098 Defaults to @samp{"/var/run/openvpn/status"}.
21102 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21103 The list of configuration for some clients.
21105 Defaults to @samp{()}.
21107 Available @code{openvpn-ccd-configuration} fields are:
21109 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21112 Defaults to @samp{"client"}.
21116 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21119 Defaults to @samp{#f}.
21123 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21126 Defaults to @samp{#f}.
21133 @c %end of automatic openvpn-server documentation
21136 @node Network File System
21137 @subsection Network File System
21140 The @code{(gnu services nfs)} module provides the following services,
21141 which are most commonly used in relation to mounting or exporting
21142 directory trees as @dfn{network file systems} (NFS).
21144 @subsubheading RPC Bind Service
21147 The RPC Bind service provides a facility to map program numbers into
21148 universal addresses.
21149 Many NFS related services use this facility. Hence it is automatically
21150 started when a dependent service starts.
21152 @defvr {Scheme Variable} rpcbind-service-type
21153 A service type for the RPC portmapper daemon.
21157 @deftp {Data Type} rpcbind-configuration
21158 Data type representing the configuration of the RPC Bind Service.
21159 This type has the following parameters:
21161 @item @code{rpcbind} (default: @code{rpcbind})
21162 The rpcbind package to use.
21164 @item @code{warm-start?} (default: @code{#t})
21165 If this parameter is @code{#t}, then the daemon will read a
21166 state file on startup thus reloading state information saved by a previous
21172 @subsubheading Pipefs Pseudo File System
21176 The pipefs file system is used to transfer NFS related data
21177 between the kernel and user space programs.
21179 @defvr {Scheme Variable} pipefs-service-type
21180 A service type for the pipefs pseudo file system.
21183 @deftp {Data Type} pipefs-configuration
21184 Data type representing the configuration of the pipefs pseudo file system service.
21185 This type has the following parameters:
21187 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21188 The directory to which the file system is to be attached.
21193 @subsubheading GSS Daemon Service
21196 @cindex global security system
21198 The @dfn{global security system} (GSS) daemon provides strong security for RPC
21200 Before exchanging RPC requests an RPC client must establish a security
21201 context. Typically this is done using the Kerberos command @command{kinit}
21202 or automatically at login time using PAM services (@pxref{Kerberos Services}).
21204 @defvr {Scheme Variable} gss-service-type
21205 A service type for the Global Security System (GSS) daemon.
21208 @deftp {Data Type} gss-configuration
21209 Data type representing the configuration of the GSS daemon service.
21210 This type has the following parameters:
21212 @item @code{nfs-utils} (default: @code{nfs-utils})
21213 The package in which the @command{rpc.gssd} command is to be found.
21215 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21216 The directory where the pipefs file system is mounted.
21222 @subsubheading IDMAP Daemon Service
21224 @cindex name mapper
21226 The idmap daemon service provides mapping between user IDs and user names.
21227 Typically it is required in order to access file systems mounted via NFSv4.
21229 @defvr {Scheme Variable} idmap-service-type
21230 A service type for the Identity Mapper (IDMAP) daemon.
21233 @deftp {Data Type} idmap-configuration
21234 Data type representing the configuration of the IDMAP daemon service.
21235 This type has the following parameters:
21237 @item @code{nfs-utils} (default: @code{nfs-utils})
21238 The package in which the @command{rpc.idmapd} command is to be found.
21240 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21241 The directory where the pipefs file system is mounted.
21243 @item @code{domain} (default: @code{#f})
21244 The local NFSv4 domain name.
21245 This must be a string or @code{#f}.
21246 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
21251 @node Continuous Integration
21252 @subsection Continuous Integration
21254 @cindex continuous integration
21255 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
21256 continuous integration tool for Guix. It can be used both for development and
21257 for providing substitutes to others (@pxref{Substitutes}).
21259 The @code{(gnu services cuirass)} module provides the following service.
21261 @defvr {Scheme Procedure} cuirass-service-type
21262 The type of the Cuirass service. Its value must be a
21263 @code{cuirass-configuration} object, as described below.
21266 To add build jobs, you have to set the @code{specifications} field of the
21267 configuration. Here is an example of a service that polls the Guix repository
21268 and builds the packages from a manifest. Some of the packages are defined in
21269 the @code{"custom-packages"} input, which is the equivalent of
21270 @code{GUIX_PACKAGE_PATH}.
21273 (define %cuirass-specs
21275 '((#:name . "my-manifest")
21276 (#:load-path-inputs . ("guix"))
21277 (#:package-path-inputs . ("custom-packages"))
21278 (#:proc-input . "guix")
21279 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
21280 (#:proc . cuirass-jobs)
21281 (#:proc-args . ((subset . "manifests")
21282 (systems . ("x86_64-linux"))
21283 (manifests . (("config" . "guix/manifest.scm")))))
21284 (#:inputs . (((#:name . "guix")
21285 (#:url . "git://git.savannah.gnu.org/guix.git")
21286 (#:load-path . ".")
21287 (#:branch . "master")
21288 (#:no-compile? . #t))
21289 ((#:name . "config")
21290 (#:url . "git://git.example.org/config.git")
21291 (#:load-path . ".")
21292 (#:branch . "master")
21293 (#:no-compile? . #t))
21294 ((#:name . "custom-packages")
21295 (#:url . "git://git.example.org/custom-packages.git")
21296 (#:load-path . ".")
21297 (#:branch . "master")
21298 (#:no-compile? . #t)))))))
21300 (service cuirass-service-type
21301 (cuirass-configuration
21302 (specifications %cuirass-specs)))
21305 While information related to build jobs is located directly in the
21306 specifications, global settings for the @command{cuirass} process are
21307 accessible in other @code{cuirass-configuration} fields.
21309 @deftp {Data Type} cuirass-configuration
21310 Data type representing the configuration of Cuirass.
21313 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
21314 Location of the log file.
21316 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
21317 Location of the repository cache.
21319 @item @code{user} (default: @code{"cuirass"})
21320 Owner of the @code{cuirass} process.
21322 @item @code{group} (default: @code{"cuirass"})
21323 Owner's group of the @code{cuirass} process.
21325 @item @code{interval} (default: @code{60})
21326 Number of seconds between the poll of the repositories followed by the
21329 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
21330 Location of sqlite database which contains the build results and previously
21331 added specifications.
21333 @item @code{ttl} (default: @code{(* 30 24 3600)})
21334 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
21335 are registered for build results. This means that build results are protected
21336 from garbage collection for at least @var{ttl} seconds.
21338 @item @code{port} (default: @code{8081})
21339 Port number used by the HTTP server.
21341 @item --listen=@var{host}
21342 Listen on the network interface for @var{host}. The default is to
21343 accept connections from localhost.
21345 @item @code{specifications} (default: @code{#~'()})
21346 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
21347 where a specification is an association list
21348 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
21349 keys are keywords (@code{#:keyword-example}) as shown in the example
21352 @item @code{use-substitutes?} (default: @code{#f})
21353 This allows using substitutes to avoid building every dependencies of a job
21356 @item @code{one-shot?} (default: @code{#f})
21357 Only evaluate specifications and build derivations once.
21359 @item @code{fallback?} (default: @code{#f})
21360 When substituting a pre-built binary fails, fall back to building
21363 @item @code{cuirass} (default: @code{cuirass})
21364 The Cuirass package to use.
21368 @node Power Management Services
21369 @subsection Power Management Services
21372 @cindex power management with TLP
21373 @subsubheading TLP daemon
21375 The @code{(gnu services pm)} module provides a Guix service definition
21376 for the Linux power management tool TLP.
21378 TLP enables various powersaving modes in userspace and kernel.
21379 Contrary to @code{upower-service}, it is not a passive,
21380 monitoring tool, as it will apply custom settings each time a new power
21381 source is detected. More information can be found at
21382 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
21384 @deffn {Scheme Variable} tlp-service-type
21385 The service type for the TLP tool. Its value should be a valid
21386 TLP configuration (see below). To use the default settings, simply
21389 (service tlp-service-type)
21393 By default TLP does not need much configuration but most TLP parameters
21394 can be tweaked using @code{tlp-configuration}.
21396 Each parameter definition is preceded by its type; for example,
21397 @samp{boolean foo} indicates that the @code{foo} parameter
21398 should be specified as a boolean. Types starting with
21399 @code{maybe-} denote parameters that won't show up in TLP config file
21400 when their value is @code{'disabled}.
21402 @c The following documentation was initially generated by
21403 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
21404 @c documentation is better, so we shouldn't hesitate to edit below as
21405 @c needed. However if the change you want to make to this documentation
21406 @c can be done in an automated way, it's probably easier to change
21407 @c (generate-documentation) than to make it below and have to deal with
21408 @c the churn as TLP updates.
21410 Available @code{tlp-configuration} fields are:
21412 @deftypevr {@code{tlp-configuration} parameter} package tlp
21417 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
21418 Set to true if you wish to enable TLP.
21420 Defaults to @samp{#t}.
21424 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
21425 Default mode when no power supply can be detected. Alternatives are AC
21428 Defaults to @samp{"AC"}.
21432 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
21433 Number of seconds Linux kernel has to wait after the disk goes idle,
21434 before syncing on AC.
21436 Defaults to @samp{0}.
21440 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
21441 Same as @code{disk-idle-ac} but on BAT mode.
21443 Defaults to @samp{2}.
21447 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
21448 Dirty pages flushing periodicity, expressed in seconds.
21450 Defaults to @samp{15}.
21454 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
21455 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
21457 Defaults to @samp{60}.
21461 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
21462 CPU frequency scaling governor on AC mode. With intel_pstate driver,
21463 alternatives are powersave and performance. With acpi-cpufreq driver,
21464 alternatives are ondemand, powersave, performance and conservative.
21466 Defaults to @samp{disabled}.
21470 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
21471 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
21473 Defaults to @samp{disabled}.
21477 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
21478 Set the min available frequency for the scaling governor on AC.
21480 Defaults to @samp{disabled}.
21484 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
21485 Set the max available frequency for the scaling governor on AC.
21487 Defaults to @samp{disabled}.
21491 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
21492 Set the min available frequency for the scaling governor on BAT.
21494 Defaults to @samp{disabled}.
21498 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
21499 Set the max available frequency for the scaling governor on BAT.
21501 Defaults to @samp{disabled}.
21505 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
21506 Limit the min P-state to control the power dissipation of the CPU, in AC
21507 mode. Values are stated as a percentage of the available performance.
21509 Defaults to @samp{disabled}.
21513 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
21514 Limit the max P-state to control the power dissipation of the CPU, in AC
21515 mode. Values are stated as a percentage of the available performance.
21517 Defaults to @samp{disabled}.
21521 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
21522 Same as @code{cpu-min-perf-on-ac} on BAT mode.
21524 Defaults to @samp{disabled}.
21528 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
21529 Same as @code{cpu-max-perf-on-ac} on BAT mode.
21531 Defaults to @samp{disabled}.
21535 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
21536 Enable CPU turbo boost feature on AC mode.
21538 Defaults to @samp{disabled}.
21542 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
21543 Same as @code{cpu-boost-on-ac?} on BAT mode.
21545 Defaults to @samp{disabled}.
21549 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
21550 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
21551 used under light load conditions.
21553 Defaults to @samp{#f}.
21557 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
21558 Same as @code{sched-powersave-on-ac?} but on BAT mode.
21560 Defaults to @samp{#t}.
21564 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
21565 Enable Linux kernel NMI watchdog.
21567 Defaults to @samp{#f}.
21571 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
21572 For Linux kernels with PHC patch applied, change CPU voltages. An
21573 example value would be @samp{"F:V F:V F:V F:V"}.
21575 Defaults to @samp{disabled}.
21579 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
21580 Set CPU performance versus energy saving policy on AC. Alternatives are
21581 performance, normal, powersave.
21583 Defaults to @samp{"performance"}.
21587 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
21588 Same as @code{energy-perf-policy-ac} but on BAT mode.
21590 Defaults to @samp{"powersave"}.
21594 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
21599 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
21600 Hard disk advanced power management level.
21604 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
21605 Same as @code{disk-apm-bat} but on BAT mode.
21609 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
21610 Hard disk spin down timeout. One value has to be specified for each
21611 declared hard disk.
21613 Defaults to @samp{disabled}.
21617 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
21618 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
21620 Defaults to @samp{disabled}.
21624 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
21625 Select IO scheduler for disk devices. One value has to be specified for
21626 each declared hard disk. Example alternatives are cfq, deadline and
21629 Defaults to @samp{disabled}.
21633 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
21634 SATA aggressive link power management (ALPM) level. Alternatives are
21635 min_power, medium_power, max_performance.
21637 Defaults to @samp{"max_performance"}.
21641 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
21642 Same as @code{sata-linkpwr-ac} but on BAT mode.
21644 Defaults to @samp{"min_power"}.
21648 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
21649 Exclude specified SATA host devices for link power management.
21651 Defaults to @samp{disabled}.
21655 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
21656 Enable Runtime Power Management for AHCI controller and disks on AC
21659 Defaults to @samp{disabled}.
21663 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21664 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21666 Defaults to @samp{disabled}.
21670 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21671 Seconds of inactivity before disk is suspended.
21673 Defaults to @samp{15}.
21677 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21678 PCI Express Active State Power Management level. Alternatives are
21679 default, performance, powersave.
21681 Defaults to @samp{"performance"}.
21685 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21686 Same as @code{pcie-aspm-ac} but on BAT mode.
21688 Defaults to @samp{"powersave"}.
21692 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21693 Radeon graphics clock speed level. Alternatives are low, mid, high,
21696 Defaults to @samp{"high"}.
21700 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21701 Same as @code{radeon-power-ac} but on BAT mode.
21703 Defaults to @samp{"low"}.
21707 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21708 Radeon dynamic power management method (DPM). Alternatives are battery,
21711 Defaults to @samp{"performance"}.
21715 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21716 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21718 Defaults to @samp{"battery"}.
21722 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21723 Radeon DPM performance level. Alternatives are auto, low, high.
21725 Defaults to @samp{"auto"}.
21729 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21730 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21732 Defaults to @samp{"auto"}.
21736 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21737 Wifi power saving mode.
21739 Defaults to @samp{#f}.
21743 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21744 Same as @code{wifi-power-ac?} but on BAT mode.
21746 Defaults to @samp{#t}.
21750 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21751 Disable wake on LAN.
21753 Defaults to @samp{#t}.
21757 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21758 Timeout duration in seconds before activating audio power saving on
21759 Intel HDA and AC97 devices. A value of 0 disables power saving.
21761 Defaults to @samp{0}.
21765 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21766 Same as @code{sound-powersave-ac} but on BAT mode.
21768 Defaults to @samp{1}.
21772 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21773 Disable controller in powersaving mode on Intel HDA devices.
21775 Defaults to @samp{#t}.
21779 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21780 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21781 powered on again by releasing (and reinserting) the eject lever or by
21782 pressing the disc eject button on newer models.
21784 Defaults to @samp{#f}.
21788 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21789 Name of the optical drive device to power off.
21791 Defaults to @samp{"sr0"}.
21795 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21796 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21799 Defaults to @samp{"on"}.
21803 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21804 Same as @code{runtime-pm-ac} but on BAT mode.
21806 Defaults to @samp{"auto"}.
21810 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21811 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21814 Defaults to @samp{#t}.
21818 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21819 Exclude specified PCI(e) device addresses from Runtime Power Management.
21821 Defaults to @samp{disabled}.
21825 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21826 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21831 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21832 Enable USB autosuspend feature.
21834 Defaults to @samp{#t}.
21838 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21839 Exclude specified devices from USB autosuspend.
21841 Defaults to @samp{disabled}.
21845 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21846 Exclude WWAN devices from USB autosuspend.
21848 Defaults to @samp{#t}.
21852 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21853 Include specified devices into USB autosuspend, even if they are already
21854 excluded by the driver or via @code{usb-blacklist-wwan?}.
21856 Defaults to @samp{disabled}.
21860 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21861 Enable USB autosuspend before shutdown.
21863 Defaults to @samp{disabled}.
21867 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21868 Restore radio device state (bluetooth, wifi, wwan) from previous
21869 shutdown on system startup.
21871 Defaults to @samp{#f}.
21876 @cindex CPU frequency scaling with thermald
21877 @subsubheading Thermald daemon
21879 The @code{(gnu services pm)} module provides an interface to
21880 thermald, a CPU frequency scaling service which helps prevent overheating.
21882 @defvr {Scheme Variable} thermald-service-type
21883 This is the service type for
21884 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21885 Thermal Daemon, which is responsible for controlling the thermal state
21886 of processors and preventing overheating.
21889 @deftp {Data Type} thermald-configuration
21890 Data type representing the configuration of @code{thermald-service-type}.
21893 @item @code{ignore-cpuid-check?} (default: @code{#f})
21894 Ignore cpuid check for supported CPU models.
21896 @item @code{thermald} (default: @var{thermald})
21897 Package object of thermald.
21902 @node Audio Services
21903 @subsection Audio Services
21905 The @code{(gnu services audio)} module provides a service to start MPD
21906 (the Music Player Daemon).
21909 @subsubheading Music Player Daemon
21911 The Music Player Daemon (MPD) is a service that can play music while
21912 being controlled from the local machine or over the network by a variety
21915 The following example shows how one might run @code{mpd} as user
21916 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21919 (service mpd-service-type
21925 @defvr {Scheme Variable} mpd-service-type
21926 The service type for @command{mpd}
21929 @deftp {Data Type} mpd-configuration
21930 Data type representing the configuration of @command{mpd}.
21933 @item @code{user} (default: @code{"mpd"})
21934 The user to run mpd as.
21936 @item @code{music-dir} (default: @code{"~/Music"})
21937 The directory to scan for music files.
21939 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21940 The directory to store playlists.
21942 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21943 The location of the music database.
21945 @item @code{state-file} (default: @code{"~/.mpd/state"})
21946 The location of the file that stores current MPD's state.
21948 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21949 The location of the sticker database.
21951 @item @code{port} (default: @code{"6600"})
21952 The port to run mpd on.
21954 @item @code{address} (default: @code{"any"})
21955 The address that mpd will bind to. To use a Unix domain socket,
21956 an absolute path can be specified here.
21961 @node Virtualization Services
21962 @subsection Virtualization services
21964 The @code{(gnu services virtualization)} module provides services for
21965 the libvirt and virtlog daemons, as well as other virtualization-related
21968 @subsubheading Libvirt daemon
21969 @code{libvirtd} is the server side daemon component of the libvirt
21970 virtualization management system. This daemon runs on host servers
21971 and performs required management tasks for virtualized guests.
21973 @deffn {Scheme Variable} libvirt-service-type
21974 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21975 Its value must be a @code{libvirt-configuration}.
21978 (service libvirt-service-type
21979 (libvirt-configuration
21980 (unix-sock-group "libvirt")
21981 (tls-port "16555")))
21985 @c Auto-generated with (generate-libvirt-documentation)
21986 Available @code{libvirt-configuration} fields are:
21988 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21993 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21994 Flag listening for secure TLS connections on the public TCP/IP port.
21995 must set @code{listen} for this to have any effect.
21997 It is necessary to setup a CA and issue server certificates before using
22000 Defaults to @samp{#t}.
22004 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22005 Listen for unencrypted TCP connections on the public TCP/IP port. must
22006 set @code{listen} for this to have any effect.
22008 Using the TCP socket requires SASL authentication by default. Only SASL
22009 mechanisms which support data encryption are allowed. This is
22010 DIGEST_MD5 and GSSAPI (Kerberos5)
22012 Defaults to @samp{#f}.
22016 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
22017 Port for accepting secure TLS connections This can be a port number, or
22020 Defaults to @samp{"16514"}.
22024 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
22025 Port for accepting insecure TCP connections This can be a port number,
22028 Defaults to @samp{"16509"}.
22032 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
22033 IP address or hostname used for client connections.
22035 Defaults to @samp{"0.0.0.0"}.
22039 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
22040 Flag toggling mDNS advertisement of the libvirt service.
22042 Alternatively can disable for all services on a host by stopping the
22045 Defaults to @samp{#f}.
22049 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
22050 Default mDNS advertisement name. This must be unique on the immediate
22053 Defaults to @samp{"Virtualization Host <hostname>"}.
22057 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
22058 UNIX domain socket group ownership. This can be used to allow a
22059 'trusted' set of users access to management capabilities without
22062 Defaults to @samp{"root"}.
22066 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
22067 UNIX socket permissions for the R/O socket. This is used for monitoring
22070 Defaults to @samp{"0777"}.
22074 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
22075 UNIX socket permissions for the R/W socket. Default allows only root.
22076 If PolicyKit is enabled on the socket, the default will change to allow
22077 everyone (eg, 0777)
22079 Defaults to @samp{"0770"}.
22083 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
22084 UNIX socket permissions for the admin socket. Default allows only owner
22085 (root), do not change it unless you are sure to whom you are exposing
22088 Defaults to @samp{"0777"}.
22092 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
22093 The directory in which sockets will be found/created.
22095 Defaults to @samp{"/var/run/libvirt"}.
22099 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
22100 Authentication scheme for UNIX read-only sockets. By default socket
22101 permissions allow anyone to connect
22103 Defaults to @samp{"polkit"}.
22107 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
22108 Authentication scheme for UNIX read-write sockets. By default socket
22109 permissions only allow root. If PolicyKit support was compiled into
22110 libvirt, the default will be to use 'polkit' auth.
22112 Defaults to @samp{"polkit"}.
22116 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
22117 Authentication scheme for TCP sockets. If you don't enable SASL, then
22118 all TCP traffic is cleartext. Don't do this outside of a dev/test
22121 Defaults to @samp{"sasl"}.
22125 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
22126 Authentication scheme for TLS sockets. TLS sockets already have
22127 encryption provided by the TLS layer, and limited authentication is done
22130 It is possible to make use of any SASL authentication mechanism as well,
22131 by using 'sasl' for this option
22133 Defaults to @samp{"none"}.
22137 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
22138 API access control scheme.
22140 By default an authenticated user is allowed access to all APIs. Access
22141 drivers can place restrictions on this.
22143 Defaults to @samp{()}.
22147 @deftypevr {@code{libvirt-configuration} parameter} string key-file
22148 Server key file path. If set to an empty string, then no private key is
22151 Defaults to @samp{""}.
22155 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
22156 Server key file path. If set to an empty string, then no certificate is
22159 Defaults to @samp{""}.
22163 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
22164 Server key file path. If set to an empty string, then no CA certificate
22167 Defaults to @samp{""}.
22171 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
22172 Certificate revocation list path. If set to an empty string, then no
22175 Defaults to @samp{""}.
22179 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
22180 Disable verification of our own server certificates.
22182 When libvirtd starts it performs some sanity checks against its own
22185 Defaults to @samp{#f}.
22189 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
22190 Disable verification of client certificates.
22192 Client certificate verification is the primary authentication mechanism.
22193 Any client which does not present a certificate signed by the CA will be
22196 Defaults to @samp{#f}.
22200 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
22201 Whitelist of allowed x509 Distinguished Name.
22203 Defaults to @samp{()}.
22207 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
22208 Whitelist of allowed SASL usernames. The format for username depends on
22209 the SASL authentication mechanism.
22211 Defaults to @samp{()}.
22215 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
22216 Override the compile time default TLS priority string. The default is
22217 usually "NORMAL" unless overridden at build time. Only set this is it
22218 is desired for libvirt to deviate from the global default settings.
22220 Defaults to @samp{"NORMAL"}.
22224 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
22225 Maximum number of concurrent client connections to allow over all
22228 Defaults to @samp{5000}.
22232 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
22233 Maximum length of queue of connections waiting to be accepted by the
22234 daemon. Note, that some protocols supporting retransmission may obey
22235 this so that a later reattempt at connection succeeds.
22237 Defaults to @samp{1000}.
22241 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
22242 Maximum length of queue of accepted but not yet authenticated clients.
22243 Set this to zero to turn this feature off
22245 Defaults to @samp{20}.
22249 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
22250 Number of workers to start up initially.
22252 Defaults to @samp{5}.
22256 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
22257 Maximum number of worker threads.
22259 If the number of active clients exceeds @code{min-workers}, then more
22260 threads are spawned, up to max_workers limit. Typically you'd want
22261 max_workers to equal maximum number of clients allowed.
22263 Defaults to @samp{20}.
22267 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
22268 Number of priority workers. If all workers from above pool are stuck,
22269 some calls marked as high priority (notably domainDestroy) can be
22270 executed in this pool.
22272 Defaults to @samp{5}.
22276 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
22277 Total global limit on concurrent RPC calls.
22279 Defaults to @samp{20}.
22283 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
22284 Limit on concurrent requests from a single client connection. To avoid
22285 one client monopolizing the server this should be a small fraction of
22286 the global max_requests and max_workers parameter.
22288 Defaults to @samp{5}.
22292 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
22293 Same as @code{min-workers} but for the admin interface.
22295 Defaults to @samp{1}.
22299 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
22300 Same as @code{max-workers} but for the admin interface.
22302 Defaults to @samp{5}.
22306 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
22307 Same as @code{max-clients} but for the admin interface.
22309 Defaults to @samp{5}.
22313 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
22314 Same as @code{max-queued-clients} but for the admin interface.
22316 Defaults to @samp{5}.
22320 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
22321 Same as @code{max-client-requests} but for the admin interface.
22323 Defaults to @samp{5}.
22327 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
22328 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
22330 Defaults to @samp{3}.
22334 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
22337 A filter allows to select a different logging level for a given category
22338 of logs The format for a filter is one of:
22349 where @code{name} is a string which is matched against the category
22350 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
22351 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
22352 be a substring of the full category name, in order to match multiple
22353 similar categories), the optional "+" prefix tells libvirt to log stack
22354 trace for each message matching name, and @code{x} is the minimal level
22355 where matching messages should be logged:
22372 Multiple filters can be defined in a single filters statement, they just
22373 need to be separated by spaces.
22375 Defaults to @samp{"3:remote 4:event"}.
22379 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
22382 An output is one of the places to save logging information. The format
22383 for an output can be:
22387 output goes to stderr
22389 @item x:syslog:name
22390 use syslog for the output and use the given name as the ident
22392 @item x:file:file_path
22393 output to a file, with the given filepath
22396 output to journald logging system
22400 In all case the x prefix is the minimal level, acting as a filter
22417 Multiple outputs can be defined, they just need to be separated by
22420 Defaults to @samp{"3:stderr"}.
22424 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
22425 Allows usage of the auditing subsystem to be altered
22429 0: disable all auditing
22432 1: enable auditing, only if enabled on host
22435 2: enable auditing, and exit if disabled on host.
22439 Defaults to @samp{1}.
22443 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
22444 Send audit messages via libvirt logging infrastructure.
22446 Defaults to @samp{#f}.
22450 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
22451 Host UUID. UUID must not have all digits be the same.
22453 Defaults to @samp{""}.
22457 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
22458 Source to read host UUID.
22462 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
22465 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
22469 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
22472 Defaults to @samp{"smbios"}.
22476 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
22477 A keepalive message is sent to a client after @code{keepalive_interval}
22478 seconds of inactivity to check if the client is still responding. If
22479 set to -1, libvirtd will never send keepalive requests; however clients
22480 can still send them and the daemon will send responses.
22482 Defaults to @samp{5}.
22486 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
22487 Maximum number of keepalive messages that are allowed to be sent to the
22488 client without getting any response before the connection is considered
22491 In other words, the connection is automatically closed approximately
22492 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
22493 the last message received from the client. When @code{keepalive-count}
22494 is set to 0, connections will be automatically closed after
22495 @code{keepalive-interval} seconds of inactivity without sending any
22496 keepalive messages.
22498 Defaults to @samp{5}.
22502 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
22503 Same as above but for admin interface.
22505 Defaults to @samp{5}.
22509 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
22510 Same as above but for admin interface.
22512 Defaults to @samp{5}.
22516 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
22517 Timeout for Open vSwitch calls.
22519 The @code{ovs-vsctl} utility is used for the configuration and its
22520 timeout option is set by default to 5 seconds to avoid potential
22521 infinite waits blocking libvirt.
22523 Defaults to @samp{5}.
22527 @c %end of autogenerated docs
22529 @subsubheading Virtlog daemon
22530 The virtlogd service is a server side daemon component of libvirt that is
22531 used to manage logs from virtual machine consoles.
22533 This daemon is not used directly by libvirt client applications, rather it
22534 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
22535 standalone daemon, the main @code{libvirtd} daemon can be restarted without
22536 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
22537 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
22539 @deffn {Scheme Variable} virtlog-service-type
22540 This is the type of the virtlog daemon.
22541 Its value must be a @code{virtlog-configuration}.
22544 (service virtlog-service-type
22545 (virtlog-configuration
22546 (max-clients 1000)))
22550 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
22551 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
22553 Defaults to @samp{3}.
22557 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
22560 A filter allows to select a different logging level for a given category
22561 of logs The format for a filter is one of:
22572 where @code{name} is a string which is matched against the category
22573 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
22574 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
22575 be a substring of the full category name, in order to match multiple
22576 similar categories), the optional "+" prefix tells libvirt to log stack
22577 trace for each message matching name, and @code{x} is the minimal level
22578 where matching messages should be logged:
22595 Multiple filters can be defined in a single filters statement, they just
22596 need to be separated by spaces.
22598 Defaults to @samp{"3:remote 4:event"}.
22602 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
22605 An output is one of the places to save logging information The format
22606 for an output can be:
22610 output goes to stderr
22612 @item x:syslog:name
22613 use syslog for the output and use the given name as the ident
22615 @item x:file:file_path
22616 output to a file, with the given filepath
22619 output to journald logging system
22623 In all case the x prefix is the minimal level, acting as a filter
22640 Multiple outputs can be defined, they just need to be separated by
22643 Defaults to @samp{"3:stderr"}.
22647 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
22648 Maximum number of concurrent client connections to allow over all
22651 Defaults to @samp{1024}.
22655 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
22656 Maximum file size before rolling over.
22658 Defaults to @samp{2MB}
22662 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22663 Maximum number of backup files to keep.
22665 Defaults to @samp{3}
22669 @subsubheading Transparent Emulation with QEMU
22672 @cindex @code{binfmt_misc}
22673 @code{qemu-binfmt-service-type} provides support for transparent
22674 emulation of program binaries built for different architectures---e.g.,
22675 it allows you to transparently execute an ARMv7 program on an x86_64
22676 machine. It achieves this by combining the @uref{https://www.qemu.org,
22677 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22679 @defvr {Scheme Variable} qemu-binfmt-service-type
22680 This is the type of the QEMU/binfmt service for transparent emulation.
22681 Its value must be a @code{qemu-binfmt-configuration} object, which
22682 specifies the QEMU package to use as well as the architecture we want to
22686 (service qemu-binfmt-service-type
22687 (qemu-binfmt-configuration
22688 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22691 In this example, we enable transparent emulation for the ARM and aarch64
22692 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22693 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22694 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22697 @deftp {Data Type} qemu-binfmt-configuration
22698 This is the configuration for the @code{qemu-binfmt} service.
22701 @item @code{platforms} (default: @code{'()})
22702 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22703 object} as returned by @code{lookup-qemu-platforms} (see below).
22705 @item @code{guix-support?} (default: @code{#f})
22706 When it is true, QEMU and all its dependencies are added to the build
22707 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22708 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22709 handlers to be used within the build environment, which in turn means
22710 that you can transparently build programs for another architecture.
22712 For example, let's suppose you're on an x86_64 machine and you have this
22716 (service qemu-binfmt-service-type
22717 (qemu-binfmt-configuration
22718 (platforms (lookup-qemu-platforms "arm"))
22719 (guix-support? #t)))
22725 guix build -s armhf-linux inkscape
22729 and it will build Inkscape for ARMv7 @emph{as if it were a native
22730 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22731 if you'd like to test a package build for an architecture you don't have
22734 @item @code{qemu} (default: @code{qemu})
22735 The QEMU package to use.
22739 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22740 Return the list of QEMU platform objects corresponding to
22741 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22742 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22743 @code{"mips64el"}, and so on.
22746 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22747 Return true if @var{obj} is a platform object.
22750 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22751 Return the name of @var{platform}---a string such as @code{"arm"}.
22754 @node Version Control Services
22755 @subsection Version Control Services
22757 The @code{(gnu services version-control)} module provides a service to
22758 allow remote access to local Git repositories. There are three options:
22759 the @code{git-daemon-service}, which provides access to repositories via
22760 the @code{git://} unsecured TCP-based protocol, extending the
22761 @code{nginx} web server to proxy some requests to
22762 @code{git-http-backend}, or providing a web interface with
22763 @code{cgit-service-type}.
22765 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22767 Return a service that runs @command{git daemon}, a simple TCP server to
22768 expose repositories over the Git protocol for anonymous access.
22770 The optional @var{config} argument should be a
22771 @code{<git-daemon-configuration>} object, by default it allows read-only
22772 access to exported@footnote{By creating the magic file
22773 "git-daemon-export-ok" in the repository directory.} repositories under
22778 @deftp {Data Type} git-daemon-configuration
22779 Data type representing the configuration for @code{git-daemon-service}.
22782 @item @code{package} (default: @var{git})
22783 Package object of the Git distributed version control system.
22785 @item @code{export-all?} (default: @var{#f})
22786 Whether to allow access for all Git repositories, even if they do not
22787 have the @file{git-daemon-export-ok} file.
22789 @item @code{base-path} (default: @file{/srv/git})
22790 Whether to remap all the path requests as relative to the given path.
22791 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22792 then if you later try to pull @code{git://example.com/hello.git}, git
22793 daemon will interpret the path as @code{/srv/git/hello.git}.
22795 @item @code{user-path} (default: @var{#f})
22796 Whether to allow @code{~user} notation to be used in requests. When
22797 specified with empty string, requests to @code{git://host/~alice/foo} is
22798 taken as a request to access @code{foo} repository in the home directory
22799 of user @code{alice}. If @var{(user-path "path")} is specified, the
22800 same request is taken as a request to access @code{path/foo} repository
22801 in the home directory of user @code{alice}.
22803 @item @code{listen} (default: @var{'()})
22804 Whether to listen on specific IP addresses or hostnames, defaults to
22807 @item @code{port} (default: @var{#f})
22808 Whether to listen on an alternative port, which defaults to 9418.
22810 @item @code{whitelist} (default: @var{'()})
22811 If not empty, only allow access to this list of directories.
22813 @item @code{extra-options} (default: @var{'()})
22814 Extra options will be passed to @code{git daemon}, please run
22815 @command{man git-daemon} for more information.
22820 The @code{git://} protocol lacks authentication. When you pull from a
22821 repository fetched via @code{git://}, you don't know whether the data you
22822 receive was modified or is even coming from the specified host, and your
22823 connection is subject to eavesdropping. It's better to use an authenticated
22824 and encrypted transport, such as @code{https}. Although Git allows you
22825 to serve repositories using unsophisticated file-based web servers,
22826 there is a faster protocol implemented by the @code{git-http-backend}
22827 program. This program is the back-end of a proper Git web service. It
22828 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22829 on running the necessary @code{fcgiwrap} daemon.
22831 Guix has a separate configuration data type for serving Git repositories
22834 @deftp {Data Type} git-http-configuration
22835 Data type representing the configuration for @code{git-http-service}.
22838 @item @code{package} (default: @var{git})
22839 Package object of the Git distributed version control system.
22841 @item @code{git-root} (default: @file{/srv/git})
22842 Directory containing the Git repositories to expose to the world.
22844 @item @code{export-all?} (default: @var{#f})
22845 Whether to expose access for all Git repositories in @var{git-root},
22846 even if they do not have the @file{git-daemon-export-ok} file.
22848 @item @code{uri-path} (default: @file{/git/})
22849 Path prefix for Git access. With the default @code{/git/} prefix, this
22850 will map @code{http://@var{server}/git/@var{repo}.git} to
22851 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22852 with this prefix are not passed on to this Git instance.
22854 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22855 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22860 There is no @code{git-http-service-type}, currently; instead you can
22861 create an @code{nginx-location-configuration} from a
22862 @code{git-http-configuration} and then add that location to a web
22865 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22866 [config=(git-http-configuration)]
22867 Compute an @code{nginx-location-configuration} that corresponds to the
22868 given Git http configuration. An example nginx service definition to
22869 serve the default @file{/srv/git} over HTTPS might be:
22872 (service nginx-service-type
22873 (nginx-configuration
22876 (nginx-server-configuration
22877 (listen '("443 ssl"))
22878 (server-name "git.my-host.org")
22880 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22881 (ssl-certificate-key
22882 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22885 (git-http-nginx-location-configuration
22886 (git-http-configuration (uri-path "/"))))))))))
22889 This example assumes that you are using Let's Encrypt to get your TLS
22890 certificate. @xref{Certificate Services}. The default @code{certbot}
22891 service will redirect all HTTP traffic on @code{git.my-host.org} to
22892 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22893 system services. @xref{Web Services}.
22896 @subsubheading Cgit Service
22898 @cindex Cgit service
22899 @cindex Git, web interface
22900 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22901 repositories written in C.
22903 The following example will configure the service with default values.
22904 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22907 (service cgit-service-type)
22910 The @code{file-object} type designates either a file-like object
22911 (@pxref{G-Expressions, file-like objects}) or a string.
22913 @c %start of fragment
22915 Available @code{cgit-configuration} fields are:
22917 @deftypevr {@code{cgit-configuration} parameter} package package
22922 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22923 NGINX configuration.
22927 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22928 Specifies a command which will be invoked to format the content of about
22929 pages (both top-level and for each repository).
22931 Defaults to @samp{""}.
22935 @deftypevr {@code{cgit-configuration} parameter} string agefile
22936 Specifies a path, relative to each repository path, which can be used to
22937 specify the date and time of the youngest commit in the repository.
22939 Defaults to @samp{""}.
22943 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22944 Specifies a command that will be invoked for authenticating repository
22947 Defaults to @samp{""}.
22951 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22952 Flag which, when set to @samp{age}, enables date ordering in the branch
22953 ref list, and when set @samp{name} enables ordering by branch name.
22955 Defaults to @samp{"name"}.
22959 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22960 Path used to store the cgit cache entries.
22962 Defaults to @samp{"/var/cache/cgit"}.
22966 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22967 Number which specifies the time-to-live, in minutes, for the cached
22968 version of repository pages accessed with a fixed SHA1.
22970 Defaults to @samp{-1}.
22974 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22975 Number which specifies the time-to-live, in minutes, for the cached
22976 version of repository pages accessed without a fixed SHA1.
22978 Defaults to @samp{5}.
22982 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22983 Number which specifies the time-to-live, in minutes, for the cached
22984 version of the repository summary page.
22986 Defaults to @samp{5}.
22990 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22991 Number which specifies the time-to-live, in minutes, for the cached
22992 version of the repository index page.
22994 Defaults to @samp{5}.
22998 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22999 Number which specifies the time-to-live, in minutes, for the result of
23000 scanning a path for Git repositories.
23002 Defaults to @samp{15}.
23006 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23007 Number which specifies the time-to-live, in minutes, for the cached
23008 version of the repository about page.
23010 Defaults to @samp{15}.
23014 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
23015 Number which specifies the time-to-live, in minutes, for the cached
23016 version of snapshots.
23018 Defaults to @samp{5}.
23022 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
23023 The maximum number of entries in the cgit cache. When set to @samp{0},
23024 caching is disabled.
23026 Defaults to @samp{0}.
23030 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
23031 Sort items in the repo list case sensitively.
23033 Defaults to @samp{#t}.
23037 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
23038 List of common prefixes which, when combined with a repository URL,
23039 generates valid clone URLs for the repository.
23041 Defaults to @samp{()}.
23045 @deftypevr {@code{cgit-configuration} parameter} list clone-url
23046 List of @code{clone-url} templates.
23048 Defaults to @samp{()}.
23052 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
23053 Command which will be invoked to format commit messages.
23055 Defaults to @samp{""}.
23059 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
23060 Flag which, when set to @samp{date}, enables strict date ordering in the
23061 commit log, and when set to @samp{topo} enables strict topological
23064 Defaults to @samp{"git log"}.
23068 @deftypevr {@code{cgit-configuration} parameter} file-object css
23069 URL which specifies the css document to include in all cgit pages.
23071 Defaults to @samp{"/share/cgit/cgit.css"}.
23075 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
23076 Specifies a command which will be invoked to format names and email
23077 address of committers, authors, and taggers, as represented in various
23078 places throughout the cgit interface.
23080 Defaults to @samp{""}.
23084 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
23085 Flag which, when set to @samp{#t}, will make cgit generate a HTML
23086 fragment suitable for embedding in other HTML pages.
23088 Defaults to @samp{#f}.
23092 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
23093 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
23094 commit history graph to the left of the commit messages in the
23095 repository log page.
23097 Defaults to @samp{#f}.
23101 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
23102 Flag which, when set to @samp{#t}, allows all filter settings to be
23103 overridden in repository-specific cgitrc files.
23105 Defaults to @samp{#f}.
23109 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
23110 Flag which, when set to @samp{#t}, allows users to follow a file in the
23113 Defaults to @samp{#f}.
23117 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
23118 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
23121 Defaults to @samp{#t}.
23125 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
23126 Flag which, when set to @samp{#t}, will make cgit generate extra links
23127 "summary", "commit", "tree" for each repo in the repository index.
23129 Defaults to @samp{#f}.
23133 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
23134 Flag which, when set to @samp{#t}, will make cgit display the owner of
23135 each repo in the repository index.
23137 Defaults to @samp{#t}.
23141 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
23142 Flag which, when set to @samp{#t}, will make cgit print the number of
23143 modified files for each commit on the repository log page.
23145 Defaults to @samp{#f}.
23149 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
23150 Flag which, when set to @samp{#t}, will make cgit print the number of
23151 added and removed lines for each commit on the repository log page.
23153 Defaults to @samp{#f}.
23157 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
23158 Flag which, when set to @code{#t}, will make cgit display remote
23159 branches in the summary and refs views.
23161 Defaults to @samp{#f}.
23165 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
23166 Flag which, when set to @code{1}, will make cgit use the subject of the
23167 parent commit as link text when generating links to parent commits in
23170 Defaults to @samp{#f}.
23174 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
23175 Flag which, when set to @samp{#t}, will make cgit use the subject of the
23176 parent commit as link text when generating links to parent commits in
23179 Defaults to @samp{#f}.
23183 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
23184 Flag which, when set to @samp{#t}, will make cgit generate linenumber
23185 links for plaintext blobs printed in the tree view.
23187 Defaults to @samp{#t}.
23191 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
23192 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
23193 set any repo specific settings.
23195 Defaults to @samp{#f}.
23199 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
23200 URL used as link to a shortcut icon for cgit.
23202 Defaults to @samp{"/favicon.ico"}.
23206 @deftypevr {@code{cgit-configuration} parameter} string footer
23207 The content of the file specified with this option will be included
23208 verbatim at the bottom of all pages (i.e.@: it replaces the standard
23209 "generated by..."@: message).
23211 Defaults to @samp{""}.
23215 @deftypevr {@code{cgit-configuration} parameter} string head-include
23216 The content of the file specified with this option will be included
23217 verbatim in the HTML HEAD section on all pages.
23219 Defaults to @samp{""}.
23223 @deftypevr {@code{cgit-configuration} parameter} string header
23224 The content of the file specified with this option will be included
23225 verbatim at the top of all pages.
23227 Defaults to @samp{""}.
23231 @deftypevr {@code{cgit-configuration} parameter} file-object include
23232 Name of a configfile to include before the rest of the current config-
23235 Defaults to @samp{""}.
23239 @deftypevr {@code{cgit-configuration} parameter} string index-header
23240 The content of the file specified with this option will be included
23241 verbatim above the repository index.
23243 Defaults to @samp{""}.
23247 @deftypevr {@code{cgit-configuration} parameter} string index-info
23248 The content of the file specified with this option will be included
23249 verbatim below the heading on the repository index page.
23251 Defaults to @samp{""}.
23255 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
23256 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
23257 in the servers timezone.
23259 Defaults to @samp{#f}.
23263 @deftypevr {@code{cgit-configuration} parameter} file-object logo
23264 URL which specifies the source of an image which will be used as a logo
23267 Defaults to @samp{"/share/cgit/cgit.png"}.
23271 @deftypevr {@code{cgit-configuration} parameter} string logo-link
23272 URL loaded when clicking on the cgit logo image.
23274 Defaults to @samp{""}.
23278 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
23279 Command which will be invoked to format the Owner column of the main
23282 Defaults to @samp{""}.
23286 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
23287 Number of items to display in atom feeds view.
23289 Defaults to @samp{10}.
23293 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
23294 Number of entries to list per page in "log" view.
23296 Defaults to @samp{50}.
23300 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
23301 Number of commit message characters to display in "log" view.
23303 Defaults to @samp{80}.
23307 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
23308 Specifies the number of entries to list per page on the repository index
23311 Defaults to @samp{50}.
23315 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
23316 Specifies the maximum number of repo description characters to display
23317 on the repository index page.
23319 Defaults to @samp{80}.
23323 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
23324 Specifies the maximum size of a blob to display HTML for in KBytes.
23326 Defaults to @samp{0}.
23330 @deftypevr {@code{cgit-configuration} parameter} string max-stats
23331 Maximum statistics period. Valid values are @samp{week},@samp{month},
23332 @samp{quarter} and @samp{year}.
23334 Defaults to @samp{""}.
23338 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
23339 Mimetype for the specified filename extension.
23341 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
23342 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
23343 "image/png") (svg "image/svg+xml"))}.
23347 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
23348 Specifies the file to use for automatic mimetype lookup.
23350 Defaults to @samp{""}.
23354 @deftypevr {@code{cgit-configuration} parameter} string module-link
23355 Text which will be used as the formatstring for a hyperlink when a
23356 submodule is printed in a directory listing.
23358 Defaults to @samp{""}.
23362 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
23363 If set to the value @samp{#t} caching will be disabled.
23365 Defaults to @samp{#f}.
23369 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
23370 If set to @samp{#t} showing full author email addresses will be
23373 Defaults to @samp{#f}.
23377 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
23378 Flag which, when set to @samp{#t}, will make cgit omit the standard
23379 header on all pages.
23381 Defaults to @samp{#f}.
23385 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
23386 A list of subdirectories inside of @code{repository-directory}, relative
23387 to it, that should loaded as Git repositories. An empty list means that
23388 all subdirectories will be loaded.
23390 Defaults to @samp{()}.
23394 @deftypevr {@code{cgit-configuration} parameter} file-object readme
23395 Text which will be used as default value for @code{cgit-repo-readme}.
23397 Defaults to @samp{""}.
23401 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
23402 If set to @code{#t} and @code{repository-directory} is enabled, if any
23403 repositories are found with a suffix of @code{.git}, this suffix will be
23404 removed for the URL and name.
23406 Defaults to @samp{#f}.
23410 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
23411 Maximum number of files to consider when detecting renames.
23413 Defaults to @samp{-1}.
23417 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
23418 The way in which repositories in each section are sorted.
23420 Defaults to @samp{""}.
23424 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
23425 Text used as content for the @code{robots} meta-tag.
23427 Defaults to @samp{("noindex" "nofollow")}.
23431 @deftypevr {@code{cgit-configuration} parameter} string root-desc
23432 Text printed below the heading on the repository index page.
23434 Defaults to @samp{"a fast webinterface for the git dscm"}.
23438 @deftypevr {@code{cgit-configuration} parameter} string root-readme
23439 The content of the file specified with this option will be included
23440 verbatim below thef "about" link on the repository index page.
23442 Defaults to @samp{""}.
23446 @deftypevr {@code{cgit-configuration} parameter} string root-title
23447 Text printed as heading on the repository index page.
23449 Defaults to @samp{""}.
23453 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
23454 If set to @samp{#t} and repository-directory is enabled,
23455 repository-directory will recurse into directories whose name starts
23456 with a period. Otherwise, repository-directory will stay away from such
23457 directories, considered as "hidden". Note that this does not apply to
23458 the ".git" directory in non-bare repos.
23460 Defaults to @samp{#f}.
23464 @deftypevr {@code{cgit-configuration} parameter} list snapshots
23465 Text which specifies the default set of snapshot formats that cgit
23466 generates links for.
23468 Defaults to @samp{()}.
23472 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
23473 Name of the directory to scan for repositories (represents
23476 Defaults to @samp{"/srv/git"}.
23480 @deftypevr {@code{cgit-configuration} parameter} string section
23481 The name of the current repository section - all repositories defined
23482 after this option will inherit the current section name.
23484 Defaults to @samp{""}.
23488 @deftypevr {@code{cgit-configuration} parameter} string section-sort
23489 Flag which, when set to @samp{1}, will sort the sections on the
23490 repository listing by name.
23492 Defaults to @samp{""}.
23496 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
23497 A number which, if defined prior to repository-directory, specifies how
23498 many path elements from each repo path to use as a default section name.
23500 Defaults to @samp{0}.
23504 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
23505 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
23508 Defaults to @samp{#f}.
23512 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
23513 Specifies a command which will be invoked to format plaintext blobs in
23516 Defaults to @samp{""}.
23520 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
23521 Specifies the number of branches to display in the repository "summary"
23524 Defaults to @samp{10}.
23528 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
23529 Specifies the number of log entries to display in the repository
23532 Defaults to @samp{10}.
23536 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
23537 Specifies the number of tags to display in the repository "summary"
23540 Defaults to @samp{10}.
23544 @deftypevr {@code{cgit-configuration} parameter} string strict-export
23545 Filename which, if specified, needs to be present within the repository
23546 for cgit to allow access to that repository.
23548 Defaults to @samp{""}.
23552 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
23553 URL which, if specified, will be used as root for all cgit links.
23555 Defaults to @samp{"/"}.
23559 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
23560 A list of @dfn{cgit-repo} records to use with config.
23562 Defaults to @samp{()}.
23564 Available @code{repository-cgit-configuration} fields are:
23566 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
23567 A mask of snapshot formats for this repo that cgit generates links for,
23568 restricted by the global @code{snapshots} setting.
23570 Defaults to @samp{()}.
23574 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
23575 Override the default @code{source-filter}.
23577 Defaults to @samp{""}.
23581 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
23582 The relative URL used to access the repository.
23584 Defaults to @samp{""}.
23588 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
23589 Override the default @code{about-filter}.
23591 Defaults to @samp{""}.
23595 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
23596 Flag which, when set to @samp{age}, enables date ordering in the branch
23597 ref list, and when set to @samp{name} enables ordering by branch name.
23599 Defaults to @samp{""}.
23603 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
23604 A list of URLs which can be used to clone repo.
23606 Defaults to @samp{()}.
23610 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
23611 Override the default @code{commit-filter}.
23613 Defaults to @samp{""}.
23617 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
23618 Flag which, when set to @samp{date}, enables strict date ordering in the
23619 commit log, and when set to @samp{topo} enables strict topological
23622 Defaults to @samp{""}.
23626 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
23627 The name of the default branch for this repository. If no such branch
23628 exists in the repository, the first branch name (when sorted) is used as
23629 default instead. By default branch pointed to by HEAD, or "master" if
23630 there is no suitable HEAD.
23632 Defaults to @samp{""}.
23636 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
23637 The value to show as repository description.
23639 Defaults to @samp{""}.
23643 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
23644 The value to show as repository homepage.
23646 Defaults to @samp{""}.
23650 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
23651 Override the default @code{email-filter}.
23653 Defaults to @samp{""}.
23657 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
23658 A flag which can be used to disable the global setting
23659 @code{enable-commit-graph?}.
23661 Defaults to @samp{disabled}.
23665 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23666 A flag which can be used to disable the global setting
23667 @code{enable-log-filecount?}.
23669 Defaults to @samp{disabled}.
23673 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23674 A flag which can be used to disable the global setting
23675 @code{enable-log-linecount?}.
23677 Defaults to @samp{disabled}.
23681 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23682 Flag which, when set to @code{#t}, will make cgit display remote
23683 branches in the summary and refs views.
23685 Defaults to @samp{disabled}.
23689 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23690 A flag which can be used to override the global setting
23691 @code{enable-subject-links?}.
23693 Defaults to @samp{disabled}.
23697 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23698 A flag which can be used to override the global setting
23699 @code{enable-html-serving?}.
23701 Defaults to @samp{disabled}.
23705 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23706 Flag which, when set to @code{#t}, hides the repository from the
23709 Defaults to @samp{#f}.
23713 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23714 Flag which, when set to @samp{#t}, ignores the repository.
23716 Defaults to @samp{#f}.
23720 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23721 URL which specifies the source of an image which will be used as a logo
23722 on this repo’s pages.
23724 Defaults to @samp{""}.
23728 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23729 URL loaded when clicking on the cgit logo image.
23731 Defaults to @samp{""}.
23735 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23736 Override the default @code{owner-filter}.
23738 Defaults to @samp{""}.
23742 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23743 Text which will be used as the formatstring for a hyperlink when a
23744 submodule is printed in a directory listing. The arguments for the
23745 formatstring are the path and SHA1 of the submodule commit.
23747 Defaults to @samp{""}.
23751 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23752 Text which will be used as the formatstring for a hyperlink when a
23753 submodule with the specified subdirectory path is printed in a directory
23756 Defaults to @samp{()}.
23760 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23761 Override the default maximum statistics period.
23763 Defaults to @samp{""}.
23767 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23768 The value to show as repository name.
23770 Defaults to @samp{""}.
23774 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23775 A value used to identify the owner of the repository.
23777 Defaults to @samp{""}.
23781 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23782 An absolute path to the repository directory.
23784 Defaults to @samp{""}.
23788 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23789 A path (relative to repo) which specifies a file to include verbatim as
23790 the "About" page for this repo.
23792 Defaults to @samp{""}.
23796 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23797 The name of the current repository section - all repositories defined
23798 after this option will inherit the current section name.
23800 Defaults to @samp{""}.
23804 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23805 Extra options will be appended to cgitrc file.
23807 Defaults to @samp{()}.
23813 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23814 Extra options will be appended to cgitrc file.
23816 Defaults to @samp{()}.
23821 @c %end of fragment
23823 However, it could be that you just want to get a @code{cgitrc} up and
23824 running. In that case, you can pass an @code{opaque-cgit-configuration}
23825 as a record to @code{cgit-service-type}. As its name indicates, an
23826 opaque configuration does not have easy reflective capabilities.
23828 Available @code{opaque-cgit-configuration} fields are:
23830 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23834 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23835 The contents of the @code{cgitrc}, as a string.
23838 For example, if your @code{cgitrc} is just the empty string, you
23839 could instantiate a cgit service like this:
23842 (service cgit-service-type
23843 (opaque-cgit-configuration
23847 @subsubheading Gitolite Service
23849 @cindex Gitolite service
23850 @cindex Git, hosting
23851 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23852 repositories on a central server.
23854 Gitolite can handle multiple repositories and users, and supports flexible
23855 configuration of the permissions for the users on the repositories.
23857 The following example will configure Gitolite using the default @code{git}
23858 user, and the provided SSH public key.
23861 (service gitolite-service-type
23862 (gitolite-configuration
23863 (admin-pubkey (plain-file
23865 "ssh-rsa AAAA... guix@@example.com"))))
23868 Gitolite is configured through a special admin repository which you can clone,
23869 for example, if you setup Gitolite on @code{example.com}, you would run the
23870 following command to clone the admin repository.
23873 git clone git@@example.com:gitolite-admin
23876 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23877 be inserted in to the @file{keydir} directory in the gitolite-admin
23878 repository. If this results in a change in the repository, it will be
23879 committed using the message ``gitolite setup by GNU Guix''.
23881 @deftp {Data Type} gitolite-configuration
23882 Data type representing the configuration for @code{gitolite-service-type}.
23885 @item @code{package} (default: @var{gitolite})
23886 Gitolite package to use.
23888 @item @code{user} (default: @var{git})
23889 User to use for Gitolite. This will be user that you use when accessing
23892 @item @code{group} (default: @var{git})
23893 Group to use for Gitolite.
23895 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23896 Directory in which to store the Gitolite configuration and repositories.
23898 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23899 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23900 representing the configuration for Gitolite.
23902 @item @code{admin-pubkey} (default: @var{#f})
23903 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23904 setup Gitolite. This will be inserted in to the @file{keydir} directory
23905 within the gitolite-admin repository.
23907 To specify the SSH key as a string, use the @code{plain-file} function.
23910 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23916 @deftp {Data Type} gitolite-rc-file
23917 Data type representing the Gitolite RC file.
23920 @item @code{umask} (default: @code{#o0077})
23921 This controls the permissions Gitolite sets on the repositories and their
23924 A value like @code{#o0027} will give read access to the group used by Gitolite
23925 (by default: @code{git}). This is necessary when using Gitolite with software
23926 like cgit or gitweb.
23928 @item @code{git-config-keys} (default: @code{""})
23929 Gitolite allows you to set git config values using the "config" keyword. This
23930 setting allows control over the config keys to accept.
23932 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23933 Set the role names allowed to be used by users running the perms command.
23935 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23936 This setting controls the commands and features to enable within Gitolite.
23942 @node Game Services
23943 @subsection Game Services
23945 @subsubheading The Battle for Wesnoth Service
23947 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23948 based tactical strategy game, with several single player campaigns, and
23949 multiplayer games (both networked and local).
23951 @defvar {Scheme Variable} wesnothd-service-type
23952 Service type for the wesnothd service. Its value must be a
23953 @code{wesnothd-configuration} object. To run wesnothd in the default
23954 configuration, instantiate it as:
23957 (service wesnothd-service-type)
23961 @deftp {Data Type} wesnothd-configuration
23962 Data type representing the configuration of @command{wesnothd}.
23965 @item @code{package} (default: @code{wesnoth-server})
23966 The wesnoth server package to use.
23968 @item @code{port} (default: @code{15000})
23969 The port to bind the server to.
23973 @node Miscellaneous Services
23974 @subsection Miscellaneous Services
23976 @cindex fingerprint
23977 @subsubheading Fingerprint Service
23979 The @code{(gnu services authentication)} module provides a DBus service to
23980 read and identify fingerprints via a fingerprint sensor.
23982 @defvr {Scheme Variable} fprintd-service-type
23983 The service type for @command{fprintd}, which provides the fingerprint
23984 reading capability.
23987 (service fprintd-service-type)
23992 @subsubheading System Control Service
23994 The @code{(gnu services sysctl)} provides a service to configure kernel
23995 parameters at boot.
23997 @defvr {Scheme Variable} sysctl-service-type
23998 The service type for @command{sysctl}, which modifies kernel parameters
23999 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
24003 (service sysctl-service-type
24004 (sysctl-configuration
24005 (settings '(("net.ipv4.ip_forward" . "1")))))
24009 @deftp {Data Type} sysctl-configuration
24010 The data type representing the configuration of @command{sysctl}.
24013 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
24014 The @command{sysctl} executable to use.
24016 @item @code{settings} (default: @code{'()})
24017 An association list specifies kernel parameters and their values.
24022 @subsubheading PC/SC Smart Card Daemon Service
24024 The @code{(gnu services security-token)} module provides the following service
24025 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
24026 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
24027 manager that coordinates communications with smart card readers, smart cards
24028 and cryptographic tokens that are connected to the system.
24030 @defvr {Scheme Variable} pcscd-service-type
24031 Service type for the @command{pcscd} service. Its value must be a
24032 @code{pcscd-configuration} object. To run pcscd in the default
24033 configuration, instantiate it as:
24036 (service pcscd-service-type)
24040 @deftp {Data Type} pcscd-configuration
24041 The data type representing the configuration of @command{pcscd}.
24044 @item @code{pcsc-lite} (default: @code{pcsc-lite})
24045 The pcsc-lite package that provides pcscd.
24046 @item @code{usb-drivers} (default: @code{(list ccid)})
24047 List of packages that provide USB drivers to pcscd. Drivers are expected to be
24048 under @file{pcsc/drivers} in the store directory of the package.
24053 @subsubheading Lirc Service
24055 The @code{(gnu services lirc)} module provides the following service.
24057 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
24058 [#:device #f] [#:driver #f] [#:config-file #f] @
24059 [#:extra-options '()]
24060 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
24061 decodes infrared signals from remote controls.
24063 Optionally, @var{device}, @var{driver} and @var{config-file}
24064 (configuration file name) may be specified. See @command{lircd} manual
24067 Finally, @var{extra-options} is a list of additional command-line options
24068 passed to @command{lircd}.
24072 @subsubheading Spice Service
24074 The @code{(gnu services spice)} module provides the following service.
24076 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
24077 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
24078 that enables sharing the clipboard with a vm and setting the guest display
24079 resolution when the graphical console window resizes.
24082 @cindex inputattach
24083 @subsubheading inputattach Service
24085 @cindex tablet input, for Xorg
24086 @cindex touchscreen input, for Xorg
24087 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
24088 use input devices such as Wacom tablets, touchscreens, or joysticks with the
24089 Xorg display server.
24091 @deffn {Scheme Variable} inputattach-service-type
24092 Type of a service that runs @command{inputattach} on a device and
24093 dispatches events from it.
24096 @deftp {Data Type} inputattach-configuration
24098 @item @code{device-type} (default: @code{"wacom"})
24099 The type of device to connect to. Run @command{inputattach --help}, from the
24100 @code{inputattach} package, to see the list of supported device types.
24102 @item @code{device} (default: @code{"/dev/ttyS0"})
24103 The device file to connect to the device.
24105 @item @code{log-file} (default: @code{#f})
24106 If true, this must be the name of a file to log messages to.
24110 @subsection Dictionary Services
24112 The @code{(gnu services dict)} module provides the following service:
24114 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
24115 Return a service that runs the @command{dicod} daemon, an implementation
24116 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
24118 The optional @var{config} argument specifies the configuration for
24119 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
24120 default it serves the GNU Collaborative International Dictonary of English.
24122 You can add @command{open localhost} to your @file{~/.dico} file to make
24123 @code{localhost} the default server for @command{dico} client
24124 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
24127 @deftp {Data Type} dicod-configuration
24128 Data type representing the configuration of dicod.
24131 @item @code{dico} (default: @var{dico})
24132 Package object of the GNU Dico dictionary server.
24134 @item @code{interfaces} (default: @var{'("localhost")})
24135 This is the list of IP addresses and ports and possibly socket file
24136 names to listen to (@pxref{Server Settings, @code{listen} directive,,
24137 dico, GNU Dico Manual}).
24139 @item @code{handlers} (default: @var{'()})
24140 List of @code{<dicod-handler>} objects denoting handlers (module instances).
24142 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
24143 List of @code{<dicod-database>} objects denoting dictionaries to be served.
24147 @deftp {Data Type} dicod-handler
24148 Data type representing a dictionary handler (module instance).
24152 Name of the handler (module instance).
24154 @item @code{module} (default: @var{#f})
24155 Name of the dicod module of the handler (instance). If it is @code{#f},
24156 the module has the same name as the handler.
24157 (@pxref{Modules,,, dico, GNU Dico Manual}).
24159 @item @code{options}
24160 List of strings or gexps representing the arguments for the module handler
24164 @deftp {Data Type} dicod-database
24165 Data type representing a dictionary database.
24169 Name of the database, will be used in DICT commands.
24171 @item @code{handler}
24172 Name of the dicod handler (module instance) used by this database
24173 (@pxref{Handlers,,, dico, GNU Dico Manual}).
24175 @item @code{complex?} (default: @var{#f})
24176 Whether the database configuration complex. The complex configuration
24177 will need a corresponding @code{<dicod-handler>} object, otherwise not.
24179 @item @code{options}
24180 List of strings or gexps representing the arguments for the database
24181 (@pxref{Databases,,, dico, GNU Dico Manual}).
24185 @defvr {Scheme Variable} %dicod-database:gcide
24186 A @code{<dicod-database>} object serving the GNU Collaborative International
24187 Dictionary of English using the @code{gcide} package.
24190 The following is an example @code{dicod-service} configuration.
24193 (dicod-service #:config
24194 (dicod-configuration
24195 (handlers (list (dicod-handler
24199 (list #~(string-append "dbdir=" #$wordnet))))))
24200 (databases (list (dicod-database
24203 (handler "wordnet")
24204 (options '("database=wn")))
24205 %dicod-database:gcide))))
24209 @subsubheading Docker Service
24211 The @code{(gnu services docker)} module provides the following services.
24213 @defvr {Scheme Variable} docker-service-type
24215 This is the type of the service that runs @url{https://www.docker.com,Docker},
24216 a daemon that can execute application bundles (sometimes referred to as
24217 ``containers'') in isolated environments.
24221 @deftp {Data Type} docker-configuration
24222 This is the data type representing the configuration of Docker and Containerd.
24226 @item @code{package} (default: @code{docker})
24227 The Docker package to use.
24229 @item @code{containerd} (default: @var{containerd})
24230 The Containerd package to use.
24236 @subsubheading Auditd Service
24238 The @code{(gnu services auditd)} module provides the following service.
24240 @defvr {Scheme Variable} auditd-service-type
24242 This is the type of the service that runs
24243 @url{https://people.redhat.com/sgrubb/audit/,auditd},
24244 a daemon that tracks security-relevant information on your system.
24246 Examples of things that can be tracked:
24256 Failed login attempts
24263 @command{auditctl} from the @code{audit} package can be used in order
24264 to add or remove events to be tracked (until the next reboot).
24265 In order to permanently track events, put the command line arguments
24266 of auditctl into @file{/etc/audit/audit.rules}.
24267 @command{aureport} from the @code{audit} package can be used in order
24268 to view a report of all recorded events.
24269 The audit daemon usually logs into the directory @file{/var/log/audit}.
24273 @deftp {Data Type} auditd-configuration
24274 This is the data type representing the configuration of auditd.
24278 @item @code{audit} (default: @code{audit})
24279 The audit package to use.
24284 @defvr {Scheme Variable} singularity-service-type
24285 This is the type of the service that allows you to run
24286 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
24287 create and run application bundles (aka. ``containers''). The value for this
24288 service is the Singularity package to use.
24290 The service does not install a daemon; instead, it installs helper programs as
24291 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
24292 @command{singularity run} and similar commands.
24296 @subsubheading Nix service
24298 The @code{(gnu services nix)} module provides the following service.
24300 @defvr {Scheme Variable} nix-service-type
24302 This is the type of the service that runs build daemon of the
24303 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
24307 (use-modules (gnu))
24308 (use-service-modules nix)
24309 (use-package-modules package-management)
24313 (packages (append (list nix)
24316 (services (append (list (service nix-service-type))
24320 After @command{guix system reconfigure} configure Nix for your user:
24323 @item Add a Nix channel and update it. See
24324 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
24326 @item Create a symlink to your profile and activate Nix profile:
24330 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
24331 $ source /run/current-system/profile/etc/profile.d/nix.sh
24336 @node Setuid Programs
24337 @section Setuid Programs
24339 @cindex setuid programs
24340 Some programs need to run with ``root'' privileges, even when they are
24341 launched by unprivileged users. A notorious example is the
24342 @command{passwd} program, which users can run to change their
24343 password, and which needs to access the @file{/etc/passwd} and
24344 @file{/etc/shadow} files---something normally restricted to root, for
24345 obvious security reasons. To address that, these executables are
24346 @dfn{setuid-root}, meaning that they always run with root privileges
24347 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
24348 for more info about the setuid mechanism.)
24350 The store itself @emph{cannot} contain setuid programs: that would be a
24351 security issue since any user on the system can write derivations that
24352 populate the store (@pxref{The Store}). Thus, a different mechanism is
24353 used: instead of changing the setuid bit directly on files that are in
24354 the store, we let the system administrator @emph{declare} which programs
24355 should be setuid root.
24357 The @code{setuid-programs} field of an @code{operating-system}
24358 declaration contains a list of G-expressions denoting the names of
24359 programs to be setuid-root (@pxref{Using the Configuration System}).
24360 For instance, the @command{passwd} program, which is part of the Shadow
24361 package, can be designated by this G-expression (@pxref{G-Expressions}):
24364 #~(string-append #$shadow "/bin/passwd")
24367 A default set of setuid programs is defined by the
24368 @code{%setuid-programs} variable of the @code{(gnu system)} module.
24370 @defvr {Scheme Variable} %setuid-programs
24371 A list of G-expressions denoting common programs that are setuid-root.
24373 The list includes commands such as @command{passwd}, @command{ping},
24374 @command{su}, and @command{sudo}.
24377 Under the hood, the actual setuid programs are created in the
24378 @file{/run/setuid-programs} directory at system activation time. The
24379 files in this directory refer to the ``real'' binaries, which are in the
24382 @node X.509 Certificates
24383 @section X.509 Certificates
24385 @cindex HTTPS, certificates
24386 @cindex X.509 certificates
24388 Web servers available over HTTPS (that is, HTTP over the transport-layer
24389 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
24390 that the client can then use to @emph{authenticate} the server. To do
24391 that, clients verify that the server's certificate is signed by a
24392 so-called @dfn{certificate authority} (CA). But to verify the CA's
24393 signature, clients must have first acquired the CA's certificate.
24395 Web browsers such as GNU@tie{}IceCat include their own set of CA
24396 certificates, such that they are able to verify CA signatures
24399 However, most other programs that can talk HTTPS---@command{wget},
24400 @command{git}, @command{w3m}, etc.---need to be told where CA
24401 certificates can be found.
24403 @cindex @code{nss-certs}
24404 In Guix, this is done by adding a package that provides certificates
24405 to the @code{packages} field of the @code{operating-system} declaration
24406 (@pxref{operating-system Reference}). Guix includes one such package,
24407 @code{nss-certs}, which is a set of CA certificates provided as part of
24408 Mozilla's Network Security Services.
24410 Note that it is @emph{not} part of @code{%base-packages}, so you need to
24411 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
24412 most applications and libraries look for certificates by default, points
24413 to the certificates installed globally.
24415 Unprivileged users, including users of Guix on a foreign distro,
24416 can also install their own certificate package in
24417 their profile. A number of environment variables need to be defined so
24418 that applications and libraries know where to find them. Namely, the
24419 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
24420 variables. Some applications add their own environment variables; for
24421 instance, the Git version control system honors the certificate bundle
24422 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
24423 would typically run something like:
24426 $ guix install nss-certs
24427 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
24428 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
24429 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
24432 As another example, R requires the @code{CURL_CA_BUNDLE} environment
24433 variable to point to a certificate bundle, so you would have to run
24434 something like this:
24437 $ guix install nss-certs
24438 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
24441 For other applications you may want to look up the required environment
24442 variable in the relevant documentation.
24445 @node Name Service Switch
24446 @section Name Service Switch
24448 @cindex name service switch
24450 The @code{(gnu system nss)} module provides bindings to the
24451 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
24452 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
24453 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
24454 extended with new ``name'' lookup methods for system databases, which
24455 includes host names, service names, user accounts, and more (@pxref{Name
24456 Service Switch, System Databases and Name Service Switch,, libc, The GNU
24457 C Library Reference Manual}).
24459 The NSS configuration specifies, for each system database, which lookup
24460 method is to be used, and how the various methods are chained
24461 together---for instance, under which circumstances NSS should try the
24462 next method in the list. The NSS configuration is given in the
24463 @code{name-service-switch} field of @code{operating-system} declarations
24464 (@pxref{operating-system Reference, @code{name-service-switch}}).
24467 @cindex .local, host name lookup
24468 As an example, the declaration below configures the NSS to use the
24469 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
24470 back-end}, which supports host name lookups over multicast DNS (mDNS)
24471 for host names ending in @code{.local}:
24474 (name-service-switch
24475 (hosts (list %files ;first, check /etc/hosts
24477 ;; If the above did not succeed, try
24478 ;; with 'mdns_minimal'.
24480 (name "mdns_minimal")
24482 ;; 'mdns_minimal' is authoritative for
24483 ;; '.local'. When it returns "not found",
24484 ;; no need to try the next methods.
24485 (reaction (lookup-specification
24486 (not-found => return))))
24488 ;; Then fall back to DNS.
24492 ;; Finally, try with the "full" 'mdns'.
24497 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
24498 contains this configuration, so you will not have to type it if all you
24499 want is to have @code{.local} host lookup working.
24501 Note that, in this case, in addition to setting the
24502 @code{name-service-switch} of the @code{operating-system} declaration,
24503 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
24504 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
24505 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
24506 to the name service cache daemon (@pxref{Base Services,
24507 @code{nscd-service}}).
24509 For convenience, the following variables provide typical NSS
24512 @defvr {Scheme Variable} %default-nss
24513 This is the default name service switch configuration, a
24514 @code{name-service-switch} object.
24517 @defvr {Scheme Variable} %mdns-host-lookup-nss
24518 This is the name service switch configuration with support for host name
24519 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
24522 The reference for name service switch configuration is given below. It
24523 is a direct mapping of the configuration file format of the C library , so
24524 please refer to the C library manual for more information (@pxref{NSS
24525 Configuration File,,, libc, The GNU C Library Reference Manual}).
24526 Compared to the configuration file format of libc NSS, it has the advantage
24527 not only of adding this warm parenthetic feel that we like, but also
24528 static checks: you will know about syntax errors and typos as soon as you
24529 run @command{guix system}.
24531 @deftp {Data Type} name-service-switch
24533 This is the data type representation the configuration of libc's name
24534 service switch (NSS). Each field below represents one of the supported
24551 The system databases handled by the NSS. Each of these fields must be a
24552 list of @code{<name-service>} objects (see below).
24556 @deftp {Data Type} name-service
24558 This is the data type representing an actual name service and the
24559 associated lookup action.
24563 A string denoting the name service (@pxref{Services in the NSS
24564 configuration,,, libc, The GNU C Library Reference Manual}).
24566 Note that name services listed here must be visible to nscd. This is
24567 achieved by passing the @code{#:name-services} argument to
24568 @code{nscd-service} the list of packages providing the needed name
24569 services (@pxref{Base Services, @code{nscd-service}}).
24572 An action specified using the @code{lookup-specification} macro
24573 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
24574 Reference Manual}). For example:
24577 (lookup-specification (unavailable => continue)
24578 (success => return))
24583 @node Initial RAM Disk
24584 @section Initial RAM Disk
24587 @cindex initial RAM disk
24588 For bootstrapping purposes, the Linux-Libre kernel is passed an
24589 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
24590 root file system as well as an initialization script. The latter is
24591 responsible for mounting the real root file system, and for loading any
24592 kernel modules that may be needed to achieve that.
24594 The @code{initrd-modules} field of an @code{operating-system}
24595 declaration allows you to specify Linux-libre kernel modules that must
24596 be available in the initrd. In particular, this is where you would list
24597 modules needed to actually drive the hard disk where your root partition
24598 is---although the default value of @code{initrd-modules} should cover
24599 most use cases. For example, assuming you need the @code{megaraid_sas}
24600 module in addition to the default modules to be able to access your root
24601 file system, you would write:
24606 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
24609 @defvr {Scheme Variable} %base-initrd-modules
24610 This is the list of kernel modules included in the initrd by default.
24613 Furthermore, if you need lower-level customization, the @code{initrd}
24614 field of an @code{operating-system} declaration allows
24615 you to specify which initrd you would like to use. The @code{(gnu
24616 system linux-initrd)} module provides three ways to build an initrd: the
24617 high-level @code{base-initrd} procedure and the low-level
24618 @code{raw-initrd} and @code{expression->initrd} procedures.
24620 The @code{base-initrd} procedure is intended to cover most common uses.
24621 For example, if you want to add a bunch of kernel modules to be loaded
24622 at boot time, you can define the @code{initrd} field of the operating
24623 system declaration like this:
24626 (initrd (lambda (file-systems . rest)
24627 ;; Create a standard initrd but set up networking
24628 ;; with the parameters QEMU expects by default.
24629 (apply base-initrd file-systems
24630 #:qemu-networking? #t
24634 The @code{base-initrd} procedure also handles common use cases that
24635 involves using the system as a QEMU guest, or as a ``live'' system with
24636 volatile root file system.
24638 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
24639 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
24640 such as trying to guess which kernel modules and packages should be included
24641 to the initrd. An example use of @code{raw-initrd} is when a user has
24642 a custom Linux kernel configuration and default kernel modules included by
24643 @code{base-initrd} are not available.
24645 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
24646 honors several options passed on the Linux kernel command line
24647 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
24648 @code{-append} option of QEMU), notably:
24651 @item --load=@var{boot}
24652 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
24653 program, once it has mounted the root file system.
24655 Guix uses this option to yield control to a boot program that runs the
24656 service activation programs and then spawns the GNU@tie{}Shepherd, the
24657 initialization system.
24659 @item --root=@var{root}
24660 Mount @var{root} as the root file system. @var{root} can be a
24661 device name like @code{/dev/sda1}, a file system label, or a file system
24664 @item --system=@var{system}
24665 Have @file{/run/booted-system} and @file{/run/current-system} point to
24668 @item modprobe.blacklist=@var{modules}@dots{}
24669 @cindex module, black-listing
24670 @cindex black list, of kernel modules
24671 Instruct the initial RAM disk as well as the @command{modprobe} command
24672 (from the kmod package) to refuse to load @var{modules}. @var{modules}
24673 must be a comma-separated list of module names---e.g.,
24674 @code{usbkbd,9pnet}.
24677 Start a read-eval-print loop (REPL) from the initial RAM disk before it
24678 tries to load kernel modules and to mount the root file system. Our
24679 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
24680 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
24681 Manual}, for more information on Guile's REPL.
24685 Now that you know all the features that initial RAM disks produced by
24686 @code{base-initrd} and @code{raw-initrd} provide,
24687 here is how to use it and customize it further.
24690 @cindex initial RAM disk
24691 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
24692 [#:linux-modules '()] [#:mapped-devices '()] @
24693 [#:keyboard-layout #f] @
24694 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
24695 Return a derivation that builds a raw initrd. @var{file-systems} is
24696 a list of file systems to be mounted by the initrd, possibly in addition to
24697 the root file system specified on the kernel command line via @code{--root}.
24698 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
24699 @var{mapped-devices} is a list of device mappings to realize before
24700 @var{file-systems} are mounted (@pxref{Mapped Devices}).
24701 @var{helper-packages} is a list of packages to be copied in the initrd. It may
24702 include @code{e2fsck/static} or other packages needed by the initrd to check
24703 the root file system.
24705 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24706 the desired console keyboard layout. This is done before @var{mapped-devices}
24707 are set up and before @var{file-systems} are mounted such that, should the
24708 user need to enter a passphrase or use the REPL, this happens using the
24709 intended keyboard layout.
24711 When @var{qemu-networking?} is true, set up networking with the standard QEMU
24712 parameters. When @var{virtio?} is true, load additional modules so that the
24713 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
24715 When @var{volatile-root?} is true, the root file system is writable but any changes
24719 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
24720 [#:mapped-devices '()] [#:keyboard-layout #f] @
24721 [#:qemu-networking? #f] [#:volatile-root? #f] @
24722 [#:linux-modules '()]
24723 Return as a file-like object a generic initrd, with kernel
24724 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
24725 mounted by the initrd, possibly in addition to the root file system specified
24726 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
24727 mappings to realize before @var{file-systems} are mounted.
24729 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24730 the desired console keyboard layout. This is done before @var{mapped-devices}
24731 are set up and before @var{file-systems} are mounted such that, should the
24732 user need to enter a passphrase or use the REPL, this happens using the
24733 intended keyboard layout.
24735 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
24737 The initrd is automatically populated with all the kernel modules necessary
24738 for @var{file-systems} and for the given options. Additional kernel
24739 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
24740 loaded at boot time in the order in which they appear.
24743 Needless to say, the initrds we produce and use embed a
24744 statically-linked Guile, and the initialization program is a Guile
24745 program. That gives a lot of flexibility. The
24746 @code{expression->initrd} procedure builds such an initrd, given the
24747 program to run in that initrd.
24749 @deffn {Scheme Procedure} expression->initrd @var{exp} @
24750 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
24751 Return as a file-like object a Linux initrd (a gzipped cpio archive)
24752 containing @var{guile} and that evaluates @var{exp}, a G-expression,
24753 upon booting. All the derivations referenced by @var{exp} are
24754 automatically copied to the initrd.
24757 @node Bootloader Configuration
24758 @section Bootloader Configuration
24761 @cindex boot loader
24763 The operating system supports multiple bootloaders. The bootloader is
24764 configured using @code{bootloader-configuration} declaration. All the
24765 fields of this structure are bootloader agnostic except for one field,
24766 @code{bootloader} that indicates the bootloader to be configured and
24769 Some of the bootloaders do not honor every field of
24770 @code{bootloader-configuration}. For instance, the extlinux
24771 bootloader does not support themes and thus ignores the @code{theme}
24774 @deftp {Data Type} bootloader-configuration
24775 The type of a bootloader configuration declaration.
24779 @item @code{bootloader}
24780 @cindex EFI, bootloader
24781 @cindex UEFI, bootloader
24782 @cindex BIOS, bootloader
24783 The bootloader to use, as a @code{bootloader} object. For now
24784 @code{grub-bootloader}, @code{grub-efi-bootloader},
24785 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24787 @vindex grub-efi-bootloader
24788 @code{grub-efi-bootloader} allows to boot on modern systems using the
24789 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24790 use if the installation image contains a @file{/sys/firmware/efi} directory
24791 when you boot it on your system.
24793 @vindex grub-bootloader
24794 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24795 in ``legacy'' BIOS mode.
24797 @cindex ARM, bootloaders
24798 @cindex AArch64, bootloaders
24799 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24800 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24801 of bootloaders for a wide range of ARM and AArch64 systems, using the
24802 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24804 @item @code{target}
24805 This is a string denoting the target onto which to install the
24808 The interpretation depends on the bootloader in question. For
24809 @code{grub-bootloader}, for example, it should be a device name understood by
24810 the bootloader @command{installer} command, such as @code{/dev/sda} or
24811 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24812 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24813 system, usually @file{/boot/efi}.
24815 @item @code{menu-entries} (default: @code{()})
24816 A possibly empty list of @code{menu-entry} objects (see below), denoting
24817 entries to appear in the bootloader menu, in addition to the current
24818 system entry and the entry pointing to previous system generations.
24820 @item @code{default-entry} (default: @code{0})
24821 The index of the default boot menu entry. Index 0 is for the entry of the
24824 @item @code{timeout} (default: @code{5})
24825 The number of seconds to wait for keyboard input before booting. Set to
24826 0 to boot immediately, and to -1 to wait indefinitely.
24828 @cindex keyboard layout, for the bootloader
24829 @item @code{keyboard-layout} (default: @code{#f})
24830 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24831 layout, usually US@tie{}English (``qwerty'').
24833 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24837 This option is currently ignored by bootloaders other than @code{grub} and
24841 @item @code{theme} (default: @var{#f})
24842 The bootloader theme object describing the theme to use. If no theme
24843 is provided, some bootloaders might use a default theme, that's true
24846 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
24847 The output terminals used for the bootloader boot menu, as a list of
24848 symbols. GRUB accepts the values: @code{console}, @code{serial},
24849 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24850 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24851 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24852 configuration,,, grub,GNU GRUB manual}).
24854 @item @code{terminal-inputs} (default: @code{'()})
24855 The input terminals used for the bootloader boot menu, as a list of
24856 symbols. For GRUB, the default is the native platform terminal as
24857 determined at run-time. GRUB accepts the values: @code{console},
24858 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24859 @code{usb_keyboard}. This field corresponds to the GRUB variable
24860 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24863 @item @code{serial-unit} (default: @code{#f})
24864 The serial unit used by the bootloader, as an integer from 0 to 3.
24865 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24866 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24868 @item @code{serial-speed} (default: @code{#f})
24869 The speed of the serial interface, as an integer. For GRUB, the
24870 default value is chosen at run-time; currently GRUB chooses
24871 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24878 Should you want to list additional boot menu entries @i{via} the
24879 @code{menu-entries} field above, you will need to create them with the
24880 @code{menu-entry} form. For example, imagine you want to be able to
24881 boot another distro (hard to imagine!), you can define a menu entry
24886 (label "The Other Distro")
24887 (linux "/boot/old/vmlinux-2.6.32")
24888 (linux-arguments '("root=/dev/sda2"))
24889 (initrd "/boot/old/initrd"))
24894 @deftp {Data Type} menu-entry
24895 The type of an entry in the bootloader menu.
24900 The label to show in the menu---e.g., @code{"GNU"}.
24903 The Linux kernel image to boot, for example:
24906 (file-append linux-libre "/bzImage")
24909 For GRUB, it is also possible to specify a device explicitly in the
24910 file path using GRUB's device naming convention (@pxref{Naming
24911 convention,,, grub, GNU GRUB manual}), for example:
24914 "(hd0,msdos1)/boot/vmlinuz"
24917 If the device is specified explicitly as above, then the @code{device}
24918 field is ignored entirely.
24920 @item @code{linux-arguments} (default: @code{()})
24921 The list of extra Linux kernel command-line arguments---e.g.,
24922 @code{("console=ttyS0")}.
24924 @item @code{initrd}
24925 A G-Expression or string denoting the file name of the initial RAM disk
24926 to use (@pxref{G-Expressions}).
24927 @item @code{device} (default: @code{#f})
24928 The device where the kernel and initrd are to be found---i.e., for GRUB,
24929 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24931 This may be a file system label (a string), a file system UUID (a
24932 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24933 the bootloader will search the device containing the file specified by
24934 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24935 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24940 @c FIXME: Write documentation once it's stable.
24941 For now only GRUB has theme support. GRUB themes are created using
24942 the @code{grub-theme} form, which is not documented yet.
24944 @defvr {Scheme Variable} %default-theme
24945 This is the default GRUB theme used by the operating system if no
24946 @code{theme} field is specified in @code{bootloader-configuration}
24949 It comes with a fancy background image displaying the GNU and Guix
24954 @node Invoking guix system
24955 @section Invoking @code{guix system}
24957 Once you have written an operating system declaration as seen in the
24958 previous section, it can be @dfn{instantiated} using the @command{guix
24959 system} command. The synopsis is:
24962 guix system @var{options}@dots{} @var{action} @var{file}
24965 @var{file} must be the name of a file containing an
24966 @code{operating-system} declaration. @var{action} specifies how the
24967 operating system is instantiated. Currently the following values are
24972 Display available service type definitions that match the given regular
24973 expressions, sorted by relevance:
24976 $ guix system search console font
24977 name: console-fonts
24978 location: gnu/services/base.scm:729:2
24979 extends: shepherd-root
24980 description: Install the given fonts on the specified ttys (fonts are
24981 + per virtual console on GNU/Linux). The value of this service is a list
24982 + of tty/font pairs like:
24984 + '(("tty1" . "LatGrkCyr-8x16"))
24988 location: gnu/services/base.scm:1048:2
24989 extends: shepherd-root
24990 description: Provide console login using the `mingetty' program.
24994 location: gnu/services/base.scm:775:2
24996 description: Provide a console log-in service as specified by its
24997 + configuration value, a `login-configuration' object.
25003 As for @command{guix package --search}, the result is written in
25004 @code{recutils} format, which makes it easy to filter the output
25005 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
25008 Build the operating system described in @var{file}, activate it, and
25009 switch to it@footnote{This action (and the related actions
25010 @code{switch-generation} and @code{roll-back}) are usable only on
25011 systems already running Guix System.}.
25013 This effects all the configuration specified in @var{file}: user
25014 accounts, system services, global package list, setuid programs, etc.
25015 The command starts system services specified in @var{file} that are not
25016 currently running; if a service is currently running this command will
25017 arrange for it to be upgraded the next time it is stopped (e.g.@: by
25018 @code{herd stop X} or @code{herd restart X}).
25020 This command creates a new generation whose number is one greater than
25021 the current generation (as reported by @command{guix system
25022 list-generations}). If that generation already exists, it will be
25023 overwritten. This behavior mirrors that of @command{guix package}
25024 (@pxref{Invoking guix package}).
25026 It also adds a bootloader menu entry for the new OS configuration,
25027 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
25028 entries for older configurations to a submenu, allowing you to choose
25029 an older system generation at boot time should you need it.
25032 @c The paragraph below refers to the problem discussed at
25033 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
25034 It is highly recommended to run @command{guix pull} once before you run
25035 @command{guix system reconfigure} for the first time (@pxref{Invoking
25036 guix pull}). Failing to do that you would see an older version of Guix
25037 once @command{reconfigure} has completed.
25040 @item switch-generation
25041 @cindex generations
25042 Switch to an existing system generation. This action atomically
25043 switches the system profile to the specified system generation. It
25044 also rearranges the system's existing bootloader menu entries. It
25045 makes the menu entry for the specified system generation the default,
25046 and it moves the entries for the other generatiors to a submenu, if
25047 supported by the bootloader being used. The next time the system
25048 boots, it will use the specified system generation.
25050 The bootloader itself is not being reinstalled when using this
25051 command. Thus, the installed bootloader is used with an updated
25052 configuration file.
25054 The target generation can be specified explicitly by its generation
25055 number. For example, the following invocation would switch to system
25059 guix system switch-generation 7
25062 The target generation can also be specified relative to the current
25063 generation with the form @code{+N} or @code{-N}, where @code{+3} means
25064 ``3 generations ahead of the current generation,'' and @code{-1} means
25065 ``1 generation prior to the current generation.'' When specifying a
25066 negative value such as @code{-1}, you must precede it with @code{--} to
25067 prevent it from being parsed as an option. For example:
25070 guix system switch-generation -- -1
25073 Currently, the effect of invoking this action is @emph{only} to switch
25074 the system profile to an existing generation and rearrange the
25075 bootloader menu entries. To actually start using the target system
25076 generation, you must reboot after running this action. In the future,
25077 it will be updated to do the same things as @command{reconfigure},
25078 like activating and deactivating services.
25080 This action will fail if the specified generation does not exist.
25083 @cindex rolling back
25084 Switch to the preceding system generation. The next time the system
25085 boots, it will use the preceding system generation. This is the inverse
25086 of @command{reconfigure}, and it is exactly the same as invoking
25087 @command{switch-generation} with an argument of @code{-1}.
25089 Currently, as with @command{switch-generation}, you must reboot after
25090 running this action to actually start using the preceding system
25093 @item delete-generations
25094 @cindex deleting system generations
25095 @cindex saving space
25096 Delete system generations, making them candidates for garbage collection
25097 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
25100 This works in the same way as @command{guix package --delete-generations}
25101 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
25102 arguments, all system generations but the current one are deleted:
25105 guix system delete-generations
25108 You can also select the generations you want to delete. The example below
25109 deletes all the system generations that are more than two month old:
25112 guix system delete-generations 2m
25115 Running this command automatically reinstalls the bootloader with an updated
25116 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
25117 longer lists the generations that have been deleted.
25120 Build the derivation of the operating system, which includes all the
25121 configuration files and programs needed to boot and run the system.
25122 This action does not actually install anything.
25125 Populate the given directory with all the files necessary to run the
25126 operating system specified in @var{file}. This is useful for first-time
25127 installations of Guix System. For instance:
25130 guix system init my-os-config.scm /mnt
25133 copies to @file{/mnt} all the store items required by the configuration
25134 specified in @file{my-os-config.scm}. This includes configuration
25135 files, packages, and so on. It also creates other essential files
25136 needed for the system to operate correctly---e.g., the @file{/etc},
25137 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
25139 This command also installs bootloader on the target specified in
25140 @file{my-os-config}, unless the @option{--no-bootloader} option was
25144 @cindex virtual machine
25146 @anchor{guix system vm}
25147 Build a virtual machine that contains the operating system declared in
25148 @var{file}, and return a script to run that virtual machine (VM).
25151 The @code{vm} action and others below
25152 can use KVM support in the Linux-libre kernel. Specifically, if the
25153 machine has hardware virtualization support, the corresponding
25154 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
25155 must exist and be readable and writable by the user and by the
25156 build users of the daemon (@pxref{Build Environment Setup}).
25159 Arguments given to the script are passed to QEMU as in the example
25160 below, which enables networking and requests 1@tie{}GiB of RAM for the
25164 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
25167 The VM shares its store with the host system.
25169 Additional file systems can be shared between the host and the VM using
25170 the @code{--share} and @code{--expose} command-line options: the former
25171 specifies a directory to be shared with write access, while the latter
25172 provides read-only access to the shared directory.
25174 The example below creates a VM in which the user's home directory is
25175 accessible read-only, and where the @file{/exchange} directory is a
25176 read-write mapping of @file{$HOME/tmp} on the host:
25179 guix system vm my-config.scm \
25180 --expose=$HOME --share=$HOME/tmp=/exchange
25183 On GNU/Linux, the default is to boot directly to the kernel; this has
25184 the advantage of requiring only a very tiny root disk image since the
25185 store of the host can then be mounted.
25187 The @code{--full-boot} option forces a complete boot sequence, starting
25188 with the bootloader. This requires more disk space since a root image
25189 containing at least the kernel, initrd, and bootloader data files must
25190 be created. The @code{--image-size} option can be used to specify the
25193 @cindex System images, creation in various formats
25194 @cindex Creating system images in various formats
25197 @itemx docker-image
25198 Return a virtual machine, disk image, or Docker image of the operating
25199 system declared in @var{file} that stands alone. By default,
25200 @command{guix system} estimates the size of the image needed to store
25201 the system, but you can use the @option{--image-size} option to specify
25202 a value. Docker images are built to contain exactly what they need, so
25203 the @option{--image-size} option is ignored in the case of
25204 @code{docker-image}.
25206 You can specify the root file system type by using the
25207 @option{--file-system-type} option. It defaults to @code{ext4}.
25209 When using @code{vm-image}, the returned image is in qcow2 format, which
25210 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
25211 for more information on how to run the image in a virtual machine.
25213 When using @code{disk-image}, a raw disk image is produced; it can be
25214 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
25215 the device corresponding to a USB stick, one can copy the image to it
25216 using the following command:
25219 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
25222 When using @code{docker-image}, a Docker image is produced. Guix builds
25223 the image from scratch, not from a pre-existing Docker base image. As a
25224 result, it contains @emph{exactly} what you define in the operating
25225 system configuration file. You can then load the image and launch a
25226 Docker container using commands like the following:
25229 image_id="`docker load < guix-system-docker-image.tar.gz`"
25230 container_id="`docker create $image_id`"
25231 docker start $container_id
25234 This command starts a new Docker container from the specified image. It
25235 will boot the Guix system in the usual manner, which means it will
25236 start any services you have defined in the operating system
25237 configuration. You can get an interactive shell running in the container
25238 using @command{docker exec}:
25241 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
25244 Depending on what you run in the Docker container, it
25245 may be necessary to give the container additional permissions. For
25246 example, if you intend to build software using Guix inside of the Docker
25247 container, you may need to pass the @option{--privileged} option to
25248 @code{docker create}.
25251 Return a script to run the operating system declared in @var{file}
25252 within a container. Containers are a set of lightweight isolation
25253 mechanisms provided by the kernel Linux-libre. Containers are
25254 substantially less resource-demanding than full virtual machines since
25255 the kernel, shared objects, and other resources can be shared with the
25256 host system; this also means they provide thinner isolation.
25258 Currently, the script must be run as root in order to support more than
25259 a single user and group. The container shares its store with the host
25262 As with the @code{vm} action (@pxref{guix system vm}), additional file
25263 systems to be shared between the host and container can be specified
25264 using the @option{--share} and @option{--expose} options:
25267 guix system container my-config.scm \
25268 --expose=$HOME --share=$HOME/tmp=/exchange
25272 This option requires Linux-libre 3.19 or newer.
25277 @var{options} can contain any of the common build options (@pxref{Common
25278 Build Options}). In addition, @var{options} can contain one of the
25282 @item --expression=@var{expr}
25283 @itemx -e @var{expr}
25284 Consider the operating-system @var{expr} evaluates to.
25285 This is an alternative to specifying a file which evaluates to an
25287 This is used to generate the Guix system installer @pxref{Building the
25288 Installation Image}).
25290 @item --system=@var{system}
25291 @itemx -s @var{system}
25292 Attempt to build for @var{system} instead of the host system type.
25293 This works as per @command{guix build} (@pxref{Invoking guix build}).
25297 Return the derivation file name of the given operating system without
25300 @item --file-system-type=@var{type}
25301 @itemx -t @var{type}
25302 For the @code{disk-image} action, create a file system of the given
25303 @var{type} on the image.
25305 When this option is omitted, @command{guix system} uses @code{ext4}.
25307 @cindex ISO-9660 format
25308 @cindex CD image format
25309 @cindex DVD image format
25310 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
25311 for burning on CDs and DVDs.
25313 @item --image-size=@var{size}
25314 For the @code{vm-image} and @code{disk-image} actions, create an image
25315 of the given @var{size}. @var{size} may be a number of bytes, or it may
25316 include a unit as a suffix (@pxref{Block size, size specifications,,
25317 coreutils, GNU Coreutils}).
25319 When this option is omitted, @command{guix system} computes an estimate
25320 of the image size as a function of the size of the system declared in
25325 For the @code{container} action, allow containers to access the host network,
25326 that is, do not create a network namespace.
25328 @item --root=@var{file}
25329 @itemx -r @var{file}
25330 Make @var{file} a symlink to the result, and register it as a garbage
25333 @item --skip-checks
25334 Skip pre-installation safety checks.
25336 By default, @command{guix system init} and @command{guix system
25337 reconfigure} perform safety checks: they make sure the file systems that
25338 appear in the @code{operating-system} declaration actually exist
25339 (@pxref{File Systems}), and that any Linux kernel modules that may be
25340 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
25341 RAM Disk}). Passing this option skips these tests altogether.
25344 @cindex on-error strategy
25345 @cindex error strategy
25346 @item --on-error=@var{strategy}
25347 Apply @var{strategy} when an error occurs when reading @var{file}.
25348 @var{strategy} may be one of the following:
25351 @item nothing-special
25352 Report the error concisely and exit. This is the default strategy.
25355 Likewise, but also display a backtrace.
25358 Report the error and enter Guile's debugger. From there, you can run
25359 commands such as @code{,bt} to get a backtrace, @code{,locals} to
25360 display local variable values, and more generally inspect the state of the
25361 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
25362 a list of available debugging commands.
25366 Once you have built, configured, re-configured, and re-re-configured
25367 your Guix installation, you may find it useful to list the operating
25368 system generations available on disk---and that you can choose from the
25369 bootloader boot menu:
25373 @item list-generations
25374 List a summary of each generation of the operating system available on
25375 disk, in a human-readable way. This is similar to the
25376 @option{--list-generations} option of @command{guix package}
25377 (@pxref{Invoking guix package}).
25379 Optionally, one can specify a pattern, with the same syntax that is used
25380 in @command{guix package --list-generations}, to restrict the list of
25381 generations displayed. For instance, the following command displays
25382 generations that are up to 10 days old:
25385 $ guix system list-generations 10d
25390 The @command{guix system} command has even more to offer! The following
25391 sub-commands allow you to visualize how your system services relate to
25394 @anchor{system-extension-graph}
25397 @item extension-graph
25398 Emit in Dot/Graphviz format to standard output the @dfn{service
25399 extension graph} of the operating system defined in @var{file}
25400 (@pxref{Service Composition}, for more information on service
25406 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
25409 produces a PDF file showing the extension relations among services.
25411 @anchor{system-shepherd-graph}
25412 @item shepherd-graph
25413 Emit in Dot/Graphviz format to standard output the @dfn{dependency
25414 graph} of shepherd services of the operating system defined in
25415 @var{file}. @xref{Shepherd Services}, for more information and for an
25420 @node Invoking guix deploy
25421 @section Invoking @code{guix deploy}
25423 We've already seen @code{operating-system} declarations used to manage a
25424 machine's configuration locally. Suppose you need to configure multiple
25425 machines, though---perhaps you're managing a service on the web that's
25426 comprised of several servers. @command{guix deploy} enables you to use those
25427 same @code{operating-system} declarations to manage multiple remote hosts at
25428 once as a logical ``deployment''.
25431 The functionality described in this section is still under development
25432 and is subject to change. Get in touch with us on
25433 @email{guix-devel@@gnu.org}!
25437 guix deploy @var{file}
25440 Such an invocation will deploy the machines that the code within @var{file}
25441 evaluates to. As an example, @var{file} might contain a definition like this:
25444 ;; This is a Guix deployment of a "bare bones" setup, with
25445 ;; no X11 display server, to a machine with an SSH daemon
25446 ;; listening on localhost:2222. A configuration such as this
25447 ;; may be appropriate for virtual machine with ports
25448 ;; forwarded to the host's loopback interface.
25450 (use-service-modules networking ssh)
25451 (use-package-modules bootloaders)
25455 (host-name "gnu-deployed")
25456 (timezone "Etc/UTC")
25457 (bootloader (bootloader-configuration
25458 (bootloader grub-bootloader)
25459 (target "/dev/vda")
25460 (terminal-outputs '(console))))
25461 (file-systems (cons (file-system
25463 (device "/dev/vda1")
25465 %base-file-systems))
25467 (append (list (service dhcp-client-service-type)
25468 (service openssh-service-type
25469 (openssh-configuration
25470 (permit-root-login #t)
25471 (allow-empty-passwords? #t))))
25476 (environment managed-host-environment-type)
25477 (configuration (machine-ssh-configuration
25478 (host-name "localhost")
25479 (identity "./id_rsa")
25483 The file should evaluate to a list of @var{machine} objects. This example,
25484 upon being deployed, will create a new generation on the remote system
25485 realizing the @code{operating-system} declaration @var{%system}.
25486 @var{environment} and @var{configuration} specify how the machine should be
25487 provisioned---that is, how the computing resources should be created and
25488 managed. The above example does not create any resources, as a
25489 @code{'managed-host} is a machine that is already running the Guix system and
25490 available over the network. This is a particularly simple case; a more
25491 complex deployment may involve, for example, starting virtual machines through
25492 a Virtual Private Server (VPS) provider. In such a case, a different
25493 @var{environment} type would be used.
25495 @deftp {Data Type} machine
25496 This is the data type representing a single machine in a heterogeneous Guix
25500 @item @code{system}
25501 The object of the operating system configuration to deploy.
25503 @item @code{environment}
25504 An @code{environment-type} describing how the machine should be provisioned.
25505 At the moment, the only supported value is
25506 @code{managed-host-environment-type}.
25508 @item @code{configuration} (default: @code{#f})
25509 An object describing the configuration for the machine's @code{environment}.
25510 If the @code{environment} has a default configuration, @code{#f} maybe used.
25511 If @code{#f} is used for an environment with no default configuration,
25512 however, an error will be thrown.
25516 @deftp {Data Type} machine-ssh-configuration
25517 This is the data type representing the SSH client parameters for a machine
25518 with an @code{environment} of @code{managed-host-environment-type}.
25521 @item @code{host-name}
25522 @item @code{port} (default: @code{22})
25523 @item @code{user} (default: @code{"root"})
25524 @item @code{identity} (default: @code{#f})
25525 If specified, the path to the SSH private key to use to authenticate with the
25530 @node Running Guix in a VM
25531 @section Running Guix in a Virtual Machine
25533 @cindex virtual machine
25534 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
25536 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
25537 This image is a compressed image in QCOW format. You will first need to
25538 decompress with @command{xz -d}, and then you can pass it to an emulator such
25539 as QEMU (see below for details).
25541 This image boots the Xfce graphical environment and it contains some
25542 commonly-used tools. You can install more software in the image by running
25543 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
25544 also reconfigure the system based on its initial configuration file available
25545 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
25547 Instead of using this pre-built image, one can also build their own virtual
25548 machine image using @command{guix system vm-image} (@pxref{Invoking guix
25549 system}). The returned image is in qcow2 format, which the
25550 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
25553 If you built your own image, you must copy it out of the store
25554 (@pxref{The Store}) and give yourself permission to write to the copy
25555 before you can use it. When invoking QEMU, you must choose a system
25556 emulator that is suitable for your hardware platform. Here is a minimal
25557 QEMU invocation that will boot the result of @command{guix system
25558 vm-image} on x86_64 hardware:
25561 $ qemu-system-x86_64 \
25562 -net user -net nic,model=virtio \
25563 -enable-kvm -m 1024 \
25564 -device virtio-blk,drive=myhd \
25565 -drive if=none,file=/tmp/qemu-image,id=myhd
25568 Here is what each of these options means:
25571 @item qemu-system-x86_64
25572 This specifies the hardware platform to emulate. This should match the
25576 Enable the unprivileged user-mode network stack. The guest OS can
25577 access the host but not vice versa. This is the simplest way to get the
25580 @item -net nic,model=virtio
25581 You must create a network interface of a given model. If you do not
25582 create a NIC, the boot will fail. Assuming your hardware platform is
25583 x86_64, you can get a list of available NIC models by running
25584 @command{qemu-system-x86_64 -net nic,model=help}.
25587 If your system has hardware virtualization extensions, enabling the
25588 virtual machine support (KVM) of the Linux kernel will make things run
25591 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
25593 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
25594 which may be insufficient for some operations.
25596 @item -device virtio-blk,drive=myhd
25597 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
25598 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
25599 better performance than if it were emulating a complete disk drive. See the
25600 QEMU and KVM documentation for more info.
25602 @item -drive if=none,file=/tmp/qemu-image,id=myhd
25603 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
25604 the ``myhd'' drive.
25607 The default @command{run-vm.sh} script that is returned by an invocation of
25608 @command{guix system vm} does not add a @command{-net user} flag by default.
25609 To get network access from within the vm add the @code{(dhcp-client-service)}
25610 to your system definition and start the VM using
25611 @command{`guix system vm config.scm` -net user}. An important caveat of using
25612 @command{-net user} for networking is that @command{ping} will not work, because
25613 it uses the ICMP protocol. You'll have to use a different command to check for
25614 network connectivity, for example @command{guix download}.
25616 @subsection Connecting Through SSH
25620 To enable SSH inside a VM you need to add an SSH server like
25621 @code{openssh-service-type} to your VM (@pxref{Networking Services,
25622 @code{openssh-service-type}}). In addition you need to forward the SSH port,
25623 22 by default, to the host. You can do this with
25626 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
25629 To connect to the VM you can run
25632 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
25635 The @command{-p} tells @command{ssh} the port you want to connect to.
25636 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
25637 every time you modify your @command{config.scm} file and the
25638 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
25639 connection to an unknown host every time you connect.
25641 @subsection Using @command{virt-viewer} with Spice
25643 As an alternative to the default @command{qemu} graphical client you can
25644 use the @command{remote-viewer} from the @command{virt-viewer} package. To
25645 connect pass the @command{-spice port=5930,disable-ticketing} flag to
25646 @command{qemu}. See previous section for further information on how to do this.
25648 Spice also allows you to do some nice stuff like share your clipboard with your
25649 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
25652 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
25653 -chardev spicevmc,name=vdagent,id=vdagent
25654 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
25655 name=com.redhat.spice.0
25658 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
25660 @node Defining Services
25661 @section Defining Services
25663 The previous sections show the available services and how one can combine
25664 them in an @code{operating-system} declaration. But how do we define
25665 them in the first place? And what is a service anyway?
25668 * Service Composition:: The model for composing services.
25669 * Service Types and Services:: Types and services.
25670 * Service Reference:: API reference.
25671 * Shepherd Services:: A particular type of service.
25674 @node Service Composition
25675 @subsection Service Composition
25679 Here we define a @dfn{service} as, broadly, something that extends the
25680 functionality of the operating system. Often a service is a process---a
25681 @dfn{daemon}---started when the system boots: a secure shell server, a
25682 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
25683 whose execution can be triggered by another daemon---e.g., an FTP server
25684 started by @command{inetd} or a D-Bus service activated by
25685 @command{dbus-daemon}. Occasionally, a service does not map to a
25686 daemon. For instance, the ``account'' service collects user accounts
25687 and makes sure they exist when the system runs; the ``udev'' service
25688 collects device management rules and makes them available to the eudev
25689 daemon; the @file{/etc} service populates the @file{/etc} directory
25692 @cindex service extensions
25693 Guix system services are connected by @dfn{extensions}. For instance, the
25694 secure shell service @emph{extends} the Shepherd---the
25695 initialization system, running as PID@tie{}1---by giving it the command
25696 lines to start and stop the secure shell daemon (@pxref{Networking
25697 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
25698 service by passing it its @file{.service} specification, and extends the
25699 udev service by passing it device management rules (@pxref{Desktop
25700 Services, @code{upower-service}}); the Guix daemon service extends the
25701 Shepherd by passing it the command lines to start and stop the daemon,
25702 and extends the account service by passing it a list of required build
25703 user accounts (@pxref{Base Services}).
25705 All in all, services and their ``extends'' relations form a directed
25706 acyclic graph (DAG). If we represent services as boxes and extensions
25707 as arrows, a typical system might provide something like this:
25709 @image{images/service-graph,,5in,Typical service extension graph.}
25711 @cindex system service
25712 At the bottom, we see the @dfn{system service}, which produces the
25713 directory containing everything to run and boot the system, as returned
25714 by the @command{guix system build} command. @xref{Service Reference},
25715 to learn about the other service types shown here.
25716 @xref{system-extension-graph, the @command{guix system extension-graph}
25717 command}, for information on how to generate this representation for a
25718 particular operating system definition.
25720 @cindex service types
25721 Technically, developers can define @dfn{service types} to express these
25722 relations. There can be any number of services of a given type on the
25723 system---for instance, a system running two instances of the GNU secure
25724 shell server (lsh) has two instances of @code{lsh-service-type}, with
25725 different parameters.
25727 The following section describes the programming interface for service
25728 types and services.
25730 @node Service Types and Services
25731 @subsection Service Types and Services
25733 A @dfn{service type} is a node in the DAG described above. Let us start
25734 with a simple example, the service type for the Guix build daemon
25735 (@pxref{Invoking guix-daemon}):
25738 (define guix-service-type
25742 (list (service-extension shepherd-root-service-type guix-shepherd-service)
25743 (service-extension account-service-type guix-accounts)
25744 (service-extension activation-service-type guix-activation)))
25745 (default-value (guix-configuration))))
25749 It defines three things:
25753 A name, whose sole purpose is to make inspection and debugging easier.
25756 A list of @dfn{service extensions}, where each extension designates the
25757 target service type and a procedure that, given the parameters of the
25758 service, returns a list of objects to extend the service of that type.
25760 Every service type has at least one service extension. The only
25761 exception is the @dfn{boot service type}, which is the ultimate service.
25764 Optionally, a default value for instances of this type.
25767 In this example, @code{guix-service-type} extends three services:
25770 @item shepherd-root-service-type
25771 The @code{guix-shepherd-service} procedure defines how the Shepherd
25772 service is extended. Namely, it returns a @code{<shepherd-service>}
25773 object that defines how @command{guix-daemon} is started and stopped
25774 (@pxref{Shepherd Services}).
25776 @item account-service-type
25777 This extension for this service is computed by @code{guix-accounts},
25778 which returns a list of @code{user-group} and @code{user-account}
25779 objects representing the build user accounts (@pxref{Invoking
25782 @item activation-service-type
25783 Here @code{guix-activation} is a procedure that returns a gexp, which is
25784 a code snippet to run at ``activation time''---e.g., when the service is
25788 A service of this type is instantiated like this:
25791 (service guix-service-type
25792 (guix-configuration
25794 (use-substitutes? #f)))
25797 The second argument to the @code{service} form is a value representing
25798 the parameters of this specific service instance.
25799 @xref{guix-configuration-type, @code{guix-configuration}}, for
25800 information about the @code{guix-configuration} data type. When the
25801 value is omitted, the default value specified by
25802 @code{guix-service-type} is used:
25805 (service guix-service-type)
25808 @code{guix-service-type} is quite simple because it extends other
25809 services but is not extensible itself.
25811 @c @subsubsubsection Extensible Service Types
25813 The service type for an @emph{extensible} service looks like this:
25816 (define udev-service-type
25817 (service-type (name 'udev)
25819 (list (service-extension shepherd-root-service-type
25820 udev-shepherd-service)))
25822 (compose concatenate) ;concatenate the list of rules
25823 (extend (lambda (config rules)
25825 (($ <udev-configuration> udev initial-rules)
25826 (udev-configuration
25827 (udev udev) ;the udev package to use
25828 (rules (append initial-rules rules)))))))))
25831 This is the service type for the
25832 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
25833 management daemon}. Compared to the previous example, in addition to an
25834 extension of @code{shepherd-root-service-type}, we see two new fields:
25838 This is the procedure to @dfn{compose} the list of extensions to
25839 services of this type.
25841 Services can extend the udev service by passing it lists of rules; we
25842 compose those extensions simply by concatenating them.
25845 This procedure defines how the value of the service is @dfn{extended} with
25846 the composition of the extensions.
25848 Udev extensions are composed into a list of rules, but the udev service
25849 value is itself a @code{<udev-configuration>} record. So here, we
25850 extend that record by appending the list of rules it contains to the
25851 list of contributed rules.
25854 This is a string giving an overview of the service type. The string can
25855 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
25856 @command{guix system search} command searches these strings and displays
25857 them (@pxref{Invoking guix system}).
25860 There can be only one instance of an extensible service type such as
25861 @code{udev-service-type}. If there were more, the
25862 @code{service-extension} specifications would be ambiguous.
25864 Still here? The next section provides a reference of the programming
25865 interface for services.
25867 @node Service Reference
25868 @subsection Service Reference
25870 We have seen an overview of service types (@pxref{Service Types and
25871 Services}). This section provides a reference on how to manipulate
25872 services and service types. This interface is provided by the
25873 @code{(gnu services)} module.
25875 @deffn {Scheme Procedure} service @var{type} [@var{value}]
25876 Return a new service of @var{type}, a @code{<service-type>} object (see
25877 below.) @var{value} can be any object; it represents the parameters of
25878 this particular service instance.
25880 When @var{value} is omitted, the default value specified by @var{type}
25881 is used; if @var{type} does not specify a default value, an error is
25884 For instance, this:
25887 (service openssh-service-type)
25891 is equivalent to this:
25894 (service openssh-service-type
25895 (openssh-configuration))
25898 In both cases the result is an instance of @code{openssh-service-type}
25899 with the default configuration.
25902 @deffn {Scheme Procedure} service? @var{obj}
25903 Return true if @var{obj} is a service.
25906 @deffn {Scheme Procedure} service-kind @var{service}
25907 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25910 @deffn {Scheme Procedure} service-value @var{service}
25911 Return the value associated with @var{service}. It represents its
25915 Here is an example of how a service is created and manipulated:
25919 (service nginx-service-type
25920 (nginx-configuration
25922 (log-directory log-directory)
25923 (run-directory run-directory)
25924 (file config-file))))
25929 (eq? (service-kind s) nginx-service-type)
25933 The @code{modify-services} form provides a handy way to change the
25934 parameters of some of the services of a list such as
25935 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25936 evaluates to a list of services. Of course, you could always use
25937 standard list combinators such as @code{map} and @code{fold} to do that
25938 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25939 @code{modify-services} simply provides a more concise form for this
25942 @deffn {Scheme Syntax} modify-services @var{services} @
25943 (@var{type} @var{variable} => @var{body}) @dots{}
25945 Modify the services listed in @var{services} according to the given
25946 clauses. Each clause has the form:
25949 (@var{type} @var{variable} => @var{body})
25952 where @var{type} is a service type---e.g.,
25953 @code{guix-service-type}---and @var{variable} is an identifier that is
25954 bound within the @var{body} to the service parameters---e.g., a
25955 @code{guix-configuration} instance---of the original service of that
25958 The @var{body} should evaluate to the new service parameters, which will
25959 be used to configure the new service. This new service will replace the
25960 original in the resulting list. Because a service's service parameters
25961 are created using @code{define-record-type*}, you can write a succinct
25962 @var{body} that evaluates to the new service parameters by using the
25963 @code{inherit} feature that @code{define-record-type*} provides.
25965 @xref{Using the Configuration System}, for example usage.
25969 Next comes the programming interface for service types. This is
25970 something you want to know when writing new service definitions, but not
25971 necessarily when simply looking for ways to customize your
25972 @code{operating-system} declaration.
25974 @deftp {Data Type} service-type
25975 @cindex service type
25976 This is the representation of a @dfn{service type} (@pxref{Service Types
25981 This is a symbol, used only to simplify inspection and debugging.
25983 @item @code{extensions}
25984 A non-empty list of @code{<service-extension>} objects (see below).
25986 @item @code{compose} (default: @code{#f})
25987 If this is @code{#f}, then the service type denotes services that cannot
25988 be extended---i.e., services that do not receive ``values'' from other
25991 Otherwise, it must be a one-argument procedure. The procedure is called
25992 by @code{fold-services} and is passed a list of values collected from
25993 extensions. It may return any single value.
25995 @item @code{extend} (default: @code{#f})
25996 If this is @code{#f}, services of this type cannot be extended.
25998 Otherwise, it must be a two-argument procedure: @code{fold-services}
25999 calls it, passing it the initial value of the service as the first
26000 argument and the result of applying @code{compose} to the extension
26001 values as the second argument. It must return a value that is a valid
26002 parameter value for the service instance.
26005 @xref{Service Types and Services}, for examples.
26008 @deffn {Scheme Procedure} service-extension @var{target-type} @
26010 Return a new extension for services of type @var{target-type}.
26011 @var{compute} must be a one-argument procedure: @code{fold-services}
26012 calls it, passing it the value associated with the service that provides
26013 the extension; it must return a valid value for the target service.
26016 @deffn {Scheme Procedure} service-extension? @var{obj}
26017 Return true if @var{obj} is a service extension.
26020 Occasionally, you might want to simply extend an existing service. This
26021 involves creating a new service type and specifying the extension of
26022 interest, which can be verbose; the @code{simple-service} procedure
26023 provides a shorthand for this.
26025 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
26026 Return a service that extends @var{target} with @var{value}. This works
26027 by creating a singleton service type @var{name}, of which the returned
26028 service is an instance.
26030 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
26034 (simple-service 'my-mcron-job mcron-service-type
26035 #~(job '(next-hour (3)) "guix gc -F 2G"))
26039 At the core of the service abstraction lies the @code{fold-services}
26040 procedure, which is responsible for ``compiling'' a list of services
26041 down to a single directory that contains everything needed to boot and
26042 run the system---the directory shown by the @command{guix system build}
26043 command (@pxref{Invoking guix system}). In essence, it propagates
26044 service extensions down the service graph, updating each node parameters
26045 on the way, until it reaches the root node.
26047 @deffn {Scheme Procedure} fold-services @var{services} @
26048 [#:target-type @var{system-service-type}]
26049 Fold @var{services} by propagating their extensions down to the root of
26050 type @var{target-type}; return the root service adjusted accordingly.
26053 Lastly, the @code{(gnu services)} module also defines several essential
26054 service types, some of which are listed below.
26056 @defvr {Scheme Variable} system-service-type
26057 This is the root of the service graph. It produces the system directory
26058 as returned by the @command{guix system build} command.
26061 @defvr {Scheme Variable} boot-service-type
26062 The type of the ``boot service'', which produces the @dfn{boot script}.
26063 The boot script is what the initial RAM disk runs when booting.
26066 @defvr {Scheme Variable} etc-service-type
26067 The type of the @file{/etc} service. This service is used to create
26068 files under @file{/etc} and can be extended by
26069 passing it name/file tuples such as:
26072 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
26075 In this example, the effect would be to add an @file{/etc/issue} file
26076 pointing to the given file.
26079 @defvr {Scheme Variable} setuid-program-service-type
26080 Type for the ``setuid-program service''. This service collects lists of
26081 executable file names, passed as gexps, and adds them to the set of
26082 setuid-root programs on the system (@pxref{Setuid Programs}).
26085 @defvr {Scheme Variable} profile-service-type
26086 Type of the service that populates the @dfn{system profile}---i.e., the
26087 programs under @file{/run/current-system/profile}. Other services can
26088 extend it by passing it lists of packages to add to the system profile.
26092 @node Shepherd Services
26093 @subsection Shepherd Services
26095 @cindex shepherd services
26097 @cindex init system
26098 The @code{(gnu services shepherd)} module provides a way to define
26099 services managed by the GNU@tie{}Shepherd, which is the
26100 initialization system---the first process that is started when the
26101 system boots, also known as PID@tie{}1
26102 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
26104 Services in the Shepherd can depend on each other. For instance, the
26105 SSH daemon may need to be started after the syslog daemon has been
26106 started, which in turn can only happen once all the file systems have
26107 been mounted. The simple operating system defined earlier (@pxref{Using
26108 the Configuration System}) results in a service graph like this:
26110 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
26112 You can actually generate such a graph for any operating system
26113 definition using the @command{guix system shepherd-graph} command
26114 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
26116 The @code{%shepherd-root-service} is a service object representing
26117 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
26118 by passing it lists of @code{<shepherd-service>} objects.
26120 @deftp {Data Type} shepherd-service
26121 The data type representing a service managed by the Shepherd.
26124 @item @code{provision}
26125 This is a list of symbols denoting what the service provides.
26127 These are the names that may be passed to @command{herd start},
26128 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
26129 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
26130 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
26132 @item @code{requirement} (default: @code{'()})
26133 List of symbols denoting the Shepherd services this one depends on.
26135 @cindex one-shot services, for the Shepherd
26136 @item @code{one-shot?} (default: @code{#f})
26137 Whether this service is @dfn{one-shot}. One-shot services stop immediately
26138 after their @code{start} action has completed. @xref{Slots of services,,,
26139 shepherd, The GNU Shepherd Manual}, for more info.
26141 @item @code{respawn?} (default: @code{#t})
26142 Whether to restart the service when it stops, for instance when the
26143 underlying process dies.
26146 @itemx @code{stop} (default: @code{#~(const #f)})
26147 The @code{start} and @code{stop} fields refer to the Shepherd's
26148 facilities to start and stop processes (@pxref{Service De- and
26149 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
26150 G-expressions that get expanded in the Shepherd configuration file
26151 (@pxref{G-Expressions}).
26153 @item @code{actions} (default: @code{'()})
26154 @cindex actions, of Shepherd services
26155 This is a list of @code{shepherd-action} objects (see below) defining
26156 @dfn{actions} supported by the service, in addition to the standard
26157 @code{start} and @code{stop} actions. Actions listed here become available as
26158 @command{herd} sub-commands:
26161 herd @var{action} @var{service} [@var{arguments}@dots{}]
26164 @item @code{auto-start?} (default: @code{#t})
26165 Whether this service should be started automatically by the Shepherd. If it
26166 is @code{#f} the service has to be started manually with @code{herd start}.
26168 @item @code{documentation}
26169 A documentation string, as shown when running:
26172 herd doc @var{service-name}
26175 where @var{service-name} is one of the symbols in @code{provision}
26176 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
26178 @item @code{modules} (default: @code{%default-modules})
26179 This is the list of modules that must be in scope when @code{start} and
26180 @code{stop} are evaluated.
26185 @deftp {Data Type} shepherd-action
26186 This is the data type that defines additional actions implemented by a
26187 Shepherd service (see above).
26191 Symbol naming the action.
26193 @item documentation
26194 This is a documentation string for the action. It can be viewed by running:
26197 herd doc @var{service} action @var{action}
26201 This should be a gexp that evaluates to a procedure of at least one argument,
26202 which is the ``running value'' of the service (@pxref{Slots of services,,,
26203 shepherd, The GNU Shepherd Manual}).
26206 The following example defines an action called @code{say-hello} that kindly
26212 (documentation "Say hi!")
26213 (procedure #~(lambda (running . args)
26214 (format #t "Hello, friend! arguments: ~s\n"
26219 Assuming this action is added to the @code{example} service, then you can do:
26222 # herd say-hello example
26223 Hello, friend! arguments: ()
26224 # herd say-hello example a b c
26225 Hello, friend! arguments: ("a" "b" "c")
26228 This, as you can see, is a fairly sophisticated way to say hello.
26229 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
26233 @defvr {Scheme Variable} shepherd-root-service-type
26234 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
26236 This is the service type that extensions target when they want to create
26237 shepherd services (@pxref{Service Types and Services}, for an example).
26238 Each extension must pass a list of @code{<shepherd-service>}.
26241 @defvr {Scheme Variable} %shepherd-root-service
26242 This service represents PID@tie{}1.
26246 @node Documentation
26247 @chapter Documentation
26249 @cindex documentation, searching for
26250 @cindex searching for documentation
26251 @cindex Info, documentation format
26253 @cindex manual pages
26254 In most cases packages installed with Guix come with documentation.
26255 There are two main documentation formats: ``Info'', a browseable
26256 hypertext format used for GNU software, and ``manual pages'' (or ``man
26257 pages''), the linear documentation format traditionally found on Unix.
26258 Info manuals are accessed with the @command{info} command or with Emacs,
26259 and man pages are accessed using @command{man}.
26261 You can look for documentation of software installed on your system by
26262 keyword. For example, the following command searches for information
26263 about ``TLS'' in Info manuals:
26267 "(emacs)Network Security" -- STARTTLS
26268 "(emacs)Network Security" -- TLS
26269 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
26270 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
26275 The command below searches for the same keyword in man pages:
26279 SSL (7) - OpenSSL SSL/TLS library
26280 certtool (1) - GnuTLS certificate tool
26284 These searches are purely local to your computer so you have the
26285 guarantee that documentation you find corresponds to what you have
26286 actually installed, you can access it off-line, and your privacy is
26289 Once you have these results, you can view the relevant documentation by
26293 $ info "(gnutls)Core TLS API"
26303 Info manuals contain sections and indices as well as hyperlinks like
26304 those found in Web pages. The @command{info} reader (@pxref{Top, Info
26305 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
26306 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
26307 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
26308 Introduction}, for an introduction to Info navigation.
26310 @node Installing Debugging Files
26311 @chapter Installing Debugging Files
26313 @cindex debugging files
26314 Program binaries, as produced by the GCC compilers for instance, are
26315 typically written in the ELF format, with a section containing
26316 @dfn{debugging information}. Debugging information is what allows the
26317 debugger, GDB, to map binary code to source code; it is required to
26318 debug a compiled program in good conditions.
26320 The problem with debugging information is that is takes up a fair amount
26321 of disk space. For example, debugging information for the GNU C Library
26322 weighs in at more than 60 MiB. Thus, as a user, keeping all the
26323 debugging info of all the installed programs is usually not an option.
26324 Yet, space savings should not come at the cost of an impediment to
26325 debugging---especially in the GNU system, which should make it easier
26326 for users to exert their computing freedom (@pxref{GNU Distribution}).
26328 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
26329 mechanism that allows users to get the best of both worlds: debugging
26330 information can be stripped from the binaries and stored in separate
26331 files. GDB is then able to load debugging information from those files,
26332 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
26335 The GNU distribution takes advantage of this by storing debugging
26336 information in the @code{lib/debug} sub-directory of a separate package
26337 output unimaginatively called @code{debug} (@pxref{Packages with
26338 Multiple Outputs}). Users can choose to install the @code{debug} output
26339 of a package when they need it. For instance, the following command
26340 installs the debugging information for the GNU C Library and for GNU
26344 guix install glibc:debug guile:debug
26347 GDB must then be told to look for debug files in the user's profile, by
26348 setting the @code{debug-file-directory} variable (consider setting it
26349 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
26353 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
26356 From there on, GDB will pick up debugging information from the
26357 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
26359 In addition, you will most likely want GDB to be able to show the source
26360 code being debugged. To do that, you will have to unpack the source
26361 code of the package of interest (obtained with @code{guix build
26362 --source}, @pxref{Invoking guix build}), and to point GDB to that source
26363 directory using the @code{directory} command (@pxref{Source Path,
26364 @code{directory},, gdb, Debugging with GDB}).
26366 @c XXX: keep me up-to-date
26367 The @code{debug} output mechanism in Guix is implemented by the
26368 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
26369 opt-in---debugging information is available only for the packages
26370 with definitions explicitly declaring a @code{debug} output. This may be
26371 changed to opt-out in the future if our build farm servers can handle
26372 the load. To check whether a package has a @code{debug} output, use
26373 @command{guix package --list-available} (@pxref{Invoking guix package}).
26376 @node Security Updates
26377 @chapter Security Updates
26379 @cindex security updates
26380 @cindex security vulnerabilities
26381 Occasionally, important security vulnerabilities are discovered in software
26382 packages and must be patched. Guix developers try hard to keep track of
26383 known vulnerabilities and to apply fixes as soon as possible in the
26384 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
26385 containing only security updates.) The @command{guix lint} tool helps
26386 developers find out about vulnerable versions of software packages in the
26391 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
26392 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
26393 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
26397 @xref{Invoking guix lint}, for more information.
26400 As of version @value{VERSION}, the feature described below is considered
26404 Guix follows a functional
26405 package management discipline (@pxref{Introduction}), which implies
26406 that, when a package is changed, @emph{every package that depends on it}
26407 must be rebuilt. This can significantly slow down the deployment of
26408 fixes in core packages such as libc or Bash, since basically the whole
26409 distribution would need to be rebuilt. Using pre-built binaries helps
26410 (@pxref{Substitutes}), but deployment may still take more time than
26414 To address this, Guix implements @dfn{grafts}, a mechanism that allows
26415 for fast deployment of critical updates without the costs associated
26416 with a whole-distribution rebuild. The idea is to rebuild only the
26417 package that needs to be patched, and then to ``graft'' it onto packages
26418 explicitly installed by the user and that were previously referring to
26419 the original package. The cost of grafting is typically very low, and
26420 order of magnitudes lower than a full rebuild of the dependency chain.
26422 @cindex replacements of packages, for grafts
26423 For instance, suppose a security update needs to be applied to Bash.
26424 Guix developers will provide a package definition for the ``fixed''
26425 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
26426 Packages}). Then, the original package definition is augmented with a
26427 @code{replacement} field pointing to the package containing the bug fix:
26434 (replacement bash-fixed)))
26437 From there on, any package depending directly or indirectly on Bash---as
26438 reported by @command{guix gc --requisites} (@pxref{Invoking guix
26439 gc})---that is installed is automatically ``rewritten'' to refer to
26440 @code{bash-fixed} instead of @code{bash}. This grafting process takes
26441 time proportional to the size of the package, usually less than a
26442 minute for an ``average'' package on a recent machine. Grafting is
26443 recursive: when an indirect dependency requires grafting, then grafting
26444 ``propagates'' up to the package that the user is installing.
26446 Currently, the length of the name and version of the graft and that of
26447 the package it replaces (@code{bash-fixed} and @code{bash} in the example
26448 above) must be equal. This restriction mostly comes from the fact that
26449 grafting works by patching files, including binary files, directly.
26450 Other restrictions may apply: for instance, when adding a graft to a
26451 package providing a shared library, the original shared library and its
26452 replacement must have the same @code{SONAME} and be binary-compatible.
26454 The @option{--no-grafts} command-line option allows you to forcefully
26455 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
26459 guix build bash --no-grafts
26463 returns the store file name of the original Bash, whereas:
26470 returns the store file name of the ``fixed'', replacement Bash. This
26471 allows you to distinguish between the two variants of Bash.
26473 To verify which Bash your whole profile refers to, you can run
26474 (@pxref{Invoking guix gc}):
26477 guix gc -R `readlink -f ~/.guix-profile` | grep bash
26481 @dots{} and compare the store file names that you get with those above.
26482 Likewise for a complete Guix system generation:
26485 guix gc -R `guix system build my-config.scm` | grep bash
26488 Lastly, to check which Bash running processes are using, you can use the
26489 @command{lsof} command:
26492 lsof | grep /gnu/store/.*bash
26496 @node Bootstrapping
26497 @chapter Bootstrapping
26499 @c Adapted from the ELS 2013 paper.
26501 @cindex bootstrapping
26503 Bootstrapping in our context refers to how the distribution gets built
26504 ``from nothing''. Remember that the build environment of a derivation
26505 contains nothing but its declared inputs (@pxref{Introduction}). So
26506 there's an obvious chicken-and-egg problem: how does the first package
26507 get built? How does the first compiler get compiled? Note that this is
26508 a question of interest only to the curious hacker, not to the regular
26509 user, so you can shamelessly skip this section if you consider yourself
26510 a ``regular user''.
26512 @cindex bootstrap binaries
26513 The GNU system is primarily made of C code, with libc at its core. The
26514 GNU build system itself assumes the availability of a Bourne shell and
26515 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
26516 `grep'. Furthermore, build programs---programs that run
26517 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
26518 (@pxref{Derivations}). Consequently, to be able to build anything at
26519 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
26520 Binutils, libc, and the other packages mentioned above---the
26521 @dfn{bootstrap binaries}.
26523 These bootstrap binaries are ``taken for granted'', though we can also
26524 re-create them if needed (more on that later).
26526 @unnumberedsec Preparing to Use the Bootstrap Binaries
26528 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
26529 @c large image, it's hard to scroll. Oh well.
26530 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
26532 The figure above shows the very beginning of the dependency graph of the
26533 distribution, corresponding to the package definitions of the @code{(gnu
26534 packages bootstrap)} module. A similar figure can be generated with
26535 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
26538 guix graph -t derivation \
26539 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
26543 At this level of detail, things are
26544 slightly complex. First, Guile itself consists of an ELF executable,
26545 along with many source and compiled Scheme files that are dynamically
26546 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
26547 tarball shown in this graph. This tarball is part of Guix's ``source''
26548 distribution, and gets inserted into the store with @code{add-to-store}
26549 (@pxref{The Store}).
26551 But how do we write a derivation that unpacks this tarball and adds it
26552 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
26553 derivation---the first one that gets built---uses @code{bash} as its
26554 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
26555 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
26556 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
26557 the Guix source distribution, whose sole purpose is to allow the Guile
26558 tarball to be unpacked.
26560 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
26561 Guile that can be used to run subsequent build programs. Its first task
26562 is to download tarballs containing the other pre-built binaries---this
26563 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
26564 @code{ftp-client.scm} are used for this purpose. The
26565 @code{module-import.drv} derivations import those modules in a directory
26566 in the store, using the original layout. The
26567 @code{module-import-compiled.drv} derivations compile those modules, and
26568 write them in an output directory with the right layout. This
26569 corresponds to the @code{#:modules} argument of
26570 @code{build-expression->derivation} (@pxref{Derivations}).
26572 Finally, the various tarballs are unpacked by the
26573 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
26574 etc., at which point we have a working C tool chain.
26577 @unnumberedsec Building the Build Tools
26579 Bootstrapping is complete when we have a full tool chain that does not
26580 depend on the pre-built bootstrap tools discussed above. This
26581 no-dependency requirement is verified by checking whether the files of
26582 the final tool chain contain references to the @file{/gnu/store}
26583 directories of the bootstrap inputs. The process that leads to this
26584 ``final'' tool chain is described by the package definitions found in
26585 the @code{(gnu packages commencement)} module.
26587 The @command{guix graph} command allows us to ``zoom out'' compared to
26588 the graph above, by looking at the level of package objects instead of
26589 individual derivations---remember that a package may translate to
26590 several derivations, typically one derivation to download its source,
26591 one to build the Guile modules it needs, and one to actually build the
26592 package from source. The command:
26595 guix graph -t bag \
26596 -e '(@@@@ (gnu packages commencement)
26597 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
26601 produces the dependency graph leading to the ``final'' C
26602 library@footnote{You may notice the @code{glibc-intermediate} label,
26603 suggesting that it is not @emph{quite} final, but as a good
26604 approximation, we will consider it final.}, depicted below.
26606 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
26608 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
26609 The first tool that gets built with the bootstrap binaries is
26610 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
26611 for all the following packages. From there Findutils and Diffutils get
26614 Then come the first-stage Binutils and GCC, built as pseudo cross
26615 tools---i.e., with @code{--target} equal to @code{--host}. They are
26616 used to build libc. Thanks to this cross-build trick, this libc is
26617 guaranteed not to hold any reference to the initial tool chain.
26619 From there the final Binutils and GCC (not shown above) are built.
26621 from the final Binutils, and links programs against the just-built libc.
26622 This tool chain is used to build the other packages used by Guix and by
26623 the GNU Build System: Guile, Bash, Coreutils, etc.
26625 And voilà! At this point we have the complete set of build tools that
26626 the GNU Build System expects. These are in the @code{%final-inputs}
26627 variable of the @code{(gnu packages commencement)} module, and are
26628 implicitly used by any package that uses @code{gnu-build-system}
26629 (@pxref{Build Systems, @code{gnu-build-system}}).
26632 @unnumberedsec Building the Bootstrap Binaries
26634 @cindex bootstrap binaries
26635 Because the final tool chain does not depend on the bootstrap binaries,
26636 those rarely need to be updated. Nevertheless, it is useful to have an
26637 automated way to produce them, should an update occur, and this is what
26638 the @code{(gnu packages make-bootstrap)} module provides.
26640 The following command builds the tarballs containing the bootstrap
26641 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
26642 of Coreutils and other basic command-line tools):
26645 guix build bootstrap-tarballs
26648 The generated tarballs are those that should be referred to in the
26649 @code{(gnu packages bootstrap)} module mentioned at the beginning of
26652 Still here? Then perhaps by now you've started to wonder: when do we
26653 reach a fixed point? That is an interesting question! The answer is
26654 unknown, but if you would like to investigate further (and have
26655 significant computational and storage resources to do so), then let us
26658 @unnumberedsec Reducing the Set of Bootstrap Binaries
26660 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
26661 of binary code! Why is that a problem? It's a problem because these
26662 big chunks of binary code are practically non-auditable, which makes it
26663 hard to establish what source code produced them. Every unauditable
26664 binary also leaves us vulnerable to compiler backdoors as described by
26665 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
26667 This is mitigated by the fact that our bootstrap binaries were generated
26668 from an earlier Guix revision. Nevertheless it lacks the level of
26669 transparency that we get in the rest of the package dependency graph,
26670 where Guix always gives us a source-to-binary mapping. Thus, our goal
26671 is to reduce the set of bootstrap binaries to the bare minimum.
26673 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
26674 on-going projects to do that. One of these is about replacing the
26675 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
26676 of increasing complexity, which could be built from source starting from
26677 a simple and auditable assembler. Your help is welcome!
26681 @chapter Porting to a New Platform
26683 As discussed above, the GNU distribution is self-contained, and
26684 self-containment is achieved by relying on pre-built ``bootstrap
26685 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
26686 operating system kernel, CPU architecture, and application binary
26687 interface (ABI). Thus, to port the distribution to a platform that is
26688 not yet supported, one must build those bootstrap binaries, and update
26689 the @code{(gnu packages bootstrap)} module to use them on that platform.
26691 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
26692 When everything goes well, and assuming the GNU tool chain supports the
26693 target platform, this can be as simple as running a command like this
26697 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
26700 For this to work, the @code{glibc-dynamic-linker} procedure in
26701 @code{(gnu packages bootstrap)} must be augmented to return the right
26702 file name for libc's dynamic linker on that platform; likewise,
26703 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
26704 taught about the new platform.
26706 Once these are built, the @code{(gnu packages bootstrap)} module needs
26707 to be updated to refer to these binaries on the target platform. That
26708 is, the hashes and URLs of the bootstrap tarballs for the new platform
26709 must be added alongside those of the currently supported platforms. The
26710 bootstrap Guile tarball is treated specially: it is expected to be
26711 available locally, and @file{gnu/local.mk} has rules to download it for
26712 the supported architectures; a rule for the new platform must be added
26715 In practice, there may be some complications. First, it may be that the
26716 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
26717 above) is not recognized by all the GNU tools. Typically, glibc
26718 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
26719 configure flag (see @code{gcc.scm} for examples of how to handle this).
26720 Second, some of the required packages could fail to build for that
26721 platform. Lastly, the generated binaries could be broken for some
26724 @c *********************************************************************
26725 @include contributing.texi
26727 @c *********************************************************************
26728 @node Acknowledgments
26729 @chapter Acknowledgments
26731 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
26732 which was designed and
26733 implemented by Eelco Dolstra, with contributions from other people (see
26734 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
26735 management, and promoted unprecedented features, such as transactional
26736 package upgrades and rollbacks, per-user profiles, and referentially
26737 transparent build processes. Without this work, Guix would not exist.
26739 The Nix-based software distributions, Nixpkgs and NixOS, have also been
26740 an inspiration for Guix.
26742 GNU@tie{}Guix itself is a collective work with contributions from a
26743 number of people. See the @file{AUTHORS} file in Guix for more
26744 information on these fine people. The @file{THANKS} file lists people
26745 who have helped by reporting bugs, taking care of the infrastructure,
26746 providing artwork and themes, making suggestions, and more---thank you!
26749 @c *********************************************************************
26750 @node GNU Free Documentation License
26751 @appendix GNU Free Documentation License
26752 @cindex license, GNU Free Documentation License
26753 @include fdl-1.3.texi
26755 @c *********************************************************************
26756 @node Concept Index
26757 @unnumbered Concept Index
26760 @node Programming Index
26761 @unnumbered Programming Index
26762 @syncodeindex tp fn
26763 @syncodeindex vr fn
26768 @c Local Variables:
26769 @c ispell-local-dictionary: "american";